fs/afs/inode.c

   1 /*
   2  * Copyright (c) 2002 Red Hat, Inc. All rights reserved.
   3  *
   4  * This software may be freely redistributed under the terms of the
   5  * GNU General Public License.
   6  *
   7  * You should have received a copy of the GNU General Public License
   8  * along with this program; if not, write to the Free Software
   9  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  10  *
  11  * Authors: David Woodhouse <dwmw2@infradead.org>
  12  *          David Howells <dhowells@redhat.com>
  13  *
  14  */
  15
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/fs.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/sched.h>
  22 #include <linux/mount.h>
  23 #include <linux/namei.h>
  24 #include "internal.h"
  25
  26 struct afs_iget_data {
  27         struct afs_fid          fid;
  28         struct afs_volume       *volume;        /* volume on which resides */
  29 };
  30
  31 /*
  32  * map the AFS file status to the inode member variables
  33  */
  34 static int afs_inode_map_status(struct afs_vnode *vnode, struct key *key)
  35 {
  36         struct inode *inode = AFS_VNODE_TO_I(vnode);
  37
  38         _debug("FS: ft=%d lk=%d sz=%llu ver=%Lu mod=%hu",
  39                vnode->status.type,
  40                vnode->status.nlink,
  41                (unsigned long long) vnode->status.size,
  42                vnode->status.data_version,
  43                vnode->status.mode);
  44
  45         switch (vnode->status.type) {
  46         case AFS_FTYPE_FILE:
  47                 inode->i_mode   = S_IFREG | vnode->status.mode;
  48                 inode->i_op     = &afs_file_inode_operations;
  49                 inode->i_fop    = &afs_file_operations;
  50                 break;
  51         case AFS_FTYPE_DIR:
  52                 inode->i_mode   = S_IFDIR | vnode->status.mode;
  53                 inode->i_op     = &afs_dir_inode_operations;
  54                 inode->i_fop    = &afs_dir_file_operations;
  55                 break;
  56         case AFS_FTYPE_SYMLINK:
  57                 /* Symlinks with a mode of 0644 are actually mountpoints. */
  58                 if ((vnode->status.mode & 0777) == 0644) {
  59                         inode->i_flags |= S_AUTOMOUNT;
  60
  61                         spin_lock(&vnode->lock);
  62                         set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
  63                         spin_unlock(&vnode->lock);
  64
  65                         inode->i_mode   = S_IFDIR | 0555;
  66                         inode->i_op     = &afs_mntpt_inode_operations;
  67                         inode->i_fop    = &afs_mntpt_file_operations;
  68                 } else {
  69                         inode->i_mode   = S_IFLNK | vnode->status.mode;
  70                         inode->i_op     = &page_symlink_inode_operations;
  71                 }
  72                 inode_nohighmem(inode);
  73                 break;
  74         default:
  75                 printk("kAFS: AFS vnode with undefined type\n");
  76                 return -EBADMSG;
  77         }
  78
  79 #ifdef CONFIG_AFS_FSCACHE
  80         if (vnode->status.size != inode->i_size)
  81                 fscache_attr_changed(vnode->cache);
  82 #endif
  83
  84         set_nlink(inode, vnode->status.nlink);
  85         inode->i_uid            = vnode->status.owner;
  86         inode->i_gid            = vnode->status.group;
  87         inode->i_size           = vnode->status.size;
  88         inode->i_ctime.tv_sec   = vnode->status.mtime_client;
  89         inode->i_ctime.tv_nsec  = 0;
  90         inode->i_atime          = inode->i_mtime = inode->i_ctime;
  91         inode->i_blocks         = 0;
  92         inode->i_generation     = vnode->fid.unique;
  93         inode->i_version        = vnode->status.data_version;
  94         inode->i_mapping->a_ops = &afs_fs_aops;
  95         return 0;
  96 }
  97
  98 /*
  99  * iget5() comparator
 100  */
 101 static int afs_iget5_test(struct inode *inode, void *opaque)
 102 {
 103         struct afs_iget_data *data = opaque;
 104
 105         return inode->i_ino == data->fid.vnode &&
 106                 inode->i_generation == data->fid.unique;
 107 }
 108
 109 /*
 110  * iget5() comparator for inode created by autocell operations
 111  *
 112  * These pseudo inodes don't match anything.
 113  */
 114 static int afs_iget5_autocell_test(struct inode *inode, void *opaque)
 115 {
 116         return 0;
 117 }
 118
 119 /*
 120  * iget5() inode initialiser
 121  */
 122 static int afs_iget5_set(struct inode *inode, void *opaque)
 123 {
 124         struct afs_iget_data *data = opaque;
 125         struct afs_vnode *vnode = AFS_FS_I(inode);
 126
 127         inode->i_ino = data->fid.vnode;
 128         inode->i_generation = data->fid.unique;
 129         vnode->fid = data->fid;
 130         vnode->volume = data->volume;
 131
 132         return 0;
 133 }
 134
 135 /*
 136  * inode retrieval for autocell
 137  */
 138 struct inode *afs_iget_autocell(struct inode *dir, const char *dev_name,
 139                                 int namesz, struct key *key)
 140 {
 141         struct afs_iget_data data;
 142         struct afs_super_info *as;
 143         struct afs_vnode *vnode;
 144         struct super_block *sb;
 145         struct inode *inode;
 146         static atomic_t afs_autocell_ino;
 147
 148         _enter("{%x:%u},%*.*s,",
 149                AFS_FS_I(dir)->fid.vid, AFS_FS_I(dir)->fid.vnode,
 150                namesz, namesz, dev_name ?: "");
 151
 152         sb = dir->i_sb;
 153         as = sb->s_fs_info;
 154         data.volume = as->volume;
 155         data.fid.vid = as->volume->vid;
 156         data.fid.unique = 0;
 157         data.fid.vnode = 0;
 158
 159         inode = iget5_locked(sb, atomic_inc_return(&afs_autocell_ino),
 160                              afs_iget5_autocell_test, afs_iget5_set,
 161                              &data);
 162         if (!inode) {
 163                 _leave(" = -ENOMEM");
 164                 return ERR_PTR(-ENOMEM);
 165         }
 166
 167         _debug("GOT INODE %p { ino=%lu, vl=%x, vn=%x, u=%x }",
 168                inode, inode->i_ino, data.fid.vid, data.fid.vnode,
 169                data.fid.unique);
 170
 171         vnode = AFS_FS_I(inode);
 172
 173         /* there shouldn't be an existing inode */
 174         BUG_ON(!(inode->i_state & I_NEW));
 175
 176         inode->i_size           = 0;
 177         inode->i_mode           = S_IFDIR | S_IRUGO | S_IXUGO;
 178         inode->i_op             = &afs_autocell_inode_operations;
 179         set_nlink(inode, 2);
 180         inode->i_uid            = GLOBAL_ROOT_UID;
 181         inode->i_gid            = GLOBAL_ROOT_GID;
 182         inode->i_ctime.tv_sec   = get_seconds();
 183         inode->i_ctime.tv_nsec  = 0;
 184         inode->i_atime          = inode->i_mtime = inode->i_ctime;
 185         inode->i_blocks         = 0;
 186         inode->i_version        = 0;
 187         inode->i_generation     = 0;
 188
 189         set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
 190         set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
 191         inode->i_flags |= S_AUTOMOUNT | S_NOATIME;
 192         unlock_new_inode(inode);
 193         _leave(" = %p", inode);
 194         return inode;
 195 }
 196
 197 /*
 198  * inode retrieval
 199  */
 200 struct inode *afs_iget(struct super_block *sb, struct key *key,
 201                        struct afs_fid *fid, struct afs_file_status *status,
 202                        struct afs_callback *cb)
 203 {
 204         struct afs_iget_data data = { .fid = *fid };
 205         struct afs_super_info *as;
 206         struct afs_vnode *vnode;
 207         struct inode *inode;
 208         int ret;
 209
 210         _enter(",{%x:%u.%u},,", fid->vid, fid->vnode, fid->unique);
 211
 212         as = sb->s_fs_info;
 213         data.volume = as->volume;
 214
 215         inode = iget5_locked(sb, fid->vnode, afs_iget5_test, afs_iget5_set,
 216                              &data);
 217         if (!inode) {
 218                 _leave(" = -ENOMEM");
 219                 return ERR_PTR(-ENOMEM);
 220         }
 221
 222         _debug("GOT INODE %p { vl=%x vn=%x, u=%x }",
 223                inode, fid->vid, fid->vnode, fid->unique);
 224
 225         vnode = AFS_FS_I(inode);
 226
 227         /* deal with an existing inode */
 228         if (!(inode->i_state & I_NEW)) {
 229                 _leave(" = %p", inode);
 230                 return inode;
 231         }
 232
 233         if (!status) {
 234                 /* it's a remotely extant inode */
 235                 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
 236                 ret = afs_vnode_fetch_status(vnode, NULL, key);
 237                 if (ret < 0)
 238                         goto bad_inode;
 239         } else {
 240                 /* it's an inode we just created */
 241                 memcpy(&vnode->status, status, sizeof(vnode->status));
 242
 243                 if (!cb) {
 244                         /* it's a symlink we just created (the fileserver
 245                          * didn't give us a callback) */
 246                         vnode->cb_version = 0;
 247                         vnode->cb_expiry = 0;
 248                         vnode->cb_type = 0;
 249                         vnode->cb_expires = ktime_get_real_seconds();
 250                 } else {
 251                         vnode->cb_version = cb->version;
 252                         vnode->cb_expiry = cb->expiry;
 253                         vnode->cb_type = cb->type;
 254                         vnode->cb_expires = vnode->cb_expiry +
 255                                 ktime_get_real_seconds();
 256                 }
 257         }
 258
 259         /* set up caching before mapping the status, as map-status reads the
 260          * first page of symlinks to see if they're really mountpoints */
 261         inode->i_size = vnode->status.size;
 262 #ifdef CONFIG_AFS_FSCACHE
 263         vnode->cache = fscache_acquire_cookie(vnode->volume->cache,
 264                                               &afs_vnode_cache_index_def,
 265                                               vnode, true);
 266 #endif
 267
 268         ret = afs_inode_map_status(vnode, key);
 269         if (ret < 0)
 270                 goto bad_inode;
 271
 272         /* success */
 273         clear_bit(AFS_VNODE_UNSET, &vnode->flags);
 274         inode->i_flags |= S_NOATIME;
 275         unlock_new_inode(inode);
 276         _leave(" = %p [CB { v=%u t=%u }]", inode, vnode->cb_version, vnode->cb_type);
 277         return inode;
 278
 279         /* failure */
 280 bad_inode:
 281 #ifdef CONFIG_AFS_FSCACHE
 282         fscache_relinquish_cookie(vnode->cache, 0);
 283         vnode->cache = NULL;
 284 #endif
 285         iget_failed(inode);
 286         _leave(" = %d [bad]", ret);
 287         return ERR_PTR(ret);
 288 }
 289
 290 /*
 291  * mark the data attached to an inode as obsolete due to a write on the server
 292  * - might also want to ditch all the outstanding writes and dirty pages
 293  */
 294 void afs_zap_data(struct afs_vnode *vnode)
 295 {
 296         _enter("{%x:%u}", vnode->fid.vid, vnode->fid.vnode);
 297
 298         /* nuke all the non-dirty pages that aren't locked, mapped or being
 299          * written back in a regular file and completely discard the pages in a
 300          * directory or symlink */
 301         if (S_ISREG(vnode->vfs_inode.i_mode))
 302                 invalidate_remote_inode(&vnode->vfs_inode);
 303         else
 304                 invalidate_inode_pages2(vnode->vfs_inode.i_mapping);
 305 }
 306
 307 /*
 308  * validate a vnode/inode
 309  * - there are several things we need to check
 310  *   - parent dir data changes (rm, rmdir, rename, mkdir, create, link,
 311  *     symlink)
 312  *   - parent dir metadata changed (security changes)
 313  *   - dentry data changed (write, truncate)
 314  *   - dentry metadata changed (security changes)
 315  */
 316 int afs_validate(struct afs_vnode *vnode, struct key *key)
 317 {
 318         int ret;
 319
 320         _enter("{v={%x:%u} fl=%lx},%x",
 321                vnode->fid.vid, vnode->fid.vnode, vnode->flags,
 322                key_serial(key));
 323
 324         if (vnode->cb_promised &&
 325             !test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags) &&
 326             !test_bit(AFS_VNODE_MODIFIED, &vnode->flags) &&
 327             !test_bit(AFS_VNODE_ZAP_DATA, &vnode->flags)) {
 328                 if (vnode->cb_expires < ktime_get_real_seconds() + 10) {
 329                         _debug("callback expired");
 330                         set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
 331                 } else {
 332                         goto valid;
 333                 }
 334         }
 335
 336         if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
 337                 goto valid;
 338
 339         mutex_lock(&vnode->validate_lock);
 340
 341         /* if the promise has expired, we need to check the server again to get
 342          * a new promise - note that if the (parent) directory's metadata was
 343          * changed then the security may be different and we may no longer have
 344          * access */
 345         if (!vnode->cb_promised ||
 346             test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags)) {
 347                 _debug("not promised");
 348                 ret = afs_vnode_fetch_status(vnode, NULL, key);
 349                 if (ret < 0)
 350                         goto error_unlock;
 351                 _debug("new promise [fl=%lx]", vnode->flags);
 352         }
 353
 354         if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
 355                 _debug("file already deleted");
 356                 ret = -ESTALE;
 357                 goto error_unlock;
 358         }
 359
 360         /* if the vnode's data version number changed then its contents are
 361          * different */
 362         if (test_and_clear_bit(AFS_VNODE_ZAP_DATA, &vnode->flags))
 363                 afs_zap_data(vnode);
 364
 365         clear_bit(AFS_VNODE_MODIFIED, &vnode->flags);
 366         mutex_unlock(&vnode->validate_lock);
 367 valid:
 368         _leave(" = 0");
 369         return 0;
 370
 371 error_unlock:
 372         mutex_unlock(&vnode->validate_lock);
 373         _leave(" = %d", ret);
 374         return ret;
 375 }
 376
 377 /*
 378  * read the attributes of an inode
 379  */
 380 int afs_getattr(const struct path *path, struct kstat *stat,
 381                 u32 request_mask, unsigned int query_flags)
 382 {
 383         struct inode *inode = d_inode(path->dentry);
 384
 385         _enter("{ ino=%lu v=%u }", inode->i_ino, inode->i_generation);
 386
 387         generic_fillattr(inode, stat);
 388         return 0;
 389 }
 390
 391 /*
 392  * discard an AFS inode
 393  */
 394 int afs_drop_inode(struct inode *inode)
 395 {
 396         _enter("");
 397
 398         if (test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(inode)->flags))
 399                 return generic_delete_inode(inode);
 400         else
 401                 return generic_drop_inode(inode);
 402 }
 403
 404 /*
 405  * clear an AFS inode
 406  */
 407 void afs_evict_inode(struct inode *inode)
 408 {
 409         struct afs_permits *permits;
 410         struct afs_vnode *vnode;
 411
 412         vnode = AFS_FS_I(inode);
 413
 414         _enter("{%x:%u.%d} v=%u x=%u t=%u }",
 415                vnode->fid.vid,
 416                vnode->fid.vnode,
 417                vnode->fid.unique,
 418                vnode->cb_version,
 419                vnode->cb_expiry,
 420                vnode->cb_type);
 421
 422         _debug("CLEAR INODE %p", inode);
 423
 424         ASSERTCMP(inode->i_ino, ==, vnode->fid.vnode);
 425
 426         truncate_inode_pages_final(&inode->i_data);
 427         clear_inode(inode);
 428
 429         afs_give_up_callback(vnode);
 430
 431         if (vnode->server) {
 432                 spin_lock(&vnode->server->fs_lock);
 433                 rb_erase(&vnode->server_rb, &vnode->server->fs_vnodes);
 434                 spin_unlock(&vnode->server->fs_lock);
 435                 afs_put_server(vnode->server);
 436                 vnode->server = NULL;
 437         }
 438
 439         ASSERT(list_empty(&vnode->writebacks));
 440         ASSERT(!vnode->cb_promised);
 441
 442 #ifdef CONFIG_AFS_FSCACHE
 443         fscache_relinquish_cookie(vnode->cache, 0);
 444         vnode->cache = NULL;
 445 #endif
 446
 447         mutex_lock(&vnode->permits_lock);
 448         permits = vnode->permits;
 449         RCU_INIT_POINTER(vnode->permits, NULL);
 450         mutex_unlock(&vnode->permits_lock);
 451         if (permits)
 452                 call_rcu(&permits->rcu, afs_zap_permits);
 453
 454         _leave("");
 455 }
 456
 457 /*
 458  * set the attributes of an inode
 459  */
 460 int afs_setattr(struct dentry *dentry, struct iattr *attr)
 461 {
 462         struct afs_vnode *vnode = AFS_FS_I(d_inode(dentry));
 463         struct key *key;
 464         int ret;
 465
 466         _enter("{%x:%u},{n=%pd},%x",
 467                vnode->fid.vid, vnode->fid.vnode, dentry,
 468                attr->ia_valid);
 469
 470         if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID |
 471                                 ATTR_MTIME))) {
 472                 _leave(" = 0 [unsupported]");
 473                 return 0;
 474         }
 475
 476         /* flush any dirty data outstanding on a regular file */
 477         if (S_ISREG(vnode->vfs_inode.i_mode)) {
 478                 filemap_write_and_wait(vnode->vfs_inode.i_mapping);
 479                 afs_writeback_all(vnode);
 480         }
 481
 482         if (attr->ia_valid & ATTR_FILE) {
 483                 key = attr->ia_file->private_data;
 484         } else {
 485                 key = afs_request_key(vnode->volume->cell);
 486                 if (IS_ERR(key)) {
 487                         ret = PTR_ERR(key);
 488                         goto error;
 489                 }
 490         }
 491
 492         ret = afs_vnode_setattr(vnode, key, attr);
 493         if (!(attr->ia_valid & ATTR_FILE))
 494                 key_put(key);
 495
 496 error:
 497         _leave(" = %d", ret);
 498         return ret;
 499 }