fs/9p/vfs_inode.c

   1 /*
   2  *  linux/fs/9p/vfs_inode.c
   3  *
   4  * This file contains vfs inode ops for the 9P2000 protocol.
   5  *
   6  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/fs.h>
  29 #include <linux/file.h>
  30 #include <linux/pagemap.h>
  31 #include <linux/stat.h>
  32 #include <linux/string.h>
  33 #include <linux/inet.h>
  34 #include <linux/namei.h>
  35 #include <linux/idr.h>
  36 #include <linux/sched.h>
  37 #include <linux/slab.h>
  38 #include <linux/xattr.h>
  39 #include <linux/posix_acl.h>
  40 #include <net/9p/9p.h>
  41 #include <net/9p/client.h>
  42
  43 #include "v9fs.h"
  44 #include "v9fs_vfs.h"
  45 #include "fid.h"
  46 #include "cache.h"
  47 #include "xattr.h"
  48 #include "acl.h"
  49
  50 static const struct inode_operations v9fs_dir_inode_operations;
  51 static const struct inode_operations v9fs_dir_inode_operations_dotu;
  52 static const struct inode_operations v9fs_file_inode_operations;
  53 static const struct inode_operations v9fs_symlink_inode_operations;
  54
  55 /**
  56  * unixmode2p9mode - convert unix mode bits to plan 9
  57  * @v9ses: v9fs session information
  58  * @mode: mode to convert
  59  *
  60  */
  61
  62 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
  63 {
  64         int res;
  65         res = mode & 0777;
  66         if (S_ISDIR(mode))
  67                 res |= P9_DMDIR;
  68         if (v9fs_proto_dotu(v9ses)) {
  69                 if (S_ISLNK(mode))
  70                         res |= P9_DMSYMLINK;
  71                 if (v9ses->nodev == 0) {
  72                         if (S_ISSOCK(mode))
  73                                 res |= P9_DMSOCKET;
  74                         if (S_ISFIFO(mode))
  75                                 res |= P9_DMNAMEDPIPE;
  76                         if (S_ISBLK(mode))
  77                                 res |= P9_DMDEVICE;
  78                         if (S_ISCHR(mode))
  79                                 res |= P9_DMDEVICE;
  80                 }
  81
  82                 if ((mode & S_ISUID) == S_ISUID)
  83                         res |= P9_DMSETUID;
  84                 if ((mode & S_ISGID) == S_ISGID)
  85                         res |= P9_DMSETGID;
  86                 if ((mode & S_ISVTX) == S_ISVTX)
  87                         res |= P9_DMSETVTX;
  88                 if ((mode & P9_DMLINK))
  89                         res |= P9_DMLINK;
  90         }
  91
  92         return res;
  93 }
  94
  95 /**
  96  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  97  * @v9ses: v9fs session information
  98  * @mode: mode to convert
  99  *
 100  */
 101
 102 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
 103 {
 104         int res;
 105
 106         res = mode & 0777;
 107
 108         if ((mode & P9_DMDIR) == P9_DMDIR)
 109                 res |= S_IFDIR;
 110         else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 111                 res |= S_IFLNK;
 112         else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 113                  && (v9ses->nodev == 0))
 114                 res |= S_IFSOCK;
 115         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 116                  && (v9ses->nodev == 0))
 117                 res |= S_IFIFO;
 118         else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 119                  && (v9ses->nodev == 0))
 120                 res |= S_IFBLK;
 121         else
 122                 res |= S_IFREG;
 123
 124         if (v9fs_proto_dotu(v9ses)) {
 125                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
 126                         res |= S_ISUID;
 127
 128                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
 129                         res |= S_ISGID;
 130
 131                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 132                         res |= S_ISVTX;
 133         }
 134
 135         return res;
 136 }
 137
 138 /**
 139  * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 140  * @uflags: flags to convert
 141  * @extended: if .u extensions are active
 142  */
 143
 144 int v9fs_uflags2omode(int uflags, int extended)
 145 {
 146         int ret;
 147
 148         ret = 0;
 149         switch (uflags&3) {
 150         default:
 151         case O_RDONLY:
 152                 ret = P9_OREAD;
 153                 break;
 154
 155         case O_WRONLY:
 156                 ret = P9_OWRITE;
 157                 break;
 158
 159         case O_RDWR:
 160                 ret = P9_ORDWR;
 161                 break;
 162         }
 163
 164         if (uflags & O_TRUNC)
 165                 ret |= P9_OTRUNC;
 166
 167         if (extended) {
 168                 if (uflags & O_EXCL)
 169                         ret |= P9_OEXCL;
 170
 171                 if (uflags & O_APPEND)
 172                         ret |= P9_OAPPEND;
 173         }
 174
 175         return ret;
 176 }
 177
 178 /**
 179  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 180  * @wstat: structure to initialize
 181  *
 182  */
 183
 184 void
 185 v9fs_blank_wstat(struct p9_wstat *wstat)
 186 {
 187         wstat->type = ~0;
 188         wstat->dev = ~0;
 189         wstat->qid.type = ~0;
 190         wstat->qid.version = ~0;
 191         *((long long *)&wstat->qid.path) = ~0;
 192         wstat->mode = ~0;
 193         wstat->atime = ~0;
 194         wstat->mtime = ~0;
 195         wstat->length = ~0;
 196         wstat->name = NULL;
 197         wstat->uid = NULL;
 198         wstat->gid = NULL;
 199         wstat->muid = NULL;
 200         wstat->n_uid = ~0;
 201         wstat->n_gid = ~0;
 202         wstat->n_muid = ~0;
 203         wstat->extension = NULL;
 204 }
 205
 206 /**
 207  * v9fs_alloc_inode - helper function to allocate an inode
 208  *
 209  */
 210 struct inode *v9fs_alloc_inode(struct super_block *sb)
 211 {
 212         struct v9fs_inode *v9inode;
 213         v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 214                                                         GFP_KERNEL);
 215         if (!v9inode)
 216                 return NULL;
 217 #ifdef CONFIG_9P_FSCACHE
 218         v9inode->fscache = NULL;
 219         spin_lock_init(&v9inode->fscache_lock);
 220 #endif
 221         v9inode->writeback_fid = NULL;
 222         v9inode->cache_validity = 0;
 223         mutex_init(&v9inode->v_mutex);
 224         return &v9inode->vfs_inode;
 225 }
 226
 227 /**
 228  * v9fs_destroy_inode - destroy an inode
 229  *
 230  */
 231
 232 static void v9fs_i_callback(struct rcu_head *head)
 233 {
 234         struct inode *inode = container_of(head, struct inode, i_rcu);
 235         INIT_LIST_HEAD(&inode->i_dentry);
 236         kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 237 }
 238
 239 void v9fs_destroy_inode(struct inode *inode)
 240 {
 241         call_rcu(&inode->i_rcu, v9fs_i_callback);
 242 }
 243
 244 int v9fs_init_inode(struct v9fs_session_info *v9ses,
 245                     struct inode *inode, int mode)
 246 {
 247         int err = 0;
 248
 249         inode_init_owner(inode, NULL, mode);
 250         inode->i_blocks = 0;
 251         inode->i_rdev = 0;
 252         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 253         inode->i_mapping->a_ops = &v9fs_addr_operations;
 254
 255         switch (mode & S_IFMT) {
 256         case S_IFIFO:
 257         case S_IFBLK:
 258         case S_IFCHR:
 259         case S_IFSOCK:
 260                 if (v9fs_proto_dotl(v9ses)) {
 261                         inode->i_op = &v9fs_file_inode_operations_dotl;
 262                         inode->i_fop = &v9fs_file_operations_dotl;
 263                 } else if (v9fs_proto_dotu(v9ses)) {
 264                         inode->i_op = &v9fs_file_inode_operations;
 265                         inode->i_fop = &v9fs_file_operations;
 266                 } else {
 267                         P9_DPRINTK(P9_DEBUG_ERROR,
 268                                    "special files without extended mode\n");
 269                         err = -EINVAL;
 270                         goto error;
 271                 }
 272                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 273                 break;
 274         case S_IFREG:
 275                 if (v9fs_proto_dotl(v9ses)) {
 276                         inode->i_op = &v9fs_file_inode_operations_dotl;
 277                         if (v9ses->cache)
 278                                 inode->i_fop =
 279                                         &v9fs_cached_file_operations_dotl;
 280                         else
 281                                 inode->i_fop = &v9fs_file_operations_dotl;
 282                 } else {
 283                         inode->i_op = &v9fs_file_inode_operations;
 284                         if (v9ses->cache)
 285                                 inode->i_fop = &v9fs_cached_file_operations;
 286                         else
 287                                 inode->i_fop = &v9fs_file_operations;
 288                 }
 289
 290                 break;
 291         case S_IFLNK:
 292                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 293                         P9_DPRINTK(P9_DEBUG_ERROR, "extended modes used with "
 294                                                 "legacy protocol.\n");
 295                         err = -EINVAL;
 296                         goto error;
 297                 }
 298
 299                 if (v9fs_proto_dotl(v9ses))
 300                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
 301                 else
 302                         inode->i_op = &v9fs_symlink_inode_operations;
 303
 304                 break;
 305         case S_IFDIR:
 306                 inc_nlink(inode);
 307                 if (v9fs_proto_dotl(v9ses))
 308                         inode->i_op = &v9fs_dir_inode_operations_dotl;
 309                 else if (v9fs_proto_dotu(v9ses))
 310                         inode->i_op = &v9fs_dir_inode_operations_dotu;
 311                 else
 312                         inode->i_op = &v9fs_dir_inode_operations;
 313
 314                 if (v9fs_proto_dotl(v9ses))
 315                         inode->i_fop = &v9fs_dir_operations_dotl;
 316                 else
 317                         inode->i_fop = &v9fs_dir_operations;
 318
 319                 break;
 320         default:
 321                 P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
 322                            mode, mode & S_IFMT);
 323                 err = -EINVAL;
 324                 goto error;
 325         }
 326 error:
 327         return err;
 328
 329 }
 330
 331 /**
 332  * v9fs_get_inode - helper function to setup an inode
 333  * @sb: superblock
 334  * @mode: mode to setup inode with
 335  *
 336  */
 337
 338 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 339 {
 340         int err;
 341         struct inode *inode;
 342         struct v9fs_session_info *v9ses = sb->s_fs_info;
 343
 344         P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 345
 346         inode = new_inode(sb);
 347         if (!inode) {
 348                 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
 349                 return ERR_PTR(-ENOMEM);
 350         }
 351         err = v9fs_init_inode(v9ses, inode, mode);
 352         if (err) {
 353                 iput(inode);
 354                 return ERR_PTR(err);
 355         }
 356         return inode;
 357 }
 358
 359 /*
 360 static struct v9fs_fid*
 361 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 362 {
 363         int err;
 364         int nfid;
 365         struct v9fs_fid *ret;
 366         struct v9fs_fcall *fcall;
 367
 368         nfid = v9fs_get_idpool(&v9ses->fidpool);
 369         if (nfid < 0) {
 370                 eprintk(KERN_WARNING, "no free fids available\n");
 371                 return ERR_PTR(-ENOSPC);
 372         }
 373
 374         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 375                 &fcall);
 376
 377         if (err < 0) {
 378                 if (fcall && fcall->id == RWALK)
 379                         goto clunk_fid;
 380
 381                 PRINT_FCALL_ERROR("walk error", fcall);
 382                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 383                 goto error;
 384         }
 385
 386         kfree(fcall);
 387         fcall = NULL;
 388         ret = v9fs_fid_create(v9ses, nfid);
 389         if (!ret) {
 390                 err = -ENOMEM;
 391                 goto clunk_fid;
 392         }
 393
 394         err = v9fs_fid_insert(ret, dentry);
 395         if (err < 0) {
 396                 v9fs_fid_destroy(ret);
 397                 goto clunk_fid;
 398         }
 399
 400         return ret;
 401
 402 clunk_fid:
 403         v9fs_t_clunk(v9ses, nfid);
 404
 405 error:
 406         kfree(fcall);
 407         return ERR_PTR(err);
 408 }
 409 */
 410
 411
 412 /**
 413  * v9fs_clear_inode - release an inode
 414  * @inode: inode to release
 415  *
 416  */
 417 void v9fs_evict_inode(struct inode *inode)
 418 {
 419         struct v9fs_inode *v9inode = V9FS_I(inode);
 420
 421         truncate_inode_pages(inode->i_mapping, 0);
 422         end_writeback(inode);
 423         filemap_fdatawrite(inode->i_mapping);
 424
 425 #ifdef CONFIG_9P_FSCACHE
 426         v9fs_cache_inode_put_cookie(inode);
 427 #endif
 428         /* clunk the fid stashed in writeback_fid */
 429         if (v9inode->writeback_fid) {
 430                 p9_client_clunk(v9inode->writeback_fid);
 431                 v9inode->writeback_fid = NULL;
 432         }
 433 }
 434
 435 static int v9fs_test_inode(struct inode *inode, void *data)
 436 {
 437         int umode;
 438         struct v9fs_inode *v9inode = V9FS_I(inode);
 439         struct p9_wstat *st = (struct p9_wstat *)data;
 440         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 441
 442         umode = p9mode2unixmode(v9ses, st->mode);
 443         /* don't match inode of different type */
 444         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 445                 return 0;
 446
 447         /* compare qid details */
 448         if (memcmp(&v9inode->qid.version,
 449                    &st->qid.version, sizeof(v9inode->qid.version)))
 450                 return 0;
 451
 452         if (v9inode->qid.type != st->qid.type)
 453                 return 0;
 454         return 1;
 455 }
 456
 457 static int v9fs_test_new_inode(struct inode *inode, void *data)
 458 {
 459         return 0;
 460 }
 461
 462 static int v9fs_set_inode(struct inode *inode,  void *data)
 463 {
 464         struct v9fs_inode *v9inode = V9FS_I(inode);
 465         struct p9_wstat *st = (struct p9_wstat *)data;
 466
 467         memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 468         return 0;
 469 }
 470
 471 static struct inode *v9fs_qid_iget(struct super_block *sb,
 472                                    struct p9_qid *qid,
 473                                    struct p9_wstat *st,
 474                                    int new)
 475 {
 476         int retval, umode;
 477         unsigned long i_ino;
 478         struct inode *inode;
 479         struct v9fs_session_info *v9ses = sb->s_fs_info;
 480         int (*test)(struct inode *, void *);
 481
 482         if (new)
 483                 test = v9fs_test_new_inode;
 484         else
 485                 test = v9fs_test_inode;
 486
 487         i_ino = v9fs_qid2ino(qid);
 488         inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 489         if (!inode)
 490                 return ERR_PTR(-ENOMEM);
 491         if (!(inode->i_state & I_NEW))
 492                 return inode;
 493         /*
 494          * initialize the inode with the stat info
 495          * FIXME!! we may need support for stale inodes
 496          * later.
 497          */
 498         inode->i_ino = i_ino;
 499         umode = p9mode2unixmode(v9ses, st->mode);
 500         retval = v9fs_init_inode(v9ses, inode, umode);
 501         if (retval)
 502                 goto error;
 503
 504         v9fs_stat2inode(st, inode, sb);
 505 #ifdef CONFIG_9P_FSCACHE
 506         v9fs_cache_inode_get_cookie(inode);
 507 #endif
 508         unlock_new_inode(inode);
 509         return inode;
 510 error:
 511         unlock_new_inode(inode);
 512         iput(inode);
 513         return ERR_PTR(retval);
 514
 515 }
 516
 517 struct inode *
 518 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 519                     struct super_block *sb, int new)
 520 {
 521         struct p9_wstat *st;
 522         struct inode *inode = NULL;
 523
 524         st = p9_client_stat(fid);
 525         if (IS_ERR(st))
 526                 return ERR_CAST(st);
 527
 528         inode = v9fs_qid_iget(sb, &st->qid, st, new);
 529         p9stat_free(st);
 530         kfree(st);
 531         return inode;
 532 }
 533
 534 /**
 535  * v9fs_remove - helper function to remove files and directories
 536  * @dir: directory inode that is being deleted
 537  * @dentry:  dentry that is being deleted
 538  * @rmdir: removing a directory
 539  *
 540  */
 541
 542 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 543 {
 544         struct inode *inode;
 545         int retval = -EOPNOTSUPP;
 546         struct p9_fid *v9fid, *dfid;
 547         struct v9fs_session_info *v9ses;
 548
 549         P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 550                    dir, dentry, flags);
 551
 552         v9ses = v9fs_inode2v9ses(dir);
 553         inode = dentry->d_inode;
 554         dfid = v9fs_fid_lookup(dentry->d_parent);
 555         if (IS_ERR(dfid)) {
 556                 retval = PTR_ERR(dfid);
 557                 P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 558                 return retval;
 559         }
 560         if (v9fs_proto_dotl(v9ses))
 561                 retval = p9_client_unlinkat(dfid, dentry->d_name.name, flags);
 562         if (retval == -EOPNOTSUPP) {
 563                 /* Try the one based on path */
 564                 v9fid = v9fs_fid_clone(dentry);
 565                 if (IS_ERR(v9fid))
 566                         return PTR_ERR(v9fid);
 567                 retval = p9_client_remove(v9fid);
 568         }
 569         if (!retval) {
 570                 /*
 571                  * directories on unlink should have zero
 572                  * link count
 573                  */
 574                 if (flags & AT_REMOVEDIR) {
 575                         clear_nlink(inode);
 576                         drop_nlink(dir);
 577                 } else
 578                         drop_nlink(inode);
 579
 580                 v9fs_invalidate_inode_attr(inode);
 581                 v9fs_invalidate_inode_attr(dir);
 582         }
 583         return retval;
 584 }
 585
 586 /**
 587  * v9fs_create - Create a file
 588  * @v9ses: session information
 589  * @dir: directory that dentry is being created in
 590  * @dentry:  dentry that is being created
 591  * @extension: 9p2000.u extension string to support devices, etc.
 592  * @perm: create permissions
 593  * @mode: open mode
 594  *
 595  */
 596 static struct p9_fid *
 597 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 598                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 599 {
 600         int err;
 601         char *name;
 602         struct p9_fid *dfid, *ofid, *fid;
 603         struct inode *inode;
 604
 605         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 606
 607         err = 0;
 608         ofid = NULL;
 609         fid = NULL;
 610         name = (char *) dentry->d_name.name;
 611         dfid = v9fs_fid_lookup(dentry->d_parent);
 612         if (IS_ERR(dfid)) {
 613                 err = PTR_ERR(dfid);
 614                 P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 615                 return ERR_PTR(err);
 616         }
 617
 618         /* clone a fid to use for creation */
 619         ofid = p9_client_walk(dfid, 0, NULL, 1);
 620         if (IS_ERR(ofid)) {
 621                 err = PTR_ERR(ofid);
 622                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 623                 return ERR_PTR(err);
 624         }
 625
 626         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 627         if (err < 0) {
 628                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 629                 goto error;
 630         }
 631
 632         /* now walk from the parent so we can get unopened fid */
 633         fid = p9_client_walk(dfid, 1, &name, 1);
 634         if (IS_ERR(fid)) {
 635                 err = PTR_ERR(fid);
 636                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 637                 fid = NULL;
 638                 goto error;
 639         }
 640
 641         /* instantiate inode and assign the unopened fid to the dentry */
 642         inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 643         if (IS_ERR(inode)) {
 644                 err = PTR_ERR(inode);
 645                 P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
 646                 goto error;
 647         }
 648         d_instantiate(dentry, inode);
 649         err = v9fs_fid_add(dentry, fid);
 650         if (err < 0)
 651                 goto error;
 652
 653         return ofid;
 654
 655 error:
 656         if (ofid)
 657                 p9_client_clunk(ofid);
 658
 659         if (fid)
 660                 p9_client_clunk(fid);
 661
 662         return ERR_PTR(err);
 663 }
 664
 665 /**
 666  * v9fs_vfs_create - VFS hook to create files
 667  * @dir: directory inode that is being created
 668  * @dentry:  dentry that is being deleted
 669  * @mode: create permissions
 670  * @nd: path information
 671  *
 672  */
 673
 674 static int
 675 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 676                 struct nameidata *nd)
 677 {
 678         int err;
 679         u32 perm;
 680         int flags;
 681         struct file *filp;
 682         struct v9fs_inode *v9inode;
 683         struct v9fs_session_info *v9ses;
 684         struct p9_fid *fid, *inode_fid;
 685
 686         err = 0;
 687         fid = NULL;
 688         v9ses = v9fs_inode2v9ses(dir);
 689         perm = unixmode2p9mode(v9ses, mode);
 690         if (nd)
 691                 flags = nd->intent.open.flags;
 692         else
 693                 flags = O_RDWR;
 694
 695         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 696                                 v9fs_uflags2omode(flags,
 697                                                 v9fs_proto_dotu(v9ses)));
 698         if (IS_ERR(fid)) {
 699                 err = PTR_ERR(fid);
 700                 fid = NULL;
 701                 goto error;
 702         }
 703
 704         v9fs_invalidate_inode_attr(dir);
 705         /* if we are opening a file, assign the open fid to the file */
 706         if (nd) {
 707                 v9inode = V9FS_I(dentry->d_inode);
 708                 mutex_lock(&v9inode->v_mutex);
 709                 if (v9ses->cache && !v9inode->writeback_fid &&
 710                     ((flags & O_ACCMODE) != O_RDONLY)) {
 711                         /*
 712                          * clone a fid and add it to writeback_fid
 713                          * we do it during open time instead of
 714                          * page dirty time via write_begin/page_mkwrite
 715                          * because we want write after unlink usecase
 716                          * to work.
 717                          */
 718                         inode_fid = v9fs_writeback_fid(dentry);
 719                         if (IS_ERR(inode_fid)) {
 720                                 err = PTR_ERR(inode_fid);
 721                                 mutex_unlock(&v9inode->v_mutex);
 722                                 goto error;
 723                         }
 724                         v9inode->writeback_fid = (void *) inode_fid;
 725                 }
 726                 mutex_unlock(&v9inode->v_mutex);
 727                 filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
 728                 if (IS_ERR(filp)) {
 729                         err = PTR_ERR(filp);
 730                         goto error;
 731                 }
 732
 733                 filp->private_data = fid;
 734 #ifdef CONFIG_9P_FSCACHE
 735                 if (v9ses->cache)
 736                         v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
 737 #endif
 738         } else
 739                 p9_client_clunk(fid);
 740
 741         return 0;
 742
 743 error:
 744         if (fid)
 745                 p9_client_clunk(fid);
 746
 747         return err;
 748 }
 749
 750 /**
 751  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 752  * @dir:  inode that is being unlinked
 753  * @dentry: dentry that is being unlinked
 754  * @mode: mode for new directory
 755  *
 756  */
 757
 758 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 759 {
 760         int err;
 761         u32 perm;
 762         struct p9_fid *fid;
 763         struct v9fs_session_info *v9ses;
 764
 765         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 766         err = 0;
 767         v9ses = v9fs_inode2v9ses(dir);
 768         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 769         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 770         if (IS_ERR(fid)) {
 771                 err = PTR_ERR(fid);
 772                 fid = NULL;
 773         } else {
 774                 inc_nlink(dir);
 775                 v9fs_invalidate_inode_attr(dir);
 776         }
 777
 778         if (fid)
 779                 p9_client_clunk(fid);
 780
 781         return err;
 782 }
 783
 784 /**
 785  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 786  * @dir:  inode that is being walked from
 787  * @dentry: dentry that is being walked to?
 788  * @nameidata: path data
 789  *
 790  */
 791
 792 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 793                                       struct nameidata *nameidata)
 794 {
 795         struct super_block *sb;
 796         struct v9fs_session_info *v9ses;
 797         struct p9_fid *dfid, *fid;
 798         struct inode *inode;
 799         char *name;
 800         int result = 0;
 801
 802         P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 803                 dir, dentry->d_name.name, dentry, nameidata);
 804
 805         if (dentry->d_name.len > NAME_MAX)
 806                 return ERR_PTR(-ENAMETOOLONG);
 807
 808         sb = dir->i_sb;
 809         v9ses = v9fs_inode2v9ses(dir);
 810         /* We can walk d_parent because we hold the dir->i_mutex */
 811         dfid = v9fs_fid_lookup(dentry->d_parent);
 812         if (IS_ERR(dfid))
 813                 return ERR_CAST(dfid);
 814
 815         name = (char *) dentry->d_name.name;
 816         fid = p9_client_walk(dfid, 1, &name, 1);
 817         if (IS_ERR(fid)) {
 818                 result = PTR_ERR(fid);
 819                 if (result == -ENOENT) {
 820                         inode = NULL;
 821                         goto inst_out;
 822                 }
 823
 824                 return ERR_PTR(result);
 825         }
 826
 827         inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 828         if (IS_ERR(inode)) {
 829                 result = PTR_ERR(inode);
 830                 inode = NULL;
 831                 goto error;
 832         }
 833
 834         result = v9fs_fid_add(dentry, fid);
 835         if (result < 0)
 836                 goto error_iput;
 837
 838 inst_out:
 839         d_add(dentry, inode);
 840         return NULL;
 841
 842 error_iput:
 843         iput(inode);
 844 error:
 845         p9_client_clunk(fid);
 846
 847         return ERR_PTR(result);
 848 }
 849
 850 /**
 851  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 852  * @i:  inode that is being unlinked
 853  * @d: dentry that is being unlinked
 854  *
 855  */
 856
 857 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 858 {
 859         return v9fs_remove(i, d, 0);
 860 }
 861
 862 /**
 863  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 864  * @i:  inode that is being unlinked
 865  * @d: dentry that is being unlinked
 866  *
 867  */
 868
 869 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 870 {
 871         return v9fs_remove(i, d, AT_REMOVEDIR);
 872 }
 873
 874 /**
 875  * v9fs_vfs_rename - VFS hook to rename an inode
 876  * @old_dir:  old dir inode
 877  * @old_dentry: old dentry
 878  * @new_dir: new dir inode
 879  * @new_dentry: new dentry
 880  *
 881  */
 882
 883 int
 884 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 885                 struct inode *new_dir, struct dentry *new_dentry)
 886 {
 887         int retval;
 888         struct inode *old_inode;
 889         struct inode *new_inode;
 890         struct v9fs_session_info *v9ses;
 891         struct p9_fid *oldfid;
 892         struct p9_fid *olddirfid;
 893         struct p9_fid *newdirfid;
 894         struct p9_wstat wstat;
 895
 896         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 897         retval = 0;
 898         old_inode = old_dentry->d_inode;
 899         new_inode = new_dentry->d_inode;
 900         v9ses = v9fs_inode2v9ses(old_inode);
 901         oldfid = v9fs_fid_lookup(old_dentry);
 902         if (IS_ERR(oldfid))
 903                 return PTR_ERR(oldfid);
 904
 905         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 906         if (IS_ERR(olddirfid)) {
 907                 retval = PTR_ERR(olddirfid);
 908                 goto done;
 909         }
 910
 911         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 912         if (IS_ERR(newdirfid)) {
 913                 retval = PTR_ERR(newdirfid);
 914                 goto clunk_olddir;
 915         }
 916
 917         down_write(&v9ses->rename_sem);
 918         if (v9fs_proto_dotl(v9ses)) {
 919                 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 920                                             newdirfid, new_dentry->d_name.name);
 921                 if (retval == -EOPNOTSUPP)
 922                         retval = p9_client_rename(oldfid, newdirfid,
 923                                                   new_dentry->d_name.name);
 924                 if (retval != -EOPNOTSUPP)
 925                         goto clunk_newdir;
 926         }
 927         if (old_dentry->d_parent != new_dentry->d_parent) {
 928                 /*
 929                  * 9P .u can only handle file rename in the same directory
 930                  */
 931
 932                 P9_DPRINTK(P9_DEBUG_ERROR,
 933                                 "old dir and new dir are different\n");
 934                 retval = -EXDEV;
 935                 goto clunk_newdir;
 936         }
 937         v9fs_blank_wstat(&wstat);
 938         wstat.muid = v9ses->uname;
 939         wstat.name = (char *) new_dentry->d_name.name;
 940         retval = p9_client_wstat(oldfid, &wstat);
 941
 942 clunk_newdir:
 943         if (!retval) {
 944                 if (new_inode) {
 945                         if (S_ISDIR(new_inode->i_mode))
 946                                 clear_nlink(new_inode);
 947                         else
 948                                 drop_nlink(new_inode);
 949                 }
 950                 if (S_ISDIR(old_inode->i_mode)) {
 951                         if (!new_inode)
 952                                 inc_nlink(new_dir);
 953                         drop_nlink(old_dir);
 954                 }
 955                 v9fs_invalidate_inode_attr(old_inode);
 956                 v9fs_invalidate_inode_attr(old_dir);
 957                 v9fs_invalidate_inode_attr(new_dir);
 958
 959                 /* successful rename */
 960                 d_move(old_dentry, new_dentry);
 961         }
 962         up_write(&v9ses->rename_sem);
 963         p9_client_clunk(newdirfid);
 964
 965 clunk_olddir:
 966         p9_client_clunk(olddirfid);
 967
 968 done:
 969         return retval;
 970 }
 971
 972 /**
 973  * v9fs_vfs_getattr - retrieve file metadata
 974  * @mnt: mount information
 975  * @dentry: file to get attributes on
 976  * @stat: metadata structure to populate
 977  *
 978  */
 979
 980 static int
 981 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 982                  struct kstat *stat)
 983 {
 984         int err;
 985         struct v9fs_session_info *v9ses;
 986         struct p9_fid *fid;
 987         struct p9_wstat *st;
 988
 989         P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 990         err = -EPERM;
 991         v9ses = v9fs_dentry2v9ses(dentry);
 992         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
 993                 generic_fillattr(dentry->d_inode, stat);
 994                 return 0;
 995         }
 996         fid = v9fs_fid_lookup(dentry);
 997         if (IS_ERR(fid))
 998                 return PTR_ERR(fid);
 999
1000         st = p9_client_stat(fid);
1001         if (IS_ERR(st))
1002                 return PTR_ERR(st);
1003
1004         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1005                 generic_fillattr(dentry->d_inode, stat);
1006
1007         p9stat_free(st);
1008         kfree(st);
1009         return 0;
1010 }
1011
1012 /**
1013  * v9fs_vfs_setattr - set file metadata
1014  * @dentry: file whose metadata to set
1015  * @iattr: metadata assignment structure
1016  *
1017  */
1018
1019 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1020 {
1021         int retval;
1022         struct v9fs_session_info *v9ses;
1023         struct p9_fid *fid;
1024         struct p9_wstat wstat;
1025
1026         P9_DPRINTK(P9_DEBUG_VFS, "\n");
1027         retval = inode_change_ok(dentry->d_inode, iattr);
1028         if (retval)
1029                 return retval;
1030
1031         retval = -EPERM;
1032         v9ses = v9fs_dentry2v9ses(dentry);
1033         fid = v9fs_fid_lookup(dentry);
1034         if(IS_ERR(fid))
1035                 return PTR_ERR(fid);
1036
1037         v9fs_blank_wstat(&wstat);
1038         if (iattr->ia_valid & ATTR_MODE)
1039                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1040
1041         if (iattr->ia_valid & ATTR_MTIME)
1042                 wstat.mtime = iattr->ia_mtime.tv_sec;
1043
1044         if (iattr->ia_valid & ATTR_ATIME)
1045                 wstat.atime = iattr->ia_atime.tv_sec;
1046
1047         if (iattr->ia_valid & ATTR_SIZE)
1048                 wstat.length = iattr->ia_size;
1049
1050         if (v9fs_proto_dotu(v9ses)) {
1051                 if (iattr->ia_valid & ATTR_UID)
1052                         wstat.n_uid = iattr->ia_uid;
1053
1054                 if (iattr->ia_valid & ATTR_GID)
1055                         wstat.n_gid = iattr->ia_gid;
1056         }
1057
1058         /* Write all dirty data */
1059         if (S_ISREG(dentry->d_inode->i_mode))
1060                 filemap_write_and_wait(dentry->d_inode->i_mapping);
1061
1062         retval = p9_client_wstat(fid, &wstat);
1063         if (retval < 0)
1064                 return retval;
1065
1066         if ((iattr->ia_valid & ATTR_SIZE) &&
1067             iattr->ia_size != i_size_read(dentry->d_inode))
1068                 truncate_setsize(dentry->d_inode, iattr->ia_size);
1069
1070         v9fs_invalidate_inode_attr(dentry->d_inode);
1071
1072         setattr_copy(dentry->d_inode, iattr);
1073         mark_inode_dirty(dentry->d_inode);
1074         return 0;
1075 }
1076
1077 /**
1078  * v9fs_stat2inode - populate an inode structure with mistat info
1079  * @stat: Plan 9 metadata (mistat) structure
1080  * @inode: inode to populate
1081  * @sb: superblock of filesystem
1082  *
1083  */
1084
1085 void
1086 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1087         struct super_block *sb)
1088 {
1089         char ext[32];
1090         char tag_name[14];
1091         unsigned int i_nlink;
1092         struct v9fs_session_info *v9ses = sb->s_fs_info;
1093         struct v9fs_inode *v9inode = V9FS_I(inode);
1094
1095         inode->i_nlink = 1;
1096
1097         inode->i_atime.tv_sec = stat->atime;
1098         inode->i_mtime.tv_sec = stat->mtime;
1099         inode->i_ctime.tv_sec = stat->mtime;
1100
1101         inode->i_uid = v9ses->dfltuid;
1102         inode->i_gid = v9ses->dfltgid;
1103
1104         if (v9fs_proto_dotu(v9ses)) {
1105                 inode->i_uid = stat->n_uid;
1106                 inode->i_gid = stat->n_gid;
1107         }
1108         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1109                 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1110                         /*
1111                          * Hadlink support got added later to
1112                          * to the .u extension. So there can be
1113                          * server out there that doesn't support
1114                          * this even with .u extension. So check
1115                          * for non NULL stat->extension
1116                          */
1117                         strncpy(ext, stat->extension, sizeof(ext));
1118                         /* HARDLINKCOUNT %u */
1119                         sscanf(ext, "%13s %u", tag_name, &i_nlink);
1120                         if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1121                                 inode->i_nlink = i_nlink;
1122                 }
1123         }
1124         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
1125         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
1126                 char type = 0;
1127                 int major = -1;
1128                 int minor = -1;
1129
1130                 strncpy(ext, stat->extension, sizeof(ext));
1131                 sscanf(ext, "%c %u %u", &type, &major, &minor);
1132                 switch (type) {
1133                 case 'c':
1134                         inode->i_mode &= ~S_IFBLK;
1135                         inode->i_mode |= S_IFCHR;
1136                         break;
1137                 case 'b':
1138                         break;
1139                 default:
1140                         P9_DPRINTK(P9_DEBUG_ERROR,
1141                                 "Unknown special type %c %s\n", type,
1142                                 stat->extension);
1143                 };
1144                 inode->i_rdev = MKDEV(major, minor);
1145                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
1146         } else
1147                 inode->i_rdev = 0;
1148
1149         i_size_write(inode, stat->length);
1150
1151         /* not real number of blocks, but 512 byte ones ... */
1152         inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1153         v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1154 }
1155
1156 /**
1157  * v9fs_qid2ino - convert qid into inode number
1158  * @qid: qid to hash
1159  *
1160  * BUG: potential for inode number collisions?
1161  */
1162
1163 ino_t v9fs_qid2ino(struct p9_qid *qid)
1164 {
1165         u64 path = qid->path + 2;
1166         ino_t i = 0;
1167
1168         if (sizeof(ino_t) == sizeof(path))
1169                 memcpy(&i, &path, sizeof(ino_t));
1170         else
1171                 i = (ino_t) (path ^ (path >> 32));
1172
1173         return i;
1174 }
1175
1176 /**
1177  * v9fs_readlink - read a symlink's location (internal version)
1178  * @dentry: dentry for symlink
1179  * @buffer: buffer to load symlink location into
1180  * @buflen: length of buffer
1181  *
1182  */
1183
1184 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1185 {
1186         int retval;
1187
1188         struct v9fs_session_info *v9ses;
1189         struct p9_fid *fid;
1190         struct p9_wstat *st;
1191
1192         P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1193         retval = -EPERM;
1194         v9ses = v9fs_dentry2v9ses(dentry);
1195         fid = v9fs_fid_lookup(dentry);
1196         if (IS_ERR(fid))
1197                 return PTR_ERR(fid);
1198
1199         if (!v9fs_proto_dotu(v9ses))
1200                 return -EBADF;
1201
1202         st = p9_client_stat(fid);
1203         if (IS_ERR(st))
1204                 return PTR_ERR(st);
1205
1206         if (!(st->mode & P9_DMSYMLINK)) {
1207                 retval = -EINVAL;
1208                 goto done;
1209         }
1210
1211         /* copy extension buffer into buffer */
1212         strncpy(buffer, st->extension, buflen);
1213
1214         P9_DPRINTK(P9_DEBUG_VFS,
1215                 "%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
1216
1217         retval = strnlen(buffer, buflen);
1218 done:
1219         p9stat_free(st);
1220         kfree(st);
1221         return retval;
1222 }
1223
1224 /**
1225  * v9fs_vfs_follow_link - follow a symlink path
1226  * @dentry: dentry for symlink
1227  * @nd: nameidata
1228  *
1229  */
1230
1231 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1232 {
1233         int len = 0;
1234         char *link = __getname();
1235
1236         P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
1237
1238         if (!link)
1239                 link = ERR_PTR(-ENOMEM);
1240         else {
1241                 len = v9fs_readlink(dentry, link, PATH_MAX);
1242
1243                 if (len < 0) {
1244                         __putname(link);
1245                         link = ERR_PTR(len);
1246                 } else
1247                         link[min(len, PATH_MAX-1)] = 0;
1248         }
1249         nd_set_link(nd, link);
1250
1251         return NULL;
1252 }
1253
1254 /**
1255  * v9fs_vfs_put_link - release a symlink path
1256  * @dentry: dentry for symlink
1257  * @nd: nameidata
1258  * @p: unused
1259  *
1260  */
1261
1262 void
1263 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1264 {
1265         char *s = nd_get_link(nd);
1266
1267         P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
1268                 IS_ERR(s) ? "<error>" : s);
1269         if (!IS_ERR(s))
1270                 __putname(s);
1271 }
1272
1273 /**
1274  * v9fs_vfs_mkspecial - create a special file
1275  * @dir: inode to create special file in
1276  * @dentry: dentry to create
1277  * @mode: mode to create special file
1278  * @extension: 9p2000.u format extension string representing special file
1279  *
1280  */
1281
1282 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1283         int mode, const char *extension)
1284 {
1285         u32 perm;
1286         struct p9_fid *fid;
1287         struct v9fs_session_info *v9ses;
1288
1289         v9ses = v9fs_inode2v9ses(dir);
1290         if (!v9fs_proto_dotu(v9ses)) {
1291                 P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1292                 return -EPERM;
1293         }
1294
1295         perm = unixmode2p9mode(v9ses, mode);
1296         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1297                                                                 P9_OREAD);
1298         if (IS_ERR(fid))
1299                 return PTR_ERR(fid);
1300
1301         v9fs_invalidate_inode_attr(dir);
1302         p9_client_clunk(fid);
1303         return 0;
1304 }
1305
1306 /**
1307  * v9fs_vfs_symlink - helper function to create symlinks
1308  * @dir: directory inode containing symlink
1309  * @dentry: dentry for symlink
1310  * @symname: symlink data
1311  *
1312  * See Also: 9P2000.u RFC for more information
1313  *
1314  */
1315
1316 static int
1317 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1318 {
1319         P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1320                                         dentry->d_name.name, symname);
1321
1322         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1323 }
1324
1325 /**
1326  * v9fs_vfs_link - create a hardlink
1327  * @old_dentry: dentry for file to link to
1328  * @dir: inode destination for new link
1329  * @dentry: dentry for link
1330  *
1331  */
1332
1333 static int
1334 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1335               struct dentry *dentry)
1336 {
1337         int retval;
1338         char *name;
1339         struct p9_fid *oldfid;
1340
1341         P9_DPRINTK(P9_DEBUG_VFS,
1342                 " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1343                 old_dentry->d_name.name);
1344
1345         oldfid = v9fs_fid_clone(old_dentry);
1346         if (IS_ERR(oldfid))
1347                 return PTR_ERR(oldfid);
1348
1349         name = __getname();
1350         if (unlikely(!name)) {
1351                 retval = -ENOMEM;
1352                 goto clunk_fid;
1353         }
1354
1355         sprintf(name, "%d\n", oldfid->fid);
1356         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1357         __putname(name);
1358         if (!retval) {
1359                 v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1360                 v9fs_invalidate_inode_attr(dir);
1361         }
1362 clunk_fid:
1363         p9_client_clunk(oldfid);
1364         return retval;
1365 }
1366
1367 /**
1368  * v9fs_vfs_mknod - create a special file
1369  * @dir: inode destination for new link
1370  * @dentry: dentry for file
1371  * @mode: mode for creation
1372  * @rdev: device associated with special file
1373  *
1374  */
1375
1376 static int
1377 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1378 {
1379         int retval;
1380         char *name;
1381
1382         P9_DPRINTK(P9_DEBUG_VFS,
1383                 " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1384                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1385
1386         if (!new_valid_dev(rdev))
1387                 return -EINVAL;
1388
1389         name = __getname();
1390         if (!name)
1391                 return -ENOMEM;
1392         /* build extension */
1393         if (S_ISBLK(mode))
1394                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1395         else if (S_ISCHR(mode))
1396                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1397         else if (S_ISFIFO(mode))
1398                 *name = 0;
1399         else if (S_ISSOCK(mode))
1400                 *name = 0;
1401         else {
1402                 __putname(name);
1403                 return -EINVAL;
1404         }
1405
1406         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1407         __putname(name);
1408
1409         return retval;
1410 }
1411
1412 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1413 {
1414         loff_t i_size;
1415         struct p9_wstat *st;
1416         struct v9fs_session_info *v9ses;
1417
1418         v9ses = v9fs_inode2v9ses(inode);
1419         st = p9_client_stat(fid);
1420         if (IS_ERR(st))
1421                 return PTR_ERR(st);
1422
1423         spin_lock(&inode->i_lock);
1424         /*
1425          * We don't want to refresh inode->i_size,
1426          * because we may have cached data
1427          */
1428         i_size = inode->i_size;
1429         v9fs_stat2inode(st, inode, inode->i_sb);
1430         if (v9ses->cache)
1431                 inode->i_size = i_size;
1432         spin_unlock(&inode->i_lock);
1433         p9stat_free(st);
1434         kfree(st);
1435         return 0;
1436 }
1437
1438 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1439         .create = v9fs_vfs_create,
1440         .lookup = v9fs_vfs_lookup,
1441         .symlink = v9fs_vfs_symlink,
1442         .link = v9fs_vfs_link,
1443         .unlink = v9fs_vfs_unlink,
1444         .mkdir = v9fs_vfs_mkdir,
1445         .rmdir = v9fs_vfs_rmdir,
1446         .mknod = v9fs_vfs_mknod,
1447         .rename = v9fs_vfs_rename,
1448         .getattr = v9fs_vfs_getattr,
1449         .setattr = v9fs_vfs_setattr,
1450 };
1451
1452 static const struct inode_operations v9fs_dir_inode_operations = {
1453         .create = v9fs_vfs_create,
1454         .lookup = v9fs_vfs_lookup,
1455         .unlink = v9fs_vfs_unlink,
1456         .mkdir = v9fs_vfs_mkdir,
1457         .rmdir = v9fs_vfs_rmdir,
1458         .mknod = v9fs_vfs_mknod,
1459         .rename = v9fs_vfs_rename,
1460         .getattr = v9fs_vfs_getattr,
1461         .setattr = v9fs_vfs_setattr,
1462 };
1463
1464 static const struct inode_operations v9fs_file_inode_operations = {
1465         .getattr = v9fs_vfs_getattr,
1466         .setattr = v9fs_vfs_setattr,
1467 };
1468
1469 static const struct inode_operations v9fs_symlink_inode_operations = {
1470         .readlink = generic_readlink,
1471         .follow_link = v9fs_vfs_follow_link,
1472         .put_link = v9fs_vfs_put_link,
1473         .getattr = v9fs_vfs_getattr,
1474         .setattr = v9fs_vfs_setattr,
1475 };
1476