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 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/fs.h>
  29 #include <linux/file.h>
  30 #include <linux/pagemap.h>
  31 #include <linux/stat.h>
  32 #include <linux/string.h>
  33 #include <linux/inet.h>
  34 #include <linux/namei.h>
  35 #include <linux/idr.h>
  36 #include <linux/sched.h>
  37 #include <linux/slab.h>
  38 #include <linux/xattr.h>
  39 #include <linux/posix_acl.h>
  40 #include <net/9p/9p.h>
  41 #include <net/9p/client.h>
  42
  43 #include "v9fs.h"
  44 #include "v9fs_vfs.h"
  45 #include "fid.h"
  46 #include "cache.h"
  47 #include "xattr.h"
  48 #include "acl.h"
  49
  50 static const struct inode_operations v9fs_dir_inode_operations;
  51 static const struct inode_operations v9fs_dir_inode_operations_dotu;
  52 static const struct inode_operations v9fs_file_inode_operations;
  53 static const struct inode_operations v9fs_symlink_inode_operations;
  54
  55 /**
  56  * unixmode2p9mode - convert unix mode bits to plan 9
  57  * @v9ses: v9fs session information
  58  * @mode: mode to convert
  59  *
  60  */
  61
  62 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
  63 {
  64         int res;
  65         res = mode & 0777;
  66         if (S_ISDIR(mode))
  67                 res |= P9_DMDIR;
  68         if (v9fs_proto_dotu(v9ses)) {
  69                 if (S_ISLNK(mode))
  70                         res |= P9_DMSYMLINK;
  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                 if ((mode & P9_DMLINK))
  89                         res |= P9_DMLINK;
  90         }
  91
  92         return res;
  93 }
  94
  95 /**
  96  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  97  * @v9ses: v9fs session information
  98  * @stat: p9_wstat from which mode need to be derived
  99  * @rdev: major number, minor number in case of device files.
 100  *
 101  */
 102 static int p9mode2unixmode(struct v9fs_session_info *v9ses,
 103                            struct p9_wstat *stat, dev_t *rdev)
 104 {
 105         int res;
 106         int mode = stat->mode;
 107
 108         res = mode & S_IALLUGO;
 109         *rdev = 0;
 110
 111         if ((mode & P9_DMDIR) == P9_DMDIR)
 112                 res |= S_IFDIR;
 113         else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 114                 res |= S_IFLNK;
 115         else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 116                  && (v9ses->nodev == 0))
 117                 res |= S_IFSOCK;
 118         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 119                  && (v9ses->nodev == 0))
 120                 res |= S_IFIFO;
 121         else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 122                  && (v9ses->nodev == 0)) {
 123                 char type = 0, ext[32];
 124                 int major = -1, minor = -1;
 125
 126                 strncpy(ext, stat->extension, sizeof(ext));
 127                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 128                 switch (type) {
 129                 case 'c':
 130                         res |= S_IFCHR;
 131                         break;
 132                 case 'b':
 133                         res |= S_IFBLK;
 134                         break;
 135                 default:
 136                         P9_DPRINTK(P9_DEBUG_ERROR,
 137                                 "Unknown special type %c %s\n", type,
 138                                 stat->extension);
 139                 };
 140                 *rdev = MKDEV(major, minor);
 141         } else
 142                 res |= S_IFREG;
 143
 144         if (v9fs_proto_dotu(v9ses)) {
 145                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
 146                         res |= S_ISUID;
 147
 148                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
 149                         res |= S_ISGID;
 150
 151                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 152                         res |= S_ISVTX;
 153         }
 154         return res;
 155 }
 156
 157 /**
 158  * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 159  * @uflags: flags to convert
 160  * @extended: if .u extensions are active
 161  */
 162
 163 int v9fs_uflags2omode(int uflags, int extended)
 164 {
 165         int ret;
 166
 167         ret = 0;
 168         switch (uflags&3) {
 169         default:
 170         case O_RDONLY:
 171                 ret = P9_OREAD;
 172                 break;
 173
 174         case O_WRONLY:
 175                 ret = P9_OWRITE;
 176                 break;
 177
 178         case O_RDWR:
 179                 ret = P9_ORDWR;
 180                 break;
 181         }
 182
 183         if (uflags & O_TRUNC)
 184                 ret |= P9_OTRUNC;
 185
 186         if (extended) {
 187                 if (uflags & O_EXCL)
 188                         ret |= P9_OEXCL;
 189
 190                 if (uflags & O_APPEND)
 191                         ret |= P9_OAPPEND;
 192         }
 193
 194         return ret;
 195 }
 196
 197 /**
 198  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 199  * @wstat: structure to initialize
 200  *
 201  */
 202
 203 void
 204 v9fs_blank_wstat(struct p9_wstat *wstat)
 205 {
 206         wstat->type = ~0;
 207         wstat->dev = ~0;
 208         wstat->qid.type = ~0;
 209         wstat->qid.version = ~0;
 210         *((long long *)&wstat->qid.path) = ~0;
 211         wstat->mode = ~0;
 212         wstat->atime = ~0;
 213         wstat->mtime = ~0;
 214         wstat->length = ~0;
 215         wstat->name = NULL;
 216         wstat->uid = NULL;
 217         wstat->gid = NULL;
 218         wstat->muid = NULL;
 219         wstat->n_uid = ~0;
 220         wstat->n_gid = ~0;
 221         wstat->n_muid = ~0;
 222         wstat->extension = NULL;
 223 }
 224
 225 /**
 226  * v9fs_alloc_inode - helper function to allocate an inode
 227  *
 228  */
 229 struct inode *v9fs_alloc_inode(struct super_block *sb)
 230 {
 231         struct v9fs_inode *v9inode;
 232         v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 233                                                         GFP_KERNEL);
 234         if (!v9inode)
 235                 return NULL;
 236 #ifdef CONFIG_9P_FSCACHE
 237         v9inode->fscache = NULL;
 238         spin_lock_init(&v9inode->fscache_lock);
 239 #endif
 240         v9inode->writeback_fid = NULL;
 241         v9inode->cache_validity = 0;
 242         mutex_init(&v9inode->v_mutex);
 243         return &v9inode->vfs_inode;
 244 }
 245
 246 /**
 247  * v9fs_destroy_inode - destroy an inode
 248  *
 249  */
 250
 251 static void v9fs_i_callback(struct rcu_head *head)
 252 {
 253         struct inode *inode = container_of(head, struct inode, i_rcu);
 254         INIT_LIST_HEAD(&inode->i_dentry);
 255         kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 256 }
 257
 258 void v9fs_destroy_inode(struct inode *inode)
 259 {
 260         call_rcu(&inode->i_rcu, v9fs_i_callback);
 261 }
 262
 263 int v9fs_init_inode(struct v9fs_session_info *v9ses,
 264                     struct inode *inode, int mode, dev_t rdev)
 265 {
 266         int err = 0;
 267
 268         inode_init_owner(inode, NULL, mode);
 269         inode->i_blocks = 0;
 270         inode->i_rdev = rdev;
 271         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 272         inode->i_mapping->a_ops = &v9fs_addr_operations;
 273
 274         switch (mode & S_IFMT) {
 275         case S_IFIFO:
 276         case S_IFBLK:
 277         case S_IFCHR:
 278         case S_IFSOCK:
 279                 if (v9fs_proto_dotl(v9ses)) {
 280                         inode->i_op = &v9fs_file_inode_operations_dotl;
 281                         inode->i_fop = &v9fs_file_operations_dotl;
 282                 } else if (v9fs_proto_dotu(v9ses)) {
 283                         inode->i_op = &v9fs_file_inode_operations;
 284                         inode->i_fop = &v9fs_file_operations;
 285                 } else {
 286                         P9_DPRINTK(P9_DEBUG_ERROR,
 287                                    "special files without extended mode\n");
 288                         err = -EINVAL;
 289                         goto error;
 290                 }
 291                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 292                 break;
 293         case S_IFREG:
 294                 if (v9fs_proto_dotl(v9ses)) {
 295                         inode->i_op = &v9fs_file_inode_operations_dotl;
 296                         if (v9ses->cache)
 297                                 inode->i_fop =
 298                                         &v9fs_cached_file_operations_dotl;
 299                         else
 300                                 inode->i_fop = &v9fs_file_operations_dotl;
 301                 } else {
 302                         inode->i_op = &v9fs_file_inode_operations;
 303                         if (v9ses->cache)
 304                                 inode->i_fop = &v9fs_cached_file_operations;
 305                         else
 306                                 inode->i_fop = &v9fs_file_operations;
 307                 }
 308
 309                 break;
 310         case S_IFLNK:
 311                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 312                         P9_DPRINTK(P9_DEBUG_ERROR, "extended modes used with "
 313                                                 "legacy protocol.\n");
 314                         err = -EINVAL;
 315                         goto error;
 316                 }
 317
 318                 if (v9fs_proto_dotl(v9ses))
 319                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
 320                 else
 321                         inode->i_op = &v9fs_symlink_inode_operations;
 322
 323                 break;
 324         case S_IFDIR:
 325                 inc_nlink(inode);
 326                 if (v9fs_proto_dotl(v9ses))
 327                         inode->i_op = &v9fs_dir_inode_operations_dotl;
 328                 else if (v9fs_proto_dotu(v9ses))
 329                         inode->i_op = &v9fs_dir_inode_operations_dotu;
 330                 else
 331                         inode->i_op = &v9fs_dir_inode_operations;
 332
 333                 if (v9fs_proto_dotl(v9ses))
 334                         inode->i_fop = &v9fs_dir_operations_dotl;
 335                 else
 336                         inode->i_fop = &v9fs_dir_operations;
 337
 338                 break;
 339         default:
 340                 P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
 341                            mode, mode & S_IFMT);
 342                 err = -EINVAL;
 343                 goto error;
 344         }
 345 error:
 346         return err;
 347
 348 }
 349
 350 /**
 351  * v9fs_get_inode - helper function to setup an inode
 352  * @sb: superblock
 353  * @mode: mode to setup inode with
 354  *
 355  */
 356
 357 struct inode *v9fs_get_inode(struct super_block *sb, int mode, dev_t rdev)
 358 {
 359         int err;
 360         struct inode *inode;
 361         struct v9fs_session_info *v9ses = sb->s_fs_info;
 362
 363         P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 364
 365         inode = new_inode(sb);
 366         if (!inode) {
 367                 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
 368                 return ERR_PTR(-ENOMEM);
 369         }
 370         err = v9fs_init_inode(v9ses, inode, mode, rdev);
 371         if (err) {
 372                 iput(inode);
 373                 return ERR_PTR(err);
 374         }
 375         return inode;
 376 }
 377
 378 /*
 379 static struct v9fs_fid*
 380 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 381 {
 382         int err;
 383         int nfid;
 384         struct v9fs_fid *ret;
 385         struct v9fs_fcall *fcall;
 386
 387         nfid = v9fs_get_idpool(&v9ses->fidpool);
 388         if (nfid < 0) {
 389                 eprintk(KERN_WARNING, "no free fids available\n");
 390                 return ERR_PTR(-ENOSPC);
 391         }
 392
 393         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 394                 &fcall);
 395
 396         if (err < 0) {
 397                 if (fcall && fcall->id == RWALK)
 398                         goto clunk_fid;
 399
 400                 PRINT_FCALL_ERROR("walk error", fcall);
 401                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 402                 goto error;
 403         }
 404
 405         kfree(fcall);
 406         fcall = NULL;
 407         ret = v9fs_fid_create(v9ses, nfid);
 408         if (!ret) {
 409                 err = -ENOMEM;
 410                 goto clunk_fid;
 411         }
 412
 413         err = v9fs_fid_insert(ret, dentry);
 414         if (err < 0) {
 415                 v9fs_fid_destroy(ret);
 416                 goto clunk_fid;
 417         }
 418
 419         return ret;
 420
 421 clunk_fid:
 422         v9fs_t_clunk(v9ses, nfid);
 423
 424 error:
 425         kfree(fcall);
 426         return ERR_PTR(err);
 427 }
 428 */
 429
 430
 431 /**
 432  * v9fs_clear_inode - release an inode
 433  * @inode: inode to release
 434  *
 435  */
 436 void v9fs_evict_inode(struct inode *inode)
 437 {
 438         struct v9fs_inode *v9inode = V9FS_I(inode);
 439
 440         truncate_inode_pages(inode->i_mapping, 0);
 441         end_writeback(inode);
 442         filemap_fdatawrite(inode->i_mapping);
 443
 444 #ifdef CONFIG_9P_FSCACHE
 445         v9fs_cache_inode_put_cookie(inode);
 446 #endif
 447         /* clunk the fid stashed in writeback_fid */
 448         if (v9inode->writeback_fid) {
 449                 p9_client_clunk(v9inode->writeback_fid);
 450                 v9inode->writeback_fid = NULL;
 451         }
 452 }
 453
 454 static int v9fs_test_inode(struct inode *inode, void *data)
 455 {
 456         int umode;
 457         dev_t rdev;
 458         struct v9fs_inode *v9inode = V9FS_I(inode);
 459         struct p9_wstat *st = (struct p9_wstat *)data;
 460         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 461
 462         umode = p9mode2unixmode(v9ses, st, &rdev);
 463         /* don't match inode of different type */
 464         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 465                 return 0;
 466
 467         /* compare qid details */
 468         if (memcmp(&v9inode->qid.version,
 469                    &st->qid.version, sizeof(v9inode->qid.version)))
 470                 return 0;
 471
 472         if (v9inode->qid.type != st->qid.type)
 473                 return 0;
 474         return 1;
 475 }
 476
 477 static int v9fs_test_new_inode(struct inode *inode, void *data)
 478 {
 479         return 0;
 480 }
 481
 482 static int v9fs_set_inode(struct inode *inode,  void *data)
 483 {
 484         struct v9fs_inode *v9inode = V9FS_I(inode);
 485         struct p9_wstat *st = (struct p9_wstat *)data;
 486
 487         memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 488         return 0;
 489 }
 490
 491 static struct inode *v9fs_qid_iget(struct super_block *sb,
 492                                    struct p9_qid *qid,
 493                                    struct p9_wstat *st,
 494                                    int new)
 495 {
 496         dev_t rdev;
 497         int retval, umode;
 498         unsigned long i_ino;
 499         struct inode *inode;
 500         struct v9fs_session_info *v9ses = sb->s_fs_info;
 501         int (*test)(struct inode *, void *);
 502
 503         if (new)
 504                 test = v9fs_test_new_inode;
 505         else
 506                 test = v9fs_test_inode;
 507
 508         i_ino = v9fs_qid2ino(qid);
 509         inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 510         if (!inode)
 511                 return ERR_PTR(-ENOMEM);
 512         if (!(inode->i_state & I_NEW))
 513                 return inode;
 514         /*
 515          * initialize the inode with the stat info
 516          * FIXME!! we may need support for stale inodes
 517          * later.
 518          */
 519         inode->i_ino = i_ino;
 520         umode = p9mode2unixmode(v9ses, st, &rdev);
 521         retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 522         if (retval)
 523                 goto error;
 524
 525         v9fs_stat2inode(st, inode, sb);
 526 #ifdef CONFIG_9P_FSCACHE
 527         v9fs_cache_inode_get_cookie(inode);
 528 #endif
 529         unlock_new_inode(inode);
 530         return inode;
 531 error:
 532         unlock_new_inode(inode);
 533         iput(inode);
 534         return ERR_PTR(retval);
 535
 536 }
 537
 538 struct inode *
 539 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 540                     struct super_block *sb, int new)
 541 {
 542         struct p9_wstat *st;
 543         struct inode *inode = NULL;
 544
 545         st = p9_client_stat(fid);
 546         if (IS_ERR(st))
 547                 return ERR_CAST(st);
 548
 549         inode = v9fs_qid_iget(sb, &st->qid, st, new);
 550         p9stat_free(st);
 551         kfree(st);
 552         return inode;
 553 }
 554
 555 /**
 556  * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 557  * plan 9 AT flag.
 558  * @flags: flags to convert
 559  */
 560 static int v9fs_at_to_dotl_flags(int flags)
 561 {
 562         int rflags = 0;
 563         if (flags & AT_REMOVEDIR)
 564                 rflags |= P9_DOTL_AT_REMOVEDIR;
 565         return rflags;
 566 }
 567
 568 /**
 569  * v9fs_remove - helper function to remove files and directories
 570  * @dir: directory inode that is being deleted
 571  * @dentry:  dentry that is being deleted
 572  * @rmdir: removing a directory
 573  *
 574  */
 575
 576 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 577 {
 578         struct inode *inode;
 579         int retval = -EOPNOTSUPP;
 580         struct p9_fid *v9fid, *dfid;
 581         struct v9fs_session_info *v9ses;
 582
 583         P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 584                    dir, dentry, flags);
 585
 586         v9ses = v9fs_inode2v9ses(dir);
 587         inode = dentry->d_inode;
 588         dfid = v9fs_fid_lookup(dentry->d_parent);
 589         if (IS_ERR(dfid)) {
 590                 retval = PTR_ERR(dfid);
 591                 P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 592                 return retval;
 593         }
 594         if (v9fs_proto_dotl(v9ses))
 595                 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 596                                             v9fs_at_to_dotl_flags(flags));
 597         if (retval == -EOPNOTSUPP) {
 598                 /* Try the one based on path */
 599                 v9fid = v9fs_fid_clone(dentry);
 600                 if (IS_ERR(v9fid))
 601                         return PTR_ERR(v9fid);
 602                 retval = p9_client_remove(v9fid);
 603         }
 604         if (!retval) {
 605                 /*
 606                  * directories on unlink should have zero
 607                  * link count
 608                  */
 609                 if (flags & AT_REMOVEDIR) {
 610                         clear_nlink(inode);
 611                         drop_nlink(dir);
 612                 } else
 613                         drop_nlink(inode);
 614
 615                 v9fs_invalidate_inode_attr(inode);
 616                 v9fs_invalidate_inode_attr(dir);
 617         }
 618         return retval;
 619 }
 620
 621 /**
 622  * v9fs_create - Create a file
 623  * @v9ses: session information
 624  * @dir: directory that dentry is being created in
 625  * @dentry:  dentry that is being created
 626  * @extension: 9p2000.u extension string to support devices, etc.
 627  * @perm: create permissions
 628  * @mode: open mode
 629  *
 630  */
 631 static struct p9_fid *
 632 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 633                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 634 {
 635         int err;
 636         char *name;
 637         struct p9_fid *dfid, *ofid, *fid;
 638         struct inode *inode;
 639
 640         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 641
 642         err = 0;
 643         ofid = NULL;
 644         fid = NULL;
 645         name = (char *) dentry->d_name.name;
 646         dfid = v9fs_fid_lookup(dentry->d_parent);
 647         if (IS_ERR(dfid)) {
 648                 err = PTR_ERR(dfid);
 649                 P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 650                 return ERR_PTR(err);
 651         }
 652
 653         /* clone a fid to use for creation */
 654         ofid = p9_client_walk(dfid, 0, NULL, 1);
 655         if (IS_ERR(ofid)) {
 656                 err = PTR_ERR(ofid);
 657                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 658                 return ERR_PTR(err);
 659         }
 660
 661         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 662         if (err < 0) {
 663                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 664                 goto error;
 665         }
 666
 667         /* now walk from the parent so we can get unopened fid */
 668         fid = p9_client_walk(dfid, 1, &name, 1);
 669         if (IS_ERR(fid)) {
 670                 err = PTR_ERR(fid);
 671                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 672                 fid = NULL;
 673                 goto error;
 674         }
 675
 676         /* instantiate inode and assign the unopened fid to the dentry */
 677         inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 678         if (IS_ERR(inode)) {
 679                 err = PTR_ERR(inode);
 680                 P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
 681                 goto error;
 682         }
 683         err = v9fs_fid_add(dentry, fid);
 684         if (err < 0)
 685                 goto error;
 686         d_instantiate(dentry, inode);
 687         return ofid;
 688 error:
 689         if (ofid)
 690                 p9_client_clunk(ofid);
 691
 692         if (fid)
 693                 p9_client_clunk(fid);
 694
 695         return ERR_PTR(err);
 696 }
 697
 698 /**
 699  * v9fs_vfs_create - VFS hook to create files
 700  * @dir: directory inode that is being created
 701  * @dentry:  dentry that is being deleted
 702  * @mode: create permissions
 703  * @nd: path information
 704  *
 705  */
 706
 707 static int
 708 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 709                 struct nameidata *nd)
 710 {
 711         int err;
 712         u32 perm;
 713         int flags;
 714         struct file *filp;
 715         struct v9fs_inode *v9inode;
 716         struct v9fs_session_info *v9ses;
 717         struct p9_fid *fid, *inode_fid;
 718
 719         err = 0;
 720         fid = NULL;
 721         v9ses = v9fs_inode2v9ses(dir);
 722         perm = unixmode2p9mode(v9ses, mode);
 723         if (nd)
 724                 flags = nd->intent.open.flags;
 725         else
 726                 flags = O_RDWR;
 727
 728         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 729                                 v9fs_uflags2omode(flags,
 730                                                 v9fs_proto_dotu(v9ses)));
 731         if (IS_ERR(fid)) {
 732                 err = PTR_ERR(fid);
 733                 fid = NULL;
 734                 goto error;
 735         }
 736
 737         v9fs_invalidate_inode_attr(dir);
 738         /* if we are opening a file, assign the open fid to the file */
 739         if (nd) {
 740                 v9inode = V9FS_I(dentry->d_inode);
 741                 mutex_lock(&v9inode->v_mutex);
 742                 if (v9ses->cache && !v9inode->writeback_fid &&
 743                     ((flags & O_ACCMODE) != O_RDONLY)) {
 744                         /*
 745                          * clone a fid and add it to writeback_fid
 746                          * we do it during open time instead of
 747                          * page dirty time via write_begin/page_mkwrite
 748                          * because we want write after unlink usecase
 749                          * to work.
 750                          */
 751                         inode_fid = v9fs_writeback_fid(dentry);
 752                         if (IS_ERR(inode_fid)) {
 753                                 err = PTR_ERR(inode_fid);
 754                                 mutex_unlock(&v9inode->v_mutex);
 755                                 goto error;
 756                         }
 757                         v9inode->writeback_fid = (void *) inode_fid;
 758                 }
 759                 mutex_unlock(&v9inode->v_mutex);
 760                 filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
 761                 if (IS_ERR(filp)) {
 762                         err = PTR_ERR(filp);
 763                         goto error;
 764                 }
 765
 766                 filp->private_data = fid;
 767 #ifdef CONFIG_9P_FSCACHE
 768                 if (v9ses->cache)
 769                         v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
 770 #endif
 771         } else
 772                 p9_client_clunk(fid);
 773
 774         return 0;
 775
 776 error:
 777         if (fid)
 778                 p9_client_clunk(fid);
 779
 780         return err;
 781 }
 782
 783 /**
 784  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 785  * @dir:  inode that is being unlinked
 786  * @dentry: dentry that is being unlinked
 787  * @mode: mode for new directory
 788  *
 789  */
 790
 791 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 792 {
 793         int err;
 794         u32 perm;
 795         struct p9_fid *fid;
 796         struct v9fs_session_info *v9ses;
 797
 798         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 799         err = 0;
 800         v9ses = v9fs_inode2v9ses(dir);
 801         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 802         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 803         if (IS_ERR(fid)) {
 804                 err = PTR_ERR(fid);
 805                 fid = NULL;
 806         } else {
 807                 inc_nlink(dir);
 808                 v9fs_invalidate_inode_attr(dir);
 809         }
 810
 811         if (fid)
 812                 p9_client_clunk(fid);
 813
 814         return err;
 815 }
 816
 817 /**
 818  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 819  * @dir:  inode that is being walked from
 820  * @dentry: dentry that is being walked to?
 821  * @nameidata: path data
 822  *
 823  */
 824
 825 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 826                                       struct nameidata *nameidata)
 827 {
 828         struct dentry *res;
 829         struct super_block *sb;
 830         struct v9fs_session_info *v9ses;
 831         struct p9_fid *dfid, *fid;
 832         struct inode *inode;
 833         char *name;
 834         int result = 0;
 835
 836         P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 837                 dir, dentry->d_name.name, dentry, nameidata);
 838
 839         if (dentry->d_name.len > NAME_MAX)
 840                 return ERR_PTR(-ENAMETOOLONG);
 841
 842         sb = dir->i_sb;
 843         v9ses = v9fs_inode2v9ses(dir);
 844         /* We can walk d_parent because we hold the dir->i_mutex */
 845         dfid = v9fs_fid_lookup(dentry->d_parent);
 846         if (IS_ERR(dfid))
 847                 return ERR_CAST(dfid);
 848
 849         name = (char *) dentry->d_name.name;
 850         fid = p9_client_walk(dfid, 1, &name, 1);
 851         if (IS_ERR(fid)) {
 852                 result = PTR_ERR(fid);
 853                 if (result == -ENOENT) {
 854                         inode = NULL;
 855                         goto inst_out;
 856                 }
 857
 858                 return ERR_PTR(result);
 859         }
 860         /*
 861          * Make sure we don't use a wrong inode due to parallel
 862          * unlink. For cached mode create calls request for new
 863          * inode. But with cache disabled, lookup should do this.
 864          */
 865         if (v9ses->cache)
 866                 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 867         else
 868                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 869         if (IS_ERR(inode)) {
 870                 result = PTR_ERR(inode);
 871                 inode = NULL;
 872                 goto error;
 873         }
 874         result = v9fs_fid_add(dentry, fid);
 875         if (result < 0)
 876                 goto error_iput;
 877 inst_out:
 878         /*
 879          * If we had a rename on the server and a parallel lookup
 880          * for the new name, then make sure we instantiate with
 881          * the new name. ie look up for a/b, while on server somebody
 882          * moved b under k and client parallely did a lookup for
 883          * k/b.
 884          */
 885         res = d_materialise_unique(dentry, inode);
 886         if (!IS_ERR(res))
 887                 return res;
 888         result = PTR_ERR(res);
 889 error_iput:
 890         iput(inode);
 891 error:
 892         p9_client_clunk(fid);
 893
 894         return ERR_PTR(result);
 895 }
 896
 897 /**
 898  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 899  * @i:  inode that is being unlinked
 900  * @d: dentry that is being unlinked
 901  *
 902  */
 903
 904 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 905 {
 906         return v9fs_remove(i, d, 0);
 907 }
 908
 909 /**
 910  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 911  * @i:  inode that is being unlinked
 912  * @d: dentry that is being unlinked
 913  *
 914  */
 915
 916 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 917 {
 918         return v9fs_remove(i, d, AT_REMOVEDIR);
 919 }
 920
 921 /**
 922  * v9fs_vfs_rename - VFS hook to rename an inode
 923  * @old_dir:  old dir inode
 924  * @old_dentry: old dentry
 925  * @new_dir: new dir inode
 926  * @new_dentry: new dentry
 927  *
 928  */
 929
 930 int
 931 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 932                 struct inode *new_dir, struct dentry *new_dentry)
 933 {
 934         int retval;
 935         struct inode *old_inode;
 936         struct inode *new_inode;
 937         struct v9fs_session_info *v9ses;
 938         struct p9_fid *oldfid;
 939         struct p9_fid *olddirfid;
 940         struct p9_fid *newdirfid;
 941         struct p9_wstat wstat;
 942
 943         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 944         retval = 0;
 945         old_inode = old_dentry->d_inode;
 946         new_inode = new_dentry->d_inode;
 947         v9ses = v9fs_inode2v9ses(old_inode);
 948         oldfid = v9fs_fid_lookup(old_dentry);
 949         if (IS_ERR(oldfid))
 950                 return PTR_ERR(oldfid);
 951
 952         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 953         if (IS_ERR(olddirfid)) {
 954                 retval = PTR_ERR(olddirfid);
 955                 goto done;
 956         }
 957
 958         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 959         if (IS_ERR(newdirfid)) {
 960                 retval = PTR_ERR(newdirfid);
 961                 goto clunk_olddir;
 962         }
 963
 964         down_write(&v9ses->rename_sem);
 965         if (v9fs_proto_dotl(v9ses)) {
 966                 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 967                                             newdirfid, new_dentry->d_name.name);
 968                 if (retval == -EOPNOTSUPP)
 969                         retval = p9_client_rename(oldfid, newdirfid,
 970                                                   new_dentry->d_name.name);
 971                 if (retval != -EOPNOTSUPP)
 972                         goto clunk_newdir;
 973         }
 974         if (old_dentry->d_parent != new_dentry->d_parent) {
 975                 /*
 976                  * 9P .u can only handle file rename in the same directory
 977                  */
 978
 979                 P9_DPRINTK(P9_DEBUG_ERROR,
 980                                 "old dir and new dir are different\n");
 981                 retval = -EXDEV;
 982                 goto clunk_newdir;
 983         }
 984         v9fs_blank_wstat(&wstat);
 985         wstat.muid = v9ses->uname;
 986         wstat.name = (char *) new_dentry->d_name.name;
 987         retval = p9_client_wstat(oldfid, &wstat);
 988
 989 clunk_newdir:
 990         if (!retval) {
 991                 if (new_inode) {
 992                         if (S_ISDIR(new_inode->i_mode))
 993                                 clear_nlink(new_inode);
 994                         else
 995                                 drop_nlink(new_inode);
 996                 }
 997                 if (S_ISDIR(old_inode->i_mode)) {
 998                         if (!new_inode)
 999                                 inc_nlink(new_dir);
1000                         drop_nlink(old_dir);
1001                 }
1002                 v9fs_invalidate_inode_attr(old_inode);
1003                 v9fs_invalidate_inode_attr(old_dir);
1004                 v9fs_invalidate_inode_attr(new_dir);
1005
1006                 /* successful rename */
1007                 d_move(old_dentry, new_dentry);
1008         }
1009         up_write(&v9ses->rename_sem);
1010         p9_client_clunk(newdirfid);
1011
1012 clunk_olddir:
1013         p9_client_clunk(olddirfid);
1014
1015 done:
1016         return retval;
1017 }
1018
1019 /**
1020  * v9fs_vfs_getattr - retrieve file metadata
1021  * @mnt: mount information
1022  * @dentry: file to get attributes on
1023  * @stat: metadata structure to populate
1024  *
1025  */
1026
1027 static int
1028 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1029                  struct kstat *stat)
1030 {
1031         int err;
1032         struct v9fs_session_info *v9ses;
1033         struct p9_fid *fid;
1034         struct p9_wstat *st;
1035
1036         P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1037         err = -EPERM;
1038         v9ses = v9fs_dentry2v9ses(dentry);
1039         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1040                 generic_fillattr(dentry->d_inode, stat);
1041                 return 0;
1042         }
1043         fid = v9fs_fid_lookup(dentry);
1044         if (IS_ERR(fid))
1045                 return PTR_ERR(fid);
1046
1047         st = p9_client_stat(fid);
1048         if (IS_ERR(st))
1049                 return PTR_ERR(st);
1050
1051         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1052         generic_fillattr(dentry->d_inode, stat);
1053
1054         p9stat_free(st);
1055         kfree(st);
1056         return 0;
1057 }
1058
1059 /**
1060  * v9fs_vfs_setattr - set file metadata
1061  * @dentry: file whose metadata to set
1062  * @iattr: metadata assignment structure
1063  *
1064  */
1065
1066 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1067 {
1068         int retval;
1069         struct v9fs_session_info *v9ses;
1070         struct p9_fid *fid;
1071         struct p9_wstat wstat;
1072
1073         P9_DPRINTK(P9_DEBUG_VFS, "\n");
1074         retval = inode_change_ok(dentry->d_inode, iattr);
1075         if (retval)
1076                 return retval;
1077
1078         retval = -EPERM;
1079         v9ses = v9fs_dentry2v9ses(dentry);
1080         fid = v9fs_fid_lookup(dentry);
1081         if(IS_ERR(fid))
1082                 return PTR_ERR(fid);
1083
1084         v9fs_blank_wstat(&wstat);
1085         if (iattr->ia_valid & ATTR_MODE)
1086                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1087
1088         if (iattr->ia_valid & ATTR_MTIME)
1089                 wstat.mtime = iattr->ia_mtime.tv_sec;
1090
1091         if (iattr->ia_valid & ATTR_ATIME)
1092                 wstat.atime = iattr->ia_atime.tv_sec;
1093
1094         if (iattr->ia_valid & ATTR_SIZE)
1095                 wstat.length = iattr->ia_size;
1096
1097         if (v9fs_proto_dotu(v9ses)) {
1098                 if (iattr->ia_valid & ATTR_UID)
1099                         wstat.n_uid = iattr->ia_uid;
1100
1101                 if (iattr->ia_valid & ATTR_GID)
1102                         wstat.n_gid = iattr->ia_gid;
1103         }
1104
1105         /* Write all dirty data */
1106         if (S_ISREG(dentry->d_inode->i_mode))
1107                 filemap_write_and_wait(dentry->d_inode->i_mapping);
1108
1109         retval = p9_client_wstat(fid, &wstat);
1110         if (retval < 0)
1111                 return retval;
1112
1113         if ((iattr->ia_valid & ATTR_SIZE) &&
1114             iattr->ia_size != i_size_read(dentry->d_inode))
1115                 truncate_setsize(dentry->d_inode, iattr->ia_size);
1116
1117         v9fs_invalidate_inode_attr(dentry->d_inode);
1118
1119         setattr_copy(dentry->d_inode, iattr);
1120         mark_inode_dirty(dentry->d_inode);
1121         return 0;
1122 }
1123
1124 /**
1125  * v9fs_stat2inode - populate an inode structure with mistat info
1126  * @stat: Plan 9 metadata (mistat) structure
1127  * @inode: inode to populate
1128  * @sb: superblock of filesystem
1129  *
1130  */
1131
1132 void
1133 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1134         struct super_block *sb)
1135 {
1136         mode_t mode;
1137         char ext[32];
1138         char tag_name[14];
1139         unsigned int i_nlink;
1140         struct v9fs_session_info *v9ses = sb->s_fs_info;
1141         struct v9fs_inode *v9inode = V9FS_I(inode);
1142
1143         inode->i_nlink = 1;
1144
1145         inode->i_atime.tv_sec = stat->atime;
1146         inode->i_mtime.tv_sec = stat->mtime;
1147         inode->i_ctime.tv_sec = stat->mtime;
1148
1149         inode->i_uid = v9ses->dfltuid;
1150         inode->i_gid = v9ses->dfltgid;
1151
1152         if (v9fs_proto_dotu(v9ses)) {
1153                 inode->i_uid = stat->n_uid;
1154                 inode->i_gid = stat->n_gid;
1155         }
1156         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1157                 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1158                         /*
1159                          * Hadlink support got added later to
1160                          * to the .u extension. So there can be
1161                          * server out there that doesn't support
1162                          * this even with .u extension. So check
1163                          * for non NULL stat->extension
1164                          */
1165                         strncpy(ext, stat->extension, sizeof(ext));
1166                         /* HARDLINKCOUNT %u */
1167                         sscanf(ext, "%13s %u", tag_name, &i_nlink);
1168                         if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1169                                 inode->i_nlink = i_nlink;
1170                 }
1171         }
1172         mode = stat->mode & S_IALLUGO;
1173         mode |= inode->i_mode & ~S_IALLUGO;
1174         inode->i_mode = mode;
1175         i_size_write(inode, stat->length);
1176
1177         /* not real number of blocks, but 512 byte ones ... */
1178         inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1179         v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1180 }
1181
1182 /**
1183  * v9fs_qid2ino - convert qid into inode number
1184  * @qid: qid to hash
1185  *
1186  * BUG: potential for inode number collisions?
1187  */
1188
1189 ino_t v9fs_qid2ino(struct p9_qid *qid)
1190 {
1191         u64 path = qid->path + 2;
1192         ino_t i = 0;
1193
1194         if (sizeof(ino_t) == sizeof(path))
1195                 memcpy(&i, &path, sizeof(ino_t));
1196         else
1197                 i = (ino_t) (path ^ (path >> 32));
1198
1199         return i;
1200 }
1201
1202 /**
1203  * v9fs_readlink - read a symlink's location (internal version)
1204  * @dentry: dentry for symlink
1205  * @buffer: buffer to load symlink location into
1206  * @buflen: length of buffer
1207  *
1208  */
1209
1210 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1211 {
1212         int retval;
1213
1214         struct v9fs_session_info *v9ses;
1215         struct p9_fid *fid;
1216         struct p9_wstat *st;
1217
1218         P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1219         retval = -EPERM;
1220         v9ses = v9fs_dentry2v9ses(dentry);
1221         fid = v9fs_fid_lookup(dentry);
1222         if (IS_ERR(fid))
1223                 return PTR_ERR(fid);
1224
1225         if (!v9fs_proto_dotu(v9ses))
1226                 return -EBADF;
1227
1228         st = p9_client_stat(fid);
1229         if (IS_ERR(st))
1230                 return PTR_ERR(st);
1231
1232         if (!(st->mode & P9_DMSYMLINK)) {
1233                 retval = -EINVAL;
1234                 goto done;
1235         }
1236
1237         /* copy extension buffer into buffer */
1238         strncpy(buffer, st->extension, buflen);
1239
1240         P9_DPRINTK(P9_DEBUG_VFS,
1241                 "%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
1242
1243         retval = strnlen(buffer, buflen);
1244 done:
1245         p9stat_free(st);
1246         kfree(st);
1247         return retval;
1248 }
1249
1250 /**
1251  * v9fs_vfs_follow_link - follow a symlink path
1252  * @dentry: dentry for symlink
1253  * @nd: nameidata
1254  *
1255  */
1256
1257 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1258 {
1259         int len = 0;
1260         char *link = __getname();
1261
1262         P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
1263
1264         if (!link)
1265                 link = ERR_PTR(-ENOMEM);
1266         else {
1267                 len = v9fs_readlink(dentry, link, PATH_MAX);
1268
1269                 if (len < 0) {
1270                         __putname(link);
1271                         link = ERR_PTR(len);
1272                 } else
1273                         link[min(len, PATH_MAX-1)] = 0;
1274         }
1275         nd_set_link(nd, link);
1276
1277         return NULL;
1278 }
1279
1280 /**
1281  * v9fs_vfs_put_link - release a symlink path
1282  * @dentry: dentry for symlink
1283  * @nd: nameidata
1284  * @p: unused
1285  *
1286  */
1287
1288 void
1289 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1290 {
1291         char *s = nd_get_link(nd);
1292
1293         P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
1294                 IS_ERR(s) ? "<error>" : s);
1295         if (!IS_ERR(s))
1296                 __putname(s);
1297 }
1298
1299 /**
1300  * v9fs_vfs_mkspecial - create a special file
1301  * @dir: inode to create special file in
1302  * @dentry: dentry to create
1303  * @mode: mode to create special file
1304  * @extension: 9p2000.u format extension string representing special file
1305  *
1306  */
1307
1308 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1309         int mode, const char *extension)
1310 {
1311         u32 perm;
1312         struct p9_fid *fid;
1313         struct v9fs_session_info *v9ses;
1314
1315         v9ses = v9fs_inode2v9ses(dir);
1316         if (!v9fs_proto_dotu(v9ses)) {
1317                 P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1318                 return -EPERM;
1319         }
1320
1321         perm = unixmode2p9mode(v9ses, mode);
1322         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1323                                                                 P9_OREAD);
1324         if (IS_ERR(fid))
1325                 return PTR_ERR(fid);
1326
1327         v9fs_invalidate_inode_attr(dir);
1328         p9_client_clunk(fid);
1329         return 0;
1330 }
1331
1332 /**
1333  * v9fs_vfs_symlink - helper function to create symlinks
1334  * @dir: directory inode containing symlink
1335  * @dentry: dentry for symlink
1336  * @symname: symlink data
1337  *
1338  * See Also: 9P2000.u RFC for more information
1339  *
1340  */
1341
1342 static int
1343 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1344 {
1345         P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1346                                         dentry->d_name.name, symname);
1347
1348         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1349 }
1350
1351 /**
1352  * v9fs_vfs_link - create a hardlink
1353  * @old_dentry: dentry for file to link to
1354  * @dir: inode destination for new link
1355  * @dentry: dentry for link
1356  *
1357  */
1358
1359 static int
1360 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1361               struct dentry *dentry)
1362 {
1363         int retval;
1364         char *name;
1365         struct p9_fid *oldfid;
1366
1367         P9_DPRINTK(P9_DEBUG_VFS,
1368                 " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1369                 old_dentry->d_name.name);
1370
1371         oldfid = v9fs_fid_clone(old_dentry);
1372         if (IS_ERR(oldfid))
1373                 return PTR_ERR(oldfid);
1374
1375         name = __getname();
1376         if (unlikely(!name)) {
1377                 retval = -ENOMEM;
1378                 goto clunk_fid;
1379         }
1380
1381         sprintf(name, "%d\n", oldfid->fid);
1382         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1383         __putname(name);
1384         if (!retval) {
1385                 v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1386                 v9fs_invalidate_inode_attr(dir);
1387         }
1388 clunk_fid:
1389         p9_client_clunk(oldfid);
1390         return retval;
1391 }
1392
1393 /**
1394  * v9fs_vfs_mknod - create a special file
1395  * @dir: inode destination for new link
1396  * @dentry: dentry for file
1397  * @mode: mode for creation
1398  * @rdev: device associated with special file
1399  *
1400  */
1401
1402 static int
1403 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1404 {
1405         int retval;
1406         char *name;
1407
1408         P9_DPRINTK(P9_DEBUG_VFS,
1409                 " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1410                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1411
1412         if (!new_valid_dev(rdev))
1413                 return -EINVAL;
1414
1415         name = __getname();
1416         if (!name)
1417                 return -ENOMEM;
1418         /* build extension */
1419         if (S_ISBLK(mode))
1420                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1421         else if (S_ISCHR(mode))
1422                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1423         else if (S_ISFIFO(mode))
1424                 *name = 0;
1425         else if (S_ISSOCK(mode))
1426                 *name = 0;
1427         else {
1428                 __putname(name);
1429                 return -EINVAL;
1430         }
1431
1432         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1433         __putname(name);
1434
1435         return retval;
1436 }
1437
1438 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1439 {
1440         int umode;
1441         dev_t rdev;
1442         loff_t i_size;
1443         struct p9_wstat *st;
1444         struct v9fs_session_info *v9ses;
1445
1446         v9ses = v9fs_inode2v9ses(inode);
1447         st = p9_client_stat(fid);
1448         if (IS_ERR(st))
1449                 return PTR_ERR(st);
1450         /*
1451          * Don't update inode if the file type is different
1452          */
1453         umode = p9mode2unixmode(v9ses, st, &rdev);
1454         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1455                 goto out;
1456
1457         spin_lock(&inode->i_lock);
1458         /*
1459          * We don't want to refresh inode->i_size,
1460          * because we may have cached data
1461          */
1462         i_size = inode->i_size;
1463         v9fs_stat2inode(st, inode, inode->i_sb);
1464         if (v9ses->cache)
1465                 inode->i_size = i_size;
1466         spin_unlock(&inode->i_lock);
1467 out:
1468         p9stat_free(st);
1469         kfree(st);
1470         return 0;
1471 }
1472
1473 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1474         .create = v9fs_vfs_create,
1475         .lookup = v9fs_vfs_lookup,
1476         .symlink = v9fs_vfs_symlink,
1477         .link = v9fs_vfs_link,
1478         .unlink = v9fs_vfs_unlink,
1479         .mkdir = v9fs_vfs_mkdir,
1480         .rmdir = v9fs_vfs_rmdir,
1481         .mknod = v9fs_vfs_mknod,
1482         .rename = v9fs_vfs_rename,
1483         .getattr = v9fs_vfs_getattr,
1484         .setattr = v9fs_vfs_setattr,
1485 };
1486
1487 static const struct inode_operations v9fs_dir_inode_operations = {
1488         .create = v9fs_vfs_create,
1489         .lookup = v9fs_vfs_lookup,
1490         .unlink = v9fs_vfs_unlink,
1491         .mkdir = v9fs_vfs_mkdir,
1492         .rmdir = v9fs_vfs_rmdir,
1493         .mknod = v9fs_vfs_mknod,
1494         .rename = v9fs_vfs_rename,
1495         .getattr = v9fs_vfs_getattr,
1496         .setattr = v9fs_vfs_setattr,
1497 };
1498
1499 static const struct inode_operations v9fs_file_inode_operations = {
1500         .getattr = v9fs_vfs_getattr,
1501         .setattr = v9fs_vfs_setattr,
1502 };
1503
1504 static const struct inode_operations v9fs_symlink_inode_operations = {
1505         .readlink = generic_readlink,
1506         .follow_link = v9fs_vfs_follow_link,
1507         .put_link = v9fs_vfs_put_link,
1508         .getattr = v9fs_vfs_getattr,
1509         .setattr = v9fs_vfs_setattr,
1510 };
1511