drivers/staging/lustre/lustre/lvfs/lvfs_linux.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/lvfs/lvfs_linux.c
  37  *
  38  * Author: Andreas Dilger <adilger@clusterfs.com>
  39  */
  40
  41 #define DEBUG_SUBSYSTEM S_FILTER
  42
  43 #include <linux/fs.h>
  44 #include <asm/unistd.h>
  45 #include <linux/slab.h>
  46 #include <linux/pagemap.h>
  47 #include <linux/quotaops.h>
  48 #include <linux/libcfs/libcfs.h>
  49 #include <linux/module.h>
  50 #include <linux/init.h>
  51 #include <linux/lustre_compat25.h>
  52 #include <lvfs.h>
  53
  54 #include <obd.h>
  55 #include <lustre_lib.h>
  56
  57 struct lprocfs_stats *obd_memory = NULL;
  58 EXPORT_SYMBOL(obd_memory);
  59 /* refine later and change to seqlock or simlar from libcfs */
  60
  61 /* Debugging check only needed during development */
  62 #ifdef OBD_CTXT_DEBUG
  63 # define ASSERT_CTXT_MAGIC(magic) LASSERT((magic) == OBD_RUN_CTXT_MAGIC)
  64 # define ASSERT_NOT_KERNEL_CTXT(msg) LASSERTF(!segment_eq(get_fs(), get_ds()),\
  65                                               msg)
  66 # define ASSERT_KERNEL_CTXT(msg) LASSERTF(segment_eq(get_fs(), get_ds()), msg)
  67 #else
  68 # define ASSERT_CTXT_MAGIC(magic) do {} while (0)
  69 # define ASSERT_NOT_KERNEL_CTXT(msg) do {} while (0)
  70 # define ASSERT_KERNEL_CTXT(msg) do {} while (0)
  71 #endif
  72
  73 static void push_group_info(struct lvfs_run_ctxt *save,
  74                             struct group_info *ginfo)
  75 {
  76         if (!ginfo) {
  77                 save->ngroups = current_ngroups;
  78                 current_ngroups = 0;
  79         } else {
  80                 struct cred *cred;
  81                 task_lock(current);
  82                 save->group_info = current_cred()->group_info;
  83                 cred = prepare_creds();
  84                 if (cred) {
  85                         cred->group_info = ginfo;
  86                         commit_creds(cred);
  87                 }
  88                 task_unlock(current);
  89         }
  90 }
  91
  92 static void pop_group_info(struct lvfs_run_ctxt *save,
  93                            struct group_info *ginfo)
  94 {
  95         if (!ginfo) {
  96                 current_ngroups = save->ngroups;
  97         } else {
  98                 struct cred *cred;
  99                 task_lock(current);
 100                 cred = prepare_creds();
 101                 if (cred) {
 102                         cred->group_info = save->group_info;
 103                         commit_creds(cred);
 104                 }
 105                 task_unlock(current);
 106         }
 107 }
 108
 109 /* push / pop to root of obd store */
 110 void push_ctxt(struct lvfs_run_ctxt *save, struct lvfs_run_ctxt *new_ctx,
 111                struct lvfs_ucred *uc)
 112 {
 113         /* if there is underlaying dt_device then push_ctxt is not needed */
 114         if (new_ctx->dt != NULL)
 115                 return;
 116
 117         /* ASSERT_NOT_KERNEL_CTXT("already in kernel context!\n"); */
 118         ASSERT_CTXT_MAGIC(new_ctx->magic);
 119         OBD_SET_CTXT_MAGIC(save);
 120
 121         save->fs = get_fs();
 122         LASSERT(d_count(cfs_fs_pwd(current->fs)));
 123         LASSERT(d_count(new_ctx->pwd));
 124         save->pwd = dget(cfs_fs_pwd(current->fs));
 125         save->pwdmnt = mntget(cfs_fs_mnt(current->fs));
 126         save->luc.luc_umask = current_umask();
 127         save->ngroups = current_cred()->group_info->ngroups;
 128
 129         LASSERT(save->pwd);
 130         LASSERT(save->pwdmnt);
 131         LASSERT(new_ctx->pwd);
 132         LASSERT(new_ctx->pwdmnt);
 133
 134         if (uc) {
 135                 struct cred *cred;
 136                 save->luc.luc_uid = current_uid();
 137                 save->luc.luc_gid = current_gid();
 138                 save->luc.luc_fsuid = current_fsuid();
 139                 save->luc.luc_fsgid = current_fsgid();
 140                 save->luc.luc_cap = current_cap();
 141
 142                 cred = prepare_creds();
 143                 if (cred) {
 144                         cred->uid = uc->luc_uid;
 145                         cred->gid = uc->luc_gid;
 146                         cred->fsuid = uc->luc_fsuid;
 147                         cred->fsgid = uc->luc_fsgid;
 148                         cred->cap_effective = uc->luc_cap;
 149                         commit_creds(cred);
 150                 }
 151
 152                 push_group_info(save,
 153                                 uc->luc_ginfo ?:
 154                                 uc->luc_identity ? uc->luc_identity->mi_ginfo :
 155                                                    NULL);
 156         }
 157         current->fs->umask = 0; /* umask already applied on client */
 158         set_fs(new_ctx->fs);
 159         ll_set_fs_pwd(current->fs, new_ctx->pwdmnt, new_ctx->pwd);
 160 }
 161 EXPORT_SYMBOL(push_ctxt);
 162
 163 void pop_ctxt(struct lvfs_run_ctxt *saved, struct lvfs_run_ctxt *new_ctx,
 164               struct lvfs_ucred *uc)
 165 {
 166         /* if there is underlaying dt_device then pop_ctxt is not needed */
 167         if (new_ctx->dt != NULL)
 168                 return;
 169
 170         ASSERT_CTXT_MAGIC(saved->magic);
 171         ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
 172
 173         LASSERTF(cfs_fs_pwd(current->fs) == new_ctx->pwd, "%p != %p\n",
 174                  cfs_fs_pwd(current->fs), new_ctx->pwd);
 175         LASSERTF(cfs_fs_mnt(current->fs) == new_ctx->pwdmnt, "%p != %p\n",
 176                  cfs_fs_mnt(current->fs), new_ctx->pwdmnt);
 177
 178         set_fs(saved->fs);
 179         ll_set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 180
 181         dput(saved->pwd);
 182         mntput(saved->pwdmnt);
 183         current->fs->umask = saved->luc.luc_umask;
 184         if (uc) {
 185                 struct cred *cred;
 186                 cred = prepare_creds();
 187                 if (cred) {
 188                         cred->uid = saved->luc.luc_uid;
 189                         cred->gid = saved->luc.luc_gid;
 190                         cred->fsuid = saved->luc.luc_fsuid;
 191                         cred->fsgid = saved->luc.luc_fsgid;
 192                         cred->cap_effective = saved->luc.luc_cap;
 193                         commit_creds(cred);
 194                 }
 195
 196                 pop_group_info(saved,
 197                                uc->luc_ginfo ?:
 198                                uc->luc_identity ? uc->luc_identity->mi_ginfo :
 199                                                   NULL);
 200         }
 201 }
 202 EXPORT_SYMBOL(pop_ctxt);
 203
 204 /* utility to rename a file */
 205 int lustre_rename(struct dentry *dir, struct vfsmount *mnt,
 206                   char *oldname, char *newname)
 207 {
 208         struct dentry *dchild_old, *dchild_new;
 209         int err = 0;
 210
 211         ASSERT_KERNEL_CTXT("kernel doing rename outside kernel context\n");
 212         CDEBUG(D_INODE, "renaming file %.*s to %.*s\n",
 213                (int)strlen(oldname), oldname, (int)strlen(newname), newname);
 214
 215         dchild_old = ll_lookup_one_len(oldname, dir, strlen(oldname));
 216         if (IS_ERR(dchild_old))
 217                 return PTR_ERR(dchild_old);
 218
 219         if (!dchild_old->d_inode)
 220                 GOTO(put_old, err = -ENOENT);
 221
 222         dchild_new = ll_lookup_one_len(newname, dir, strlen(newname));
 223         if (IS_ERR(dchild_new))
 224                 GOTO(put_old, err = PTR_ERR(dchild_new));
 225
 226         err = ll_vfs_rename(dir->d_inode, dchild_old, mnt,
 227                             dir->d_inode, dchild_new, mnt);
 228
 229         dput(dchild_new);
 230 put_old:
 231         dput(dchild_old);
 232         return err;
 233 }
 234 EXPORT_SYMBOL(lustre_rename);
 235
 236 /* Note: dput(dchild) will *not* be called if there is an error */
 237 struct l_file *l_dentry_open(struct lvfs_run_ctxt *ctxt, struct l_dentry *de,
 238                              int flags)
 239 {
 240         struct path path = {
 241                 .dentry = de,
 242                 .mnt = ctxt->pwdmnt,
 243         };
 244         return dentry_open(&path, flags, current_cred());
 245 }
 246 EXPORT_SYMBOL(l_dentry_open);
 247
 248 #ifdef LPROCFS
 249 __s64 lprocfs_read_helper(struct lprocfs_counter *lc,
 250                           struct lprocfs_counter_header *header,
 251                           enum lprocfs_stats_flags flags,
 252                           enum lprocfs_fields_flags field)
 253 {
 254         __s64 ret = 0;
 255
 256         if (lc == NULL || header == NULL)
 257                 return 0;
 258
 259         switch (field) {
 260         case LPROCFS_FIELDS_FLAGS_CONFIG:
 261                 ret = header->lc_config;
 262                 break;
 263         case LPROCFS_FIELDS_FLAGS_SUM:
 264                 ret = lc->lc_sum;
 265                 if ((flags & LPROCFS_STATS_FLAG_IRQ_SAFE) != 0)
 266                         ret += lc->lc_sum_irq;
 267                 break;
 268         case LPROCFS_FIELDS_FLAGS_MIN:
 269                 ret = lc->lc_min;
 270                 break;
 271         case LPROCFS_FIELDS_FLAGS_MAX:
 272                 ret = lc->lc_max;
 273                 break;
 274         case LPROCFS_FIELDS_FLAGS_AVG:
 275                 ret = (lc->lc_max - lc->lc_min) / 2;
 276                 break;
 277         case LPROCFS_FIELDS_FLAGS_SUMSQUARE:
 278                 ret = lc->lc_sumsquare;
 279                 break;
 280         case LPROCFS_FIELDS_FLAGS_COUNT:
 281                 ret = lc->lc_count;
 282                 break;
 283         default:
 284                 break;
 285         }
 286
 287         return ret;
 288 }
 289 EXPORT_SYMBOL(lprocfs_read_helper);
 290 #endif /* LPROCFS */
 291
 292 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 293 MODULE_DESCRIPTION("Lustre VFS Filesystem Helper v0.1");
 294 MODULE_LICENSE("GPL");