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 & P9_DMLINK))
  81                         res |= P9_DMLINK;
  82         }
  83
  84         return res;
  85 }
  86
  87 /**
  88  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  89  * @v9ses: v9fs session information
  90  * @mode: mode to convert
  91  *
  92  */
  93
  94 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
  95 {
  96         int res;
  97
  98         res = mode & 0777;
  99
 100         if ((mode & P9_DMDIR) == P9_DMDIR)
 101                 res |= S_IFDIR;
 102         else if ((mode & P9_DMSYMLINK) && (v9fs_extended(v9ses)))
 103                 res |= S_IFLNK;
 104         else if ((mode & P9_DMSOCKET) && (v9fs_extended(v9ses))
 105                  && (v9ses->nodev == 0))
 106                 res |= S_IFSOCK;
 107         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_extended(v9ses))
 108                  && (v9ses->nodev == 0))
 109                 res |= S_IFIFO;
 110         else if ((mode & P9_DMDEVICE) && (v9fs_extended(v9ses))
 111                  && (v9ses->nodev == 0))
 112                 res |= S_IFBLK;
 113         else
 114                 res |= S_IFREG;
 115
 116         if (v9fs_extended(v9ses)) {
 117                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
 118                         res |= S_ISUID;
 119
 120                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
 121                         res |= S_ISGID;
 122         }
 123
 124         return res;
 125 }
 126
 127 int v9fs_uflags2omode(int uflags)
 128 {
 129         int ret;
 130
 131         ret = 0;
 132         switch (uflags&3) {
 133         default:
 134         case O_RDONLY:
 135                 ret = P9_OREAD;
 136                 break;
 137
 138         case O_WRONLY:
 139                 ret = P9_OWRITE;
 140                 break;
 141
 142         case O_RDWR:
 143                 ret = P9_ORDWR;
 144                 break;
 145         }
 146
 147         if (uflags & O_EXCL)
 148                 ret |= P9_OEXCL;
 149
 150         if (uflags & O_TRUNC)
 151                 ret |= P9_OTRUNC;
 152
 153         if (uflags & O_APPEND)
 154                 ret |= P9_OAPPEND;
 155
 156         return ret;
 157 }
 158
 159 /**
 160  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 161  * @v9ses: 9P session info (for determining extended mode)
 162  * @wstat: structure to initialize
 163  *
 164  */
 165
 166 static void
 167 v9fs_blank_wstat(struct p9_wstat *wstat)
 168 {
 169         wstat->type = ~0;
 170         wstat->dev = ~0;
 171         wstat->qid.type = ~0;
 172         wstat->qid.version = ~0;
 173         *((long long *)&wstat->qid.path) = ~0;
 174         wstat->mode = ~0;
 175         wstat->atime = ~0;
 176         wstat->mtime = ~0;
 177         wstat->length = ~0;
 178         wstat->name = NULL;
 179         wstat->uid = NULL;
 180         wstat->gid = NULL;
 181         wstat->muid = NULL;
 182         wstat->n_uid = ~0;
 183         wstat->n_gid = ~0;
 184         wstat->n_muid = ~0;
 185         wstat->extension = NULL;
 186 }
 187
 188 /**
 189  * v9fs_get_inode - helper function to setup an inode
 190  * @sb: superblock
 191  * @mode: mode to setup inode with
 192  *
 193  */
 194
 195 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 196 {
 197         struct inode *inode;
 198         struct v9fs_session_info *v9ses = sb->s_fs_info;
 199
 200         P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 201
 202         inode = new_inode(sb);
 203         if (inode) {
 204                 inode->i_mode = mode;
 205                 inode->i_uid = current->fsuid;
 206                 inode->i_gid = current->fsgid;
 207                 inode->i_blocks = 0;
 208                 inode->i_rdev = 0;
 209                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 210                 inode->i_mapping->a_ops = &v9fs_addr_operations;
 211
 212                 switch (mode & S_IFMT) {
 213                 case S_IFIFO:
 214                 case S_IFBLK:
 215                 case S_IFCHR:
 216                 case S_IFSOCK:
 217                         if (!v9fs_extended(v9ses)) {
 218                                 P9_DPRINTK(P9_DEBUG_ERROR,
 219                                       "special files without extended mode\n");
 220                                 return ERR_PTR(-EINVAL);
 221                         }
 222                         init_special_inode(inode, inode->i_mode,
 223                                            inode->i_rdev);
 224                         break;
 225                 case S_IFREG:
 226                         inode->i_op = &v9fs_file_inode_operations;
 227                         inode->i_fop = &v9fs_file_operations;
 228                         break;
 229                 case S_IFLNK:
 230                         if (!v9fs_extended(v9ses)) {
 231                                 P9_DPRINTK(P9_DEBUG_ERROR,
 232                                         "extended modes used w/o 9P2000.u\n");
 233                                 return ERR_PTR(-EINVAL);
 234                         }
 235                         inode->i_op = &v9fs_symlink_inode_operations;
 236                         break;
 237                 case S_IFDIR:
 238                         inc_nlink(inode);
 239                         if (v9fs_extended(v9ses))
 240                                 inode->i_op = &v9fs_dir_inode_operations_ext;
 241                         else
 242                                 inode->i_op = &v9fs_dir_inode_operations;
 243                         inode->i_fop = &v9fs_dir_operations;
 244                         break;
 245                 default:
 246                         P9_DPRINTK(P9_DEBUG_ERROR,
 247                                 "BAD mode 0x%x S_IFMT 0x%x\n",
 248                                 mode, mode & S_IFMT);
 249                         return ERR_PTR(-EINVAL);
 250                 }
 251         } else {
 252                 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
 253                 return ERR_PTR(-ENOMEM);
 254         }
 255         return inode;
 256 }
 257
 258 /*
 259 static struct v9fs_fid*
 260 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 261 {
 262         int err;
 263         int nfid;
 264         struct v9fs_fid *ret;
 265         struct v9fs_fcall *fcall;
 266
 267         nfid = v9fs_get_idpool(&v9ses->fidpool);
 268         if (nfid < 0) {
 269                 eprintk(KERN_WARNING, "no free fids available\n");
 270                 return ERR_PTR(-ENOSPC);
 271         }
 272
 273         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 274                 &fcall);
 275
 276         if (err < 0) {
 277                 if (fcall && fcall->id == RWALK)
 278                         goto clunk_fid;
 279
 280                 PRINT_FCALL_ERROR("walk error", fcall);
 281                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 282                 goto error;
 283         }
 284
 285         kfree(fcall);
 286         fcall = NULL;
 287         ret = v9fs_fid_create(v9ses, nfid);
 288         if (!ret) {
 289                 err = -ENOMEM;
 290                 goto clunk_fid;
 291         }
 292
 293         err = v9fs_fid_insert(ret, dentry);
 294         if (err < 0) {
 295                 v9fs_fid_destroy(ret);
 296                 goto clunk_fid;
 297         }
 298
 299         return ret;
 300
 301 clunk_fid:
 302         v9fs_t_clunk(v9ses, nfid);
 303
 304 error:
 305         kfree(fcall);
 306         return ERR_PTR(err);
 307 }
 308 */
 309
 310 static struct inode *
 311 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 312         struct super_block *sb)
 313 {
 314         int err, umode;
 315         struct inode *ret;
 316         struct p9_stat *st;
 317
 318         ret = NULL;
 319         st = p9_client_stat(fid);
 320         if (IS_ERR(st)) {
 321                 err = PTR_ERR(st);
 322                 st = NULL;
 323                 goto error;
 324         }
 325
 326         umode = p9mode2unixmode(v9ses, st->mode);
 327         ret = v9fs_get_inode(sb, umode);
 328         if (IS_ERR(ret)) {
 329                 err = PTR_ERR(ret);
 330                 ret = NULL;
 331                 goto error;
 332         }
 333
 334         v9fs_stat2inode(st, ret, sb);
 335         ret->i_ino = v9fs_qid2ino(&st->qid);
 336         kfree(st);
 337         return ret;
 338
 339 error:
 340         kfree(st);
 341         if (ret)
 342                 iput(ret);
 343
 344         return ERR_PTR(err);
 345 }
 346
 347 /**
 348  * v9fs_remove - helper function to remove files and directories
 349  * @dir: directory inode that is being deleted
 350  * @file:  dentry that is being deleted
 351  * @rmdir: removing a directory
 352  *
 353  */
 354
 355 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 356 {
 357         struct inode *file_inode;
 358         struct v9fs_session_info *v9ses;
 359         struct p9_fid *v9fid;
 360
 361         P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 362                 rmdir);
 363
 364         file_inode = file->d_inode;
 365         v9ses = v9fs_inode2v9ses(file_inode);
 366         v9fid = v9fs_fid_clone(file);
 367         if (IS_ERR(v9fid))
 368                 return PTR_ERR(v9fid);
 369
 370         return p9_client_remove(v9fid);
 371 }
 372
 373 static int
 374 v9fs_open_created(struct inode *inode, struct file *file)
 375 {
 376         return 0;
 377 }
 378
 379
 380 /**
 381  * v9fs_create - Create a file
 382  * @dentry:  dentry that is being created
 383  * @perm: create permissions
 384  * @mode: open mode
 385  *
 386  */
 387 static struct p9_fid *
 388 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 389                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 390 {
 391         int err;
 392         char *name;
 393         struct p9_fid *dfid, *ofid, *fid;
 394         struct inode *inode;
 395
 396         err = 0;
 397         ofid = NULL;
 398         fid = NULL;
 399         name = (char *) dentry->d_name.name;
 400         dfid = v9fs_fid_clone(dentry->d_parent);
 401         if (IS_ERR(dfid)) {
 402                 err = PTR_ERR(dfid);
 403                 dfid = NULL;
 404                 goto error;
 405         }
 406
 407         /* clone a fid to use for creation */
 408         ofid = p9_client_walk(dfid, 0, NULL, 1);
 409         if (IS_ERR(ofid)) {
 410                 err = PTR_ERR(ofid);
 411                 ofid = NULL;
 412                 goto error;
 413         }
 414
 415         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 416         if (err < 0)
 417                 goto error;
 418
 419         /* now walk from the parent so we can get unopened fid */
 420         fid = p9_client_walk(dfid, 1, &name, 0);
 421         if (IS_ERR(fid)) {
 422                 err = PTR_ERR(fid);
 423                 fid = NULL;
 424                 goto error;
 425         } else
 426                 dfid = NULL;
 427
 428         /* instantiate inode and assign the unopened fid to the dentry */
 429         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 430         if (IS_ERR(inode)) {
 431                 err = PTR_ERR(inode);
 432                 goto error;
 433         }
 434
 435         if (v9ses->cache)
 436                 dentry->d_op = &v9fs_cached_dentry_operations;
 437         else
 438                 dentry->d_op = &v9fs_dentry_operations;
 439
 440         d_instantiate(dentry, inode);
 441         v9fs_fid_add(dentry, fid);
 442         return ofid;
 443
 444 error:
 445         if (dfid)
 446                 p9_client_clunk(dfid);
 447
 448         if (ofid)
 449                 p9_client_clunk(ofid);
 450
 451         if (fid)
 452                 p9_client_clunk(fid);
 453
 454         return ERR_PTR(err);
 455 }
 456
 457 /**
 458  * v9fs_vfs_create - VFS hook to create files
 459  * @inode: directory inode that is being created
 460  * @dentry:  dentry that is being deleted
 461  * @mode: create permissions
 462  * @nd: path information
 463  *
 464  */
 465
 466 static int
 467 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 468                 struct nameidata *nd)
 469 {
 470         int err;
 471         u32 perm;
 472         int flags;
 473         struct v9fs_session_info *v9ses;
 474         struct p9_fid *fid;
 475         struct file *filp;
 476
 477         err = 0;
 478         fid = NULL;
 479         v9ses = v9fs_inode2v9ses(dir);
 480         perm = unixmode2p9mode(v9ses, mode);
 481         if (nd && nd->flags & LOOKUP_OPEN)
 482                 flags = nd->intent.open.flags - 1;
 483         else
 484                 flags = O_RDWR;
 485
 486         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 487                                                 v9fs_uflags2omode(flags));
 488         if (IS_ERR(fid)) {
 489                 err = PTR_ERR(fid);
 490                 fid = NULL;
 491                 goto error;
 492         }
 493
 494         /* if we are opening a file, assign the open fid to the file */
 495         if (nd && nd->flags & LOOKUP_OPEN) {
 496                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 497                 if (IS_ERR(filp)) {
 498                         err = PTR_ERR(filp);
 499                         goto error;
 500                 }
 501
 502                 filp->private_data = fid;
 503         } else
 504                 p9_client_clunk(fid);
 505
 506         return 0;
 507
 508 error:
 509         if (fid)
 510                 p9_client_clunk(fid);
 511
 512         return err;
 513 }
 514
 515 /**
 516  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 517  * @inode:  inode that is being unlinked
 518  * @dentry: dentry that is being unlinked
 519  * @mode: mode for new directory
 520  *
 521  */
 522
 523 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 524 {
 525         int err;
 526         u32 perm;
 527         struct v9fs_session_info *v9ses;
 528         struct p9_fid *fid;
 529
 530         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 531         err = 0;
 532         v9ses = v9fs_inode2v9ses(dir);
 533         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 534         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 535         if (IS_ERR(fid)) {
 536                 err = PTR_ERR(fid);
 537                 fid = NULL;
 538         }
 539
 540         if (fid)
 541                 p9_client_clunk(fid);
 542
 543         return err;
 544 }
 545
 546 /**
 547  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 548  * @dir:  inode that is being walked from
 549  * @dentry: dentry that is being walked to?
 550  * @nameidata: path data
 551  *
 552  */
 553
 554 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 555                                       struct nameidata *nameidata)
 556 {
 557         struct super_block *sb;
 558         struct v9fs_session_info *v9ses;
 559         struct p9_fid *dfid, *fid;
 560         struct inode *inode;
 561         char *name;
 562         int result = 0;
 563
 564         P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 565                 dir, dentry->d_name.name, dentry, nameidata);
 566
 567         sb = dir->i_sb;
 568         v9ses = v9fs_inode2v9ses(dir);
 569         dfid = v9fs_fid_lookup(dentry->d_parent);
 570         if (IS_ERR(dfid))
 571                 return ERR_PTR(PTR_ERR(dfid));
 572
 573         name = (char *) dentry->d_name.name;
 574         fid = p9_client_walk(dfid, 1, &name, 1);
 575         if (IS_ERR(fid)) {
 576                 result = PTR_ERR(fid);
 577                 if (result == -ENOENT) {
 578                         d_add(dentry, NULL);
 579                         return NULL;
 580                 }
 581
 582                 return ERR_PTR(result);
 583         }
 584
 585         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 586         if (IS_ERR(inode)) {
 587                 result = PTR_ERR(inode);
 588                 inode = NULL;
 589                 goto error;
 590         }
 591
 592         result = v9fs_fid_add(dentry, fid);
 593         if (result < 0)
 594                 goto error;
 595
 596         if ((fid->qid.version) && (v9ses->cache))
 597                 dentry->d_op = &v9fs_cached_dentry_operations;
 598         else
 599                 dentry->d_op = &v9fs_dentry_operations;
 600
 601         d_add(dentry, inode);
 602         return NULL;
 603
 604 error:
 605         if (fid)
 606                 p9_client_clunk(fid);
 607
 608         return ERR_PTR(result);
 609 }
 610
 611 /**
 612  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 613  * @i:  inode that is being unlinked
 614  * @d: dentry that is being unlinked
 615  *
 616  */
 617
 618 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 619 {
 620         return v9fs_remove(i, d, 0);
 621 }
 622
 623 /**
 624  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 625  * @i:  inode that is being unlinked
 626  * @d: dentry that is being unlinked
 627  *
 628  */
 629
 630 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 631 {
 632         return v9fs_remove(i, d, 1);
 633 }
 634
 635 /**
 636  * v9fs_vfs_rename - VFS hook to rename an inode
 637  * @old_dir:  old dir inode
 638  * @old_dentry: old dentry
 639  * @new_dir: new dir inode
 640  * @new_dentry: new dentry
 641  *
 642  */
 643
 644 static int
 645 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 646                 struct inode *new_dir, struct dentry *new_dentry)
 647 {
 648         struct inode *old_inode;
 649         struct v9fs_session_info *v9ses;
 650         struct p9_fid *oldfid;
 651         struct p9_fid *olddirfid;
 652         struct p9_fid *newdirfid;
 653         struct p9_wstat wstat;
 654         int retval;
 655
 656         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 657         retval = 0;
 658         old_inode = old_dentry->d_inode;
 659         v9ses = v9fs_inode2v9ses(old_inode);
 660         oldfid = v9fs_fid_lookup(old_dentry);
 661         if (IS_ERR(oldfid))
 662                 return PTR_ERR(oldfid);
 663
 664         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 665         if (IS_ERR(olddirfid)) {
 666                 retval = PTR_ERR(olddirfid);
 667                 goto done;
 668         }
 669
 670         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 671         if (IS_ERR(newdirfid)) {
 672                 retval = PTR_ERR(newdirfid);
 673                 goto clunk_olddir;
 674         }
 675
 676         /* 9P can only handle file rename in the same directory */
 677         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 678                 P9_DPRINTK(P9_DEBUG_ERROR,
 679                                 "old dir and new dir are different\n");
 680                 retval = -EXDEV;
 681                 goto clunk_newdir;
 682         }
 683
 684         v9fs_blank_wstat(&wstat);
 685         wstat.muid = v9ses->uname;
 686         wstat.name = (char *) new_dentry->d_name.name;
 687         retval = p9_client_wstat(oldfid, &wstat);
 688
 689 clunk_newdir:
 690         p9_client_clunk(newdirfid);
 691
 692 clunk_olddir:
 693         p9_client_clunk(olddirfid);
 694
 695 done:
 696         return retval;
 697 }
 698
 699 /**
 700  * v9fs_vfs_getattr - retrieve file metadata
 701  * @mnt - mount information
 702  * @dentry - file to get attributes on
 703  * @stat - metadata structure to populate
 704  *
 705  */
 706
 707 static int
 708 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 709                  struct kstat *stat)
 710 {
 711         int err;
 712         struct v9fs_session_info *v9ses;
 713         struct p9_fid *fid;
 714         struct p9_stat *st;
 715
 716         P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 717         err = -EPERM;
 718         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 719         if (v9ses->cache == CACHE_LOOSE)
 720                 return simple_getattr(mnt, dentry, stat);
 721
 722         fid = v9fs_fid_lookup(dentry);
 723         if (IS_ERR(fid))
 724                 return PTR_ERR(fid);
 725
 726         st = p9_client_stat(fid);
 727         if (IS_ERR(st))
 728                 return PTR_ERR(st);
 729
 730         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
 731                 generic_fillattr(dentry->d_inode, stat);
 732
 733         kfree(st);
 734         return 0;
 735 }
 736
 737 /**
 738  * v9fs_vfs_setattr - set file metadata
 739  * @dentry: file whose metadata to set
 740  * @iattr: metadata assignment structure
 741  *
 742  */
 743
 744 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 745 {
 746         int retval;
 747         struct v9fs_session_info *v9ses;
 748         struct p9_fid *fid;
 749         struct p9_wstat wstat;
 750
 751         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 752         retval = -EPERM;
 753         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 754         fid = v9fs_fid_lookup(dentry);
 755         if(IS_ERR(fid))
 756                 return PTR_ERR(fid);
 757
 758         v9fs_blank_wstat(&wstat);
 759         if (iattr->ia_valid & ATTR_MODE)
 760                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 761
 762         if (iattr->ia_valid & ATTR_MTIME)
 763                 wstat.mtime = iattr->ia_mtime.tv_sec;
 764
 765         if (iattr->ia_valid & ATTR_ATIME)
 766                 wstat.atime = iattr->ia_atime.tv_sec;
 767
 768         if (iattr->ia_valid & ATTR_SIZE)
 769                 wstat.length = iattr->ia_size;
 770
 771         if (v9fs_extended(v9ses)) {
 772                 if (iattr->ia_valid & ATTR_UID)
 773                         wstat.n_uid = iattr->ia_uid;
 774
 775                 if (iattr->ia_valid & ATTR_GID)
 776                         wstat.n_gid = iattr->ia_gid;
 777         }
 778
 779         retval = p9_client_wstat(fid, &wstat);
 780         if (retval >= 0)
 781                 retval = inode_setattr(dentry->d_inode, iattr);
 782
 783         return retval;
 784 }
 785
 786 /**
 787  * v9fs_stat2inode - populate an inode structure with mistat info
 788  * @stat: Plan 9 metadata (mistat) structure
 789  * @inode: inode to populate
 790  * @sb: superblock of filesystem
 791  *
 792  */
 793
 794 void
 795 v9fs_stat2inode(struct p9_stat *stat, struct inode *inode,
 796         struct super_block *sb)
 797 {
 798         int n;
 799         char ext[32];
 800         struct v9fs_session_info *v9ses = sb->s_fs_info;
 801
 802         inode->i_nlink = 1;
 803
 804         inode->i_atime.tv_sec = stat->atime;
 805         inode->i_mtime.tv_sec = stat->mtime;
 806         inode->i_ctime.tv_sec = stat->mtime;
 807
 808         inode->i_uid = v9ses->dfltuid;
 809         inode->i_gid = v9ses->dfltgid;
 810
 811         if (v9fs_extended(v9ses)) {
 812                 inode->i_uid = stat->n_uid;
 813                 inode->i_gid = stat->n_gid;
 814         }
 815
 816         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 817         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 818                 char type = 0;
 819                 int major = -1;
 820                 int minor = -1;
 821
 822                 n = stat->extension.len;
 823                 if (n > sizeof(ext)-1)
 824                         n = sizeof(ext)-1;
 825                 memmove(ext, stat->extension.str, n);
 826                 ext[n] = 0;
 827                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 828                 switch (type) {
 829                 case 'c':
 830                         inode->i_mode &= ~S_IFBLK;
 831                         inode->i_mode |= S_IFCHR;
 832                         break;
 833                 case 'b':
 834                         break;
 835                 default:
 836                         P9_DPRINTK(P9_DEBUG_ERROR,
 837                                 "Unknown special type %c (%.*s)\n", type,
 838                                 stat->extension.len, stat->extension.str);
 839                 };
 840                 inode->i_rdev = MKDEV(major, minor);
 841         } else
 842                 inode->i_rdev = 0;
 843
 844         inode->i_size = stat->length;
 845
 846         /* not real number of blocks, but 512 byte ones ... */
 847         inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
 848 }
 849
 850 /**
 851  * v9fs_qid2ino - convert qid into inode number
 852  * @qid: qid to hash
 853  *
 854  * BUG: potential for inode number collisions?
 855  */
 856
 857 ino_t v9fs_qid2ino(struct p9_qid *qid)
 858 {
 859         u64 path = qid->path + 2;
 860         ino_t i = 0;
 861
 862         if (sizeof(ino_t) == sizeof(path))
 863                 memcpy(&i, &path, sizeof(ino_t));
 864         else
 865                 i = (ino_t) (path ^ (path >> 32));
 866
 867         return i;
 868 }
 869
 870 /**
 871  * v9fs_readlink - read a symlink's location (internal version)
 872  * @dentry: dentry for symlink
 873  * @buffer: buffer to load symlink location into
 874  * @buflen: length of buffer
 875  *
 876  */
 877
 878 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 879 {
 880         int retval;
 881
 882         struct v9fs_session_info *v9ses;
 883         struct p9_fid *fid;
 884         struct p9_stat *st;
 885
 886         P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
 887         retval = -EPERM;
 888         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 889         fid = v9fs_fid_lookup(dentry);
 890         if (IS_ERR(fid))
 891                 return PTR_ERR(fid);
 892
 893         if (!v9fs_extended(v9ses))
 894                 return -EBADF;
 895
 896         st = p9_client_stat(fid);
 897         if (IS_ERR(st))
 898                 return PTR_ERR(st);
 899
 900         if (!(st->mode & P9_DMSYMLINK)) {
 901                 retval = -EINVAL;
 902                 goto done;
 903         }
 904
 905         /* copy extension buffer into buffer */
 906         if (st->extension.len < buflen)
 907                 buflen = st->extension.len + 1;
 908
 909         memmove(buffer, st->extension.str, buflen - 1);
 910         buffer[buflen-1] = 0;
 911
 912         P9_DPRINTK(P9_DEBUG_VFS,
 913                 "%s -> %.*s (%s)\n", dentry->d_name.name, st->extension.len,
 914                 st->extension.str, buffer);
 915
 916         retval = buflen;
 917
 918 done:
 919         kfree(st);
 920         return retval;
 921 }
 922
 923 /**
 924  * v9fs_vfs_readlink - read a symlink's location
 925  * @dentry: dentry for symlink
 926  * @buf: buffer to load symlink location into
 927  * @buflen: length of buffer
 928  *
 929  */
 930
 931 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
 932                              int buflen)
 933 {
 934         int retval;
 935         int ret;
 936         char *link = __getname();
 937
 938         if (unlikely(!link))
 939                 return -ENOMEM;
 940
 941         if (buflen > PATH_MAX)
 942                 buflen = PATH_MAX;
 943
 944         P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
 945
 946         retval = v9fs_readlink(dentry, link, buflen);
 947
 948         if (retval > 0) {
 949                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
 950                         P9_DPRINTK(P9_DEBUG_ERROR,
 951                                         "problem copying to user: %d\n", ret);
 952                         retval = ret;
 953                 }
 954         }
 955
 956         __putname(link);
 957         return retval;
 958 }
 959
 960 /**
 961  * v9fs_vfs_follow_link - follow a symlink path
 962  * @dentry: dentry for symlink
 963  * @nd: nameidata
 964  *
 965  */
 966
 967 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 968 {
 969         int len = 0;
 970         char *link = __getname();
 971
 972         P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
 973
 974         if (!link)
 975                 link = ERR_PTR(-ENOMEM);
 976         else {
 977                 len = v9fs_readlink(dentry, link, PATH_MAX);
 978
 979                 if (len < 0) {
 980                         __putname(link);
 981                         link = ERR_PTR(len);
 982                 } else
 983                         link[len] = 0;
 984         }
 985         nd_set_link(nd, link);
 986
 987         return NULL;
 988 }
 989
 990 /**
 991  * v9fs_vfs_put_link - release a symlink path
 992  * @dentry: dentry for symlink
 993  * @nd: nameidata
 994  *
 995  */
 996
 997 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
 998 {
 999         char *s = nd_get_link(nd);
1000
1001         P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1002         if (!IS_ERR(s))
1003                 __putname(s);
1004 }
1005
1006 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1007         int mode, const char *extension)
1008 {
1009         u32 perm;
1010         struct v9fs_session_info *v9ses;
1011         struct p9_fid *fid;
1012
1013         v9ses = v9fs_inode2v9ses(dir);
1014         if (!v9fs_extended(v9ses)) {
1015                 P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1016                 return -EPERM;
1017         }
1018
1019         perm = unixmode2p9mode(v9ses, mode);
1020         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1021                                                                 P9_OREAD);
1022         if (IS_ERR(fid))
1023                 return PTR_ERR(fid);
1024
1025         p9_client_clunk(fid);
1026         return 0;
1027 }
1028
1029 /**
1030  * v9fs_vfs_symlink - helper function to create symlinks
1031  * @dir: directory inode containing symlink
1032  * @dentry: dentry for symlink
1033  * @symname: symlink data
1034  *
1035  * See 9P2000.u RFC for more information
1036  *
1037  */
1038
1039 static int
1040 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1041 {
1042         P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1043                                         dentry->d_name.name, symname);
1044
1045         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1046 }
1047
1048 /**
1049  * v9fs_vfs_link - create a hardlink
1050  * @old_dentry: dentry for file to link to
1051  * @dir: inode destination for new link
1052  * @dentry: dentry for link
1053  *
1054  */
1055
1056 /* XXX - lots of code dup'd from symlink and creates,
1057  * figure out a better reuse strategy
1058  */
1059
1060 static int
1061 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1062               struct dentry *dentry)
1063 {
1064         int retval;
1065         struct p9_fid *oldfid;
1066         char *name;
1067
1068         P9_DPRINTK(P9_DEBUG_VFS,
1069                 " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1070                 old_dentry->d_name.name);
1071
1072         oldfid = v9fs_fid_clone(old_dentry);
1073         if (IS_ERR(oldfid))
1074                 return PTR_ERR(oldfid);
1075
1076         name = __getname();
1077         if (unlikely(!name)) {
1078                 retval = -ENOMEM;
1079                 goto clunk_fid;
1080         }
1081
1082         sprintf(name, "%d\n", oldfid->fid);
1083         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1084         __putname(name);
1085
1086 clunk_fid:
1087         p9_client_clunk(oldfid);
1088         return retval;
1089 }
1090
1091 /**
1092  * v9fs_vfs_mknod - create a special file
1093  * @dir: inode destination for new link
1094  * @dentry: dentry for file
1095  * @mode: mode for creation
1096  * @dev_t: device associated with special file
1097  *
1098  */
1099
1100 static int
1101 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1102 {
1103         int retval;
1104         char *name;
1105
1106         P9_DPRINTK(P9_DEBUG_VFS,
1107                 " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1108                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1109
1110         if (!new_valid_dev(rdev))
1111                 return -EINVAL;
1112
1113         name = __getname();
1114         if (!name)
1115                 return -ENOMEM;
1116         /* build extension */
1117         if (S_ISBLK(mode))
1118                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1119         else if (S_ISCHR(mode))
1120                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1121         else if (S_ISFIFO(mode))
1122                 *name = 0;
1123         else {
1124                 __putname(name);
1125                 return -EINVAL;
1126         }
1127
1128         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1129         __putname(name);
1130
1131         return retval;
1132 }
1133
1134 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1135         .create = v9fs_vfs_create,
1136         .lookup = v9fs_vfs_lookup,
1137         .symlink = v9fs_vfs_symlink,
1138         .link = v9fs_vfs_link,
1139         .unlink = v9fs_vfs_unlink,
1140         .mkdir = v9fs_vfs_mkdir,
1141         .rmdir = v9fs_vfs_rmdir,
1142         .mknod = v9fs_vfs_mknod,
1143         .rename = v9fs_vfs_rename,
1144         .readlink = v9fs_vfs_readlink,
1145         .getattr = v9fs_vfs_getattr,
1146         .setattr = v9fs_vfs_setattr,
1147 };
1148
1149 static const struct inode_operations v9fs_dir_inode_operations = {
1150         .create = v9fs_vfs_create,
1151         .lookup = v9fs_vfs_lookup,
1152         .unlink = v9fs_vfs_unlink,
1153         .mkdir = v9fs_vfs_mkdir,
1154         .rmdir = v9fs_vfs_rmdir,
1155         .mknod = v9fs_vfs_mknod,
1156         .rename = v9fs_vfs_rename,
1157         .getattr = v9fs_vfs_getattr,
1158         .setattr = v9fs_vfs_setattr,
1159 };
1160
1161 static const struct inode_operations v9fs_file_inode_operations = {
1162         .getattr = v9fs_vfs_getattr,
1163         .setattr = v9fs_vfs_setattr,
1164 };
1165
1166 static const struct inode_operations v9fs_symlink_inode_operations = {
1167         .readlink = v9fs_vfs_readlink,
1168         .follow_link = v9fs_vfs_follow_link,
1169         .put_link = v9fs_vfs_put_link,
1170         .getattr = v9fs_vfs_getattr,
1171         .setattr = v9fs_vfs_setattr,
1172 };