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                 strncpy(ext, stat->extension, sizeof(ext));
 150                 sscanf(ext, "%c %u %u", &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 (uflags & O_TRUNC)
 196                 ret |= P9_OTRUNC;
 197
 198         if (extended) {
 199                 if (uflags & O_EXCL)
 200                         ret |= P9_OEXCL;
 201
 202                 if (uflags & O_APPEND)
 203                         ret |= P9_OAPPEND;
 204         }
 205
 206         return ret;
 207 }
 208
 209 /**
 210  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 211  * @wstat: structure to initialize
 212  *
 213  */
 214
 215 void
 216 v9fs_blank_wstat(struct p9_wstat *wstat)
 217 {
 218         wstat->type = ~0;
 219         wstat->dev = ~0;
 220         wstat->qid.type = ~0;
 221         wstat->qid.version = ~0;
 222         *((long long *)&wstat->qid.path) = ~0;
 223         wstat->mode = ~0;
 224         wstat->atime = ~0;
 225         wstat->mtime = ~0;
 226         wstat->length = ~0;
 227         wstat->name = NULL;
 228         wstat->uid = NULL;
 229         wstat->gid = NULL;
 230         wstat->muid = NULL;
 231         wstat->n_uid = ~0;
 232         wstat->n_gid = ~0;
 233         wstat->n_muid = ~0;
 234         wstat->extension = NULL;
 235 }
 236
 237 /**
 238  * v9fs_alloc_inode - helper function to allocate an inode
 239  *
 240  */
 241 struct inode *v9fs_alloc_inode(struct super_block *sb)
 242 {
 243         struct v9fs_inode *v9inode;
 244         v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 245                                                         GFP_KERNEL);
 246         if (!v9inode)
 247                 return NULL;
 248 #ifdef CONFIG_9P_FSCACHE
 249         v9inode->fscache = NULL;
 250         spin_lock_init(&v9inode->fscache_lock);
 251 #endif
 252         v9inode->writeback_fid = NULL;
 253         v9inode->cache_validity = 0;
 254         mutex_init(&v9inode->v_mutex);
 255         return &v9inode->vfs_inode;
 256 }
 257
 258 /**
 259  * v9fs_destroy_inode - destroy an inode
 260  *
 261  */
 262
 263 static void v9fs_i_callback(struct rcu_head *head)
 264 {
 265         struct inode *inode = container_of(head, struct inode, i_rcu);
 266         kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 267 }
 268
 269 void v9fs_destroy_inode(struct inode *inode)
 270 {
 271         call_rcu(&inode->i_rcu, v9fs_i_callback);
 272 }
 273
 274 int v9fs_init_inode(struct v9fs_session_info *v9ses,
 275                     struct inode *inode, umode_t mode, dev_t rdev)
 276 {
 277         int err = 0;
 278
 279         inode_init_owner(inode, NULL, mode);
 280         inode->i_blocks = 0;
 281         inode->i_rdev = rdev;
 282         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 283         inode->i_mapping->a_ops = &v9fs_addr_operations;
 284
 285         switch (mode & S_IFMT) {
 286         case S_IFIFO:
 287         case S_IFBLK:
 288         case S_IFCHR:
 289         case S_IFSOCK:
 290                 if (v9fs_proto_dotl(v9ses)) {
 291                         inode->i_op = &v9fs_file_inode_operations_dotl;
 292                 } else if (v9fs_proto_dotu(v9ses)) {
 293                         inode->i_op = &v9fs_file_inode_operations;
 294                 } else {
 295                         p9_debug(P9_DEBUG_ERROR,
 296                                  "special files without extended mode\n");
 297                         err = -EINVAL;
 298                         goto error;
 299                 }
 300                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 301                 break;
 302         case S_IFREG:
 303                 if (v9fs_proto_dotl(v9ses)) {
 304                         inode->i_op = &v9fs_file_inode_operations_dotl;
 305                         if (v9ses->cache)
 306                                 inode->i_fop =
 307                                         &v9fs_cached_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)
 313                                 inode->i_fop = &v9fs_cached_file_operations;
 314                         else
 315                                 inode->i_fop = &v9fs_file_operations;
 316                 }
 317
 318                 break;
 319         case S_IFLNK:
 320                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 321                         p9_debug(P9_DEBUG_ERROR,
 322                                  "extended modes used with legacy protocol\n");
 323                         err = -EINVAL;
 324                         goto error;
 325                 }
 326
 327                 if (v9fs_proto_dotl(v9ses))
 328                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
 329                 else
 330                         inode->i_op = &v9fs_symlink_inode_operations;
 331
 332                 break;
 333         case S_IFDIR:
 334                 inc_nlink(inode);
 335                 if (v9fs_proto_dotl(v9ses))
 336                         inode->i_op = &v9fs_dir_inode_operations_dotl;
 337                 else if (v9fs_proto_dotu(v9ses))
 338                         inode->i_op = &v9fs_dir_inode_operations_dotu;
 339                 else
 340                         inode->i_op = &v9fs_dir_inode_operations;
 341
 342                 if (v9fs_proto_dotl(v9ses))
 343                         inode->i_fop = &v9fs_dir_operations_dotl;
 344                 else
 345                         inode->i_fop = &v9fs_dir_operations;
 346
 347                 break;
 348         default:
 349                 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 350                          mode, mode & S_IFMT);
 351                 err = -EINVAL;
 352                 goto error;
 353         }
 354 error:
 355         return err;
 356
 357 }
 358
 359 /**
 360  * v9fs_get_inode - helper function to setup an inode
 361  * @sb: superblock
 362  * @mode: mode to setup inode with
 363  *
 364  */
 365
 366 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 367 {
 368         int err;
 369         struct inode *inode;
 370         struct v9fs_session_info *v9ses = sb->s_fs_info;
 371
 372         p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 373
 374         inode = new_inode(sb);
 375         if (!inode) {
 376                 pr_warn("%s (%d): Problem allocating inode\n",
 377                         __func__, task_pid_nr(current));
 378                 return ERR_PTR(-ENOMEM);
 379         }
 380         err = v9fs_init_inode(v9ses, inode, mode, rdev);
 381         if (err) {
 382                 iput(inode);
 383                 return ERR_PTR(err);
 384         }
 385         return inode;
 386 }
 387
 388 /*
 389 static struct v9fs_fid*
 390 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 391 {
 392         int err;
 393         int nfid;
 394         struct v9fs_fid *ret;
 395         struct v9fs_fcall *fcall;
 396
 397         nfid = v9fs_get_idpool(&v9ses->fidpool);
 398         if (nfid < 0) {
 399                 eprintk(KERN_WARNING, "no free fids available\n");
 400                 return ERR_PTR(-ENOSPC);
 401         }
 402
 403         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 404                 &fcall);
 405
 406         if (err < 0) {
 407                 if (fcall && fcall->id == RWALK)
 408                         goto clunk_fid;
 409
 410                 PRINT_FCALL_ERROR("walk error", fcall);
 411                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 412                 goto error;
 413         }
 414
 415         kfree(fcall);
 416         fcall = NULL;
 417         ret = v9fs_fid_create(v9ses, nfid);
 418         if (!ret) {
 419                 err = -ENOMEM;
 420                 goto clunk_fid;
 421         }
 422
 423         err = v9fs_fid_insert(ret, dentry);
 424         if (err < 0) {
 425                 v9fs_fid_destroy(ret);
 426                 goto clunk_fid;
 427         }
 428
 429         return ret;
 430
 431 clunk_fid:
 432         v9fs_t_clunk(v9ses, nfid);
 433
 434 error:
 435         kfree(fcall);
 436         return ERR_PTR(err);
 437 }
 438 */
 439
 440
 441 /**
 442  * v9fs_clear_inode - release an inode
 443  * @inode: inode to release
 444  *
 445  */
 446 void v9fs_evict_inode(struct inode *inode)
 447 {
 448         struct v9fs_inode *v9inode = V9FS_I(inode);
 449
 450         truncate_inode_pages(inode->i_mapping, 0);
 451         clear_inode(inode);
 452         filemap_fdatawrite(inode->i_mapping);
 453
 454 #ifdef CONFIG_9P_FSCACHE
 455         v9fs_cache_inode_put_cookie(inode);
 456 #endif
 457         /* clunk the fid stashed in writeback_fid */
 458         if (v9inode->writeback_fid) {
 459                 p9_client_clunk(v9inode->writeback_fid);
 460                 v9inode->writeback_fid = NULL;
 461         }
 462 }
 463
 464 static int v9fs_test_inode(struct inode *inode, void *data)
 465 {
 466         int umode;
 467         dev_t rdev;
 468         struct v9fs_inode *v9inode = V9FS_I(inode);
 469         struct p9_wstat *st = (struct p9_wstat *)data;
 470         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 471
 472         umode = p9mode2unixmode(v9ses, st, &rdev);
 473         /* don't match inode of different type */
 474         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 475                 return 0;
 476
 477         /* compare qid details */
 478         if (memcmp(&v9inode->qid.version,
 479                    &st->qid.version, sizeof(v9inode->qid.version)))
 480                 return 0;
 481
 482         if (v9inode->qid.type != st->qid.type)
 483                 return 0;
 484         return 1;
 485 }
 486
 487 static int v9fs_test_new_inode(struct inode *inode, void *data)
 488 {
 489         return 0;
 490 }
 491
 492 static int v9fs_set_inode(struct inode *inode,  void *data)
 493 {
 494         struct v9fs_inode *v9inode = V9FS_I(inode);
 495         struct p9_wstat *st = (struct p9_wstat *)data;
 496
 497         memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 498         return 0;
 499 }
 500
 501 static struct inode *v9fs_qid_iget(struct super_block *sb,
 502                                    struct p9_qid *qid,
 503                                    struct p9_wstat *st,
 504                                    int new)
 505 {
 506         dev_t rdev;
 507         int retval;
 508         umode_t umode;
 509         unsigned long i_ino;
 510         struct inode *inode;
 511         struct v9fs_session_info *v9ses = sb->s_fs_info;
 512         int (*test)(struct inode *, void *);
 513
 514         if (new)
 515                 test = v9fs_test_new_inode;
 516         else
 517                 test = v9fs_test_inode;
 518
 519         i_ino = v9fs_qid2ino(qid);
 520         inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 521         if (!inode)
 522                 return ERR_PTR(-ENOMEM);
 523         if (!(inode->i_state & I_NEW))
 524                 return inode;
 525         /*
 526          * initialize the inode with the stat info
 527          * FIXME!! we may need support for stale inodes
 528          * later.
 529          */
 530         inode->i_ino = i_ino;
 531         umode = p9mode2unixmode(v9ses, st, &rdev);
 532         retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 533         if (retval)
 534                 goto error;
 535
 536         v9fs_stat2inode(st, inode, sb);
 537 #ifdef CONFIG_9P_FSCACHE
 538         v9fs_cache_inode_get_cookie(inode);
 539 #endif
 540         unlock_new_inode(inode);
 541         return inode;
 542 error:
 543         unlock_new_inode(inode);
 544         iput(inode);
 545         return ERR_PTR(retval);
 546
 547 }
 548
 549 struct inode *
 550 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 551                     struct super_block *sb, int new)
 552 {
 553         struct p9_wstat *st;
 554         struct inode *inode = NULL;
 555
 556         st = p9_client_stat(fid);
 557         if (IS_ERR(st))
 558                 return ERR_CAST(st);
 559
 560         inode = v9fs_qid_iget(sb, &st->qid, st, new);
 561         p9stat_free(st);
 562         kfree(st);
 563         return inode;
 564 }
 565
 566 /**
 567  * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 568  * plan 9 AT flag.
 569  * @flags: flags to convert
 570  */
 571 static int v9fs_at_to_dotl_flags(int flags)
 572 {
 573         int rflags = 0;
 574         if (flags & AT_REMOVEDIR)
 575                 rflags |= P9_DOTL_AT_REMOVEDIR;
 576         return rflags;
 577 }
 578
 579 /**
 580  * v9fs_remove - helper function to remove files and directories
 581  * @dir: directory inode that is being deleted
 582  * @dentry:  dentry that is being deleted
 583  * @rmdir: removing a directory
 584  *
 585  */
 586
 587 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 588 {
 589         struct inode *inode;
 590         int retval = -EOPNOTSUPP;
 591         struct p9_fid *v9fid, *dfid;
 592         struct v9fs_session_info *v9ses;
 593
 594         p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 595                  dir, dentry, flags);
 596
 597         v9ses = v9fs_inode2v9ses(dir);
 598         inode = dentry->d_inode;
 599         dfid = v9fs_fid_lookup(dentry->d_parent);
 600         if (IS_ERR(dfid)) {
 601                 retval = PTR_ERR(dfid);
 602                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 603                 return retval;
 604         }
 605         if (v9fs_proto_dotl(v9ses))
 606                 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 607                                             v9fs_at_to_dotl_flags(flags));
 608         if (retval == -EOPNOTSUPP) {
 609                 /* Try the one based on path */
 610                 v9fid = v9fs_fid_clone(dentry);
 611                 if (IS_ERR(v9fid))
 612                         return PTR_ERR(v9fid);
 613                 retval = p9_client_remove(v9fid);
 614         }
 615         if (!retval) {
 616                 /*
 617                  * directories on unlink should have zero
 618                  * link count
 619                  */
 620                 if (flags & AT_REMOVEDIR) {
 621                         clear_nlink(inode);
 622                         drop_nlink(dir);
 623                 } else
 624                         drop_nlink(inode);
 625
 626                 v9fs_invalidate_inode_attr(inode);
 627                 v9fs_invalidate_inode_attr(dir);
 628         }
 629         return retval;
 630 }
 631
 632 /**
 633  * v9fs_create - Create a file
 634  * @v9ses: session information
 635  * @dir: directory that dentry is being created in
 636  * @dentry:  dentry that is being created
 637  * @extension: 9p2000.u extension string to support devices, etc.
 638  * @perm: create permissions
 639  * @mode: open mode
 640  *
 641  */
 642 static struct p9_fid *
 643 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 644                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 645 {
 646         int err;
 647         char *name;
 648         struct p9_fid *dfid, *ofid, *fid;
 649         struct inode *inode;
 650
 651         p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 652
 653         err = 0;
 654         ofid = NULL;
 655         fid = NULL;
 656         name = (char *) dentry->d_name.name;
 657         dfid = v9fs_fid_lookup(dentry->d_parent);
 658         if (IS_ERR(dfid)) {
 659                 err = PTR_ERR(dfid);
 660                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 661                 return ERR_PTR(err);
 662         }
 663
 664         /* clone a fid to use for creation */
 665         ofid = p9_client_walk(dfid, 0, NULL, 1);
 666         if (IS_ERR(ofid)) {
 667                 err = PTR_ERR(ofid);
 668                 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 669                 return ERR_PTR(err);
 670         }
 671
 672         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 673         if (err < 0) {
 674                 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 675                 goto error;
 676         }
 677
 678         if (!(perm & P9_DMLINK)) {
 679                 /* now walk from the parent so we can get unopened fid */
 680                 fid = p9_client_walk(dfid, 1, &name, 1);
 681                 if (IS_ERR(fid)) {
 682                         err = PTR_ERR(fid);
 683                         p9_debug(P9_DEBUG_VFS,
 684                                    "p9_client_walk failed %d\n", err);
 685                         fid = NULL;
 686                         goto error;
 687                 }
 688                 /*
 689                  * instantiate inode and assign the unopened fid to the dentry
 690                  */
 691                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 692                 if (IS_ERR(inode)) {
 693                         err = PTR_ERR(inode);
 694                         p9_debug(P9_DEBUG_VFS,
 695                                    "inode creation failed %d\n", err);
 696                         goto error;
 697                 }
 698                 err = v9fs_fid_add(dentry, fid);
 699                 if (err < 0)
 700                         goto error;
 701                 d_instantiate(dentry, inode);
 702         }
 703         return ofid;
 704 error:
 705         if (ofid)
 706                 p9_client_clunk(ofid);
 707
 708         if (fid)
 709                 p9_client_clunk(fid);
 710
 711         return ERR_PTR(err);
 712 }
 713
 714 /**
 715  * v9fs_vfs_create - VFS hook to create a regular file
 716  *
 717  * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 718  * for mknod(2).
 719  *
 720  * @dir: directory inode that is being created
 721  * @dentry:  dentry that is being deleted
 722  * @mode: create permissions
 723  *
 724  */
 725
 726 static int
 727 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 728                 struct nameidata *nd)
 729 {
 730         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 731         u32 perm = unixmode2p9mode(v9ses, mode);
 732         struct p9_fid *fid;
 733
 734         /* P9_OEXCL? */
 735         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 736         if (IS_ERR(fid))
 737                 return PTR_ERR(fid);
 738
 739         v9fs_invalidate_inode_attr(dir);
 740         p9_client_clunk(fid);
 741
 742         return 0;
 743 }
 744
 745 /**
 746  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 747  * @dir:  inode that is being unlinked
 748  * @dentry: dentry that is being unlinked
 749  * @mode: mode for new directory
 750  *
 751  */
 752
 753 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 754 {
 755         int err;
 756         u32 perm;
 757         struct p9_fid *fid;
 758         struct v9fs_session_info *v9ses;
 759
 760         p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 761         err = 0;
 762         v9ses = v9fs_inode2v9ses(dir);
 763         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 764         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 765         if (IS_ERR(fid)) {
 766                 err = PTR_ERR(fid);
 767                 fid = NULL;
 768         } else {
 769                 inc_nlink(dir);
 770                 v9fs_invalidate_inode_attr(dir);
 771         }
 772
 773         if (fid)
 774                 p9_client_clunk(fid);
 775
 776         return err;
 777 }
 778
 779 /**
 780  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 781  * @dir:  inode that is being walked from
 782  * @dentry: dentry that is being walked to?
 783  * @nameidata: path data
 784  *
 785  */
 786
 787 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 788                                       struct nameidata *nameidata)
 789 {
 790         struct dentry *res;
 791         struct super_block *sb;
 792         struct v9fs_session_info *v9ses;
 793         struct p9_fid *dfid, *fid;
 794         struct inode *inode;
 795         char *name;
 796         int result = 0;
 797
 798         p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 799                  dir, dentry->d_name.name, dentry, nameidata);
 800
 801         if (dentry->d_name.len > NAME_MAX)
 802                 return ERR_PTR(-ENAMETOOLONG);
 803
 804         sb = dir->i_sb;
 805         v9ses = v9fs_inode2v9ses(dir);
 806         /* We can walk d_parent because we hold the dir->i_mutex */
 807         dfid = v9fs_fid_lookup(dentry->d_parent);
 808         if (IS_ERR(dfid))
 809                 return ERR_CAST(dfid);
 810
 811         name = (char *) dentry->d_name.name;
 812         fid = p9_client_walk(dfid, 1, &name, 1);
 813         if (IS_ERR(fid)) {
 814                 result = PTR_ERR(fid);
 815                 if (result == -ENOENT) {
 816                         inode = NULL;
 817                         goto inst_out;
 818                 }
 819
 820                 return ERR_PTR(result);
 821         }
 822         /*
 823          * Make sure we don't use a wrong inode due to parallel
 824          * unlink. For cached mode create calls request for new
 825          * inode. But with cache disabled, lookup should do this.
 826          */
 827         if (v9ses->cache)
 828                 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 829         else
 830                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 831         if (IS_ERR(inode)) {
 832                 result = PTR_ERR(inode);
 833                 inode = NULL;
 834                 goto error;
 835         }
 836         result = v9fs_fid_add(dentry, fid);
 837         if (result < 0)
 838                 goto error_iput;
 839 inst_out:
 840         /*
 841          * If we had a rename on the server and a parallel lookup
 842          * for the new name, then make sure we instantiate with
 843          * the new name. ie look up for a/b, while on server somebody
 844          * moved b under k and client parallely did a lookup for
 845          * k/b.
 846          */
 847         res = d_materialise_unique(dentry, inode);
 848         if (!IS_ERR(res))
 849                 return res;
 850         result = PTR_ERR(res);
 851 error_iput:
 852         iput(inode);
 853 error:
 854         p9_client_clunk(fid);
 855
 856         return ERR_PTR(result);
 857 }
 858
 859 static int
 860 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 861                      struct file *file, unsigned flags, umode_t mode,
 862                      int *opened)
 863 {
 864         int err;
 865         u32 perm;
 866         struct v9fs_inode *v9inode;
 867         struct v9fs_session_info *v9ses;
 868         struct p9_fid *fid, *inode_fid;
 869         struct dentry *res = NULL;
 870
 871         if (d_unhashed(dentry)) {
 872                 res = v9fs_vfs_lookup(dir, dentry, NULL);
 873                 if (IS_ERR(res))
 874                         return PTR_ERR(res);
 875
 876                 if (res)
 877                         dentry = res;
 878         }
 879
 880         /* Only creates */
 881         if (!(flags & O_CREAT) || dentry->d_inode)
 882                 return finish_no_open(file, res);
 883
 884         err = 0;
 885         fid = NULL;
 886         v9ses = v9fs_inode2v9ses(dir);
 887         perm = unixmode2p9mode(v9ses, mode);
 888         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 889                                 v9fs_uflags2omode(flags,
 890                                                 v9fs_proto_dotu(v9ses)));
 891         if (IS_ERR(fid)) {
 892                 err = PTR_ERR(fid);
 893                 fid = NULL;
 894                 goto error;
 895         }
 896
 897         v9fs_invalidate_inode_attr(dir);
 898         v9inode = V9FS_I(dentry->d_inode);
 899         mutex_lock(&v9inode->v_mutex);
 900         if (v9ses->cache && !v9inode->writeback_fid &&
 901             ((flags & O_ACCMODE) != O_RDONLY)) {
 902                 /*
 903                  * clone a fid and add it to writeback_fid
 904                  * we do it during open time instead of
 905                  * page dirty time via write_begin/page_mkwrite
 906                  * because we want write after unlink usecase
 907                  * to work.
 908                  */
 909                 inode_fid = v9fs_writeback_fid(dentry);
 910                 if (IS_ERR(inode_fid)) {
 911                         err = PTR_ERR(inode_fid);
 912                         mutex_unlock(&v9inode->v_mutex);
 913                         goto error;
 914                 }
 915                 v9inode->writeback_fid = (void *) inode_fid;
 916         }
 917         mutex_unlock(&v9inode->v_mutex);
 918         err = finish_open(file, dentry, generic_file_open, opened);
 919         if (err)
 920                 goto error;
 921
 922         file->private_data = fid;
 923 #ifdef CONFIG_9P_FSCACHE
 924         if (v9ses->cache)
 925                 v9fs_cache_inode_set_cookie(dentry->d_inode, file);
 926 #endif
 927
 928         *opened |= FILE_CREATED;
 929 out:
 930         dput(res);
 931         return err;
 932
 933 error:
 934         if (fid)
 935                 p9_client_clunk(fid);
 936         goto out;
 937 }
 938
 939 /**
 940  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 941  * @i:  inode that is being unlinked
 942  * @d: dentry that is being unlinked
 943  *
 944  */
 945
 946 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 947 {
 948         return v9fs_remove(i, d, 0);
 949 }
 950
 951 /**
 952  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 953  * @i:  inode that is being unlinked
 954  * @d: dentry that is being unlinked
 955  *
 956  */
 957
 958 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 959 {
 960         return v9fs_remove(i, d, AT_REMOVEDIR);
 961 }
 962
 963 /**
 964  * v9fs_vfs_rename - VFS hook to rename an inode
 965  * @old_dir:  old dir inode
 966  * @old_dentry: old dentry
 967  * @new_dir: new dir inode
 968  * @new_dentry: new dentry
 969  *
 970  */
 971
 972 int
 973 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 974                 struct inode *new_dir, struct dentry *new_dentry)
 975 {
 976         int retval;
 977         struct inode *old_inode;
 978         struct inode *new_inode;
 979         struct v9fs_session_info *v9ses;
 980         struct p9_fid *oldfid;
 981         struct p9_fid *olddirfid;
 982         struct p9_fid *newdirfid;
 983         struct p9_wstat wstat;
 984
 985         p9_debug(P9_DEBUG_VFS, "\n");
 986         retval = 0;
 987         old_inode = old_dentry->d_inode;
 988         new_inode = new_dentry->d_inode;
 989         v9ses = v9fs_inode2v9ses(old_inode);
 990         oldfid = v9fs_fid_lookup(old_dentry);
 991         if (IS_ERR(oldfid))
 992                 return PTR_ERR(oldfid);
 993
 994         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 995         if (IS_ERR(olddirfid)) {
 996                 retval = PTR_ERR(olddirfid);
 997                 goto done;
 998         }
 999
1000         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
1001         if (IS_ERR(newdirfid)) {
1002                 retval = PTR_ERR(newdirfid);
1003                 goto clunk_olddir;
1004         }
1005
1006         down_write(&v9ses->rename_sem);
1007         if (v9fs_proto_dotl(v9ses)) {
1008                 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
1009                                             newdirfid, new_dentry->d_name.name);
1010                 if (retval == -EOPNOTSUPP)
1011                         retval = p9_client_rename(oldfid, newdirfid,
1012                                                   new_dentry->d_name.name);
1013                 if (retval != -EOPNOTSUPP)
1014                         goto clunk_newdir;
1015         }
1016         if (old_dentry->d_parent != new_dentry->d_parent) {
1017                 /*
1018                  * 9P .u can only handle file rename in the same directory
1019                  */
1020
1021                 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
1022                 retval = -EXDEV;
1023                 goto clunk_newdir;
1024         }
1025         v9fs_blank_wstat(&wstat);
1026         wstat.muid = v9ses->uname;
1027         wstat.name = (char *) new_dentry->d_name.name;
1028         retval = p9_client_wstat(oldfid, &wstat);
1029
1030 clunk_newdir:
1031         if (!retval) {
1032                 if (new_inode) {
1033                         if (S_ISDIR(new_inode->i_mode))
1034                                 clear_nlink(new_inode);
1035                         else
1036                                 drop_nlink(new_inode);
1037                 }
1038                 if (S_ISDIR(old_inode->i_mode)) {
1039                         if (!new_inode)
1040                                 inc_nlink(new_dir);
1041                         drop_nlink(old_dir);
1042                 }
1043                 v9fs_invalidate_inode_attr(old_inode);
1044                 v9fs_invalidate_inode_attr(old_dir);
1045                 v9fs_invalidate_inode_attr(new_dir);
1046
1047                 /* successful rename */
1048                 d_move(old_dentry, new_dentry);
1049         }
1050         up_write(&v9ses->rename_sem);
1051         p9_client_clunk(newdirfid);
1052
1053 clunk_olddir:
1054         p9_client_clunk(olddirfid);
1055
1056 done:
1057         return retval;
1058 }
1059
1060 /**
1061  * v9fs_vfs_getattr - retrieve file metadata
1062  * @mnt: mount information
1063  * @dentry: file to get attributes on
1064  * @stat: metadata structure to populate
1065  *
1066  */
1067
1068 static int
1069 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1070                  struct kstat *stat)
1071 {
1072         int err;
1073         struct v9fs_session_info *v9ses;
1074         struct p9_fid *fid;
1075         struct p9_wstat *st;
1076
1077         p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1078         err = -EPERM;
1079         v9ses = v9fs_dentry2v9ses(dentry);
1080         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1081                 generic_fillattr(dentry->d_inode, stat);
1082                 return 0;
1083         }
1084         fid = v9fs_fid_lookup(dentry);
1085         if (IS_ERR(fid))
1086                 return PTR_ERR(fid);
1087
1088         st = p9_client_stat(fid);
1089         if (IS_ERR(st))
1090                 return PTR_ERR(st);
1091
1092         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1093         generic_fillattr(dentry->d_inode, stat);
1094
1095         p9stat_free(st);
1096         kfree(st);
1097         return 0;
1098 }
1099
1100 /**
1101  * v9fs_vfs_setattr - set file metadata
1102  * @dentry: file whose metadata to set
1103  * @iattr: metadata assignment structure
1104  *
1105  */
1106
1107 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1108 {
1109         int retval;
1110         struct v9fs_session_info *v9ses;
1111         struct p9_fid *fid;
1112         struct p9_wstat wstat;
1113
1114         p9_debug(P9_DEBUG_VFS, "\n");
1115         retval = inode_change_ok(dentry->d_inode, iattr);
1116         if (retval)
1117                 return retval;
1118
1119         retval = -EPERM;
1120         v9ses = v9fs_dentry2v9ses(dentry);
1121         fid = v9fs_fid_lookup(dentry);
1122         if(IS_ERR(fid))
1123                 return PTR_ERR(fid);
1124
1125         v9fs_blank_wstat(&wstat);
1126         if (iattr->ia_valid & ATTR_MODE)
1127                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1128
1129         if (iattr->ia_valid & ATTR_MTIME)
1130                 wstat.mtime = iattr->ia_mtime.tv_sec;
1131
1132         if (iattr->ia_valid & ATTR_ATIME)
1133                 wstat.atime = iattr->ia_atime.tv_sec;
1134
1135         if (iattr->ia_valid & ATTR_SIZE)
1136                 wstat.length = iattr->ia_size;
1137
1138         if (v9fs_proto_dotu(v9ses)) {
1139                 if (iattr->ia_valid & ATTR_UID)
1140                         wstat.n_uid = iattr->ia_uid;
1141
1142                 if (iattr->ia_valid & ATTR_GID)
1143                         wstat.n_gid = iattr->ia_gid;
1144         }
1145
1146         /* Write all dirty data */
1147         if (S_ISREG(dentry->d_inode->i_mode))
1148                 filemap_write_and_wait(dentry->d_inode->i_mapping);
1149
1150         retval = p9_client_wstat(fid, &wstat);
1151         if (retval < 0)
1152                 return retval;
1153
1154         if ((iattr->ia_valid & ATTR_SIZE) &&
1155             iattr->ia_size != i_size_read(dentry->d_inode))
1156                 truncate_setsize(dentry->d_inode, iattr->ia_size);
1157
1158         v9fs_invalidate_inode_attr(dentry->d_inode);
1159
1160         setattr_copy(dentry->d_inode, iattr);
1161         mark_inode_dirty(dentry->d_inode);
1162         return 0;
1163 }
1164
1165 /**
1166  * v9fs_stat2inode - populate an inode structure with mistat info
1167  * @stat: Plan 9 metadata (mistat) structure
1168  * @inode: inode to populate
1169  * @sb: superblock of filesystem
1170  *
1171  */
1172
1173 void
1174 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1175         struct super_block *sb)
1176 {
1177         umode_t mode;
1178         char ext[32];
1179         char tag_name[14];
1180         unsigned int i_nlink;
1181         struct v9fs_session_info *v9ses = sb->s_fs_info;
1182         struct v9fs_inode *v9inode = V9FS_I(inode);
1183
1184         set_nlink(inode, 1);
1185
1186         inode->i_atime.tv_sec = stat->atime;
1187         inode->i_mtime.tv_sec = stat->mtime;
1188         inode->i_ctime.tv_sec = stat->mtime;
1189
1190         inode->i_uid = v9ses->dfltuid;
1191         inode->i_gid = v9ses->dfltgid;
1192
1193         if (v9fs_proto_dotu(v9ses)) {
1194                 inode->i_uid = stat->n_uid;
1195                 inode->i_gid = stat->n_gid;
1196         }
1197         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1198                 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1199                         /*
1200                          * Hadlink support got added later to
1201                          * to the .u extension. So there can be
1202                          * server out there that doesn't support
1203                          * this even with .u extension. So check
1204                          * for non NULL stat->extension
1205                          */
1206                         strncpy(ext, stat->extension, sizeof(ext));
1207                         /* HARDLINKCOUNT %u */
1208                         sscanf(ext, "%13s %u", tag_name, &i_nlink);
1209                         if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1210                                 set_nlink(inode, i_nlink);
1211                 }
1212         }
1213         mode = p9mode2perm(v9ses, stat);
1214         mode |= inode->i_mode & ~S_IALLUGO;
1215         inode->i_mode = mode;
1216         i_size_write(inode, stat->length);
1217
1218         /* not real number of blocks, but 512 byte ones ... */
1219         inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1220         v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1221 }
1222
1223 /**
1224  * v9fs_qid2ino - convert qid into inode number
1225  * @qid: qid to hash
1226  *
1227  * BUG: potential for inode number collisions?
1228  */
1229
1230 ino_t v9fs_qid2ino(struct p9_qid *qid)
1231 {
1232         u64 path = qid->path + 2;
1233         ino_t i = 0;
1234
1235         if (sizeof(ino_t) == sizeof(path))
1236                 memcpy(&i, &path, sizeof(ino_t));
1237         else
1238                 i = (ino_t) (path ^ (path >> 32));
1239
1240         return i;
1241 }
1242
1243 /**
1244  * v9fs_readlink - read a symlink's location (internal version)
1245  * @dentry: dentry for symlink
1246  * @buffer: buffer to load symlink location into
1247  * @buflen: length of buffer
1248  *
1249  */
1250
1251 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1252 {
1253         int retval;
1254
1255         struct v9fs_session_info *v9ses;
1256         struct p9_fid *fid;
1257         struct p9_wstat *st;
1258
1259         p9_debug(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1260         retval = -EPERM;
1261         v9ses = v9fs_dentry2v9ses(dentry);
1262         fid = v9fs_fid_lookup(dentry);
1263         if (IS_ERR(fid))
1264                 return PTR_ERR(fid);
1265
1266         if (!v9fs_proto_dotu(v9ses))
1267                 return -EBADF;
1268
1269         st = p9_client_stat(fid);
1270         if (IS_ERR(st))
1271                 return PTR_ERR(st);
1272
1273         if (!(st->mode & P9_DMSYMLINK)) {
1274                 retval = -EINVAL;
1275                 goto done;
1276         }
1277
1278         /* copy extension buffer into buffer */
1279         strncpy(buffer, st->extension, buflen);
1280
1281         p9_debug(P9_DEBUG_VFS, "%s -> %s (%s)\n",
1282                  dentry->d_name.name, st->extension, buffer);
1283
1284         retval = strnlen(buffer, buflen);
1285 done:
1286         p9stat_free(st);
1287         kfree(st);
1288         return retval;
1289 }
1290
1291 /**
1292  * v9fs_vfs_follow_link - follow a symlink path
1293  * @dentry: dentry for symlink
1294  * @nd: nameidata
1295  *
1296  */
1297
1298 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1299 {
1300         int len = 0;
1301         char *link = __getname();
1302
1303         p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);
1304
1305         if (!link)
1306                 link = ERR_PTR(-ENOMEM);
1307         else {
1308                 len = v9fs_readlink(dentry, link, PATH_MAX);
1309
1310                 if (len < 0) {
1311                         __putname(link);
1312                         link = ERR_PTR(len);
1313                 } else
1314                         link[min(len, PATH_MAX-1)] = 0;
1315         }
1316         nd_set_link(nd, link);
1317
1318         return NULL;
1319 }
1320
1321 /**
1322  * v9fs_vfs_put_link - release a symlink path
1323  * @dentry: dentry for symlink
1324  * @nd: nameidata
1325  * @p: unused
1326  *
1327  */
1328
1329 void
1330 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1331 {
1332         char *s = nd_get_link(nd);
1333
1334         p9_debug(P9_DEBUG_VFS, " %s %s\n",
1335                  dentry->d_name.name, IS_ERR(s) ? "<error>" : s);
1336         if (!IS_ERR(s))
1337                 __putname(s);
1338 }
1339
1340 /**
1341  * v9fs_vfs_mkspecial - create a special file
1342  * @dir: inode to create special file in
1343  * @dentry: dentry to create
1344  * @mode: mode to create special file
1345  * @extension: 9p2000.u format extension string representing special file
1346  *
1347  */
1348
1349 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1350         u32 perm, const char *extension)
1351 {
1352         struct p9_fid *fid;
1353         struct v9fs_session_info *v9ses;
1354
1355         v9ses = v9fs_inode2v9ses(dir);
1356         if (!v9fs_proto_dotu(v9ses)) {
1357                 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1358                 return -EPERM;
1359         }
1360
1361         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1362                                                                 P9_OREAD);
1363         if (IS_ERR(fid))
1364                 return PTR_ERR(fid);
1365
1366         v9fs_invalidate_inode_attr(dir);
1367         p9_client_clunk(fid);
1368         return 0;
1369 }
1370
1371 /**
1372  * v9fs_vfs_symlink - helper function to create symlinks
1373  * @dir: directory inode containing symlink
1374  * @dentry: dentry for symlink
1375  * @symname: symlink data
1376  *
1377  * See Also: 9P2000.u RFC for more information
1378  *
1379  */
1380
1381 static int
1382 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1383 {
1384         p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1385                  dir->i_ino, dentry->d_name.name, symname);
1386
1387         return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1388 }
1389
1390 /**
1391  * v9fs_vfs_link - create a hardlink
1392  * @old_dentry: dentry for file to link to
1393  * @dir: inode destination for new link
1394  * @dentry: dentry for link
1395  *
1396  */
1397
1398 static int
1399 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1400               struct dentry *dentry)
1401 {
1402         int retval;
1403         char *name;
1404         struct p9_fid *oldfid;
1405
1406         p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1407                  dir->i_ino, dentry->d_name.name, old_dentry->d_name.name);
1408
1409         oldfid = v9fs_fid_clone(old_dentry);
1410         if (IS_ERR(oldfid))
1411                 return PTR_ERR(oldfid);
1412
1413         name = __getname();
1414         if (unlikely(!name)) {
1415                 retval = -ENOMEM;
1416                 goto clunk_fid;
1417         }
1418
1419         sprintf(name, "%d\n", oldfid->fid);
1420         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1421         __putname(name);
1422         if (!retval) {
1423                 v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1424                 v9fs_invalidate_inode_attr(dir);
1425         }
1426 clunk_fid:
1427         p9_client_clunk(oldfid);
1428         return retval;
1429 }
1430
1431 /**
1432  * v9fs_vfs_mknod - create a special file
1433  * @dir: inode destination for new link
1434  * @dentry: dentry for file
1435  * @mode: mode for creation
1436  * @rdev: device associated with special file
1437  *
1438  */
1439
1440 static int
1441 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1442 {
1443         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1444         int retval;
1445         char *name;
1446         u32 perm;
1447
1448         p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %hx MAJOR: %u MINOR: %u\n",
1449                  dir->i_ino, dentry->d_name.name, mode,
1450                  MAJOR(rdev), MINOR(rdev));
1451
1452         if (!new_valid_dev(rdev))
1453                 return -EINVAL;
1454
1455         name = __getname();
1456         if (!name)
1457                 return -ENOMEM;
1458         /* build extension */
1459         if (S_ISBLK(mode))
1460                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1461         else if (S_ISCHR(mode))
1462                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1463         else if (S_ISFIFO(mode))
1464                 *name = 0;
1465         else if (S_ISSOCK(mode))
1466                 *name = 0;
1467         else {
1468                 __putname(name);
1469                 return -EINVAL;
1470         }
1471
1472         perm = unixmode2p9mode(v9ses, mode);
1473         retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1474         __putname(name);
1475
1476         return retval;
1477 }
1478
1479 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1480 {
1481         int umode;
1482         dev_t rdev;
1483         loff_t i_size;
1484         struct p9_wstat *st;
1485         struct v9fs_session_info *v9ses;
1486
1487         v9ses = v9fs_inode2v9ses(inode);
1488         st = p9_client_stat(fid);
1489         if (IS_ERR(st))
1490                 return PTR_ERR(st);
1491         /*
1492          * Don't update inode if the file type is different
1493          */
1494         umode = p9mode2unixmode(v9ses, st, &rdev);
1495         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1496                 goto out;
1497
1498         spin_lock(&inode->i_lock);
1499         /*
1500          * We don't want to refresh inode->i_size,
1501          * because we may have cached data
1502          */
1503         i_size = inode->i_size;
1504         v9fs_stat2inode(st, inode, inode->i_sb);
1505         if (v9ses->cache)
1506                 inode->i_size = i_size;
1507         spin_unlock(&inode->i_lock);
1508 out:
1509         p9stat_free(st);
1510         kfree(st);
1511         return 0;
1512 }
1513
1514 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1515         .create = v9fs_vfs_create,
1516         .lookup = v9fs_vfs_lookup,
1517         .atomic_open = v9fs_vfs_atomic_open,
1518         .symlink = v9fs_vfs_symlink,
1519         .link = v9fs_vfs_link,
1520         .unlink = v9fs_vfs_unlink,
1521         .mkdir = v9fs_vfs_mkdir,
1522         .rmdir = v9fs_vfs_rmdir,
1523         .mknod = v9fs_vfs_mknod,
1524         .rename = v9fs_vfs_rename,
1525         .getattr = v9fs_vfs_getattr,
1526         .setattr = v9fs_vfs_setattr,
1527 };
1528
1529 static const struct inode_operations v9fs_dir_inode_operations = {
1530         .create = v9fs_vfs_create,
1531         .lookup = v9fs_vfs_lookup,
1532         .atomic_open = v9fs_vfs_atomic_open,
1533         .unlink = v9fs_vfs_unlink,
1534         .mkdir = v9fs_vfs_mkdir,
1535         .rmdir = v9fs_vfs_rmdir,
1536         .mknod = v9fs_vfs_mknod,
1537         .rename = v9fs_vfs_rename,
1538         .getattr = v9fs_vfs_getattr,
1539         .setattr = v9fs_vfs_setattr,
1540 };
1541
1542 static const struct inode_operations v9fs_file_inode_operations = {
1543         .getattr = v9fs_vfs_getattr,
1544         .setattr = v9fs_vfs_setattr,
1545 };
1546
1547 static const struct inode_operations v9fs_symlink_inode_operations = {
1548         .readlink = generic_readlink,
1549         .follow_link = v9fs_vfs_follow_link,
1550         .put_link = v9fs_vfs_put_link,
1551         .getattr = v9fs_vfs_getattr,
1552         .setattr = v9fs_vfs_setattr,
1553 };
1554