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 <net/9p/9p.h>
  38 #include <net/9p/client.h>
  39
  40 #include "v9fs.h"
  41 #include "v9fs_vfs.h"
  42 #include "fid.h"
  43
  44 static const struct inode_operations v9fs_dir_inode_operations;
  45 static const struct inode_operations v9fs_dir_inode_operations_ext;
  46 static const struct inode_operations v9fs_file_inode_operations;
  47 static const struct inode_operations v9fs_symlink_inode_operations;
  48
  49 /**
  50  * unixmode2p9mode - convert unix mode bits to plan 9
  51  * @v9ses: v9fs session information
  52  * @mode: mode to convert
  53  *
  54  */
  55
  56 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
  57 {
  58         int res;
  59         res = mode & 0777;
  60         if (S_ISDIR(mode))
  61                 res |= P9_DMDIR;
  62         if (v9fs_extended(v9ses)) {
  63                 if (S_ISLNK(mode))
  64                         res |= P9_DMSYMLINK;
  65                 if (v9ses->nodev == 0) {
  66                         if (S_ISSOCK(mode))
  67                                 res |= P9_DMSOCKET;
  68                         if (S_ISFIFO(mode))
  69                                 res |= P9_DMNAMEDPIPE;
  70                         if (S_ISBLK(mode))
  71                                 res |= P9_DMDEVICE;
  72                         if (S_ISCHR(mode))
  73                                 res |= P9_DMDEVICE;
  74                 }
  75
  76                 if ((mode & S_ISUID) == S_ISUID)
  77                         res |= P9_DMSETUID;
  78                 if ((mode & S_ISGID) == S_ISGID)
  79                         res |= P9_DMSETGID;
  80                 if ((mode & S_ISVTX) == S_ISVTX)
  81                         res |= P9_DMSETVTX;
  82                 if ((mode & P9_DMLINK))
  83                         res |= P9_DMLINK;
  84         }
  85
  86         return res;
  87 }
  88
  89 /**
  90  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  91  * @v9ses: v9fs session information
  92  * @mode: mode to convert
  93  *
  94  */
  95
  96 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
  97 {
  98         int res;
  99
 100         res = mode & 0777;
 101
 102         if ((mode & P9_DMDIR) == P9_DMDIR)
 103                 res |= S_IFDIR;
 104         else if ((mode & P9_DMSYMLINK) && (v9fs_extended(v9ses)))
 105                 res |= S_IFLNK;
 106         else if ((mode & P9_DMSOCKET) && (v9fs_extended(v9ses))
 107                  && (v9ses->nodev == 0))
 108                 res |= S_IFSOCK;
 109         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_extended(v9ses))
 110                  && (v9ses->nodev == 0))
 111                 res |= S_IFIFO;
 112         else if ((mode & P9_DMDEVICE) && (v9fs_extended(v9ses))
 113                  && (v9ses->nodev == 0))
 114                 res |= S_IFBLK;
 115         else
 116                 res |= S_IFREG;
 117
 118         if (v9fs_extended(v9ses)) {
 119                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
 120                         res |= S_ISUID;
 121
 122                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
 123                         res |= S_ISGID;
 124
 125                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 126                         res |= S_ISVTX;
 127         }
 128
 129         return res;
 130 }
 131
 132 /**
 133  * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits
 134  * @uflags: flags to convert
 135  * @extended: if .u extensions are active
 136  */
 137
 138 int v9fs_uflags2omode(int uflags, int extended)
 139 {
 140         int ret;
 141
 142         ret = 0;
 143         switch (uflags&3) {
 144         default:
 145         case O_RDONLY:
 146                 ret = P9_OREAD;
 147                 break;
 148
 149         case O_WRONLY:
 150                 ret = P9_OWRITE;
 151                 break;
 152
 153         case O_RDWR:
 154                 ret = P9_ORDWR;
 155                 break;
 156         }
 157
 158         if (uflags & O_TRUNC)
 159                 ret |= P9_OTRUNC;
 160
 161         if (extended) {
 162                 if (uflags & O_EXCL)
 163                         ret |= P9_OEXCL;
 164
 165                 if (uflags & O_APPEND)
 166                         ret |= P9_OAPPEND;
 167         }
 168
 169         return ret;
 170 }
 171
 172 /**
 173  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 174  * @wstat: structure to initialize
 175  *
 176  */
 177
 178 static void
 179 v9fs_blank_wstat(struct p9_wstat *wstat)
 180 {
 181         wstat->type = ~0;
 182         wstat->dev = ~0;
 183         wstat->qid.type = ~0;
 184         wstat->qid.version = ~0;
 185         *((long long *)&wstat->qid.path) = ~0;
 186         wstat->mode = ~0;
 187         wstat->atime = ~0;
 188         wstat->mtime = ~0;
 189         wstat->length = ~0;
 190         wstat->name = NULL;
 191         wstat->uid = NULL;
 192         wstat->gid = NULL;
 193         wstat->muid = NULL;
 194         wstat->n_uid = ~0;
 195         wstat->n_gid = ~0;
 196         wstat->n_muid = ~0;
 197         wstat->extension = NULL;
 198 }
 199
 200 /**
 201  * v9fs_get_inode - helper function to setup an inode
 202  * @sb: superblock
 203  * @mode: mode to setup inode with
 204  *
 205  */
 206
 207 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 208 {
 209         int err;
 210         struct inode *inode;
 211         struct v9fs_session_info *v9ses = sb->s_fs_info;
 212
 213         P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 214
 215         inode = new_inode(sb);
 216         if (!inode) {
 217                 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
 218                 return ERR_PTR(-ENOMEM);
 219         }
 220
 221         inode->i_mode = mode;
 222         inode->i_uid = current_fsuid();
 223         inode->i_gid = current_fsgid();
 224         inode->i_blocks = 0;
 225         inode->i_rdev = 0;
 226         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 227         inode->i_mapping->a_ops = &v9fs_addr_operations;
 228
 229         switch (mode & S_IFMT) {
 230         case S_IFIFO:
 231         case S_IFBLK:
 232         case S_IFCHR:
 233         case S_IFSOCK:
 234                 if (!v9fs_extended(v9ses)) {
 235                         P9_DPRINTK(P9_DEBUG_ERROR,
 236                                    "special files without extended mode\n");
 237                         err = -EINVAL;
 238                         goto error;
 239                 }
 240                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 241                 break;
 242         case S_IFREG:
 243                 inode->i_op = &v9fs_file_inode_operations;
 244                 inode->i_fop = &v9fs_file_operations;
 245                 break;
 246         case S_IFLNK:
 247                 if (!v9fs_extended(v9ses)) {
 248                         P9_DPRINTK(P9_DEBUG_ERROR,
 249                                    "extended modes used w/o 9P2000.u\n");
 250                         err = -EINVAL;
 251                         goto error;
 252                 }
 253                 inode->i_op = &v9fs_symlink_inode_operations;
 254                 break;
 255         case S_IFDIR:
 256                 inc_nlink(inode);
 257                 if (v9fs_extended(v9ses))
 258                         inode->i_op = &v9fs_dir_inode_operations_ext;
 259                 else
 260                         inode->i_op = &v9fs_dir_inode_operations;
 261                 inode->i_fop = &v9fs_dir_operations;
 262                 break;
 263         default:
 264                 P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
 265                            mode, mode & S_IFMT);
 266                 err = -EINVAL;
 267                 goto error;
 268         }
 269
 270         return inode;
 271
 272 error:
 273         iput(inode);
 274         return ERR_PTR(err);
 275 }
 276
 277 /*
 278 static struct v9fs_fid*
 279 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 280 {
 281         int err;
 282         int nfid;
 283         struct v9fs_fid *ret;
 284         struct v9fs_fcall *fcall;
 285
 286         nfid = v9fs_get_idpool(&v9ses->fidpool);
 287         if (nfid < 0) {
 288                 eprintk(KERN_WARNING, "no free fids available\n");
 289                 return ERR_PTR(-ENOSPC);
 290         }
 291
 292         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 293                 &fcall);
 294
 295         if (err < 0) {
 296                 if (fcall && fcall->id == RWALK)
 297                         goto clunk_fid;
 298
 299                 PRINT_FCALL_ERROR("walk error", fcall);
 300                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 301                 goto error;
 302         }
 303
 304         kfree(fcall);
 305         fcall = NULL;
 306         ret = v9fs_fid_create(v9ses, nfid);
 307         if (!ret) {
 308                 err = -ENOMEM;
 309                 goto clunk_fid;
 310         }
 311
 312         err = v9fs_fid_insert(ret, dentry);
 313         if (err < 0) {
 314                 v9fs_fid_destroy(ret);
 315                 goto clunk_fid;
 316         }
 317
 318         return ret;
 319
 320 clunk_fid:
 321         v9fs_t_clunk(v9ses, nfid);
 322
 323 error:
 324         kfree(fcall);
 325         return ERR_PTR(err);
 326 }
 327 */
 328
 329 /**
 330  * v9fs_inode_from_fid - populate an inode by issuing a attribute request
 331  * @v9ses: session information
 332  * @fid: fid to issue attribute request for
 333  * @sb: superblock on which to create inode
 334  *
 335  */
 336
 337 static struct inode *
 338 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 339         struct super_block *sb)
 340 {
 341         int err, umode;
 342         struct inode *ret;
 343         struct p9_wstat *st;
 344
 345         ret = NULL;
 346         st = p9_client_stat(fid);
 347         if (IS_ERR(st))
 348                 return ERR_CAST(st);
 349
 350         umode = p9mode2unixmode(v9ses, st->mode);
 351         ret = v9fs_get_inode(sb, umode);
 352         if (IS_ERR(ret)) {
 353                 err = PTR_ERR(ret);
 354                 goto error;
 355         }
 356
 357         v9fs_stat2inode(st, ret, sb);
 358         ret->i_ino = v9fs_qid2ino(&st->qid);
 359         p9stat_free(st);
 360         kfree(st);
 361         return ret;
 362
 363 error:
 364         p9stat_free(st);
 365         kfree(st);
 366         return ERR_PTR(err);
 367 }
 368
 369 /**
 370  * v9fs_remove - helper function to remove files and directories
 371  * @dir: directory inode that is being deleted
 372  * @file:  dentry that is being deleted
 373  * @rmdir: removing a directory
 374  *
 375  */
 376
 377 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 378 {
 379         struct inode *file_inode;
 380         struct v9fs_session_info *v9ses;
 381         struct p9_fid *v9fid;
 382
 383         P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 384                 rmdir);
 385
 386         file_inode = file->d_inode;
 387         v9ses = v9fs_inode2v9ses(file_inode);
 388         v9fid = v9fs_fid_clone(file);
 389         if (IS_ERR(v9fid))
 390                 return PTR_ERR(v9fid);
 391
 392         return p9_client_remove(v9fid);
 393 }
 394
 395 static int
 396 v9fs_open_created(struct inode *inode, struct file *file)
 397 {
 398         return 0;
 399 }
 400
 401
 402 /**
 403  * v9fs_create - Create a file
 404  * @v9ses: session information
 405  * @dir: directory that dentry is being created in
 406  * @dentry:  dentry that is being created
 407  * @extension: 9p2000.u extension string to support devices, etc.
 408  * @perm: create permissions
 409  * @mode: open mode
 410  *
 411  */
 412 static struct p9_fid *
 413 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 414                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 415 {
 416         int err;
 417         char *name;
 418         struct p9_fid *dfid, *ofid, *fid;
 419         struct inode *inode;
 420
 421         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 422
 423         err = 0;
 424         ofid = NULL;
 425         fid = NULL;
 426         name = (char *) dentry->d_name.name;
 427         dfid = v9fs_fid_clone(dentry->d_parent);
 428         if (IS_ERR(dfid)) {
 429                 err = PTR_ERR(dfid);
 430                 P9_DPRINTK(P9_DEBUG_VFS, "fid clone failed %d\n", err);
 431                 dfid = NULL;
 432                 goto error;
 433         }
 434
 435         /* clone a fid to use for creation */
 436         ofid = p9_client_walk(dfid, 0, NULL, 1);
 437         if (IS_ERR(ofid)) {
 438                 err = PTR_ERR(ofid);
 439                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 440                 ofid = NULL;
 441                 goto error;
 442         }
 443
 444         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 445         if (err < 0) {
 446                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err);
 447                 goto error;
 448         }
 449
 450         /* now walk from the parent so we can get unopened fid */
 451         fid = p9_client_walk(dfid, 1, &name, 0);
 452         if (IS_ERR(fid)) {
 453                 err = PTR_ERR(fid);
 454                 P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err);
 455                 fid = NULL;
 456                 goto error;
 457         } else
 458                 dfid = NULL;
 459
 460         /* instantiate inode and assign the unopened fid to the dentry */
 461         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 462         if (IS_ERR(inode)) {
 463                 err = PTR_ERR(inode);
 464                 P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err);
 465                 goto error;
 466         }
 467
 468         if (v9ses->cache)
 469                 dentry->d_op = &v9fs_cached_dentry_operations;
 470         else
 471                 dentry->d_op = &v9fs_dentry_operations;
 472
 473         d_instantiate(dentry, inode);
 474         err = v9fs_fid_add(dentry, fid);
 475         if (err < 0)
 476                 goto error;
 477
 478         return ofid;
 479
 480 error:
 481         if (dfid)
 482                 p9_client_clunk(dfid);
 483
 484         if (ofid)
 485                 p9_client_clunk(ofid);
 486
 487         if (fid)
 488                 p9_client_clunk(fid);
 489
 490         return ERR_PTR(err);
 491 }
 492
 493 /**
 494  * v9fs_vfs_create - VFS hook to create files
 495  * @dir: directory inode that is being created
 496  * @dentry:  dentry that is being deleted
 497  * @mode: create permissions
 498  * @nd: path information
 499  *
 500  */
 501
 502 static int
 503 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 504                 struct nameidata *nd)
 505 {
 506         int err;
 507         u32 perm;
 508         int flags;
 509         struct v9fs_session_info *v9ses;
 510         struct p9_fid *fid;
 511         struct file *filp;
 512
 513         err = 0;
 514         fid = NULL;
 515         v9ses = v9fs_inode2v9ses(dir);
 516         perm = unixmode2p9mode(v9ses, mode);
 517         if (nd && nd->flags & LOOKUP_OPEN)
 518                 flags = nd->intent.open.flags - 1;
 519         else
 520                 flags = O_RDWR;
 521
 522         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 523                                 v9fs_uflags2omode(flags, v9fs_extended(v9ses)));
 524         if (IS_ERR(fid)) {
 525                 err = PTR_ERR(fid);
 526                 fid = NULL;
 527                 goto error;
 528         }
 529
 530         /* if we are opening a file, assign the open fid to the file */
 531         if (nd && nd->flags & LOOKUP_OPEN) {
 532                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 533                 if (IS_ERR(filp)) {
 534                         err = PTR_ERR(filp);
 535                         goto error;
 536                 }
 537
 538                 filp->private_data = fid;
 539         } else
 540                 p9_client_clunk(fid);
 541
 542         return 0;
 543
 544 error:
 545         if (fid)
 546                 p9_client_clunk(fid);
 547
 548         return err;
 549 }
 550
 551 /**
 552  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 553  * @dir:  inode that is being unlinked
 554  * @dentry: dentry that is being unlinked
 555  * @mode: mode for new directory
 556  *
 557  */
 558
 559 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 560 {
 561         int err;
 562         u32 perm;
 563         struct v9fs_session_info *v9ses;
 564         struct p9_fid *fid;
 565
 566         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 567         err = 0;
 568         v9ses = v9fs_inode2v9ses(dir);
 569         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 570         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 571         if (IS_ERR(fid)) {
 572                 err = PTR_ERR(fid);
 573                 fid = NULL;
 574         }
 575
 576         if (fid)
 577                 p9_client_clunk(fid);
 578
 579         return err;
 580 }
 581
 582 /**
 583  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 584  * @dir:  inode that is being walked from
 585  * @dentry: dentry that is being walked to?
 586  * @nameidata: path data
 587  *
 588  */
 589
 590 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 591                                       struct nameidata *nameidata)
 592 {
 593         struct super_block *sb;
 594         struct v9fs_session_info *v9ses;
 595         struct p9_fid *dfid, *fid;
 596         struct inode *inode;
 597         char *name;
 598         int result = 0;
 599
 600         P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 601                 dir, dentry->d_name.name, dentry, nameidata);
 602
 603         sb = dir->i_sb;
 604         v9ses = v9fs_inode2v9ses(dir);
 605         dfid = v9fs_fid_lookup(dentry->d_parent);
 606         if (IS_ERR(dfid))
 607                 return ERR_CAST(dfid);
 608
 609         name = (char *) dentry->d_name.name;
 610         fid = p9_client_walk(dfid, 1, &name, 1);
 611         if (IS_ERR(fid)) {
 612                 result = PTR_ERR(fid);
 613                 if (result == -ENOENT) {
 614                         d_add(dentry, NULL);
 615                         return NULL;
 616                 }
 617
 618                 return ERR_PTR(result);
 619         }
 620
 621         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 622         if (IS_ERR(inode)) {
 623                 result = PTR_ERR(inode);
 624                 inode = NULL;
 625                 goto error;
 626         }
 627
 628         result = v9fs_fid_add(dentry, fid);
 629         if (result < 0)
 630                 goto error;
 631
 632         if ((fid->qid.version) && (v9ses->cache))
 633                 dentry->d_op = &v9fs_cached_dentry_operations;
 634         else
 635                 dentry->d_op = &v9fs_dentry_operations;
 636
 637         d_add(dentry, inode);
 638         return NULL;
 639
 640 error:
 641         p9_client_clunk(fid);
 642
 643         return ERR_PTR(result);
 644 }
 645
 646 /**
 647  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 648  * @i:  inode that is being unlinked
 649  * @d: dentry that is being unlinked
 650  *
 651  */
 652
 653 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 654 {
 655         return v9fs_remove(i, d, 0);
 656 }
 657
 658 /**
 659  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 660  * @i:  inode that is being unlinked
 661  * @d: dentry that is being unlinked
 662  *
 663  */
 664
 665 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 666 {
 667         return v9fs_remove(i, d, 1);
 668 }
 669
 670 /**
 671  * v9fs_vfs_rename - VFS hook to rename an inode
 672  * @old_dir:  old dir inode
 673  * @old_dentry: old dentry
 674  * @new_dir: new dir inode
 675  * @new_dentry: new dentry
 676  *
 677  */
 678
 679 static int
 680 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 681                 struct inode *new_dir, struct dentry *new_dentry)
 682 {
 683         struct inode *old_inode;
 684         struct v9fs_session_info *v9ses;
 685         struct p9_fid *oldfid;
 686         struct p9_fid *olddirfid;
 687         struct p9_fid *newdirfid;
 688         struct p9_wstat wstat;
 689         int retval;
 690
 691         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 692         retval = 0;
 693         old_inode = old_dentry->d_inode;
 694         v9ses = v9fs_inode2v9ses(old_inode);
 695         oldfid = v9fs_fid_lookup(old_dentry);
 696         if (IS_ERR(oldfid))
 697                 return PTR_ERR(oldfid);
 698
 699         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 700         if (IS_ERR(olddirfid)) {
 701                 retval = PTR_ERR(olddirfid);
 702                 goto done;
 703         }
 704
 705         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 706         if (IS_ERR(newdirfid)) {
 707                 retval = PTR_ERR(newdirfid);
 708                 goto clunk_olddir;
 709         }
 710
 711         /* 9P can only handle file rename in the same directory */
 712         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 713                 P9_DPRINTK(P9_DEBUG_ERROR,
 714                                 "old dir and new dir are different\n");
 715                 retval = -EXDEV;
 716                 goto clunk_newdir;
 717         }
 718
 719         v9fs_blank_wstat(&wstat);
 720         wstat.muid = v9ses->uname;
 721         wstat.name = (char *) new_dentry->d_name.name;
 722         retval = p9_client_wstat(oldfid, &wstat);
 723
 724 clunk_newdir:
 725         p9_client_clunk(newdirfid);
 726
 727 clunk_olddir:
 728         p9_client_clunk(olddirfid);
 729
 730 done:
 731         return retval;
 732 }
 733
 734 /**
 735  * v9fs_vfs_getattr - retrieve file metadata
 736  * @mnt: mount information
 737  * @dentry: file to get attributes on
 738  * @stat: metadata structure to populate
 739  *
 740  */
 741
 742 static int
 743 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 744                  struct kstat *stat)
 745 {
 746         int err;
 747         struct v9fs_session_info *v9ses;
 748         struct p9_fid *fid;
 749         struct p9_wstat *st;
 750
 751         P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 752         err = -EPERM;
 753         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 754         if (v9ses->cache == CACHE_LOOSE)
 755                 return simple_getattr(mnt, dentry, stat);
 756
 757         fid = v9fs_fid_lookup(dentry);
 758         if (IS_ERR(fid))
 759                 return PTR_ERR(fid);
 760
 761         st = p9_client_stat(fid);
 762         if (IS_ERR(st))
 763                 return PTR_ERR(st);
 764
 765         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
 766                 generic_fillattr(dentry->d_inode, stat);
 767
 768         kfree(st);
 769         return 0;
 770 }
 771
 772 /**
 773  * v9fs_vfs_setattr - set file metadata
 774  * @dentry: file whose metadata to set
 775  * @iattr: metadata assignment structure
 776  *
 777  */
 778
 779 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 780 {
 781         int retval;
 782         struct v9fs_session_info *v9ses;
 783         struct p9_fid *fid;
 784         struct p9_wstat wstat;
 785
 786         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 787         retval = -EPERM;
 788         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 789         fid = v9fs_fid_lookup(dentry);
 790         if(IS_ERR(fid))
 791                 return PTR_ERR(fid);
 792
 793         v9fs_blank_wstat(&wstat);
 794         if (iattr->ia_valid & ATTR_MODE)
 795                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 796
 797         if (iattr->ia_valid & ATTR_MTIME)
 798                 wstat.mtime = iattr->ia_mtime.tv_sec;
 799
 800         if (iattr->ia_valid & ATTR_ATIME)
 801                 wstat.atime = iattr->ia_atime.tv_sec;
 802
 803         if (iattr->ia_valid & ATTR_SIZE)
 804                 wstat.length = iattr->ia_size;
 805
 806         if (v9fs_extended(v9ses)) {
 807                 if (iattr->ia_valid & ATTR_UID)
 808                         wstat.n_uid = iattr->ia_uid;
 809
 810                 if (iattr->ia_valid & ATTR_GID)
 811                         wstat.n_gid = iattr->ia_gid;
 812         }
 813
 814         retval = p9_client_wstat(fid, &wstat);
 815         if (retval >= 0)
 816                 retval = inode_setattr(dentry->d_inode, iattr);
 817
 818         return retval;
 819 }
 820
 821 /**
 822  * v9fs_stat2inode - populate an inode structure with mistat info
 823  * @stat: Plan 9 metadata (mistat) structure
 824  * @inode: inode to populate
 825  * @sb: superblock of filesystem
 826  *
 827  */
 828
 829 void
 830 v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode,
 831         struct super_block *sb)
 832 {
 833         char ext[32];
 834         struct v9fs_session_info *v9ses = sb->s_fs_info;
 835
 836         inode->i_nlink = 1;
 837
 838         inode->i_atime.tv_sec = stat->atime;
 839         inode->i_mtime.tv_sec = stat->mtime;
 840         inode->i_ctime.tv_sec = stat->mtime;
 841
 842         inode->i_uid = v9ses->dfltuid;
 843         inode->i_gid = v9ses->dfltgid;
 844
 845         if (v9fs_extended(v9ses)) {
 846                 inode->i_uid = stat->n_uid;
 847                 inode->i_gid = stat->n_gid;
 848         }
 849
 850         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 851         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 852                 char type = 0;
 853                 int major = -1;
 854                 int minor = -1;
 855
 856                 strncpy(ext, stat->extension, sizeof(ext));
 857                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 858                 switch (type) {
 859                 case 'c':
 860                         inode->i_mode &= ~S_IFBLK;
 861                         inode->i_mode |= S_IFCHR;
 862                         break;
 863                 case 'b':
 864                         break;
 865                 default:
 866                         P9_DPRINTK(P9_DEBUG_ERROR,
 867                                 "Unknown special type %c %s\n", type,
 868                                 stat->extension);
 869                 };
 870                 inode->i_rdev = MKDEV(major, minor);
 871                 init_special_inode(inode, inode->i_mode, inode->i_rdev);
 872         } else
 873                 inode->i_rdev = 0;
 874
 875         inode->i_size = stat->length;
 876
 877         /* not real number of blocks, but 512 byte ones ... */
 878         inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
 879 }
 880
 881 /**
 882  * v9fs_qid2ino - convert qid into inode number
 883  * @qid: qid to hash
 884  *
 885  * BUG: potential for inode number collisions?
 886  */
 887
 888 ino_t v9fs_qid2ino(struct p9_qid *qid)
 889 {
 890         u64 path = qid->path + 2;
 891         ino_t i = 0;
 892
 893         if (sizeof(ino_t) == sizeof(path))
 894                 memcpy(&i, &path, sizeof(ino_t));
 895         else
 896                 i = (ino_t) (path ^ (path >> 32));
 897
 898         return i;
 899 }
 900
 901 /**
 902  * v9fs_readlink - read a symlink's location (internal version)
 903  * @dentry: dentry for symlink
 904  * @buffer: buffer to load symlink location into
 905  * @buflen: length of buffer
 906  *
 907  */
 908
 909 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 910 {
 911         int retval;
 912
 913         struct v9fs_session_info *v9ses;
 914         struct p9_fid *fid;
 915         struct p9_wstat *st;
 916
 917         P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
 918         retval = -EPERM;
 919         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 920         fid = v9fs_fid_lookup(dentry);
 921         if (IS_ERR(fid))
 922                 return PTR_ERR(fid);
 923
 924         if (!v9fs_extended(v9ses))
 925                 return -EBADF;
 926
 927         st = p9_client_stat(fid);
 928         if (IS_ERR(st))
 929                 return PTR_ERR(st);
 930
 931         if (!(st->mode & P9_DMSYMLINK)) {
 932                 retval = -EINVAL;
 933                 goto done;
 934         }
 935
 936         /* copy extension buffer into buffer */
 937         strncpy(buffer, st->extension, buflen);
 938
 939         P9_DPRINTK(P9_DEBUG_VFS,
 940                 "%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer);
 941
 942         retval = buflen;
 943
 944 done:
 945         kfree(st);
 946         return retval;
 947 }
 948
 949 /**
 950  * v9fs_vfs_readlink - read a symlink's location
 951  * @dentry: dentry for symlink
 952  * @buffer: buffer to load symlink location into
 953  * @buflen: length of buffer
 954  *
 955  */
 956
 957 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
 958                              int buflen)
 959 {
 960         int retval;
 961         int ret;
 962         char *link = __getname();
 963
 964         if (unlikely(!link))
 965                 return -ENOMEM;
 966
 967         if (buflen > PATH_MAX)
 968                 buflen = PATH_MAX;
 969
 970         P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name,
 971                                                                         dentry);
 972
 973         retval = v9fs_readlink(dentry, link, buflen);
 974
 975         if (retval > 0) {
 976                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
 977                         P9_DPRINTK(P9_DEBUG_ERROR,
 978                                         "problem copying to user: %d\n", ret);
 979                         retval = ret;
 980                 }
 981         }
 982
 983         __putname(link);
 984         return retval;
 985 }
 986
 987 /**
 988  * v9fs_vfs_follow_link - follow a symlink path
 989  * @dentry: dentry for symlink
 990  * @nd: nameidata
 991  *
 992  */
 993
 994 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 995 {
 996         int len = 0;
 997         char *link = __getname();
 998
 999         P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
1000
1001         if (!link)
1002                 link = ERR_PTR(-ENOMEM);
1003         else {
1004                 len = v9fs_readlink(dentry, link, PATH_MAX);
1005
1006                 if (len < 0) {
1007                         __putname(link);
1008                         link = ERR_PTR(len);
1009                 } else
1010                         link[len] = 0;
1011         }
1012         nd_set_link(nd, link);
1013
1014         return NULL;
1015 }
1016
1017 /**
1018  * v9fs_vfs_put_link - release a symlink path
1019  * @dentry: dentry for symlink
1020  * @nd: nameidata
1021  * @p: unused
1022  *
1023  */
1024
1025 static void
1026 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1027 {
1028         char *s = nd_get_link(nd);
1029
1030         P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name,
1031                 IS_ERR(s) ? "<error>" : s);
1032         if (!IS_ERR(s))
1033                 __putname(s);
1034 }
1035
1036 /**
1037  * v9fs_vfs_mkspecial - create a special file
1038  * @dir: inode to create special file in
1039  * @dentry: dentry to create
1040  * @mode: mode to create special file
1041  * @extension: 9p2000.u format extension string representing special file
1042  *
1043  */
1044
1045 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1046         int mode, const char *extension)
1047 {
1048         u32 perm;
1049         struct v9fs_session_info *v9ses;
1050         struct p9_fid *fid;
1051
1052         v9ses = v9fs_inode2v9ses(dir);
1053         if (!v9fs_extended(v9ses)) {
1054                 P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1055                 return -EPERM;
1056         }
1057
1058         perm = unixmode2p9mode(v9ses, mode);
1059         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1060                                                                 P9_OREAD);
1061         if (IS_ERR(fid))
1062                 return PTR_ERR(fid);
1063
1064         p9_client_clunk(fid);
1065         return 0;
1066 }
1067
1068 /**
1069  * v9fs_vfs_symlink - helper function to create symlinks
1070  * @dir: directory inode containing symlink
1071  * @dentry: dentry for symlink
1072  * @symname: symlink data
1073  *
1074  * See Also: 9P2000.u RFC for more information
1075  *
1076  */
1077
1078 static int
1079 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1080 {
1081         P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1082                                         dentry->d_name.name, symname);
1083
1084         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1085 }
1086
1087 /**
1088  * v9fs_vfs_link - create a hardlink
1089  * @old_dentry: dentry for file to link to
1090  * @dir: inode destination for new link
1091  * @dentry: dentry for link
1092  *
1093  */
1094
1095 static int
1096 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1097               struct dentry *dentry)
1098 {
1099         int retval;
1100         struct p9_fid *oldfid;
1101         char *name;
1102
1103         P9_DPRINTK(P9_DEBUG_VFS,
1104                 " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1105                 old_dentry->d_name.name);
1106
1107         oldfid = v9fs_fid_clone(old_dentry);
1108         if (IS_ERR(oldfid))
1109                 return PTR_ERR(oldfid);
1110
1111         name = __getname();
1112         if (unlikely(!name)) {
1113                 retval = -ENOMEM;
1114                 goto clunk_fid;
1115         }
1116
1117         sprintf(name, "%d\n", oldfid->fid);
1118         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1119         __putname(name);
1120
1121 clunk_fid:
1122         p9_client_clunk(oldfid);
1123         return retval;
1124 }
1125
1126 /**
1127  * v9fs_vfs_mknod - create a special file
1128  * @dir: inode destination for new link
1129  * @dentry: dentry for file
1130  * @mode: mode for creation
1131  * @rdev: device associated with special file
1132  *
1133  */
1134
1135 static int
1136 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1137 {
1138         int retval;
1139         char *name;
1140
1141         P9_DPRINTK(P9_DEBUG_VFS,
1142                 " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1143                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1144
1145         if (!new_valid_dev(rdev))
1146                 return -EINVAL;
1147
1148         name = __getname();
1149         if (!name)
1150                 return -ENOMEM;
1151         /* build extension */
1152         if (S_ISBLK(mode))
1153                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1154         else if (S_ISCHR(mode))
1155                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1156         else if (S_ISFIFO(mode))
1157                 *name = 0;
1158         else {
1159                 __putname(name);
1160                 return -EINVAL;
1161         }
1162
1163         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1164         __putname(name);
1165
1166         return retval;
1167 }
1168
1169 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1170         .create = v9fs_vfs_create,
1171         .lookup = v9fs_vfs_lookup,
1172         .symlink = v9fs_vfs_symlink,
1173         .link = v9fs_vfs_link,
1174         .unlink = v9fs_vfs_unlink,
1175         .mkdir = v9fs_vfs_mkdir,
1176         .rmdir = v9fs_vfs_rmdir,
1177         .mknod = v9fs_vfs_mknod,
1178         .rename = v9fs_vfs_rename,
1179         .readlink = v9fs_vfs_readlink,
1180         .getattr = v9fs_vfs_getattr,
1181         .setattr = v9fs_vfs_setattr,
1182 };
1183
1184 static const struct inode_operations v9fs_dir_inode_operations = {
1185         .create = v9fs_vfs_create,
1186         .lookup = v9fs_vfs_lookup,
1187         .unlink = v9fs_vfs_unlink,
1188         .mkdir = v9fs_vfs_mkdir,
1189         .rmdir = v9fs_vfs_rmdir,
1190         .mknod = v9fs_vfs_mknod,
1191         .rename = v9fs_vfs_rename,
1192         .getattr = v9fs_vfs_getattr,
1193         .setattr = v9fs_vfs_setattr,
1194 };
1195
1196 static const struct inode_operations v9fs_file_inode_operations = {
1197         .getattr = v9fs_vfs_getattr,
1198         .setattr = v9fs_vfs_setattr,
1199 };
1200
1201 static const struct inode_operations v9fs_symlink_inode_operations = {
1202         .readlink = v9fs_vfs_readlink,
1203         .follow_link = v9fs_vfs_follow_link,
1204         .put_link = v9fs_vfs_put_link,
1205         .getattr = v9fs_vfs_getattr,
1206         .setattr = v9fs_vfs_setattr,
1207 };