drivers/staging/rdma/ipath/ipath_fs.c

   1 /*
   2  * Copyright (c) 2006, 2007 QLogic Corporation. All rights reserved.
   3  * Copyright (c) 2006 PathScale, Inc. All rights reserved.
   4  *
   5  * This software is available to you under a choice of one of two
   6  * licenses.  You may choose to be licensed under the terms of the GNU
   7  * General Public License (GPL) Version 2, available from the file
   8  * COPYING in the main directory of this source tree, or the
   9  * OpenIB.org BSD license below:
  10  *
  11  *     Redistribution and use in source and binary forms, with or
  12  *     without modification, are permitted provided that the following
  13  *     conditions are met:
  14  *
  15  *      - Redistributions of source code must retain the above
  16  *        copyright notice, this list of conditions and the following
  17  *        disclaimer.
  18  *
  19  *      - Redistributions in binary form must reproduce the above
  20  *        copyright notice, this list of conditions and the following
  21  *        disclaimer in the documentation and/or other materials
  22  *        provided with the distribution.
  23  *
  24  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  28  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  29  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  30  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  31  * SOFTWARE.
  32  */
  33
  34 #include <linux/module.h>
  35 #include <linux/fs.h>
  36 #include <linux/mount.h>
  37 #include <linux/pagemap.h>
  38 #include <linux/init.h>
  39 #include <linux/namei.h>
  40 #include <linux/slab.h>
  41
  42 #include "ipath_kernel.h"
  43
  44 #define IPATHFS_MAGIC 0x726a77
  45
  46 static struct super_block *ipath_super;
  47
  48 static int ipathfs_mknod(struct inode *dir, struct dentry *dentry,
  49                          umode_t mode, const struct file_operations *fops,
  50                          void *data)
  51 {
  52         int error;
  53         struct inode *inode = new_inode(dir->i_sb);
  54
  55         if (!inode) {
  56                 error = -EPERM;
  57                 goto bail;
  58         }
  59
  60         inode->i_ino = get_next_ino();
  61         inode->i_mode = mode;
  62         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
  63         inode->i_private = data;
  64         if (S_ISDIR(mode)) {
  65                 inode->i_op = &simple_dir_inode_operations;
  66                 inc_nlink(inode);
  67                 inc_nlink(dir);
  68         }
  69
  70         inode->i_fop = fops;
  71
  72         d_instantiate(dentry, inode);
  73         error = 0;
  74
  75 bail:
  76         return error;
  77 }
  78
  79 static int create_file(const char *name, umode_t mode,
  80                        struct dentry *parent, struct dentry **dentry,
  81                        const struct file_operations *fops, void *data)
  82 {
  83         int error;
  84
  85         inode_lock(d_inode(parent));
  86         *dentry = lookup_one_len(name, parent, strlen(name));
  87         if (!IS_ERR(*dentry))
  88                 error = ipathfs_mknod(d_inode(parent), *dentry,
  89                                       mode, fops, data);
  90         else
  91                 error = PTR_ERR(*dentry);
  92         inode_unlock(d_inode(parent));
  93
  94         return error;
  95 }
  96
  97 static ssize_t atomic_stats_read(struct file *file, char __user *buf,
  98                                  size_t count, loff_t *ppos)
  99 {
 100         return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
 101                                        sizeof ipath_stats);
 102 }
 103
 104 static const struct file_operations atomic_stats_ops = {
 105         .read = atomic_stats_read,
 106         .llseek = default_llseek,
 107 };
 108
 109 static ssize_t atomic_counters_read(struct file *file, char __user *buf,
 110                                     size_t count, loff_t *ppos)
 111 {
 112         struct infinipath_counters counters;
 113         struct ipath_devdata *dd;
 114
 115         dd = file_inode(file)->i_private;
 116         dd->ipath_f_read_counters(dd, &counters);
 117
 118         return simple_read_from_buffer(buf, count, ppos, &counters,
 119                                        sizeof counters);
 120 }
 121
 122 static const struct file_operations atomic_counters_ops = {
 123         .read = atomic_counters_read,
 124         .llseek = default_llseek,
 125 };
 126
 127 static ssize_t flash_read(struct file *file, char __user *buf,
 128                           size_t count, loff_t *ppos)
 129 {
 130         struct ipath_devdata *dd;
 131         ssize_t ret;
 132         loff_t pos;
 133         char *tmp;
 134
 135         pos = *ppos;
 136
 137         if ( pos < 0) {
 138                 ret = -EINVAL;
 139                 goto bail;
 140         }
 141
 142         if (pos >= sizeof(struct ipath_flash)) {
 143                 ret = 0;
 144                 goto bail;
 145         }
 146
 147         if (count > sizeof(struct ipath_flash) - pos)
 148                 count = sizeof(struct ipath_flash) - pos;
 149
 150         tmp = kmalloc(count, GFP_KERNEL);
 151         if (!tmp) {
 152                 ret = -ENOMEM;
 153                 goto bail;
 154         }
 155
 156         dd = file_inode(file)->i_private;
 157         if (ipath_eeprom_read(dd, pos, tmp, count)) {
 158                 ipath_dev_err(dd, "failed to read from flash\n");
 159                 ret = -ENXIO;
 160                 goto bail_tmp;
 161         }
 162
 163         if (copy_to_user(buf, tmp, count)) {
 164                 ret = -EFAULT;
 165                 goto bail_tmp;
 166         }
 167
 168         *ppos = pos + count;
 169         ret = count;
 170
 171 bail_tmp:
 172         kfree(tmp);
 173
 174 bail:
 175         return ret;
 176 }
 177
 178 static ssize_t flash_write(struct file *file, const char __user *buf,
 179                            size_t count, loff_t *ppos)
 180 {
 181         struct ipath_devdata *dd;
 182         ssize_t ret;
 183         loff_t pos;
 184         char *tmp;
 185
 186         pos = *ppos;
 187
 188         if (pos != 0) {
 189                 ret = -EINVAL;
 190                 goto bail;
 191         }
 192
 193         if (count != sizeof(struct ipath_flash)) {
 194                 ret = -EINVAL;
 195                 goto bail;
 196         }
 197
 198         tmp = memdup_user(buf, count);
 199         if (IS_ERR(tmp))
 200                 return PTR_ERR(tmp);
 201
 202         dd = file_inode(file)->i_private;
 203         if (ipath_eeprom_write(dd, pos, tmp, count)) {
 204                 ret = -ENXIO;
 205                 ipath_dev_err(dd, "failed to write to flash\n");
 206                 goto bail_tmp;
 207         }
 208
 209         *ppos = pos + count;
 210         ret = count;
 211
 212 bail_tmp:
 213         kfree(tmp);
 214
 215 bail:
 216         return ret;
 217 }
 218
 219 static const struct file_operations flash_ops = {
 220         .read = flash_read,
 221         .write = flash_write,
 222         .llseek = default_llseek,
 223 };
 224
 225 static int create_device_files(struct super_block *sb,
 226                                struct ipath_devdata *dd)
 227 {
 228         struct dentry *dir, *tmp;
 229         char unit[10];
 230         int ret;
 231
 232         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 233         ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
 234                           &simple_dir_operations, dd);
 235         if (ret) {
 236                 printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
 237                 goto bail;
 238         }
 239
 240         ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
 241                           &atomic_counters_ops, dd);
 242         if (ret) {
 243                 printk(KERN_ERR "create_file(%s/atomic_counters) "
 244                        "failed: %d\n", unit, ret);
 245                 goto bail;
 246         }
 247
 248         ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
 249                           &flash_ops, dd);
 250         if (ret) {
 251                 printk(KERN_ERR "create_file(%s/flash) "
 252                        "failed: %d\n", unit, ret);
 253                 goto bail;
 254         }
 255
 256 bail:
 257         return ret;
 258 }
 259
 260 static int remove_file(struct dentry *parent, char *name)
 261 {
 262         struct dentry *tmp;
 263         int ret;
 264
 265         tmp = lookup_one_len(name, parent, strlen(name));
 266
 267         if (IS_ERR(tmp)) {
 268                 ret = PTR_ERR(tmp);
 269                 goto bail;
 270         }
 271
 272         spin_lock(&tmp->d_lock);
 273         if (simple_positive(tmp)) {
 274                 dget_dlock(tmp);
 275                 __d_drop(tmp);
 276                 spin_unlock(&tmp->d_lock);
 277                 simple_unlink(d_inode(parent), tmp);
 278         } else
 279                 spin_unlock(&tmp->d_lock);
 280
 281         ret = 0;
 282 bail:
 283         /*
 284          * We don't expect clients to care about the return value, but
 285          * it's there if they need it.
 286          */
 287         return ret;
 288 }
 289
 290 static int remove_device_files(struct super_block *sb,
 291                                struct ipath_devdata *dd)
 292 {
 293         struct dentry *dir, *root;
 294         char unit[10];
 295         int ret;
 296
 297         root = dget(sb->s_root);
 298         inode_lock(d_inode(root));
 299         snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
 300         dir = lookup_one_len(unit, root, strlen(unit));
 301
 302         if (IS_ERR(dir)) {
 303                 ret = PTR_ERR(dir);
 304                 printk(KERN_ERR "Lookup of %s failed\n", unit);
 305                 goto bail;
 306         }
 307
 308         remove_file(dir, "flash");
 309         remove_file(dir, "atomic_counters");
 310         d_delete(dir);
 311         ret = simple_rmdir(d_inode(root), dir);
 312
 313 bail:
 314         inode_unlock(d_inode(root));
 315         dput(root);
 316         return ret;
 317 }
 318
 319 static int ipathfs_fill_super(struct super_block *sb, void *data,
 320                               int silent)
 321 {
 322         struct ipath_devdata *dd, *tmp;
 323         unsigned long flags;
 324         int ret;
 325
 326         static struct tree_descr files[] = {
 327                 [2] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
 328                 {""},
 329         };
 330
 331         ret = simple_fill_super(sb, IPATHFS_MAGIC, files);
 332         if (ret) {
 333                 printk(KERN_ERR "simple_fill_super failed: %d\n", ret);
 334                 goto bail;
 335         }
 336
 337         spin_lock_irqsave(&ipath_devs_lock, flags);
 338
 339         list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
 340                 spin_unlock_irqrestore(&ipath_devs_lock, flags);
 341                 ret = create_device_files(sb, dd);
 342                 if (ret)
 343                         goto bail;
 344                 spin_lock_irqsave(&ipath_devs_lock, flags);
 345         }
 346
 347         spin_unlock_irqrestore(&ipath_devs_lock, flags);
 348
 349 bail:
 350         return ret;
 351 }
 352
 353 static struct dentry *ipathfs_mount(struct file_system_type *fs_type,
 354                         int flags, const char *dev_name, void *data)
 355 {
 356         struct dentry *ret;
 357         ret = mount_single(fs_type, flags, data, ipathfs_fill_super);
 358         if (!IS_ERR(ret))
 359                 ipath_super = ret->d_sb;
 360         return ret;
 361 }
 362
 363 static void ipathfs_kill_super(struct super_block *s)
 364 {
 365         kill_litter_super(s);
 366         ipath_super = NULL;
 367 }
 368
 369 int ipathfs_add_device(struct ipath_devdata *dd)
 370 {
 371         int ret;
 372
 373         if (ipath_super == NULL) {
 374                 ret = 0;
 375                 goto bail;
 376         }
 377
 378         ret = create_device_files(ipath_super, dd);
 379
 380 bail:
 381         return ret;
 382 }
 383
 384 int ipathfs_remove_device(struct ipath_devdata *dd)
 385 {
 386         int ret;
 387
 388         if (ipath_super == NULL) {
 389                 ret = 0;
 390                 goto bail;
 391         }
 392
 393         ret = remove_device_files(ipath_super, dd);
 394
 395 bail:
 396         return ret;
 397 }
 398
 399 static struct file_system_type ipathfs_fs_type = {
 400         .owner =        THIS_MODULE,
 401         .name =         "ipathfs",
 402         .mount =        ipathfs_mount,
 403         .kill_sb =      ipathfs_kill_super,
 404 };
 405 MODULE_ALIAS_FS("ipathfs");
 406
 407 int __init ipath_init_ipathfs(void)
 408 {
 409         return register_filesystem(&ipathfs_fs_type);
 410 }
 411
 412 void __exit ipath_exit_ipathfs(void)
 413 {
 414         unregister_filesystem(&ipathfs_fs_type);
 415 }