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