fs/ext4/super.c

   1 /*
   2  *  linux/fs/ext4/super.c
   3  *
   4  * Copyright (C) 1992, 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  *
   9  *  from
  10  *
  11  *  linux/fs/minix/inode.c
  12  *
  13  *  Copyright (C) 1991, 1992  Linus Torvalds
  14  *
  15  *  Big-endian to little-endian byte-swapping/bitmaps by
  16  *        David S. Miller (davem@caip.rutgers.edu), 1995
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/string.h>
  21 #include <linux/fs.h>
  22 #include <linux/time.h>
  23 #include <linux/vmalloc.h>
  24 #include <linux/jbd2.h>
  25 #include <linux/slab.h>
  26 #include <linux/init.h>
  27 #include <linux/blkdev.h>
  28 #include <linux/parser.h>
  29 #include <linux/buffer_head.h>
  30 #include <linux/exportfs.h>
  31 #include <linux/vfs.h>
  32 #include <linux/random.h>
  33 #include <linux/mount.h>
  34 #include <linux/namei.h>
  35 #include <linux/quotaops.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/ctype.h>
  39 #include <linux/log2.h>
  40 #include <linux/crc16.h>
  41 #include <asm/uaccess.h>
  42
  43 #include <linux/kthread.h>
  44 #include <linux/freezer.h>
  45
  46 #include "ext4.h"
  47 #include "ext4_jbd2.h"
  48 #include "xattr.h"
  49 #include "acl.h"
  50 #include "mballoc.h"
  51
  52 #define CREATE_TRACE_POINTS
  53 #include <trace/events/ext4.h>
  54
  55 static struct proc_dir_entry *ext4_proc_root;
  56 static struct kset *ext4_kset;
  57 struct ext4_lazy_init *ext4_li_info;
  58 struct mutex ext4_li_mtx;
  59 struct ext4_features *ext4_feat;
  60
  61 static int ext4_load_journal(struct super_block *, struct ext4_super_block *,
  62                              unsigned long journal_devnum);
  63 static int ext4_commit_super(struct super_block *sb, int sync);
  64 static void ext4_mark_recovery_complete(struct super_block *sb,
  65                                         struct ext4_super_block *es);
  66 static void ext4_clear_journal_err(struct super_block *sb,
  67                                    struct ext4_super_block *es);
  68 static int ext4_sync_fs(struct super_block *sb, int wait);
  69 static const char *ext4_decode_error(struct super_block *sb, int errno,
  70                                      char nbuf[16]);
  71 static int ext4_remount(struct super_block *sb, int *flags, char *data);
  72 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf);
  73 static int ext4_unfreeze(struct super_block *sb);
  74 static void ext4_write_super(struct super_block *sb);
  75 static int ext4_freeze(struct super_block *sb);
  76 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
  77                        const char *dev_name, void *data);
  78 static void ext4_destroy_lazyinit_thread(void);
  79 static void ext4_unregister_li_request(struct super_block *sb);
  80
  81 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
  82 static struct file_system_type ext3_fs_type = {
  83         .owner          = THIS_MODULE,
  84         .name           = "ext3",
  85         .mount          = ext4_mount,
  86         .kill_sb        = kill_block_super,
  87         .fs_flags       = FS_REQUIRES_DEV,
  88 };
  89 #define IS_EXT3_SB(sb) ((sb)->s_bdev->bd_holder == &ext3_fs_type)
  90 #else
  91 #define IS_EXT3_SB(sb) (0)
  92 #endif
  93
  94 ext4_fsblk_t ext4_block_bitmap(struct super_block *sb,
  95                                struct ext4_group_desc *bg)
  96 {
  97         return le32_to_cpu(bg->bg_block_bitmap_lo) |
  98                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
  99                  (ext4_fsblk_t)le32_to_cpu(bg->bg_block_bitmap_hi) << 32 : 0);
 100 }
 101
 102 ext4_fsblk_t ext4_inode_bitmap(struct super_block *sb,
 103                                struct ext4_group_desc *bg)
 104 {
 105         return le32_to_cpu(bg->bg_inode_bitmap_lo) |
 106                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 107                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_bitmap_hi) << 32 : 0);
 108 }
 109
 110 ext4_fsblk_t ext4_inode_table(struct super_block *sb,
 111                               struct ext4_group_desc *bg)
 112 {
 113         return le32_to_cpu(bg->bg_inode_table_lo) |
 114                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 115                  (ext4_fsblk_t)le32_to_cpu(bg->bg_inode_table_hi) << 32 : 0);
 116 }
 117
 118 __u32 ext4_free_blks_count(struct super_block *sb,
 119                               struct ext4_group_desc *bg)
 120 {
 121         return le16_to_cpu(bg->bg_free_blocks_count_lo) |
 122                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 123                  (__u32)le16_to_cpu(bg->bg_free_blocks_count_hi) << 16 : 0);
 124 }
 125
 126 __u32 ext4_free_inodes_count(struct super_block *sb,
 127                               struct ext4_group_desc *bg)
 128 {
 129         return le16_to_cpu(bg->bg_free_inodes_count_lo) |
 130                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 131                  (__u32)le16_to_cpu(bg->bg_free_inodes_count_hi) << 16 : 0);
 132 }
 133
 134 __u32 ext4_used_dirs_count(struct super_block *sb,
 135                               struct ext4_group_desc *bg)
 136 {
 137         return le16_to_cpu(bg->bg_used_dirs_count_lo) |
 138                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 139                  (__u32)le16_to_cpu(bg->bg_used_dirs_count_hi) << 16 : 0);
 140 }
 141
 142 __u32 ext4_itable_unused_count(struct super_block *sb,
 143                               struct ext4_group_desc *bg)
 144 {
 145         return le16_to_cpu(bg->bg_itable_unused_lo) |
 146                 (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT ?
 147                  (__u32)le16_to_cpu(bg->bg_itable_unused_hi) << 16 : 0);
 148 }
 149
 150 void ext4_block_bitmap_set(struct super_block *sb,
 151                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 152 {
 153         bg->bg_block_bitmap_lo = cpu_to_le32((u32)blk);
 154         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 155                 bg->bg_block_bitmap_hi = cpu_to_le32(blk >> 32);
 156 }
 157
 158 void ext4_inode_bitmap_set(struct super_block *sb,
 159                            struct ext4_group_desc *bg, ext4_fsblk_t blk)
 160 {
 161         bg->bg_inode_bitmap_lo  = cpu_to_le32((u32)blk);
 162         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 163                 bg->bg_inode_bitmap_hi = cpu_to_le32(blk >> 32);
 164 }
 165
 166 void ext4_inode_table_set(struct super_block *sb,
 167                           struct ext4_group_desc *bg, ext4_fsblk_t blk)
 168 {
 169         bg->bg_inode_table_lo = cpu_to_le32((u32)blk);
 170         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 171                 bg->bg_inode_table_hi = cpu_to_le32(blk >> 32);
 172 }
 173
 174 void ext4_free_blks_set(struct super_block *sb,
 175                           struct ext4_group_desc *bg, __u32 count)
 176 {
 177         bg->bg_free_blocks_count_lo = cpu_to_le16((__u16)count);
 178         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 179                 bg->bg_free_blocks_count_hi = cpu_to_le16(count >> 16);
 180 }
 181
 182 void ext4_free_inodes_set(struct super_block *sb,
 183                           struct ext4_group_desc *bg, __u32 count)
 184 {
 185         bg->bg_free_inodes_count_lo = cpu_to_le16((__u16)count);
 186         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 187                 bg->bg_free_inodes_count_hi = cpu_to_le16(count >> 16);
 188 }
 189
 190 void ext4_used_dirs_set(struct super_block *sb,
 191                           struct ext4_group_desc *bg, __u32 count)
 192 {
 193         bg->bg_used_dirs_count_lo = cpu_to_le16((__u16)count);
 194         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 195                 bg->bg_used_dirs_count_hi = cpu_to_le16(count >> 16);
 196 }
 197
 198 void ext4_itable_unused_set(struct super_block *sb,
 199                           struct ext4_group_desc *bg, __u32 count)
 200 {
 201         bg->bg_itable_unused_lo = cpu_to_le16((__u16)count);
 202         if (EXT4_DESC_SIZE(sb) >= EXT4_MIN_DESC_SIZE_64BIT)
 203                 bg->bg_itable_unused_hi = cpu_to_le16(count >> 16);
 204 }
 205
 206
 207 /* Just increment the non-pointer handle value */
 208 static handle_t *ext4_get_nojournal(void)
 209 {
 210         handle_t *handle = current->journal_info;
 211         unsigned long ref_cnt = (unsigned long)handle;
 212
 213         BUG_ON(ref_cnt >= EXT4_NOJOURNAL_MAX_REF_COUNT);
 214
 215         ref_cnt++;
 216         handle = (handle_t *)ref_cnt;
 217
 218         current->journal_info = handle;
 219         return handle;
 220 }
 221
 222
 223 /* Decrement the non-pointer handle value */
 224 static void ext4_put_nojournal(handle_t *handle)
 225 {
 226         unsigned long ref_cnt = (unsigned long)handle;
 227
 228         BUG_ON(ref_cnt == 0);
 229
 230         ref_cnt--;
 231         handle = (handle_t *)ref_cnt;
 232
 233         current->journal_info = handle;
 234 }
 235
 236 /*
 237  * Wrappers for jbd2_journal_start/end.
 238  *
 239  * The only special thing we need to do here is to make sure that all
 240  * journal_end calls result in the superblock being marked dirty, so
 241  * that sync() will call the filesystem's write_super callback if
 242  * appropriate.
 243  */
 244 handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks)
 245 {
 246         journal_t *journal;
 247
 248         if (sb->s_flags & MS_RDONLY)
 249                 return ERR_PTR(-EROFS);
 250
 251         vfs_check_frozen(sb, SB_FREEZE_TRANS);
 252         /* Special case here: if the journal has aborted behind our
 253          * backs (eg. EIO in the commit thread), then we still need to
 254          * take the FS itself readonly cleanly. */
 255         journal = EXT4_SB(sb)->s_journal;
 256         if (journal) {
 257                 if (is_journal_aborted(journal)) {
 258                         ext4_abort(sb, "Detected aborted journal");
 259                         return ERR_PTR(-EROFS);
 260                 }
 261                 return jbd2_journal_start(journal, nblocks);
 262         }
 263         return ext4_get_nojournal();
 264 }
 265
 266 /*
 267  * The only special thing we need to do here is to make sure that all
 268  * jbd2_journal_stop calls result in the superblock being marked dirty, so
 269  * that sync() will call the filesystem's write_super callback if
 270  * appropriate.
 271  */
 272 int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle)
 273 {
 274         struct super_block *sb;
 275         int err;
 276         int rc;
 277
 278         if (!ext4_handle_valid(handle)) {
 279                 ext4_put_nojournal(handle);
 280                 return 0;
 281         }
 282         sb = handle->h_transaction->t_journal->j_private;
 283         err = handle->h_err;
 284         rc = jbd2_journal_stop(handle);
 285
 286         if (!err)
 287                 err = rc;
 288         if (err)
 289                 __ext4_std_error(sb, where, line, err);
 290         return err;
 291 }
 292
 293 void ext4_journal_abort_handle(const char *caller, unsigned int line,
 294                                const char *err_fn, struct buffer_head *bh,
 295                                handle_t *handle, int err)
 296 {
 297         char nbuf[16];
 298         const char *errstr = ext4_decode_error(NULL, err, nbuf);
 299
 300         BUG_ON(!ext4_handle_valid(handle));
 301
 302         if (bh)
 303                 BUFFER_TRACE(bh, "abort");
 304
 305         if (!handle->h_err)
 306                 handle->h_err = err;
 307
 308         if (is_handle_aborted(handle))
 309                 return;
 310
 311         printk(KERN_ERR "%s:%d: aborting transaction: %s in %s\n",
 312                caller, line, errstr, err_fn);
 313
 314         jbd2_journal_abort_handle(handle);
 315 }
 316
 317 static void __save_error_info(struct super_block *sb, const char *func,
 318                             unsigned int line)
 319 {
 320         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 321
 322         EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
 323         es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
 324         es->s_last_error_time = cpu_to_le32(get_seconds());
 325         strncpy(es->s_last_error_func, func, sizeof(es->s_last_error_func));
 326         es->s_last_error_line = cpu_to_le32(line);
 327         if (!es->s_first_error_time) {
 328                 es->s_first_error_time = es->s_last_error_time;
 329                 strncpy(es->s_first_error_func, func,
 330                         sizeof(es->s_first_error_func));
 331                 es->s_first_error_line = cpu_to_le32(line);
 332                 es->s_first_error_ino = es->s_last_error_ino;
 333                 es->s_first_error_block = es->s_last_error_block;
 334         }
 335         /*
 336          * Start the daily error reporting function if it hasn't been
 337          * started already
 338          */
 339         if (!es->s_error_count)
 340                 mod_timer(&EXT4_SB(sb)->s_err_report, jiffies + 24*60*60*HZ);
 341         es->s_error_count = cpu_to_le32(le32_to_cpu(es->s_error_count) + 1);
 342 }
 343
 344 static void save_error_info(struct super_block *sb, const char *func,
 345                             unsigned int line)
 346 {
 347         __save_error_info(sb, func, line);
 348         ext4_commit_super(sb, 1);
 349 }
 350
 351
 352 /* Deal with the reporting of failure conditions on a filesystem such as
 353  * inconsistencies detected or read IO failures.
 354  *
 355  * On ext2, we can store the error state of the filesystem in the
 356  * superblock.  That is not possible on ext4, because we may have other
 357  * write ordering constraints on the superblock which prevent us from
 358  * writing it out straight away; and given that the journal is about to
 359  * be aborted, we can't rely on the current, or future, transactions to
 360  * write out the superblock safely.
 361  *
 362  * We'll just use the jbd2_journal_abort() error code to record an error in
 363  * the journal instead.  On recovery, the journal will complain about
 364  * that error until we've noted it down and cleared it.
 365  */
 366
 367 static void ext4_handle_error(struct super_block *sb)
 368 {
 369         if (sb->s_flags & MS_RDONLY)
 370                 return;
 371
 372         if (!test_opt(sb, ERRORS_CONT)) {
 373                 journal_t *journal = EXT4_SB(sb)->s_journal;
 374
 375                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 376                 if (journal)
 377                         jbd2_journal_abort(journal, -EIO);
 378         }
 379         if (test_opt(sb, ERRORS_RO)) {
 380                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 381                 sb->s_flags |= MS_RDONLY;
 382         }
 383         if (test_opt(sb, ERRORS_PANIC))
 384                 panic("EXT4-fs (device %s): panic forced after error\n",
 385                         sb->s_id);
 386 }
 387
 388 void __ext4_error(struct super_block *sb, const char *function,
 389                   unsigned int line, const char *fmt, ...)
 390 {
 391         struct va_format vaf;
 392         va_list args;
 393
 394         va_start(args, fmt);
 395         vaf.fmt = fmt;
 396         vaf.va = &args;
 397         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: comm %s: %pV\n",
 398                sb->s_id, function, line, current->comm, &vaf);
 399         va_end(args);
 400
 401         ext4_handle_error(sb);
 402 }
 403
 404 void ext4_error_inode(struct inode *inode, const char *function,
 405                       unsigned int line, ext4_fsblk_t block,
 406                       const char *fmt, ...)
 407 {
 408         va_list args;
 409         struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
 410
 411         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 412         es->s_last_error_block = cpu_to_le64(block);
 413         save_error_info(inode->i_sb, function, line);
 414         va_start(args, fmt);
 415         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: inode #%lu: ",
 416                inode->i_sb->s_id, function, line, inode->i_ino);
 417         if (block)
 418                 printk("block %llu: ", block);
 419         printk("comm %s: ", current->comm);
 420         vprintk(fmt, args);
 421         printk("\n");
 422         va_end(args);
 423
 424         ext4_handle_error(inode->i_sb);
 425 }
 426
 427 void ext4_error_file(struct file *file, const char *function,
 428                      unsigned int line, const char *fmt, ...)
 429 {
 430         va_list args;
 431         struct ext4_super_block *es;
 432         struct inode *inode = file->f_dentry->d_inode;
 433         char pathname[80], *path;
 434
 435         es = EXT4_SB(inode->i_sb)->s_es;
 436         es->s_last_error_ino = cpu_to_le32(inode->i_ino);
 437         save_error_info(inode->i_sb, function, line);
 438         va_start(args, fmt);
 439         path = d_path(&(file->f_path), pathname, sizeof(pathname));
 440         if (!path)
 441                 path = "(unknown)";
 442         printk(KERN_CRIT
 443                "EXT4-fs error (device %s): %s:%d: inode #%lu "
 444                "(comm %s path %s): ",
 445                inode->i_sb->s_id, function, line, inode->i_ino,
 446                current->comm, path);
 447         vprintk(fmt, args);
 448         printk("\n");
 449         va_end(args);
 450
 451         ext4_handle_error(inode->i_sb);
 452 }
 453
 454 static const char *ext4_decode_error(struct super_block *sb, int errno,
 455                                      char nbuf[16])
 456 {
 457         char *errstr = NULL;
 458
 459         switch (errno) {
 460         case -EIO:
 461                 errstr = "IO failure";
 462                 break;
 463         case -ENOMEM:
 464                 errstr = "Out of memory";
 465                 break;
 466         case -EROFS:
 467                 if (!sb || (EXT4_SB(sb)->s_journal &&
 468                             EXT4_SB(sb)->s_journal->j_flags & JBD2_ABORT))
 469                         errstr = "Journal has aborted";
 470                 else
 471                         errstr = "Readonly filesystem";
 472                 break;
 473         default:
 474                 /* If the caller passed in an extra buffer for unknown
 475                  * errors, textualise them now.  Else we just return
 476                  * NULL. */
 477                 if (nbuf) {
 478                         /* Check for truncated error codes... */
 479                         if (snprintf(nbuf, 16, "error %d", -errno) >= 0)
 480                                 errstr = nbuf;
 481                 }
 482                 break;
 483         }
 484
 485         return errstr;
 486 }
 487
 488 /* __ext4_std_error decodes expected errors from journaling functions
 489  * automatically and invokes the appropriate error response.  */
 490
 491 void __ext4_std_error(struct super_block *sb, const char *function,
 492                       unsigned int line, int errno)
 493 {
 494         char nbuf[16];
 495         const char *errstr;
 496
 497         /* Special case: if the error is EROFS, and we're not already
 498          * inside a transaction, then there's really no point in logging
 499          * an error. */
 500         if (errno == -EROFS && journal_current_handle() == NULL &&
 501             (sb->s_flags & MS_RDONLY))
 502                 return;
 503
 504         errstr = ext4_decode_error(sb, errno, nbuf);
 505         printk(KERN_CRIT "EXT4-fs error (device %s) in %s:%d: %s\n",
 506                sb->s_id, function, line, errstr);
 507         save_error_info(sb, function, line);
 508
 509         ext4_handle_error(sb);
 510 }
 511
 512 /*
 513  * ext4_abort is a much stronger failure handler than ext4_error.  The
 514  * abort function may be used to deal with unrecoverable failures such
 515  * as journal IO errors or ENOMEM at a critical moment in log management.
 516  *
 517  * We unconditionally force the filesystem into an ABORT|READONLY state,
 518  * unless the error response on the fs has been set to panic in which
 519  * case we take the easy way out and panic immediately.
 520  */
 521
 522 void __ext4_abort(struct super_block *sb, const char *function,
 523                 unsigned int line, const char *fmt, ...)
 524 {
 525         va_list args;
 526
 527         save_error_info(sb, function, line);
 528         va_start(args, fmt);
 529         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: ", sb->s_id,
 530                function, line);
 531         vprintk(fmt, args);
 532         printk("\n");
 533         va_end(args);
 534
 535         if ((sb->s_flags & MS_RDONLY) == 0) {
 536                 ext4_msg(sb, KERN_CRIT, "Remounting filesystem read-only");
 537                 sb->s_flags |= MS_RDONLY;
 538                 EXT4_SB(sb)->s_mount_flags |= EXT4_MF_FS_ABORTED;
 539                 if (EXT4_SB(sb)->s_journal)
 540                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
 541                 save_error_info(sb, function, line);
 542         }
 543         if (test_opt(sb, ERRORS_PANIC))
 544                 panic("EXT4-fs panic from previous error\n");
 545 }
 546
 547 void ext4_msg(struct super_block *sb, const char *prefix, const char *fmt, ...)
 548 {
 549         struct va_format vaf;
 550         va_list args;
 551
 552         va_start(args, fmt);
 553         vaf.fmt = fmt;
 554         vaf.va = &args;
 555         printk("%sEXT4-fs (%s): %pV\n", prefix, sb->s_id, &vaf);
 556         va_end(args);
 557 }
 558
 559 void __ext4_warning(struct super_block *sb, const char *function,
 560                     unsigned int line, const char *fmt, ...)
 561 {
 562         struct va_format vaf;
 563         va_list args;
 564
 565         va_start(args, fmt);
 566         vaf.fmt = fmt;
 567         vaf.va = &args;
 568         printk(KERN_WARNING "EXT4-fs warning (device %s): %s:%d: %pV\n",
 569                sb->s_id, function, line, &vaf);
 570         va_end(args);
 571 }
 572
 573 void __ext4_grp_locked_error(const char *function, unsigned int line,
 574                              struct super_block *sb, ext4_group_t grp,
 575                              unsigned long ino, ext4_fsblk_t block,
 576                              const char *fmt, ...)
 577 __releases(bitlock)
 578 __acquires(bitlock)
 579 {
 580         struct va_format vaf;
 581         va_list args;
 582         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 583
 584         es->s_last_error_ino = cpu_to_le32(ino);
 585         es->s_last_error_block = cpu_to_le64(block);
 586         __save_error_info(sb, function, line);
 587
 588         va_start(args, fmt);
 589
 590         vaf.fmt = fmt;
 591         vaf.va = &args;
 592         printk(KERN_CRIT "EXT4-fs error (device %s): %s:%d: group %u",
 593                sb->s_id, function, line, grp);
 594         if (ino)
 595                 printk(KERN_CONT "inode %lu: ", ino);
 596         if (block)
 597                 printk(KERN_CONT "block %llu:", (unsigned long long) block);
 598         printk(KERN_CONT "%pV\n", &vaf);
 599         va_end(args);
 600
 601         if (test_opt(sb, ERRORS_CONT)) {
 602                 ext4_commit_super(sb, 0);
 603                 return;
 604         }
 605
 606         ext4_unlock_group(sb, grp);
 607         ext4_handle_error(sb);
 608         /*
 609          * We only get here in the ERRORS_RO case; relocking the group
 610          * may be dangerous, but nothing bad will happen since the
 611          * filesystem will have already been marked read/only and the
 612          * journal has been aborted.  We return 1 as a hint to callers
 613          * who might what to use the return value from
 614          * ext4_grp_locked_error() to distinguish beween the
 615          * ERRORS_CONT and ERRORS_RO case, and perhaps return more
 616          * aggressively from the ext4 function in question, with a
 617          * more appropriate error code.
 618          */
 619         ext4_lock_group(sb, grp);
 620         return;
 621 }
 622
 623 void ext4_update_dynamic_rev(struct super_block *sb)
 624 {
 625         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
 626
 627         if (le32_to_cpu(es->s_rev_level) > EXT4_GOOD_OLD_REV)
 628                 return;
 629
 630         ext4_warning(sb,
 631                      "updating to rev %d because of new feature flag, "
 632                      "running e2fsck is recommended",
 633                      EXT4_DYNAMIC_REV);
 634
 635         es->s_first_ino = cpu_to_le32(EXT4_GOOD_OLD_FIRST_INO);
 636         es->s_inode_size = cpu_to_le16(EXT4_GOOD_OLD_INODE_SIZE);
 637         es->s_rev_level = cpu_to_le32(EXT4_DYNAMIC_REV);
 638         /* leave es->s_feature_*compat flags alone */
 639         /* es->s_uuid will be set by e2fsck if empty */
 640
 641         /*
 642          * The rest of the superblock fields should be zero, and if not it
 643          * means they are likely already in use, so leave them alone.  We
 644          * can leave it up to e2fsck to clean up any inconsistencies there.
 645          */
 646 }
 647
 648 /*
 649  * Open the external journal device
 650  */
 651 static struct block_device *ext4_blkdev_get(dev_t dev, struct super_block *sb)
 652 {
 653         struct block_device *bdev;
 654         char b[BDEVNAME_SIZE];
 655
 656         bdev = open_by_devnum(dev, FMODE_READ|FMODE_WRITE);
 657         if (IS_ERR(bdev))
 658                 goto fail;
 659         return bdev;
 660
 661 fail:
 662         ext4_msg(sb, KERN_ERR, "failed to open journal device %s: %ld",
 663                         __bdevname(dev, b), PTR_ERR(bdev));
 664         return NULL;
 665 }
 666
 667 /*
 668  * Release the journal device
 669  */
 670 static int ext4_blkdev_put(struct block_device *bdev)
 671 {
 672         bd_release(bdev);
 673         return blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
 674 }
 675
 676 static int ext4_blkdev_remove(struct ext4_sb_info *sbi)
 677 {
 678         struct block_device *bdev;
 679         int ret = -ENODEV;
 680
 681         bdev = sbi->journal_bdev;
 682         if (bdev) {
 683                 ret = ext4_blkdev_put(bdev);
 684                 sbi->journal_bdev = NULL;
 685         }
 686         return ret;
 687 }
 688
 689 static inline struct inode *orphan_list_entry(struct list_head *l)
 690 {
 691         return &list_entry(l, struct ext4_inode_info, i_orphan)->vfs_inode;
 692 }
 693
 694 static void dump_orphan_list(struct super_block *sb, struct ext4_sb_info *sbi)
 695 {
 696         struct list_head *l;
 697
 698         ext4_msg(sb, KERN_ERR, "sb orphan head is %d",
 699                  le32_to_cpu(sbi->s_es->s_last_orphan));
 700
 701         printk(KERN_ERR "sb_info orphan list:\n");
 702         list_for_each(l, &sbi->s_orphan) {
 703                 struct inode *inode = orphan_list_entry(l);
 704                 printk(KERN_ERR "  "
 705                        "inode %s:%lu at %p: mode %o, nlink %d, next %d\n",
 706                        inode->i_sb->s_id, inode->i_ino, inode,
 707                        inode->i_mode, inode->i_nlink,
 708                        NEXT_ORPHAN(inode));
 709         }
 710 }
 711
 712 static void ext4_put_super(struct super_block *sb)
 713 {
 714         struct ext4_sb_info *sbi = EXT4_SB(sb);
 715         struct ext4_super_block *es = sbi->s_es;
 716         int i, err;
 717
 718         ext4_unregister_li_request(sb);
 719         dquot_disable(sb, -1, DQUOT_USAGE_ENABLED | DQUOT_LIMITS_ENABLED);
 720
 721         flush_workqueue(sbi->dio_unwritten_wq);
 722         destroy_workqueue(sbi->dio_unwritten_wq);
 723
 724         lock_super(sb);
 725         if (sb->s_dirt)
 726                 ext4_commit_super(sb, 1);
 727
 728         if (sbi->s_journal) {
 729                 err = jbd2_journal_destroy(sbi->s_journal);
 730                 sbi->s_journal = NULL;
 731                 if (err < 0)
 732                         ext4_abort(sb, "Couldn't clean up the journal");
 733         }
 734
 735         del_timer(&sbi->s_err_report);
 736         ext4_release_system_zone(sb);
 737         ext4_mb_release(sb);
 738         ext4_ext_release(sb);
 739         ext4_xattr_put_super(sb);
 740
 741         if (!(sb->s_flags & MS_RDONLY)) {
 742                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
 743                 es->s_state = cpu_to_le16(sbi->s_mount_state);
 744                 ext4_commit_super(sb, 1);
 745         }
 746         if (sbi->s_proc) {
 747                 remove_proc_entry(sb->s_id, ext4_proc_root);
 748         }
 749         kobject_del(&sbi->s_kobj);
 750
 751         for (i = 0; i < sbi->s_gdb_count; i++)
 752                 brelse(sbi->s_group_desc[i]);
 753         kfree(sbi->s_group_desc);
 754         if (is_vmalloc_addr(sbi->s_flex_groups))
 755                 vfree(sbi->s_flex_groups);
 756         else
 757                 kfree(sbi->s_flex_groups);
 758         percpu_counter_destroy(&sbi->s_freeblocks_counter);
 759         percpu_counter_destroy(&sbi->s_freeinodes_counter);
 760         percpu_counter_destroy(&sbi->s_dirs_counter);
 761         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
 762         brelse(sbi->s_sbh);
 763 #ifdef CONFIG_QUOTA
 764         for (i = 0; i < MAXQUOTAS; i++)
 765                 kfree(sbi->s_qf_names[i]);
 766 #endif
 767
 768         /* Debugging code just in case the in-memory inode orphan list
 769          * isn't empty.  The on-disk one can be non-empty if we've
 770          * detected an error and taken the fs readonly, but the
 771          * in-memory list had better be clean by this point. */
 772         if (!list_empty(&sbi->s_orphan))
 773                 dump_orphan_list(sb, sbi);
 774         J_ASSERT(list_empty(&sbi->s_orphan));
 775
 776         invalidate_bdev(sb->s_bdev);
 777         if (sbi->journal_bdev && sbi->journal_bdev != sb->s_bdev) {
 778                 /*
 779                  * Invalidate the journal device's buffers.  We don't want them
 780                  * floating about in memory - the physical journal device may
 781                  * hotswapped, and it breaks the `ro-after' testing code.
 782                  */
 783                 sync_blockdev(sbi->journal_bdev);
 784                 invalidate_bdev(sbi->journal_bdev);
 785                 ext4_blkdev_remove(sbi);
 786         }
 787         sb->s_fs_info = NULL;
 788         /*
 789          * Now that we are completely done shutting down the
 790          * superblock, we need to actually destroy the kobject.
 791          */
 792         unlock_super(sb);
 793         kobject_put(&sbi->s_kobj);
 794         wait_for_completion(&sbi->s_kobj_unregister);
 795         kfree(sbi->s_blockgroup_lock);
 796         kfree(sbi);
 797 }
 798
 799 static struct kmem_cache *ext4_inode_cachep;
 800
 801 /*
 802  * Called inside transaction, so use GFP_NOFS
 803  */
 804 static struct inode *ext4_alloc_inode(struct super_block *sb)
 805 {
 806         struct ext4_inode_info *ei;
 807
 808         ei = kmem_cache_alloc(ext4_inode_cachep, GFP_NOFS);
 809         if (!ei)
 810                 return NULL;
 811
 812         ei->vfs_inode.i_version = 1;
 813         ei->vfs_inode.i_data.writeback_index = 0;
 814         memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
 815         INIT_LIST_HEAD(&ei->i_prealloc_list);
 816         spin_lock_init(&ei->i_prealloc_lock);
 817         /*
 818          * Note:  We can be called before EXT4_SB(sb)->s_journal is set,
 819          * therefore it can be null here.  Don't check it, just initialize
 820          * jinode.
 821          */
 822         jbd2_journal_init_jbd_inode(&ei->jinode, &ei->vfs_inode);
 823         ei->i_reserved_data_blocks = 0;
 824         ei->i_reserved_meta_blocks = 0;
 825         ei->i_allocated_meta_blocks = 0;
 826         ei->i_da_metadata_calc_len = 0;
 827         ei->i_delalloc_reserved_flag = 0;
 828         spin_lock_init(&(ei->i_block_reservation_lock));
 829 #ifdef CONFIG_QUOTA
 830         ei->i_reserved_quota = 0;
 831 #endif
 832         INIT_LIST_HEAD(&ei->i_completed_io_list);
 833         spin_lock_init(&ei->i_completed_io_lock);
 834         ei->cur_aio_dio = NULL;
 835         ei->i_sync_tid = 0;
 836         ei->i_datasync_tid = 0;
 837         atomic_set(&ei->i_ioend_count, 0);
 838
 839         return &ei->vfs_inode;
 840 }
 841
 842 static int ext4_drop_inode(struct inode *inode)
 843 {
 844         int drop = generic_drop_inode(inode);
 845
 846         trace_ext4_drop_inode(inode, drop);
 847         return drop;
 848 }
 849
 850 static void ext4_destroy_inode(struct inode *inode)
 851 {
 852         ext4_ioend_wait(inode);
 853         if (!list_empty(&(EXT4_I(inode)->i_orphan))) {
 854                 ext4_msg(inode->i_sb, KERN_ERR,
 855                          "Inode %lu (%p): orphan list check failed!",
 856                          inode->i_ino, EXT4_I(inode));
 857                 print_hex_dump(KERN_INFO, "", DUMP_PREFIX_ADDRESS, 16, 4,
 858                                 EXT4_I(inode), sizeof(struct ext4_inode_info),
 859                                 true);
 860                 dump_stack();
 861         }
 862         kmem_cache_free(ext4_inode_cachep, EXT4_I(inode));
 863 }
 864
 865 static void init_once(void *foo)
 866 {
 867         struct ext4_inode_info *ei = (struct ext4_inode_info *) foo;
 868
 869         INIT_LIST_HEAD(&ei->i_orphan);
 870 #ifdef CONFIG_EXT4_FS_XATTR
 871         init_rwsem(&ei->xattr_sem);
 872 #endif
 873         init_rwsem(&ei->i_data_sem);
 874         inode_init_once(&ei->vfs_inode);
 875 }
 876
 877 static int init_inodecache(void)
 878 {
 879         ext4_inode_cachep = kmem_cache_create("ext4_inode_cache",
 880                                              sizeof(struct ext4_inode_info),
 881                                              0, (SLAB_RECLAIM_ACCOUNT|
 882                                                 SLAB_MEM_SPREAD),
 883                                              init_once);
 884         if (ext4_inode_cachep == NULL)
 885                 return -ENOMEM;
 886         return 0;
 887 }
 888
 889 static void destroy_inodecache(void)
 890 {
 891         kmem_cache_destroy(ext4_inode_cachep);
 892 }
 893
 894 void ext4_clear_inode(struct inode *inode)
 895 {
 896         invalidate_inode_buffers(inode);
 897         end_writeback(inode);
 898         dquot_drop(inode);
 899         ext4_discard_preallocations(inode);
 900         if (EXT4_JOURNAL(inode))
 901                 jbd2_journal_release_jbd_inode(EXT4_SB(inode->i_sb)->s_journal,
 902                                        &EXT4_I(inode)->jinode);
 903 }
 904
 905 static inline void ext4_show_quota_options(struct seq_file *seq,
 906                                            struct super_block *sb)
 907 {
 908 #if defined(CONFIG_QUOTA)
 909         struct ext4_sb_info *sbi = EXT4_SB(sb);
 910
 911         if (sbi->s_jquota_fmt) {
 912                 char *fmtname = "";
 913
 914                 switch (sbi->s_jquota_fmt) {
 915                 case QFMT_VFS_OLD:
 916                         fmtname = "vfsold";
 917                         break;
 918                 case QFMT_VFS_V0:
 919                         fmtname = "vfsv0";
 920                         break;
 921                 case QFMT_VFS_V1:
 922                         fmtname = "vfsv1";
 923                         break;
 924                 }
 925                 seq_printf(seq, ",jqfmt=%s", fmtname);
 926         }
 927
 928         if (sbi->s_qf_names[USRQUOTA])
 929                 seq_printf(seq, ",usrjquota=%s", sbi->s_qf_names[USRQUOTA]);
 930
 931         if (sbi->s_qf_names[GRPQUOTA])
 932                 seq_printf(seq, ",grpjquota=%s", sbi->s_qf_names[GRPQUOTA]);
 933
 934         if (test_opt(sb, USRQUOTA))
 935                 seq_puts(seq, ",usrquota");
 936
 937         if (test_opt(sb, GRPQUOTA))
 938                 seq_puts(seq, ",grpquota");
 939 #endif
 940 }
 941
 942 /*
 943  * Show an option if
 944  *  - it's set to a non-default value OR
 945  *  - if the per-sb default is different from the global default
 946  */
 947 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 948 {
 949         int def_errors;
 950         unsigned long def_mount_opts;
 951         struct super_block *sb = vfs->mnt_sb;
 952         struct ext4_sb_info *sbi = EXT4_SB(sb);
 953         struct ext4_super_block *es = sbi->s_es;
 954
 955         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
 956         def_errors     = le16_to_cpu(es->s_errors);
 957
 958         if (sbi->s_sb_block != 1)
 959                 seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 960         if (test_opt(sb, MINIX_DF))
 961                 seq_puts(seq, ",minixdf");
 962         if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 963                 seq_puts(seq, ",grpid");
 964         if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 965                 seq_puts(seq, ",nogrpid");
 966         if (sbi->s_resuid != EXT4_DEF_RESUID ||
 967             le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID) {
 968                 seq_printf(seq, ",resuid=%u", sbi->s_resuid);
 969         }
 970         if (sbi->s_resgid != EXT4_DEF_RESGID ||
 971             le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 972                 seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 973         }
 974         if (test_opt(sb, ERRORS_RO)) {
 975                 if (def_errors == EXT4_ERRORS_PANIC ||
 976                     def_errors == EXT4_ERRORS_CONTINUE) {
 977                         seq_puts(seq, ",errors=remount-ro");
 978                 }
 979         }
 980         if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
 981                 seq_puts(seq, ",errors=continue");
 982         if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 983                 seq_puts(seq, ",errors=panic");
 984         if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 985                 seq_puts(seq, ",nouid32");
 986         if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 987                 seq_puts(seq, ",debug");
 988         if (test_opt(sb, OLDALLOC))
 989                 seq_puts(seq, ",oldalloc");
 990 #ifdef CONFIG_EXT4_FS_XATTR
 991         if (test_opt(sb, XATTR_USER) &&
 992                 !(def_mount_opts & EXT4_DEFM_XATTR_USER))
 993                 seq_puts(seq, ",user_xattr");
 994         if (!test_opt(sb, XATTR_USER) &&
 995             (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 996                 seq_puts(seq, ",nouser_xattr");
 997         }
 998 #endif
 999 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1000         if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
1001                 seq_puts(seq, ",acl");
1002         if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
1003                 seq_puts(seq, ",noacl");
1004 #endif
1005         if (sbi->s_commit_interval != JBD2_DEFAULT_MAX_COMMIT_AGE*HZ) {
1006                 seq_printf(seq, ",commit=%u",
1007                            (unsigned) (sbi->s_commit_interval / HZ));
1008         }
1009         if (sbi->s_min_batch_time != EXT4_DEF_MIN_BATCH_TIME) {
1010                 seq_printf(seq, ",min_batch_time=%u",
1011                            (unsigned) sbi->s_min_batch_time);
1012         }
1013         if (sbi->s_max_batch_time != EXT4_DEF_MAX_BATCH_TIME) {
1014                 seq_printf(seq, ",max_batch_time=%u",
1015                            (unsigned) sbi->s_min_batch_time);
1016         }
1017
1018         /*
1019          * We're changing the default of barrier mount option, so
1020          * let's always display its mount state so it's clear what its
1021          * status is.
1022          */
1023         seq_puts(seq, ",barrier=");
1024         seq_puts(seq, test_opt(sb, BARRIER) ? "1" : "0");
1025         if (test_opt(sb, JOURNAL_ASYNC_COMMIT))
1026                 seq_puts(seq, ",journal_async_commit");
1027         else if (test_opt(sb, JOURNAL_CHECKSUM))
1028                 seq_puts(seq, ",journal_checksum");
1029         if (test_opt(sb, I_VERSION))
1030                 seq_puts(seq, ",i_version");
1031         if (!test_opt(sb, DELALLOC) &&
1032             !(def_mount_opts & EXT4_DEFM_NODELALLOC))
1033                 seq_puts(seq, ",nodelalloc");
1034
1035         if (test_opt(sb, MBLK_IO_SUBMIT))
1036                 seq_puts(seq, ",mblk_io_submit");
1037         if (sbi->s_stripe)
1038                 seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
1039         /*
1040          * journal mode get enabled in different ways
1041          * So just print the value even if we didn't specify it
1042          */
1043         if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
1044                 seq_puts(seq, ",data=journal");
1045         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
1046                 seq_puts(seq, ",data=ordered");
1047         else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_WRITEBACK_DATA)
1048                 seq_puts(seq, ",data=writeback");
1049
1050         if (sbi->s_inode_readahead_blks != EXT4_DEF_INODE_READAHEAD_BLKS)
1051                 seq_printf(seq, ",inode_readahead_blks=%u",
1052                            sbi->s_inode_readahead_blks);
1053
1054         if (test_opt(sb, DATA_ERR_ABORT))
1055                 seq_puts(seq, ",data_err=abort");
1056
1057         if (test_opt(sb, NO_AUTO_DA_ALLOC))
1058                 seq_puts(seq, ",noauto_da_alloc");
1059
1060         if (test_opt(sb, DISCARD) && !(def_mount_opts & EXT4_DEFM_DISCARD))
1061                 seq_puts(seq, ",discard");
1062
1063         if (test_opt(sb, NOLOAD))
1064                 seq_puts(seq, ",norecovery");
1065
1066         if (test_opt(sb, DIOREAD_NOLOCK))
1067                 seq_puts(seq, ",dioread_nolock");
1068
1069         if (test_opt(sb, BLOCK_VALIDITY) &&
1070             !(def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY))
1071                 seq_puts(seq, ",block_validity");
1072
1073         if (!test_opt(sb, INIT_INODE_TABLE))
1074                 seq_puts(seq, ",noinit_inode_table");
1075         else if (sbi->s_li_wait_mult)
1076                 seq_printf(seq, ",init_inode_table=%u",
1077                            (unsigned) sbi->s_li_wait_mult);
1078
1079         ext4_show_quota_options(seq, sb);
1080
1081         return 0;
1082 }
1083
1084 static struct inode *ext4_nfs_get_inode(struct super_block *sb,
1085                                         u64 ino, u32 generation)
1086 {
1087         struct inode *inode;
1088
1089         if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
1090                 return ERR_PTR(-ESTALE);
1091         if (ino > le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count))
1092                 return ERR_PTR(-ESTALE);
1093
1094         /* iget isn't really right if the inode is currently unallocated!!
1095          *
1096          * ext4_read_inode will return a bad_inode if the inode had been
1097          * deleted, so we should be safe.
1098          *
1099          * Currently we don't know the generation for parent directory, so
1100          * a generation of 0 means "accept any"
1101          */
1102         inode = ext4_iget(sb, ino);
1103         if (IS_ERR(inode))
1104                 return ERR_CAST(inode);
1105         if (generation && inode->i_generation != generation) {
1106                 iput(inode);
1107                 return ERR_PTR(-ESTALE);
1108         }
1109
1110         return inode;
1111 }
1112
1113 static struct dentry *ext4_fh_to_dentry(struct super_block *sb, struct fid *fid,
1114                                         int fh_len, int fh_type)
1115 {
1116         return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
1117                                     ext4_nfs_get_inode);
1118 }
1119
1120 static struct dentry *ext4_fh_to_parent(struct super_block *sb, struct fid *fid,
1121                                         int fh_len, int fh_type)
1122 {
1123         return generic_fh_to_parent(sb, fid, fh_len, fh_type,
1124                                     ext4_nfs_get_inode);
1125 }
1126
1127 /*
1128  * Try to release metadata pages (indirect blocks, directories) which are
1129  * mapped via the block device.  Since these pages could have journal heads
1130  * which would prevent try_to_free_buffers() from freeing them, we must use
1131  * jbd2 layer's try_to_free_buffers() function to release them.
1132  */
1133 static int bdev_try_to_free_page(struct super_block *sb, struct page *page,
1134                                  gfp_t wait)
1135 {
1136         journal_t *journal = EXT4_SB(sb)->s_journal;
1137
1138         WARN_ON(PageChecked(page));
1139         if (!page_has_buffers(page))
1140                 return 0;
1141         if (journal)
1142                 return jbd2_journal_try_to_free_buffers(journal, page,
1143                                                         wait & ~__GFP_WAIT);
1144         return try_to_free_buffers(page);
1145 }
1146
1147 #ifdef CONFIG_QUOTA
1148 #define QTYPE2NAME(t) ((t) == USRQUOTA ? "user" : "group")
1149 #define QTYPE2MOPT(on, t) ((t) == USRQUOTA?((on)##USRJQUOTA):((on)##GRPJQUOTA))
1150
1151 static int ext4_write_dquot(struct dquot *dquot);
1152 static int ext4_acquire_dquot(struct dquot *dquot);
1153 static int ext4_release_dquot(struct dquot *dquot);
1154 static int ext4_mark_dquot_dirty(struct dquot *dquot);
1155 static int ext4_write_info(struct super_block *sb, int type);
1156 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
1157                                 char *path);
1158 static int ext4_quota_off(struct super_block *sb, int type);
1159 static int ext4_quota_on_mount(struct super_block *sb, int type);
1160 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
1161                                size_t len, loff_t off);
1162 static ssize_t ext4_quota_write(struct super_block *sb, int type,
1163                                 const char *data, size_t len, loff_t off);
1164
1165 static const struct dquot_operations ext4_quota_operations = {
1166 #ifdef CONFIG_QUOTA
1167         .get_reserved_space = ext4_get_reserved_space,
1168 #endif
1169         .write_dquot    = ext4_write_dquot,
1170         .acquire_dquot  = ext4_acquire_dquot,
1171         .release_dquot  = ext4_release_dquot,
1172         .mark_dirty     = ext4_mark_dquot_dirty,
1173         .write_info     = ext4_write_info,
1174         .alloc_dquot    = dquot_alloc,
1175         .destroy_dquot  = dquot_destroy,
1176 };
1177
1178 static const struct quotactl_ops ext4_qctl_operations = {
1179         .quota_on       = ext4_quota_on,
1180         .quota_off      = ext4_quota_off,
1181         .quota_sync     = dquot_quota_sync,
1182         .get_info       = dquot_get_dqinfo,
1183         .set_info       = dquot_set_dqinfo,
1184         .get_dqblk      = dquot_get_dqblk,
1185         .set_dqblk      = dquot_set_dqblk
1186 };
1187 #endif
1188
1189 static const struct super_operations ext4_sops = {
1190         .alloc_inode    = ext4_alloc_inode,
1191         .destroy_inode  = ext4_destroy_inode,
1192         .write_inode    = ext4_write_inode,
1193         .dirty_inode    = ext4_dirty_inode,
1194         .drop_inode     = ext4_drop_inode,
1195         .evict_inode    = ext4_evict_inode,
1196         .put_super      = ext4_put_super,
1197         .sync_fs        = ext4_sync_fs,
1198         .freeze_fs      = ext4_freeze,
1199         .unfreeze_fs    = ext4_unfreeze,
1200         .statfs         = ext4_statfs,
1201         .remount_fs     = ext4_remount,
1202         .show_options   = ext4_show_options,
1203 #ifdef CONFIG_QUOTA
1204         .quota_read     = ext4_quota_read,
1205         .quota_write    = ext4_quota_write,
1206 #endif
1207         .bdev_try_to_free_page = bdev_try_to_free_page,
1208 };
1209
1210 static const struct super_operations ext4_nojournal_sops = {
1211         .alloc_inode    = ext4_alloc_inode,
1212         .destroy_inode  = ext4_destroy_inode,
1213         .write_inode    = ext4_write_inode,
1214         .dirty_inode    = ext4_dirty_inode,
1215         .drop_inode     = ext4_drop_inode,
1216         .evict_inode    = ext4_evict_inode,
1217         .write_super    = ext4_write_super,
1218         .put_super      = ext4_put_super,
1219         .statfs         = ext4_statfs,
1220         .remount_fs     = ext4_remount,
1221         .show_options   = ext4_show_options,
1222 #ifdef CONFIG_QUOTA
1223         .quota_read     = ext4_quota_read,
1224         .quota_write    = ext4_quota_write,
1225 #endif
1226         .bdev_try_to_free_page = bdev_try_to_free_page,
1227 };
1228
1229 static const struct export_operations ext4_export_ops = {
1230         .fh_to_dentry = ext4_fh_to_dentry,
1231         .fh_to_parent = ext4_fh_to_parent,
1232         .get_parent = ext4_get_parent,
1233 };
1234
1235 enum {
1236         Opt_bsd_df, Opt_minix_df, Opt_grpid, Opt_nogrpid,
1237         Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro,
1238         Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov,
1239         Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
1240         Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh,
1241         Opt_commit, Opt_min_batch_time, Opt_max_batch_time,
1242         Opt_journal_update, Opt_journal_dev,
1243         Opt_journal_checksum, Opt_journal_async_commit,
1244         Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
1245         Opt_data_err_abort, Opt_data_err_ignore,
1246         Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
1247         Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_jqfmt_vfsv1, Opt_quota,
1248         Opt_noquota, Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err,
1249         Opt_resize, Opt_usrquota, Opt_grpquota, Opt_i_version,
1250         Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_mblk_io_submit,
1251         Opt_nomblk_io_submit, Opt_block_validity, Opt_noblock_validity,
1252         Opt_inode_readahead_blks, Opt_journal_ioprio,
1253         Opt_dioread_nolock, Opt_dioread_lock,
1254         Opt_discard, Opt_nodiscard,
1255         Opt_init_inode_table, Opt_noinit_inode_table,
1256 };
1257
1258 static const match_table_t tokens = {
1259         {Opt_bsd_df, "bsddf"},
1260         {Opt_minix_df, "minixdf"},
1261         {Opt_grpid, "grpid"},
1262         {Opt_grpid, "bsdgroups"},
1263         {Opt_nogrpid, "nogrpid"},
1264         {Opt_nogrpid, "sysvgroups"},
1265         {Opt_resgid, "resgid=%u"},
1266         {Opt_resuid, "resuid=%u"},
1267         {Opt_sb, "sb=%u"},
1268         {Opt_err_cont, "errors=continue"},
1269         {Opt_err_panic, "errors=panic"},
1270         {Opt_err_ro, "errors=remount-ro"},
1271         {Opt_nouid32, "nouid32"},
1272         {Opt_debug, "debug"},
1273         {Opt_oldalloc, "oldalloc"},
1274         {Opt_orlov, "orlov"},
1275         {Opt_user_xattr, "user_xattr"},
1276         {Opt_nouser_xattr, "nouser_xattr"},
1277         {Opt_acl, "acl"},
1278         {Opt_noacl, "noacl"},
1279         {Opt_noload, "noload"},
1280         {Opt_noload, "norecovery"},
1281         {Opt_nobh, "nobh"},
1282         {Opt_bh, "bh"},
1283         {Opt_commit, "commit=%u"},
1284         {Opt_min_batch_time, "min_batch_time=%u"},
1285         {Opt_max_batch_time, "max_batch_time=%u"},
1286         {Opt_journal_update, "journal=update"},
1287         {Opt_journal_dev, "journal_dev=%u"},
1288         {Opt_journal_checksum, "journal_checksum"},
1289         {Opt_journal_async_commit, "journal_async_commit"},
1290         {Opt_abort, "abort"},
1291         {Opt_data_journal, "data=journal"},
1292         {Opt_data_ordered, "data=ordered"},
1293         {Opt_data_writeback, "data=writeback"},
1294         {Opt_data_err_abort, "data_err=abort"},
1295         {Opt_data_err_ignore, "data_err=ignore"},
1296         {Opt_offusrjquota, "usrjquota="},
1297         {Opt_usrjquota, "usrjquota=%s"},
1298         {Opt_offgrpjquota, "grpjquota="},
1299         {Opt_grpjquota, "grpjquota=%s"},
1300         {Opt_jqfmt_vfsold, "jqfmt=vfsold"},
1301         {Opt_jqfmt_vfsv0, "jqfmt=vfsv0"},
1302         {Opt_jqfmt_vfsv1, "jqfmt=vfsv1"},
1303         {Opt_grpquota, "grpquota"},
1304         {Opt_noquota, "noquota"},
1305         {Opt_quota, "quota"},
1306         {Opt_usrquota, "usrquota"},
1307         {Opt_barrier, "barrier=%u"},
1308         {Opt_barrier, "barrier"},
1309         {Opt_nobarrier, "nobarrier"},
1310         {Opt_i_version, "i_version"},
1311         {Opt_stripe, "stripe=%u"},
1312         {Opt_resize, "resize"},
1313         {Opt_delalloc, "delalloc"},
1314         {Opt_nodelalloc, "nodelalloc"},
1315         {Opt_mblk_io_submit, "mblk_io_submit"},
1316         {Opt_nomblk_io_submit, "nomblk_io_submit"},
1317         {Opt_block_validity, "block_validity"},
1318         {Opt_noblock_validity, "noblock_validity"},
1319         {Opt_inode_readahead_blks, "inode_readahead_blks=%u"},
1320         {Opt_journal_ioprio, "journal_ioprio=%u"},
1321         {Opt_auto_da_alloc, "auto_da_alloc=%u"},
1322         {Opt_auto_da_alloc, "auto_da_alloc"},
1323         {Opt_noauto_da_alloc, "noauto_da_alloc"},
1324         {Opt_dioread_nolock, "dioread_nolock"},
1325         {Opt_dioread_lock, "dioread_lock"},
1326         {Opt_discard, "discard"},
1327         {Opt_nodiscard, "nodiscard"},
1328         {Opt_init_inode_table, "init_itable=%u"},
1329         {Opt_init_inode_table, "init_itable"},
1330         {Opt_noinit_inode_table, "noinit_itable"},
1331         {Opt_err, NULL},
1332 };
1333
1334 static ext4_fsblk_t get_sb_block(void **data)
1335 {
1336         ext4_fsblk_t    sb_block;
1337         char            *options = (char *) *data;
1338
1339         if (!options || strncmp(options, "sb=", 3) != 0)
1340                 return 1;       /* Default location */
1341
1342         options += 3;
1343         /* TODO: use simple_strtoll with >32bit ext4 */
1344         sb_block = simple_strtoul(options, &options, 0);
1345         if (*options && *options != ',') {
1346                 printk(KERN_ERR "EXT4-fs: Invalid sb specification: %s\n",
1347                        (char *) *data);
1348                 return 1;
1349         }
1350         if (*options == ',')
1351                 options++;
1352         *data = (void *) options;
1353
1354         return sb_block;
1355 }
1356
1357 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
1358 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
1359         "Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
1360
1361 #ifdef CONFIG_QUOTA
1362 static int set_qf_name(struct super_block *sb, int qtype, substring_t *args)
1363 {
1364         struct ext4_sb_info *sbi = EXT4_SB(sb);
1365         char *qname;
1366
1367         if (sb_any_quota_loaded(sb) &&
1368                 !sbi->s_qf_names[qtype]) {
1369                 ext4_msg(sb, KERN_ERR,
1370                         "Cannot change journaled "
1371                         "quota options when quota turned on");
1372                 return 0;
1373         }
1374         qname = match_strdup(args);
1375         if (!qname) {
1376                 ext4_msg(sb, KERN_ERR,
1377                         "Not enough memory for storing quotafile name");
1378                 return 0;
1379         }
1380         if (sbi->s_qf_names[qtype] &&
1381                 strcmp(sbi->s_qf_names[qtype], qname)) {
1382                 ext4_msg(sb, KERN_ERR,
1383                         "%s quota file already specified", QTYPE2NAME(qtype));
1384                 kfree(qname);
1385                 return 0;
1386         }
1387         sbi->s_qf_names[qtype] = qname;
1388         if (strchr(sbi->s_qf_names[qtype], '/')) {
1389                 ext4_msg(sb, KERN_ERR,
1390                         "quotafile must be on filesystem root");
1391                 kfree(sbi->s_qf_names[qtype]);
1392                 sbi->s_qf_names[qtype] = NULL;
1393                 return 0;
1394         }
1395         set_opt(sb, QUOTA);
1396         return 1;
1397 }
1398
1399 static int clear_qf_name(struct super_block *sb, int qtype)
1400 {
1401
1402         struct ext4_sb_info *sbi = EXT4_SB(sb);
1403
1404         if (sb_any_quota_loaded(sb) &&
1405                 sbi->s_qf_names[qtype]) {
1406                 ext4_msg(sb, KERN_ERR, "Cannot change journaled quota options"
1407                         " when quota turned on");
1408                 return 0;
1409         }
1410         /*
1411          * The space will be released later when all options are confirmed
1412          * to be correct
1413          */
1414         sbi->s_qf_names[qtype] = NULL;
1415         return 1;
1416 }
1417 #endif
1418
1419 static int parse_options(char *options, struct super_block *sb,
1420                          unsigned long *journal_devnum,
1421                          unsigned int *journal_ioprio,
1422                          ext4_fsblk_t *n_blocks_count, int is_remount)
1423 {
1424         struct ext4_sb_info *sbi = EXT4_SB(sb);
1425         char *p;
1426         substring_t args[MAX_OPT_ARGS];
1427         int data_opt = 0;
1428         int option;
1429 #ifdef CONFIG_QUOTA
1430         int qfmt;
1431 #endif
1432
1433         if (!options)
1434                 return 1;
1435
1436         while ((p = strsep(&options, ",")) != NULL) {
1437                 int token;
1438                 if (!*p)
1439                         continue;
1440
1441                 /*
1442                  * Initialize args struct so we know whether arg was
1443                  * found; some options take optional arguments.
1444                  */
1445                 args[0].to = args[0].from = 0;
1446                 token = match_token(p, tokens, args);
1447                 switch (token) {
1448                 case Opt_bsd_df:
1449                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1450                         clear_opt(sb, MINIX_DF);
1451                         break;
1452                 case Opt_minix_df:
1453                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1454                         set_opt(sb, MINIX_DF);
1455
1456                         break;
1457                 case Opt_grpid:
1458                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1459                         set_opt(sb, GRPID);
1460
1461                         break;
1462                 case Opt_nogrpid:
1463                         ext4_msg(sb, KERN_WARNING, deprecated_msg, p, "2.6.38");
1464                         clear_opt(sb, GRPID);
1465
1466                         break;
1467                 case Opt_resuid:
1468                         if (match_int(&args[0], &option))
1469                                 return 0;
1470                         sbi->s_resuid = option;
1471                         break;
1472                 case Opt_resgid:
1473                         if (match_int(&args[0], &option))
1474                                 return 0;
1475                         sbi->s_resgid = option;
1476                         break;
1477                 case Opt_sb:
1478                         /* handled by get_sb_block() instead of here */
1479                         /* *sb_block = match_int(&args[0]); */
1480                         break;
1481                 case Opt_err_panic:
1482                         clear_opt(sb, ERRORS_CONT);
1483                         clear_opt(sb, ERRORS_RO);
1484                         set_opt(sb, ERRORS_PANIC);
1485                         break;
1486                 case Opt_err_ro:
1487                         clear_opt(sb, ERRORS_CONT);
1488                         clear_opt(sb, ERRORS_PANIC);
1489                         set_opt(sb, ERRORS_RO);
1490                         break;
1491                 case Opt_err_cont:
1492                         clear_opt(sb, ERRORS_RO);
1493                         clear_opt(sb, ERRORS_PANIC);
1494                         set_opt(sb, ERRORS_CONT);
1495                         break;
1496                 case Opt_nouid32:
1497                         set_opt(sb, NO_UID32);
1498                         break;
1499                 case Opt_debug:
1500                         set_opt(sb, DEBUG);
1501                         break;
1502                 case Opt_oldalloc:
1503                         set_opt(sb, OLDALLOC);
1504                         break;
1505                 case Opt_orlov:
1506                         clear_opt(sb, OLDALLOC);
1507                         break;
1508 #ifdef CONFIG_EXT4_FS_XATTR
1509                 case Opt_user_xattr:
1510                         set_opt(sb, XATTR_USER);
1511                         break;
1512                 case Opt_nouser_xattr:
1513                         clear_opt(sb, XATTR_USER);
1514                         break;
1515 #else
1516                 case Opt_user_xattr:
1517                 case Opt_nouser_xattr:
1518                         ext4_msg(sb, KERN_ERR, "(no)user_xattr options not supported");
1519                         break;
1520 #endif
1521 #ifdef CONFIG_EXT4_FS_POSIX_ACL
1522                 case Opt_acl:
1523                         set_opt(sb, POSIX_ACL);
1524                         break;
1525                 case Opt_noacl:
1526                         clear_opt(sb, POSIX_ACL);
1527                         break;
1528 #else
1529                 case Opt_acl:
1530                 case Opt_noacl:
1531                         ext4_msg(sb, KERN_ERR, "(no)acl options not supported");
1532                         break;
1533 #endif
1534                 case Opt_journal_update:
1535                         /* @@@ FIXME */
1536                         /* Eventually we will want to be able to create
1537                            a journal file here.  For now, only allow the
1538                            user to specify an existing inode to be the
1539                            journal file. */
1540                         if (is_remount) {
1541                                 ext4_msg(sb, KERN_ERR,
1542                                          "Cannot specify journal on remount");
1543                                 return 0;
1544                         }
1545                         set_opt(sb, UPDATE_JOURNAL);
1546                         break;
1547                 case Opt_journal_dev:
1548                         if (is_remount) {
1549                                 ext4_msg(sb, KERN_ERR,
1550                                         "Cannot specify journal on remount");
1551                                 return 0;
1552                         }
1553                         if (match_int(&args[0], &option))
1554                                 return 0;
1555                         *journal_devnum = option;
1556                         break;
1557                 case Opt_journal_checksum:
1558                         set_opt(sb, JOURNAL_CHECKSUM);
1559                         break;
1560                 case Opt_journal_async_commit:
1561                         set_opt(sb, JOURNAL_ASYNC_COMMIT);
1562                         set_opt(sb, JOURNAL_CHECKSUM);
1563                         break;
1564                 case Opt_noload:
1565                         set_opt(sb, NOLOAD);
1566                         break;
1567                 case Opt_commit:
1568                         if (match_int(&args[0], &option))
1569                                 return 0;
1570                         if (option < 0)
1571                                 return 0;
1572                         if (option == 0)
1573                                 option = JBD2_DEFAULT_MAX_COMMIT_AGE;
1574                         sbi->s_commit_interval = HZ * option;
1575                         break;
1576                 case Opt_max_batch_time:
1577                         if (match_int(&args[0], &option))
1578                                 return 0;
1579                         if (option < 0)
1580                                 return 0;
1581                         if (option == 0)
1582                                 option = EXT4_DEF_MAX_BATCH_TIME;
1583                         sbi->s_max_batch_time = option;
1584                         break;
1585                 case Opt_min_batch_time:
1586                         if (match_int(&args[0], &option))
1587                                 return 0;
1588                         if (option < 0)
1589                                 return 0;
1590                         sbi->s_min_batch_time = option;
1591                         break;
1592                 case Opt_data_journal:
1593                         data_opt = EXT4_MOUNT_JOURNAL_DATA;
1594                         goto datacheck;
1595                 case Opt_data_ordered:
1596                         data_opt = EXT4_MOUNT_ORDERED_DATA;
1597                         goto datacheck;
1598                 case Opt_data_writeback:
1599                         data_opt = EXT4_MOUNT_WRITEBACK_DATA;
1600                 datacheck:
1601                         if (is_remount) {
1602                                 if (test_opt(sb, DATA_FLAGS) != data_opt) {
1603                                         ext4_msg(sb, KERN_ERR,
1604                                                 "Cannot change data mode on remount");
1605                                         return 0;
1606                                 }
1607                         } else {
1608                                 clear_opt(sb, DATA_FLAGS);
1609                                 sbi->s_mount_opt |= data_opt;
1610                         }
1611                         break;
1612                 case Opt_data_err_abort:
1613                         set_opt(sb, DATA_ERR_ABORT);
1614                         break;
1615                 case Opt_data_err_ignore:
1616                         clear_opt(sb, DATA_ERR_ABORT);
1617                         break;
1618 #ifdef CONFIG_QUOTA
1619                 case Opt_usrjquota:
1620                         if (!set_qf_name(sb, USRQUOTA, &args[0]))
1621                                 return 0;
1622                         break;
1623                 case Opt_grpjquota:
1624                         if (!set_qf_name(sb, GRPQUOTA, &args[0]))
1625                                 return 0;
1626                         break;
1627                 case Opt_offusrjquota:
1628                         if (!clear_qf_name(sb, USRQUOTA))
1629                                 return 0;
1630                         break;
1631                 case Opt_offgrpjquota:
1632                         if (!clear_qf_name(sb, GRPQUOTA))
1633                                 return 0;
1634                         break;
1635
1636                 case Opt_jqfmt_vfsold:
1637                         qfmt = QFMT_VFS_OLD;
1638                         goto set_qf_format;
1639                 case Opt_jqfmt_vfsv0:
1640                         qfmt = QFMT_VFS_V0;
1641                         goto set_qf_format;
1642                 case Opt_jqfmt_vfsv1:
1643                         qfmt = QFMT_VFS_V1;
1644 set_qf_format:
1645                         if (sb_any_quota_loaded(sb) &&
1646                             sbi->s_jquota_fmt != qfmt) {
1647                                 ext4_msg(sb, KERN_ERR, "Cannot change "
1648                                         "journaled quota options when "
1649                                         "quota turned on");
1650                                 return 0;
1651                         }
1652                         sbi->s_jquota_fmt = qfmt;
1653                         break;
1654                 case Opt_quota:
1655                 case Opt_usrquota:
1656                         set_opt(sb, QUOTA);
1657                         set_opt(sb, USRQUOTA);
1658                         break;
1659                 case Opt_grpquota:
1660                         set_opt(sb, QUOTA);
1661                         set_opt(sb, GRPQUOTA);
1662                         break;
1663                 case Opt_noquota:
1664                         if (sb_any_quota_loaded(sb)) {
1665                                 ext4_msg(sb, KERN_ERR, "Cannot change quota "
1666                                         "options when quota turned on");
1667                                 return 0;
1668                         }
1669                         clear_opt(sb, QUOTA);
1670                         clear_opt(sb, USRQUOTA);
1671                         clear_opt(sb, GRPQUOTA);
1672                         break;
1673 #else
1674                 case Opt_quota:
1675                 case Opt_usrquota:
1676                 case Opt_grpquota:
1677                         ext4_msg(sb, KERN_ERR,
1678                                 "quota options not supported");
1679                         break;
1680                 case Opt_usrjquota:
1681                 case Opt_grpjquota:
1682                 case Opt_offusrjquota:
1683                 case Opt_offgrpjquota:
1684                 case Opt_jqfmt_vfsold:
1685                 case Opt_jqfmt_vfsv0:
1686                 case Opt_jqfmt_vfsv1:
1687                         ext4_msg(sb, KERN_ERR,
1688                                 "journaled quota options not supported");
1689                         break;
1690                 case Opt_noquota:
1691                         break;
1692 #endif
1693                 case Opt_abort:
1694                         sbi->s_mount_flags |= EXT4_MF_FS_ABORTED;
1695                         break;
1696                 case Opt_nobarrier:
1697                         clear_opt(sb, BARRIER);
1698                         break;
1699                 case Opt_barrier:
1700                         if (args[0].from) {
1701                                 if (match_int(&args[0], &option))
1702                                         return 0;
1703                         } else
1704                                 option = 1;     /* No argument, default to 1 */
1705                         if (option)
1706                                 set_opt(sb, BARRIER);
1707                         else
1708                                 clear_opt(sb, BARRIER);
1709                         break;
1710                 case Opt_ignore:
1711                         break;
1712                 case Opt_resize:
1713                         if (!is_remount) {
1714                                 ext4_msg(sb, KERN_ERR,
1715                                         "resize option only available "
1716                                         "for remount");
1717                                 return 0;
1718                         }
1719                         if (match_int(&args[0], &option) != 0)
1720                                 return 0;
1721                         *n_blocks_count = option;
1722                         break;
1723                 case Opt_nobh:
1724                         ext4_msg(sb, KERN_WARNING,
1725                                  "Ignoring deprecated nobh option");
1726                         break;
1727                 case Opt_bh:
1728                         ext4_msg(sb, KERN_WARNING,
1729                                  "Ignoring deprecated bh option");
1730                         break;
1731                 case Opt_i_version:
1732                         set_opt(sb, I_VERSION);
1733                         sb->s_flags |= MS_I_VERSION;
1734                         break;
1735                 case Opt_nodelalloc:
1736                         clear_opt(sb, DELALLOC);
1737                         break;
1738                 case Opt_mblk_io_submit:
1739                         set_opt(sb, MBLK_IO_SUBMIT);
1740                         break;
1741                 case Opt_nomblk_io_submit:
1742                         clear_opt(sb, MBLK_IO_SUBMIT);
1743                         break;
1744                 case Opt_stripe:
1745                         if (match_int(&args[0], &option))
1746                                 return 0;
1747                         if (option < 0)
1748                                 return 0;
1749                         sbi->s_stripe = option;
1750                         break;
1751                 case Opt_delalloc:
1752                         set_opt(sb, DELALLOC);
1753                         break;
1754                 case Opt_block_validity:
1755                         set_opt(sb, BLOCK_VALIDITY);
1756                         break;
1757                 case Opt_noblock_validity:
1758                         clear_opt(sb, BLOCK_VALIDITY);
1759                         break;
1760                 case Opt_inode_readahead_blks:
1761                         if (match_int(&args[0], &option))
1762                                 return 0;
1763                         if (option < 0 || option > (1 << 30))
1764                                 return 0;
1765                         if (!is_power_of_2(option)) {
1766                                 ext4_msg(sb, KERN_ERR,
1767                                          "EXT4-fs: inode_readahead_blks"
1768                                          " must be a power of 2");
1769                                 return 0;
1770                         }
1771                         sbi->s_inode_readahead_blks = option;
1772                         break;
1773                 case Opt_journal_ioprio:
1774                         if (match_int(&args[0], &option))
1775                                 return 0;
1776                         if (option < 0 || option > 7)
1777                                 break;
1778                         *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE,
1779                                                             option);
1780                         break;
1781                 case Opt_noauto_da_alloc:
1782                         set_opt(sb, NO_AUTO_DA_ALLOC);
1783                         break;
1784                 case Opt_auto_da_alloc:
1785                         if (args[0].from) {
1786                                 if (match_int(&args[0], &option))
1787                                         return 0;
1788                         } else
1789                                 option = 1;     /* No argument, default to 1 */
1790                         if (option)
1791                                 clear_opt(sb, NO_AUTO_DA_ALLOC);
1792                         else
1793                                 set_opt(sb,NO_AUTO_DA_ALLOC);
1794                         break;
1795                 case Opt_discard:
1796                         set_opt(sb, DISCARD);
1797                         break;
1798                 case Opt_nodiscard:
1799                         clear_opt(sb, DISCARD);
1800                         break;
1801                 case Opt_dioread_nolock:
1802                         set_opt(sb, DIOREAD_NOLOCK);
1803                         break;
1804                 case Opt_dioread_lock:
1805                         clear_opt(sb, DIOREAD_NOLOCK);
1806                         break;
1807                 case Opt_init_inode_table:
1808                         set_opt(sb, INIT_INODE_TABLE);
1809                         if (args[0].from) {
1810                                 if (match_int(&args[0], &option))
1811                                         return 0;
1812                         } else
1813                                 option = EXT4_DEF_LI_WAIT_MULT;
1814                         if (option < 0)
1815                                 return 0;
1816                         sbi->s_li_wait_mult = option;
1817                         break;
1818                 case Opt_noinit_inode_table:
1819                         clear_opt(sb, INIT_INODE_TABLE);
1820                         break;
1821                 default:
1822                         ext4_msg(sb, KERN_ERR,
1823                                "Unrecognized mount option \"%s\" "
1824                                "or missing value", p);
1825                         return 0;
1826                 }
1827         }
1828 #ifdef CONFIG_QUOTA
1829         if (sbi->s_qf_names[USRQUOTA] || sbi->s_qf_names[GRPQUOTA]) {
1830                 if (test_opt(sb, USRQUOTA) && sbi->s_qf_names[USRQUOTA])
1831                         clear_opt(sb, USRQUOTA);
1832
1833                 if (test_opt(sb, GRPQUOTA) && sbi->s_qf_names[GRPQUOTA])
1834                         clear_opt(sb, GRPQUOTA);
1835
1836                 if (test_opt(sb, GRPQUOTA) || test_opt(sb, USRQUOTA)) {
1837                         ext4_msg(sb, KERN_ERR, "old and new quota "
1838                                         "format mixing");
1839                         return 0;
1840                 }
1841
1842                 if (!sbi->s_jquota_fmt) {
1843                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1844                                         "not specified");
1845                         return 0;
1846                 }
1847         } else {
1848                 if (sbi->s_jquota_fmt) {
1849                         ext4_msg(sb, KERN_ERR, "journaled quota format "
1850                                         "specified with no journaling "
1851                                         "enabled");
1852                         return 0;
1853                 }
1854         }
1855 #endif
1856         return 1;
1857 }
1858
1859 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
1860                             int read_only)
1861 {
1862         struct ext4_sb_info *sbi = EXT4_SB(sb);
1863         int res = 0;
1864
1865         if (le32_to_cpu(es->s_rev_level) > EXT4_MAX_SUPP_REV) {
1866                 ext4_msg(sb, KERN_ERR, "revision level too high, "
1867                          "forcing read-only mode");
1868                 res = MS_RDONLY;
1869         }
1870         if (read_only)
1871                 return res;
1872         if (!(sbi->s_mount_state & EXT4_VALID_FS))
1873                 ext4_msg(sb, KERN_WARNING, "warning: mounting unchecked fs, "
1874                          "running e2fsck is recommended");
1875         else if ((sbi->s_mount_state & EXT4_ERROR_FS))
1876                 ext4_msg(sb, KERN_WARNING,
1877                          "warning: mounting fs with errors, "
1878                          "running e2fsck is recommended");
1879         else if ((__s16) le16_to_cpu(es->s_max_mnt_count) >= 0 &&
1880                  le16_to_cpu(es->s_mnt_count) >=
1881                  (unsigned short) (__s16) le16_to_cpu(es->s_max_mnt_count))
1882                 ext4_msg(sb, KERN_WARNING,
1883                          "warning: maximal mount count reached, "
1884                          "running e2fsck is recommended");
1885         else if (le32_to_cpu(es->s_checkinterval) &&
1886                 (le32_to_cpu(es->s_lastcheck) +
1887                         le32_to_cpu(es->s_checkinterval) <= get_seconds()))
1888                 ext4_msg(sb, KERN_WARNING,
1889                          "warning: checktime reached, "
1890                          "running e2fsck is recommended");
1891         if (!sbi->s_journal)
1892                 es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
1893         if (!(__s16) le16_to_cpu(es->s_max_mnt_count))
1894                 es->s_max_mnt_count = cpu_to_le16(EXT4_DFL_MAX_MNT_COUNT);
1895         le16_add_cpu(&es->s_mnt_count, 1);
1896         es->s_mtime = cpu_to_le32(get_seconds());
1897         ext4_update_dynamic_rev(sb);
1898         if (sbi->s_journal)
1899                 EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
1900
1901         ext4_commit_super(sb, 1);
1902         if (test_opt(sb, DEBUG))
1903                 printk(KERN_INFO "[EXT4 FS bs=%lu, gc=%u, "
1904                                 "bpg=%lu, ipg=%lu, mo=%04x, mo2=%04x]\n",
1905                         sb->s_blocksize,
1906                         sbi->s_groups_count,
1907                         EXT4_BLOCKS_PER_GROUP(sb),
1908                         EXT4_INODES_PER_GROUP(sb),
1909                         sbi->s_mount_opt, sbi->s_mount_opt2);
1910
1911         return res;
1912 }
1913
1914 static int ext4_fill_flex_info(struct super_block *sb)
1915 {
1916         struct ext4_sb_info *sbi = EXT4_SB(sb);
1917         struct ext4_group_desc *gdp = NULL;
1918         ext4_group_t flex_group_count;
1919         ext4_group_t flex_group;
1920         int groups_per_flex = 0;
1921         size_t size;
1922         int i;
1923
1924         sbi->s_log_groups_per_flex = sbi->s_es->s_log_groups_per_flex;
1925         groups_per_flex = 1 << sbi->s_log_groups_per_flex;
1926
1927         if (groups_per_flex < 2) {
1928                 sbi->s_log_groups_per_flex = 0;
1929                 return 1;
1930         }
1931
1932         /* We allocate both existing and potentially added groups */
1933         flex_group_count = ((sbi->s_groups_count + groups_per_flex - 1) +
1934                         ((le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks) + 1) <<
1935                               EXT4_DESC_PER_BLOCK_BITS(sb))) / groups_per_flex;
1936         size = flex_group_count * sizeof(struct flex_groups);
1937         sbi->s_flex_groups = kzalloc(size, GFP_KERNEL);
1938         if (sbi->s_flex_groups == NULL) {
1939                 sbi->s_flex_groups = vzalloc(size);
1940                 if (sbi->s_flex_groups == NULL) {
1941                         ext4_msg(sb, KERN_ERR,
1942                                  "not enough memory for %u flex groups",
1943                                  flex_group_count);
1944                         goto failed;
1945                 }
1946         }
1947
1948         for (i = 0; i < sbi->s_groups_count; i++) {
1949                 gdp = ext4_get_group_desc(sb, i, NULL);
1950
1951                 flex_group = ext4_flex_group(sbi, i);
1952                 atomic_add(ext4_free_inodes_count(sb, gdp),
1953                            &sbi->s_flex_groups[flex_group].free_inodes);
1954                 atomic_add(ext4_free_blks_count(sb, gdp),
1955                            &sbi->s_flex_groups[flex_group].free_blocks);
1956                 atomic_add(ext4_used_dirs_count(sb, gdp),
1957                            &sbi->s_flex_groups[flex_group].used_dirs);
1958         }
1959
1960         return 1;
1961 failed:
1962         return 0;
1963 }
1964
1965 __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 block_group,
1966                             struct ext4_group_desc *gdp)
1967 {
1968         __u16 crc = 0;
1969
1970         if (sbi->s_es->s_feature_ro_compat &
1971             cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) {
1972                 int offset = offsetof(struct ext4_group_desc, bg_checksum);
1973                 __le32 le_group = cpu_to_le32(block_group);
1974
1975                 crc = crc16(~0, sbi->s_es->s_uuid, sizeof(sbi->s_es->s_uuid));
1976                 crc = crc16(crc, (__u8 *)&le_group, sizeof(le_group));
1977                 crc = crc16(crc, (__u8 *)gdp, offset);
1978                 offset += sizeof(gdp->bg_checksum); /* skip checksum */
1979                 /* for checksum of struct ext4_group_desc do the rest...*/
1980                 if ((sbi->s_es->s_feature_incompat &
1981                      cpu_to_le32(EXT4_FEATURE_INCOMPAT_64BIT)) &&
1982                     offset < le16_to_cpu(sbi->s_es->s_desc_size))
1983                         crc = crc16(crc, (__u8 *)gdp + offset,
1984                                     le16_to_cpu(sbi->s_es->s_desc_size) -
1985                                         offset);
1986         }
1987
1988         return cpu_to_le16(crc);
1989 }
1990
1991 int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 block_group,
1992                                 struct ext4_group_desc *gdp)
1993 {
1994         if ((sbi->s_es->s_feature_ro_compat &
1995              cpu_to_le32(EXT4_FEATURE_RO_COMPAT_GDT_CSUM)) &&
1996             (gdp->bg_checksum != ext4_group_desc_csum(sbi, block_group, gdp)))
1997                 return 0;
1998
1999         return 1;
2000 }
2001
2002 /* Called at mount-time, super-block is locked */
2003 static int ext4_check_descriptors(struct super_block *sb,
2004                                   ext4_group_t *first_not_zeroed)
2005 {
2006         struct ext4_sb_info *sbi = EXT4_SB(sb);
2007         ext4_fsblk_t first_block = le32_to_cpu(sbi->s_es->s_first_data_block);
2008         ext4_fsblk_t last_block;
2009         ext4_fsblk_t block_bitmap;
2010         ext4_fsblk_t inode_bitmap;
2011         ext4_fsblk_t inode_table;
2012         int flexbg_flag = 0;
2013         ext4_group_t i, grp = sbi->s_groups_count;
2014
2015         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
2016                 flexbg_flag = 1;
2017
2018         ext4_debug("Checking group descriptors");
2019
2020         for (i = 0; i < sbi->s_groups_count; i++) {
2021                 struct ext4_group_desc *gdp = ext4_get_group_desc(sb, i, NULL);
2022
2023                 if (i == sbi->s_groups_count - 1 || flexbg_flag)
2024                         last_block = ext4_blocks_count(sbi->s_es) - 1;
2025                 else
2026                         last_block = first_block +
2027                                 (EXT4_BLOCKS_PER_GROUP(sb) - 1);
2028
2029                 if ((grp == sbi->s_groups_count) &&
2030                    !(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2031                         grp = i;
2032
2033                 block_bitmap = ext4_block_bitmap(sb, gdp);
2034                 if (block_bitmap < first_block || block_bitmap > last_block) {
2035                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2036                                "Block bitmap for group %u not in group "
2037                                "(block %llu)!", i, block_bitmap);
2038                         return 0;
2039                 }
2040                 inode_bitmap = ext4_inode_bitmap(sb, gdp);
2041                 if (inode_bitmap < first_block || inode_bitmap > last_block) {
2042                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2043                                "Inode bitmap for group %u not in group "
2044                                "(block %llu)!", i, inode_bitmap);
2045                         return 0;
2046                 }
2047                 inode_table = ext4_inode_table(sb, gdp);
2048                 if (inode_table < first_block ||
2049                     inode_table + sbi->s_itb_per_group - 1 > last_block) {
2050                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2051                                "Inode table for group %u not in group "
2052                                "(block %llu)!", i, inode_table);
2053                         return 0;
2054                 }
2055                 ext4_lock_group(sb, i);
2056                 if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
2057                         ext4_msg(sb, KERN_ERR, "ext4_check_descriptors: "
2058                                  "Checksum for group %u failed (%u!=%u)",
2059                                  i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
2060                                      gdp)), le16_to_cpu(gdp->bg_checksum));
2061                         if (!(sb->s_flags & MS_RDONLY)) {
2062                                 ext4_unlock_group(sb, i);
2063                                 return 0;
2064                         }
2065                 }
2066                 ext4_unlock_group(sb, i);
2067                 if (!flexbg_flag)
2068                         first_block += EXT4_BLOCKS_PER_GROUP(sb);
2069         }
2070         if (NULL != first_not_zeroed)
2071                 *first_not_zeroed = grp;
2072
2073         ext4_free_blocks_count_set(sbi->s_es, ext4_count_free_blocks(sb));
2074         sbi->s_es->s_free_inodes_count =cpu_to_le32(ext4_count_free_inodes(sb));
2075         return 1;
2076 }
2077
2078 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
2079  * the superblock) which were deleted from all directories, but held open by
2080  * a process at the time of a crash.  We walk the list and try to delete these
2081  * inodes at recovery time (only with a read-write filesystem).
2082  *
2083  * In order to keep the orphan inode chain consistent during traversal (in
2084  * case of crash during recovery), we link each inode into the superblock
2085  * orphan list_head and handle it the same way as an inode deletion during
2086  * normal operation (which journals the operations for us).
2087  *
2088  * We only do an iget() and an iput() on each inode, which is very safe if we
2089  * accidentally point at an in-use or already deleted inode.  The worst that
2090  * can happen in this case is that we get a "bit already cleared" message from
2091  * ext4_free_inode().  The only reason we would point at a wrong inode is if
2092  * e2fsck was run on this filesystem, and it must have already done the orphan
2093  * inode cleanup for us, so we can safely abort without any further action.
2094  */
2095 static void ext4_orphan_cleanup(struct super_block *sb,
2096                                 struct ext4_super_block *es)
2097 {
2098         unsigned int s_flags = sb->s_flags;
2099         int nr_orphans = 0, nr_truncates = 0;
2100 #ifdef CONFIG_QUOTA
2101         int i;
2102 #endif
2103         if (!es->s_last_orphan) {
2104                 jbd_debug(4, "no orphan inodes to clean up\n");
2105                 return;
2106         }
2107
2108         if (bdev_read_only(sb->s_bdev)) {
2109                 ext4_msg(sb, KERN_ERR, "write access "
2110                         "unavailable, skipping orphan cleanup");
2111                 return;
2112         }
2113
2114         if (EXT4_SB(sb)->s_mount_state & EXT4_ERROR_FS) {
2115                 if (es->s_last_orphan)
2116                         jbd_debug(1, "Errors on filesystem, "
2117                                   "clearing orphan list.\n");
2118                 es->s_last_orphan = 0;
2119                 jbd_debug(1, "Skipping orphan recovery on fs with errors.\n");
2120                 return;
2121         }
2122
2123         if (s_flags & MS_RDONLY) {
2124                 ext4_msg(sb, KERN_INFO, "orphan cleanup on readonly fs");
2125                 sb->s_flags &= ~MS_RDONLY;
2126         }
2127 #ifdef CONFIG_QUOTA
2128         /* Needed for iput() to work correctly and not trash data */
2129         sb->s_flags |= MS_ACTIVE;
2130         /* Turn on quotas so that they are updated correctly */
2131         for (i = 0; i < MAXQUOTAS; i++) {
2132                 if (EXT4_SB(sb)->s_qf_names[i]) {
2133                         int ret = ext4_quota_on_mount(sb, i);
2134                         if (ret < 0)
2135                                 ext4_msg(sb, KERN_ERR,
2136                                         "Cannot turn on journaled "
2137                                         "quota: error %d", ret);
2138                 }
2139         }
2140 #endif
2141
2142         while (es->s_last_orphan) {
2143                 struct inode *inode;
2144
2145                 inode = ext4_orphan_get(sb, le32_to_cpu(es->s_last_orphan));
2146                 if (IS_ERR(inode)) {
2147                         es->s_last_orphan = 0;
2148                         break;
2149                 }
2150
2151                 list_add(&EXT4_I(inode)->i_orphan, &EXT4_SB(sb)->s_orphan);
2152                 dquot_initialize(inode);
2153                 if (inode->i_nlink) {
2154                         ext4_msg(sb, KERN_DEBUG,
2155                                 "%s: truncating inode %lu to %lld bytes",
2156                                 __func__, inode->i_ino, inode->i_size);
2157                         jbd_debug(2, "truncating inode %lu to %lld bytes\n",
2158                                   inode->i_ino, inode->i_size);
2159                         ext4_truncate(inode);
2160                         nr_truncates++;
2161                 } else {
2162                         ext4_msg(sb, KERN_DEBUG,
2163                                 "%s: deleting unreferenced inode %lu",
2164                                 __func__, inode->i_ino);
2165                         jbd_debug(2, "deleting unreferenced inode %lu\n",
2166                                   inode->i_ino);
2167                         nr_orphans++;
2168                 }
2169                 iput(inode);  /* The delete magic happens here! */
2170         }
2171
2172 #define PLURAL(x) (x), ((x) == 1) ? "" : "s"
2173
2174         if (nr_orphans)
2175                 ext4_msg(sb, KERN_INFO, "%d orphan inode%s deleted",
2176                        PLURAL(nr_orphans));
2177         if (nr_truncates)
2178                 ext4_msg(sb, KERN_INFO, "%d truncate%s cleaned up",
2179                        PLURAL(nr_truncates));
2180 #ifdef CONFIG_QUOTA
2181         /* Turn quotas off */
2182         for (i = 0; i < MAXQUOTAS; i++) {
2183                 if (sb_dqopt(sb)->files[i])
2184                         dquot_quota_off(sb, i);
2185         }
2186 #endif
2187         sb->s_flags = s_flags; /* Restore MS_RDONLY status */
2188 }
2189
2190 /*
2191  * Maximal extent format file size.
2192  * Resulting logical blkno at s_maxbytes must fit in our on-disk
2193  * extent format containers, within a sector_t, and within i_blocks
2194  * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
2195  * so that won't be a limiting factor.
2196  *
2197  * Note, this does *not* consider any metadata overhead for vfs i_blocks.
2198  */
2199 static loff_t ext4_max_size(int blkbits, int has_huge_files)
2200 {
2201         loff_t res;
2202         loff_t upper_limit = MAX_LFS_FILESIZE;
2203
2204         /* small i_blocks in vfs inode? */
2205         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2206                 /*
2207                  * CONFIG_LBDAF is not enabled implies the inode
2208                  * i_block represent total blocks in 512 bytes
2209                  * 32 == size of vfs inode i_blocks * 8
2210                  */
2211                 upper_limit = (1LL << 32) - 1;
2212
2213                 /* total blocks in file system block size */
2214                 upper_limit >>= (blkbits - 9);
2215                 upper_limit <<= blkbits;
2216         }
2217
2218         /* 32-bit extent-start container, ee_block */
2219         res = 1LL << 32;
2220         res <<= blkbits;
2221         res -= 1;
2222
2223         /* Sanity check against vm- & vfs- imposed limits */
2224         if (res > upper_limit)
2225                 res = upper_limit;
2226
2227         return res;
2228 }
2229
2230 /*
2231  * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
2232  * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
2233  * We need to be 1 filesystem block less than the 2^48 sector limit.
2234  */
2235 static loff_t ext4_max_bitmap_size(int bits, int has_huge_files)
2236 {
2237         loff_t res = EXT4_NDIR_BLOCKS;
2238         int meta_blocks;
2239         loff_t upper_limit;
2240         /* This is calculated to be the largest file size for a dense, block
2241          * mapped file such that the file's total number of 512-byte sectors,
2242          * including data and all indirect blocks, does not exceed (2^48 - 1).
2243          *
2244          * __u32 i_blocks_lo and _u16 i_blocks_high represent the total
2245          * number of 512-byte sectors of the file.
2246          */
2247
2248         if (!has_huge_files || sizeof(blkcnt_t) < sizeof(u64)) {
2249                 /*
2250                  * !has_huge_files or CONFIG_LBDAF not enabled implies that
2251                  * the inode i_block field represents total file blocks in
2252                  * 2^32 512-byte sectors == size of vfs inode i_blocks * 8
2253                  */
2254                 upper_limit = (1LL << 32) - 1;
2255
2256                 /* total blocks in file system block size */
2257                 upper_limit >>= (bits - 9);
2258
2259         } else {
2260                 /*
2261                  * We use 48 bit ext4_inode i_blocks
2262                  * With EXT4_HUGE_FILE_FL set the i_blocks
2263                  * represent total number of blocks in
2264                  * file system block size
2265                  */
2266                 upper_limit = (1LL << 48) - 1;
2267
2268         }
2269
2270         /* indirect blocks */
2271         meta_blocks = 1;
2272         /* double indirect blocks */
2273         meta_blocks += 1 + (1LL << (bits-2));
2274         /* tripple indirect blocks */
2275         meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
2276
2277         upper_limit -= meta_blocks;
2278         upper_limit <<= bits;
2279
2280         res += 1LL << (bits-2);
2281         res += 1LL << (2*(bits-2));
2282         res += 1LL << (3*(bits-2));
2283         res <<= bits;
2284         if (res > upper_limit)
2285                 res = upper_limit;
2286
2287         if (res > MAX_LFS_FILESIZE)
2288                 res = MAX_LFS_FILESIZE;
2289
2290         return res;
2291 }
2292
2293 static ext4_fsblk_t descriptor_loc(struct super_block *sb,
2294                                    ext4_fsblk_t logical_sb_block, int nr)
2295 {
2296         struct ext4_sb_info *sbi = EXT4_SB(sb);
2297         ext4_group_t bg, first_meta_bg;
2298         int has_super = 0;
2299
2300         first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
2301
2302         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) ||
2303             nr < first_meta_bg)
2304                 return logical_sb_block + nr + 1;
2305         bg = sbi->s_desc_per_block * nr;
2306         if (ext4_bg_has_super(sb, bg))
2307                 has_super = 1;
2308
2309         return (has_super + ext4_group_first_block_no(sb, bg));
2310 }
2311
2312 /**
2313  * ext4_get_stripe_size: Get the stripe size.
2314  * @sbi: In memory super block info
2315  *
2316  * If we have specified it via mount option, then
2317  * use the mount option value. If the value specified at mount time is
2318  * greater than the blocks per group use the super block value.
2319  * If the super block value is greater than blocks per group return 0.
2320  * Allocator needs it be less than blocks per group.
2321  *
2322  */
2323 static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
2324 {
2325         unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
2326         unsigned long stripe_width =
2327                         le32_to_cpu(sbi->s_es->s_raid_stripe_width);
2328
2329         if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
2330                 return sbi->s_stripe;
2331
2332         if (stripe_width <= sbi->s_blocks_per_group)
2333                 return stripe_width;
2334
2335         if (stride <= sbi->s_blocks_per_group)
2336                 return stride;
2337
2338         return 0;
2339 }
2340
2341 /* sysfs supprt */
2342
2343 struct ext4_attr {
2344         struct attribute attr;
2345         ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
2346         ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
2347                          const char *, size_t);
2348         int offset;
2349 };
2350
2351 static int parse_strtoul(const char *buf,
2352                 unsigned long max, unsigned long *value)
2353 {
2354         char *endp;
2355
2356         *value = simple_strtoul(skip_spaces(buf), &endp, 0);
2357         endp = skip_spaces(endp);
2358         if (*endp || *value > max)
2359                 return -EINVAL;
2360
2361         return 0;
2362 }
2363
2364 static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
2365                                               struct ext4_sb_info *sbi,
2366                                               char *buf)
2367 {
2368         return snprintf(buf, PAGE_SIZE, "%llu\n",
2369                         (s64) percpu_counter_sum(&sbi->s_dirtyblocks_counter));
2370 }
2371
2372 static ssize_t session_write_kbytes_show(struct ext4_attr *a,
2373                                          struct ext4_sb_info *sbi, char *buf)
2374 {
2375         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2376
2377         if (!sb->s_bdev->bd_part)
2378                 return snprintf(buf, PAGE_SIZE, "0\n");
2379         return snprintf(buf, PAGE_SIZE, "%lu\n",
2380                         (part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2381                          sbi->s_sectors_written_start) >> 1);
2382 }
2383
2384 static ssize_t lifetime_write_kbytes_show(struct ext4_attr *a,
2385                                           struct ext4_sb_info *sbi, char *buf)
2386 {
2387         struct super_block *sb = sbi->s_buddy_cache->i_sb;
2388
2389         if (!sb->s_bdev->bd_part)
2390                 return snprintf(buf, PAGE_SIZE, "0\n");
2391         return snprintf(buf, PAGE_SIZE, "%llu\n",
2392                         (unsigned long long)(sbi->s_kbytes_written +
2393                         ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
2394                           EXT4_SB(sb)->s_sectors_written_start) >> 1)));
2395 }
2396
2397 static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
2398                                           struct ext4_sb_info *sbi,
2399                                           const char *buf, size_t count)
2400 {
2401         unsigned long t;
2402
2403         if (parse_strtoul(buf, 0x40000000, &t))
2404                 return -EINVAL;
2405
2406         if (!is_power_of_2(t))
2407                 return -EINVAL;
2408
2409         sbi->s_inode_readahead_blks = t;
2410         return count;
2411 }
2412
2413 static ssize_t sbi_ui_show(struct ext4_attr *a,
2414                            struct ext4_sb_info *sbi, char *buf)
2415 {
2416         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2417
2418         return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
2419 }
2420
2421 static ssize_t sbi_ui_store(struct ext4_attr *a,
2422                             struct ext4_sb_info *sbi,
2423                             const char *buf, size_t count)
2424 {
2425         unsigned int *ui = (unsigned int *) (((char *) sbi) + a->offset);
2426         unsigned long t;
2427
2428         if (parse_strtoul(buf, 0xffffffff, &t))
2429                 return -EINVAL;
2430         *ui = t;
2431         return count;
2432 }
2433
2434 #define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
2435 static struct ext4_attr ext4_attr_##_name = {                   \
2436         .attr = {.name = __stringify(_name), .mode = _mode },   \
2437         .show   = _show,                                        \
2438         .store  = _store,                                       \
2439         .offset = offsetof(struct ext4_sb_info, _elname),       \
2440 }
2441 #define EXT4_ATTR(name, mode, show, store) \
2442 static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
2443
2444 #define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
2445 #define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
2446 #define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
2447 #define EXT4_RW_ATTR_SBI_UI(name, elname)       \
2448         EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
2449 #define ATTR_LIST(name) &ext4_attr_##name.attr
2450
2451 EXT4_RO_ATTR(delayed_allocation_blocks);
2452 EXT4_RO_ATTR(session_write_kbytes);
2453 EXT4_RO_ATTR(lifetime_write_kbytes);
2454 EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
2455                  inode_readahead_blks_store, s_inode_readahead_blks);
2456 EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
2457 EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
2458 EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
2459 EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
2460 EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
2461 EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
2462 EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
2463 EXT4_RW_ATTR_SBI_UI(max_writeback_mb_bump, s_max_writeback_mb_bump);
2464
2465 static struct attribute *ext4_attrs[] = {
2466         ATTR_LIST(delayed_allocation_blocks),
2467         ATTR_LIST(session_write_kbytes),
2468         ATTR_LIST(lifetime_write_kbytes),
2469         ATTR_LIST(inode_readahead_blks),
2470         ATTR_LIST(inode_goal),
2471         ATTR_LIST(mb_stats),
2472         ATTR_LIST(mb_max_to_scan),
2473         ATTR_LIST(mb_min_to_scan),
2474         ATTR_LIST(mb_order2_req),
2475         ATTR_LIST(mb_stream_req),
2476         ATTR_LIST(mb_group_prealloc),
2477         ATTR_LIST(max_writeback_mb_bump),
2478         NULL,
2479 };
2480
2481 /* Features this copy of ext4 supports */
2482 EXT4_INFO_ATTR(lazy_itable_init);
2483 EXT4_INFO_ATTR(batched_discard);
2484
2485 static struct attribute *ext4_feat_attrs[] = {
2486         ATTR_LIST(lazy_itable_init),
2487         ATTR_LIST(batched_discard),
2488         NULL,
2489 };
2490
2491 static ssize_t ext4_attr_show(struct kobject *kobj,
2492                               struct attribute *attr, char *buf)
2493 {
2494         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2495                                                 s_kobj);
2496         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2497
2498         return a->show ? a->show(a, sbi, buf) : 0;
2499 }
2500
2501 static ssize_t ext4_attr_store(struct kobject *kobj,
2502                                struct attribute *attr,
2503                                const char *buf, size_t len)
2504 {
2505         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2506                                                 s_kobj);
2507         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
2508
2509         return a->store ? a->store(a, sbi, buf, len) : 0;
2510 }
2511
2512 static void ext4_sb_release(struct kobject *kobj)
2513 {
2514         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
2515                                                 s_kobj);
2516         complete(&sbi->s_kobj_unregister);
2517 }
2518
2519 static const struct sysfs_ops ext4_attr_ops = {
2520         .show   = ext4_attr_show,
2521         .store  = ext4_attr_store,
2522 };
2523
2524 static struct kobj_type ext4_ktype = {
2525         .default_attrs  = ext4_attrs,
2526         .sysfs_ops      = &ext4_attr_ops,
2527         .release        = ext4_sb_release,
2528 };
2529
2530 static void ext4_feat_release(struct kobject *kobj)
2531 {
2532         complete(&ext4_feat->f_kobj_unregister);
2533 }
2534
2535 static struct kobj_type ext4_feat_ktype = {
2536         .default_attrs  = ext4_feat_attrs,
2537         .sysfs_ops      = &ext4_attr_ops,
2538         .release        = ext4_feat_release,
2539 };
2540
2541 /*
2542  * Check whether this filesystem can be mounted based on
2543  * the features present and the RDONLY/RDWR mount requested.
2544  * Returns 1 if this filesystem can be mounted as requested,
2545  * 0 if it cannot be.
2546  */
2547 static int ext4_feature_set_ok(struct super_block *sb, int readonly)
2548 {
2549         if (EXT4_HAS_INCOMPAT_FEATURE(sb, ~EXT4_FEATURE_INCOMPAT_SUPP)) {
2550                 ext4_msg(sb, KERN_ERR,
2551                         "Couldn't mount because of "
2552                         "unsupported optional features (%x)",
2553                         (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_incompat) &
2554                         ~EXT4_FEATURE_INCOMPAT_SUPP));
2555                 return 0;
2556         }
2557
2558         if (readonly)
2559                 return 1;
2560
2561         /* Check that feature set is OK for a read-write mount */
2562         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, ~EXT4_FEATURE_RO_COMPAT_SUPP)) {
2563                 ext4_msg(sb, KERN_ERR, "couldn't mount RDWR because of "
2564                          "unsupported optional features (%x)",
2565                          (le32_to_cpu(EXT4_SB(sb)->s_es->s_feature_ro_compat) &
2566                                 ~EXT4_FEATURE_RO_COMPAT_SUPP));
2567                 return 0;
2568         }
2569         /*
2570          * Large file size enabled file system can only be mounted
2571          * read-write on 32-bit systems if kernel is built with CONFIG_LBDAF
2572          */
2573         if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
2574                 if (sizeof(blkcnt_t) < sizeof(u64)) {
2575                         ext4_msg(sb, KERN_ERR, "Filesystem with huge files "
2576                                  "cannot be mounted RDWR without "
2577                                  "CONFIG_LBDAF");
2578                         return 0;
2579                 }
2580         }
2581         return 1;
2582 }
2583
2584 /*
2585  * This function is called once a day if we have errors logged
2586  * on the file system
2587  */
2588 static void print_daily_error_info(unsigned long arg)
2589 {
2590         struct super_block *sb = (struct super_block *) arg;
2591         struct ext4_sb_info *sbi;
2592         struct ext4_super_block *es;
2593
2594         sbi = EXT4_SB(sb);
2595         es = sbi->s_es;
2596
2597         if (es->s_error_count)
2598                 ext4_msg(sb, KERN_NOTICE, "error count: %u",
2599                          le32_to_cpu(es->s_error_count));
2600         if (es->s_first_error_time) {
2601                 printk(KERN_NOTICE "EXT4-fs (%s): initial error at %u: %.*s:%d",
2602                        sb->s_id, le32_to_cpu(es->s_first_error_time),
2603                        (int) sizeof(es->s_first_error_func),
2604                        es->s_first_error_func,
2605                        le32_to_cpu(es->s_first_error_line));
2606                 if (es->s_first_error_ino)
2607                         printk(": inode %u",
2608                                le32_to_cpu(es->s_first_error_ino));
2609                 if (es->s_first_error_block)
2610                         printk(": block %llu", (unsigned long long)
2611                                le64_to_cpu(es->s_first_error_block));
2612                 printk("\n");
2613         }
2614         if (es->s_last_error_time) {
2615                 printk(KERN_NOTICE "EXT4-fs (%s): last error at %u: %.*s:%d",
2616                        sb->s_id, le32_to_cpu(es->s_last_error_time),
2617                        (int) sizeof(es->s_last_error_func),
2618                        es->s_last_error_func,
2619                        le32_to_cpu(es->s_last_error_line));
2620                 if (es->s_last_error_ino)
2621                         printk(": inode %u",
2622                                le32_to_cpu(es->s_last_error_ino));
2623                 if (es->s_last_error_block)
2624                         printk(": block %llu", (unsigned long long)
2625                                le64_to_cpu(es->s_last_error_block));
2626                 printk("\n");
2627         }
2628         mod_timer(&sbi->s_err_report, jiffies + 24*60*60*HZ);  /* Once a day */
2629 }
2630
2631 static void ext4_lazyinode_timeout(unsigned long data)
2632 {
2633         struct task_struct *p = (struct task_struct *)data;
2634         wake_up_process(p);
2635 }
2636
2637 /* Find next suitable group and run ext4_init_inode_table */
2638 static int ext4_run_li_request(struct ext4_li_request *elr)
2639 {
2640         struct ext4_group_desc *gdp = NULL;
2641         ext4_group_t group, ngroups;
2642         struct super_block *sb;
2643         unsigned long timeout = 0;
2644         int ret = 0;
2645
2646         sb = elr->lr_super;
2647         ngroups = EXT4_SB(sb)->s_groups_count;
2648
2649         for (group = elr->lr_next_group; group < ngroups; group++) {
2650                 gdp = ext4_get_group_desc(sb, group, NULL);
2651                 if (!gdp) {
2652                         ret = 1;
2653                         break;
2654                 }
2655
2656                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2657                         break;
2658         }
2659
2660         if (group == ngroups)
2661                 ret = 1;
2662
2663         if (!ret) {
2664                 timeout = jiffies;
2665                 ret = ext4_init_inode_table(sb, group,
2666                                             elr->lr_timeout ? 0 : 1);
2667                 if (elr->lr_timeout == 0) {
2668                         timeout = jiffies - timeout;
2669                         if (elr->lr_sbi->s_li_wait_mult)
2670                                 timeout *= elr->lr_sbi->s_li_wait_mult;
2671                         else
2672                                 timeout *= 20;
2673                         elr->lr_timeout = timeout;
2674                 }
2675                 elr->lr_next_sched = jiffies + elr->lr_timeout;
2676                 elr->lr_next_group = group + 1;
2677         }
2678
2679         return ret;
2680 }
2681
2682 /*
2683  * Remove lr_request from the list_request and free the
2684  * request tructure. Should be called with li_list_mtx held
2685  */
2686 static void ext4_remove_li_request(struct ext4_li_request *elr)
2687 {
2688         struct ext4_sb_info *sbi;
2689
2690         if (!elr)
2691                 return;
2692
2693         sbi = elr->lr_sbi;
2694
2695         list_del(&elr->lr_request);
2696         sbi->s_li_request = NULL;
2697         kfree(elr);
2698 }
2699
2700 static void ext4_unregister_li_request(struct super_block *sb)
2701 {
2702         struct ext4_li_request *elr = EXT4_SB(sb)->s_li_request;
2703
2704         if (!ext4_li_info)
2705                 return;
2706
2707         mutex_lock(&ext4_li_info->li_list_mtx);
2708         ext4_remove_li_request(elr);
2709         mutex_unlock(&ext4_li_info->li_list_mtx);
2710 }
2711
2712 /*
2713  * This is the function where ext4lazyinit thread lives. It walks
2714  * through the request list searching for next scheduled filesystem.
2715  * When such a fs is found, run the lazy initialization request
2716  * (ext4_rn_li_request) and keep track of the time spend in this
2717  * function. Based on that time we compute next schedule time of
2718  * the request. When walking through the list is complete, compute
2719  * next waking time and put itself into sleep.
2720  */
2721 static int ext4_lazyinit_thread(void *arg)
2722 {
2723         struct ext4_lazy_init *eli = (struct ext4_lazy_init *)arg;
2724         struct list_head *pos, *n;
2725         struct ext4_li_request *elr;
2726         unsigned long next_wakeup;
2727         DEFINE_WAIT(wait);
2728
2729         BUG_ON(NULL == eli);
2730
2731         eli->li_timer.data = (unsigned long)current;
2732         eli->li_timer.function = ext4_lazyinode_timeout;
2733
2734         eli->li_task = current;
2735         wake_up(&eli->li_wait_task);
2736
2737 cont_thread:
2738         while (true) {
2739                 next_wakeup = MAX_JIFFY_OFFSET;
2740
2741                 mutex_lock(&eli->li_list_mtx);
2742                 if (list_empty(&eli->li_request_list)) {
2743                         mutex_unlock(&eli->li_list_mtx);
2744                         goto exit_thread;
2745                 }
2746
2747                 list_for_each_safe(pos, n, &eli->li_request_list) {
2748                         elr = list_entry(pos, struct ext4_li_request,
2749                                          lr_request);
2750
2751                         if (time_after_eq(jiffies, elr->lr_next_sched)) {
2752                                 if (ext4_run_li_request(elr) != 0) {
2753                                         /* error, remove the lazy_init job */
2754                                         ext4_remove_li_request(elr);
2755                                         continue;
2756                                 }
2757                         }
2758
2759                         if (time_before(elr->lr_next_sched, next_wakeup))
2760                                 next_wakeup = elr->lr_next_sched;
2761                 }
2762                 mutex_unlock(&eli->li_list_mtx);
2763
2764                 if (freezing(current))
2765                         refrigerator();
2766
2767                 if ((time_after_eq(jiffies, next_wakeup)) ||
2768                     (MAX_JIFFY_OFFSET == next_wakeup)) {
2769                         cond_resched();
2770                         continue;
2771                 }
2772
2773                 eli->li_timer.expires = next_wakeup;
2774                 add_timer(&eli->li_timer);
2775                 prepare_to_wait(&eli->li_wait_daemon, &wait,
2776                                 TASK_INTERRUPTIBLE);
2777                 if (time_before(jiffies, next_wakeup))
2778                         schedule();
2779                 finish_wait(&eli->li_wait_daemon, &wait);
2780         }
2781
2782 exit_thread:
2783         /*
2784          * It looks like the request list is empty, but we need
2785          * to check it under the li_list_mtx lock, to prevent any
2786          * additions into it, and of course we should lock ext4_li_mtx
2787          * to atomically free the list and ext4_li_info, because at
2788          * this point another ext4 filesystem could be registering
2789          * new one.
2790          */
2791         mutex_lock(&ext4_li_mtx);
2792         mutex_lock(&eli->li_list_mtx);
2793         if (!list_empty(&eli->li_request_list)) {
2794                 mutex_unlock(&eli->li_list_mtx);
2795                 mutex_unlock(&ext4_li_mtx);
2796                 goto cont_thread;
2797         }
2798         mutex_unlock(&eli->li_list_mtx);
2799         del_timer_sync(&ext4_li_info->li_timer);
2800         eli->li_task = NULL;
2801         wake_up(&eli->li_wait_task);
2802
2803         kfree(ext4_li_info);
2804         ext4_li_info = NULL;
2805         mutex_unlock(&ext4_li_mtx);
2806
2807         return 0;
2808 }
2809
2810 static void ext4_clear_request_list(void)
2811 {
2812         struct list_head *pos, *n;
2813         struct ext4_li_request *elr;
2814
2815         mutex_lock(&ext4_li_info->li_list_mtx);
2816         list_for_each_safe(pos, n, &ext4_li_info->li_request_list) {
2817                 elr = list_entry(pos, struct ext4_li_request,
2818                                  lr_request);
2819                 ext4_remove_li_request(elr);
2820         }
2821         mutex_unlock(&ext4_li_info->li_list_mtx);
2822 }
2823
2824 static int ext4_run_lazyinit_thread(void)
2825 {
2826         struct task_struct *t;
2827
2828         t = kthread_run(ext4_lazyinit_thread, ext4_li_info, "ext4lazyinit");
2829         if (IS_ERR(t)) {
2830                 int err = PTR_ERR(t);
2831                 ext4_clear_request_list();
2832                 del_timer_sync(&ext4_li_info->li_timer);
2833                 kfree(ext4_li_info);
2834                 ext4_li_info = NULL;
2835                 printk(KERN_CRIT "EXT4: error %d creating inode table "
2836                                  "initialization thread\n",
2837                                  err);
2838                 return err;
2839         }
2840         ext4_li_info->li_state |= EXT4_LAZYINIT_RUNNING;
2841
2842         wait_event(ext4_li_info->li_wait_task, ext4_li_info->li_task != NULL);
2843         return 0;
2844 }
2845
2846 /*
2847  * Check whether it make sense to run itable init. thread or not.
2848  * If there is at least one uninitialized inode table, return
2849  * corresponding group number, else the loop goes through all
2850  * groups and return total number of groups.
2851  */
2852 static ext4_group_t ext4_has_uninit_itable(struct super_block *sb)
2853 {
2854         ext4_group_t group, ngroups = EXT4_SB(sb)->s_groups_count;
2855         struct ext4_group_desc *gdp = NULL;
2856
2857         for (group = 0; group < ngroups; group++) {
2858                 gdp = ext4_get_group_desc(sb, group, NULL);
2859                 if (!gdp)
2860                         continue;
2861
2862                 if (!(gdp->bg_flags & cpu_to_le16(EXT4_BG_INODE_ZEROED)))
2863                         break;
2864         }
2865
2866         return group;
2867 }
2868
2869 static int ext4_li_info_new(void)
2870 {
2871         struct ext4_lazy_init *eli = NULL;
2872
2873         eli = kzalloc(sizeof(*eli), GFP_KERNEL);
2874         if (!eli)
2875                 return -ENOMEM;
2876
2877         eli->li_task = NULL;
2878         INIT_LIST_HEAD(&eli->li_request_list);
2879         mutex_init(&eli->li_list_mtx);
2880
2881         init_waitqueue_head(&eli->li_wait_daemon);
2882         init_waitqueue_head(&eli->li_wait_task);
2883         init_timer(&eli->li_timer);
2884         eli->li_state |= EXT4_LAZYINIT_QUIT;
2885
2886         ext4_li_info = eli;
2887
2888         return 0;
2889 }
2890
2891 static struct ext4_li_request *ext4_li_request_new(struct super_block *sb,
2892                                             ext4_group_t start)
2893 {
2894         struct ext4_sb_info *sbi = EXT4_SB(sb);
2895         struct ext4_li_request *elr;
2896         unsigned long rnd;
2897
2898         elr = kzalloc(sizeof(*elr), GFP_KERNEL);
2899         if (!elr)
2900                 return NULL;
2901
2902         elr->lr_super = sb;
2903         elr->lr_sbi = sbi;
2904         elr->lr_next_group = start;
2905
2906         /*
2907          * Randomize first schedule time of the request to
2908          * spread the inode table initialization requests
2909          * better.
2910          */
2911         get_random_bytes(&rnd, sizeof(rnd));
2912         elr->lr_next_sched = jiffies + (unsigned long)rnd %
2913                              (EXT4_DEF_LI_MAX_START_DELAY * HZ);
2914
2915         return elr;
2916 }
2917
2918 static int ext4_register_li_request(struct super_block *sb,
2919                                     ext4_group_t first_not_zeroed)
2920 {
2921         struct ext4_sb_info *sbi = EXT4_SB(sb);
2922         struct ext4_li_request *elr;
2923         ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
2924         int ret;
2925
2926         if (sbi->s_li_request != NULL)
2927                 return 0;
2928
2929         if (first_not_zeroed == ngroups ||
2930             (sb->s_flags & MS_RDONLY) ||
2931             !test_opt(sb, INIT_INODE_TABLE)) {
2932                 sbi->s_li_request = NULL;
2933                 return 0;
2934         }
2935
2936         if (first_not_zeroed == ngroups) {
2937                 sbi->s_li_request = NULL;
2938                 return 0;
2939         }
2940
2941         elr = ext4_li_request_new(sb, first_not_zeroed);
2942         if (!elr)
2943                 return -ENOMEM;
2944
2945         mutex_lock(&ext4_li_mtx);
2946
2947         if (NULL == ext4_li_info) {
2948                 ret = ext4_li_info_new();
2949                 if (ret)
2950                         goto out;
2951         }
2952
2953         mutex_lock(&ext4_li_info->li_list_mtx);
2954         list_add(&elr->lr_request, &ext4_li_info->li_request_list);
2955         mutex_unlock(&ext4_li_info->li_list_mtx);
2956
2957         sbi->s_li_request = elr;
2958
2959         if (!(ext4_li_info->li_state & EXT4_LAZYINIT_RUNNING)) {
2960                 ret = ext4_run_lazyinit_thread();
2961                 if (ret)
2962                         goto out;
2963         }
2964 out:
2965         mutex_unlock(&ext4_li_mtx);
2966         if (ret)
2967                 kfree(elr);
2968         return ret;
2969 }
2970
2971 /*
2972  * We do not need to lock anything since this is called on
2973  * module unload.
2974  */
2975 static void ext4_destroy_lazyinit_thread(void)
2976 {
2977         /*
2978          * If thread exited earlier
2979          * there's nothing to be done.
2980          */
2981         if (!ext4_li_info)
2982                 return;
2983
2984         ext4_clear_request_list();
2985
2986         while (ext4_li_info->li_task) {
2987                 wake_up(&ext4_li_info->li_wait_daemon);
2988                 wait_event(ext4_li_info->li_wait_task,
2989                            ext4_li_info->li_task == NULL);
2990         }
2991 }
2992
2993 static int ext4_fill_super(struct super_block *sb, void *data, int silent)
2994                                 __releases(kernel_lock)
2995                                 __acquires(kernel_lock)
2996 {
2997         char *orig_data = kstrdup(data, GFP_KERNEL);
2998         struct buffer_head *bh;
2999         struct ext4_super_block *es = NULL;
3000         struct ext4_sb_info *sbi;
3001         ext4_fsblk_t block;
3002         ext4_fsblk_t sb_block = get_sb_block(&data);
3003         ext4_fsblk_t logical_sb_block;
3004         unsigned long offset = 0;
3005         unsigned long journal_devnum = 0;
3006         unsigned long def_mount_opts;
3007         struct inode *root;
3008         char *cp;
3009         const char *descr;
3010         int ret = -ENOMEM;
3011         int blocksize;
3012         unsigned int db_count;
3013         unsigned int i;
3014         int needs_recovery, has_huge_files;
3015         __u64 blocks_count;
3016         int err;
3017         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
3018         ext4_group_t first_not_zeroed;
3019
3020         sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
3021         if (!sbi)
3022                 goto out_free_orig;
3023
3024         sbi->s_blockgroup_lock =
3025                 kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL);
3026         if (!sbi->s_blockgroup_lock) {
3027                 kfree(sbi);
3028                 goto out_free_orig;
3029         }
3030         sb->s_fs_info = sbi;
3031         sbi->s_mount_opt = 0;
3032         sbi->s_resuid = EXT4_DEF_RESUID;
3033         sbi->s_resgid = EXT4_DEF_RESGID;
3034         sbi->s_inode_readahead_blks = EXT4_DEF_INODE_READAHEAD_BLKS;
3035         sbi->s_sb_block = sb_block;
3036         if (sb->s_bdev->bd_part)
3037                 sbi->s_sectors_written_start =
3038                         part_stat_read(sb->s_bdev->bd_part, sectors[1]);
3039
3040         /* Cleanup superblock name */
3041         for (cp = sb->s_id; (cp = strchr(cp, '/'));)
3042                 *cp = '!';
3043
3044         ret = -EINVAL;
3045         blocksize = sb_min_blocksize(sb, EXT4_MIN_BLOCK_SIZE);
3046         if (!blocksize) {
3047                 ext4_msg(sb, KERN_ERR, "unable to set blocksize");
3048                 goto out_fail;
3049         }
3050
3051         /*
3052          * The ext4 superblock will not be buffer aligned for other than 1kB
3053          * block sizes.  We need to calculate the offset from buffer start.
3054          */
3055         if (blocksize != EXT4_MIN_BLOCK_SIZE) {
3056                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3057                 offset = do_div(logical_sb_block, blocksize);
3058         } else {
3059                 logical_sb_block = sb_block;
3060         }
3061
3062         if (!(bh = sb_bread(sb, logical_sb_block))) {
3063                 ext4_msg(sb, KERN_ERR, "unable to read superblock");
3064                 goto out_fail;
3065         }
3066         /*
3067          * Note: s_es must be initialized as soon as possible because
3068          *       some ext4 macro-instructions depend on its value
3069          */
3070         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3071         sbi->s_es = es;
3072         sb->s_magic = le16_to_cpu(es->s_magic);
3073         if (sb->s_magic != EXT4_SUPER_MAGIC)
3074                 goto cantfind_ext4;
3075         sbi->s_kbytes_written = le64_to_cpu(es->s_kbytes_written);
3076
3077         /* Set defaults before we parse the mount options */
3078         def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
3079         set_opt(sb, INIT_INODE_TABLE);
3080         if (def_mount_opts & EXT4_DEFM_DEBUG)
3081                 set_opt(sb, DEBUG);
3082         if (def_mount_opts & EXT4_DEFM_BSDGROUPS) {
3083                 ext4_msg(sb, KERN_WARNING, deprecated_msg, "bsdgroups",
3084                         "2.6.38");
3085                 set_opt(sb, GRPID);
3086         }
3087         if (def_mount_opts & EXT4_DEFM_UID16)
3088                 set_opt(sb, NO_UID32);
3089 #ifdef CONFIG_EXT4_FS_XATTR
3090         if (def_mount_opts & EXT4_DEFM_XATTR_USER)
3091                 set_opt(sb, XATTR_USER);
3092 #endif
3093 #ifdef CONFIG_EXT4_FS_POSIX_ACL
3094         if (def_mount_opts & EXT4_DEFM_ACL)
3095                 set_opt(sb, POSIX_ACL);
3096 #endif
3097         if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_DATA)
3098                 set_opt(sb, JOURNAL_DATA);
3099         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_ORDERED)
3100                 set_opt(sb, ORDERED_DATA);
3101         else if ((def_mount_opts & EXT4_DEFM_JMODE) == EXT4_DEFM_JMODE_WBACK)
3102                 set_opt(sb, WRITEBACK_DATA);
3103
3104         if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
3105                 set_opt(sb, ERRORS_PANIC);
3106         else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
3107                 set_opt(sb, ERRORS_CONT);
3108         else
3109                 set_opt(sb, ERRORS_RO);
3110         if (def_mount_opts & EXT4_DEFM_BLOCK_VALIDITY)
3111                 set_opt(sb, BLOCK_VALIDITY);
3112         if (def_mount_opts & EXT4_DEFM_DISCARD)
3113                 set_opt(sb, DISCARD);
3114
3115         sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
3116         sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
3117         sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
3118         sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
3119         sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
3120
3121         if ((def_mount_opts & EXT4_DEFM_NOBARRIER) == 0)
3122                 set_opt(sb, BARRIER);
3123
3124         /*
3125          * enable delayed allocation by default
3126          * Use -o nodelalloc to turn it off
3127          */
3128         if (!IS_EXT3_SB(sb) &&
3129             ((def_mount_opts & EXT4_DEFM_NODELALLOC) == 0))
3130                 set_opt(sb, DELALLOC);
3131
3132         if (!parse_options((char *) sbi->s_es->s_mount_opts, sb,
3133                            &journal_devnum, &journal_ioprio, NULL, 0)) {
3134                 ext4_msg(sb, KERN_WARNING,
3135                          "failed to parse options in superblock: %s",
3136                          sbi->s_es->s_mount_opts);
3137         }
3138         if (!parse_options((char *) data, sb, &journal_devnum,
3139                            &journal_ioprio, NULL, 0))
3140                 goto failed_mount;
3141
3142         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
3143                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
3144
3145         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
3146             (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
3147              EXT4_HAS_RO_COMPAT_FEATURE(sb, ~0U) ||
3148              EXT4_HAS_INCOMPAT_FEATURE(sb, ~0U)))
3149                 ext4_msg(sb, KERN_WARNING,
3150                        "feature flags set on rev 0 fs, "
3151                        "running e2fsck is recommended");
3152
3153         /*
3154          * Check feature flags regardless of the revision level, since we
3155          * previously didn't change the revision level when setting the flags,
3156          * so there is a chance incompat flags are set on a rev 0 filesystem.
3157          */
3158         if (!ext4_feature_set_ok(sb, (sb->s_flags & MS_RDONLY)))
3159                 goto failed_mount;
3160
3161         blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
3162
3163         if (blocksize < EXT4_MIN_BLOCK_SIZE ||
3164             blocksize > EXT4_MAX_BLOCK_SIZE) {
3165                 ext4_msg(sb, KERN_ERR,
3166                        "Unsupported filesystem blocksize %d", blocksize);
3167                 goto failed_mount;
3168         }
3169
3170         if (sb->s_blocksize != blocksize) {
3171                 /* Validate the filesystem blocksize */
3172                 if (!sb_set_blocksize(sb, blocksize)) {
3173                         ext4_msg(sb, KERN_ERR, "bad block size %d",
3174                                         blocksize);
3175                         goto failed_mount;
3176                 }
3177
3178                 brelse(bh);
3179                 logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
3180                 offset = do_div(logical_sb_block, blocksize);
3181                 bh = sb_bread(sb, logical_sb_block);
3182                 if (!bh) {
3183                         ext4_msg(sb, KERN_ERR,
3184                                "Can't read superblock on 2nd try");
3185                         goto failed_mount;
3186                 }
3187                 es = (struct ext4_super_block *)(((char *)bh->b_data) + offset);
3188                 sbi->s_es = es;
3189                 if (es->s_magic != cpu_to_le16(EXT4_SUPER_MAGIC)) {
3190                         ext4_msg(sb, KERN_ERR,
3191                                "Magic mismatch, very weird!");
3192                         goto failed_mount;
3193                 }
3194         }
3195
3196         has_huge_files = EXT4_HAS_RO_COMPAT_FEATURE(sb,
3197                                 EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
3198         sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits,
3199                                                       has_huge_files);
3200         sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits, has_huge_files);
3201
3202         if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
3203                 sbi->s_inode_size = EXT4_GOOD_OLD_INODE_SIZE;
3204                 sbi->s_first_ino = EXT4_GOOD_OLD_FIRST_INO;
3205         } else {
3206                 sbi->s_inode_size = le16_to_cpu(es->s_inode_size);
3207                 sbi->s_first_ino = le32_to_cpu(es->s_first_ino);
3208                 if ((sbi->s_inode_size < EXT4_GOOD_OLD_INODE_SIZE) ||
3209                     (!is_power_of_2(sbi->s_inode_size)) ||
3210                     (sbi->s_inode_size > blocksize)) {
3211                         ext4_msg(sb, KERN_ERR,
3212                                "unsupported inode size: %d",
3213                                sbi->s_inode_size);
3214                         goto failed_mount;
3215                 }
3216                 if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE)
3217                         sb->s_time_gran = 1 << (EXT4_EPOCH_BITS - 2);
3218         }
3219
3220         sbi->s_desc_size = le16_to_cpu(es->s_desc_size);
3221         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) {
3222                 if (sbi->s_desc_size < EXT4_MIN_DESC_SIZE_64BIT ||
3223                     sbi->s_desc_size > EXT4_MAX_DESC_SIZE ||
3224                     !is_power_of_2(sbi->s_desc_size)) {
3225                         ext4_msg(sb, KERN_ERR,
3226                                "unsupported descriptor size %lu",
3227                                sbi->s_desc_size);
3228                         goto failed_mount;
3229                 }
3230         } else
3231                 sbi->s_desc_size = EXT4_MIN_DESC_SIZE;
3232
3233         sbi->s_blocks_per_group = le32_to_cpu(es->s_blocks_per_group);
3234         sbi->s_inodes_per_group = le32_to_cpu(es->s_inodes_per_group);
3235         if (EXT4_INODE_SIZE(sb) == 0 || EXT4_INODES_PER_GROUP(sb) == 0)
3236                 goto cantfind_ext4;
3237
3238         sbi->s_inodes_per_block = blocksize / EXT4_INODE_SIZE(sb);
3239         if (sbi->s_inodes_per_block == 0)
3240                 goto cantfind_ext4;
3241         sbi->s_itb_per_group = sbi->s_inodes_per_group /
3242                                         sbi->s_inodes_per_block;
3243         sbi->s_desc_per_block = blocksize / EXT4_DESC_SIZE(sb);
3244         sbi->s_sbh = bh;
3245         sbi->s_mount_state = le16_to_cpu(es->s_state);
3246         sbi->s_addr_per_block_bits = ilog2(EXT4_ADDR_PER_BLOCK(sb));
3247         sbi->s_desc_per_block_bits = ilog2(EXT4_DESC_PER_BLOCK(sb));
3248
3249         for (i = 0; i < 4; i++)
3250                 sbi->s_hash_seed[i] = le32_to_cpu(es->s_hash_seed[i]);
3251         sbi->s_def_hash_version = es->s_def_hash_version;
3252         i = le32_to_cpu(es->s_flags);
3253         if (i & EXT2_FLAGS_UNSIGNED_HASH)
3254                 sbi->s_hash_unsigned = 3;
3255         else if ((i & EXT2_FLAGS_SIGNED_HASH) == 0) {
3256 #ifdef __CHAR_UNSIGNED__
3257                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH);
3258                 sbi->s_hash_unsigned = 3;
3259 #else
3260                 es->s_flags |= cpu_to_le32(EXT2_FLAGS_SIGNED_HASH);
3261 #endif
3262                 sb->s_dirt = 1;
3263         }
3264
3265         if (sbi->s_blocks_per_group > blocksize * 8) {
3266                 ext4_msg(sb, KERN_ERR,
3267                        "#blocks per group too big: %lu",
3268                        sbi->s_blocks_per_group);
3269                 goto failed_mount;
3270         }
3271         if (sbi->s_inodes_per_group > blocksize * 8) {
3272                 ext4_msg(sb, KERN_ERR,
3273                        "#inodes per group too big: %lu",
3274                        sbi->s_inodes_per_group);
3275                 goto failed_mount;
3276         }
3277
3278         /*
3279          * Test whether we have more sectors than will fit in sector_t,
3280          * and whether the max offset is addressable by the page cache.
3281          */
3282         err = generic_check_addressable(sb->s_blocksize_bits,
3283                                         ext4_blocks_count(es));
3284         if (err) {
3285                 ext4_msg(sb, KERN_ERR, "filesystem"
3286                          " too large to mount safely on this system");
3287                 if (sizeof(sector_t) < 8)
3288                         ext4_msg(sb, KERN_WARNING, "CONFIG_LBDAF not enabled");
3289                 ret = err;
3290                 goto failed_mount;
3291         }
3292
3293         if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
3294                 goto cantfind_ext4;
3295
3296         /* check blocks count against device size */
3297         blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits;
3298         if (blocks_count && ext4_blocks_count(es) > blocks_count) {
3299                 ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu "
3300                        "exceeds size of device (%llu blocks)",
3301                        ext4_blocks_count(es), blocks_count);
3302                 goto failed_mount;
3303         }
3304
3305         /*
3306          * It makes no sense for the first data block to be beyond the end
3307          * of the filesystem.
3308          */
3309         if (le32_to_cpu(es->s_first_data_block) >= ext4_blocks_count(es)) {
3310                 ext4_msg(sb, KERN_WARNING, "bad geometry: first data"
3311                          "block %u is beyond end of filesystem (%llu)",
3312                          le32_to_cpu(es->s_first_data_block),
3313                          ext4_blocks_count(es));
3314                 goto failed_mount;
3315         }
3316         blocks_count = (ext4_blocks_count(es) -
3317                         le32_to_cpu(es->s_first_data_block) +
3318                         EXT4_BLOCKS_PER_GROUP(sb) - 1);
3319         do_div(blocks_count, EXT4_BLOCKS_PER_GROUP(sb));
3320         if (blocks_count > ((uint64_t)1<<32) - EXT4_DESC_PER_BLOCK(sb)) {
3321                 ext4_msg(sb, KERN_WARNING, "groups count too large: %u "
3322                        "(block count %llu, first data block %u, "
3323                        "blocks per group %lu)", sbi->s_groups_count,
3324                        ext4_blocks_count(es),
3325                        le32_to_cpu(es->s_first_data_block),
3326                        EXT4_BLOCKS_PER_GROUP(sb));
3327                 goto failed_mount;
3328         }
3329         sbi->s_groups_count = blocks_count;
3330         sbi->s_blockfile_groups = min_t(ext4_group_t, sbi->s_groups_count,
3331                         (EXT4_MAX_BLOCK_FILE_PHYS / EXT4_BLOCKS_PER_GROUP(sb)));
3332         db_count = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) /
3333                    EXT4_DESC_PER_BLOCK(sb);
3334         sbi->s_group_desc = kmalloc(db_count * sizeof(struct buffer_head *),
3335                                     GFP_KERNEL);
3336         if (sbi->s_group_desc == NULL) {
3337                 ext4_msg(sb, KERN_ERR, "not enough memory");
3338                 goto failed_mount;
3339         }
3340
3341 #ifdef CONFIG_PROC_FS
3342         if (ext4_proc_root)
3343                 sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
3344 #endif
3345
3346         bgl_lock_init(sbi->s_blockgroup_lock);
3347
3348         for (i = 0; i < db_count; i++) {
3349                 block = descriptor_loc(sb, logical_sb_block, i);
3350                 sbi->s_group_desc[i] = sb_bread(sb, block);
3351                 if (!sbi->s_group_desc[i]) {
3352                         ext4_msg(sb, KERN_ERR,
3353                                "can't read group descriptor %d", i);
3354                         db_count = i;
3355                         goto failed_mount2;
3356                 }
3357         }
3358         if (!ext4_check_descriptors(sb, &first_not_zeroed)) {
3359                 ext4_msg(sb, KERN_ERR, "group descriptors corrupted!");
3360                 goto failed_mount2;
3361         }
3362         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
3363                 if (!ext4_fill_flex_info(sb)) {
3364                         ext4_msg(sb, KERN_ERR,
3365                                "unable to initialize "
3366                                "flex_bg meta info!");
3367                         goto failed_mount2;
3368                 }
3369
3370         sbi->s_gdb_count = db_count;
3371         get_random_bytes(&sbi->s_next_generation, sizeof(u32));
3372         spin_lock_init(&sbi->s_next_gen_lock);
3373
3374         err = percpu_counter_init(&sbi->s_freeblocks_counter,
3375                         ext4_count_free_blocks(sb));
3376         if (!err) {
3377                 err = percpu_counter_init(&sbi->s_freeinodes_counter,
3378                                 ext4_count_free_inodes(sb));
3379         }
3380         if (!err) {
3381                 err = percpu_counter_init(&sbi->s_dirs_counter,
3382                                 ext4_count_dirs(sb));
3383         }
3384         if (!err) {
3385                 err = percpu_counter_init(&sbi->s_dirtyblocks_counter, 0);
3386         }
3387         if (err) {
3388                 ext4_msg(sb, KERN_ERR, "insufficient memory");
3389                 goto failed_mount3;
3390         }
3391
3392         sbi->s_stripe = ext4_get_stripe_size(sbi);
3393         sbi->s_max_writeback_mb_bump = 128;
3394
3395         /*
3396          * set up enough so that it can read an inode
3397          */
3398         if (!test_opt(sb, NOLOAD) &&
3399             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
3400                 sb->s_op = &ext4_sops;
3401         else
3402                 sb->s_op = &ext4_nojournal_sops;
3403         sb->s_export_op = &ext4_export_ops;
3404         sb->s_xattr = ext4_xattr_handlers;
3405 #ifdef CONFIG_QUOTA
3406         sb->s_qcop = &ext4_qctl_operations;
3407         sb->dq_op = &ext4_quota_operations;
3408 #endif
3409         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
3410         mutex_init(&sbi->s_orphan_lock);
3411         mutex_init(&sbi->s_resize_lock);
3412
3413         sb->s_root = NULL;
3414
3415         needs_recovery = (es->s_last_orphan != 0 ||
3416                           EXT4_HAS_INCOMPAT_FEATURE(sb,
3417                                     EXT4_FEATURE_INCOMPAT_RECOVER));
3418
3419         /*
3420          * The first inode we look at is the journal inode.  Don't try
3421          * root first: it may be modified in the journal!
3422          */
3423         if (!test_opt(sb, NOLOAD) &&
3424             EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
3425                 if (ext4_load_journal(sb, es, journal_devnum))
3426                         goto failed_mount3;
3427         } else if (test_opt(sb, NOLOAD) && !(sb->s_flags & MS_RDONLY) &&
3428               EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3429                 ext4_msg(sb, KERN_ERR, "required journal recovery "
3430                        "suppressed and not mounted read-only");
3431                 goto failed_mount_wq;
3432         } else {
3433                 clear_opt(sb, DATA_FLAGS);
3434                 set_opt(sb, WRITEBACK_DATA);
3435                 sbi->s_journal = NULL;
3436                 needs_recovery = 0;
3437                 goto no_journal;
3438         }
3439
3440         if (ext4_blocks_count(es) > 0xffffffffULL &&
3441             !jbd2_journal_set_features(EXT4_SB(sb)->s_journal, 0, 0,
3442                                        JBD2_FEATURE_INCOMPAT_64BIT)) {
3443                 ext4_msg(sb, KERN_ERR, "Failed to set 64-bit journal feature");
3444                 goto failed_mount_wq;
3445         }
3446
3447         if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
3448                 jbd2_journal_set_features(sbi->s_journal,
3449                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3450                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3451         } else if (test_opt(sb, JOURNAL_CHECKSUM)) {
3452                 jbd2_journal_set_features(sbi->s_journal,
3453                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
3454                 jbd2_journal_clear_features(sbi->s_journal, 0, 0,
3455                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3456         } else {
3457                 jbd2_journal_clear_features(sbi->s_journal,
3458                                 JBD2_FEATURE_COMPAT_CHECKSUM, 0,
3459                                 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
3460         }
3461
3462         /* We have now updated the journal if required, so we can
3463          * validate the data journaling mode. */
3464         switch (test_opt(sb, DATA_FLAGS)) {
3465         case 0:
3466                 /* No mode set, assume a default based on the journal
3467                  * capabilities: ORDERED_DATA if the journal can
3468                  * cope, else JOURNAL_DATA
3469                  */
3470                 if (jbd2_journal_check_available_features
3471                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE))
3472                         set_opt(sb, ORDERED_DATA);
3473                 else
3474                         set_opt(sb, JOURNAL_DATA);
3475                 break;
3476
3477         case EXT4_MOUNT_ORDERED_DATA:
3478         case EXT4_MOUNT_WRITEBACK_DATA:
3479                 if (!jbd2_journal_check_available_features
3480                     (sbi->s_journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)) {
3481                         ext4_msg(sb, KERN_ERR, "Journal does not support "
3482                                "requested data journaling mode");
3483                         goto failed_mount_wq;
3484                 }
3485         default:
3486                 break;
3487         }
3488         set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
3489
3490         /*
3491          * The journal may have updated the bg summary counts, so we
3492          * need to update the global counters.
3493          */
3494         percpu_counter_set(&sbi->s_freeblocks_counter,
3495                            ext4_count_free_blocks(sb));
3496         percpu_counter_set(&sbi->s_freeinodes_counter,
3497                            ext4_count_free_inodes(sb));
3498         percpu_counter_set(&sbi->s_dirs_counter,
3499                            ext4_count_dirs(sb));
3500         percpu_counter_set(&sbi->s_dirtyblocks_counter, 0);
3501
3502 no_journal:
3503         EXT4_SB(sb)->dio_unwritten_wq = create_workqueue("ext4-dio-unwritten");
3504         if (!EXT4_SB(sb)->dio_unwritten_wq) {
3505                 printk(KERN_ERR "EXT4-fs: failed to create DIO workqueue\n");
3506                 goto failed_mount_wq;
3507         }
3508
3509         /*
3510          * The jbd2_journal_load will have done any necessary log recovery,
3511          * so we can safely mount the rest of the filesystem now.
3512          */
3513
3514         root = ext4_iget(sb, EXT4_ROOT_INO);
3515         if (IS_ERR(root)) {
3516                 ext4_msg(sb, KERN_ERR, "get root inode failed");
3517                 ret = PTR_ERR(root);
3518                 goto failed_mount4;
3519         }
3520         if (!S_ISDIR(root->i_mode) || !root->i_blocks || !root->i_size) {
3521                 iput(root);
3522                 ext4_msg(sb, KERN_ERR, "corrupt root inode, run e2fsck");
3523                 goto failed_mount4;
3524         }
3525         sb->s_root = d_alloc_root(root);
3526         if (!sb->s_root) {
3527                 ext4_msg(sb, KERN_ERR, "get root dentry failed");
3528                 iput(root);
3529                 ret = -ENOMEM;
3530                 goto failed_mount4;
3531         }
3532
3533         ext4_setup_super(sb, es, sb->s_flags & MS_RDONLY);
3534
3535         /* determine the minimum size of new large inodes, if present */
3536         if (sbi->s_inode_size > EXT4_GOOD_OLD_INODE_SIZE) {
3537                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3538                                                      EXT4_GOOD_OLD_INODE_SIZE;
3539                 if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
3540                                        EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE)) {
3541                         if (sbi->s_want_extra_isize <
3542                             le16_to_cpu(es->s_want_extra_isize))
3543                                 sbi->s_want_extra_isize =
3544                                         le16_to_cpu(es->s_want_extra_isize);
3545                         if (sbi->s_want_extra_isize <
3546                             le16_to_cpu(es->s_min_extra_isize))
3547                                 sbi->s_want_extra_isize =
3548                                         le16_to_cpu(es->s_min_extra_isize);
3549                 }
3550         }
3551         /* Check if enough inode space is available */
3552         if (EXT4_GOOD_OLD_INODE_SIZE + sbi->s_want_extra_isize >
3553                                                         sbi->s_inode_size) {
3554                 sbi->s_want_extra_isize = sizeof(struct ext4_inode) -
3555                                                        EXT4_GOOD_OLD_INODE_SIZE;
3556                 ext4_msg(sb, KERN_INFO, "required extra inode space not"
3557                          "available");
3558         }
3559
3560         if (test_opt(sb, DELALLOC) &&
3561             (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)) {
3562                 ext4_msg(sb, KERN_WARNING, "Ignoring delalloc option - "
3563                          "requested data journaling mode");
3564                 clear_opt(sb, DELALLOC);
3565         }
3566         if (test_opt(sb, DIOREAD_NOLOCK)) {
3567                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA) {
3568                         ext4_msg(sb, KERN_WARNING, "Ignoring dioread_nolock "
3569                                 "option - requested data journaling mode");
3570                         clear_opt(sb, DIOREAD_NOLOCK);
3571                 }
3572                 if (sb->s_blocksize < PAGE_SIZE) {
3573                         ext4_msg(sb, KERN_WARNING, "Ignoring dioread_nolock "
3574                                 "option - block size is too small");
3575                         clear_opt(sb, DIOREAD_NOLOCK);
3576                 }
3577         }
3578
3579         err = ext4_setup_system_zone(sb);
3580         if (err) {
3581                 ext4_msg(sb, KERN_ERR, "failed to initialize system "
3582                          "zone (%d)", err);
3583                 goto failed_mount4;
3584         }
3585
3586         ext4_ext_init(sb);
3587         err = ext4_mb_init(sb, needs_recovery);
3588         if (err) {
3589                 ext4_msg(sb, KERN_ERR, "failed to initialize mballoc (%d)",
3590                          err);
3591                 goto failed_mount4;
3592         }
3593
3594         err = ext4_register_li_request(sb, first_not_zeroed);
3595         if (err)
3596                 goto failed_mount4;
3597
3598         sbi->s_kobj.kset = ext4_kset;
3599         init_completion(&sbi->s_kobj_unregister);
3600         err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
3601                                    "%s", sb->s_id);
3602         if (err) {
3603                 ext4_mb_release(sb);
3604                 ext4_ext_release(sb);
3605                 goto failed_mount4;
3606         };
3607
3608         EXT4_SB(sb)->s_mount_state |= EXT4_ORPHAN_FS;
3609         ext4_orphan_cleanup(sb, es);
3610         EXT4_SB(sb)->s_mount_state &= ~EXT4_ORPHAN_FS;
3611         if (needs_recovery) {
3612                 ext4_msg(sb, KERN_INFO, "recovery complete");
3613                 ext4_mark_recovery_complete(sb, es);
3614         }
3615         if (EXT4_SB(sb)->s_journal) {
3616                 if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
3617                         descr = " journalled data mode";
3618                 else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
3619                         descr = " ordered data mode";
3620                 else
3621                         descr = " writeback data mode";
3622         } else
3623                 descr = "out journal";
3624
3625         ext4_msg(sb, KERN_INFO, "mounted filesystem with%s. "
3626                  "Opts: %s%s%s", descr, sbi->s_es->s_mount_opts,
3627                  *sbi->s_es->s_mount_opts ? "; " : "", orig_data);
3628
3629         init_timer(&sbi->s_err_report);
3630         sbi->s_err_report.function = print_daily_error_info;
3631         sbi->s_err_report.data = (unsigned long) sb;
3632         if (es->s_error_count)
3633                 mod_timer(&sbi->s_err_report, jiffies + 300*HZ); /* 5 minutes */
3634
3635         kfree(orig_data);
3636         return 0;
3637
3638 cantfind_ext4:
3639         if (!silent)
3640                 ext4_msg(sb, KERN_ERR, "VFS: Can't find ext4 filesystem");
3641         goto failed_mount;
3642
3643 failed_mount4:
3644         ext4_msg(sb, KERN_ERR, "mount failed");
3645         destroy_workqueue(EXT4_SB(sb)->dio_unwritten_wq);
3646 failed_mount_wq:
3647         ext4_release_system_zone(sb);
3648         if (sbi->s_journal) {
3649                 jbd2_journal_destroy(sbi->s_journal);
3650                 sbi->s_journal = NULL;
3651         }
3652 failed_mount3:
3653         if (sbi->s_flex_groups) {
3654                 if (is_vmalloc_addr(sbi->s_flex_groups))
3655                         vfree(sbi->s_flex_groups);
3656                 else
3657                         kfree(sbi->s_flex_groups);
3658         }
3659         percpu_counter_destroy(&sbi->s_freeblocks_counter);
3660         percpu_counter_destroy(&sbi->s_freeinodes_counter);
3661         percpu_counter_destroy(&sbi->s_dirs_counter);
3662         percpu_counter_destroy(&sbi->s_dirtyblocks_counter);
3663 failed_mount2:
3664         for (i = 0; i < db_count; i++)
3665                 brelse(sbi->s_group_desc[i]);
3666         kfree(sbi->s_group_desc);
3667 failed_mount:
3668         if (sbi->s_proc) {
3669                 remove_proc_entry(sb->s_id, ext4_proc_root);
3670         }
3671 #ifdef CONFIG_QUOTA
3672         for (i = 0; i < MAXQUOTAS; i++)
3673                 kfree(sbi->s_qf_names[i]);
3674 #endif
3675         ext4_blkdev_remove(sbi);
3676         brelse(bh);
3677 out_fail:
3678         sb->s_fs_info = NULL;
3679         kfree(sbi->s_blockgroup_lock);
3680         kfree(sbi);
3681 out_free_orig:
3682         kfree(orig_data);
3683         return ret;
3684 }
3685
3686 /*
3687  * Setup any per-fs journal parameters now.  We'll do this both on
3688  * initial mount, once the journal has been initialised but before we've
3689  * done any recovery; and again on any subsequent remount.
3690  */
3691 static void ext4_init_journal_params(struct super_block *sb, journal_t *journal)
3692 {
3693         struct ext4_sb_info *sbi = EXT4_SB(sb);
3694
3695         journal->j_commit_interval = sbi->s_commit_interval;
3696         journal->j_min_batch_time = sbi->s_min_batch_time;
3697         journal->j_max_batch_time = sbi->s_max_batch_time;
3698
3699         write_lock(&journal->j_state_lock);
3700         if (test_opt(sb, BARRIER))
3701                 journal->j_flags |= JBD2_BARRIER;
3702         else
3703                 journal->j_flags &= ~JBD2_BARRIER;
3704         if (test_opt(sb, DATA_ERR_ABORT))
3705                 journal->j_flags |= JBD2_ABORT_ON_SYNCDATA_ERR;
3706         else
3707                 journal->j_flags &= ~JBD2_ABORT_ON_SYNCDATA_ERR;
3708         write_unlock(&journal->j_state_lock);
3709 }
3710
3711 static journal_t *ext4_get_journal(struct super_block *sb,
3712                                    unsigned int journal_inum)
3713 {
3714         struct inode *journal_inode;
3715         journal_t *journal;
3716
3717         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3718
3719         /* First, test for the existence of a valid inode on disk.  Bad
3720          * things happen if we iget() an unused inode, as the subsequent
3721          * iput() will try to delete it. */
3722
3723         journal_inode = ext4_iget(sb, journal_inum);
3724         if (IS_ERR(journal_inode)) {
3725                 ext4_msg(sb, KERN_ERR, "no journal found");
3726                 return NULL;
3727         }
3728         if (!journal_inode->i_nlink) {
3729                 make_bad_inode(journal_inode);
3730                 iput(journal_inode);
3731                 ext4_msg(sb, KERN_ERR, "journal inode is deleted");
3732                 return NULL;
3733         }
3734
3735         jbd_debug(2, "Journal inode found at %p: %lld bytes\n",
3736                   journal_inode, journal_inode->i_size);
3737         if (!S_ISREG(journal_inode->i_mode)) {
3738                 ext4_msg(sb, KERN_ERR, "invalid journal inode");
3739                 iput(journal_inode);
3740                 return NULL;
3741         }
3742
3743         journal = jbd2_journal_init_inode(journal_inode);
3744         if (!journal) {
3745                 ext4_msg(sb, KERN_ERR, "Could not load journal inode");
3746                 iput(journal_inode);
3747                 return NULL;
3748         }
3749         journal->j_private = sb;
3750         ext4_init_journal_params(sb, journal);
3751         return journal;
3752 }
3753
3754 static journal_t *ext4_get_dev_journal(struct super_block *sb,
3755                                        dev_t j_dev)
3756 {
3757         struct buffer_head *bh;
3758         journal_t *journal;
3759         ext4_fsblk_t start;
3760         ext4_fsblk_t len;
3761         int hblock, blocksize;
3762         ext4_fsblk_t sb_block;
3763         unsigned long offset;
3764         struct ext4_super_block *es;
3765         struct block_device *bdev;
3766
3767         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3768
3769         bdev = ext4_blkdev_get(j_dev, sb);
3770         if (bdev == NULL)
3771                 return NULL;
3772
3773         if (bd_claim(bdev, sb)) {
3774                 ext4_msg(sb, KERN_ERR,
3775                         "failed to claim external journal device");
3776                 blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
3777                 return NULL;
3778         }
3779
3780         blocksize = sb->s_blocksize;
3781         hblock = bdev_logical_block_size(bdev);
3782         if (blocksize < hblock) {
3783                 ext4_msg(sb, KERN_ERR,
3784                         "blocksize too small for journal device");
3785                 goto out_bdev;
3786         }
3787
3788         sb_block = EXT4_MIN_BLOCK_SIZE / blocksize;
3789         offset = EXT4_MIN_BLOCK_SIZE % blocksize;
3790         set_blocksize(bdev, blocksize);
3791         if (!(bh = __bread(bdev, sb_block, blocksize))) {
3792                 ext4_msg(sb, KERN_ERR, "couldn't read superblock of "
3793                        "external journal");
3794                 goto out_bdev;
3795         }
3796
3797         es = (struct ext4_super_block *) (((char *)bh->b_data) + offset);
3798         if ((le16_to_cpu(es->s_magic) != EXT4_SUPER_MAGIC) ||
3799             !(le32_to_cpu(es->s_feature_incompat) &
3800               EXT4_FEATURE_INCOMPAT_JOURNAL_DEV)) {
3801                 ext4_msg(sb, KERN_ERR, "external journal has "
3802                                         "bad superblock");
3803                 brelse(bh);
3804                 goto out_bdev;
3805         }
3806
3807         if (memcmp(EXT4_SB(sb)->s_es->s_journal_uuid, es->s_uuid, 16)) {
3808                 ext4_msg(sb, KERN_ERR, "journal UUID does not match");
3809                 brelse(bh);
3810                 goto out_bdev;
3811         }
3812
3813         len = ext4_blocks_count(es);
3814         start = sb_block + 1;
3815         brelse(bh);     /* we're done with the superblock */
3816
3817         journal = jbd2_journal_init_dev(bdev, sb->s_bdev,
3818                                         start, len, blocksize);
3819         if (!journal) {
3820                 ext4_msg(sb, KERN_ERR, "failed to create device journal");
3821                 goto out_bdev;
3822         }
3823         journal->j_private = sb;
3824         ll_rw_block(READ, 1, &journal->j_sb_buffer);
3825         wait_on_buffer(journal->j_sb_buffer);
3826         if (!buffer_uptodate(journal->j_sb_buffer)) {
3827                 ext4_msg(sb, KERN_ERR, "I/O error on journal device");
3828                 goto out_journal;
3829         }
3830         if (be32_to_cpu(journal->j_superblock->s_nr_users) != 1) {
3831                 ext4_msg(sb, KERN_ERR, "External journal has more than one "
3832                                         "user (unsupported) - %d",
3833                         be32_to_cpu(journal->j_superblock->s_nr_users));
3834                 goto out_journal;
3835         }
3836         EXT4_SB(sb)->journal_bdev = bdev;
3837         ext4_init_journal_params(sb, journal);
3838         return journal;
3839
3840 out_journal:
3841         jbd2_journal_destroy(journal);
3842 out_bdev:
3843         ext4_blkdev_put(bdev);
3844         return NULL;
3845 }
3846
3847 static int ext4_load_journal(struct super_block *sb,
3848                              struct ext4_super_block *es,
3849                              unsigned long journal_devnum)
3850 {
3851         journal_t *journal;
3852         unsigned int journal_inum = le32_to_cpu(es->s_journal_inum);
3853         dev_t journal_dev;
3854         int err = 0;
3855         int really_read_only;
3856
3857         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
3858
3859         if (journal_devnum &&
3860             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3861                 ext4_msg(sb, KERN_INFO, "external journal device major/minor "
3862                         "numbers have changed");
3863                 journal_dev = new_decode_dev(journal_devnum);
3864         } else
3865                 journal_dev = new_decode_dev(le32_to_cpu(es->s_journal_dev));
3866
3867         really_read_only = bdev_read_only(sb->s_bdev);
3868
3869         /*
3870          * Are we loading a blank journal or performing recovery after a
3871          * crash?  For recovery, we need to check in advance whether we
3872          * can get read-write access to the device.
3873          */
3874         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER)) {
3875                 if (sb->s_flags & MS_RDONLY) {
3876                         ext4_msg(sb, KERN_INFO, "INFO: recovery "
3877                                         "required on readonly filesystem");
3878                         if (really_read_only) {
3879                                 ext4_msg(sb, KERN_ERR, "write access "
3880                                         "unavailable, cannot proceed");
3881                                 return -EROFS;
3882                         }
3883                         ext4_msg(sb, KERN_INFO, "write access will "
3884                                "be enabled during recovery");
3885                 }
3886         }
3887
3888         if (journal_inum && journal_dev) {
3889                 ext4_msg(sb, KERN_ERR, "filesystem has both journal "
3890                        "and inode journals!");
3891                 return -EINVAL;
3892         }
3893
3894         if (journal_inum) {
3895                 if (!(journal = ext4_get_journal(sb, journal_inum)))
3896                         return -EINVAL;
3897         } else {
3898                 if (!(journal = ext4_get_dev_journal(sb, journal_dev)))
3899                         return -EINVAL;
3900         }
3901
3902         if (!(journal->j_flags & JBD2_BARRIER))
3903                 ext4_msg(sb, KERN_INFO, "barriers disabled");
3904
3905         if (!really_read_only && test_opt(sb, UPDATE_JOURNAL)) {
3906                 err = jbd2_journal_update_format(journal);
3907                 if (err)  {
3908                         ext4_msg(sb, KERN_ERR, "error updating journal");
3909                         jbd2_journal_destroy(journal);
3910                         return err;
3911                 }
3912         }
3913
3914         if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER))
3915                 err = jbd2_journal_wipe(journal, !really_read_only);
3916         if (!err) {
3917                 char *save = kmalloc(EXT4_S_ERR_LEN, GFP_KERNEL);
3918                 if (save)
3919                         memcpy(save, ((char *) es) +
3920                                EXT4_S_ERR_START, EXT4_S_ERR_LEN);
3921                 err = jbd2_journal_load(journal);
3922                 if (save)
3923                         memcpy(((char *) es) + EXT4_S_ERR_START,
3924                                save, EXT4_S_ERR_LEN);
3925                 kfree(save);
3926         }
3927
3928         if (err) {
3929                 ext4_msg(sb, KERN_ERR, "error loading journal");
3930                 jbd2_journal_destroy(journal);
3931                 return err;
3932         }
3933
3934         EXT4_SB(sb)->s_journal = journal;
3935         ext4_clear_journal_err(sb, es);
3936
3937         if (!really_read_only && journal_devnum &&
3938             journal_devnum != le32_to_cpu(es->s_journal_dev)) {
3939                 es->s_journal_dev = cpu_to_le32(journal_devnum);
3940
3941                 /* Make sure we flush the recovery flag to disk. */
3942                 ext4_commit_super(sb, 1);
3943         }
3944
3945         return 0;
3946 }
3947
3948 static int ext4_commit_super(struct super_block *sb, int sync)
3949 {
3950         struct ext4_super_block *es = EXT4_SB(sb)->s_es;
3951         struct buffer_head *sbh = EXT4_SB(sb)->s_sbh;
3952         int error = 0;
3953
3954         if (!sbh)
3955                 return error;
3956         if (buffer_write_io_error(sbh)) {
3957                 /*
3958                  * Oh, dear.  A previous attempt to write the
3959                  * superblock failed.  This could happen because the
3960                  * USB device was yanked out.  Or it could happen to
3961                  * be a transient write error and maybe the block will
3962                  * be remapped.  Nothing we can do but to retry the
3963                  * write and hope for the best.
3964                  */
3965                 ext4_msg(sb, KERN_ERR, "previous I/O error to "
3966                        "superblock detected");
3967                 clear_buffer_write_io_error(sbh);
3968                 set_buffer_uptodate(sbh);
3969         }
3970         /*
3971          * If the file system is mounted read-only, don't update the
3972          * superblock write time.  This avoids updating the superblock
3973          * write time when we are mounting the root file system
3974          * read/only but we need to replay the journal; at that point,
3975          * for people who are east of GMT and who make their clock
3976          * tick in localtime for Windows bug-for-bug compatibility,
3977          * the clock is set in the future, and this will cause e2fsck
3978          * to complain and force a full file system check.
3979          */
3980         if (!(sb->s_flags & MS_RDONLY))
3981                 es->s_wtime = cpu_to_le32(get_seconds());
3982         if (sb->s_bdev->bd_part)
3983                 es->s_kbytes_written =
3984                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written +
3985                             ((part_stat_read(sb->s_bdev->bd_part, sectors[1]) -
3986                               EXT4_SB(sb)->s_sectors_written_start) >> 1));
3987         else
3988                 es->s_kbytes_written =
3989                         cpu_to_le64(EXT4_SB(sb)->s_kbytes_written);
3990         ext4_free_blocks_count_set(es, percpu_counter_sum_positive(
3991                                            &EXT4_SB(sb)->s_freeblocks_counter));
3992         es->s_free_inodes_count =
3993                 cpu_to_le32(percpu_counter_sum_positive(
3994                                 &EXT4_SB(sb)->s_freeinodes_counter));
3995         sb->s_dirt = 0;
3996         BUFFER_TRACE(sbh, "marking dirty");
3997         mark_buffer_dirty(sbh);
3998         if (sync) {
3999                 error = sync_dirty_buffer(sbh);
4000                 if (error)
4001                         return error;
4002
4003                 error = buffer_write_io_error(sbh);
4004                 if (error) {
4005                         ext4_msg(sb, KERN_ERR, "I/O error while writing "
4006                                "superblock");
4007                         clear_buffer_write_io_error(sbh);
4008                         set_buffer_uptodate(sbh);
4009                 }
4010         }
4011         return error;
4012 }
4013
4014 /*
4015  * Have we just finished recovery?  If so, and if we are mounting (or
4016  * remounting) the filesystem readonly, then we will end up with a
4017  * consistent fs on disk.  Record that fact.
4018  */
4019 static void ext4_mark_recovery_complete(struct super_block *sb,
4020                                         struct ext4_super_block *es)
4021 {
4022         journal_t *journal = EXT4_SB(sb)->s_journal;
4023
4024         if (!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL)) {
4025                 BUG_ON(journal != NULL);
4026                 return;
4027         }
4028         jbd2_journal_lock_updates(journal);
4029         if (jbd2_journal_flush(journal) < 0)
4030                 goto out;
4031
4032         if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER) &&
4033             sb->s_flags & MS_RDONLY) {
4034                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4035                 ext4_commit_super(sb, 1);
4036         }
4037
4038 out:
4039         jbd2_journal_unlock_updates(journal);
4040 }
4041
4042 /*
4043  * If we are mounting (or read-write remounting) a filesystem whose journal
4044  * has recorded an error from a previous lifetime, move that error to the
4045  * main filesystem now.
4046  */
4047 static void ext4_clear_journal_err(struct super_block *sb,
4048                                    struct ext4_super_block *es)
4049 {
4050         journal_t *journal;
4051         int j_errno;
4052         const char *errstr;
4053
4054         BUG_ON(!EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL));
4055
4056         journal = EXT4_SB(sb)->s_journal;
4057
4058         /*
4059          * Now check for any error status which may have been recorded in the
4060          * journal by a prior ext4_error() or ext4_abort()
4061          */
4062
4063         j_errno = jbd2_journal_errno(journal);
4064         if (j_errno) {
4065                 char nbuf[16];
4066
4067                 errstr = ext4_decode_error(sb, j_errno, nbuf);
4068                 ext4_warning(sb, "Filesystem error recorded "
4069                              "from previous mount: %s", errstr);
4070                 ext4_warning(sb, "Marking fs in need of filesystem check.");
4071
4072                 EXT4_SB(sb)->s_mount_state |= EXT4_ERROR_FS;
4073                 es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
4074                 ext4_commit_super(sb, 1);
4075
4076                 jbd2_journal_clear_err(journal);
4077         }
4078 }
4079
4080 /*
4081  * Force the running and committing transactions to commit,
4082  * and wait on the commit.
4083  */
4084 int ext4_force_commit(struct super_block *sb)
4085 {
4086         journal_t *journal;
4087         int ret = 0;
4088
4089         if (sb->s_flags & MS_RDONLY)
4090                 return 0;
4091
4092         journal = EXT4_SB(sb)->s_journal;
4093         if (journal) {
4094                 vfs_check_frozen(sb, SB_FREEZE_TRANS);
4095                 ret = ext4_journal_force_commit(journal);
4096         }
4097
4098         return ret;
4099 }
4100
4101 static void ext4_write_super(struct super_block *sb)
4102 {
4103         lock_super(sb);
4104         ext4_commit_super(sb, 1);
4105         unlock_super(sb);
4106 }
4107
4108 static int ext4_sync_fs(struct super_block *sb, int wait)
4109 {
4110         int ret = 0;
4111         tid_t target;
4112         struct ext4_sb_info *sbi = EXT4_SB(sb);
4113
4114         trace_ext4_sync_fs(sb, wait);
4115         flush_workqueue(sbi->dio_unwritten_wq);
4116         if (jbd2_journal_start_commit(sbi->s_journal, &target)) {
4117                 if (wait)
4118                         jbd2_log_wait_commit(sbi->s_journal, target);
4119         }
4120         return ret;
4121 }
4122
4123 /*
4124  * LVM calls this function before a (read-only) snapshot is created.  This
4125  * gives us a chance to flush the journal completely and mark the fs clean.
4126  */
4127 static int ext4_freeze(struct super_block *sb)
4128 {
4129         int error = 0;
4130         journal_t *journal;
4131
4132         if (sb->s_flags & MS_RDONLY)
4133                 return 0;
4134
4135         journal = EXT4_SB(sb)->s_journal;
4136
4137         /* Now we set up the journal barrier. */
4138         jbd2_journal_lock_updates(journal);
4139
4140         /*
4141          * Don't clear the needs_recovery flag if we failed to flush
4142          * the journal.
4143          */
4144         error = jbd2_journal_flush(journal);
4145         if (error < 0)
4146                 goto out;
4147
4148         /* Journal blocked and flushed, clear needs_recovery flag. */
4149         EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4150         error = ext4_commit_super(sb, 1);
4151 out:
4152         /* we rely on s_frozen to stop further updates */
4153         jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4154         return error;
4155 }
4156
4157 /*
4158  * Called by LVM after the snapshot is done.  We need to reset the RECOVER
4159  * flag here, even though the filesystem is not technically dirty yet.
4160  */
4161 static int ext4_unfreeze(struct super_block *sb)
4162 {
4163         if (sb->s_flags & MS_RDONLY)
4164                 return 0;
4165
4166         lock_super(sb);
4167         /* Reset the needs_recovery flag before the fs is unlocked. */
4168         EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
4169         ext4_commit_super(sb, 1);
4170         unlock_super(sb);
4171         return 0;
4172 }
4173
4174 /*
4175  * Structure to save mount options for ext4_remount's benefit
4176  */
4177 struct ext4_mount_options {
4178         unsigned long s_mount_opt;
4179         unsigned long s_mount_opt2;
4180         uid_t s_resuid;
4181         gid_t s_resgid;
4182         unsigned long s_commit_interval;
4183         u32 s_min_batch_time, s_max_batch_time;
4184 #ifdef CONFIG_QUOTA
4185         int s_jquota_fmt;
4186         char *s_qf_names[MAXQUOTAS];
4187 #endif
4188 };
4189
4190 static int ext4_remount(struct super_block *sb, int *flags, char *data)
4191 {
4192         struct ext4_super_block *es;
4193         struct ext4_sb_info *sbi = EXT4_SB(sb);
4194         ext4_fsblk_t n_blocks_count = 0;
4195         unsigned long old_sb_flags;
4196         struct ext4_mount_options old_opts;
4197         int enable_quota = 0;
4198         ext4_group_t g;
4199         unsigned int journal_ioprio = DEFAULT_JOURNAL_IOPRIO;
4200         int err;
4201 #ifdef CONFIG_QUOTA
4202         int i;
4203 #endif
4204         char *orig_data = kstrdup(data, GFP_KERNEL);
4205
4206         /* Store the original options */
4207         lock_super(sb);
4208         old_sb_flags = sb->s_flags;
4209         old_opts.s_mount_opt = sbi->s_mount_opt;
4210         old_opts.s_mount_opt2 = sbi->s_mount_opt2;
4211         old_opts.s_resuid = sbi->s_resuid;
4212         old_opts.s_resgid = sbi->s_resgid;
4213         old_opts.s_commit_interval = sbi->s_commit_interval;
4214         old_opts.s_min_batch_time = sbi->s_min_batch_time;
4215         old_opts.s_max_batch_time = sbi->s_max_batch_time;
4216 #ifdef CONFIG_QUOTA
4217         old_opts.s_jquota_fmt = sbi->s_jquota_fmt;
4218         for (i = 0; i < MAXQUOTAS; i++)
4219                 old_opts.s_qf_names[i] = sbi->s_qf_names[i];
4220 #endif
4221         if (sbi->s_journal && sbi->s_journal->j_task->io_context)
4222                 journal_ioprio = sbi->s_journal->j_task->io_context->ioprio;
4223
4224         /*
4225          * Allow the "check" option to be passed as a remount option.
4226          */
4227         if (!parse_options(data, sb, NULL, &journal_ioprio,
4228                            &n_blocks_count, 1)) {
4229                 err = -EINVAL;
4230                 goto restore_opts;
4231         }
4232
4233         if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
4234                 ext4_abort(sb, "Abort forced by user");
4235
4236         sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
4237                 (test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
4238
4239         es = sbi->s_es;
4240
4241         if (sbi->s_journal) {
4242                 ext4_init_journal_params(sb, sbi->s_journal);
4243                 set_task_ioprio(sbi->s_journal->j_task, journal_ioprio);
4244         }
4245
4246         if ((*flags & MS_RDONLY) != (sb->s_flags & MS_RDONLY) ||
4247                 n_blocks_count > ext4_blocks_count(es)) {
4248                 if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED) {
4249                         err = -EROFS;
4250                         goto restore_opts;
4251                 }
4252
4253                 if (*flags & MS_RDONLY) {
4254                         err = dquot_suspend(sb, -1);
4255                         if (err < 0)
4256                                 goto restore_opts;
4257
4258                         /*
4259                          * First of all, the unconditional stuff we have to do
4260                          * to disable replay of the journal when we next remount
4261                          */
4262                         sb->s_flags |= MS_RDONLY;
4263
4264                         /*
4265                          * OK, test if we are remounting a valid rw partition
4266                          * readonly, and if so set the rdonly flag and then
4267                          * mark the partition as valid again.
4268                          */
4269                         if (!(es->s_state & cpu_to_le16(EXT4_VALID_FS)) &&
4270                             (sbi->s_mount_state & EXT4_VALID_FS))
4271                                 es->s_state = cpu_to_le16(sbi->s_mount_state);
4272
4273                         if (sbi->s_journal)
4274                                 ext4_mark_recovery_complete(sb, es);
4275                 } else {
4276                         /* Make sure we can mount this feature set readwrite */
4277                         if (!ext4_feature_set_ok(sb, 0)) {
4278                                 err = -EROFS;
4279                                 goto restore_opts;
4280                         }
4281                         /*
4282                          * Make sure the group descriptor checksums
4283                          * are sane.  If they aren't, refuse to remount r/w.
4284                          */
4285                         for (g = 0; g < sbi->s_groups_count; g++) {
4286                                 struct ext4_group_desc *gdp =
4287                                         ext4_get_group_desc(sb, g, NULL);
4288
4289                                 if (!ext4_group_desc_csum_verify(sbi, g, gdp)) {
4290                                         ext4_msg(sb, KERN_ERR,
4291                "ext4_remount: Checksum for group %u failed (%u!=%u)",
4292                 g, le16_to_cpu(ext4_group_desc_csum(sbi, g, gdp)),
4293                                                le16_to_cpu(gdp->bg_checksum));
4294                                         err = -EINVAL;
4295                                         goto restore_opts;
4296                                 }
4297                         }
4298
4299                         /*
4300                          * If we have an unprocessed orphan list hanging
4301                          * around from a previously readonly bdev mount,
4302                          * require a full umount/remount for now.
4303                          */
4304                         if (es->s_last_orphan) {
4305                                 ext4_msg(sb, KERN_WARNING, "Couldn't "
4306                                        "remount RDWR because of unprocessed "
4307                                        "orphan inode list.  Please "
4308                                        "umount/remount instead");
4309                                 err = -EINVAL;
4310                                 goto restore_opts;
4311                         }
4312
4313                         /*
4314                          * Mounting a RDONLY partition read-write, so reread
4315                          * and store the current valid flag.  (It may have
4316                          * been changed by e2fsck since we originally mounted
4317                          * the partition.)
4318                          */
4319                         if (sbi->s_journal)
4320                                 ext4_clear_journal_err(sb, es);
4321                         sbi->s_mount_state = le16_to_cpu(es->s_state);
4322                         if ((err = ext4_group_extend(sb, es, n_blocks_count)))
4323                                 goto restore_opts;
4324                         if (!ext4_setup_super(sb, es, 0))
4325                                 sb->s_flags &= ~MS_RDONLY;
4326                         enable_quota = 1;
4327                 }
4328         }
4329
4330         /*
4331          * Reinitialize lazy itable initialization thread based on
4332          * current settings
4333          */
4334         if ((sb->s_flags & MS_RDONLY) || !test_opt(sb, INIT_INODE_TABLE))
4335                 ext4_unregister_li_request(sb);
4336         else {
4337                 ext4_group_t first_not_zeroed;
4338                 first_not_zeroed = ext4_has_uninit_itable(sb);
4339                 ext4_register_li_request(sb, first_not_zeroed);
4340         }
4341
4342         ext4_setup_system_zone(sb);
4343         if (sbi->s_journal == NULL)
4344                 ext4_commit_super(sb, 1);
4345
4346 #ifdef CONFIG_QUOTA
4347         /* Release old quota file names */
4348         for (i = 0; i < MAXQUOTAS; i++)
4349                 if (old_opts.s_qf_names[i] &&
4350                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4351                         kfree(old_opts.s_qf_names[i]);
4352 #endif
4353         unlock_super(sb);
4354         if (enable_quota)
4355                 dquot_resume(sb, -1);
4356
4357         ext4_msg(sb, KERN_INFO, "re-mounted. Opts: %s", orig_data);
4358         kfree(orig_data);
4359         return 0;
4360
4361 restore_opts:
4362         sb->s_flags = old_sb_flags;
4363         sbi->s_mount_opt = old_opts.s_mount_opt;
4364         sbi->s_mount_opt2 = old_opts.s_mount_opt2;
4365         sbi->s_resuid = old_opts.s_resuid;
4366         sbi->s_resgid = old_opts.s_resgid;
4367         sbi->s_commit_interval = old_opts.s_commit_interval;
4368         sbi->s_min_batch_time = old_opts.s_min_batch_time;
4369         sbi->s_max_batch_time = old_opts.s_max_batch_time;
4370 #ifdef CONFIG_QUOTA
4371         sbi->s_jquota_fmt = old_opts.s_jquota_fmt;
4372         for (i = 0; i < MAXQUOTAS; i++) {
4373                 if (sbi->s_qf_names[i] &&
4374                     old_opts.s_qf_names[i] != sbi->s_qf_names[i])
4375                         kfree(sbi->s_qf_names[i]);
4376                 sbi->s_qf_names[i] = old_opts.s_qf_names[i];
4377         }
4378 #endif
4379         unlock_super(sb);
4380         kfree(orig_data);
4381         return err;
4382 }
4383
4384 static int ext4_statfs(struct dentry *dentry, struct kstatfs *buf)
4385 {
4386         struct super_block *sb = dentry->d_sb;
4387         struct ext4_sb_info *sbi = EXT4_SB(sb);
4388         struct ext4_super_block *es = sbi->s_es;
4389         u64 fsid;
4390
4391         if (test_opt(sb, MINIX_DF)) {
4392                 sbi->s_overhead_last = 0;
4393         } else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
4394                 ext4_group_t i, ngroups = ext4_get_groups_count(sb);
4395                 ext4_fsblk_t overhead = 0;
4396
4397                 /*
4398                  * Compute the overhead (FS structures).  This is constant
4399                  * for a given filesystem unless the number of block groups
4400                  * changes so we cache the previous value until it does.
4401                  */
4402
4403                 /*
4404                  * All of the blocks before first_data_block are
4405                  * overhead
4406                  */
4407                 overhead = le32_to_cpu(es->s_first_data_block);
4408
4409                 /*
4410                  * Add the overhead attributed to the superblock and
4411                  * block group descriptors.  If the sparse superblocks
4412                  * feature is turned on, then not all groups have this.
4413                  */
4414                 for (i = 0; i < ngroups; i++) {
4415                         overhead += ext4_bg_has_super(sb, i) +
4416                                 ext4_bg_num_gdb(sb, i);
4417                         cond_resched();
4418                 }
4419
4420                 /*
4421                  * Every block group has an inode bitmap, a block
4422                  * bitmap, and an inode table.
4423                  */
4424                 overhead += ngroups * (2 + sbi->s_itb_per_group);
4425                 sbi->s_overhead_last = overhead;
4426                 smp_wmb();
4427                 sbi->s_blocks_last = ext4_blocks_count(es);
4428         }
4429
4430         buf->f_type = EXT4_SUPER_MAGIC;
4431         buf->f_bsize = sb->s_blocksize;
4432         buf->f_blocks = ext4_blocks_count(es) - sbi->s_overhead_last;
4433         buf->f_bfree = percpu_counter_sum_positive(&sbi->s_freeblocks_counter) -
4434                        percpu_counter_sum_positive(&sbi->s_dirtyblocks_counter);
4435         buf->f_bavail = buf->f_bfree - ext4_r_blocks_count(es);
4436         if (buf->f_bfree < ext4_r_blocks_count(es))
4437                 buf->f_bavail = 0;
4438         buf->f_files = le32_to_cpu(es->s_inodes_count);
4439         buf->f_ffree = percpu_counter_sum_positive(&sbi->s_freeinodes_counter);
4440         buf->f_namelen = EXT4_NAME_LEN;
4441         fsid = le64_to_cpup((void *)es->s_uuid) ^
4442                le64_to_cpup((void *)es->s_uuid + sizeof(u64));
4443         buf->f_fsid.val[0] = fsid & 0xFFFFFFFFUL;
4444         buf->f_fsid.val[1] = (fsid >> 32) & 0xFFFFFFFFUL;
4445
4446         return 0;
4447 }
4448
4449 /* Helper function for writing quotas on sync - we need to start transaction
4450  * before quota file is locked for write. Otherwise the are possible deadlocks:
4451  * Process 1                         Process 2
4452  * ext4_create()                     quota_sync()
4453  *   jbd2_journal_start()                  write_dquot()
4454  *   dquot_initialize()                         down(dqio_mutex)
4455  *     down(dqio_mutex)                    jbd2_journal_start()
4456  *
4457  */
4458
4459 #ifdef CONFIG_QUOTA
4460
4461 static inline struct inode *dquot_to_inode(struct dquot *dquot)
4462 {
4463         return sb_dqopt(dquot->dq_sb)->files[dquot->dq_type];
4464 }
4465
4466 static int ext4_write_dquot(struct dquot *dquot)
4467 {
4468         int ret, err;
4469         handle_t *handle;
4470         struct inode *inode;
4471
4472         inode = dquot_to_inode(dquot);
4473         handle = ext4_journal_start(inode,
4474                                     EXT4_QUOTA_TRANS_BLOCKS(dquot->dq_sb));
4475         if (IS_ERR(handle))
4476                 return PTR_ERR(handle);
4477         ret = dquot_commit(dquot);
4478         err = ext4_journal_stop(handle);
4479         if (!ret)
4480                 ret = err;
4481         return ret;
4482 }
4483
4484 static int ext4_acquire_dquot(struct dquot *dquot)
4485 {
4486         int ret, err;
4487         handle_t *handle;
4488
4489         handle = ext4_journal_start(dquot_to_inode(dquot),
4490                                     EXT4_QUOTA_INIT_BLOCKS(dquot->dq_sb));
4491         if (IS_ERR(handle))
4492                 return PTR_ERR(handle);
4493         ret = dquot_acquire(dquot);
4494         err = ext4_journal_stop(handle);
4495         if (!ret)
4496                 ret = err;
4497         return ret;
4498 }
4499
4500 static int ext4_release_dquot(struct dquot *dquot)
4501 {
4502         int ret, err;
4503         handle_t *handle;
4504
4505         handle = ext4_journal_start(dquot_to_inode(dquot),
4506                                     EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
4507         if (IS_ERR(handle)) {
4508                 /* Release dquot anyway to avoid endless cycle in dqput() */
4509                 dquot_release(dquot);
4510                 return PTR_ERR(handle);
4511         }
4512         ret = dquot_release(dquot);
4513         err = ext4_journal_stop(handle);
4514         if (!ret)
4515                 ret = err;
4516         return ret;
4517 }
4518
4519 static int ext4_mark_dquot_dirty(struct dquot *dquot)
4520 {
4521         /* Are we journaling quotas? */
4522         if (EXT4_SB(dquot->dq_sb)->s_qf_names[USRQUOTA] ||
4523             EXT4_SB(dquot->dq_sb)->s_qf_names[GRPQUOTA]) {
4524                 dquot_mark_dquot_dirty(dquot);
4525                 return ext4_write_dquot(dquot);
4526         } else {
4527                 return dquot_mark_dquot_dirty(dquot);
4528         }
4529 }
4530
4531 static int ext4_write_info(struct super_block *sb, int type)
4532 {
4533         int ret, err;
4534         handle_t *handle;
4535
4536         /* Data block + inode block */
4537         handle = ext4_journal_start(sb->s_root->d_inode, 2);
4538         if (IS_ERR(handle))
4539                 return PTR_ERR(handle);
4540         ret = dquot_commit_info(sb, type);
4541         err = ext4_journal_stop(handle);
4542         if (!ret)
4543                 ret = err;
4544         return ret;
4545 }
4546
4547 /*
4548  * Turn on quotas during mount time - we need to find
4549  * the quota file and such...
4550  */
4551 static int ext4_quota_on_mount(struct super_block *sb, int type)
4552 {
4553         return dquot_quota_on_mount(sb, EXT4_SB(sb)->s_qf_names[type],
4554                                         EXT4_SB(sb)->s_jquota_fmt, type);
4555 }
4556
4557 /*
4558  * Standard function to be called on quota_on
4559  */
4560 static int ext4_quota_on(struct super_block *sb, int type, int format_id,
4561                          char *name)
4562 {
4563         int err;
4564         struct path path;
4565
4566         if (!test_opt(sb, QUOTA))
4567                 return -EINVAL;
4568
4569         err = kern_path(name, LOOKUP_FOLLOW, &path);
4570         if (err)
4571                 return err;
4572
4573         /* Quotafile not on the same filesystem? */
4574         if (path.mnt->mnt_sb != sb) {
4575                 path_put(&path);
4576                 return -EXDEV;
4577         }
4578         /* Journaling quota? */
4579         if (EXT4_SB(sb)->s_qf_names[type]) {
4580                 /* Quotafile not in fs root? */
4581                 if (path.dentry->d_parent != sb->s_root)
4582                         ext4_msg(sb, KERN_WARNING,
4583                                 "Quota file not on filesystem root. "
4584                                 "Journaled quota will not work");
4585         }
4586
4587         /*
4588          * When we journal data on quota file, we have to flush journal to see
4589          * all updates to the file when we bypass pagecache...
4590          */
4591         if (EXT4_SB(sb)->s_journal &&
4592             ext4_should_journal_data(path.dentry->d_inode)) {
4593                 /*
4594                  * We don't need to lock updates but journal_flush() could
4595                  * otherwise be livelocked...
4596                  */
4597                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
4598                 err = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
4599                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
4600                 if (err) {
4601                         path_put(&path);
4602                         return err;
4603                 }
4604         }
4605
4606         err = dquot_quota_on_path(sb, type, format_id, &path);
4607         path_put(&path);
4608         return err;
4609 }
4610
4611 static int ext4_quota_off(struct super_block *sb, int type)
4612 {
4613         /* Force all delayed allocation blocks to be allocated.
4614          * Caller already holds s_umount sem */
4615         if (test_opt(sb, DELALLOC))
4616                 sync_filesystem(sb);
4617
4618         return dquot_quota_off(sb, type);
4619 }
4620
4621 /* Read data from quotafile - avoid pagecache and such because we cannot afford
4622  * acquiring the locks... As quota files are never truncated and quota code
4623  * itself serializes the operations (and noone else should touch the files)
4624  * we don't have to be afraid of races */
4625 static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
4626                                size_t len, loff_t off)
4627 {
4628         struct inode *inode = sb_dqopt(sb)->files[type];
4629         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4630         int err = 0;
4631         int offset = off & (sb->s_blocksize - 1);
4632         int tocopy;
4633         size_t toread;
4634         struct buffer_head *bh;
4635         loff_t i_size = i_size_read(inode);
4636
4637         if (off > i_size)
4638                 return 0;
4639         if (off+len > i_size)
4640                 len = i_size-off;
4641         toread = len;
4642         while (toread > 0) {
4643                 tocopy = sb->s_blocksize - offset < toread ?
4644                                 sb->s_blocksize - offset : toread;
4645                 bh = ext4_bread(NULL, inode, blk, 0, &err);
4646                 if (err)
4647                         return err;
4648                 if (!bh)        /* A hole? */
4649                         memset(data, 0, tocopy);
4650                 else
4651                         memcpy(data, bh->b_data+offset, tocopy);
4652                 brelse(bh);
4653                 offset = 0;
4654                 toread -= tocopy;
4655                 data += tocopy;
4656                 blk++;
4657         }
4658         return len;
4659 }
4660
4661 /* Write to quotafile (we know the transaction is already started and has
4662  * enough credits) */
4663 static ssize_t ext4_quota_write(struct super_block *sb, int type,
4664                                 const char *data, size_t len, loff_t off)
4665 {
4666         struct inode *inode = sb_dqopt(sb)->files[type];
4667         ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
4668         int err = 0;
4669         int offset = off & (sb->s_blocksize - 1);
4670         struct buffer_head *bh;
4671         handle_t *handle = journal_current_handle();
4672
4673         if (EXT4_SB(sb)->s_journal && !handle) {
4674                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4675                         " cancelled because transaction is not started",
4676                         (unsigned long long)off, (unsigned long long)len);
4677                 return -EIO;
4678         }
4679         /*
4680          * Since we account only one data block in transaction credits,
4681          * then it is impossible to cross a block boundary.
4682          */
4683         if (sb->s_blocksize - offset < len) {
4684                 ext4_msg(sb, KERN_WARNING, "Quota write (off=%llu, len=%llu)"
4685                         " cancelled because not block aligned",
4686                         (unsigned long long)off, (unsigned long long)len);
4687                 return -EIO;
4688         }
4689
4690         mutex_lock_nested(&inode->i_mutex, I_MUTEX_QUOTA);
4691         bh = ext4_bread(handle, inode, blk, 1, &err);
4692         if (!bh)
4693                 goto out;
4694         err = ext4_journal_get_write_access(handle, bh);
4695         if (err) {
4696                 brelse(bh);
4697                 goto out;
4698         }
4699         lock_buffer(bh);
4700         memcpy(bh->b_data+offset, data, len);
4701         flush_dcache_page(bh->b_page);
4702         unlock_buffer(bh);
4703         err = ext4_handle_dirty_metadata(handle, NULL, bh);
4704         brelse(bh);
4705 out:
4706         if (err) {
4707                 mutex_unlock(&inode->i_mutex);
4708                 return err;
4709         }
4710         if (inode->i_size < off + len) {
4711                 i_size_write(inode, off + len);
4712                 EXT4_I(inode)->i_disksize = inode->i_size;
4713         }
4714         inode->i_mtime = inode->i_ctime = CURRENT_TIME;
4715         ext4_mark_inode_dirty(handle, inode);
4716         mutex_unlock(&inode->i_mutex);
4717         return len;
4718 }
4719
4720 #endif
4721
4722 static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
4723                        const char *dev_name, void *data)
4724 {
4725         return mount_bdev(fs_type, flags, dev_name, data, ext4_fill_super);
4726 }
4727
4728 #if !defined(CONFIG_EXT2_FS) && !defined(CONFIG_EXT2_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4729 static struct file_system_type ext2_fs_type = {
4730         .owner          = THIS_MODULE,
4731         .name           = "ext2",
4732         .mount          = ext4_mount,
4733         .kill_sb        = kill_block_super,
4734         .fs_flags       = FS_REQUIRES_DEV,
4735 };
4736
4737 static inline void register_as_ext2(void)
4738 {
4739         int err = register_filesystem(&ext2_fs_type);
4740         if (err)
4741                 printk(KERN_WARNING
4742                        "EXT4-fs: Unable to register as ext2 (%d)\n", err);
4743 }
4744
4745 static inline void unregister_as_ext2(void)
4746 {
4747         unregister_filesystem(&ext2_fs_type);
4748 }
4749 MODULE_ALIAS("ext2");
4750 #else
4751 static inline void register_as_ext2(void) { }
4752 static inline void unregister_as_ext2(void) { }
4753 #endif
4754
4755 #if !defined(CONFIG_EXT3_FS) && !defined(CONFIG_EXT3_FS_MODULE) && defined(CONFIG_EXT4_USE_FOR_EXT23)
4756 static inline void register_as_ext3(void)
4757 {
4758         int err = register_filesystem(&ext3_fs_type);
4759         if (err)
4760                 printk(KERN_WARNING
4761                        "EXT4-fs: Unable to register as ext3 (%d)\n", err);
4762 }
4763
4764 static inline void unregister_as_ext3(void)
4765 {
4766         unregister_filesystem(&ext3_fs_type);
4767 }
4768 MODULE_ALIAS("ext3");
4769 #else
4770 static inline void register_as_ext3(void) { }
4771 static inline void unregister_as_ext3(void) { }
4772 #endif
4773
4774 static struct file_system_type ext4_fs_type = {
4775         .owner          = THIS_MODULE,
4776         .name           = "ext4",
4777         .mount          = ext4_mount,
4778         .kill_sb        = kill_block_super,
4779         .fs_flags       = FS_REQUIRES_DEV,
4780 };
4781
4782 int __init ext4_init_feat_adverts(void)
4783 {
4784         struct ext4_features *ef;
4785         int ret = -ENOMEM;
4786
4787         ef = kzalloc(sizeof(struct ext4_features), GFP_KERNEL);
4788         if (!ef)
4789                 goto out;
4790
4791         ef->f_kobj.kset = ext4_kset;
4792         init_completion(&ef->f_kobj_unregister);
4793         ret = kobject_init_and_add(&ef->f_kobj, &ext4_feat_ktype, NULL,
4794                                    "features");
4795         if (ret) {
4796                 kfree(ef);
4797                 goto out;
4798         }
4799
4800         ext4_feat = ef;
4801         ret = 0;
4802 out:
4803         return ret;
4804 }
4805
4806 static int __init ext4_init_fs(void)
4807 {
4808         int err;
4809
4810         ext4_check_flag_values();
4811         err = ext4_init_pageio();
4812         if (err)
4813                 return err;
4814         err = ext4_init_system_zone();
4815         if (err)
4816                 goto out5;
4817         ext4_kset = kset_create_and_add("ext4", NULL, fs_kobj);
4818         if (!ext4_kset)
4819                 goto out4;
4820         ext4_proc_root = proc_mkdir("fs/ext4", NULL);
4821
4822         err = ext4_init_feat_adverts();
4823
4824         err = ext4_init_mballoc();
4825         if (err)
4826                 goto out3;
4827
4828         err = ext4_init_xattr();
4829         if (err)
4830                 goto out2;
4831         err = init_inodecache();
4832         if (err)
4833                 goto out1;
4834         register_as_ext2();
4835         register_as_ext3();
4836         err = register_filesystem(&ext4_fs_type);
4837         if (err)
4838                 goto out;
4839
4840         ext4_li_info = NULL;
4841         mutex_init(&ext4_li_mtx);
4842         return 0;
4843 out:
4844         unregister_as_ext2();
4845         unregister_as_ext3();
4846         destroy_inodecache();
4847 out1:
4848         ext4_exit_xattr();
4849 out2:
4850         ext4_exit_mballoc();
4851 out3:
4852         kfree(ext4_feat);
4853         remove_proc_entry("fs/ext4", NULL);
4854         kset_unregister(ext4_kset);
4855 out4:
4856         ext4_exit_system_zone();
4857 out5:
4858         ext4_exit_pageio();
4859         return err;
4860 }
4861
4862 static void __exit ext4_exit_fs(void)
4863 {
4864         ext4_destroy_lazyinit_thread();
4865         unregister_as_ext2();
4866         unregister_as_ext3();
4867         unregister_filesystem(&ext4_fs_type);
4868         destroy_inodecache();
4869         ext4_exit_xattr();
4870         ext4_exit_mballoc();
4871         remove_proc_entry("fs/ext4", NULL);
4872         kset_unregister(ext4_kset);
4873         ext4_exit_system_zone();
4874         ext4_exit_pageio();
4875 }
4876
4877 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
4878 MODULE_DESCRIPTION("Fourth Extended Filesystem");
4879 MODULE_LICENSE("GPL");
4880 module_init(ext4_init_fs)
4881 module_exit(ext4_exit_fs)