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 int unixmode2p9mode(struct v9fs_session_info *v9ses, int 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 (S_ISLNK(mode))
  72                         res |= P9_DMSYMLINK;
  73                 if (v9ses->nodev == 0) {
  74                         if (S_ISSOCK(mode))
  75                                 res |= P9_DMSOCKET;
  76                         if (S_ISFIFO(mode))
  77                                 res |= P9_DMNAMEDPIPE;
  78                         if (S_ISBLK(mode))
  79                                 res |= P9_DMDEVICE;
  80                         if (S_ISCHR(mode))
  81                                 res |= P9_DMDEVICE;
  82                 }
  83
  84                 if ((mode & S_ISUID) == S_ISUID)
  85                         res |= P9_DMSETUID;
  86                 if ((mode & S_ISGID) == S_ISGID)
  87                         res |= P9_DMSETGID;
  88                 if ((mode & S_ISVTX) == S_ISVTX)
  89                         res |= P9_DMSETVTX;
  90                 if ((mode & P9_DMLINK))
  91                         res |= P9_DMLINK;
  92         }
  93
  94         return res;
  95 }
  96
  97 /**
  98  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  99  * @v9ses: v9fs session information
 100  * @stat: p9_wstat from which mode need to be derived
 101  * @rdev: major number, minor number in case of device files.
 102  *
 103  */
 104 static int p9mode2unixmode(struct v9fs_session_info *v9ses,
 105                            struct p9_wstat *stat, dev_t *rdev)
 106 {
 107         int res;
 108         int mode = stat->mode;
 109
 110         res = mode & S_IALLUGO;
 111         *rdev = 0;
 112
 113         if ((mode & P9_DMDIR) == P9_DMDIR)
 114                 res |= S_IFDIR;
 115         else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses)))
 116                 res |= S_IFLNK;
 117         else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses))
 118                  && (v9ses->nodev == 0))
 119                 res |= S_IFSOCK;
 120         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses))
 121                  && (v9ses->nodev == 0))
 122                 res |= S_IFIFO;
 123         else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses))
 124                  && (v9ses->nodev == 0)) {
 125                 char type = 0, ext[32];
 126                 int major = -1, minor = -1;
 127
 128                 strncpy(ext, stat->extension, sizeof(ext));
 129                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 130                 switch (type) {
 131                 case 'c':
 132                         res |= S_IFCHR;
 133                         break;
 134                 case 'b':
 135                         res |= S_IFBLK;
 136                         break;
 137                 default:
 138                         p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n",
 139                                  type, stat->extension);
 140                 };
 141                 *rdev = MKDEV(major, minor);
 142         } else
 143                 res |= S_IFREG;
 144
 145         if (v9fs_proto_dotu(v9ses)) {
 146                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
 147                         res |= S_ISUID;
 148
 149                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
 150                         res |= S_ISGID;
 151
 152                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 153                         res |= S_ISVTX;
 154         }
 155         return res;
 156 }
 157
 158 /**
 159  * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 160  * @uflags: flags to convert
 161  * @extended: if .u extensions are active
 162  */
 163
 164 int v9fs_uflags2omode(int uflags, int extended)
 165 {
 166         int ret;
 167
 168         ret = 0;
 169         switch (uflags&3) {
 170         default:
 171         case O_RDONLY:
 172                 ret = P9_OREAD;
 173                 break;
 174
 175         case O_WRONLY:
 176                 ret = P9_OWRITE;
 177                 break;
 178
 179         case O_RDWR:
 180                 ret = P9_ORDWR;
 181                 break;
 182         }
 183
 184         if (uflags & O_TRUNC)
 185                 ret |= P9_OTRUNC;
 186
 187         if (extended) {
 188                 if (uflags & O_EXCL)
 189                         ret |= P9_OEXCL;
 190
 191                 if (uflags & O_APPEND)
 192                         ret |= P9_OAPPEND;
 193         }
 194
 195         return ret;
 196 }
 197
 198 /**
 199  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 200  * @wstat: structure to initialize
 201  *
 202  */
 203
 204 void
 205 v9fs_blank_wstat(struct p9_wstat *wstat)
 206 {
 207         wstat->type = ~0;
 208         wstat->dev = ~0;
 209         wstat->qid.type = ~0;
 210         wstat->qid.version = ~0;
 211         *((long long *)&wstat->qid.path) = ~0;
 212         wstat->mode = ~0;
 213         wstat->atime = ~0;
 214         wstat->mtime = ~0;
 215         wstat->length = ~0;
 216         wstat->name = NULL;
 217         wstat->uid = NULL;
 218         wstat->gid = NULL;
 219         wstat->muid = NULL;
 220         wstat->n_uid = ~0;
 221         wstat->n_gid = ~0;
 222         wstat->n_muid = ~0;
 223         wstat->extension = NULL;
 224 }
 225
 226 /**
 227  * v9fs_alloc_inode - helper function to allocate an inode
 228  *
 229  */
 230 struct inode *v9fs_alloc_inode(struct super_block *sb)
 231 {
 232         struct v9fs_inode *v9inode;
 233         v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache,
 234                                                         GFP_KERNEL);
 235         if (!v9inode)
 236                 return NULL;
 237 #ifdef CONFIG_9P_FSCACHE
 238         v9inode->fscache = NULL;
 239         spin_lock_init(&v9inode->fscache_lock);
 240 #endif
 241         v9inode->writeback_fid = NULL;
 242         v9inode->cache_validity = 0;
 243         mutex_init(&v9inode->v_mutex);
 244         return &v9inode->vfs_inode;
 245 }
 246
 247 /**
 248  * v9fs_destroy_inode - destroy an inode
 249  *
 250  */
 251
 252 static void v9fs_i_callback(struct rcu_head *head)
 253 {
 254         struct inode *inode = container_of(head, struct inode, i_rcu);
 255         INIT_LIST_HEAD(&inode->i_dentry);
 256         kmem_cache_free(v9fs_inode_cache, V9FS_I(inode));
 257 }
 258
 259 void v9fs_destroy_inode(struct inode *inode)
 260 {
 261         call_rcu(&inode->i_rcu, v9fs_i_callback);
 262 }
 263
 264 int v9fs_init_inode(struct v9fs_session_info *v9ses,
 265                     struct inode *inode, int mode, dev_t rdev)
 266 {
 267         int err = 0;
 268
 269         inode_init_owner(inode, NULL, mode);
 270         inode->i_blocks = 0;
 271         inode->i_rdev = rdev;
 272         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 273         inode->i_mapping->a_ops = &v9fs_addr_operations;
 274
 275         switch (mode & S_IFMT) {
 276         case S_IFIFO:
 277         case S_IFBLK:
 278         case S_IFCHR:
 279         case S_IFSOCK:
 280                 if (v9fs_proto_dotl(v9ses)) {
 281                         inode->i_op = &v9fs_file_inode_operations_dotl;
 282                 } else if (v9fs_proto_dotu(v9ses)) {
 283                         inode->i_op = &v9fs_file_inode_operations;
 284                 } else {
 285                         p9_debug(P9_DEBUG_ERROR,
 286                                  "special files without extended mode\n");
 287                         err = -EINVAL;
 288                         goto error;
 289                 }
 290                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 291                 break;
 292         case S_IFREG:
 293                 if (v9fs_proto_dotl(v9ses)) {
 294                         inode->i_op = &v9fs_file_inode_operations_dotl;
 295                         if (v9ses->cache)
 296                                 inode->i_fop =
 297                                         &v9fs_cached_file_operations_dotl;
 298                         else
 299                                 inode->i_fop = &v9fs_file_operations_dotl;
 300                 } else {
 301                         inode->i_op = &v9fs_file_inode_operations;
 302                         if (v9ses->cache)
 303                                 inode->i_fop = &v9fs_cached_file_operations;
 304                         else
 305                                 inode->i_fop = &v9fs_file_operations;
 306                 }
 307
 308                 break;
 309         case S_IFLNK:
 310                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 311                         p9_debug(P9_DEBUG_ERROR,
 312                                  "extended modes used with legacy protocol\n");
 313                         err = -EINVAL;
 314                         goto error;
 315                 }
 316
 317                 if (v9fs_proto_dotl(v9ses))
 318                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
 319                 else
 320                         inode->i_op = &v9fs_symlink_inode_operations;
 321
 322                 break;
 323         case S_IFDIR:
 324                 inc_nlink(inode);
 325                 if (v9fs_proto_dotl(v9ses))
 326                         inode->i_op = &v9fs_dir_inode_operations_dotl;
 327                 else if (v9fs_proto_dotu(v9ses))
 328                         inode->i_op = &v9fs_dir_inode_operations_dotu;
 329                 else
 330                         inode->i_op = &v9fs_dir_inode_operations;
 331
 332                 if (v9fs_proto_dotl(v9ses))
 333                         inode->i_fop = &v9fs_dir_operations_dotl;
 334                 else
 335                         inode->i_fop = &v9fs_dir_operations;
 336
 337                 break;
 338         default:
 339                 p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
 340                          mode, mode & S_IFMT);
 341                 err = -EINVAL;
 342                 goto error;
 343         }
 344 error:
 345         return err;
 346
 347 }
 348
 349 /**
 350  * v9fs_get_inode - helper function to setup an inode
 351  * @sb: superblock
 352  * @mode: mode to setup inode with
 353  *
 354  */
 355
 356 struct inode *v9fs_get_inode(struct super_block *sb, int mode, dev_t rdev)
 357 {
 358         int err;
 359         struct inode *inode;
 360         struct v9fs_session_info *v9ses = sb->s_fs_info;
 361
 362         p9_debug(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 363
 364         inode = new_inode(sb);
 365         if (!inode) {
 366                 pr_warn("%s (%d): Problem allocating inode\n",
 367                         __func__, task_pid_nr(current));
 368                 return ERR_PTR(-ENOMEM);
 369         }
 370         err = v9fs_init_inode(v9ses, inode, mode, rdev);
 371         if (err) {
 372                 iput(inode);
 373                 return ERR_PTR(err);
 374         }
 375         return inode;
 376 }
 377
 378 /*
 379 static struct v9fs_fid*
 380 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 381 {
 382         int err;
 383         int nfid;
 384         struct v9fs_fid *ret;
 385         struct v9fs_fcall *fcall;
 386
 387         nfid = v9fs_get_idpool(&v9ses->fidpool);
 388         if (nfid < 0) {
 389                 eprintk(KERN_WARNING, "no free fids available\n");
 390                 return ERR_PTR(-ENOSPC);
 391         }
 392
 393         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 394                 &fcall);
 395
 396         if (err < 0) {
 397                 if (fcall && fcall->id == RWALK)
 398                         goto clunk_fid;
 399
 400                 PRINT_FCALL_ERROR("walk error", fcall);
 401                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 402                 goto error;
 403         }
 404
 405         kfree(fcall);
 406         fcall = NULL;
 407         ret = v9fs_fid_create(v9ses, nfid);
 408         if (!ret) {
 409                 err = -ENOMEM;
 410                 goto clunk_fid;
 411         }
 412
 413         err = v9fs_fid_insert(ret, dentry);
 414         if (err < 0) {
 415                 v9fs_fid_destroy(ret);
 416                 goto clunk_fid;
 417         }
 418
 419         return ret;
 420
 421 clunk_fid:
 422         v9fs_t_clunk(v9ses, nfid);
 423
 424 error:
 425         kfree(fcall);
 426         return ERR_PTR(err);
 427 }
 428 */
 429
 430
 431 /**
 432  * v9fs_clear_inode - release an inode
 433  * @inode: inode to release
 434  *
 435  */
 436 void v9fs_evict_inode(struct inode *inode)
 437 {
 438         struct v9fs_inode *v9inode = V9FS_I(inode);
 439
 440         truncate_inode_pages(inode->i_mapping, 0);
 441         end_writeback(inode);
 442         filemap_fdatawrite(inode->i_mapping);
 443
 444 #ifdef CONFIG_9P_FSCACHE
 445         v9fs_cache_inode_put_cookie(inode);
 446 #endif
 447         /* clunk the fid stashed in writeback_fid */
 448         if (v9inode->writeback_fid) {
 449                 p9_client_clunk(v9inode->writeback_fid);
 450                 v9inode->writeback_fid = NULL;
 451         }
 452 }
 453
 454 static int v9fs_test_inode(struct inode *inode, void *data)
 455 {
 456         int umode;
 457         dev_t rdev;
 458         struct v9fs_inode *v9inode = V9FS_I(inode);
 459         struct p9_wstat *st = (struct p9_wstat *)data;
 460         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode);
 461
 462         umode = p9mode2unixmode(v9ses, st, &rdev);
 463         /* don't match inode of different type */
 464         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
 465                 return 0;
 466
 467         /* compare qid details */
 468         if (memcmp(&v9inode->qid.version,
 469                    &st->qid.version, sizeof(v9inode->qid.version)))
 470                 return 0;
 471
 472         if (v9inode->qid.type != st->qid.type)
 473                 return 0;
 474         return 1;
 475 }
 476
 477 static int v9fs_test_new_inode(struct inode *inode, void *data)
 478 {
 479         return 0;
 480 }
 481
 482 static int v9fs_set_inode(struct inode *inode,  void *data)
 483 {
 484         struct v9fs_inode *v9inode = V9FS_I(inode);
 485         struct p9_wstat *st = (struct p9_wstat *)data;
 486
 487         memcpy(&v9inode->qid, &st->qid, sizeof(st->qid));
 488         return 0;
 489 }
 490
 491 static struct inode *v9fs_qid_iget(struct super_block *sb,
 492                                    struct p9_qid *qid,
 493                                    struct p9_wstat *st,
 494                                    int new)
 495 {
 496         dev_t rdev;
 497         int retval, umode;
 498         unsigned long i_ino;
 499         struct inode *inode;
 500         struct v9fs_session_info *v9ses = sb->s_fs_info;
 501         int (*test)(struct inode *, void *);
 502
 503         if (new)
 504                 test = v9fs_test_new_inode;
 505         else
 506                 test = v9fs_test_inode;
 507
 508         i_ino = v9fs_qid2ino(qid);
 509         inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st);
 510         if (!inode)
 511                 return ERR_PTR(-ENOMEM);
 512         if (!(inode->i_state & I_NEW))
 513                 return inode;
 514         /*
 515          * initialize the inode with the stat info
 516          * FIXME!! we may need support for stale inodes
 517          * later.
 518          */
 519         inode->i_ino = i_ino;
 520         umode = p9mode2unixmode(v9ses, st, &rdev);
 521         retval = v9fs_init_inode(v9ses, inode, umode, rdev);
 522         if (retval)
 523                 goto error;
 524
 525         v9fs_stat2inode(st, inode, sb);
 526 #ifdef CONFIG_9P_FSCACHE
 527         v9fs_cache_inode_get_cookie(inode);
 528 #endif
 529         unlock_new_inode(inode);
 530         return inode;
 531 error:
 532         unlock_new_inode(inode);
 533         iput(inode);
 534         return ERR_PTR(retval);
 535
 536 }
 537
 538 struct inode *
 539 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 540                     struct super_block *sb, int new)
 541 {
 542         struct p9_wstat *st;
 543         struct inode *inode = NULL;
 544
 545         st = p9_client_stat(fid);
 546         if (IS_ERR(st))
 547                 return ERR_CAST(st);
 548
 549         inode = v9fs_qid_iget(sb, &st->qid, st, new);
 550         p9stat_free(st);
 551         kfree(st);
 552         return inode;
 553 }
 554
 555 /**
 556  * v9fs_at_to_dotl_flags- convert Linux specific AT flags to
 557  * plan 9 AT flag.
 558  * @flags: flags to convert
 559  */
 560 static int v9fs_at_to_dotl_flags(int flags)
 561 {
 562         int rflags = 0;
 563         if (flags & AT_REMOVEDIR)
 564                 rflags |= P9_DOTL_AT_REMOVEDIR;
 565         return rflags;
 566 }
 567
 568 /**
 569  * v9fs_remove - helper function to remove files and directories
 570  * @dir: directory inode that is being deleted
 571  * @dentry:  dentry that is being deleted
 572  * @rmdir: removing a directory
 573  *
 574  */
 575
 576 static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags)
 577 {
 578         struct inode *inode;
 579         int retval = -EOPNOTSUPP;
 580         struct p9_fid *v9fid, *dfid;
 581         struct v9fs_session_info *v9ses;
 582
 583         p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n",
 584                  dir, dentry, flags);
 585
 586         v9ses = v9fs_inode2v9ses(dir);
 587         inode = dentry->d_inode;
 588         dfid = v9fs_fid_lookup(dentry->d_parent);
 589         if (IS_ERR(dfid)) {
 590                 retval = PTR_ERR(dfid);
 591                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval);
 592                 return retval;
 593         }
 594         if (v9fs_proto_dotl(v9ses))
 595                 retval = p9_client_unlinkat(dfid, dentry->d_name.name,
 596                                             v9fs_at_to_dotl_flags(flags));
 597         if (retval == -EOPNOTSUPP) {
 598                 /* Try the one based on path */
 599                 v9fid = v9fs_fid_clone(dentry);
 600                 if (IS_ERR(v9fid))
 601                         return PTR_ERR(v9fid);
 602                 retval = p9_client_remove(v9fid);
 603         }
 604         if (!retval) {
 605                 /*
 606                  * directories on unlink should have zero
 607                  * link count
 608                  */
 609                 if (flags & AT_REMOVEDIR) {
 610                         clear_nlink(inode);
 611                         drop_nlink(dir);
 612                 } else
 613                         drop_nlink(inode);
 614
 615                 v9fs_invalidate_inode_attr(inode);
 616                 v9fs_invalidate_inode_attr(dir);
 617         }
 618         return retval;
 619 }
 620
 621 /**
 622  * v9fs_create - Create a file
 623  * @v9ses: session information
 624  * @dir: directory that dentry is being created in
 625  * @dentry:  dentry that is being created
 626  * @extension: 9p2000.u extension string to support devices, etc.
 627  * @perm: create permissions
 628  * @mode: open mode
 629  *
 630  */
 631 static struct p9_fid *
 632 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 633                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 634 {
 635         int err;
 636         char *name;
 637         struct p9_fid *dfid, *ofid, *fid;
 638         struct inode *inode;
 639
 640         p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 641
 642         err = 0;
 643         ofid = NULL;
 644         fid = NULL;
 645         name = (char *) dentry->d_name.name;
 646         dfid = v9fs_fid_lookup(dentry->d_parent);
 647         if (IS_ERR(dfid)) {
 648                 err = PTR_ERR(dfid);
 649                 p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 650                 return ERR_PTR(err);
 651         }
 652
 653         /* clone a fid to use for creation */
 654         ofid = p9_client_walk(dfid, 0, NULL, 1);
 655         if (IS_ERR(ofid)) {
 656                 err = PTR_ERR(ofid);
 657                 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 658                 return ERR_PTR(err);
 659         }
 660
 661         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 662         if (err < 0) {
 663                 p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 664                 goto error;
 665         }
 666
 667         /* now walk from the parent so we can get unopened fid */
 668         fid = p9_client_walk(dfid, 1, &name, 1);
 669         if (IS_ERR(fid)) {
 670                 err = PTR_ERR(fid);
 671                 p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 672                 fid = NULL;
 673                 goto error;
 674         }
 675
 676         /* instantiate inode and assign the unopened fid to the dentry */
 677         inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 678         if (IS_ERR(inode)) {
 679                 err = PTR_ERR(inode);
 680                 p9_debug(P9_DEBUG_VFS, "inode creation failed %d\n", err);
 681                 goto error;
 682         }
 683         err = v9fs_fid_add(dentry, fid);
 684         if (err < 0)
 685                 goto error;
 686         d_instantiate(dentry, inode);
 687         return ofid;
 688 error:
 689         if (ofid)
 690                 p9_client_clunk(ofid);
 691
 692         if (fid)
 693                 p9_client_clunk(fid);
 694
 695         return ERR_PTR(err);
 696 }
 697
 698 /**
 699  * v9fs_vfs_create - VFS hook to create files
 700  * @dir: directory inode that is being created
 701  * @dentry:  dentry that is being deleted
 702  * @mode: create permissions
 703  * @nd: path information
 704  *
 705  */
 706
 707 static int
 708 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 709                 struct nameidata *nd)
 710 {
 711         int err;
 712         u32 perm;
 713         int flags;
 714         struct file *filp;
 715         struct v9fs_inode *v9inode;
 716         struct v9fs_session_info *v9ses;
 717         struct p9_fid *fid, *inode_fid;
 718
 719         err = 0;
 720         fid = NULL;
 721         v9ses = v9fs_inode2v9ses(dir);
 722         perm = unixmode2p9mode(v9ses, mode);
 723         if (nd)
 724                 flags = nd->intent.open.flags;
 725         else
 726                 flags = O_RDWR;
 727
 728         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 729                                 v9fs_uflags2omode(flags,
 730                                                 v9fs_proto_dotu(v9ses)));
 731         if (IS_ERR(fid)) {
 732                 err = PTR_ERR(fid);
 733                 fid = NULL;
 734                 goto error;
 735         }
 736
 737         v9fs_invalidate_inode_attr(dir);
 738         /* if we are opening a file, assign the open fid to the file */
 739         if (nd) {
 740                 v9inode = V9FS_I(dentry->d_inode);
 741                 mutex_lock(&v9inode->v_mutex);
 742                 if (v9ses->cache && !v9inode->writeback_fid &&
 743                     ((flags & O_ACCMODE) != O_RDONLY)) {
 744                         /*
 745                          * clone a fid and add it to writeback_fid
 746                          * we do it during open time instead of
 747                          * page dirty time via write_begin/page_mkwrite
 748                          * because we want write after unlink usecase
 749                          * to work.
 750                          */
 751                         inode_fid = v9fs_writeback_fid(dentry);
 752                         if (IS_ERR(inode_fid)) {
 753                                 err = PTR_ERR(inode_fid);
 754                                 mutex_unlock(&v9inode->v_mutex);
 755                                 goto error;
 756                         }
 757                         v9inode->writeback_fid = (void *) inode_fid;
 758                 }
 759                 mutex_unlock(&v9inode->v_mutex);
 760                 filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
 761                 if (IS_ERR(filp)) {
 762                         err = PTR_ERR(filp);
 763                         goto error;
 764                 }
 765
 766                 filp->private_data = fid;
 767 #ifdef CONFIG_9P_FSCACHE
 768                 if (v9ses->cache)
 769                         v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
 770 #endif
 771         } else
 772                 p9_client_clunk(fid);
 773
 774         return 0;
 775
 776 error:
 777         if (fid)
 778                 p9_client_clunk(fid);
 779
 780         return err;
 781 }
 782
 783 /**
 784  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 785  * @dir:  inode that is being unlinked
 786  * @dentry: dentry that is being unlinked
 787  * @mode: mode for new directory
 788  *
 789  */
 790
 791 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 792 {
 793         int err;
 794         u32 perm;
 795         struct p9_fid *fid;
 796         struct v9fs_session_info *v9ses;
 797
 798         p9_debug(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 799         err = 0;
 800         v9ses = v9fs_inode2v9ses(dir);
 801         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 802         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 803         if (IS_ERR(fid)) {
 804                 err = PTR_ERR(fid);
 805                 fid = NULL;
 806         } else {
 807                 inc_nlink(dir);
 808                 v9fs_invalidate_inode_attr(dir);
 809         }
 810
 811         if (fid)
 812                 p9_client_clunk(fid);
 813
 814         return err;
 815 }
 816
 817 /**
 818  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 819  * @dir:  inode that is being walked from
 820  * @dentry: dentry that is being walked to?
 821  * @nameidata: path data
 822  *
 823  */
 824
 825 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 826                                       struct nameidata *nameidata)
 827 {
 828         struct dentry *res;
 829         struct super_block *sb;
 830         struct v9fs_session_info *v9ses;
 831         struct p9_fid *dfid, *fid;
 832         struct inode *inode;
 833         char *name;
 834         int result = 0;
 835
 836         p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 837                  dir, dentry->d_name.name, dentry, nameidata);
 838
 839         if (dentry->d_name.len > NAME_MAX)
 840                 return ERR_PTR(-ENAMETOOLONG);
 841
 842         sb = dir->i_sb;
 843         v9ses = v9fs_inode2v9ses(dir);
 844         /* We can walk d_parent because we hold the dir->i_mutex */
 845         dfid = v9fs_fid_lookup(dentry->d_parent);
 846         if (IS_ERR(dfid))
 847                 return ERR_CAST(dfid);
 848
 849         name = (char *) dentry->d_name.name;
 850         fid = p9_client_walk(dfid, 1, &name, 1);
 851         if (IS_ERR(fid)) {
 852                 result = PTR_ERR(fid);
 853                 if (result == -ENOENT) {
 854                         inode = NULL;
 855                         goto inst_out;
 856                 }
 857
 858                 return ERR_PTR(result);
 859         }
 860         /*
 861          * Make sure we don't use a wrong inode due to parallel
 862          * unlink. For cached mode create calls request for new
 863          * inode. But with cache disabled, lookup should do this.
 864          */
 865         if (v9ses->cache)
 866                 inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb);
 867         else
 868                 inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb);
 869         if (IS_ERR(inode)) {
 870                 result = PTR_ERR(inode);
 871                 inode = NULL;
 872                 goto error;
 873         }
 874         result = v9fs_fid_add(dentry, fid);
 875         if (result < 0)
 876                 goto error_iput;
 877 inst_out:
 878         /*
 879          * If we had a rename on the server and a parallel lookup
 880          * for the new name, then make sure we instantiate with
 881          * the new name. ie look up for a/b, while on server somebody
 882          * moved b under k and client parallely did a lookup for
 883          * k/b.
 884          */
 885         res = d_materialise_unique(dentry, inode);
 886         if (!IS_ERR(res))
 887                 return res;
 888         result = PTR_ERR(res);
 889 error_iput:
 890         iput(inode);
 891 error:
 892         p9_client_clunk(fid);
 893
 894         return ERR_PTR(result);
 895 }
 896
 897 /**
 898  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 899  * @i:  inode that is being unlinked
 900  * @d: dentry that is being unlinked
 901  *
 902  */
 903
 904 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 905 {
 906         return v9fs_remove(i, d, 0);
 907 }
 908
 909 /**
 910  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 911  * @i:  inode that is being unlinked
 912  * @d: dentry that is being unlinked
 913  *
 914  */
 915
 916 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 917 {
 918         return v9fs_remove(i, d, AT_REMOVEDIR);
 919 }
 920
 921 /**
 922  * v9fs_vfs_rename - VFS hook to rename an inode
 923  * @old_dir:  old dir inode
 924  * @old_dentry: old dentry
 925  * @new_dir: new dir inode
 926  * @new_dentry: new dentry
 927  *
 928  */
 929
 930 int
 931 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 932                 struct inode *new_dir, struct dentry *new_dentry)
 933 {
 934         int retval;
 935         struct inode *old_inode;
 936         struct inode *new_inode;
 937         struct v9fs_session_info *v9ses;
 938         struct p9_fid *oldfid;
 939         struct p9_fid *olddirfid;
 940         struct p9_fid *newdirfid;
 941         struct p9_wstat wstat;
 942
 943         p9_debug(P9_DEBUG_VFS, "\n");
 944         retval = 0;
 945         old_inode = old_dentry->d_inode;
 946         new_inode = new_dentry->d_inode;
 947         v9ses = v9fs_inode2v9ses(old_inode);
 948         oldfid = v9fs_fid_lookup(old_dentry);
 949         if (IS_ERR(oldfid))
 950                 return PTR_ERR(oldfid);
 951
 952         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 953         if (IS_ERR(olddirfid)) {
 954                 retval = PTR_ERR(olddirfid);
 955                 goto done;
 956         }
 957
 958         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 959         if (IS_ERR(newdirfid)) {
 960                 retval = PTR_ERR(newdirfid);
 961                 goto clunk_olddir;
 962         }
 963
 964         down_write(&v9ses->rename_sem);
 965         if (v9fs_proto_dotl(v9ses)) {
 966                 retval = p9_client_renameat(olddirfid, old_dentry->d_name.name,
 967                                             newdirfid, new_dentry->d_name.name);
 968                 if (retval == -EOPNOTSUPP)
 969                         retval = p9_client_rename(oldfid, newdirfid,
 970                                                   new_dentry->d_name.name);
 971                 if (retval != -EOPNOTSUPP)
 972                         goto clunk_newdir;
 973         }
 974         if (old_dentry->d_parent != new_dentry->d_parent) {
 975                 /*
 976                  * 9P .u can only handle file rename in the same directory
 977                  */
 978
 979                 p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n");
 980                 retval = -EXDEV;
 981                 goto clunk_newdir;
 982         }
 983         v9fs_blank_wstat(&wstat);
 984         wstat.muid = v9ses->uname;
 985         wstat.name = (char *) new_dentry->d_name.name;
 986         retval = p9_client_wstat(oldfid, &wstat);
 987
 988 clunk_newdir:
 989         if (!retval) {
 990                 if (new_inode) {
 991                         if (S_ISDIR(new_inode->i_mode))
 992                                 clear_nlink(new_inode);
 993                         else
 994                                 drop_nlink(new_inode);
 995                 }
 996                 if (S_ISDIR(old_inode->i_mode)) {
 997                         if (!new_inode)
 998                                 inc_nlink(new_dir);
 999                         drop_nlink(old_dir);
1000                 }
1001                 v9fs_invalidate_inode_attr(old_inode);
1002                 v9fs_invalidate_inode_attr(old_dir);
1003                 v9fs_invalidate_inode_attr(new_dir);
1004
1005                 /* successful rename */
1006                 d_move(old_dentry, new_dentry);
1007         }
1008         up_write(&v9ses->rename_sem);
1009         p9_client_clunk(newdirfid);
1010
1011 clunk_olddir:
1012         p9_client_clunk(olddirfid);
1013
1014 done:
1015         return retval;
1016 }
1017
1018 /**
1019  * v9fs_vfs_getattr - retrieve file metadata
1020  * @mnt: mount information
1021  * @dentry: file to get attributes on
1022  * @stat: metadata structure to populate
1023  *
1024  */
1025
1026 static int
1027 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1028                  struct kstat *stat)
1029 {
1030         int err;
1031         struct v9fs_session_info *v9ses;
1032         struct p9_fid *fid;
1033         struct p9_wstat *st;
1034
1035         p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry);
1036         err = -EPERM;
1037         v9ses = v9fs_dentry2v9ses(dentry);
1038         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) {
1039                 generic_fillattr(dentry->d_inode, stat);
1040                 return 0;
1041         }
1042         fid = v9fs_fid_lookup(dentry);
1043         if (IS_ERR(fid))
1044                 return PTR_ERR(fid);
1045
1046         st = p9_client_stat(fid);
1047         if (IS_ERR(st))
1048                 return PTR_ERR(st);
1049
1050         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
1051         generic_fillattr(dentry->d_inode, stat);
1052
1053         p9stat_free(st);
1054         kfree(st);
1055         return 0;
1056 }
1057
1058 /**
1059  * v9fs_vfs_setattr - set file metadata
1060  * @dentry: file whose metadata to set
1061  * @iattr: metadata assignment structure
1062  *
1063  */
1064
1065 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
1066 {
1067         int retval;
1068         struct v9fs_session_info *v9ses;
1069         struct p9_fid *fid;
1070         struct p9_wstat wstat;
1071
1072         p9_debug(P9_DEBUG_VFS, "\n");
1073         retval = inode_change_ok(dentry->d_inode, iattr);
1074         if (retval)
1075                 return retval;
1076
1077         retval = -EPERM;
1078         v9ses = v9fs_dentry2v9ses(dentry);
1079         fid = v9fs_fid_lookup(dentry);
1080         if(IS_ERR(fid))
1081                 return PTR_ERR(fid);
1082
1083         v9fs_blank_wstat(&wstat);
1084         if (iattr->ia_valid & ATTR_MODE)
1085                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
1086
1087         if (iattr->ia_valid & ATTR_MTIME)
1088                 wstat.mtime = iattr->ia_mtime.tv_sec;
1089
1090         if (iattr->ia_valid & ATTR_ATIME)
1091                 wstat.atime = iattr->ia_atime.tv_sec;
1092
1093         if (iattr->ia_valid & ATTR_SIZE)
1094                 wstat.length = iattr->ia_size;
1095
1096         if (v9fs_proto_dotu(v9ses)) {
1097                 if (iattr->ia_valid & ATTR_UID)
1098                         wstat.n_uid = iattr->ia_uid;
1099
1100                 if (iattr->ia_valid & ATTR_GID)
1101                         wstat.n_gid = iattr->ia_gid;
1102         }
1103
1104         /* Write all dirty data */
1105         if (S_ISREG(dentry->d_inode->i_mode))
1106                 filemap_write_and_wait(dentry->d_inode->i_mapping);
1107
1108         retval = p9_client_wstat(fid, &wstat);
1109         if (retval < 0)
1110                 return retval;
1111
1112         if ((iattr->ia_valid & ATTR_SIZE) &&
1113             iattr->ia_size != i_size_read(dentry->d_inode))
1114                 truncate_setsize(dentry->d_inode, iattr->ia_size);
1115
1116         v9fs_invalidate_inode_attr(dentry->d_inode);
1117
1118         setattr_copy(dentry->d_inode, iattr);
1119         mark_inode_dirty(dentry->d_inode);
1120         return 0;
1121 }
1122
1123 /**
1124  * v9fs_stat2inode - populate an inode structure with mistat info
1125  * @stat: Plan 9 metadata (mistat) structure
1126  * @inode: inode to populate
1127  * @sb: superblock of filesystem
1128  *
1129  */
1130
1131 void
1132 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
1133         struct super_block *sb)
1134 {
1135         mode_t mode;
1136         char ext[32];
1137         char tag_name[14];
1138         unsigned int i_nlink;
1139         struct v9fs_session_info *v9ses = sb->s_fs_info;
1140         struct v9fs_inode *v9inode = V9FS_I(inode);
1141
1142         set_nlink(inode, 1);
1143
1144         inode->i_atime.tv_sec = stat->atime;
1145         inode->i_mtime.tv_sec = stat->mtime;
1146         inode->i_ctime.tv_sec = stat->mtime;
1147
1148         inode->i_uid = v9ses->dfltuid;
1149         inode->i_gid = v9ses->dfltgid;
1150
1151         if (v9fs_proto_dotu(v9ses)) {
1152                 inode->i_uid = stat->n_uid;
1153                 inode->i_gid = stat->n_gid;
1154         }
1155         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
1156                 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
1157                         /*
1158                          * Hadlink support got added later to
1159                          * to the .u extension. So there can be
1160                          * server out there that doesn't support
1161                          * this even with .u extension. So check
1162                          * for non NULL stat->extension
1163                          */
1164                         strncpy(ext, stat->extension, sizeof(ext));
1165                         /* HARDLINKCOUNT %u */
1166                         sscanf(ext, "%13s %u", tag_name, &i_nlink);
1167                         if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
1168                                 set_nlink(inode, i_nlink);
1169                 }
1170         }
1171         mode = stat->mode & S_IALLUGO;
1172         mode |= inode->i_mode & ~S_IALLUGO;
1173         inode->i_mode = mode;
1174         i_size_write(inode, stat->length);
1175
1176         /* not real number of blocks, but 512 byte ones ... */
1177         inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
1178         v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR;
1179 }
1180
1181 /**
1182  * v9fs_qid2ino - convert qid into inode number
1183  * @qid: qid to hash
1184  *
1185  * BUG: potential for inode number collisions?
1186  */
1187
1188 ino_t v9fs_qid2ino(struct p9_qid *qid)
1189 {
1190         u64 path = qid->path + 2;
1191         ino_t i = 0;
1192
1193         if (sizeof(ino_t) == sizeof(path))
1194                 memcpy(&i, &path, sizeof(ino_t));
1195         else
1196                 i = (ino_t) (path ^ (path >> 32));
1197
1198         return i;
1199 }
1200
1201 /**
1202  * v9fs_readlink - read a symlink's location (internal version)
1203  * @dentry: dentry for symlink
1204  * @buffer: buffer to load symlink location into
1205  * @buflen: length of buffer
1206  *
1207  */
1208
1209 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1210 {
1211         int retval;
1212
1213         struct v9fs_session_info *v9ses;
1214         struct p9_fid *fid;
1215         struct p9_wstat *st;
1216
1217         p9_debug(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1218         retval = -EPERM;
1219         v9ses = v9fs_dentry2v9ses(dentry);
1220         fid = v9fs_fid_lookup(dentry);
1221         if (IS_ERR(fid))
1222                 return PTR_ERR(fid);
1223
1224         if (!v9fs_proto_dotu(v9ses))
1225                 return -EBADF;
1226
1227         st = p9_client_stat(fid);
1228         if (IS_ERR(st))
1229                 return PTR_ERR(st);
1230
1231         if (!(st->mode & P9_DMSYMLINK)) {
1232                 retval = -EINVAL;
1233                 goto done;
1234         }
1235
1236         /* copy extension buffer into buffer */
1237         strncpy(buffer, st->extension, buflen);
1238
1239         p9_debug(P9_DEBUG_VFS, "%s -> %s (%s)\n",
1240                  dentry->d_name.name, st->extension, buffer);
1241
1242         retval = strnlen(buffer, buflen);
1243 done:
1244         p9stat_free(st);
1245         kfree(st);
1246         return retval;
1247 }
1248
1249 /**
1250  * v9fs_vfs_follow_link - follow a symlink path
1251  * @dentry: dentry for symlink
1252  * @nd: nameidata
1253  *
1254  */
1255
1256 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1257 {
1258         int len = 0;
1259         char *link = __getname();
1260
1261         p9_debug(P9_DEBUG_VFS, "%s\n", dentry->d_name.name);
1262
1263         if (!link)
1264                 link = ERR_PTR(-ENOMEM);
1265         else {
1266                 len = v9fs_readlink(dentry, link, PATH_MAX);
1267
1268                 if (len < 0) {
1269                         __putname(link);
1270                         link = ERR_PTR(len);
1271                 } else
1272                         link[min(len, PATH_MAX-1)] = 0;
1273         }
1274         nd_set_link(nd, link);
1275
1276         return NULL;
1277 }
1278
1279 /**
1280  * v9fs_vfs_put_link - release a symlink path
1281  * @dentry: dentry for symlink
1282  * @nd: nameidata
1283  * @p: unused
1284  *
1285  */
1286
1287 void
1288 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1289 {
1290         char *s = nd_get_link(nd);
1291
1292         p9_debug(P9_DEBUG_VFS, " %s %s\n",
1293                  dentry->d_name.name, IS_ERR(s) ? "<error>" : s);
1294         if (!IS_ERR(s))
1295                 __putname(s);
1296 }
1297
1298 /**
1299  * v9fs_vfs_mkspecial - create a special file
1300  * @dir: inode to create special file in
1301  * @dentry: dentry to create
1302  * @mode: mode to create special file
1303  * @extension: 9p2000.u format extension string representing special file
1304  *
1305  */
1306
1307 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1308         int mode, const char *extension)
1309 {
1310         u32 perm;
1311         struct p9_fid *fid;
1312         struct v9fs_session_info *v9ses;
1313
1314         v9ses = v9fs_inode2v9ses(dir);
1315         if (!v9fs_proto_dotu(v9ses)) {
1316                 p9_debug(P9_DEBUG_ERROR, "not extended\n");
1317                 return -EPERM;
1318         }
1319
1320         perm = unixmode2p9mode(v9ses, mode);
1321         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1322                                                                 P9_OREAD);
1323         if (IS_ERR(fid))
1324                 return PTR_ERR(fid);
1325
1326         v9fs_invalidate_inode_attr(dir);
1327         p9_client_clunk(fid);
1328         return 0;
1329 }
1330
1331 /**
1332  * v9fs_vfs_symlink - helper function to create symlinks
1333  * @dir: directory inode containing symlink
1334  * @dentry: dentry for symlink
1335  * @symname: symlink data
1336  *
1337  * See Also: 9P2000.u RFC for more information
1338  *
1339  */
1340
1341 static int
1342 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1343 {
1344         p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1345                  dir->i_ino, dentry->d_name.name, symname);
1346
1347         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1348 }
1349
1350 /**
1351  * v9fs_vfs_link - create a hardlink
1352  * @old_dentry: dentry for file to link to
1353  * @dir: inode destination for new link
1354  * @dentry: dentry for link
1355  *
1356  */
1357
1358 static int
1359 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1360               struct dentry *dentry)
1361 {
1362         int retval;
1363         char *name;
1364         struct p9_fid *oldfid;
1365
1366         p9_debug(P9_DEBUG_VFS, " %lu,%s,%s\n",
1367                  dir->i_ino, dentry->d_name.name, old_dentry->d_name.name);
1368
1369         oldfid = v9fs_fid_clone(old_dentry);
1370         if (IS_ERR(oldfid))
1371                 return PTR_ERR(oldfid);
1372
1373         name = __getname();
1374         if (unlikely(!name)) {
1375                 retval = -ENOMEM;
1376                 goto clunk_fid;
1377         }
1378
1379         sprintf(name, "%d\n", oldfid->fid);
1380         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1381         __putname(name);
1382         if (!retval) {
1383                 v9fs_refresh_inode(oldfid, old_dentry->d_inode);
1384                 v9fs_invalidate_inode_attr(dir);
1385         }
1386 clunk_fid:
1387         p9_client_clunk(oldfid);
1388         return retval;
1389 }
1390
1391 /**
1392  * v9fs_vfs_mknod - create a special file
1393  * @dir: inode destination for new link
1394  * @dentry: dentry for file
1395  * @mode: mode for creation
1396  * @rdev: device associated with special file
1397  *
1398  */
1399
1400 static int
1401 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1402 {
1403         int retval;
1404         char *name;
1405
1406         p9_debug(P9_DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n",
1407                  dir->i_ino, dentry->d_name.name, mode,
1408                  MAJOR(rdev), MINOR(rdev));
1409
1410         if (!new_valid_dev(rdev))
1411                 return -EINVAL;
1412
1413         name = __getname();
1414         if (!name)
1415                 return -ENOMEM;
1416         /* build extension */
1417         if (S_ISBLK(mode))
1418                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1419         else if (S_ISCHR(mode))
1420                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1421         else if (S_ISFIFO(mode))
1422                 *name = 0;
1423         else if (S_ISSOCK(mode))
1424                 *name = 0;
1425         else {
1426                 __putname(name);
1427                 return -EINVAL;
1428         }
1429
1430         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1431         __putname(name);
1432
1433         return retval;
1434 }
1435
1436 int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode)
1437 {
1438         int umode;
1439         dev_t rdev;
1440         loff_t i_size;
1441         struct p9_wstat *st;
1442         struct v9fs_session_info *v9ses;
1443
1444         v9ses = v9fs_inode2v9ses(inode);
1445         st = p9_client_stat(fid);
1446         if (IS_ERR(st))
1447                 return PTR_ERR(st);
1448         /*
1449          * Don't update inode if the file type is different
1450          */
1451         umode = p9mode2unixmode(v9ses, st, &rdev);
1452         if ((inode->i_mode & S_IFMT) != (umode & S_IFMT))
1453                 goto out;
1454
1455         spin_lock(&inode->i_lock);
1456         /*
1457          * We don't want to refresh inode->i_size,
1458          * because we may have cached data
1459          */
1460         i_size = inode->i_size;
1461         v9fs_stat2inode(st, inode, inode->i_sb);
1462         if (v9ses->cache)
1463                 inode->i_size = i_size;
1464         spin_unlock(&inode->i_lock);
1465 out:
1466         p9stat_free(st);
1467         kfree(st);
1468         return 0;
1469 }
1470
1471 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1472         .create = v9fs_vfs_create,
1473         .lookup = v9fs_vfs_lookup,
1474         .symlink = v9fs_vfs_symlink,
1475         .link = v9fs_vfs_link,
1476         .unlink = v9fs_vfs_unlink,
1477         .mkdir = v9fs_vfs_mkdir,
1478         .rmdir = v9fs_vfs_rmdir,
1479         .mknod = v9fs_vfs_mknod,
1480         .rename = v9fs_vfs_rename,
1481         .getattr = v9fs_vfs_getattr,
1482         .setattr = v9fs_vfs_setattr,
1483 };
1484
1485 static const struct inode_operations v9fs_dir_inode_operations = {
1486         .create = v9fs_vfs_create,
1487         .lookup = v9fs_vfs_lookup,
1488         .unlink = v9fs_vfs_unlink,
1489         .mkdir = v9fs_vfs_mkdir,
1490         .rmdir = v9fs_vfs_rmdir,
1491         .mknod = v9fs_vfs_mknod,
1492         .rename = v9fs_vfs_rename,
1493         .getattr = v9fs_vfs_getattr,
1494         .setattr = v9fs_vfs_setattr,
1495 };
1496
1497 static const struct inode_operations v9fs_file_inode_operations = {
1498         .getattr = v9fs_vfs_getattr,
1499         .setattr = v9fs_vfs_setattr,
1500 };
1501
1502 static const struct inode_operations v9fs_symlink_inode_operations = {
1503         .readlink = generic_readlink,
1504         .follow_link = v9fs_vfs_follow_link,
1505         .put_link = v9fs_vfs_put_link,
1506         .getattr = v9fs_vfs_getattr,
1507         .setattr = v9fs_vfs_setattr,
1508 };
1509