fs/9p/vfs_inode.c

   1 /*
   2  *  linux/fs/9p/vfs_inode.c
   3  *
   4  * This file contains vfs inode ops for the 9P2000 protocol.
   5  *
   6  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/errno.h>
  30 #include <linux/fs.h>
  31 #include <linux/file.h>
  32 #include <linux/pagemap.h>
  33 #include <linux/stat.h>
  34 #include <linux/string.h>
  35 #include <linux/inet.h>
  36 #include <linux/namei.h>
  37 #include <linux/idr.h>
  38 #include <linux/sched.h>
  39 #include <linux/slab.h>
  40 #include <linux/xattr.h>
  41 #include <linux/posix_acl.h>
  42 #include <net/9p/9p.h>
  43 #include <net/9p/client.h>
  44
  45 #include "v9fs.h"
  46 #include "v9fs_vfs.h"
  47 #include "fid.h"
  48 #include "cache.h"
  49 #include "xattr.h"
  50 #include "acl.h"
  51
  52 static const struct inode_operations v9fs_dir_inode_operations;
  53 static const struct inode_operations v9fs_dir_inode_operations_dotu;
  54 static const struct inode_operations v9fs_file_inode_operations;
  55 static const struct inode_operations v9fs_symlink_inode_operations;
  56
  57 /**
  58  * unixmode2p9mode - convert unix mode bits to plan 9
  59  * @v9ses: v9fs session information
  60  * @mode: mode to convert
  61  *
  62  */
  63
  64 static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode)
  65 {
  66         int res;
  67         res = mode & 0777;
  68         if (S_ISDIR(mode))
  69                 res |= P9_DMDIR;
  70         if (v9fs_proto_dotu(v9ses)) {
  71                 if (v9ses->nodev == 0) {
  72                         if (S_ISSOCK(mode))
  73                                 res |= P9_DMSOCKET;
  74                         if (S_ISFIFO(mode))
  75                                 res |= P9_DMNAMEDPIPE;
  76                         if (S_ISBLK(mode))
  77                                 res |= P9_DMDEVICE;
  78                         if (S_ISCHR(mode))
  79                                 res |= P9_DMDEVICE;
  80                 }
  81
  82                 if ((mode & S_ISUID) == S_ISUID)
  83                         res |= P9_DMSETUID;
  84                 if ((mode & S_ISGID) == S_ISGID)
  85                         res |= P9_DMSETGID;
  86                 if ((mode & S_ISVTX) == S_ISVTX)
  87                         res |= P9_DMSETVTX;
  88         }
  89         return res;
  90 }
  91
  92 /**
  93  * p9mode2perm- convert plan9 mode bits to unix permission bits
  94  * @v9ses: v9fs session information
  95  * @stat: p9_wstat from which mode need to be derived
  96  *
  97  */
  98 static int p9mode2perm(struct v9fs_session_info *v9ses,
  99                        struct p9_wstat *stat)
 100 {
 101         int res;
 102         int mode = stat->mode;
 103
 104         res = mode & S_IALLUGO;
 105         if (v9fs_proto_dotu(v9ses)) {
 106                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
 107                         res |= S_ISUID;
 108
 109                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
 110                         res |= S_ISGID;
 111
 112                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 113                         res |= S_ISVTX;
 114         }
 115         return res;
 116 }
 117
 118 /**
 119  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
 120  * @v9ses: v9fs session information
 121  * @stat: p9_wstat from which mode need to be derived
 122  * @rdev: major number, minor number in case of device files.
 123  *
 124  */
 125 static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses,
 126                                struct p9_wstat *stat, dev_t *rdev)
 127 {
 128         int res;
 129         u32 mode = stat->mode;
 130
 131         *rdev = 0;
 132         res = p9mode2perm(v9ses, stat);
 133
 134         if ((mode & P9_DMDIR) == P9_DMDIR)
 135                 res |= S_IFDIR;
 136         else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 137                 res |= S_IFLNK;
 138         else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 139                  && (v9ses->nodev == 0))
 140                 res |= S_IFSOCK;
 141         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 142                  && (v9ses->nodev == 0))
 143                 res |= S_IFIFO;
 144         else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 145                  && (v9ses->nodev == 0)) {
 146                 char type = 0, ext[32];
 147                 int major = -1, minor = -1;
 148
 149                 strlcpy(ext, stat->extension, sizeof(ext));
 150                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 151                 switch (type) {
 152                 case 'c':
 153                         res |= S_IFCHR;
 154                         break;
 155                 case 'b':
 156                         res |= S_IFBLK;
 157                         break;
 158                 default:
 159                         p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
 160                                  type, stat->extension);
 161                 };
 162                 *rdev = MKDEV(major, minor);
 163         } else
 164                 res |= S_IFREG;
 165
 166         return res;
 167 }
 168
 169 /**
 170  * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 171  * @uflags: flags to convert
 172  * @extended: if .u extensions are active
 173  */
 174
 175 int v9fs_uflags2omode(int uflags, int extended)
 176 {
 177         int ret;
 178
 179         ret = 0;
 180         switch (uflags&3) {
 181         default:
 182         case O_RDONLY:
 183                 ret = P9_OREAD;
 184                 break;
 185
 186         case O_WRONLY:
 187                 ret = P9_OWRITE;
 188                 break;
 189
 190         case O_RDWR:
 191                 ret = P9_ORDWR;
 192                 break;
 193         }
 194
 195         if (extended) {
 196                 if (uflags & O_EXCL)
 197                         ret |= P9_OEXCL;
 198
 199                 if (uflags & O_APPEND)
 200                         ret |= P9_OAPPEND;
 201         }
 202
 203         return ret;
 204 }
 205
 206 /**
 207  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 208  * @wstat: structure to initialize
 209  *
 210  */
 211
 212 void
 213 v9fs_blank_wstat(struct p9_wstat *wstat)
 214 {
 215         wstat->type = ~0;
 216         wstat->dev = ~0;
 217         wstat->qid.type = ~0;
 218         wstat->qid.version = ~0;
 219         *((long long *)&wstat->qid.path) = ~0;
 220         wstat->mode = ~0;
 221         wstat->atime = ~0;
 222         wstat->mtime = ~0;
 223         wstat->length = ~0;
 224         wstat->name = NULL;
 225         wstat->uid = NULL;
 226         wstat->gid = NULL;
 227         wstat->muid = NULL;
 228         wstat->n_uid = INVALID_UID;
 229         wstat->n_gid = INVALID_GID;
 230         wstat->n_muid = INVALID_UID;
 231         wstat->extension = NULL;
 232 }
 233
 234 /**
 235  * v9fs_alloc_inode - helper function to allocate an inode
 236  *
 237  */
 238 struct inode *v9fs_alloc_inode(struct super_block *sb)
 239 {
 240         struct v9fs_inode *v9inode;
 241         v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 242                                                         GFP_KERNEL);
 243         if (!v9inode)
 244                 return NULL;
 245 #ifdef CONFIG_9P_FSCACHE
 246         v9inode->fscache = NULL;
 247         spin_lock_init(&v9inode->fscache_lock);
 248 #endif
 249         v9inode->writeback_fid = NULL;
 250         v9inode->cache_validity = 0;
 251         mutex_init(&v9inode->v_mutex);
 252         return &v9inode->vfs_inode;
 253 }
 254
 255 /**
 256  * v9fs_destroy_inode - destroy an inode
 257  *
 258  */
 259
 260 static void v9fs_i_callback(struct rcu_head *head)
 261 {
 262         struct inode *inode = container_of(head, struct inode, i_rcu);
 263         kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 264 }
 265
 266 void v9fs_destroy_inode(struct inode *inode)
 267 {
 268         call_rcu(&inode->i_rcu, v9fs_i_callback);
 269 }
 270
 271 int v9fs_init_inode(struct v9fs_session_info *v9ses,
 272                     struct inode *inode, umode_t mode, dev_t rdev)
 273 {
 274         int err = 0;
 275
 276         inode_init_owner(inode, NULL, mode);
 277         inode->i_blocks = 0;
 278         inode->i_rdev = rdev;
 279         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 280         inode->i_mapping->a_ops = &v9fs_addr_operations;
 281
 282         switch (mode & S_IFMT) {
 283         case S_IFIFO:
 284         case S_IFBLK:
 285         case S_IFCHR:
 286         case S_IFSOCK:
 287                 if (v9fs_proto_dotl(v9ses)) {
 288                         inode->i_op = &v9fs_file_inode_operations_dotl;
 289                 } else if (v9fs_proto_dotu(v9ses)) {
 290                         inode->i_op = &v9fs_file_inode_operations;
 291                 } else {
 292                         p9_debug(P9_DEBUG_ERROR,
 293                                  "special files without extended mode\n");
 294                         err = -EINVAL;
 295                         goto error;
 296                 }
 297                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 298                 break;
 299         case S_IFREG:
 300                 if (v9fs_proto_dotl(v9ses)) {
 301                         inode->i_op = &v9fs_file_inode_operations_dotl;
 302                         if (v9ses->cache)
 303                                 inode->i_fop =
 304                                         &v9fs_cached_file_operations_dotl;
 305                         else
 306                                 inode->i_fop = &v9fs_file_operations_dotl;
 307                 } else {
 308                         inode->i_op = &v9fs_file_inode_operations;
 309                         if (v9ses->cache)
 310                                 inode->i_fop = &v9fs_cached_file_operations;
 311                         else
 312                                 inode->i_fop = &v9fs_file_operations;
 313                 }
 314
 315                 break;
 316         case S_IFLNK:
 317                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 318                         p9_debug(P9_DEBUG_ERROR,
 319                                  "extended modes used with legacy protocol\n");
 320                         err = -EINVAL;
 321                         goto error;
 322                 }
 323
 324                 if (v9fs_proto_dotl(v9ses))
 325                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
 326                 else
 327                         inode->i_op = &v9fs_symlink_inode_operations;
 328
 329                 break;
 330         case S_IFDIR:
 331                 inc_nlink(inode);
 332                 if (v9fs_proto_dotl(v9ses))
 333                         inode->i_op = &v9fs_dir_inode_operations_dotl;
 334                 else if (v9fs_proto_dotu(v9ses))
 335                         inode->i_op = &v9fs_dir_inode_operations_dotu;
 336                 else
 337                         inode->i_op = &v9fs_dir_inode_operations;
 338
 339                 if (v9fs_proto_dotl(v9ses))
 340                         inode->i_fop = &v9fs_dir_operations_dotl;
 341                 else
 342                         inode->i_fop = &v9fs_dir_operations;
 343
 344                 break;
 345         default:
 346                 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n",
 347                          mode, mode & S_IFMT);
 348                 err = -EINVAL;
 349                 goto error;
 350         }
 351 error:
 352         return err;
 353
 354 }
 355
 356 /**
 357  * v9fs_get_inode - helper function to setup an inode
 358  * @sb: superblock
 359  * @mode: mode to setup inode with
 360  *
 361  */
 362
 363 struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev)
 364 {
 365         int err;
 366         struct inode *inode;
 367         struct v9fs_session_info *v9ses = sb->s_fs_info;
 368
 369         p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode);
 370
 371         inode = new_inode(sb);
 372         if (!inode) {
 373                 pr_warn("%s (%d): Problem allocating inode\n",
 374                         __func__, task_pid_nr(current));
 375                 return ERR_PTR(-ENOMEM);
 376         }
 377         err = v9fs_init_inode(v9ses, inode, mode, rdev);
 378         if (err) {
 379                 iput(inode);
 380                 return ERR_PTR(err);
 381         }
 382         return inode;
 383 }
 384
 385 /*
 386 static struct v9fs_fid*
 387 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 388 {
 389         int err;
 390         int nfid;
 391         struct v9fs_fid *ret;
 392         struct v9fs_fcall *fcall;
 393
 394         nfid = v9fs_get_idpool(&v9ses->fidpool);
 395         if (nfid < 0) {
 396                 eprintk(KERN_WARNING, "no free fids available\n");
 397                 return ERR_PTR(-ENOSPC);
 398         }
 399
 400         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 401                 &fcall);
 402
 403         if (err < 0) {
 404                 if (fcall && fcall->id == RWALK)
 405                         goto clunk_fid;
 406
 407                 PRINT_FCALL_ERROR("walk error", fcall);
 408                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 409                 goto error;
 410         }
 411
 412         kfree(fcall);
 413         fcall = NULL;
 414         ret = v9fs_fid_create(v9ses, nfid);
 415         if (!ret) {
 416                 err = -ENOMEM;
 417                 goto clunk_fid;
 418         }
 419
 420         err = v9fs_fid_insert(ret, dentry);
 421         if (err < 0) {
 422                 v9fs_fid_destroy(ret);
 423                 goto clunk_fid;
 424         }
 425
 426         return ret;
 427
 428 clunk_fid:
 429         v9fs_t_clunk(v9ses, nfid);
 430
 431 error:
 432         kfree(fcall);
 433         return ERR_PTR(err);
 434 }
 435 */
 436
 437
 438 /**
 439  * v9fs_clear_inode - release an inode
 440  * @inode: inode to release
 441  *
 442  */
 443 void v9fs_evict_inode(struct inode *inode)
 444 {
 445         struct v9fs_inode *v9inode = V9FS_I(inode);
 446
 447         truncate_inode_pages(inode->i_mapping, 0);
 448         clear_inode(inode);
 449         filemap_fdatawrite(inode->i_mapping);
 450
 451         v9fs_cache_inode_put_cookie(inode);
 452         /* clunk the fid stashed in writeback_fid */
 453         if (v9inode->writeback_fid) {
 454                 p9_client_clunk(v9inode->writeback_fid);
 455                 v9inode->writeback_fid = NULL;
 456         }
 457 }
 458
 459 static int v9fs_test_inode(struct inode *inode, void *data)
 460 {
 461         int umode;
 462         dev_t rdev;
 463         struct v9fs_inode *v9inode = V9FS_I(inode);
 464         struct p9_wstat *st = (struct p9_wstat *)data;
 465         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 466
 467         umode = p9mode2unixmode(v9ses, st, &rdev);
 468         /* don't match inode of different type */
 469         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 470                 return 0;
 471
 472         /* compare qid details */
 473         if (memcmp(&v9inode->qid.version,
 474                    &st->qid.version, sizeof(v9inode->qid.version)))
 475                 return 0;
 476
 477         if (v9inode->qid.type != st->qid.type)
 478                 return 0;
 479         return 1;
 480 }
 481
 482 static int v9fs_test_new_inode(struct inode *inode, void *data)
 483 {
 484         return 0;
 485 }
 486
 487 static int v9fs_set_inode(struct inode *inode,  void *data)
 488 {
 489         struct v9fs_inode *v9inode = V9FS_I(inode);
 490         struct p9_wstat *st = (struct p9_wstat *)data;
 491
 492         memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 493         return 0;
 494 }
 495
 496 static struct inode *v9fs_qid_iget(struct super_block *sb,
 497                                    struct p9_qid *qid,
 498                                    struct p9_wstat *st,
 499                                    int new)
 500 {
 501         dev_t rdev;
 502         int retval;
 503         umode_t umode;
 504         unsigned long i_ino;
 505         struct inode *inode;
 506         struct v9fs_session_info *v9ses = sb->s_fs_info;
 507         int (*test)(struct inode *, void *);
 508
 509         if (new)
 510                 test = v9fs_test_new_inode;
 511         else
 512                 test = v9fs_test_inode;
 513
 514         i_ino = v9fs_qid2ino(qid);
 515         inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 516         if (!inode)
 517                 return ERR_PTR(-ENOMEM);
 518         if (!(inode->i_state & I_NEW))
 519                 return inode;
 520         /*
 521          * initialize the inode with the stat info
 522          * FIXME!! we may need support for stale inodes
 523          * later.
 524          */
 525         inode->i_ino = i_ino;
 526         umode = p9mode2unixmode(v9ses, st, &rdev);
 527         retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 528         if (retval)
 529                 goto error;
 530
 531         v9fs_stat2inode(st, inode, sb);
 532         v9fs_cache_inode_get_cookie(inode);
 533         unlock_new_inode(inode);
 534         return inode;
 535 error:
 536         unlock_new_inode(inode);
 537         iput(inode);
 538         return ERR_PTR(retval);
 539
 540 }
 541
 542 struct inode *
 543 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 544                     struct super_block *sb, int new)
 545 {
 546         struct p9_wstat *st;
 547         struct inode *inode = NULL;
 548
 549         st = p9_client_stat(fid);
 550         if (IS_ERR(st))
 551                 return ERR_CAST(st);
 552
 553         inode = v9fs_qid_iget(sb, &st->qid, st, new);
 554         p9stat_free(st);
 555         kfree(st);
 556         return inode;
 557 }
 558
 559 /**
 560  * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 561  * plan 9 AT flag.
 562  * @flags: flags to convert
 563  */
 564 static int v9fs_at_to_dotl_flags(int flags)
 565 {
 566         int rflags = 0;
 567         if (flags & AT_REMOVEDIR)
 568                 rflags |= P9_DOTL_AT_REMOVEDIR;
 569         return rflags;
 570 }
 571
 572 /**
 573  * v9fs_remove - helper function to remove files and directories
 574  * @dir: directory inode that is being deleted
 575  * @dentry:  dentry that is being deleted
 576  * @rmdir: removing a directory
 577  *
 578  */
 579
 580 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 581 {
 582         struct inode *inode;
 583         int retval = -EOPNOTSUPP;
 584         struct p9_fid *v9fid, *dfid;
 585         struct v9fs_session_info *v9ses;
 586
 587         p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 588                  dir, dentry, flags);
 589
 590         v9ses = v9fs_inode2v9ses(dir);
 591         inode = dentry->d_inode;
 592         dfid = v9fs_fid_lookup(dentry->d_parent);
 593         if (IS_ERR(dfid)) {
 594                 retval = PTR_ERR(dfid);
 595                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 596                 return retval;
 597         }
 598         if (v9fs_proto_dotl(v9ses))
 599                 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 600                                             v9fs_at_to_dotl_flags(flags));
 601         if (retval == -EOPNOTSUPP) {
 602                 /* Try the one based on path */
 603                 v9fid = v9fs_fid_clone(dentry);
 604                 if (IS_ERR(v9fid))
 605                         return PTR_ERR(v9fid);
 606                 retval = p9_client_remove(v9fid);
 607         }
 608         if (!retval) {
 609                 /*
 610                  * directories on unlink should have zero
 611                  * link count
 612                  */
 613                 if (flags & AT_REMOVEDIR) {
 614                         clear_nlink(inode);
 615                         drop_nlink(dir);
 616                 } else
 617                         drop_nlink(inode);
 618
 619                 v9fs_invalidate_inode_attr(inode);
 620                 v9fs_invalidate_inode_attr(dir);
 621         }
 622         return retval;
 623 }
 624
 625 /**
 626  * v9fs_create - Create a file
 627  * @v9ses: session information
 628  * @dir: directory that dentry is being created in
 629  * @dentry:  dentry that is being created
 630  * @extension: 9p2000.u extension string to support devices, etc.
 631  * @perm: create permissions
 632  * @mode: open mode
 633  *
 634  */
 635 static struct p9_fid *
 636 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 637                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 638 {
 639         int err;
 640         char *name;
 641         struct p9_fid *dfid, *ofid, *fid;
 642         struct inode *inode;
 643
 644         p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 645
 646         err = 0;
 647         ofid = NULL;
 648         fid = NULL;
 649         name = (char *) dentry->d_name.name;
 650         dfid = v9fs_fid_lookup(dentry->d_parent);
 651         if (IS_ERR(dfid)) {
 652                 err = PTR_ERR(dfid);
 653                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 654                 return ERR_PTR(err);
 655         }
 656
 657         /* clone a fid to use for creation */
 658         ofid = p9_client_walk(dfid, 0, NULL, 1);
 659         if (IS_ERR(ofid)) {
 660                 err = PTR_ERR(ofid);
 661                 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 662                 return ERR_PTR(err);
 663         }
 664
 665         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 666         if (err < 0) {
 667                 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 668                 goto error;
 669         }
 670
 671         if (!(perm & P9_DMLINK)) {
 672                 /* now walk from the parent so we can get unopened fid */
 673                 fid = p9_client_walk(dfid, 1, &name, 1);
 674                 if (IS_ERR(fid)) {
 675                         err = PTR_ERR(fid);
 676                         p9_debug(P9_DEBUG_VFS,
 677                                    "p9_client_walk failed %d\n", err);
 678                         fid = NULL;
 679                         goto error;
 680                 }
 681                 /*
 682                  * instantiate inode and assign the unopened fid to the dentry
 683                  */
 684                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 685                 if (IS_ERR(inode)) {
 686                         err = PTR_ERR(inode);
 687                         p9_debug(P9_DEBUG_VFS,
 688                                    "inode creation failed %d\n", err);
 689                         goto error;
 690                 }
 691                 v9fs_fid_add(dentry, fid);
 692                 d_instantiate(dentry, inode);
 693         }
 694         return ofid;
 695 error:
 696         if (ofid)
 697                 p9_client_clunk(ofid);
 698
 699         if (fid)
 700                 p9_client_clunk(fid);
 701
 702         return ERR_PTR(err);
 703 }
 704
 705 /**
 706  * v9fs_vfs_create - VFS hook to create a regular file
 707  *
 708  * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
 709  * for mknod(2).
 710  *
 711  * @dir: directory inode that is being created
 712  * @dentry:  dentry that is being deleted
 713  * @mode: create permissions
 714  *
 715  */
 716
 717 static int
 718 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 719                 bool excl)
 720 {
 721         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 722         u32 perm = unixmode2p9mode(v9ses, mode);
 723         struct p9_fid *fid;
 724
 725         /* P9_OEXCL? */
 726         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR);
 727         if (IS_ERR(fid))
 728                 return PTR_ERR(fid);
 729
 730         v9fs_invalidate_inode_attr(dir);
 731         p9_client_clunk(fid);
 732
 733         return 0;
 734 }
 735
 736 /**
 737  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 738  * @dir:  inode that is being unlinked
 739  * @dentry: dentry that is being unlinked
 740  * @mode: mode for new directory
 741  *
 742  */
 743
 744 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
 745 {
 746         int err;
 747         u32 perm;
 748         struct p9_fid *fid;
 749         struct v9fs_session_info *v9ses;
 750
 751         p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 752         err = 0;
 753         v9ses = v9fs_inode2v9ses(dir);
 754         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 755         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 756         if (IS_ERR(fid)) {
 757                 err = PTR_ERR(fid);
 758                 fid = NULL;
 759         } else {
 760                 inc_nlink(dir);
 761                 v9fs_invalidate_inode_attr(dir);
 762         }
 763
 764         if (fid)
 765                 p9_client_clunk(fid);
 766
 767         return err;
 768 }
 769
 770 /**
 771  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 772  * @dir:  inode that is being walked from
 773  * @dentry: dentry that is being walked to?
 774  * @nameidata: path data
 775  *
 776  */
 777
 778 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 779                                       unsigned int flags)
 780 {
 781         struct dentry *res;
 782         struct super_block *sb;
 783         struct v9fs_session_info *v9ses;
 784         struct p9_fid *dfid, *fid;
 785         struct inode *inode;
 786         char *name;
 787
 788         p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p flags: %x\n",
 789                  dir, dentry->d_name.name, dentry, flags);
 790
 791         if (dentry->d_name.len > NAME_MAX)
 792                 return ERR_PTR(-ENAMETOOLONG);
 793
 794         sb = dir->i_sb;
 795         v9ses = v9fs_inode2v9ses(dir);
 796         /* We can walk d_parent because we hold the dir->i_mutex */
 797         dfid = v9fs_fid_lookup(dentry->d_parent);
 798         if (IS_ERR(dfid))
 799                 return ERR_CAST(dfid);
 800
 801         name = (char *) dentry->d_name.name;
 802         fid = p9_client_walk(dfid, 1, &name, 1);
 803         if (IS_ERR(fid)) {
 804                 if (fid == ERR_PTR(-ENOENT)) {
 805                         d_add(dentry, NULL);
 806                         return NULL;
 807                 }
 808                 return ERR_CAST(fid);
 809         }
 810         /*
 811          * Make sure we don't use a wrong inode due to parallel
 812          * unlink. For cached mode create calls request for new
 813          * inode. But with cache disabled, lookup should do this.
 814          */
 815         if (v9ses->cache)
 816                 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 817         else
 818                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 819         if (IS_ERR(inode)) {
 820                 p9_client_clunk(fid);
 821                 return ERR_CAST(inode);
 822         }
 823         /*
 824          * If we had a rename on the server and a parallel lookup
 825          * for the new name, then make sure we instantiate with
 826          * the new name. ie look up for a/b, while on server somebody
 827          * moved b under k and client parallely did a lookup for
 828          * k/b.
 829          */
 830         res = d_materialise_unique(dentry, inode);
 831         if (!res)
 832                 v9fs_fid_add(dentry, fid);
 833         else if (!IS_ERR(res))
 834                 v9fs_fid_add(res, fid);
 835         else
 836                 p9_client_clunk(fid);
 837         return res;
 838 }
 839
 840 static int
 841 v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry,
 842                      struct file *file, unsigned flags, umode_t mode,
 843                      int *opened)
 844 {
 845         int err;
 846         u32 perm;
 847         struct v9fs_inode *v9inode;
 848         struct v9fs_session_info *v9ses;
 849         struct p9_fid *fid, *inode_fid;
 850         struct dentry *res = NULL;
 851
 852         if (d_unhashed(dentry)) {
 853                 res = v9fs_vfs_lookup(dir, dentry, 0);
 854                 if (IS_ERR(res))
 855                         return PTR_ERR(res);
 856
 857                 if (res)
 858                         dentry = res;
 859         }
 860
 861         /* Only creates */
 862         if (!(flags & O_CREAT) || dentry->d_inode)
 863                 return finish_no_open(file, res);
 864
 865         err = 0;
 866         fid = NULL;
 867         v9ses = v9fs_inode2v9ses(dir);
 868         perm = unixmode2p9mode(v9ses, mode);
 869         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 870                                 v9fs_uflags2omode(flags,
 871                                                 v9fs_proto_dotu(v9ses)));
 872         if (IS_ERR(fid)) {
 873                 err = PTR_ERR(fid);
 874                 fid = NULL;
 875                 goto error;
 876         }
 877
 878         v9fs_invalidate_inode_attr(dir);
 879         v9inode = V9FS_I(dentry->d_inode);
 880         mutex_lock(&v9inode->v_mutex);
 881         if (v9ses->cache && !v9inode->writeback_fid &&
 882             ((flags & O_ACCMODE) != O_RDONLY)) {
 883                 /*
 884                  * clone a fid and add it to writeback_fid
 885                  * we do it during open time instead of
 886                  * page dirty time via write_begin/page_mkwrite
 887                  * because we want write after unlink usecase
 888                  * to work.
 889                  */
 890                 inode_fid = v9fs_writeback_fid(dentry);
 891                 if (IS_ERR(inode_fid)) {
 892                         err = PTR_ERR(inode_fid);
 893                         mutex_unlock(&v9inode->v_mutex);
 894                         goto error;
 895                 }
 896                 v9inode->writeback_fid = (void *) inode_fid;
 897         }
 898         mutex_unlock(&v9inode->v_mutex);
 899         err = finish_open(file, dentry, generic_file_open, opened);
 900         if (err)
 901                 goto error;
 902
 903         file->private_data = fid;
 904         if (v9ses->cache)
 905                 v9fs_cache_inode_set_cookie(dentry->d_inode, file);
 906
 907         *opened |= FILE_CREATED;
 908 out:
 909         dput(res);
 910         return err;
 911
 912 error:
 913         if (fid)
 914                 p9_client_clunk(fid);
 915         goto out;
 916 }
 917
 918 /**
 919  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 920  * @i:  inode that is being unlinked
 921  * @d: dentry that is being unlinked
 922  *
 923  */
 924
 925 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 926 {
 927         return v9fs_remove(i, d, 0);
 928 }
 929
 930 /**
 931  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 932  * @i:  inode that is being unlinked
 933  * @d: dentry that is being unlinked
 934  *
 935  */
 936
 937 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 938 {
 939         return v9fs_remove(i, d, AT_REMOVEDIR);
 940 }
 941
 942 /**
 943  * v9fs_vfs_rename - VFS hook to rename an inode
 944  * @old_dir:  old dir inode
 945  * @old_dentry: old dentry
 946  * @new_dir: new dir inode
 947  * @new_dentry: new dentry
 948  *
 949  */
 950
 951 int
 952 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 953                 struct inode *new_dir, struct dentry *new_dentry)
 954 {
 955         int retval;
 956         struct inode *old_inode;
 957         struct inode *new_inode;
 958         struct v9fs_session_info *v9ses;
 959         struct p9_fid *oldfid;
 960         struct p9_fid *olddirfid;
 961         struct p9_fid *newdirfid;
 962         struct p9_wstat wstat;
 963
 964         p9_debug(P9_DEBUG_VFS, "\n");
 965         retval = 0;
 966         old_inode = old_dentry->d_inode;
 967         new_inode = new_dentry->d_inode;
 968         v9ses = v9fs_inode2v9ses(old_inode);
 969         oldfid = v9fs_fid_lookup(old_dentry);
 970         if (IS_ERR(oldfid))
 971                 return PTR_ERR(oldfid);
 972
 973         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 974         if (IS_ERR(olddirfid)) {
 975                 retval = PTR_ERR(olddirfid);
 976                 goto done;
 977         }
 978
 979         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 980         if (IS_ERR(newdirfid)) {
 981                 retval = PTR_ERR(newdirfid);
 982                 goto clunk_olddir;
 983         }
 984
 985         down_write(&v9ses->rename_sem);
 986         if (v9fs_proto_dotl(v9ses)) {
 987                 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 988                                             newdirfid, new_dentry->d_name.name);
 989                 if (retval == -EOPNOTSUPP)
 990                         retval = p9_client_rename(oldfid, newdirfid,
 991                                                   new_dentry->d_name.name);
 992                 if (retval != -EOPNOTSUPP)
 993                         goto clunk_newdir;
 994         }
 995         if (old_dentry->d_parent != new_dentry->d_parent) {
 996                 /*
 997                  * 9P .u can only handle file rename in the same directory
 998                  */
 999
1000                 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
1001                 retval = -EXDEV;
1002                 goto clunk_newdir;
1003         }
1004         v9fs_blank_wstat(&wstat);
1005         wstat.muid = v9ses->uname;
1006         wstat.name = (char *) new_dentry->d_name.name;
1007         retval = p9_client_wstat(oldfid, &wstat);
1008
1009 clunk_newdir:
1010         if (!retval) {
1011                 if (new_inode) {
1012                         if (S_ISDIR(new_inode->i_mode))
1013                                 clear_nlink(new_inode);
1014                         else
1015                                 drop_nlink(new_inode);
1016                 }
1017                 if (S_ISDIR(old_inode->i_mode)) {
1018                         if (!new_inode)
1019                                 inc_nlink(new_dir);
1020                         drop_nlink(old_dir);
1021                 }
1022                 v9fs_invalidate_inode_attr(old_inode);
1023                 v9fs_invalidate_inode_attr(old_dir);
1024                 v9fs_invalidate_inode_attr(new_dir);
1025
1026                 /* successful rename */
1027                 d_move(old_dentry, new_dentry);
1028         }
1029         up_write(&v9ses->rename_sem);
1030         p9_client_clunk(newdirfid);
1031
1032 clunk_olddir:
1033         p9_client_clunk(olddirfid);
1034
1035 done:
1036         return retval;
1037 }
1038
1039 /**
1040  * v9fs_vfs_getattr - retrieve file metadata
1041  * @mnt: mount information
1042  * @dentry: file to get attributes on
1043  * @stat: metadata structure to populate
1044  *
1045  */
1046
1047 static int
1048 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1049                  struct kstat *stat)
1050 {
1051         struct v9fs_session_info *v9ses;
1052         struct p9_fid *fid;
1053         struct p9_wstat *st;
1054
1055         p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1056         v9ses = v9fs_dentry2v9ses(dentry);
1057         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1058                 generic_fillattr(dentry->d_inode, stat);
1059                 return 0;
1060         }
1061         fid = v9fs_fid_lookup(dentry);
1062         if (IS_ERR(fid))
1063                 return PTR_ERR(fid);
1064
1065         st = p9_client_stat(fid);
1066         if (IS_ERR(st))
1067                 return PTR_ERR(st);
1068
1069         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1070         generic_fillattr(dentry->d_inode, stat);
1071
1072         p9stat_free(st);
1073         kfree(st);
1074         return 0;
1075 }
1076
1077 /**
1078  * v9fs_vfs_setattr - set file metadata
1079  * @dentry: file whose metadata to set
1080  * @iattr: metadata assignment structure
1081  *
1082  */
1083
1084 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1085 {
1086         int retval;
1087         struct v9fs_session_info *v9ses;
1088         struct p9_fid *fid;
1089         struct p9_wstat wstat;
1090
1091         p9_debug(P9_DEBUG_VFS, "\n");
1092         retval = inode_change_ok(dentry->d_inode, iattr);
1093         if (retval)
1094                 return retval;
1095
1096         retval = -EPERM;
1097         v9ses = v9fs_dentry2v9ses(dentry);
1098         fid = v9fs_fid_lookup(dentry);
1099         if(IS_ERR(fid))
1100                 return PTR_ERR(fid);
1101
1102         v9fs_blank_wstat(&wstat);
1103         if (iattr->ia_valid & ATTR_MODE)
1104                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1105
1106         if (iattr->ia_valid & ATTR_MTIME)
1107                 wstat.mtime = iattr->ia_mtime.tv_sec;
1108
1109         if (iattr->ia_valid & ATTR_ATIME)
1110                 wstat.atime = iattr->ia_atime.tv_sec;
1111
1112         if (iattr->ia_valid & ATTR_SIZE)
1113                 wstat.length = iattr->ia_size;
1114
1115         if (v9fs_proto_dotu(v9ses)) {
1116                 if (iattr->ia_valid & ATTR_UID)
1117                         wstat.n_uid = iattr->ia_uid;
1118
1119                 if (iattr->ia_valid & ATTR_GID)
1120                         wstat.n_gid = iattr->ia_gid;
1121         }
1122
1123         /* Write all dirty data */
1124         if (S_ISREG(dentry->d_inode->i_mode))
1125                 filemap_write_and_wait(dentry->d_inode->i_mapping);
1126
1127         retval = p9_client_wstat(fid, &wstat);
1128         if (retval < 0)
1129                 return retval;
1130
1131         if ((iattr->ia_valid & ATTR_SIZE) &&
1132             iattr->ia_size != i_size_read(dentry->d_inode))
1133                 truncate_setsize(dentry->d_inode, iattr->ia_size);
1134
1135         v9fs_invalidate_inode_attr(dentry->d_inode);
1136
1137         setattr_copy(dentry->d_inode, iattr);
1138         mark_inode_dirty(dentry->d_inode);
1139         return 0;
1140 }
1141
1142 /**
1143  * v9fs_stat2inode - populate an inode structure with mistat info
1144  * @stat: Plan 9 metadata (mistat) structure
1145  * @inode: inode to populate
1146  * @sb: superblock of filesystem
1147  *
1148  */
1149
1150 void
1151 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1152         struct super_block *sb)
1153 {
1154         umode_t mode;
1155         char ext[32];
1156         char tag_name[14];
1157         unsigned int i_nlink;
1158         struct v9fs_session_info *v9ses = sb->s_fs_info;
1159         struct v9fs_inode *v9inode = V9FS_I(inode);
1160
1161         set_nlink(inode, 1);
1162
1163         inode->i_atime.tv_sec = stat->atime;
1164         inode->i_mtime.tv_sec = stat->mtime;
1165         inode->i_ctime.tv_sec = stat->mtime;
1166
1167         inode->i_uid = v9ses->dfltuid;
1168         inode->i_gid = v9ses->dfltgid;
1169
1170         if (v9fs_proto_dotu(v9ses)) {
1171                 inode->i_uid = stat->n_uid;
1172                 inode->i_gid = stat->n_gid;
1173         }
1174         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1175                 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1176                         /*
1177                          * Hadlink support got added later to
1178                          * to the .u extension. So there can be
1179                          * server out there that doesn't support
1180                          * this even with .u extension. So check
1181                          * for non NULL stat->extension
1182                          */
1183                         strlcpy(ext, stat->extension, sizeof(ext));
1184                         /* HARDLINKCOUNT %u */
1185                         sscanf(ext, "%13s %u", tag_name, &i_nlink);
1186                         if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1187                                 set_nlink(inode, i_nlink);
1188                 }
1189         }
1190         mode = p9mode2perm(v9ses, stat);
1191         mode |= inode->i_mode & ~S_IALLUGO;
1192         inode->i_mode = mode;
1193         i_size_write(inode, stat->length);
1194
1195         /* not real number of blocks, but 512 byte ones ... */
1196         inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1197         v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1198 }
1199
1200 /**
1201  * v9fs_qid2ino - convert qid into inode number
1202  * @qid: qid to hash
1203  *
1204  * BUG: potential for inode number collisions?
1205  */
1206
1207 ino_t v9fs_qid2ino(struct p9_qid *qid)
1208 {
1209         u64 path = qid->path + 2;
1210         ino_t i = 0;
1211
1212         if (sizeof(ino_t) == sizeof(path))
1213                 memcpy(&i, &path, sizeof(ino_t));
1214         else
1215                 i = (ino_t) (path ^ (path >> 32));
1216
1217         return i;
1218 }
1219
1220 /**
1221  * v9fs_readlink - read a symlink's location (internal version)
1222  * @dentry: dentry for symlink
1223  * @buffer: buffer to load symlink location into
1224  * @buflen: length of buffer
1225  *
1226  */
1227
1228 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1229 {
1230         int retval;
1231
1232         struct v9fs_session_info *v9ses;
1233         struct p9_fid *fid;
1234         struct p9_wstat *st;
1235
1236         p9_debug(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1237         retval = -EPERM;
1238         v9ses = v9fs_dentry2v9ses(dentry);
1239         fid = v9fs_fid_lookup(dentry);
1240         if (IS_ERR(fid))
1241                 return PTR_ERR(fid);
1242
1243         if (!v9fs_proto_dotu(v9ses))
1244                 return -EBADF;
1245
1246         st = p9_client_stat(fid);
1247         if (IS_ERR(st))
1248                 return PTR_ERR(st);
1249
1250         if (!(st->mode & P9_DMSYMLINK)) {
1251                 retval = -EINVAL;
1252                 goto done;
1253         }
1254
1255         /* copy extension buffer into buffer */
1256         retval = min(strlen(st->extension)+1, (size_t)buflen);
1257         memcpy(buffer, st->extension, retval);
1258
1259         p9_debug(P9_DEBUG_VFS, "%s -> %s (%.*s)\n",
1260                  dentry->d_name.name, st->extension, buflen, buffer);
1261
1262 done:
1263         p9stat_free(st);
1264         kfree(st);
1265         return retval;
1266 }
1267
1268 /**
1269  * v9fs_vfs_follow_link - follow a symlink path
1270  * @dentry: dentry for symlink
1271  * @nd: nameidata
1272  *
1273  */
1274
1275 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1276 {
1277         int len = 0;
1278         char *link = __getname();
1279
1280         p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);
1281
1282         if (!link)
1283                 link = ERR_PTR(-ENOMEM);
1284         else {
1285                 len = v9fs_readlink(dentry, link, PATH_MAX);
1286
1287                 if (len < 0) {
1288                         __putname(link);
1289                         link = ERR_PTR(len);
1290                 } else
1291                         link[min(len, PATH_MAX-1)] = 0;
1292         }
1293         nd_set_link(nd, link);
1294
1295         return NULL;
1296 }
1297
1298 /**
1299  * v9fs_vfs_put_link - release a symlink path
1300  * @dentry: dentry for symlink
1301  * @nd: nameidata
1302  * @p: unused
1303  *
1304  */
1305
1306 void
1307 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1308 {
1309         char *s = nd_get_link(nd);
1310
1311         p9_debug(P9_DEBUG_VFS, " %s %s\n",
1312                  dentry->d_name.name, IS_ERR(s) ? "<error>" : s);
1313         if (!IS_ERR(s))
1314                 __putname(s);
1315 }
1316
1317 /**
1318  * v9fs_vfs_mkspecial - create a special file
1319  * @dir: inode to create special file in
1320  * @dentry: dentry to create
1321  * @mode: mode to create special file
1322  * @extension: 9p2000.u format extension string representing special file
1323  *
1324  */
1325
1326 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1327         u32 perm, const char *extension)
1328 {
1329         struct p9_fid *fid;
1330         struct v9fs_session_info *v9ses;
1331
1332         v9ses = v9fs_inode2v9ses(dir);
1333         if (!v9fs_proto_dotu(v9ses)) {
1334                 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1335                 return -EPERM;
1336         }
1337
1338         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1339                                                                 P9_OREAD);
1340         if (IS_ERR(fid))
1341                 return PTR_ERR(fid);
1342
1343         v9fs_invalidate_inode_attr(dir);
1344         p9_client_clunk(fid);
1345         return 0;
1346 }
1347
1348 /**
1349  * v9fs_vfs_symlink - helper function to create symlinks
1350  * @dir: directory inode containing symlink
1351  * @dentry: dentry for symlink
1352  * @symname: symlink data
1353  *
1354  * See Also: 9P2000.u RFC for more information
1355  *
1356  */
1357
1358 static int
1359 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1360 {
1361         p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1362                  dir->i_ino, dentry->d_name.name, symname);
1363
1364         return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname);
1365 }
1366
1367 /**
1368  * v9fs_vfs_link - create a hardlink
1369  * @old_dentry: dentry for file to link to
1370  * @dir: inode destination for new link
1371  * @dentry: dentry for link
1372  *
1373  */
1374
1375 static int
1376 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1377               struct dentry *dentry)
1378 {
1379         int retval;
1380         char *name;
1381         struct p9_fid *oldfid;
1382
1383         p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1384                  dir->i_ino, dentry->d_name.name, old_dentry->d_name.name);
1385
1386         oldfid = v9fs_fid_clone(old_dentry);
1387         if (IS_ERR(oldfid))
1388                 return PTR_ERR(oldfid);
1389
1390         name = __getname();
1391         if (unlikely(!name)) {
1392                 retval = -ENOMEM;
1393                 goto clunk_fid;
1394         }
1395
1396         sprintf(name, "%d\n", oldfid->fid);
1397         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1398         __putname(name);
1399         if (!retval) {
1400                 v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1401                 v9fs_invalidate_inode_attr(dir);
1402         }
1403 clunk_fid:
1404         p9_client_clunk(oldfid);
1405         return retval;
1406 }
1407
1408 /**
1409  * v9fs_vfs_mknod - create a special file
1410  * @dir: inode destination for new link
1411  * @dentry: dentry for file
1412  * @mode: mode for creation
1413  * @rdev: device associated with special file
1414  *
1415  */
1416
1417 static int
1418 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev)
1419 {
1420         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1421         int retval;
1422         char *name;
1423         u32 perm;
1424
1425         p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %hx MAJOR: %u MINOR: %u\n",
1426                  dir->i_ino, dentry->d_name.name, mode,
1427                  MAJOR(rdev), MINOR(rdev));
1428
1429         if (!new_valid_dev(rdev))
1430                 return -EINVAL;
1431
1432         name = __getname();
1433         if (!name)
1434                 return -ENOMEM;
1435         /* build extension */
1436         if (S_ISBLK(mode))
1437                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1438         else if (S_ISCHR(mode))
1439                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1440         else if (S_ISFIFO(mode))
1441                 *name = 0;
1442         else if (S_ISSOCK(mode))
1443                 *name = 0;
1444         else {
1445                 __putname(name);
1446                 return -EINVAL;
1447         }
1448
1449         perm = unixmode2p9mode(v9ses, mode);
1450         retval = v9fs_vfs_mkspecial(dir, dentry, perm, name);
1451         __putname(name);
1452
1453         return retval;
1454 }
1455
1456 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1457 {
1458         int umode;
1459         dev_t rdev;
1460         loff_t i_size;
1461         struct p9_wstat *st;
1462         struct v9fs_session_info *v9ses;
1463
1464         v9ses = v9fs_inode2v9ses(inode);
1465         st = p9_client_stat(fid);
1466         if (IS_ERR(st))
1467                 return PTR_ERR(st);
1468         /*
1469          * Don't update inode if the file type is different
1470          */
1471         umode = p9mode2unixmode(v9ses, st, &rdev);
1472         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1473                 goto out;
1474
1475         spin_lock(&inode->i_lock);
1476         /*
1477          * We don't want to refresh inode->i_size,
1478          * because we may have cached data
1479          */
1480         i_size = inode->i_size;
1481         v9fs_stat2inode(st, inode, inode->i_sb);
1482         if (v9ses->cache)
1483                 inode->i_size = i_size;
1484         spin_unlock(&inode->i_lock);
1485 out:
1486         p9stat_free(st);
1487         kfree(st);
1488         return 0;
1489 }
1490
1491 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1492         .create = v9fs_vfs_create,
1493         .lookup = v9fs_vfs_lookup,
1494         .atomic_open = v9fs_vfs_atomic_open,
1495         .symlink = v9fs_vfs_symlink,
1496         .link = v9fs_vfs_link,
1497         .unlink = v9fs_vfs_unlink,
1498         .mkdir = v9fs_vfs_mkdir,
1499         .rmdir = v9fs_vfs_rmdir,
1500         .mknod = v9fs_vfs_mknod,
1501         .rename = v9fs_vfs_rename,
1502         .getattr = v9fs_vfs_getattr,
1503         .setattr = v9fs_vfs_setattr,
1504 };
1505
1506 static const struct inode_operations v9fs_dir_inode_operations = {
1507         .create = v9fs_vfs_create,
1508         .lookup = v9fs_vfs_lookup,
1509         .atomic_open = v9fs_vfs_atomic_open,
1510         .unlink = v9fs_vfs_unlink,
1511         .mkdir = v9fs_vfs_mkdir,
1512         .rmdir = v9fs_vfs_rmdir,
1513         .mknod = v9fs_vfs_mknod,
1514         .rename = v9fs_vfs_rename,
1515         .getattr = v9fs_vfs_getattr,
1516         .setattr = v9fs_vfs_setattr,
1517 };
1518
1519 static const struct inode_operations v9fs_file_inode_operations = {
1520         .getattr = v9fs_vfs_getattr,
1521         .setattr = v9fs_vfs_setattr,
1522 };
1523
1524 static const struct inode_operations v9fs_symlink_inode_operations = {
1525         .readlink = generic_readlink,
1526         .follow_link = v9fs_vfs_follow_link,
1527         .put_link = v9fs_vfs_put_link,
1528         .getattr = v9fs_vfs_getattr,
1529         .setattr = v9fs_vfs_setattr,
1530 };
1531