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  *
 136  */
 137
 138 int v9fs_uflags2omode(int uflags)
 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_EXCL)
 159                 ret |= P9_OEXCL;
 160
 161         if (uflags & O_TRUNC)
 162                 ret |= P9_OTRUNC;
 163
 164         if (uflags & O_APPEND)
 165                 ret |= P9_OAPPEND;
 166
 167         return ret;
 168 }
 169
 170 /**
 171  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 172  * @v9ses: 9P session info (for determining extended mode)
 173  * @wstat: structure to initialize
 174  *
 175  */
 176
 177 static void
 178 v9fs_blank_wstat(struct p9_wstat *wstat)
 179 {
 180         wstat->type = ~0;
 181         wstat->dev = ~0;
 182         wstat->qid.type = ~0;
 183         wstat->qid.version = ~0;
 184         *((long long *)&wstat->qid.path) = ~0;
 185         wstat->mode = ~0;
 186         wstat->atime = ~0;
 187         wstat->mtime = ~0;
 188         wstat->length = ~0;
 189         wstat->name = NULL;
 190         wstat->uid = NULL;
 191         wstat->gid = NULL;
 192         wstat->muid = NULL;
 193         wstat->n_uid = ~0;
 194         wstat->n_gid = ~0;
 195         wstat->n_muid = ~0;
 196         wstat->extension = NULL;
 197 }
 198
 199 /**
 200  * v9fs_get_inode - helper function to setup an inode
 201  * @sb: superblock
 202  * @mode: mode to setup inode with
 203  *
 204  */
 205
 206 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 207 {
 208         struct inode *inode;
 209         struct v9fs_session_info *v9ses = sb->s_fs_info;
 210
 211         P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 212
 213         inode = new_inode(sb);
 214         if (inode) {
 215                 inode->i_mode = mode;
 216                 inode->i_uid = current->fsuid;
 217                 inode->i_gid = current->fsgid;
 218                 inode->i_blocks = 0;
 219                 inode->i_rdev = 0;
 220                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 221                 inode->i_mapping->a_ops = &v9fs_addr_operations;
 222
 223                 switch (mode & S_IFMT) {
 224                 case S_IFIFO:
 225                 case S_IFBLK:
 226                 case S_IFCHR:
 227                 case S_IFSOCK:
 228                         if (!v9fs_extended(v9ses)) {
 229                                 P9_DPRINTK(P9_DEBUG_ERROR,
 230                                       "special files without extended mode\n");
 231                                 return ERR_PTR(-EINVAL);
 232                         }
 233                         init_special_inode(inode, inode->i_mode,
 234                                            inode->i_rdev);
 235                         break;
 236                 case S_IFREG:
 237                         inode->i_op = &v9fs_file_inode_operations;
 238                         inode->i_fop = &v9fs_file_operations;
 239                         break;
 240                 case S_IFLNK:
 241                         if (!v9fs_extended(v9ses)) {
 242                                 P9_DPRINTK(P9_DEBUG_ERROR,
 243                                         "extended modes used w/o 9P2000.u\n");
 244                                 return ERR_PTR(-EINVAL);
 245                         }
 246                         inode->i_op = &v9fs_symlink_inode_operations;
 247                         break;
 248                 case S_IFDIR:
 249                         inc_nlink(inode);
 250                         if (v9fs_extended(v9ses))
 251                                 inode->i_op = &v9fs_dir_inode_operations_ext;
 252                         else
 253                                 inode->i_op = &v9fs_dir_inode_operations;
 254                         inode->i_fop = &v9fs_dir_operations;
 255                         break;
 256                 default:
 257                         P9_DPRINTK(P9_DEBUG_ERROR,
 258                                 "BAD mode 0x%x S_IFMT 0x%x\n",
 259                                 mode, mode & S_IFMT);
 260                         return ERR_PTR(-EINVAL);
 261                 }
 262         } else {
 263                 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
 264                 return ERR_PTR(-ENOMEM);
 265         }
 266         return inode;
 267 }
 268
 269 /*
 270 static struct v9fs_fid*
 271 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 272 {
 273         int err;
 274         int nfid;
 275         struct v9fs_fid *ret;
 276         struct v9fs_fcall *fcall;
 277
 278         nfid = v9fs_get_idpool(&v9ses->fidpool);
 279         if (nfid < 0) {
 280                 eprintk(KERN_WARNING, "no free fids available\n");
 281                 return ERR_PTR(-ENOSPC);
 282         }
 283
 284         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 285                 &fcall);
 286
 287         if (err < 0) {
 288                 if (fcall && fcall->id == RWALK)
 289                         goto clunk_fid;
 290
 291                 PRINT_FCALL_ERROR("walk error", fcall);
 292                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 293                 goto error;
 294         }
 295
 296         kfree(fcall);
 297         fcall = NULL;
 298         ret = v9fs_fid_create(v9ses, nfid);
 299         if (!ret) {
 300                 err = -ENOMEM;
 301                 goto clunk_fid;
 302         }
 303
 304         err = v9fs_fid_insert(ret, dentry);
 305         if (err < 0) {
 306                 v9fs_fid_destroy(ret);
 307                 goto clunk_fid;
 308         }
 309
 310         return ret;
 311
 312 clunk_fid:
 313         v9fs_t_clunk(v9ses, nfid);
 314
 315 error:
 316         kfree(fcall);
 317         return ERR_PTR(err);
 318 }
 319 */
 320
 321 /**
 322  * v9fs_inode_from_fid - populate an inode by issuing a attribute request
 323  * @v9ses: session information
 324  * @fid: fid to issue attribute request for
 325  * @sb: superblock on which to create inode
 326  *
 327  */
 328
 329 static struct inode *
 330 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 331         struct super_block *sb)
 332 {
 333         int err, umode;
 334         struct inode *ret;
 335         struct p9_stat *st;
 336
 337         ret = NULL;
 338         st = p9_client_stat(fid);
 339         if (IS_ERR(st)) {
 340                 err = PTR_ERR(st);
 341                 st = NULL;
 342                 goto error;
 343         }
 344
 345         umode = p9mode2unixmode(v9ses, st->mode);
 346         ret = v9fs_get_inode(sb, umode);
 347         if (IS_ERR(ret)) {
 348                 err = PTR_ERR(ret);
 349                 ret = NULL;
 350                 goto error;
 351         }
 352
 353         v9fs_stat2inode(st, ret, sb);
 354         ret->i_ino = v9fs_qid2ino(&st->qid);
 355         kfree(st);
 356         return ret;
 357
 358 error:
 359         kfree(st);
 360         if (ret)
 361                 iput(ret);
 362
 363         return ERR_PTR(err);
 364 }
 365
 366 /**
 367  * v9fs_remove - helper function to remove files and directories
 368  * @dir: directory inode that is being deleted
 369  * @file:  dentry that is being deleted
 370  * @rmdir: removing a directory
 371  *
 372  */
 373
 374 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 375 {
 376         struct inode *file_inode;
 377         struct v9fs_session_info *v9ses;
 378         struct p9_fid *v9fid;
 379
 380         P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 381                 rmdir);
 382
 383         file_inode = file->d_inode;
 384         v9ses = v9fs_inode2v9ses(file_inode);
 385         v9fid = v9fs_fid_clone(file);
 386         if (IS_ERR(v9fid))
 387                 return PTR_ERR(v9fid);
 388
 389         return p9_client_remove(v9fid);
 390 }
 391
 392 static int
 393 v9fs_open_created(struct inode *inode, struct file *file)
 394 {
 395         return 0;
 396 }
 397
 398
 399 /**
 400  * v9fs_create - Create a file
 401  * @v9ses: session information
 402  * @dir: directory that dentry is being created in
 403  * @dentry:  dentry that is being created
 404  * @perm: create permissions
 405  * @mode: open mode
 406  * @extension: 9p2000.u extension string to support devices, etc.
 407  *
 408  */
 409 static struct p9_fid *
 410 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 411                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 412 {
 413         int err;
 414         char *name;
 415         struct p9_fid *dfid, *ofid, *fid;
 416         struct inode *inode;
 417
 418         err = 0;
 419         ofid = NULL;
 420         fid = NULL;
 421         name = (char *) dentry->d_name.name;
 422         dfid = v9fs_fid_clone(dentry->d_parent);
 423         if (IS_ERR(dfid)) {
 424                 err = PTR_ERR(dfid);
 425                 dfid = NULL;
 426                 goto error;
 427         }
 428
 429         /* clone a fid to use for creation */
 430         ofid = p9_client_walk(dfid, 0, NULL, 1);
 431         if (IS_ERR(ofid)) {
 432                 err = PTR_ERR(ofid);
 433                 ofid = NULL;
 434                 goto error;
 435         }
 436
 437         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 438         if (err < 0)
 439                 goto error;
 440
 441         /* now walk from the parent so we can get unopened fid */
 442         fid = p9_client_walk(dfid, 1, &name, 0);
 443         if (IS_ERR(fid)) {
 444                 err = PTR_ERR(fid);
 445                 fid = NULL;
 446                 goto error;
 447         } else
 448                 dfid = NULL;
 449
 450         /* instantiate inode and assign the unopened fid to the dentry */
 451         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 452         if (IS_ERR(inode)) {
 453                 err = PTR_ERR(inode);
 454                 goto error;
 455         }
 456
 457         if (v9ses->cache)
 458                 dentry->d_op = &v9fs_cached_dentry_operations;
 459         else
 460                 dentry->d_op = &v9fs_dentry_operations;
 461
 462         d_instantiate(dentry, inode);
 463         v9fs_fid_add(dentry, fid);
 464         return ofid;
 465
 466 error:
 467         if (dfid)
 468                 p9_client_clunk(dfid);
 469
 470         if (ofid)
 471                 p9_client_clunk(ofid);
 472
 473         if (fid)
 474                 p9_client_clunk(fid);
 475
 476         return ERR_PTR(err);
 477 }
 478
 479 /**
 480  * v9fs_vfs_create - VFS hook to create files
 481  * @dir: directory inode that is being created
 482  * @dentry:  dentry that is being deleted
 483  * @mode: create permissions
 484  * @nd: path information
 485  *
 486  */
 487
 488 static int
 489 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 490                 struct nameidata *nd)
 491 {
 492         int err;
 493         u32 perm;
 494         int flags;
 495         struct v9fs_session_info *v9ses;
 496         struct p9_fid *fid;
 497         struct file *filp;
 498
 499         err = 0;
 500         fid = NULL;
 501         v9ses = v9fs_inode2v9ses(dir);
 502         perm = unixmode2p9mode(v9ses, mode);
 503         if (nd && nd->flags & LOOKUP_OPEN)
 504                 flags = nd->intent.open.flags - 1;
 505         else
 506                 flags = O_RDWR;
 507
 508         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 509                                                 v9fs_uflags2omode(flags));
 510         if (IS_ERR(fid)) {
 511                 err = PTR_ERR(fid);
 512                 fid = NULL;
 513                 goto error;
 514         }
 515
 516         /* if we are opening a file, assign the open fid to the file */
 517         if (nd && nd->flags & LOOKUP_OPEN) {
 518                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 519                 if (IS_ERR(filp)) {
 520                         err = PTR_ERR(filp);
 521                         goto error;
 522                 }
 523
 524                 filp->private_data = fid;
 525         } else
 526                 p9_client_clunk(fid);
 527
 528         return 0;
 529
 530 error:
 531         if (fid)
 532                 p9_client_clunk(fid);
 533
 534         return err;
 535 }
 536
 537 /**
 538  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 539  * @dir:  inode that is being unlinked
 540  * @dentry: dentry that is being unlinked
 541  * @mode: mode for new directory
 542  *
 543  */
 544
 545 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 546 {
 547         int err;
 548         u32 perm;
 549         struct v9fs_session_info *v9ses;
 550         struct p9_fid *fid;
 551
 552         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 553         err = 0;
 554         v9ses = v9fs_inode2v9ses(dir);
 555         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 556         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 557         if (IS_ERR(fid)) {
 558                 err = PTR_ERR(fid);
 559                 fid = NULL;
 560         }
 561
 562         if (fid)
 563                 p9_client_clunk(fid);
 564
 565         return err;
 566 }
 567
 568 /**
 569  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 570  * @dir:  inode that is being walked from
 571  * @dentry: dentry that is being walked to?
 572  * @nameidata: path data
 573  *
 574  */
 575
 576 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 577                                       struct nameidata *nameidata)
 578 {
 579         struct super_block *sb;
 580         struct v9fs_session_info *v9ses;
 581         struct p9_fid *dfid, *fid;
 582         struct inode *inode;
 583         char *name;
 584         int result = 0;
 585
 586         P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 587                 dir, dentry->d_name.name, dentry, nameidata);
 588
 589         sb = dir->i_sb;
 590         v9ses = v9fs_inode2v9ses(dir);
 591         dfid = v9fs_fid_lookup(dentry->d_parent);
 592         if (IS_ERR(dfid))
 593                 return ERR_CAST(dfid);
 594
 595         name = (char *) dentry->d_name.name;
 596         fid = p9_client_walk(dfid, 1, &name, 1);
 597         if (IS_ERR(fid)) {
 598                 result = PTR_ERR(fid);
 599                 if (result == -ENOENT) {
 600                         d_add(dentry, NULL);
 601                         return NULL;
 602                 }
 603
 604                 return ERR_PTR(result);
 605         }
 606
 607         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 608         if (IS_ERR(inode)) {
 609                 result = PTR_ERR(inode);
 610                 inode = NULL;
 611                 goto error;
 612         }
 613
 614         result = v9fs_fid_add(dentry, fid);
 615         if (result < 0)
 616                 goto error;
 617
 618         if ((fid->qid.version) && (v9ses->cache))
 619                 dentry->d_op = &v9fs_cached_dentry_operations;
 620         else
 621                 dentry->d_op = &v9fs_dentry_operations;
 622
 623         d_add(dentry, inode);
 624         return NULL;
 625
 626 error:
 627         if (fid)
 628                 p9_client_clunk(fid);
 629
 630         return ERR_PTR(result);
 631 }
 632
 633 /**
 634  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 635  * @i:  inode that is being unlinked
 636  * @d: dentry that is being unlinked
 637  *
 638  */
 639
 640 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 641 {
 642         return v9fs_remove(i, d, 0);
 643 }
 644
 645 /**
 646  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 647  * @i:  inode that is being unlinked
 648  * @d: dentry that is being unlinked
 649  *
 650  */
 651
 652 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 653 {
 654         return v9fs_remove(i, d, 1);
 655 }
 656
 657 /**
 658  * v9fs_vfs_rename - VFS hook to rename an inode
 659  * @old_dir:  old dir inode
 660  * @old_dentry: old dentry
 661  * @new_dir: new dir inode
 662  * @new_dentry: new dentry
 663  *
 664  */
 665
 666 static int
 667 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 668                 struct inode *new_dir, struct dentry *new_dentry)
 669 {
 670         struct inode *old_inode;
 671         struct v9fs_session_info *v9ses;
 672         struct p9_fid *oldfid;
 673         struct p9_fid *olddirfid;
 674         struct p9_fid *newdirfid;
 675         struct p9_wstat wstat;
 676         int retval;
 677
 678         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 679         retval = 0;
 680         old_inode = old_dentry->d_inode;
 681         v9ses = v9fs_inode2v9ses(old_inode);
 682         oldfid = v9fs_fid_lookup(old_dentry);
 683         if (IS_ERR(oldfid))
 684                 return PTR_ERR(oldfid);
 685
 686         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 687         if (IS_ERR(olddirfid)) {
 688                 retval = PTR_ERR(olddirfid);
 689                 goto done;
 690         }
 691
 692         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 693         if (IS_ERR(newdirfid)) {
 694                 retval = PTR_ERR(newdirfid);
 695                 goto clunk_olddir;
 696         }
 697
 698         /* 9P can only handle file rename in the same directory */
 699         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 700                 P9_DPRINTK(P9_DEBUG_ERROR,
 701                                 "old dir and new dir are different\n");
 702                 retval = -EXDEV;
 703                 goto clunk_newdir;
 704         }
 705
 706         v9fs_blank_wstat(&wstat);
 707         wstat.muid = v9ses->uname;
 708         wstat.name = (char *) new_dentry->d_name.name;
 709         retval = p9_client_wstat(oldfid, &wstat);
 710
 711 clunk_newdir:
 712         p9_client_clunk(newdirfid);
 713
 714 clunk_olddir:
 715         p9_client_clunk(olddirfid);
 716
 717 done:
 718         return retval;
 719 }
 720
 721 /**
 722  * v9fs_vfs_getattr - retrieve file metadata
 723  * @mnt: mount information
 724  * @dentry: file to get attributes on
 725  * @stat: metadata structure to populate
 726  *
 727  */
 728
 729 static int
 730 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 731                  struct kstat *stat)
 732 {
 733         int err;
 734         struct v9fs_session_info *v9ses;
 735         struct p9_fid *fid;
 736         struct p9_stat *st;
 737
 738         P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 739         err = -EPERM;
 740         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 741         if (v9ses->cache == CACHE_LOOSE)
 742                 return simple_getattr(mnt, dentry, stat);
 743
 744         fid = v9fs_fid_lookup(dentry);
 745         if (IS_ERR(fid))
 746                 return PTR_ERR(fid);
 747
 748         st = p9_client_stat(fid);
 749         if (IS_ERR(st))
 750                 return PTR_ERR(st);
 751
 752         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
 753                 generic_fillattr(dentry->d_inode, stat);
 754
 755         kfree(st);
 756         return 0;
 757 }
 758
 759 /**
 760  * v9fs_vfs_setattr - set file metadata
 761  * @dentry: file whose metadata to set
 762  * @iattr: metadata assignment structure
 763  *
 764  */
 765
 766 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 767 {
 768         int retval;
 769         struct v9fs_session_info *v9ses;
 770         struct p9_fid *fid;
 771         struct p9_wstat wstat;
 772
 773         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 774         retval = -EPERM;
 775         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 776         fid = v9fs_fid_lookup(dentry);
 777         if(IS_ERR(fid))
 778                 return PTR_ERR(fid);
 779
 780         v9fs_blank_wstat(&wstat);
 781         if (iattr->ia_valid & ATTR_MODE)
 782                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 783
 784         if (iattr->ia_valid & ATTR_MTIME)
 785                 wstat.mtime = iattr->ia_mtime.tv_sec;
 786
 787         if (iattr->ia_valid & ATTR_ATIME)
 788                 wstat.atime = iattr->ia_atime.tv_sec;
 789
 790         if (iattr->ia_valid & ATTR_SIZE)
 791                 wstat.length = iattr->ia_size;
 792
 793         if (v9fs_extended(v9ses)) {
 794                 if (iattr->ia_valid & ATTR_UID)
 795                         wstat.n_uid = iattr->ia_uid;
 796
 797                 if (iattr->ia_valid & ATTR_GID)
 798                         wstat.n_gid = iattr->ia_gid;
 799         }
 800
 801         retval = p9_client_wstat(fid, &wstat);
 802         if (retval >= 0)
 803                 retval = inode_setattr(dentry->d_inode, iattr);
 804
 805         return retval;
 806 }
 807
 808 /**
 809  * v9fs_stat2inode - populate an inode structure with mistat info
 810  * @stat: Plan 9 metadata (mistat) structure
 811  * @inode: inode to populate
 812  * @sb: superblock of filesystem
 813  *
 814  */
 815
 816 void
 817 v9fs_stat2inode(struct p9_stat *stat, struct inode *inode,
 818         struct super_block *sb)
 819 {
 820         int n;
 821         char ext[32];
 822         struct v9fs_session_info *v9ses = sb->s_fs_info;
 823
 824         inode->i_nlink = 1;
 825
 826         inode->i_atime.tv_sec = stat->atime;
 827         inode->i_mtime.tv_sec = stat->mtime;
 828         inode->i_ctime.tv_sec = stat->mtime;
 829
 830         inode->i_uid = v9ses->dfltuid;
 831         inode->i_gid = v9ses->dfltgid;
 832
 833         if (v9fs_extended(v9ses)) {
 834                 inode->i_uid = stat->n_uid;
 835                 inode->i_gid = stat->n_gid;
 836         }
 837
 838         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 839         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 840                 char type = 0;
 841                 int major = -1;
 842                 int minor = -1;
 843
 844                 n = stat->extension.len;
 845                 if (n > sizeof(ext)-1)
 846                         n = sizeof(ext)-1;
 847                 memmove(ext, stat->extension.str, n);
 848                 ext[n] = 0;
 849                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 850                 switch (type) {
 851                 case 'c':
 852                         inode->i_mode &= ~S_IFBLK;
 853                         inode->i_mode |= S_IFCHR;
 854                         break;
 855                 case 'b':
 856                         break;
 857                 default:
 858                         P9_DPRINTK(P9_DEBUG_ERROR,
 859                                 "Unknown special type %c (%.*s)\n", type,
 860                                 stat->extension.len, stat->extension.str);
 861                 };
 862                 inode->i_rdev = MKDEV(major, minor);
 863         } else
 864                 inode->i_rdev = 0;
 865
 866         inode->i_size = stat->length;
 867
 868         /* not real number of blocks, but 512 byte ones ... */
 869         inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
 870 }
 871
 872 /**
 873  * v9fs_qid2ino - convert qid into inode number
 874  * @qid: qid to hash
 875  *
 876  * BUG: potential for inode number collisions?
 877  */
 878
 879 ino_t v9fs_qid2ino(struct p9_qid *qid)
 880 {
 881         u64 path = qid->path + 2;
 882         ino_t i = 0;
 883
 884         if (sizeof(ino_t) == sizeof(path))
 885                 memcpy(&i, &path, sizeof(ino_t));
 886         else
 887                 i = (ino_t) (path ^ (path >> 32));
 888
 889         return i;
 890 }
 891
 892 /**
 893  * v9fs_readlink - read a symlink's location (internal version)
 894  * @dentry: dentry for symlink
 895  * @buffer: buffer to load symlink location into
 896  * @buflen: length of buffer
 897  *
 898  */
 899
 900 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 901 {
 902         int retval;
 903
 904         struct v9fs_session_info *v9ses;
 905         struct p9_fid *fid;
 906         struct p9_stat *st;
 907
 908         P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
 909         retval = -EPERM;
 910         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 911         fid = v9fs_fid_lookup(dentry);
 912         if (IS_ERR(fid))
 913                 return PTR_ERR(fid);
 914
 915         if (!v9fs_extended(v9ses))
 916                 return -EBADF;
 917
 918         st = p9_client_stat(fid);
 919         if (IS_ERR(st))
 920                 return PTR_ERR(st);
 921
 922         if (!(st->mode & P9_DMSYMLINK)) {
 923                 retval = -EINVAL;
 924                 goto done;
 925         }
 926
 927         /* copy extension buffer into buffer */
 928         if (st->extension.len < buflen)
 929                 buflen = st->extension.len + 1;
 930
 931         memmove(buffer, st->extension.str, buflen - 1);
 932         buffer[buflen-1] = 0;
 933
 934         P9_DPRINTK(P9_DEBUG_VFS,
 935                 "%s -> %.*s (%s)\n", dentry->d_name.name, st->extension.len,
 936                 st->extension.str, buffer);
 937
 938         retval = buflen;
 939
 940 done:
 941         kfree(st);
 942         return retval;
 943 }
 944
 945 /**
 946  * v9fs_vfs_readlink - read a symlink's location
 947  * @dentry: dentry for symlink
 948  * @buffer: buffer to load symlink location into
 949  * @buflen: length of buffer
 950  *
 951  */
 952
 953 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
 954                              int buflen)
 955 {
 956         int retval;
 957         int ret;
 958         char *link = __getname();
 959
 960         if (unlikely(!link))
 961                 return -ENOMEM;
 962
 963         if (buflen > PATH_MAX)
 964                 buflen = PATH_MAX;
 965
 966         P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
 967
 968         retval = v9fs_readlink(dentry, link, buflen);
 969
 970         if (retval > 0) {
 971                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
 972                         P9_DPRINTK(P9_DEBUG_ERROR,
 973                                         "problem copying to user: %d\n", ret);
 974                         retval = ret;
 975                 }
 976         }
 977
 978         __putname(link);
 979         return retval;
 980 }
 981
 982 /**
 983  * v9fs_vfs_follow_link - follow a symlink path
 984  * @dentry: dentry for symlink
 985  * @nd: nameidata
 986  *
 987  */
 988
 989 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 990 {
 991         int len = 0;
 992         char *link = __getname();
 993
 994         P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
 995
 996         if (!link)
 997                 link = ERR_PTR(-ENOMEM);
 998         else {
 999                 len = v9fs_readlink(dentry, link, PATH_MAX);
1000
1001                 if (len < 0) {
1002                         __putname(link);
1003                         link = ERR_PTR(len);
1004                 } else
1005                         link[len] = 0;
1006         }
1007         nd_set_link(nd, link);
1008
1009         return NULL;
1010 }
1011
1012 /**
1013  * v9fs_vfs_put_link - release a symlink path
1014  * @dentry: dentry for symlink
1015  * @nd: nameidata
1016  * @p: unused
1017  *
1018  */
1019
1020 static void
1021 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1022 {
1023         char *s = nd_get_link(nd);
1024
1025         P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1026         if (!IS_ERR(s))
1027                 __putname(s);
1028 }
1029
1030 /**
1031  * v9fs_vfs_mkspecial - create a special file
1032  * @dir: inode to create special file in
1033  * @dentry: dentry to create
1034  * @mode: mode to create special file
1035  * @extension: 9p2000.u format extension string representing special file
1036  *
1037  */
1038
1039 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1040         int mode, const char *extension)
1041 {
1042         u32 perm;
1043         struct v9fs_session_info *v9ses;
1044         struct p9_fid *fid;
1045
1046         v9ses = v9fs_inode2v9ses(dir);
1047         if (!v9fs_extended(v9ses)) {
1048                 P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1049                 return -EPERM;
1050         }
1051
1052         perm = unixmode2p9mode(v9ses, mode);
1053         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1054                                                                 P9_OREAD);
1055         if (IS_ERR(fid))
1056                 return PTR_ERR(fid);
1057
1058         p9_client_clunk(fid);
1059         return 0;
1060 }
1061
1062 /**
1063  * v9fs_vfs_symlink - helper function to create symlinks
1064  * @dir: directory inode containing symlink
1065  * @dentry: dentry for symlink
1066  * @symname: symlink data
1067  *
1068  * See Also: 9P2000.u RFC for more information
1069  *
1070  */
1071
1072 static int
1073 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1074 {
1075         P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1076                                         dentry->d_name.name, symname);
1077
1078         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1079 }
1080
1081 /**
1082  * v9fs_vfs_link - create a hardlink
1083  * @old_dentry: dentry for file to link to
1084  * @dir: inode destination for new link
1085  * @dentry: dentry for link
1086  *
1087  */
1088
1089 static int
1090 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1091               struct dentry *dentry)
1092 {
1093         int retval;
1094         struct p9_fid *oldfid;
1095         char *name;
1096
1097         P9_DPRINTK(P9_DEBUG_VFS,
1098                 " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1099                 old_dentry->d_name.name);
1100
1101         oldfid = v9fs_fid_clone(old_dentry);
1102         if (IS_ERR(oldfid))
1103                 return PTR_ERR(oldfid);
1104
1105         name = __getname();
1106         if (unlikely(!name)) {
1107                 retval = -ENOMEM;
1108                 goto clunk_fid;
1109         }
1110
1111         sprintf(name, "%d\n", oldfid->fid);
1112         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1113         __putname(name);
1114
1115 clunk_fid:
1116         p9_client_clunk(oldfid);
1117         return retval;
1118 }
1119
1120 /**
1121  * v9fs_vfs_mknod - create a special file
1122  * @dir: inode destination for new link
1123  * @dentry: dentry for file
1124  * @mode: mode for creation
1125  * @rdev: device associated with special file
1126  *
1127  */
1128
1129 static int
1130 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1131 {
1132         int retval;
1133         char *name;
1134
1135         P9_DPRINTK(P9_DEBUG_VFS,
1136                 " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1137                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1138
1139         if (!new_valid_dev(rdev))
1140                 return -EINVAL;
1141
1142         name = __getname();
1143         if (!name)
1144                 return -ENOMEM;
1145         /* build extension */
1146         if (S_ISBLK(mode))
1147                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1148         else if (S_ISCHR(mode))
1149                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1150         else if (S_ISFIFO(mode))
1151                 *name = 0;
1152         else {
1153                 __putname(name);
1154                 return -EINVAL;
1155         }
1156
1157         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1158         __putname(name);
1159
1160         return retval;
1161 }
1162
1163 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1164         .create = v9fs_vfs_create,
1165         .lookup = v9fs_vfs_lookup,
1166         .symlink = v9fs_vfs_symlink,
1167         .link = v9fs_vfs_link,
1168         .unlink = v9fs_vfs_unlink,
1169         .mkdir = v9fs_vfs_mkdir,
1170         .rmdir = v9fs_vfs_rmdir,
1171         .mknod = v9fs_vfs_mknod,
1172         .rename = v9fs_vfs_rename,
1173         .readlink = v9fs_vfs_readlink,
1174         .getattr = v9fs_vfs_getattr,
1175         .setattr = v9fs_vfs_setattr,
1176 };
1177
1178 static const struct inode_operations v9fs_dir_inode_operations = {
1179         .create = v9fs_vfs_create,
1180         .lookup = v9fs_vfs_lookup,
1181         .unlink = v9fs_vfs_unlink,
1182         .mkdir = v9fs_vfs_mkdir,
1183         .rmdir = v9fs_vfs_rmdir,
1184         .mknod = v9fs_vfs_mknod,
1185         .rename = v9fs_vfs_rename,
1186         .getattr = v9fs_vfs_getattr,
1187         .setattr = v9fs_vfs_setattr,
1188 };
1189
1190 static const struct inode_operations v9fs_file_inode_operations = {
1191         .getattr = v9fs_vfs_getattr,
1192         .setattr = v9fs_vfs_setattr,
1193 };
1194
1195 static const struct inode_operations v9fs_symlink_inode_operations = {
1196         .readlink = v9fs_vfs_readlink,
1197         .follow_link = v9fs_vfs_follow_link,
1198         .put_link = v9fs_vfs_put_link,
1199         .getattr = v9fs_vfs_getattr,
1200         .setattr = v9fs_vfs_setattr,
1201 };