fs/9p/vfs_inode.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * This file contains vfs inode ops for the 9P2000 protocol.
   4  *
   5  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   6  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #include <linux/module.h>
  12 #include <linux/errno.h>
  13 #include <linux/fs.h>
  14 #include <linux/file.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/stat.h>
  17 #include <linux/string.h>
  18 #include <linux/namei.h>
  19 #include <linux/sched.h>
  20 #include <linux/slab.h>
  21 #include <linux/xattr.h>
  22 #include <linux/posix_acl.h>
  23 #include <net/9p/9p.h>
  24 #include <net/9p/client.h>
  25
  26 #include "v9fs.h"
  27 #include "v9fs_vfs.h"
  28 #include "fid.h"
  29 #include "cache.h"
  30 #include "xattr.h"
  31 #include "acl.h"
  32
  33 static const struct inode_operations v9fs_dir_inode_operations;
  34 static const struct inode_operations v9fs_dir_inode_operations_dotu;
  35 static const struct inode_operations v9fs_file_inode_operations;
  36 static const struct inode_operations v9fs_symlink_inode_operations;
  37
  38 /**
  39  * unixmode2p9mode - convert unix mode bits to plan 9
  40  * @v9ses: v9fs session information
  41  * @mode: mode to convert
  42  *
  43  */
  44
  45 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
  46 {
  47         int res;
  48
  49         res = mode & 0777;
  50         if (S_ISDIR(mode))
  51                 res |= P9_DMDIR;
  52         if (v9fs_proto_dotu(v9ses)) {
  53                 if (v9ses->nodev == 0) {
  54                         if (S_ISSOCK(mode))
  55                                 res |= P9_DMSOCKET;
  56                         if (S_ISFIFO(mode))
  57                                 res |= P9_DMNAMEDPIPE;
  58                         if (S_ISBLK(mode))
  59                                 res |= P9_DMDEVICE;
  60                         if (S_ISCHR(mode))
  61                                 res |= P9_DMDEVICE;
  62                 }
  63
  64                 if ((mode & S_ISUID) == S_ISUID)
  65                         res |= P9_DMSETUID;
  66                 if ((mode & S_ISGID) == S_ISGID)
  67                         res |= P9_DMSETGID;
  68                 if ((mode & S_ISVTX) == S_ISVTX)
  69                         res |= P9_DMSETVTX;
  70         }
  71         return res;
  72 }
  73
  74 /**
  75  * p9mode2perm- convert plan9 mode bits to unix permission bits
  76  * @v9ses: v9fs session information
  77  * @stat: p9_wstat from which mode need to be derived
  78  *
  79  */
  80 static int p9mode2perm(struct v9fs_session_info *v9ses,
  81                        struct p9_wstat *stat)
  82 {
  83         int res;
  84         int mode = stat->mode;
  85
  86         res = mode & 0777; /* S_IRWXUGO */
  87         if (v9fs_proto_dotu(v9ses)) {
  88                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
  89                         res |= S_ISUID;
  90
  91                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
  92                         res |= S_ISGID;
  93
  94                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
  95                         res |= S_ISVTX;
  96         }
  97         return res;
  98 }
  99
 100 /**
 101  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
 102  * @v9ses: v9fs session information
 103  * @stat: p9_wstat from which mode need to be derived
 104  * @rdev: major number, minor number in case of device files.
 105  *
 106  */
 107 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
 108                                struct p9_wstat *stat, dev_t *rdev)
 109 {
 110         int res, r;
 111         u32 mode = stat->mode;
 112
 113         *rdev = 0;
 114         res = p9mode2perm(v9ses, stat);
 115
 116         if ((mode & P9_DMDIR) == P9_DMDIR)
 117                 res |= S_IFDIR;
 118         else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 119                 res |= S_IFLNK;
 120         else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 121                  && (v9ses->nodev == 0))
 122                 res |= S_IFSOCK;
 123         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 124                  && (v9ses->nodev == 0))
 125                 res |= S_IFIFO;
 126         else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 127                  && (v9ses->nodev == 0)) {
 128                 char type = 0;
 129                 int major = -1, minor = -1;
 130
 131                 r = sscanf(stat->extension, "%c %i %i", &type, &major, &minor);
 132                 if (r != 3) {
 133                         p9_debug(P9_DEBUG_ERROR,
 134                                  "invalid device string, umode will be bogus: %s\n",
 135                                  stat->extension);
 136                         return res;
 137                 }
 138                 switch (type) {
 139                 case 'c':
 140                         res |= S_IFCHR;
 141                         break;
 142                 case 'b':
 143                         res |= S_IFBLK;
 144                         break;
 145                 default:
 146                         p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
 147                                  type, stat->extension);
 148                 }
 149                 *rdev = MKDEV(major, minor);
 150         } else
 151                 res |= S_IFREG;
 152
 153         return res;
 154 }
 155
 156 /**
 157  * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 158  * @uflags: flags to convert
 159  * @extended: if .u extensions are active
 160  */
 161
 162 int v9fs_uflags2omode(int uflags, int extended)
 163 {
 164         int ret;
 165
 166         switch (uflags&3) {
 167         default:
 168         case O_RDONLY:
 169                 ret = P9_OREAD;
 170                 break;
 171
 172         case O_WRONLY:
 173                 ret = P9_OWRITE;
 174                 break;
 175
 176         case O_RDWR:
 177                 ret = P9_ORDWR;
 178                 break;
 179         }
 180
 181         if (uflags & O_TRUNC)
 182                 ret |= P9_OTRUNC;
 183
 184         if (extended) {
 185                 if (uflags & O_EXCL)
 186                         ret |= P9_OEXCL;
 187
 188                 if (uflags & O_APPEND)
 189                         ret |= P9_OAPPEND;
 190         }
 191
 192         return ret;
 193 }
 194
 195 /**
 196  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 197  * @wstat: structure to initialize
 198  *
 199  */
 200
 201 void
 202 v9fs_blank_wstat(struct p9_wstat *wstat)
 203 {
 204         wstat->type = ~0;
 205         wstat->dev = ~0;
 206         wstat->qid.type = ~0;
 207         wstat->qid.version = ~0;
 208         *((long long *)&wstat->qid.path) = ~0;
 209         wstat->mode = ~0;
 210         wstat->atime = ~0;
 211         wstat->mtime = ~0;
 212         wstat->length = ~0;
 213         wstat->name = NULL;
 214         wstat->uid = NULL;
 215         wstat->gid = NULL;
 216         wstat->muid = NULL;
 217         wstat->n_uid = INVALID_UID;
 218         wstat->n_gid = INVALID_GID;
 219         wstat->n_muid = INVALID_UID;
 220         wstat->extension = NULL;
 221 }
 222
 223 /**
 224  * v9fs_alloc_inode - helper function to allocate an inode
 225  * @sb: The superblock to allocate the inode from
 226  */
 227 struct inode *v9fs_alloc_inode(struct super_block *sb)
 228 {
 229         struct v9fs_inode *v9inode;
 230
 231         v9inode = alloc_inode_sb(sb, v9fs_inode_cache, GFP_KERNEL);
 232         if (!v9inode)
 233                 return NULL;
 234         v9inode->cache_validity = 0;
 235         mutex_init(&v9inode->v_mutex);
 236         return &v9inode->netfs.inode;
 237 }
 238
 239 /**
 240  * v9fs_free_inode - destroy an inode
 241  * @inode: The inode to be freed
 242  */
 243
 244 void v9fs_free_inode(struct inode *inode)
 245 {
 246         kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 247 }
 248
 249 /*
 250  * Set parameters for the netfs library
 251  */
 252 void v9fs_set_netfs_context(struct inode *inode)
 253 {
 254         struct v9fs_inode *v9inode = V9FS_I(inode);
 255         netfs_inode_init(&v9inode->netfs, &v9fs_req_ops, true);
 256 }
 257
 258 int v9fs_init_inode(struct v9fs_session_info *v9ses,
 259                     struct inode *inode, struct p9_qid *qid, umode_t mode, dev_t rdev)
 260 {
 261         int err = 0;
 262         struct v9fs_inode *v9inode = V9FS_I(inode);
 263
 264         memcpy(&v9inode->qid, qid, sizeof(struct p9_qid));
 265
 266         inode_init_owner(&nop_mnt_idmap, inode, NULL, mode);
 267         inode->i_blocks = 0;
 268         inode->i_rdev = rdev;
 269         simple_inode_init_ts(inode);
 270         inode->i_mapping->a_ops = &v9fs_addr_operations;
 271         inode->i_private = NULL;
 272
 273         switch (mode & S_IFMT) {
 274         case S_IFIFO:
 275         case S_IFBLK:
 276         case S_IFCHR:
 277         case S_IFSOCK:
 278                 if (v9fs_proto_dotl(v9ses)) {
 279                         inode->i_op = &v9fs_file_inode_operations_dotl;
 280                 } else if (v9fs_proto_dotu(v9ses)) {
 281                         inode->i_op = &v9fs_file_inode_operations;
 282                 } else {
 283                         p9_debug(P9_DEBUG_ERROR,
 284                                  "special files without extended mode\n");
 285                         err = -EINVAL;
 286                         goto error;
 287                 }
 288                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 289                 break;
 290         case S_IFREG:
 291                 if (v9fs_proto_dotl(v9ses)) {
 292                         inode->i_op = &v9fs_file_inode_operations_dotl;
 293                         inode->i_fop = &v9fs_file_operations_dotl;
 294                 } else {
 295                         inode->i_op = &v9fs_file_inode_operations;
 296                         inode->i_fop = &v9fs_file_operations;
 297                 }
 298
 299                 break;
 300         case S_IFLNK:
 301                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 302                         p9_debug(P9_DEBUG_ERROR,
 303                                  "extended modes used with legacy protocol\n");
 304                         err = -EINVAL;
 305                         goto error;
 306                 }
 307
 308                 if (v9fs_proto_dotl(v9ses))
 309                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
 310                 else
 311                         inode->i_op = &v9fs_symlink_inode_operations;
 312
 313                 break;
 314         case S_IFDIR:
 315                 inc_nlink(inode);
 316                 if (v9fs_proto_dotl(v9ses))
 317                         inode->i_op = &v9fs_dir_inode_operations_dotl;
 318                 else if (v9fs_proto_dotu(v9ses))
 319                         inode->i_op = &v9fs_dir_inode_operations_dotu;
 320                 else
 321                         inode->i_op = &v9fs_dir_inode_operations;
 322
 323                 if (v9fs_proto_dotl(v9ses))
 324                         inode->i_fop = &v9fs_dir_operations_dotl;
 325                 else
 326                         inode->i_fop = &v9fs_dir_operations;
 327
 328                 break;
 329         default:
 330                 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 331                          mode, mode & S_IFMT);
 332                 err = -EINVAL;
 333                 goto error;
 334         }
 335 error:
 336         return err;
 337
 338 }
 339
 340 /**
 341  * v9fs_evict_inode - Remove an inode from the inode cache
 342  * @inode: inode to release
 343  *
 344  */
 345 void v9fs_evict_inode(struct inode *inode)
 346 {
 347         struct v9fs_inode __maybe_unused *v9inode = V9FS_I(inode);
 348         __le32 __maybe_unused version;
 349
 350         if (!is_bad_inode(inode)) {
 351                 netfs_wait_for_outstanding_io(inode);
 352                 truncate_inode_pages_final(&inode->i_data);
 353
 354                 version = cpu_to_le32(v9inode->qid.version);
 355                 netfs_clear_inode_writeback(inode, &version);
 356
 357                 clear_inode(inode);
 358                 filemap_fdatawrite(&inode->i_data);
 359
 360 #ifdef CONFIG_9P_FSCACHE
 361                 if (v9fs_inode_cookie(v9inode))
 362                         fscache_relinquish_cookie(v9fs_inode_cookie(v9inode), false);
 363 #endif
 364         } else
 365                 clear_inode(inode);
 366 }
 367
 368 struct inode *
 369 v9fs_fid_iget(struct super_block *sb, struct p9_fid *fid, bool new)
 370 {
 371         dev_t rdev;
 372         int retval;
 373         umode_t umode;
 374         struct inode *inode;
 375         struct p9_wstat *st;
 376         struct v9fs_session_info *v9ses = sb->s_fs_info;
 377
 378         inode = iget_locked(sb, QID2INO(&fid->qid));
 379         if (unlikely(!inode))
 380                 return ERR_PTR(-ENOMEM);
 381         if (!(inode->i_state & I_NEW)) {
 382                 if (!new) {
 383                         goto done;
 384                 } else {
 385                         p9_debug(P9_DEBUG_VFS, "WARNING: Inode collision %ld\n",
 386                                                 inode->i_ino);
 387                         iput(inode);
 388                         remove_inode_hash(inode);
 389                         inode = iget_locked(sb, QID2INO(&fid->qid));
 390                         WARN_ON(!(inode->i_state & I_NEW));
 391                 }
 392         }
 393
 394         /*
 395          * initialize the inode with the stat info
 396          * FIXME!! we may need support for stale inodes
 397          * later.
 398          */
 399         st = p9_client_stat(fid);
 400         if (IS_ERR(st)) {
 401                 retval = PTR_ERR(st);
 402                 goto error;
 403         }
 404
 405         umode = p9mode2unixmode(v9ses, st, &rdev);
 406         retval = v9fs_init_inode(v9ses, inode, &fid->qid, umode, rdev);
 407         v9fs_stat2inode(st, inode, sb, 0);
 408         p9stat_free(st);
 409         kfree(st);
 410         if (retval)
 411                 goto error;
 412
 413         v9fs_set_netfs_context(inode);
 414         v9fs_cache_inode_get_cookie(inode);
 415         unlock_new_inode(inode);
 416 done:
 417         return inode;
 418 error:
 419         iget_failed(inode);
 420         return ERR_PTR(retval);
 421 }
 422
 423 /**
 424  * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 425  * plan 9 AT flag.
 426  * @flags: flags to convert
 427  */
 428 static int v9fs_at_to_dotl_flags(int flags)
 429 {
 430         int rflags = 0;
 431
 432         if (flags & AT_REMOVEDIR)
 433                 rflags |= P9_DOTL_AT_REMOVEDIR;
 434
 435         return rflags;
 436 }
 437
 438 /**
 439  * v9fs_dec_count - helper functon to drop i_nlink.
 440  *
 441  * If a directory had nlink <= 2 (including . and ..), then we should not drop
 442  * the link count, which indicates the underlying exported fs doesn't maintain
 443  * nlink accurately. e.g.
 444  * - overlayfs sets nlink to 1 for merged dir
 445  * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more
 446  *   than EXT4_LINK_MAX (65000) links.
 447  *
 448  * @inode: inode whose nlink is being dropped
 449  */
 450 static void v9fs_dec_count(struct inode *inode)
 451 {
 452         if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) {
 453                 if (inode->i_nlink) {
 454                         drop_nlink(inode);
 455                 } else {
 456                         p9_debug(P9_DEBUG_VFS,
 457                                                 "WARNING: unexpected i_nlink zero %d inode %ld\n",
 458                                                 inode->i_nlink, inode->i_ino);
 459                 }
 460         }
 461 }
 462
 463 /**
 464  * v9fs_remove - helper function to remove files and directories
 465  * @dir: directory inode that is being deleted
 466  * @dentry:  dentry that is being deleted
 467  * @flags: removing a directory
 468  *
 469  */
 470
 471 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 472 {
 473         struct inode *inode;
 474         int retval = -EOPNOTSUPP;
 475         struct p9_fid *v9fid, *dfid;
 476         struct v9fs_session_info *v9ses;
 477
 478         p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 479                  dir, dentry, flags);
 480
 481         v9ses = v9fs_inode2v9ses(dir);
 482         inode = d_inode(dentry);
 483         dfid = v9fs_parent_fid(dentry);
 484         if (IS_ERR(dfid)) {
 485                 retval = PTR_ERR(dfid);
 486                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 487                 return retval;
 488         }
 489         if (v9fs_proto_dotl(v9ses))
 490                 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 491                                             v9fs_at_to_dotl_flags(flags));
 492         p9_fid_put(dfid);
 493         if (retval == -EOPNOTSUPP) {
 494                 /* Try the one based on path */
 495                 v9fid = v9fs_fid_clone(dentry);
 496                 if (IS_ERR(v9fid))
 497                         return PTR_ERR(v9fid);
 498                 retval = p9_client_remove(v9fid);
 499         }
 500         if (!retval) {
 501                 /*
 502                  * directories on unlink should have zero
 503                  * link count
 504                  */
 505                 if (flags & AT_REMOVEDIR) {
 506                         clear_nlink(inode);
 507                         v9fs_dec_count(dir);
 508                 } else
 509                         v9fs_dec_count(inode);
 510
 511                 if (inode->i_nlink <= 0)        /* no more refs unhash it */
 512                         remove_inode_hash(inode);
 513
 514                 v9fs_invalidate_inode_attr(inode);
 515                 v9fs_invalidate_inode_attr(dir);
 516
 517                 /* invalidate all fids associated with dentry */
 518                 /* NOTE: This will not include open fids */
 519                 dentry->d_op->d_release(dentry);
 520         }
 521         return retval;
 522 }
 523
 524 /**
 525  * v9fs_create - Create a file
 526  * @v9ses: session information
 527  * @dir: directory that dentry is being created in
 528  * @dentry:  dentry that is being created
 529  * @extension: 9p2000.u extension string to support devices, etc.
 530  * @perm: create permissions
 531  * @mode: open mode
 532  *
 533  */
 534 static struct p9_fid *
 535 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 536                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 537 {
 538         int err;
 539         const unsigned char *name;
 540         struct p9_fid *dfid, *ofid = NULL, *fid = NULL;
 541         struct inode *inode;
 542
 543         p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 544
 545         name = dentry->d_name.name;
 546         dfid = v9fs_parent_fid(dentry);
 547         if (IS_ERR(dfid)) {
 548                 err = PTR_ERR(dfid);
 549                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 550                 return ERR_PTR(err);
 551         }
 552
 553         /* clone a fid to use for creation */
 554         ofid = clone_fid(dfid);
 555         if (IS_ERR(ofid)) {
 556                 err = PTR_ERR(ofid);
 557                 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 558                 goto error;
 559         }
 560
 561         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 562         if (err < 0) {
 563                 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 564                 goto error;
 565         }
 566
 567         if (!(perm & P9_DMLINK)) {
 568                 /* now walk from the parent so we can get unopened fid */
 569                 fid = p9_client_walk(dfid, 1, &name, 1);
 570                 if (IS_ERR(fid)) {
 571                         err = PTR_ERR(fid);
 572                         p9_debug(P9_DEBUG_VFS,
 573                                    "p9_client_walk failed %d\n", err);
 574                         goto error;
 575                 }
 576                 /*
 577                  * instantiate inode and assign the unopened fid to the dentry
 578                  */
 579                 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, true);
 580                 if (IS_ERR(inode)) {
 581                         err = PTR_ERR(inode);
 582                         p9_debug(P9_DEBUG_VFS,
 583                                    "inode creation failed %d\n", err);
 584                         goto error;
 585                 }
 586                 v9fs_fid_add(dentry, &fid);
 587                 d_instantiate(dentry, inode);
 588         }
 589         p9_fid_put(dfid);
 590         return ofid;
 591 error:
 592         p9_fid_put(dfid);
 593         p9_fid_put(ofid);
 594         p9_fid_put(fid);
 595         return ERR_PTR(err);
 596 }
 597
 598 /**
 599  * v9fs_vfs_create - VFS hook to create a regular file
 600  * @idmap: idmap of the mount
 601  * @dir: The parent directory
 602  * @dentry: The name of file to be created
 603  * @mode: The UNIX file mode to set
 604  * @excl: True if the file must not yet exist
 605  *
 606  * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 607  * for mknod(2).
 608  *
 609  */
 610
 611 static int
 612 v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
 613                 struct dentry *dentry, umode_t mode, bool excl)
 614 {
 615         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 616         u32 perm = unixmode2p9mode(v9ses, mode);
 617         struct p9_fid *fid;
 618
 619         /* P9_OEXCL? */
 620         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 621         if (IS_ERR(fid))
 622                 return PTR_ERR(fid);
 623
 624         v9fs_invalidate_inode_attr(dir);
 625         p9_fid_put(fid);
 626
 627         return 0;
 628 }
 629
 630 /**
 631  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 632  * @idmap: idmap of the mount
 633  * @dir:  inode that is being unlinked
 634  * @dentry: dentry that is being unlinked
 635  * @mode: mode for new directory
 636  *
 637  */
 638
 639 static int v9fs_vfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 640                           struct dentry *dentry, umode_t mode)
 641 {
 642         int err;
 643         u32 perm;
 644         struct p9_fid *fid;
 645         struct v9fs_session_info *v9ses;
 646
 647         p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 648         err = 0;
 649         v9ses = v9fs_inode2v9ses(dir);
 650         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 651         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 652         if (IS_ERR(fid)) {
 653                 err = PTR_ERR(fid);
 654                 fid = NULL;
 655         } else {
 656                 inc_nlink(dir);
 657                 v9fs_invalidate_inode_attr(dir);
 658         }
 659
 660         if (fid)
 661                 p9_fid_put(fid);
 662
 663         return err;
 664 }
 665
 666 /**
 667  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 668  * @dir:  inode that is being walked from
 669  * @dentry: dentry that is being walked to?
 670  * @flags: lookup flags (unused)
 671  *
 672  */
 673
 674 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 675                                       unsigned int flags)
 676 {
 677         struct dentry *res;
 678         struct v9fs_session_info *v9ses;
 679         struct p9_fid *dfid, *fid;
 680         struct inode *inode;
 681         const unsigned char *name;
 682
 683         p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
 684                  dir, dentry, dentry, flags);
 685
 686         if (dentry->d_name.len > NAME_MAX)
 687                 return ERR_PTR(-ENAMETOOLONG);
 688
 689         v9ses = v9fs_inode2v9ses(dir);
 690         /* We can walk d_parent because we hold the dir->i_mutex */
 691         dfid = v9fs_parent_fid(dentry);
 692         if (IS_ERR(dfid))
 693                 return ERR_CAST(dfid);
 694
 695         /*
 696          * Make sure we don't use a wrong inode due to parallel
 697          * unlink. For cached mode create calls request for new
 698          * inode. But with cache disabled, lookup should do this.
 699          */
 700         name = dentry->d_name.name;
 701         fid = p9_client_walk(dfid, 1, &name, 1);
 702         p9_fid_put(dfid);
 703         if (fid == ERR_PTR(-ENOENT))
 704                 inode = NULL;
 705         else if (IS_ERR(fid))
 706                 inode = ERR_CAST(fid);
 707         else
 708                 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb, false);
 709         /*
 710          * If we had a rename on the server and a parallel lookup
 711          * for the new name, then make sure we instantiate with
 712          * the new name. ie look up for a/b, while on server somebody
 713          * moved b under k and client parallely did a lookup for
 714          * k/b.
 715          */
 716         res = d_splice_alias(inode, dentry);
 717         if (!IS_ERR(fid)) {
 718                 if (!res)
 719                         v9fs_fid_add(dentry, &fid);
 720                 else if (!IS_ERR(res))
 721                         v9fs_fid_add(res, &fid);
 722                 else
 723                         p9_fid_put(fid);
 724         }
 725         return res;
 726 }
 727
 728 static int
 729 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 730                      struct file *file, unsigned int flags, umode_t mode)
 731 {
 732         int err;
 733         u32 perm;
 734         struct v9fs_inode __maybe_unused *v9inode;
 735         struct v9fs_session_info *v9ses;
 736         struct p9_fid *fid;
 737         struct dentry *res = NULL;
 738         struct inode *inode;
 739         int p9_omode;
 740
 741         if (d_in_lookup(dentry)) {
 742                 res = v9fs_vfs_lookup(dir, dentry, 0);
 743                 if (IS_ERR(res))
 744                         return PTR_ERR(res);
 745
 746                 if (res)
 747                         dentry = res;
 748         }
 749
 750         /* Only creates */
 751         if (!(flags & O_CREAT) || d_really_is_positive(dentry))
 752                 return finish_no_open(file, res);
 753
 754         v9ses = v9fs_inode2v9ses(dir);
 755         perm = unixmode2p9mode(v9ses, mode);
 756         p9_omode = v9fs_uflags2omode(flags, v9fs_proto_dotu(v9ses));
 757
 758         if ((v9ses->cache & CACHE_WRITEBACK) && (p9_omode & P9_OWRITE)) {
 759                 p9_omode = (p9_omode & ~P9_OWRITE) | P9_ORDWR;
 760                 p9_debug(P9_DEBUG_CACHE,
 761                         "write-only file with writeback enabled, creating w/ O_RDWR\n");
 762         }
 763         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, p9_omode);
 764         if (IS_ERR(fid)) {
 765                 err = PTR_ERR(fid);
 766                 goto error;
 767         }
 768
 769         v9fs_invalidate_inode_attr(dir);
 770         inode = d_inode(dentry);
 771         v9inode = V9FS_I(inode);
 772         err = finish_open(file, dentry, generic_file_open);
 773         if (err)
 774                 goto error;
 775
 776         file->private_data = fid;
 777 #ifdef CONFIG_9P_FSCACHE
 778         if (v9ses->cache & CACHE_FSCACHE)
 779                 fscache_use_cookie(v9fs_inode_cookie(v9inode),
 780                                    file->f_mode & FMODE_WRITE);
 781 #endif
 782
 783         v9fs_fid_add_modes(fid, v9ses->flags, v9ses->cache, file->f_flags);
 784         v9fs_open_fid_add(inode, &fid);
 785
 786         file->f_mode |= FMODE_CREATED;
 787 out:
 788         dput(res);
 789         return err;
 790
 791 error:
 792         p9_fid_put(fid);
 793         goto out;
 794 }
 795
 796 /**
 797  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 798  * @i:  inode that is being unlinked
 799  * @d: dentry that is being unlinked
 800  *
 801  */
 802
 803 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 804 {
 805         return v9fs_remove(i, d, 0);
 806 }
 807
 808 /**
 809  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 810  * @i:  inode that is being unlinked
 811  * @d: dentry that is being unlinked
 812  *
 813  */
 814
 815 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 816 {
 817         return v9fs_remove(i, d, AT_REMOVEDIR);
 818 }
 819
 820 /**
 821  * v9fs_vfs_rename - VFS hook to rename an inode
 822  * @idmap: The idmap of the mount
 823  * @old_dir:  old dir inode
 824  * @old_dentry: old dentry
 825  * @new_dir: new dir inode
 826  * @new_dentry: new dentry
 827  * @flags: RENAME_* flags
 828  *
 829  */
 830
 831 int
 832 v9fs_vfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
 833                 struct dentry *old_dentry, struct inode *new_dir,
 834                 struct dentry *new_dentry, unsigned int flags)
 835 {
 836         int retval;
 837         struct inode *old_inode;
 838         struct inode *new_inode;
 839         struct v9fs_session_info *v9ses;
 840         struct p9_fid *oldfid = NULL, *dfid = NULL;
 841         struct p9_fid *olddirfid = NULL;
 842         struct p9_fid *newdirfid = NULL;
 843         struct p9_wstat wstat;
 844
 845         if (flags)
 846                 return -EINVAL;
 847
 848         p9_debug(P9_DEBUG_VFS, "\n");
 849         old_inode = d_inode(old_dentry);
 850         new_inode = d_inode(new_dentry);
 851         v9ses = v9fs_inode2v9ses(old_inode);
 852         oldfid = v9fs_fid_lookup(old_dentry);
 853         if (IS_ERR(oldfid))
 854                 return PTR_ERR(oldfid);
 855
 856         dfid = v9fs_parent_fid(old_dentry);
 857         olddirfid = clone_fid(dfid);
 858         p9_fid_put(dfid);
 859         dfid = NULL;
 860
 861         if (IS_ERR(olddirfid)) {
 862                 retval = PTR_ERR(olddirfid);
 863                 goto error;
 864         }
 865
 866         dfid = v9fs_parent_fid(new_dentry);
 867         newdirfid = clone_fid(dfid);
 868         p9_fid_put(dfid);
 869         dfid = NULL;
 870
 871         if (IS_ERR(newdirfid)) {
 872                 retval = PTR_ERR(newdirfid);
 873                 goto error;
 874         }
 875
 876         down_write(&v9ses->rename_sem);
 877         if (v9fs_proto_dotl(v9ses)) {
 878                 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 879                                             newdirfid, new_dentry->d_name.name);
 880                 if (retval == -EOPNOTSUPP)
 881                         retval = p9_client_rename(oldfid, newdirfid,
 882                                                   new_dentry->d_name.name);
 883                 if (retval != -EOPNOTSUPP)
 884                         goto error_locked;
 885         }
 886         if (old_dentry->d_parent != new_dentry->d_parent) {
 887                 /*
 888                  * 9P .u can only handle file rename in the same directory
 889                  */
 890
 891                 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
 892                 retval = -EXDEV;
 893                 goto error_locked;
 894         }
 895         v9fs_blank_wstat(&wstat);
 896         wstat.muid = v9ses->uname;
 897         wstat.name = new_dentry->d_name.name;
 898         retval = p9_client_wstat(oldfid, &wstat);
 899
 900 error_locked:
 901         if (!retval) {
 902                 if (new_inode) {
 903                         if (S_ISDIR(new_inode->i_mode))
 904                                 clear_nlink(new_inode);
 905                         else
 906                                 v9fs_dec_count(new_inode);
 907                 }
 908                 if (S_ISDIR(old_inode->i_mode)) {
 909                         if (!new_inode)
 910                                 inc_nlink(new_dir);
 911                         v9fs_dec_count(old_dir);
 912                 }
 913                 v9fs_invalidate_inode_attr(old_inode);
 914                 v9fs_invalidate_inode_attr(old_dir);
 915                 v9fs_invalidate_inode_attr(new_dir);
 916
 917                 /* successful rename */
 918                 d_move(old_dentry, new_dentry);
 919         }
 920         up_write(&v9ses->rename_sem);
 921
 922 error:
 923         p9_fid_put(newdirfid);
 924         p9_fid_put(olddirfid);
 925         p9_fid_put(oldfid);
 926         return retval;
 927 }
 928
 929 /**
 930  * v9fs_vfs_getattr - retrieve file metadata
 931  * @idmap: idmap of the mount
 932  * @path: Object to query
 933  * @stat: metadata structure to populate
 934  * @request_mask: Mask of STATX_xxx flags indicating the caller's interests
 935  * @flags: AT_STATX_xxx setting
 936  *
 937  */
 938
 939 static int
 940 v9fs_vfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 941                  struct kstat *stat, u32 request_mask, unsigned int flags)
 942 {
 943         struct dentry *dentry = path->dentry;
 944         struct inode *inode = d_inode(dentry);
 945         struct v9fs_session_info *v9ses;
 946         struct p9_fid *fid;
 947         struct p9_wstat *st;
 948
 949         p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 950         v9ses = v9fs_dentry2v9ses(dentry);
 951         if (v9ses->cache & (CACHE_META|CACHE_LOOSE)) {
 952                 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
 953                 return 0;
 954         } else if (v9ses->cache & CACHE_WRITEBACK) {
 955                 if (S_ISREG(inode->i_mode)) {
 956                         int retval = filemap_fdatawrite(inode->i_mapping);
 957
 958                         if (retval)
 959                                 p9_debug(P9_DEBUG_ERROR,
 960                                     "flushing writeback during getattr returned %d\n", retval);
 961                 }
 962         }
 963         fid = v9fs_fid_lookup(dentry);
 964         if (IS_ERR(fid))
 965                 return PTR_ERR(fid);
 966
 967         st = p9_client_stat(fid);
 968         p9_fid_put(fid);
 969         if (IS_ERR(st))
 970                 return PTR_ERR(st);
 971
 972         v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0);
 973         generic_fillattr(&nop_mnt_idmap, request_mask, d_inode(dentry), stat);
 974
 975         p9stat_free(st);
 976         kfree(st);
 977         return 0;
 978 }
 979
 980 /**
 981  * v9fs_vfs_setattr - set file metadata
 982  * @idmap: idmap of the mount
 983  * @dentry: file whose metadata to set
 984  * @iattr: metadata assignment structure
 985  *
 986  */
 987
 988 static int v9fs_vfs_setattr(struct mnt_idmap *idmap,
 989                             struct dentry *dentry, struct iattr *iattr)
 990 {
 991         int retval, use_dentry = 0;
 992         struct inode *inode = d_inode(dentry);
 993         struct v9fs_session_info *v9ses;
 994         struct p9_fid *fid = NULL;
 995         struct p9_wstat wstat;
 996
 997         p9_debug(P9_DEBUG_VFS, "\n");
 998         retval = setattr_prepare(&nop_mnt_idmap, dentry, iattr);
 999         if (retval)
1000                 return retval;
1001
1002         v9ses = v9fs_dentry2v9ses(dentry);
1003         if (iattr->ia_valid & ATTR_FILE) {
1004                 fid = iattr->ia_file->private_data;
1005                 WARN_ON(!fid);
1006         }
1007         if (!fid) {
1008                 fid = v9fs_fid_lookup(dentry);
1009                 use_dentry = 1;
1010         }
1011         if (IS_ERR(fid))
1012                 return PTR_ERR(fid);
1013
1014         v9fs_blank_wstat(&wstat);
1015         if (iattr->ia_valid & ATTR_MODE)
1016                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1017
1018         if (iattr->ia_valid & ATTR_MTIME)
1019                 wstat.mtime = iattr->ia_mtime.tv_sec;
1020
1021         if (iattr->ia_valid & ATTR_ATIME)
1022                 wstat.atime = iattr->ia_atime.tv_sec;
1023
1024         if (iattr->ia_valid & ATTR_SIZE)
1025                 wstat.length = iattr->ia_size;
1026
1027         if (v9fs_proto_dotu(v9ses)) {
1028                 if (iattr->ia_valid & ATTR_UID)
1029                         wstat.n_uid = iattr->ia_uid;
1030
1031                 if (iattr->ia_valid & ATTR_GID)
1032                         wstat.n_gid = iattr->ia_gid;
1033         }
1034
1035         /* Write all dirty data */
1036         if (d_is_reg(dentry)) {
1037                 retval = filemap_fdatawrite(inode->i_mapping);
1038                 if (retval)
1039                         p9_debug(P9_DEBUG_ERROR,
1040                             "flushing writeback during setattr returned %d\n", retval);
1041         }
1042
1043         retval = p9_client_wstat(fid, &wstat);
1044
1045         if (use_dentry)
1046                 p9_fid_put(fid);
1047
1048         if (retval < 0)
1049                 return retval;
1050
1051         if ((iattr->ia_valid & ATTR_SIZE) &&
1052                  iattr->ia_size != i_size_read(inode)) {
1053                 truncate_setsize(inode, iattr->ia_size);
1054                 netfs_resize_file(netfs_inode(inode), iattr->ia_size, true);
1055
1056 #ifdef CONFIG_9P_FSCACHE
1057                 if (v9ses->cache & CACHE_FSCACHE) {
1058                         struct v9fs_inode *v9inode = V9FS_I(inode);
1059
1060                         fscache_resize_cookie(v9fs_inode_cookie(v9inode), iattr->ia_size);
1061                 }
1062 #endif
1063         }
1064
1065         v9fs_invalidate_inode_attr(inode);
1066
1067         setattr_copy(&nop_mnt_idmap, inode, iattr);
1068         mark_inode_dirty(inode);
1069         return 0;
1070 }
1071
1072 /**
1073  * v9fs_stat2inode - populate an inode structure with mistat info
1074  * @stat: Plan 9 metadata (mistat) structure
1075  * @inode: inode to populate
1076  * @sb: superblock of filesystem
1077  * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE)
1078  *
1079  */
1080
1081 void
1082 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1083                  struct super_block *sb, unsigned int flags)
1084 {
1085         umode_t mode;
1086         struct v9fs_session_info *v9ses = sb->s_fs_info;
1087         struct v9fs_inode *v9inode = V9FS_I(inode);
1088
1089         inode_set_atime(inode, stat->atime, 0);
1090         inode_set_mtime(inode, stat->mtime, 0);
1091         inode_set_ctime(inode, stat->mtime, 0);
1092
1093         inode->i_uid = v9ses->dfltuid;
1094         inode->i_gid = v9ses->dfltgid;
1095
1096         if (v9fs_proto_dotu(v9ses)) {
1097                 inode->i_uid = stat->n_uid;
1098                 inode->i_gid = stat->n_gid;
1099         }
1100         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1101                 if (v9fs_proto_dotu(v9ses)) {
1102                         unsigned int i_nlink;
1103                         /*
1104                          * Hadlink support got added later to the .u extension.
1105                          * So there can be a server out there that doesn't
1106                          * support this even with .u extension. That would
1107                          * just leave us with stat->extension being an empty
1108                          * string, though.
1109                          */
1110                         /* HARDLINKCOUNT %u */
1111                         if (sscanf(stat->extension,
1112                                    " HARDLINKCOUNT %u", &i_nlink) == 1)
1113                                 set_nlink(inode, i_nlink);
1114                 }
1115         }
1116         mode = p9mode2perm(v9ses, stat);
1117         mode |= inode->i_mode & ~S_IALLUGO;
1118         inode->i_mode = mode;
1119
1120         v9inode->netfs.remote_i_size = stat->length;
1121         if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE))
1122                 v9fs_i_size_write(inode, stat->length);
1123         /* not real number of blocks, but 512 byte ones ... */
1124         inode->i_blocks = (stat->length + 512 - 1) >> 9;
1125         v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1126 }
1127
1128 /**
1129  * v9fs_vfs_get_link - follow a symlink path
1130  * @dentry: dentry for symlink
1131  * @inode: inode for symlink
1132  * @done: delayed call for when we are done with the return value
1133  */
1134
1135 static const char *v9fs_vfs_get_link(struct dentry *dentry,
1136                                      struct inode *inode,
1137                                      struct delayed_call *done)
1138 {
1139         struct v9fs_session_info *v9ses;
1140         struct p9_fid *fid;
1141         struct p9_wstat *st;
1142         char *res;
1143
1144         if (!dentry)
1145                 return ERR_PTR(-ECHILD);
1146
1147         v9ses = v9fs_dentry2v9ses(dentry);
1148         if (!v9fs_proto_dotu(v9ses))
1149                 return ERR_PTR(-EBADF);
1150
1151         p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1152         fid = v9fs_fid_lookup(dentry);
1153
1154         if (IS_ERR(fid))
1155                 return ERR_CAST(fid);
1156
1157         st = p9_client_stat(fid);
1158         p9_fid_put(fid);
1159         if (IS_ERR(st))
1160                 return ERR_CAST(st);
1161
1162         if (!(st->mode & P9_DMSYMLINK)) {
1163                 p9stat_free(st);
1164                 kfree(st);
1165                 return ERR_PTR(-EINVAL);
1166         }
1167         res = st->extension;
1168         st->extension = NULL;
1169         if (strlen(res) >= PATH_MAX)
1170                 res[PATH_MAX - 1] = '\0';
1171
1172         p9stat_free(st);
1173         kfree(st);
1174         set_delayed_call(done, kfree_link, res);
1175         return res;
1176 }
1177
1178 /**
1179  * v9fs_vfs_mkspecial - create a special file
1180  * @dir: inode to create special file in
1181  * @dentry: dentry to create
1182  * @perm: mode to create special file
1183  * @extension: 9p2000.u format extension string representing special file
1184  *
1185  */
1186
1187 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1188         u32 perm, const char *extension)
1189 {
1190         struct p9_fid *fid;
1191         struct v9fs_session_info *v9ses;
1192
1193         v9ses = v9fs_inode2v9ses(dir);
1194         if (!v9fs_proto_dotu(v9ses)) {
1195                 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1196                 return -EPERM;
1197         }
1198
1199         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1200                                                                 P9_OREAD);
1201         if (IS_ERR(fid))
1202                 return PTR_ERR(fid);
1203
1204         v9fs_invalidate_inode_attr(dir);
1205         p9_fid_put(fid);
1206         return 0;
1207 }
1208
1209 /**
1210  * v9fs_vfs_symlink - helper function to create symlinks
1211  * @idmap: idmap of the mount
1212  * @dir: directory inode containing symlink
1213  * @dentry: dentry for symlink
1214  * @symname: symlink data
1215  *
1216  * See Also: 9P2000.u RFC for more information
1217  *
1218  */
1219
1220 static int
1221 v9fs_vfs_symlink(struct mnt_idmap *idmap, struct inode *dir,
1222                  struct dentry *dentry, const char *symname)
1223 {
1224         p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1225                  dir->i_ino, dentry, symname);
1226
1227         return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1228 }
1229
1230 #define U32_MAX_DIGITS 10
1231
1232 /**
1233  * v9fs_vfs_link - create a hardlink
1234  * @old_dentry: dentry for file to link to
1235  * @dir: inode destination for new link
1236  * @dentry: dentry for link
1237  *
1238  */
1239
1240 static int
1241 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1242               struct dentry *dentry)
1243 {
1244         int retval;
1245         char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1246         struct p9_fid *oldfid;
1247
1248         p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1249                  dir->i_ino, dentry, old_dentry);
1250
1251         oldfid = v9fs_fid_clone(old_dentry);
1252         if (IS_ERR(oldfid))
1253                 return PTR_ERR(oldfid);
1254
1255         sprintf(name, "%d\n", oldfid->fid);
1256         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1257         if (!retval) {
1258                 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1259                 v9fs_invalidate_inode_attr(dir);
1260         }
1261         p9_fid_put(oldfid);
1262         return retval;
1263 }
1264
1265 /**
1266  * v9fs_vfs_mknod - create a special file
1267  * @idmap: idmap of the mount
1268  * @dir: inode destination for new link
1269  * @dentry: dentry for file
1270  * @mode: mode for creation
1271  * @rdev: device associated with special file
1272  *
1273  */
1274
1275 static int
1276 v9fs_vfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
1277                struct dentry *dentry, umode_t mode, dev_t rdev)
1278 {
1279         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1280         int retval;
1281         char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1282         u32 perm;
1283
1284         p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %x MAJOR: %u MINOR: %u\n",
1285                  dir->i_ino, dentry, mode,
1286                  MAJOR(rdev), MINOR(rdev));
1287
1288         /* build extension */
1289         if (S_ISBLK(mode))
1290                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1291         else if (S_ISCHR(mode))
1292                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1293         else
1294                 *name = 0;
1295
1296         perm = unixmode2p9mode(v9ses, mode);
1297         retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1298
1299         return retval;
1300 }
1301
1302 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1303 {
1304         int umode;
1305         dev_t rdev;
1306         struct p9_wstat *st;
1307         struct v9fs_session_info *v9ses;
1308         unsigned int flags;
1309
1310         v9ses = v9fs_inode2v9ses(inode);
1311         st = p9_client_stat(fid);
1312         if (IS_ERR(st))
1313                 return PTR_ERR(st);
1314         /*
1315          * Don't update inode if the file type is different
1316          */
1317         umode = p9mode2unixmode(v9ses, st, &rdev);
1318         if (inode_wrong_type(inode, umode))
1319                 goto out;
1320
1321         /*
1322          * We don't want to refresh inode->i_size,
1323          * because we may have cached data
1324          */
1325         flags = (v9ses->cache & CACHE_LOOSE) ?
1326                 V9FS_STAT2INODE_KEEP_ISIZE : 0;
1327         v9fs_stat2inode(st, inode, inode->i_sb, flags);
1328 out:
1329         p9stat_free(st);
1330         kfree(st);
1331         return 0;
1332 }
1333
1334 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1335         .create = v9fs_vfs_create,
1336         .lookup = v9fs_vfs_lookup,
1337         .atomic_open = v9fs_vfs_atomic_open,
1338         .symlink = v9fs_vfs_symlink,
1339         .link = v9fs_vfs_link,
1340         .unlink = v9fs_vfs_unlink,
1341         .mkdir = v9fs_vfs_mkdir,
1342         .rmdir = v9fs_vfs_rmdir,
1343         .mknod = v9fs_vfs_mknod,
1344         .rename = v9fs_vfs_rename,
1345         .getattr = v9fs_vfs_getattr,
1346         .setattr = v9fs_vfs_setattr,
1347 };
1348
1349 static const struct inode_operations v9fs_dir_inode_operations = {
1350         .create = v9fs_vfs_create,
1351         .lookup = v9fs_vfs_lookup,
1352         .atomic_open = v9fs_vfs_atomic_open,
1353         .unlink = v9fs_vfs_unlink,
1354         .mkdir = v9fs_vfs_mkdir,
1355         .rmdir = v9fs_vfs_rmdir,
1356         .mknod = v9fs_vfs_mknod,
1357         .rename = v9fs_vfs_rename,
1358         .getattr = v9fs_vfs_getattr,
1359         .setattr = v9fs_vfs_setattr,
1360 };
1361
1362 static const struct inode_operations v9fs_file_inode_operations = {
1363         .getattr = v9fs_vfs_getattr,
1364         .setattr = v9fs_vfs_setattr,
1365 };
1366
1367 static const struct inode_operations v9fs_symlink_inode_operations = {
1368         .get_link = v9fs_vfs_get_link,
1369         .getattr = v9fs_vfs_getattr,
1370         .setattr = v9fs_vfs_setattr,
1371 };
1372