fs/9p/vfs_inode.c

   1 /*
   2  *  linux/fs/9p/vfs_inode.c
   3  *
   4  * This file contains vfs inode ops for the 9P2000 protocol.
   5  *
   6  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/file.h>
  32 #include <linux/pagemap.h>
  33 #include <linux/stat.h>
  34 #include <linux/string.h>
  35 #include <linux/inet.h>
  36 #include <linux/namei.h>
  37 #include <linux/idr.h>
  38 #include <linux/sched.h>
  39 #include <linux/slab.h>
  40 #include <linux/xattr.h>
  41 #include <linux/posix_acl.h>
  42 #include <net/9p/9p.h>
  43 #include <net/9p/client.h>
  44
  45 #include "v9fs.h"
  46 #include "v9fs_vfs.h"
  47 #include "fid.h"
  48 #include "cache.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51
  52 static const struct inode_operations v9fs_dir_inode_operations;
  53 static const struct inode_operations v9fs_dir_inode_operations_dotu;
  54 static const struct inode_operations v9fs_file_inode_operations;
  55 static const struct inode_operations v9fs_symlink_inode_operations;
  56
  57 /**
  58  * unixmode2p9mode - convert unix mode bits to plan 9
  59  * @v9ses: v9fs session information
  60  * @mode: mode to convert
  61  *
  62  */
  63
  64 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
  65 {
  66         int res;
  67         res = mode & 0777;
  68         if (S_ISDIR(mode))
  69                 res |= P9_DMDIR;
  70         if (v9fs_proto_dotu(v9ses)) {
  71                 if (v9ses->nodev == 0) {
  72                         if (S_ISSOCK(mode))
  73                                 res |= P9_DMSOCKET;
  74                         if (S_ISFIFO(mode))
  75                                 res |= P9_DMNAMEDPIPE;
  76                         if (S_ISBLK(mode))
  77                                 res |= P9_DMDEVICE;
  78                         if (S_ISCHR(mode))
  79                                 res |= P9_DMDEVICE;
  80                 }
  81
  82                 if ((mode & S_ISUID) == S_ISUID)
  83                         res |= P9_DMSETUID;
  84                 if ((mode & S_ISGID) == S_ISGID)
  85                         res |= P9_DMSETGID;
  86                 if ((mode & S_ISVTX) == S_ISVTX)
  87                         res |= P9_DMSETVTX;
  88         }
  89         return res;
  90 }
  91
  92 /**
  93  * p9mode2perm- convert plan9 mode bits to unix permission bits
  94  * @v9ses: v9fs session information
  95  * @stat: p9_wstat from which mode need to be derived
  96  *
  97  */
  98 static int p9mode2perm(struct v9fs_session_info *v9ses,
  99                        struct p9_wstat *stat)
 100 {
 101         int res;
 102         int mode = stat->mode;
 103
 104         res = mode & S_IALLUGO;
 105         if (v9fs_proto_dotu(v9ses)) {
 106                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
 107                         res |= S_ISUID;
 108
 109                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
 110                         res |= S_ISGID;
 111
 112                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 113                         res |= S_ISVTX;
 114         }
 115         return res;
 116 }
 117
 118 /**
 119  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
 120  * @v9ses: v9fs session information
 121  * @stat: p9_wstat from which mode need to be derived
 122  * @rdev: major number, minor number in case of device files.
 123  *
 124  */
 125 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
 126                                struct p9_wstat *stat, dev_t *rdev)
 127 {
 128         int res;
 129         u32 mode = stat->mode;
 130
 131         *rdev = 0;
 132         res = p9mode2perm(v9ses, stat);
 133
 134         if ((mode & P9_DMDIR) == P9_DMDIR)
 135                 res |= S_IFDIR;
 136         else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 137                 res |= S_IFLNK;
 138         else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 139                  && (v9ses->nodev == 0))
 140                 res |= S_IFSOCK;
 141         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 142                  && (v9ses->nodev == 0))
 143                 res |= S_IFIFO;
 144         else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 145                  && (v9ses->nodev == 0)) {
 146                 char type = 0, ext[32];
 147                 int major = -1, minor = -1;
 148
 149                 strlcpy(ext, stat->extension, sizeof(ext));
 150                 sscanf(ext, "%c %i %i", &type, &major, &minor);
 151                 switch (type) {
 152                 case 'c':
 153                         res |= S_IFCHR;
 154                         break;
 155                 case 'b':
 156                         res |= S_IFBLK;
 157                         break;
 158                 default:
 159                         p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
 160                                  type, stat->extension);
 161                 };
 162                 *rdev = MKDEV(major, minor);
 163         } else
 164                 res |= S_IFREG;
 165
 166         return res;
 167 }
 168
 169 /**
 170  * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 171  * @uflags: flags to convert
 172  * @extended: if .u extensions are active
 173  */
 174
 175 int v9fs_uflags2omode(int uflags, int extended)
 176 {
 177         int ret;
 178
 179         ret = 0;
 180         switch (uflags&3) {
 181         default:
 182         case O_RDONLY:
 183                 ret = P9_OREAD;
 184                 break;
 185
 186         case O_WRONLY:
 187                 ret = P9_OWRITE;
 188                 break;
 189
 190         case O_RDWR:
 191                 ret = P9_ORDWR;
 192                 break;
 193         }
 194
 195         if (extended) {
 196                 if (uflags & O_EXCL)
 197                         ret |= P9_OEXCL;
 198
 199                 if (uflags & O_APPEND)
 200                         ret |= P9_OAPPEND;
 201         }
 202
 203         return ret;
 204 }
 205
 206 /**
 207  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 208  * @wstat: structure to initialize
 209  *
 210  */
 211
 212 void
 213 v9fs_blank_wstat(struct p9_wstat *wstat)
 214 {
 215         wstat->type = ~0;
 216         wstat->dev = ~0;
 217         wstat->qid.type = ~0;
 218         wstat->qid.version = ~0;
 219         *((long long *)&wstat->qid.path) = ~0;
 220         wstat->mode = ~0;
 221         wstat->atime = ~0;
 222         wstat->mtime = ~0;
 223         wstat->length = ~0;
 224         wstat->name = NULL;
 225         wstat->uid = NULL;
 226         wstat->gid = NULL;
 227         wstat->muid = NULL;
 228         wstat->n_uid = INVALID_UID;
 229         wstat->n_gid = INVALID_GID;
 230         wstat->n_muid = INVALID_UID;
 231         wstat->extension = NULL;
 232 }
 233
 234 /**
 235  * v9fs_alloc_inode - helper function to allocate an inode
 236  *
 237  */
 238 struct inode *v9fs_alloc_inode(struct super_block *sb)
 239 {
 240         struct v9fs_inode *v9inode;
 241         v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 242                                                         GFP_KERNEL);
 243         if (!v9inode)
 244                 return NULL;
 245 #ifdef CONFIG_9P_FSCACHE
 246         v9inode->fscache = NULL;
 247         spin_lock_init(&v9inode->fscache_lock);
 248 #endif
 249         v9inode->writeback_fid = NULL;
 250         v9inode->cache_validity = 0;
 251         mutex_init(&v9inode->v_mutex);
 252         return &v9inode->vfs_inode;
 253 }
 254
 255 /**
 256  * v9fs_destroy_inode - destroy an inode
 257  *
 258  */
 259
 260 static void v9fs_i_callback(struct rcu_head *head)
 261 {
 262         struct inode *inode = container_of(head, struct inode, i_rcu);
 263         kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 264 }
 265
 266 void v9fs_destroy_inode(struct inode *inode)
 267 {
 268         call_rcu(&inode->i_rcu, v9fs_i_callback);
 269 }
 270
 271 int v9fs_init_inode(struct v9fs_session_info *v9ses,
 272                     struct inode *inode, umode_t mode, dev_t rdev)
 273 {
 274         int err = 0;
 275
 276         inode_init_owner(inode, NULL, mode);
 277         inode->i_blocks = 0;
 278         inode->i_rdev = rdev;
 279         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 280         inode->i_mapping->a_ops = &v9fs_addr_operations;
 281
 282         switch (mode & S_IFMT) {
 283         case S_IFIFO:
 284         case S_IFBLK:
 285         case S_IFCHR:
 286         case S_IFSOCK:
 287                 if (v9fs_proto_dotl(v9ses)) {
 288                         inode->i_op = &v9fs_file_inode_operations_dotl;
 289                 } else if (v9fs_proto_dotu(v9ses)) {
 290                         inode->i_op = &v9fs_file_inode_operations;
 291                 } else {
 292                         p9_debug(P9_DEBUG_ERROR,
 293                                  "special files without extended mode\n");
 294                         err = -EINVAL;
 295                         goto error;
 296                 }
 297                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 298                 break;
 299         case S_IFREG:
 300                 if (v9fs_proto_dotl(v9ses)) {
 301                         inode->i_op = &v9fs_file_inode_operations_dotl;
 302                         if (v9ses->cache == CACHE_LOOSE ||
 303                             v9ses->cache == CACHE_FSCACHE)
 304                                 inode->i_fop =
 305                                         &v9fs_cached_file_operations_dotl;
 306                         else if (v9ses->cache == CACHE_MMAP)
 307                                 inode->i_fop = &v9fs_mmap_file_operations_dotl;
 308                         else
 309                                 inode->i_fop = &v9fs_file_operations_dotl;
 310                 } else {
 311                         inode->i_op = &v9fs_file_inode_operations;
 312                         if (v9ses->cache == CACHE_LOOSE ||
 313                             v9ses->cache == CACHE_FSCACHE)
 314                                 inode->i_fop =
 315                                         &v9fs_cached_file_operations;
 316                         else if (v9ses->cache == CACHE_MMAP)
 317                                 inode->i_fop = &v9fs_mmap_file_operations;
 318                         else
 319                                 inode->i_fop = &v9fs_file_operations;
 320                 }
 321
 322                 break;
 323         case S_IFLNK:
 324                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 325                         p9_debug(P9_DEBUG_ERROR,
 326                                  "extended modes used with legacy protocol\n");
 327                         err = -EINVAL;
 328                         goto error;
 329                 }
 330
 331                 if (v9fs_proto_dotl(v9ses))
 332                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
 333                 else
 334                         inode->i_op = &v9fs_symlink_inode_operations;
 335
 336                 break;
 337         case S_IFDIR:
 338                 inc_nlink(inode);
 339                 if (v9fs_proto_dotl(v9ses))
 340                         inode->i_op = &v9fs_dir_inode_operations_dotl;
 341                 else if (v9fs_proto_dotu(v9ses))
 342                         inode->i_op = &v9fs_dir_inode_operations_dotu;
 343                 else
 344                         inode->i_op = &v9fs_dir_inode_operations;
 345
 346                 if (v9fs_proto_dotl(v9ses))
 347                         inode->i_fop = &v9fs_dir_operations_dotl;
 348                 else
 349                         inode->i_fop = &v9fs_dir_operations;
 350
 351                 break;
 352         default:
 353                 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 354                          mode, mode & S_IFMT);
 355                 err = -EINVAL;
 356                 goto error;
 357         }
 358 error:
 359         return err;
 360
 361 }
 362
 363 /**
 364  * v9fs_get_inode - helper function to setup an inode
 365  * @sb: superblock
 366  * @mode: mode to setup inode with
 367  *
 368  */
 369
 370 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 371 {
 372         int err;
 373         struct inode *inode;
 374         struct v9fs_session_info *v9ses = sb->s_fs_info;
 375
 376         p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 377
 378         inode = new_inode(sb);
 379         if (!inode) {
 380                 pr_warn("%s (%d): Problem allocating inode\n",
 381                         __func__, task_pid_nr(current));
 382                 return ERR_PTR(-ENOMEM);
 383         }
 384         err = v9fs_init_inode(v9ses, inode, mode, rdev);
 385         if (err) {
 386                 iput(inode);
 387                 return ERR_PTR(err);
 388         }
 389         return inode;
 390 }
 391
 392 /*
 393 static struct v9fs_fid*
 394 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 395 {
 396         int err;
 397         int nfid;
 398         struct v9fs_fid *ret;
 399         struct v9fs_fcall *fcall;
 400
 401         nfid = v9fs_get_idpool(&v9ses->fidpool);
 402         if (nfid < 0) {
 403                 eprintk(KERN_WARNING, "no free fids available\n");
 404                 return ERR_PTR(-ENOSPC);
 405         }
 406
 407         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 408                 &fcall);
 409
 410         if (err < 0) {
 411                 if (fcall && fcall->id == RWALK)
 412                         goto clunk_fid;
 413
 414                 PRINT_FCALL_ERROR("walk error", fcall);
 415                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 416                 goto error;
 417         }
 418
 419         kfree(fcall);
 420         fcall = NULL;
 421         ret = v9fs_fid_create(v9ses, nfid);
 422         if (!ret) {
 423                 err = -ENOMEM;
 424                 goto clunk_fid;
 425         }
 426
 427         err = v9fs_fid_insert(ret, dentry);
 428         if (err < 0) {
 429                 v9fs_fid_destroy(ret);
 430                 goto clunk_fid;
 431         }
 432
 433         return ret;
 434
 435 clunk_fid:
 436         v9fs_t_clunk(v9ses, nfid);
 437
 438 error:
 439         kfree(fcall);
 440         return ERR_PTR(err);
 441 }
 442 */
 443
 444
 445 /**
 446  * v9fs_clear_inode - release an inode
 447  * @inode: inode to release
 448  *
 449  */
 450 void v9fs_evict_inode(struct inode *inode)
 451 {
 452         struct v9fs_inode *v9inode = V9FS_I(inode);
 453
 454         truncate_inode_pages_final(&inode->i_data);
 455         clear_inode(inode);
 456         filemap_fdatawrite(&inode->i_data);
 457
 458         v9fs_cache_inode_put_cookie(inode);
 459         /* clunk the fid stashed in writeback_fid */
 460         if (v9inode->writeback_fid) {
 461                 p9_client_clunk(v9inode->writeback_fid);
 462                 v9inode->writeback_fid = NULL;
 463         }
 464 }
 465
 466 static int v9fs_test_inode(struct inode *inode, void *data)
 467 {
 468         int umode;
 469         dev_t rdev;
 470         struct v9fs_inode *v9inode = V9FS_I(inode);
 471         struct p9_wstat *st = (struct p9_wstat *)data;
 472         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 473
 474         umode = p9mode2unixmode(v9ses, st, &rdev);
 475         /* don't match inode of different type */
 476         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 477                 return 0;
 478
 479         /* compare qid details */
 480         if (memcmp(&v9inode->qid.version,
 481                    &st->qid.version, sizeof(v9inode->qid.version)))
 482                 return 0;
 483
 484         if (v9inode->qid.type != st->qid.type)
 485                 return 0;
 486         return 1;
 487 }
 488
 489 static int v9fs_test_new_inode(struct inode *inode, void *data)
 490 {
 491         return 0;
 492 }
 493
 494 static int v9fs_set_inode(struct inode *inode,  void *data)
 495 {
 496         struct v9fs_inode *v9inode = V9FS_I(inode);
 497         struct p9_wstat *st = (struct p9_wstat *)data;
 498
 499         memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 500         return 0;
 501 }
 502
 503 static struct inode *v9fs_qid_iget(struct super_block *sb,
 504                                    struct p9_qid *qid,
 505                                    struct p9_wstat *st,
 506                                    int new)
 507 {
 508         dev_t rdev;
 509         int retval;
 510         umode_t umode;
 511         unsigned long i_ino;
 512         struct inode *inode;
 513         struct v9fs_session_info *v9ses = sb->s_fs_info;
 514         int (*test)(struct inode *, void *);
 515
 516         if (new)
 517                 test = v9fs_test_new_inode;
 518         else
 519                 test = v9fs_test_inode;
 520
 521         i_ino = v9fs_qid2ino(qid);
 522         inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 523         if (!inode)
 524                 return ERR_PTR(-ENOMEM);
 525         if (!(inode->i_state & I_NEW))
 526                 return inode;
 527         /*
 528          * initialize the inode with the stat info
 529          * FIXME!! we may need support for stale inodes
 530          * later.
 531          */
 532         inode->i_ino = i_ino;
 533         umode = p9mode2unixmode(v9ses, st, &rdev);
 534         retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 535         if (retval)
 536                 goto error;
 537
 538         v9fs_stat2inode(st, inode, sb);
 539         v9fs_cache_inode_get_cookie(inode);
 540         unlock_new_inode(inode);
 541         return inode;
 542 error:
 543         iget_failed(inode);
 544         return ERR_PTR(retval);
 545
 546 }
 547
 548 struct inode *
 549 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 550                     struct super_block *sb, int new)
 551 {
 552         struct p9_wstat *st;
 553         struct inode *inode = NULL;
 554
 555         st = p9_client_stat(fid);
 556         if (IS_ERR(st))
 557                 return ERR_CAST(st);
 558
 559         inode = v9fs_qid_iget(sb, &st->qid, st, new);
 560         p9stat_free(st);
 561         kfree(st);
 562         return inode;
 563 }
 564
 565 /**
 566  * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 567  * plan 9 AT flag.
 568  * @flags: flags to convert
 569  */
 570 static int v9fs_at_to_dotl_flags(int flags)
 571 {
 572         int rflags = 0;
 573         if (flags & AT_REMOVEDIR)
 574                 rflags |= P9_DOTL_AT_REMOVEDIR;
 575         return rflags;
 576 }
 577
 578 /**
 579  * v9fs_remove - helper function to remove files and directories
 580  * @dir: directory inode that is being deleted
 581  * @dentry:  dentry that is being deleted
 582  * @flags: removing a directory
 583  *
 584  */
 585
 586 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 587 {
 588         struct inode *inode;
 589         int retval = -EOPNOTSUPP;
 590         struct p9_fid *v9fid, *dfid;
 591         struct v9fs_session_info *v9ses;
 592
 593         p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 594                  dir, dentry, flags);
 595
 596         v9ses = v9fs_inode2v9ses(dir);
 597         inode = d_inode(dentry);
 598         dfid = v9fs_fid_lookup(dentry->d_parent);
 599         if (IS_ERR(dfid)) {
 600                 retval = PTR_ERR(dfid);
 601                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 602                 return retval;
 603         }
 604         if (v9fs_proto_dotl(v9ses))
 605                 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 606                                             v9fs_at_to_dotl_flags(flags));
 607         if (retval == -EOPNOTSUPP) {
 608                 /* Try the one based on path */
 609                 v9fid = v9fs_fid_clone(dentry);
 610                 if (IS_ERR(v9fid))
 611                         return PTR_ERR(v9fid);
 612                 retval = p9_client_remove(v9fid);
 613         }
 614         if (!retval) {
 615                 /*
 616                  * directories on unlink should have zero
 617                  * link count
 618                  */
 619                 if (flags & AT_REMOVEDIR) {
 620                         clear_nlink(inode);
 621                         drop_nlink(dir);
 622                 } else
 623                         drop_nlink(inode);
 624
 625                 v9fs_invalidate_inode_attr(inode);
 626                 v9fs_invalidate_inode_attr(dir);
 627         }
 628         return retval;
 629 }
 630
 631 /**
 632  * v9fs_create - Create a file
 633  * @v9ses: session information
 634  * @dir: directory that dentry is being created in
 635  * @dentry:  dentry that is being created
 636  * @extension: 9p2000.u extension string to support devices, etc.
 637  * @perm: create permissions
 638  * @mode: open mode
 639  *
 640  */
 641 static struct p9_fid *
 642 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 643                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 644 {
 645         int err;
 646         char *name;
 647         struct p9_fid *dfid, *ofid, *fid;
 648         struct inode *inode;
 649
 650         p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 651
 652         err = 0;
 653         ofid = NULL;
 654         fid = NULL;
 655         name = (char *) dentry->d_name.name;
 656         dfid = v9fs_fid_lookup(dentry->d_parent);
 657         if (IS_ERR(dfid)) {
 658                 err = PTR_ERR(dfid);
 659                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 660                 return ERR_PTR(err);
 661         }
 662
 663         /* clone a fid to use for creation */
 664         ofid = p9_client_walk(dfid, 0, NULL, 1);
 665         if (IS_ERR(ofid)) {
 666                 err = PTR_ERR(ofid);
 667                 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 668                 return ERR_PTR(err);
 669         }
 670
 671         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 672         if (err < 0) {
 673                 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 674                 goto error;
 675         }
 676
 677         if (!(perm & P9_DMLINK)) {
 678                 /* now walk from the parent so we can get unopened fid */
 679                 fid = p9_client_walk(dfid, 1, &name, 1);
 680                 if (IS_ERR(fid)) {
 681                         err = PTR_ERR(fid);
 682                         p9_debug(P9_DEBUG_VFS,
 683                                    "p9_client_walk failed %d\n", err);
 684                         fid = NULL;
 685                         goto error;
 686                 }
 687                 /*
 688                  * instantiate inode and assign the unopened fid to the dentry
 689                  */
 690                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 691                 if (IS_ERR(inode)) {
 692                         err = PTR_ERR(inode);
 693                         p9_debug(P9_DEBUG_VFS,
 694                                    "inode creation failed %d\n", err);
 695                         goto error;
 696                 }
 697                 v9fs_fid_add(dentry, fid);
 698                 d_instantiate(dentry, inode);
 699         }
 700         return ofid;
 701 error:
 702         if (ofid)
 703                 p9_client_clunk(ofid);
 704
 705         if (fid)
 706                 p9_client_clunk(fid);
 707
 708         return ERR_PTR(err);
 709 }
 710
 711 /**
 712  * v9fs_vfs_create - VFS hook to create a regular file
 713  *
 714  * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 715  * for mknod(2).
 716  *
 717  * @dir: directory inode that is being created
 718  * @dentry:  dentry that is being deleted
 719  * @mode: create permissions
 720  *
 721  */
 722
 723 static int
 724 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 725                 bool excl)
 726 {
 727         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 728         u32 perm = unixmode2p9mode(v9ses, mode);
 729         struct p9_fid *fid;
 730
 731         /* P9_OEXCL? */
 732         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 733         if (IS_ERR(fid))
 734                 return PTR_ERR(fid);
 735
 736         v9fs_invalidate_inode_attr(dir);
 737         p9_client_clunk(fid);
 738
 739         return 0;
 740 }
 741
 742 /**
 743  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 744  * @dir:  inode that is being unlinked
 745  * @dentry: dentry that is being unlinked
 746  * @mode: mode for new directory
 747  *
 748  */
 749
 750 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 751 {
 752         int err;
 753         u32 perm;
 754         struct p9_fid *fid;
 755         struct v9fs_session_info *v9ses;
 756
 757         p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry);
 758         err = 0;
 759         v9ses = v9fs_inode2v9ses(dir);
 760         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 761         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 762         if (IS_ERR(fid)) {
 763                 err = PTR_ERR(fid);
 764                 fid = NULL;
 765         } else {
 766                 inc_nlink(dir);
 767                 v9fs_invalidate_inode_attr(dir);
 768         }
 769
 770         if (fid)
 771                 p9_client_clunk(fid);
 772
 773         return err;
 774 }
 775
 776 /**
 777  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 778  * @dir:  inode that is being walked from
 779  * @dentry: dentry that is being walked to?
 780  * @flags: lookup flags (unused)
 781  *
 782  */
 783
 784 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 785                                       unsigned int flags)
 786 {
 787         struct dentry *res;
 788         struct v9fs_session_info *v9ses;
 789         struct p9_fid *dfid, *fid;
 790         struct inode *inode;
 791         char *name;
 792
 793         p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n",
 794                  dir, dentry, dentry, flags);
 795
 796         if (dentry->d_name.len > NAME_MAX)
 797                 return ERR_PTR(-ENAMETOOLONG);
 798
 799         v9ses = v9fs_inode2v9ses(dir);
 800         /* We can walk d_parent because we hold the dir->i_mutex */
 801         dfid = v9fs_fid_lookup(dentry->d_parent);
 802         if (IS_ERR(dfid))
 803                 return ERR_CAST(dfid);
 804
 805         name = (char *) dentry->d_name.name;
 806         fid = p9_client_walk(dfid, 1, &name, 1);
 807         if (IS_ERR(fid)) {
 808                 if (fid == ERR_PTR(-ENOENT)) {
 809                         d_add(dentry, NULL);
 810                         return NULL;
 811                 }
 812                 return ERR_CAST(fid);
 813         }
 814         /*
 815          * Make sure we don't use a wrong inode due to parallel
 816          * unlink. For cached mode create calls request for new
 817          * inode. But with cache disabled, lookup should do this.
 818          */
 819         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 820                 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 821         else
 822                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 823         if (IS_ERR(inode)) {
 824                 p9_client_clunk(fid);
 825                 return ERR_CAST(inode);
 826         }
 827         /*
 828          * If we had a rename on the server and a parallel lookup
 829          * for the new name, then make sure we instantiate with
 830          * the new name. ie look up for a/b, while on server somebody
 831          * moved b under k and client parallely did a lookup for
 832          * k/b.
 833          */
 834         res = d_splice_alias(inode, dentry);
 835         if (!res)
 836                 v9fs_fid_add(dentry, fid);
 837         else if (!IS_ERR(res))
 838                 v9fs_fid_add(res, fid);
 839         else
 840                 p9_client_clunk(fid);
 841         return res;
 842 }
 843
 844 static int
 845 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 846                      struct file *file, unsigned flags, umode_t mode,
 847                      int *opened)
 848 {
 849         int err;
 850         u32 perm;
 851         struct v9fs_inode *v9inode;
 852         struct v9fs_session_info *v9ses;
 853         struct p9_fid *fid, *inode_fid;
 854         struct dentry *res = NULL;
 855
 856         if (d_unhashed(dentry)) {
 857                 res = v9fs_vfs_lookup(dir, dentry, 0);
 858                 if (IS_ERR(res))
 859                         return PTR_ERR(res);
 860
 861                 if (res)
 862                         dentry = res;
 863         }
 864
 865         /* Only creates */
 866         if (!(flags & O_CREAT) || d_really_is_positive(dentry))
 867                 return finish_no_open(file, res);
 868
 869         err = 0;
 870
 871         v9ses = v9fs_inode2v9ses(dir);
 872         perm = unixmode2p9mode(v9ses, mode);
 873         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 874                                 v9fs_uflags2omode(flags,
 875                                                 v9fs_proto_dotu(v9ses)));
 876         if (IS_ERR(fid)) {
 877                 err = PTR_ERR(fid);
 878                 fid = NULL;
 879                 goto error;
 880         }
 881
 882         v9fs_invalidate_inode_attr(dir);
 883         v9inode = V9FS_I(d_inode(dentry));
 884         mutex_lock(&v9inode->v_mutex);
 885         if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) &&
 886             !v9inode->writeback_fid &&
 887             ((flags & O_ACCMODE) != O_RDONLY)) {
 888                 /*
 889                  * clone a fid and add it to writeback_fid
 890                  * we do it during open time instead of
 891                  * page dirty time via write_begin/page_mkwrite
 892                  * because we want write after unlink usecase
 893                  * to work.
 894                  */
 895                 inode_fid = v9fs_writeback_fid(dentry);
 896                 if (IS_ERR(inode_fid)) {
 897                         err = PTR_ERR(inode_fid);
 898                         mutex_unlock(&v9inode->v_mutex);
 899                         goto error;
 900                 }
 901                 v9inode->writeback_fid = (void *) inode_fid;
 902         }
 903         mutex_unlock(&v9inode->v_mutex);
 904         err = finish_open(file, dentry, generic_file_open, opened);
 905         if (err)
 906                 goto error;
 907
 908         file->private_data = fid;
 909         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 910                 v9fs_cache_inode_set_cookie(d_inode(dentry), file);
 911
 912         *opened |= FILE_CREATED;
 913 out:
 914         dput(res);
 915         return err;
 916
 917 error:
 918         if (fid)
 919                 p9_client_clunk(fid);
 920         goto out;
 921 }
 922
 923 /**
 924  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 925  * @i:  inode that is being unlinked
 926  * @d: dentry that is being unlinked
 927  *
 928  */
 929
 930 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 931 {
 932         return v9fs_remove(i, d, 0);
 933 }
 934
 935 /**
 936  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 937  * @i:  inode that is being unlinked
 938  * @d: dentry that is being unlinked
 939  *
 940  */
 941
 942 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 943 {
 944         return v9fs_remove(i, d, AT_REMOVEDIR);
 945 }
 946
 947 /**
 948  * v9fs_vfs_rename - VFS hook to rename an inode
 949  * @old_dir:  old dir inode
 950  * @old_dentry: old dentry
 951  * @new_dir: new dir inode
 952  * @new_dentry: new dentry
 953  *
 954  */
 955
 956 int
 957 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 958                 struct inode *new_dir, struct dentry *new_dentry)
 959 {
 960         int retval;
 961         struct inode *old_inode;
 962         struct inode *new_inode;
 963         struct v9fs_session_info *v9ses;
 964         struct p9_fid *oldfid;
 965         struct p9_fid *olddirfid;
 966         struct p9_fid *newdirfid;
 967         struct p9_wstat wstat;
 968
 969         p9_debug(P9_DEBUG_VFS, "\n");
 970         retval = 0;
 971         old_inode = d_inode(old_dentry);
 972         new_inode = d_inode(new_dentry);
 973         v9ses = v9fs_inode2v9ses(old_inode);
 974         oldfid = v9fs_fid_lookup(old_dentry);
 975         if (IS_ERR(oldfid))
 976                 return PTR_ERR(oldfid);
 977
 978         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 979         if (IS_ERR(olddirfid)) {
 980                 retval = PTR_ERR(olddirfid);
 981                 goto done;
 982         }
 983
 984         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 985         if (IS_ERR(newdirfid)) {
 986                 retval = PTR_ERR(newdirfid);
 987                 goto clunk_olddir;
 988         }
 989
 990         down_write(&v9ses->rename_sem);
 991         if (v9fs_proto_dotl(v9ses)) {
 992                 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 993                                             newdirfid, new_dentry->d_name.name);
 994                 if (retval == -EOPNOTSUPP)
 995                         retval = p9_client_rename(oldfid, newdirfid,
 996                                                   new_dentry->d_name.name);
 997                 if (retval != -EOPNOTSUPP)
 998                         goto clunk_newdir;
 999         }
1000         if (old_dentry->d_parent != new_dentry->d_parent) {
1001                 /*
1002                  * 9P .u can only handle file rename in the same directory
1003                  */
1004
1005                 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
1006                 retval = -EXDEV;
1007                 goto clunk_newdir;
1008         }
1009         v9fs_blank_wstat(&wstat);
1010         wstat.muid = v9ses->uname;
1011         wstat.name = (char *) new_dentry->d_name.name;
1012         retval = p9_client_wstat(oldfid, &wstat);
1013
1014 clunk_newdir:
1015         if (!retval) {
1016                 if (new_inode) {
1017                         if (S_ISDIR(new_inode->i_mode))
1018                                 clear_nlink(new_inode);
1019                         else
1020                                 drop_nlink(new_inode);
1021                 }
1022                 if (S_ISDIR(old_inode->i_mode)) {
1023                         if (!new_inode)
1024                                 inc_nlink(new_dir);
1025                         drop_nlink(old_dir);
1026                 }
1027                 v9fs_invalidate_inode_attr(old_inode);
1028                 v9fs_invalidate_inode_attr(old_dir);
1029                 v9fs_invalidate_inode_attr(new_dir);
1030
1031                 /* successful rename */
1032                 d_move(old_dentry, new_dentry);
1033         }
1034         up_write(&v9ses->rename_sem);
1035         p9_client_clunk(newdirfid);
1036
1037 clunk_olddir:
1038         p9_client_clunk(olddirfid);
1039
1040 done:
1041         return retval;
1042 }
1043
1044 /**
1045  * v9fs_vfs_getattr - retrieve file metadata
1046  * @mnt: mount information
1047  * @dentry: file to get attributes on
1048  * @stat: metadata structure to populate
1049  *
1050  */
1051
1052 static int
1053 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1054                  struct kstat *stat)
1055 {
1056         struct v9fs_session_info *v9ses;
1057         struct p9_fid *fid;
1058         struct p9_wstat *st;
1059
1060         p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1061         v9ses = v9fs_dentry2v9ses(dentry);
1062         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1063                 generic_fillattr(d_inode(dentry), stat);
1064                 return 0;
1065         }
1066         fid = v9fs_fid_lookup(dentry);
1067         if (IS_ERR(fid))
1068                 return PTR_ERR(fid);
1069
1070         st = p9_client_stat(fid);
1071         if (IS_ERR(st))
1072                 return PTR_ERR(st);
1073
1074         v9fs_stat2inode(st, d_inode(dentry), d_inode(dentry)->i_sb);
1075         generic_fillattr(d_inode(dentry), stat);
1076
1077         p9stat_free(st);
1078         kfree(st);
1079         return 0;
1080 }
1081
1082 /**
1083  * v9fs_vfs_setattr - set file metadata
1084  * @dentry: file whose metadata to set
1085  * @iattr: metadata assignment structure
1086  *
1087  */
1088
1089 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1090 {
1091         int retval;
1092         struct v9fs_session_info *v9ses;
1093         struct p9_fid *fid;
1094         struct p9_wstat wstat;
1095
1096         p9_debug(P9_DEBUG_VFS, "\n");
1097         retval = inode_change_ok(d_inode(dentry), iattr);
1098         if (retval)
1099                 return retval;
1100
1101         retval = -EPERM;
1102         v9ses = v9fs_dentry2v9ses(dentry);
1103         fid = v9fs_fid_lookup(dentry);
1104         if(IS_ERR(fid))
1105                 return PTR_ERR(fid);
1106
1107         v9fs_blank_wstat(&wstat);
1108         if (iattr->ia_valid & ATTR_MODE)
1109                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1110
1111         if (iattr->ia_valid & ATTR_MTIME)
1112                 wstat.mtime = iattr->ia_mtime.tv_sec;
1113
1114         if (iattr->ia_valid & ATTR_ATIME)
1115                 wstat.atime = iattr->ia_atime.tv_sec;
1116
1117         if (iattr->ia_valid & ATTR_SIZE)
1118                 wstat.length = iattr->ia_size;
1119
1120         if (v9fs_proto_dotu(v9ses)) {
1121                 if (iattr->ia_valid & ATTR_UID)
1122                         wstat.n_uid = iattr->ia_uid;
1123
1124                 if (iattr->ia_valid & ATTR_GID)
1125                         wstat.n_gid = iattr->ia_gid;
1126         }
1127
1128         /* Write all dirty data */
1129         if (d_is_reg(dentry))
1130                 filemap_write_and_wait(d_inode(dentry)->i_mapping);
1131
1132         retval = p9_client_wstat(fid, &wstat);
1133         if (retval < 0)
1134                 return retval;
1135
1136         if ((iattr->ia_valid & ATTR_SIZE) &&
1137             iattr->ia_size != i_size_read(d_inode(dentry)))
1138                 truncate_setsize(d_inode(dentry), iattr->ia_size);
1139
1140         v9fs_invalidate_inode_attr(d_inode(dentry));
1141
1142         setattr_copy(d_inode(dentry), iattr);
1143         mark_inode_dirty(d_inode(dentry));
1144         return 0;
1145 }
1146
1147 /**
1148  * v9fs_stat2inode - populate an inode structure with mistat info
1149  * @stat: Plan 9 metadata (mistat) structure
1150  * @inode: inode to populate
1151  * @sb: superblock of filesystem
1152  *
1153  */
1154
1155 void
1156 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1157         struct super_block *sb)
1158 {
1159         umode_t mode;
1160         char ext[32];
1161         char tag_name[14];
1162         unsigned int i_nlink;
1163         struct v9fs_session_info *v9ses = sb->s_fs_info;
1164         struct v9fs_inode *v9inode = V9FS_I(inode);
1165
1166         set_nlink(inode, 1);
1167
1168         inode->i_atime.tv_sec = stat->atime;
1169         inode->i_mtime.tv_sec = stat->mtime;
1170         inode->i_ctime.tv_sec = stat->mtime;
1171
1172         inode->i_uid = v9ses->dfltuid;
1173         inode->i_gid = v9ses->dfltgid;
1174
1175         if (v9fs_proto_dotu(v9ses)) {
1176                 inode->i_uid = stat->n_uid;
1177                 inode->i_gid = stat->n_gid;
1178         }
1179         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1180                 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1181                         /*
1182                          * Hadlink support got added later to
1183                          * to the .u extension. So there can be
1184                          * server out there that doesn't support
1185                          * this even with .u extension. So check
1186                          * for non NULL stat->extension
1187                          */
1188                         strlcpy(ext, stat->extension, sizeof(ext));
1189                         /* HARDLINKCOUNT %u */
1190                         sscanf(ext, "%13s %u", tag_name, &i_nlink);
1191                         if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1192                                 set_nlink(inode, i_nlink);
1193                 }
1194         }
1195         mode = p9mode2perm(v9ses, stat);
1196         mode |= inode->i_mode & ~S_IALLUGO;
1197         inode->i_mode = mode;
1198         i_size_write(inode, stat->length);
1199
1200         /* not real number of blocks, but 512 byte ones ... */
1201         inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1202         v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1203 }
1204
1205 /**
1206  * v9fs_qid2ino - convert qid into inode number
1207  * @qid: qid to hash
1208  *
1209  * BUG: potential for inode number collisions?
1210  */
1211
1212 ino_t v9fs_qid2ino(struct p9_qid *qid)
1213 {
1214         u64 path = qid->path + 2;
1215         ino_t i = 0;
1216
1217         if (sizeof(ino_t) == sizeof(path))
1218                 memcpy(&i, &path, sizeof(ino_t));
1219         else
1220                 i = (ino_t) (path ^ (path >> 32));
1221
1222         return i;
1223 }
1224
1225 /**
1226  * v9fs_vfs_get_link - follow a symlink path
1227  * @dentry: dentry for symlink
1228  * @inode: inode for symlink
1229  * @done: delayed call for when we are done with the return value
1230  */
1231
1232 static const char *v9fs_vfs_get_link(struct dentry *dentry,
1233                                      struct inode *inode,
1234                                      struct delayed_call *done)
1235 {
1236         struct v9fs_session_info *v9ses;
1237         struct p9_fid *fid;
1238         struct p9_wstat *st;
1239         char *res;
1240
1241         if (!dentry)
1242                 return ERR_PTR(-ECHILD);
1243
1244         v9ses = v9fs_dentry2v9ses(dentry);
1245         fid = v9fs_fid_lookup(dentry);
1246         p9_debug(P9_DEBUG_VFS, "%pd\n", dentry);
1247
1248         if (IS_ERR(fid))
1249                 return ERR_CAST(fid);
1250
1251         if (!v9fs_proto_dotu(v9ses))
1252                 return ERR_PTR(-EBADF);
1253
1254         st = p9_client_stat(fid);
1255         if (IS_ERR(st))
1256                 return ERR_CAST(st);
1257
1258         if (!(st->mode & P9_DMSYMLINK)) {
1259                 p9stat_free(st);
1260                 kfree(st);
1261                 return ERR_PTR(-EINVAL);
1262         }
1263         res = st->extension;
1264         st->extension = NULL;
1265         if (strlen(res) >= PATH_MAX)
1266                 res[PATH_MAX - 1] = '\0';
1267
1268         p9stat_free(st);
1269         kfree(st);
1270         set_delayed_call(done, kfree_link, res);
1271         return res;
1272 }
1273
1274 /**
1275  * v9fs_vfs_mkspecial - create a special file
1276  * @dir: inode to create special file in
1277  * @dentry: dentry to create
1278  * @perm: mode to create special file
1279  * @extension: 9p2000.u format extension string representing special file
1280  *
1281  */
1282
1283 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1284         u32 perm, const char *extension)
1285 {
1286         struct p9_fid *fid;
1287         struct v9fs_session_info *v9ses;
1288
1289         v9ses = v9fs_inode2v9ses(dir);
1290         if (!v9fs_proto_dotu(v9ses)) {
1291                 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1292                 return -EPERM;
1293         }
1294
1295         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1296                                                                 P9_OREAD);
1297         if (IS_ERR(fid))
1298                 return PTR_ERR(fid);
1299
1300         v9fs_invalidate_inode_attr(dir);
1301         p9_client_clunk(fid);
1302         return 0;
1303 }
1304
1305 /**
1306  * v9fs_vfs_symlink - helper function to create symlinks
1307  * @dir: directory inode containing symlink
1308  * @dentry: dentry for symlink
1309  * @symname: symlink data
1310  *
1311  * See Also: 9P2000.u RFC for more information
1312  *
1313  */
1314
1315 static int
1316 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1317 {
1318         p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n",
1319                  dir->i_ino, dentry, symname);
1320
1321         return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1322 }
1323
1324 #define U32_MAX_DIGITS 10
1325
1326 /**
1327  * v9fs_vfs_link - create a hardlink
1328  * @old_dentry: dentry for file to link to
1329  * @dir: inode destination for new link
1330  * @dentry: dentry for link
1331  *
1332  */
1333
1334 static int
1335 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1336               struct dentry *dentry)
1337 {
1338         int retval;
1339         char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */
1340         struct p9_fid *oldfid;
1341
1342         p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n",
1343                  dir->i_ino, dentry, old_dentry);
1344
1345         oldfid = v9fs_fid_clone(old_dentry);
1346         if (IS_ERR(oldfid))
1347                 return PTR_ERR(oldfid);
1348
1349         sprintf(name, "%d\n", oldfid->fid);
1350         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1351         if (!retval) {
1352                 v9fs_refresh_inode(oldfid, d_inode(old_dentry));
1353                 v9fs_invalidate_inode_attr(dir);
1354         }
1355         p9_client_clunk(oldfid);
1356         return retval;
1357 }
1358
1359 /**
1360  * v9fs_vfs_mknod - create a special file
1361  * @dir: inode destination for new link
1362  * @dentry: dentry for file
1363  * @mode: mode for creation
1364  * @rdev: device associated with special file
1365  *
1366  */
1367
1368 static int
1369 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1370 {
1371         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1372         int retval;
1373         char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1];
1374         u32 perm;
1375
1376         p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n",
1377                  dir->i_ino, dentry, mode,
1378                  MAJOR(rdev), MINOR(rdev));
1379
1380         /* build extension */
1381         if (S_ISBLK(mode))
1382                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1383         else if (S_ISCHR(mode))
1384                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1385         else
1386                 *name = 0;
1387
1388         perm = unixmode2p9mode(v9ses, mode);
1389         retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1390
1391         return retval;
1392 }
1393
1394 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1395 {
1396         int umode;
1397         dev_t rdev;
1398         loff_t i_size;
1399         struct p9_wstat *st;
1400         struct v9fs_session_info *v9ses;
1401
1402         v9ses = v9fs_inode2v9ses(inode);
1403         st = p9_client_stat(fid);
1404         if (IS_ERR(st))
1405                 return PTR_ERR(st);
1406         /*
1407          * Don't update inode if the file type is different
1408          */
1409         umode = p9mode2unixmode(v9ses, st, &rdev);
1410         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1411                 goto out;
1412
1413         spin_lock(&inode->i_lock);
1414         /*
1415          * We don't want to refresh inode->i_size,
1416          * because we may have cached data
1417          */
1418         i_size = inode->i_size;
1419         v9fs_stat2inode(st, inode, inode->i_sb);
1420         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
1421                 inode->i_size = i_size;
1422         spin_unlock(&inode->i_lock);
1423 out:
1424         p9stat_free(st);
1425         kfree(st);
1426         return 0;
1427 }
1428
1429 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1430         .create = v9fs_vfs_create,
1431         .lookup = v9fs_vfs_lookup,
1432         .atomic_open = v9fs_vfs_atomic_open,
1433         .symlink = v9fs_vfs_symlink,
1434         .link = v9fs_vfs_link,
1435         .unlink = v9fs_vfs_unlink,
1436         .mkdir = v9fs_vfs_mkdir,
1437         .rmdir = v9fs_vfs_rmdir,
1438         .mknod = v9fs_vfs_mknod,
1439         .rename = v9fs_vfs_rename,
1440         .getattr = v9fs_vfs_getattr,
1441         .setattr = v9fs_vfs_setattr,
1442 };
1443
1444 static const struct inode_operations v9fs_dir_inode_operations = {
1445         .create = v9fs_vfs_create,
1446         .lookup = v9fs_vfs_lookup,
1447         .atomic_open = v9fs_vfs_atomic_open,
1448         .unlink = v9fs_vfs_unlink,
1449         .mkdir = v9fs_vfs_mkdir,
1450         .rmdir = v9fs_vfs_rmdir,
1451         .mknod = v9fs_vfs_mknod,
1452         .rename = v9fs_vfs_rename,
1453         .getattr = v9fs_vfs_getattr,
1454         .setattr = v9fs_vfs_setattr,
1455 };
1456
1457 static const struct inode_operations v9fs_file_inode_operations = {
1458         .getattr = v9fs_vfs_getattr,
1459         .setattr = v9fs_vfs_setattr,
1460 };
1461
1462 static const struct inode_operations v9fs_symlink_inode_operations = {
1463         .readlink = generic_readlink,
1464         .get_link = v9fs_vfs_get_link,
1465         .getattr = v9fs_vfs_getattr,
1466         .setattr = v9fs_vfs_setattr,
1467 };
1468