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 #ifdef CONFIG_9P_FSCACHE
 207 /**
 208  * v9fs_alloc_inode - helper function to allocate an inode
 209  * This callback is executed before setting up the inode so that we
 210  * can associate a vcookie with each inode.
 211  *
 212  */
 213
 214 struct inode *v9fs_alloc_inode(struct super_block *sb)
 215 {
 216         struct v9fs_cookie *vcookie;
 217         vcookie = (struct v9fs_cookie *)kmem_cache_alloc(vcookie_cache,
 218                                                          GFP_KERNEL);
 219         if (!vcookie)
 220                 return NULL;
 221
 222         vcookie->fscache = NULL;
 223         vcookie->qid = NULL;
 224         spin_lock_init(&vcookie->lock);
 225         return &vcookie->inode;
 226 }
 227
 228 /**
 229  * v9fs_destroy_inode - destroy an inode
 230  *
 231  */
 232
 233 static void v9fs_i_callback(struct rcu_head *head)
 234 {
 235         struct inode *inode = container_of(head, struct inode, i_rcu);
 236         INIT_LIST_HEAD(&inode->i_dentry);
 237         kmem_cache_free(vcookie_cache, v9fs_inode2cookie(inode));
 238 }
 239
 240 void v9fs_destroy_inode(struct inode *inode)
 241 {
 242         call_rcu(&inode->i_rcu, v9fs_i_callback);
 243 }
 244 #endif
 245
 246 /**
 247  * v9fs_get_inode - helper function to setup an inode
 248  * @sb: superblock
 249  * @mode: mode to setup inode with
 250  *
 251  */
 252
 253 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 254 {
 255         int err;
 256         struct inode *inode;
 257         struct v9fs_session_info *v9ses = sb->s_fs_info;
 258
 259         P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 260
 261         inode = new_inode(sb);
 262         if (!inode) {
 263                 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
 264                 return ERR_PTR(-ENOMEM);
 265         }
 266
 267         inode_init_owner(inode, NULL, mode);
 268         inode->i_blocks = 0;
 269         inode->i_rdev = 0;
 270         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 271         inode->i_mapping->a_ops = &v9fs_addr_operations;
 272
 273         switch (mode & S_IFMT) {
 274         case S_IFIFO:
 275         case S_IFBLK:
 276         case S_IFCHR:
 277         case S_IFSOCK:
 278                 if (v9fs_proto_dotl(v9ses)) {
 279                         inode->i_op = &v9fs_file_inode_operations_dotl;
 280                         inode->i_fop = &v9fs_file_operations_dotl;
 281                 } else if (v9fs_proto_dotu(v9ses)) {
 282                         inode->i_op = &v9fs_file_inode_operations;
 283                         inode->i_fop = &v9fs_file_operations;
 284                 } else {
 285                         P9_DPRINTK(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
 310         case S_IFLNK:
 311                 if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) {
 312                         P9_DPRINTK(P9_DEBUG_ERROR, "extended modes used with "
 313                                                 "legacy protocol.\n");
 314                         err = -EINVAL;
 315                         goto error;
 316                 }
 317
 318                 if (v9fs_proto_dotl(v9ses))
 319                         inode->i_op = &v9fs_symlink_inode_operations_dotl;
 320                 else
 321                         inode->i_op = &v9fs_symlink_inode_operations;
 322
 323                 break;
 324         case S_IFDIR:
 325                 inc_nlink(inode);
 326                 if (v9fs_proto_dotl(v9ses))
 327                         inode->i_op = &v9fs_dir_inode_operations_dotl;
 328                 else if (v9fs_proto_dotu(v9ses))
 329                         inode->i_op = &v9fs_dir_inode_operations_dotu;
 330                 else
 331                         inode->i_op = &v9fs_dir_inode_operations;
 332
 333                 if (v9fs_proto_dotl(v9ses))
 334                         inode->i_fop = &v9fs_dir_operations_dotl;
 335                 else
 336                         inode->i_fop = &v9fs_dir_operations;
 337
 338                 break;
 339         default:
 340                 P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
 341                            mode, mode & S_IFMT);
 342                 err = -EINVAL;
 343                 goto error;
 344         }
 345
 346         return inode;
 347
 348 error:
 349         iput(inode);
 350         return ERR_PTR(err);
 351 }
 352
 353 /*
 354 static struct v9fs_fid*
 355 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 356 {
 357         int err;
 358         int nfid;
 359         struct v9fs_fid *ret;
 360         struct v9fs_fcall *fcall;
 361
 362         nfid = v9fs_get_idpool(&v9ses->fidpool);
 363         if (nfid < 0) {
 364                 eprintk(KERN_WARNING, "no free fids available\n");
 365                 return ERR_PTR(-ENOSPC);
 366         }
 367
 368         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 369                 &fcall);
 370
 371         if (err < 0) {
 372                 if (fcall && fcall->id == RWALK)
 373                         goto clunk_fid;
 374
 375                 PRINT_FCALL_ERROR("walk error", fcall);
 376                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 377                 goto error;
 378         }
 379
 380         kfree(fcall);
 381         fcall = NULL;
 382         ret = v9fs_fid_create(v9ses, nfid);
 383         if (!ret) {
 384                 err = -ENOMEM;
 385                 goto clunk_fid;
 386         }
 387
 388         err = v9fs_fid_insert(ret, dentry);
 389         if (err < 0) {
 390                 v9fs_fid_destroy(ret);
 391                 goto clunk_fid;
 392         }
 393
 394         return ret;
 395
 396 clunk_fid:
 397         v9fs_t_clunk(v9ses, nfid);
 398
 399 error:
 400         kfree(fcall);
 401         return ERR_PTR(err);
 402 }
 403 */
 404
 405
 406 /**
 407  * v9fs_clear_inode - release an inode
 408  * @inode: inode to release
 409  *
 410  */
 411 void v9fs_evict_inode(struct inode *inode)
 412 {
 413         truncate_inode_pages(inode->i_mapping, 0);
 414         end_writeback(inode);
 415         filemap_fdatawrite(inode->i_mapping);
 416
 417 #ifdef CONFIG_9P_FSCACHE
 418         v9fs_cache_inode_put_cookie(inode);
 419 #endif
 420 }
 421
 422 struct inode *
 423 v9fs_inode(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 424         struct super_block *sb)
 425 {
 426         int err, umode;
 427         struct inode *ret = NULL;
 428         struct p9_wstat *st;
 429
 430         st = p9_client_stat(fid);
 431         if (IS_ERR(st))
 432                 return ERR_CAST(st);
 433
 434         umode = p9mode2unixmode(v9ses, st->mode);
 435         ret = v9fs_get_inode(sb, umode);
 436         if (IS_ERR(ret)) {
 437                 err = PTR_ERR(ret);
 438                 goto error;
 439         }
 440
 441         v9fs_stat2inode(st, ret, sb);
 442         ret->i_ino = v9fs_qid2ino(&st->qid);
 443
 444 #ifdef CONFIG_9P_FSCACHE
 445         v9fs_vcookie_set_qid(ret, &st->qid);
 446         v9fs_cache_inode_get_cookie(ret);
 447 #endif
 448         p9stat_free(st);
 449         kfree(st);
 450         return ret;
 451 error:
 452         p9stat_free(st);
 453         kfree(st);
 454         return ERR_PTR(err);
 455 }
 456
 457 /**
 458  * v9fs_remove - helper function to remove files and directories
 459  * @dir: directory inode that is being deleted
 460  * @file:  dentry that is being deleted
 461  * @rmdir: removing a directory
 462  *
 463  */
 464
 465 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 466 {
 467         int retval;
 468         struct inode *file_inode;
 469         struct p9_fid *v9fid;
 470
 471         P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 472                 rmdir);
 473
 474         file_inode = file->d_inode;
 475         v9fid = v9fs_fid_clone(file);
 476         if (IS_ERR(v9fid))
 477                 return PTR_ERR(v9fid);
 478
 479         retval = p9_client_remove(v9fid);
 480         if (!retval)
 481                 drop_nlink(file_inode);
 482         return retval;
 483 }
 484
 485 /**
 486  * v9fs_create - Create a file
 487  * @v9ses: session information
 488  * @dir: directory that dentry is being created in
 489  * @dentry:  dentry that is being created
 490  * @extension: 9p2000.u extension string to support devices, etc.
 491  * @perm: create permissions
 492  * @mode: open mode
 493  *
 494  */
 495 static struct p9_fid *
 496 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 497                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 498 {
 499         int err;
 500         char *name;
 501         struct p9_fid *dfid, *ofid, *fid;
 502         struct inode *inode;
 503
 504         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 505
 506         err = 0;
 507         ofid = NULL;
 508         fid = NULL;
 509         name = (char *) dentry->d_name.name;
 510         dfid = v9fs_fid_lookup(dentry->d_parent);
 511         if (IS_ERR(dfid)) {
 512                 err = PTR_ERR(dfid);
 513                 P9_DPRINTK(P9_DEBUG_VFS, "fid lookup failed %d\n", err);
 514                 return ERR_PTR(err);
 515         }
 516
 517         /* clone a fid to use for creation */
 518         ofid = p9_client_walk(dfid, 0, NULL, 1);
 519         if (IS_ERR(ofid)) {
 520                 err = PTR_ERR(ofid);
 521                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 522                 return ERR_PTR(err);
 523         }
 524
 525         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 526         if (err < 0) {
 527                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 528                 goto error;
 529         }
 530
 531         /* now walk from the parent so we can get unopened fid */
 532         fid = p9_client_walk(dfid, 1, &name, 1);
 533         if (IS_ERR(fid)) {
 534                 err = PTR_ERR(fid);
 535                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 536                 fid = NULL;
 537                 goto error;
 538         }
 539
 540         /* instantiate inode and assign the unopened fid to the dentry */
 541         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 542         if (IS_ERR(inode)) {
 543                 err = PTR_ERR(inode);
 544                 P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
 545                 goto error;
 546         }
 547         d_instantiate(dentry, inode);
 548         err = v9fs_fid_add(dentry, fid);
 549         if (err < 0)
 550                 goto error;
 551
 552         return ofid;
 553
 554 error:
 555         if (ofid)
 556                 p9_client_clunk(ofid);
 557
 558         if (fid)
 559                 p9_client_clunk(fid);
 560
 561         return ERR_PTR(err);
 562 }
 563
 564 /**
 565  * v9fs_vfs_create - VFS hook to create files
 566  * @dir: directory inode that is being created
 567  * @dentry:  dentry that is being deleted
 568  * @mode: create permissions
 569  * @nd: path information
 570  *
 571  */
 572
 573 static int
 574 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 575                 struct nameidata *nd)
 576 {
 577         int err;
 578         u32 perm;
 579         int flags;
 580         struct v9fs_session_info *v9ses;
 581         struct p9_fid *fid;
 582         struct file *filp;
 583
 584         err = 0;
 585         fid = NULL;
 586         v9ses = v9fs_inode2v9ses(dir);
 587         perm = unixmode2p9mode(v9ses, mode);
 588         if (nd && nd->flags & LOOKUP_OPEN)
 589                 flags = nd->intent.open.flags - 1;
 590         else
 591                 flags = O_RDWR;
 592
 593         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 594                                 v9fs_uflags2omode(flags,
 595                                                 v9fs_proto_dotu(v9ses)));
 596         if (IS_ERR(fid)) {
 597                 err = PTR_ERR(fid);
 598                 fid = NULL;
 599                 goto error;
 600         }
 601
 602         /* if we are opening a file, assign the open fid to the file */
 603         if (nd && nd->flags & LOOKUP_OPEN) {
 604                 filp = lookup_instantiate_filp(nd, dentry, generic_file_open);
 605                 if (IS_ERR(filp)) {
 606                         err = PTR_ERR(filp);
 607                         goto error;
 608                 }
 609
 610                 filp->private_data = fid;
 611 #ifdef CONFIG_9P_FSCACHE
 612                 if (v9ses->cache)
 613                         v9fs_cache_inode_set_cookie(dentry->d_inode, filp);
 614 #endif
 615         } else
 616                 p9_client_clunk(fid);
 617
 618         return 0;
 619
 620 error:
 621         if (fid)
 622                 p9_client_clunk(fid);
 623
 624         return err;
 625 }
 626
 627 /**
 628  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 629  * @dir:  inode that is being unlinked
 630  * @dentry: dentry that is being unlinked
 631  * @mode: mode for new directory
 632  *
 633  */
 634
 635 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 636 {
 637         int err;
 638         u32 perm;
 639         struct v9fs_session_info *v9ses;
 640         struct p9_fid *fid;
 641
 642         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 643         err = 0;
 644         v9ses = v9fs_inode2v9ses(dir);
 645         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 646         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 647         if (IS_ERR(fid)) {
 648                 err = PTR_ERR(fid);
 649                 fid = NULL;
 650         }
 651
 652         if (fid)
 653                 p9_client_clunk(fid);
 654
 655         return err;
 656 }
 657
 658 /**
 659  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 660  * @dir:  inode that is being walked from
 661  * @dentry: dentry that is being walked to?
 662  * @nameidata: path data
 663  *
 664  */
 665
 666 struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 667                                       struct nameidata *nameidata)
 668 {
 669         struct super_block *sb;
 670         struct v9fs_session_info *v9ses;
 671         struct p9_fid *dfid, *fid;
 672         struct inode *inode;
 673         char *name;
 674         int result = 0;
 675
 676         P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 677                 dir, dentry->d_name.name, dentry, nameidata);
 678
 679         if (dentry->d_name.len > NAME_MAX)
 680                 return ERR_PTR(-ENAMETOOLONG);
 681
 682         sb = dir->i_sb;
 683         v9ses = v9fs_inode2v9ses(dir);
 684         /* We can walk d_parent because we hold the dir->i_mutex */
 685         dfid = v9fs_fid_lookup(dentry->d_parent);
 686         if (IS_ERR(dfid))
 687                 return ERR_CAST(dfid);
 688
 689         name = (char *) dentry->d_name.name;
 690         fid = p9_client_walk(dfid, 1, &name, 1);
 691         if (IS_ERR(fid)) {
 692                 result = PTR_ERR(fid);
 693                 if (result == -ENOENT) {
 694                         inode = NULL;
 695                         goto inst_out;
 696                 }
 697
 698                 return ERR_PTR(result);
 699         }
 700
 701         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 702         if (IS_ERR(inode)) {
 703                 result = PTR_ERR(inode);
 704                 inode = NULL;
 705                 goto error;
 706         }
 707
 708         result = v9fs_fid_add(dentry, fid);
 709         if (result < 0)
 710                 goto error_iput;
 711
 712 inst_out:
 713         d_add(dentry, inode);
 714         return NULL;
 715
 716 error_iput:
 717         iput(inode);
 718 error:
 719         p9_client_clunk(fid);
 720
 721         return ERR_PTR(result);
 722 }
 723
 724 /**
 725  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 726  * @i:  inode that is being unlinked
 727  * @d: dentry that is being unlinked
 728  *
 729  */
 730
 731 int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 732 {
 733         return v9fs_remove(i, d, 0);
 734 }
 735
 736 /**
 737  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 738  * @i:  inode that is being unlinked
 739  * @d: dentry that is being unlinked
 740  *
 741  */
 742
 743 int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 744 {
 745         return v9fs_remove(i, d, 1);
 746 }
 747
 748 /**
 749  * v9fs_vfs_rename - VFS hook to rename an inode
 750  * @old_dir:  old dir inode
 751  * @old_dentry: old dentry
 752  * @new_dir: new dir inode
 753  * @new_dentry: new dentry
 754  *
 755  */
 756
 757 int
 758 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 759                 struct inode *new_dir, struct dentry *new_dentry)
 760 {
 761         struct inode *old_inode;
 762         struct v9fs_session_info *v9ses;
 763         struct p9_fid *oldfid;
 764         struct p9_fid *olddirfid;
 765         struct p9_fid *newdirfid;
 766         struct p9_wstat wstat;
 767         int retval;
 768
 769         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 770         retval = 0;
 771         old_inode = old_dentry->d_inode;
 772         v9ses = v9fs_inode2v9ses(old_inode);
 773         oldfid = v9fs_fid_lookup(old_dentry);
 774         if (IS_ERR(oldfid))
 775                 return PTR_ERR(oldfid);
 776
 777         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 778         if (IS_ERR(olddirfid)) {
 779                 retval = PTR_ERR(olddirfid);
 780                 goto done;
 781         }
 782
 783         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 784         if (IS_ERR(newdirfid)) {
 785                 retval = PTR_ERR(newdirfid);
 786                 goto clunk_olddir;
 787         }
 788
 789         down_write(&v9ses->rename_sem);
 790         if (v9fs_proto_dotl(v9ses)) {
 791                 retval = p9_client_rename(oldfid, newdirfid,
 792                                         (char *) new_dentry->d_name.name);
 793                 if (retval != -ENOSYS)
 794                         goto clunk_newdir;
 795         }
 796         if (old_dentry->d_parent != new_dentry->d_parent) {
 797                 /*
 798                  * 9P .u can only handle file rename in the same directory
 799                  */
 800
 801                 P9_DPRINTK(P9_DEBUG_ERROR,
 802                                 "old dir and new dir are different\n");
 803                 retval = -EXDEV;
 804                 goto clunk_newdir;
 805         }
 806         v9fs_blank_wstat(&wstat);
 807         wstat.muid = v9ses->uname;
 808         wstat.name = (char *) new_dentry->d_name.name;
 809         retval = p9_client_wstat(oldfid, &wstat);
 810
 811 clunk_newdir:
 812         if (!retval)
 813                 /* successful rename */
 814                 d_move(old_dentry, new_dentry);
 815         up_write(&v9ses->rename_sem);
 816         p9_client_clunk(newdirfid);
 817
 818 clunk_olddir:
 819         p9_client_clunk(olddirfid);
 820
 821 done:
 822         return retval;
 823 }
 824
 825 /**
 826  * v9fs_vfs_getattr - retrieve file metadata
 827  * @mnt: mount information
 828  * @dentry: file to get attributes on
 829  * @stat: metadata structure to populate
 830  *
 831  */
 832
 833 static int
 834 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 835                  struct kstat *stat)
 836 {
 837         int err;
 838         struct v9fs_session_info *v9ses;
 839         struct p9_fid *fid;
 840         struct p9_wstat *st;
 841
 842         P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 843         err = -EPERM;
 844         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 845         if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE)
 846                 return simple_getattr(mnt, dentry, stat);
 847
 848         fid = v9fs_fid_lookup(dentry);
 849         if (IS_ERR(fid))
 850                 return PTR_ERR(fid);
 851
 852         st = p9_client_stat(fid);
 853         if (IS_ERR(st))
 854                 return PTR_ERR(st);
 855
 856         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
 857                 generic_fillattr(dentry->d_inode, stat);
 858
 859         p9stat_free(st);
 860         kfree(st);
 861         return 0;
 862 }
 863
 864 /**
 865  * v9fs_vfs_setattr - set file metadata
 866  * @dentry: file whose metadata to set
 867  * @iattr: metadata assignment structure
 868  *
 869  */
 870
 871 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 872 {
 873         int retval;
 874         struct v9fs_session_info *v9ses;
 875         struct p9_fid *fid;
 876         struct p9_wstat wstat;
 877
 878         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 879         retval = -EPERM;
 880         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 881         fid = v9fs_fid_lookup(dentry);
 882         if(IS_ERR(fid))
 883                 return PTR_ERR(fid);
 884
 885         v9fs_blank_wstat(&wstat);
 886         if (iattr->ia_valid & ATTR_MODE)
 887                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 888
 889         if (iattr->ia_valid & ATTR_MTIME)
 890                 wstat.mtime = iattr->ia_mtime.tv_sec;
 891
 892         if (iattr->ia_valid & ATTR_ATIME)
 893                 wstat.atime = iattr->ia_atime.tv_sec;
 894
 895         if (iattr->ia_valid & ATTR_SIZE)
 896                 wstat.length = iattr->ia_size;
 897
 898         if (v9fs_proto_dotu(v9ses)) {
 899                 if (iattr->ia_valid & ATTR_UID)
 900                         wstat.n_uid = iattr->ia_uid;
 901
 902                 if (iattr->ia_valid & ATTR_GID)
 903                         wstat.n_gid = iattr->ia_gid;
 904         }
 905
 906         retval = p9_client_wstat(fid, &wstat);
 907         if (retval < 0)
 908                 return retval;
 909
 910         if ((iattr->ia_valid & ATTR_SIZE) &&
 911             iattr->ia_size != i_size_read(dentry->d_inode)) {
 912                 retval = vmtruncate(dentry->d_inode, iattr->ia_size);
 913                 if (retval)
 914                         return retval;
 915         }
 916
 917         setattr_copy(dentry->d_inode, iattr);
 918         mark_inode_dirty(dentry->d_inode);
 919         return 0;
 920 }
 921
 922 /**
 923  * v9fs_stat2inode - populate an inode structure with mistat info
 924  * @stat: Plan 9 metadata (mistat) structure
 925  * @inode: inode to populate
 926  * @sb: superblock of filesystem
 927  *
 928  */
 929
 930 void
 931 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 932         struct super_block *sb)
 933 {
 934         char ext[32];
 935         char tag_name[14];
 936         unsigned int i_nlink;
 937         struct v9fs_session_info *v9ses = sb->s_fs_info;
 938
 939         inode->i_nlink = 1;
 940
 941         inode->i_atime.tv_sec = stat->atime;
 942         inode->i_mtime.tv_sec = stat->mtime;
 943         inode->i_ctime.tv_sec = stat->mtime;
 944
 945         inode->i_uid = v9ses->dfltuid;
 946         inode->i_gid = v9ses->dfltgid;
 947
 948         if (v9fs_proto_dotu(v9ses)) {
 949                 inode->i_uid = stat->n_uid;
 950                 inode->i_gid = stat->n_gid;
 951         }
 952         if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) {
 953                 if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) {
 954                         /*
 955                          * Hadlink support got added later to
 956                          * to the .u extension. So there can be
 957                          * server out there that doesn't support
 958                          * this even with .u extension. So check
 959                          * for non NULL stat->extension
 960                          */
 961                         strncpy(ext, stat->extension, sizeof(ext));
 962                         /* HARDLINKCOUNT %u */
 963                         sscanf(ext, "%13s %u", tag_name, &i_nlink);
 964                         if (!strncmp(tag_name, "HARDLINKCOUNT", 13))
 965                                 inode->i_nlink = i_nlink;
 966                 }
 967         }
 968         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 969         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 970                 char type = 0;
 971                 int major = -1;
 972                 int minor = -1;
 973
 974                 strncpy(ext, stat->extension, sizeof(ext));
 975                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 976                 switch (type) {
 977                 case 'c':
 978                         inode->i_mode &= ~S_IFBLK;
 979                         inode->i_mode |= S_IFCHR;
 980                         break;
 981                 case 'b':
 982                         break;
 983                 default:
 984                         P9_DPRINTK(P9_DEBUG_ERROR,
 985                                 "Unknown special type %c %s\n", type,
 986                                 stat->extension);
 987                 };
 988                 inode->i_rdev = MKDEV(major, minor);
 989                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 990         } else
 991                 inode->i_rdev = 0;
 992
 993         i_size_write(inode, stat->length);
 994
 995         /* not real number of blocks, but 512 byte ones ... */
 996         inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9;
 997 }
 998
 999 /**
1000  * v9fs_qid2ino - convert qid into inode number
1001  * @qid: qid to hash
1002  *
1003  * BUG: potential for inode number collisions?
1004  */
1005
1006 ino_t v9fs_qid2ino(struct p9_qid *qid)
1007 {
1008         u64 path = qid->path + 2;
1009         ino_t i = 0;
1010
1011         if (sizeof(ino_t) == sizeof(path))
1012                 memcpy(&i, &path, sizeof(ino_t));
1013         else
1014                 i = (ino_t) (path ^ (path >> 32));
1015
1016         return i;
1017 }
1018
1019 /**
1020  * v9fs_readlink - read a symlink's location (internal version)
1021  * @dentry: dentry for symlink
1022  * @buffer: buffer to load symlink location into
1023  * @buflen: length of buffer
1024  *
1025  */
1026
1027 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1028 {
1029         int retval;
1030
1031         struct v9fs_session_info *v9ses;
1032         struct p9_fid *fid;
1033         struct p9_wstat *st;
1034
1035         P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
1036         retval = -EPERM;
1037         v9ses = v9fs_inode2v9ses(dentry->d_inode);
1038         fid = v9fs_fid_lookup(dentry);
1039         if (IS_ERR(fid))
1040                 return PTR_ERR(fid);
1041
1042         if (!v9fs_proto_dotu(v9ses))
1043                 return -EBADF;
1044
1045         st = p9_client_stat(fid);
1046         if (IS_ERR(st))
1047                 return PTR_ERR(st);
1048
1049         if (!(st->mode & P9_DMSYMLINK)) {
1050                 retval = -EINVAL;
1051                 goto done;
1052         }
1053
1054         /* copy extension buffer into buffer */
1055         strncpy(buffer, st->extension, buflen);
1056
1057         P9_DPRINTK(P9_DEBUG_VFS,
1058                 "%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
1059
1060         retval = strnlen(buffer, buflen);
1061 done:
1062         p9stat_free(st);
1063         kfree(st);
1064         return retval;
1065 }
1066
1067 /**
1068  * v9fs_vfs_follow_link - follow a symlink path
1069  * @dentry: dentry for symlink
1070  * @nd: nameidata
1071  *
1072  */
1073
1074 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1075 {
1076         int len = 0;
1077         char *link = __getname();
1078
1079         P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
1080
1081         if (!link)
1082                 link = ERR_PTR(-ENOMEM);
1083         else {
1084                 len = v9fs_readlink(dentry, link, PATH_MAX);
1085
1086                 if (len < 0) {
1087                         __putname(link);
1088                         link = ERR_PTR(len);
1089                 } else
1090                         link[min(len, PATH_MAX-1)] = 0;
1091         }
1092         nd_set_link(nd, link);
1093
1094         return NULL;
1095 }
1096
1097 /**
1098  * v9fs_vfs_put_link - release a symlink path
1099  * @dentry: dentry for symlink
1100  * @nd: nameidata
1101  * @p: unused
1102  *
1103  */
1104
1105 void
1106 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1107 {
1108         char *s = nd_get_link(nd);
1109
1110         P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
1111                 IS_ERR(s) ? "<error>" : s);
1112         if (!IS_ERR(s))
1113                 __putname(s);
1114 }
1115
1116 /**
1117  * v9fs_vfs_mkspecial - create a special file
1118  * @dir: inode to create special file in
1119  * @dentry: dentry to create
1120  * @mode: mode to create special file
1121  * @extension: 9p2000.u format extension string representing special file
1122  *
1123  */
1124
1125 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1126         int mode, const char *extension)
1127 {
1128         u32 perm;
1129         struct v9fs_session_info *v9ses;
1130         struct p9_fid *fid;
1131
1132         v9ses = v9fs_inode2v9ses(dir);
1133         if (!v9fs_proto_dotu(v9ses)) {
1134                 P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1135                 return -EPERM;
1136         }
1137
1138         perm = unixmode2p9mode(v9ses, mode);
1139         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1140                                                                 P9_OREAD);
1141         if (IS_ERR(fid))
1142                 return PTR_ERR(fid);
1143
1144         p9_client_clunk(fid);
1145         return 0;
1146 }
1147
1148 /**
1149  * v9fs_vfs_symlink - helper function to create symlinks
1150  * @dir: directory inode containing symlink
1151  * @dentry: dentry for symlink
1152  * @symname: symlink data
1153  *
1154  * See Also: 9P2000.u RFC for more information
1155  *
1156  */
1157
1158 static int
1159 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1160 {
1161         P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1162                                         dentry->d_name.name, symname);
1163
1164         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1165 }
1166
1167 /**
1168  * v9fs_vfs_link - create a hardlink
1169  * @old_dentry: dentry for file to link to
1170  * @dir: inode destination for new link
1171  * @dentry: dentry for link
1172  *
1173  */
1174
1175 static int
1176 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1177               struct dentry *dentry)
1178 {
1179         int retval;
1180         struct p9_fid *oldfid;
1181         char *name;
1182
1183         P9_DPRINTK(P9_DEBUG_VFS,
1184                 " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1185                 old_dentry->d_name.name);
1186
1187         oldfid = v9fs_fid_clone(old_dentry);
1188         if (IS_ERR(oldfid))
1189                 return PTR_ERR(oldfid);
1190
1191         name = __getname();
1192         if (unlikely(!name)) {
1193                 retval = -ENOMEM;
1194                 goto clunk_fid;
1195         }
1196
1197         sprintf(name, "%d\n", oldfid->fid);
1198         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1199         __putname(name);
1200
1201 clunk_fid:
1202         p9_client_clunk(oldfid);
1203         return retval;
1204 }
1205
1206 /**
1207  * v9fs_vfs_mknod - create a special file
1208  * @dir: inode destination for new link
1209  * @dentry: dentry for file
1210  * @mode: mode for creation
1211  * @rdev: device associated with special file
1212  *
1213  */
1214
1215 static int
1216 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1217 {
1218         int retval;
1219         char *name;
1220
1221         P9_DPRINTK(P9_DEBUG_VFS,
1222                 " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1223                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1224
1225         if (!new_valid_dev(rdev))
1226                 return -EINVAL;
1227
1228         name = __getname();
1229         if (!name)
1230                 return -ENOMEM;
1231         /* build extension */
1232         if (S_ISBLK(mode))
1233                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1234         else if (S_ISCHR(mode))
1235                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1236         else if (S_ISFIFO(mode))
1237                 *name = 0;
1238         else if (S_ISSOCK(mode))
1239                 *name = 0;
1240         else {
1241                 __putname(name);
1242                 return -EINVAL;
1243         }
1244
1245         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1246         __putname(name);
1247
1248         return retval;
1249 }
1250
1251 static const struct inode_operations v9fs_dir_inode_operations_dotu = {
1252         .create = v9fs_vfs_create,
1253         .lookup = v9fs_vfs_lookup,
1254         .symlink = v9fs_vfs_symlink,
1255         .link = v9fs_vfs_link,
1256         .unlink = v9fs_vfs_unlink,
1257         .mkdir = v9fs_vfs_mkdir,
1258         .rmdir = v9fs_vfs_rmdir,
1259         .mknod = v9fs_vfs_mknod,
1260         .rename = v9fs_vfs_rename,
1261         .getattr = v9fs_vfs_getattr,
1262         .setattr = v9fs_vfs_setattr,
1263 };
1264
1265 static const struct inode_operations v9fs_dir_inode_operations = {
1266         .create = v9fs_vfs_create,
1267         .lookup = v9fs_vfs_lookup,
1268         .unlink = v9fs_vfs_unlink,
1269         .mkdir = v9fs_vfs_mkdir,
1270         .rmdir = v9fs_vfs_rmdir,
1271         .mknod = v9fs_vfs_mknod,
1272         .rename = v9fs_vfs_rename,
1273         .getattr = v9fs_vfs_getattr,
1274         .setattr = v9fs_vfs_setattr,
1275 };
1276
1277 static const struct inode_operations v9fs_file_inode_operations = {
1278         .getattr = v9fs_vfs_getattr,
1279         .setattr = v9fs_vfs_setattr,
1280 };
1281
1282 static const struct inode_operations v9fs_symlink_inode_operations = {
1283         .readlink = generic_readlink,
1284         .follow_link = v9fs_vfs_follow_link,
1285         .put_link = v9fs_vfs_put_link,
1286         .getattr = v9fs_vfs_getattr,
1287         .setattr = v9fs_vfs_setattr,
1288 };
1289