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