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  * @v9ses: 9P session info (for determining extended mode)
 175  * @wstat: structure to initialize
 176  *
 177  */
 178
 179 static void
 180 v9fs_blank_wstat(struct p9_wstat *wstat)
 181 {
 182         wstat->type = ~0;
 183         wstat->dev = ~0;
 184         wstat->qid.type = ~0;
 185         wstat->qid.version = ~0;
 186         *((long long *)&wstat->qid.path) = ~0;
 187         wstat->mode = ~0;
 188         wstat->atime = ~0;
 189         wstat->mtime = ~0;
 190         wstat->length = ~0;
 191         wstat->name = NULL;
 192         wstat->uid = NULL;
 193         wstat->gid = NULL;
 194         wstat->muid = NULL;
 195         wstat->n_uid = ~0;
 196         wstat->n_gid = ~0;
 197         wstat->n_muid = ~0;
 198         wstat->extension = NULL;
 199 }
 200
 201 /**
 202  * v9fs_get_inode - helper function to setup an inode
 203  * @sb: superblock
 204  * @mode: mode to setup inode with
 205  *
 206  */
 207
 208 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 209 {
 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                 inode->i_mode = mode;
 218                 inode->i_uid = current->fsuid;
 219                 inode->i_gid = current->fsgid;
 220                 inode->i_blocks = 0;
 221                 inode->i_rdev = 0;
 222                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 223                 inode->i_mapping->a_ops = &v9fs_addr_operations;
 224
 225                 switch (mode & S_IFMT) {
 226                 case S_IFIFO:
 227                 case S_IFBLK:
 228                 case S_IFCHR:
 229                 case S_IFSOCK:
 230                         if (!v9fs_extended(v9ses)) {
 231                                 P9_DPRINTK(P9_DEBUG_ERROR,
 232                                       "special files without extended mode\n");
 233                                 return ERR_PTR(-EINVAL);
 234                         }
 235                         init_special_inode(inode, inode->i_mode,
 236                                            inode->i_rdev);
 237                         break;
 238                 case S_IFREG:
 239                         inode->i_op = &v9fs_file_inode_operations;
 240                         inode->i_fop = &v9fs_file_operations;
 241                         break;
 242                 case S_IFLNK:
 243                         if (!v9fs_extended(v9ses)) {
 244                                 P9_DPRINTK(P9_DEBUG_ERROR,
 245                                         "extended modes used w/o 9P2000.u\n");
 246                                 return ERR_PTR(-EINVAL);
 247                         }
 248                         inode->i_op = &v9fs_symlink_inode_operations;
 249                         break;
 250                 case S_IFDIR:
 251                         inc_nlink(inode);
 252                         if (v9fs_extended(v9ses))
 253                                 inode->i_op = &v9fs_dir_inode_operations_ext;
 254                         else
 255                                 inode->i_op = &v9fs_dir_inode_operations;
 256                         inode->i_fop = &v9fs_dir_operations;
 257                         break;
 258                 default:
 259                         P9_DPRINTK(P9_DEBUG_ERROR,
 260                                 "BAD mode 0x%x S_IFMT 0x%x\n",
 261                                 mode, mode & S_IFMT);
 262                         return ERR_PTR(-EINVAL);
 263                 }
 264         } else {
 265                 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
 266                 return ERR_PTR(-ENOMEM);
 267         }
 268         return inode;
 269 }
 270
 271 /*
 272 static struct v9fs_fid*
 273 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 274 {
 275         int err;
 276         int nfid;
 277         struct v9fs_fid *ret;
 278         struct v9fs_fcall *fcall;
 279
 280         nfid = v9fs_get_idpool(&v9ses->fidpool);
 281         if (nfid < 0) {
 282                 eprintk(KERN_WARNING, "no free fids available\n");
 283                 return ERR_PTR(-ENOSPC);
 284         }
 285
 286         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 287                 &fcall);
 288
 289         if (err < 0) {
 290                 if (fcall && fcall->id == RWALK)
 291                         goto clunk_fid;
 292
 293                 PRINT_FCALL_ERROR("walk error", fcall);
 294                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 295                 goto error;
 296         }
 297
 298         kfree(fcall);
 299         fcall = NULL;
 300         ret = v9fs_fid_create(v9ses, nfid);
 301         if (!ret) {
 302                 err = -ENOMEM;
 303                 goto clunk_fid;
 304         }
 305
 306         err = v9fs_fid_insert(ret, dentry);
 307         if (err < 0) {
 308                 v9fs_fid_destroy(ret);
 309                 goto clunk_fid;
 310         }
 311
 312         return ret;
 313
 314 clunk_fid:
 315         v9fs_t_clunk(v9ses, nfid);
 316
 317 error:
 318         kfree(fcall);
 319         return ERR_PTR(err);
 320 }
 321 */
 322
 323 /**
 324  * v9fs_inode_from_fid - populate an inode by issuing a attribute request
 325  * @v9ses: session information
 326  * @fid: fid to issue attribute request for
 327  * @sb: superblock on which to create inode
 328  *
 329  */
 330
 331 static struct inode *
 332 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 333         struct super_block *sb)
 334 {
 335         int err, umode;
 336         struct inode *ret;
 337         struct p9_stat *st;
 338
 339         ret = NULL;
 340         st = p9_client_stat(fid);
 341         if (IS_ERR(st)) {
 342                 err = PTR_ERR(st);
 343                 st = NULL;
 344                 goto error;
 345         }
 346
 347         umode = p9mode2unixmode(v9ses, st->mode);
 348         ret = v9fs_get_inode(sb, umode);
 349         if (IS_ERR(ret)) {
 350                 err = PTR_ERR(ret);
 351                 ret = NULL;
 352                 goto error;
 353         }
 354
 355         v9fs_stat2inode(st, ret, sb);
 356         ret->i_ino = v9fs_qid2ino(&st->qid);
 357         kfree(st);
 358         return ret;
 359
 360 error:
 361         kfree(st);
 362         if (ret)
 363                 iput(ret);
 364
 365         return ERR_PTR(err);
 366 }
 367
 368 /**
 369  * v9fs_remove - helper function to remove files and directories
 370  * @dir: directory inode that is being deleted
 371  * @file:  dentry that is being deleted
 372  * @rmdir: removing a directory
 373  *
 374  */
 375
 376 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 377 {
 378         struct inode *file_inode;
 379         struct v9fs_session_info *v9ses;
 380         struct p9_fid *v9fid;
 381
 382         P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 383                 rmdir);
 384
 385         file_inode = file->d_inode;
 386         v9ses = v9fs_inode2v9ses(file_inode);
 387         v9fid = v9fs_fid_clone(file);
 388         if (IS_ERR(v9fid))
 389                 return PTR_ERR(v9fid);
 390
 391         return p9_client_remove(v9fid);
 392 }
 393
 394 static int
 395 v9fs_open_created(struct inode *inode, struct file *file)
 396 {
 397         return 0;
 398 }
 399
 400
 401 /**
 402  * v9fs_create - Create a file
 403  * @v9ses: session information
 404  * @dir: directory that dentry is being created in
 405  * @dentry:  dentry that is being created
 406  * @perm: create permissions
 407  * @mode: open mode
 408  * @extension: 9p2000.u extension string to support devices, etc.
 409  *
 410  */
 411 static struct p9_fid *
 412 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 413                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 414 {
 415         int err;
 416         char *name;
 417         struct p9_fid *dfid, *ofid, *fid;
 418         struct inode *inode;
 419
 420         err = 0;
 421         ofid = NULL;
 422         fid = NULL;
 423         name = (char *) dentry->d_name.name;
 424         dfid = v9fs_fid_clone(dentry->d_parent);
 425         if (IS_ERR(dfid)) {
 426                 err = PTR_ERR(dfid);
 427                 dfid = NULL;
 428                 goto error;
 429         }
 430
 431         /* clone a fid to use for creation */
 432         ofid = p9_client_walk(dfid, 0, NULL, 1);
 433         if (IS_ERR(ofid)) {
 434                 err = PTR_ERR(ofid);
 435                 ofid = NULL;
 436                 goto error;
 437         }
 438
 439         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 440         if (err < 0)
 441                 goto error;
 442
 443         /* now walk from the parent so we can get unopened fid */
 444         fid = p9_client_walk(dfid, 1, &name, 0);
 445         if (IS_ERR(fid)) {
 446                 err = PTR_ERR(fid);
 447                 fid = NULL;
 448                 goto error;
 449         } else
 450                 dfid = NULL;
 451
 452         /* instantiate inode and assign the unopened fid to the dentry */
 453         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 454         if (IS_ERR(inode)) {
 455                 err = PTR_ERR(inode);
 456                 goto error;
 457         }
 458
 459         if (v9ses->cache)
 460                 dentry->d_op = &v9fs_cached_dentry_operations;
 461         else
 462                 dentry->d_op = &v9fs_dentry_operations;
 463
 464         d_instantiate(dentry, inode);
 465         v9fs_fid_add(dentry, fid);
 466         return ofid;
 467
 468 error:
 469         if (dfid)
 470                 p9_client_clunk(dfid);
 471
 472         if (ofid)
 473                 p9_client_clunk(ofid);
 474
 475         if (fid)
 476                 p9_client_clunk(fid);
 477
 478         return ERR_PTR(err);
 479 }
 480
 481 /**
 482  * v9fs_vfs_create - VFS hook to create files
 483  * @dir: directory inode that is being created
 484  * @dentry:  dentry that is being deleted
 485  * @mode: create permissions
 486  * @nd: path information
 487  *
 488  */
 489
 490 static int
 491 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 492                 struct nameidata *nd)
 493 {
 494         int err;
 495         u32 perm;
 496         int flags;
 497         struct v9fs_session_info *v9ses;
 498         struct p9_fid *fid;
 499         struct file *filp;
 500
 501         err = 0;
 502         fid = NULL;
 503         v9ses = v9fs_inode2v9ses(dir);
 504         perm = unixmode2p9mode(v9ses, mode);
 505         if (nd && nd->flags & LOOKUP_OPEN)
 506                 flags = nd->intent.open.flags - 1;
 507         else
 508                 flags = O_RDWR;
 509
 510         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 511                                 v9fs_uflags2omode(flags, v9fs_extended(v9ses)));
 512         if (IS_ERR(fid)) {
 513                 err = PTR_ERR(fid);
 514                 fid = NULL;
 515                 goto error;
 516         }
 517
 518         /* if we are opening a file, assign the open fid to the file */
 519         if (nd && nd->flags & LOOKUP_OPEN) {
 520                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 521                 if (IS_ERR(filp)) {
 522                         err = PTR_ERR(filp);
 523                         goto error;
 524                 }
 525
 526                 filp->private_data = fid;
 527         } else
 528                 p9_client_clunk(fid);
 529
 530         return 0;
 531
 532 error:
 533         if (fid)
 534                 p9_client_clunk(fid);
 535
 536         return err;
 537 }
 538
 539 /**
 540  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 541  * @dir:  inode that is being unlinked
 542  * @dentry: dentry that is being unlinked
 543  * @mode: mode for new directory
 544  *
 545  */
 546
 547 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 548 {
 549         int err;
 550         u32 perm;
 551         struct v9fs_session_info *v9ses;
 552         struct p9_fid *fid;
 553
 554         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 555         err = 0;
 556         v9ses = v9fs_inode2v9ses(dir);
 557         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 558         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 559         if (IS_ERR(fid)) {
 560                 err = PTR_ERR(fid);
 561                 fid = NULL;
 562         }
 563
 564         if (fid)
 565                 p9_client_clunk(fid);
 566
 567         return err;
 568 }
 569
 570 /**
 571  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 572  * @dir:  inode that is being walked from
 573  * @dentry: dentry that is being walked to?
 574  * @nameidata: path data
 575  *
 576  */
 577
 578 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 579                                       struct nameidata *nameidata)
 580 {
 581         struct super_block *sb;
 582         struct v9fs_session_info *v9ses;
 583         struct p9_fid *dfid, *fid;
 584         struct inode *inode;
 585         char *name;
 586         int result = 0;
 587
 588         P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 589                 dir, dentry->d_name.name, dentry, nameidata);
 590
 591         sb = dir->i_sb;
 592         v9ses = v9fs_inode2v9ses(dir);
 593         dfid = v9fs_fid_lookup(dentry->d_parent);
 594         if (IS_ERR(dfid))
 595                 return ERR_CAST(dfid);
 596
 597         name = (char *) dentry->d_name.name;
 598         fid = p9_client_walk(dfid, 1, &name, 1);
 599         if (IS_ERR(fid)) {
 600                 result = PTR_ERR(fid);
 601                 if (result == -ENOENT) {
 602                         d_add(dentry, NULL);
 603                         return NULL;
 604                 }
 605
 606                 return ERR_PTR(result);
 607         }
 608
 609         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 610         if (IS_ERR(inode)) {
 611                 result = PTR_ERR(inode);
 612                 inode = NULL;
 613                 goto error;
 614         }
 615
 616         result = v9fs_fid_add(dentry, fid);
 617         if (result < 0)
 618                 goto error;
 619
 620         if ((fid->qid.version) && (v9ses->cache))
 621                 dentry->d_op = &v9fs_cached_dentry_operations;
 622         else
 623                 dentry->d_op = &v9fs_dentry_operations;
 624
 625         d_add(dentry, inode);
 626         return NULL;
 627
 628 error:
 629         p9_client_clunk(fid);
 630
 631         return ERR_PTR(result);
 632 }
 633
 634 /**
 635  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 636  * @i:  inode that is being unlinked
 637  * @d: dentry that is being unlinked
 638  *
 639  */
 640
 641 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 642 {
 643         return v9fs_remove(i, d, 0);
 644 }
 645
 646 /**
 647  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 648  * @i:  inode that is being unlinked
 649  * @d: dentry that is being unlinked
 650  *
 651  */
 652
 653 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 654 {
 655         return v9fs_remove(i, d, 1);
 656 }
 657
 658 /**
 659  * v9fs_vfs_rename - VFS hook to rename an inode
 660  * @old_dir:  old dir inode
 661  * @old_dentry: old dentry
 662  * @new_dir: new dir inode
 663  * @new_dentry: new dentry
 664  *
 665  */
 666
 667 static int
 668 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 669                 struct inode *new_dir, struct dentry *new_dentry)
 670 {
 671         struct inode *old_inode;
 672         struct v9fs_session_info *v9ses;
 673         struct p9_fid *oldfid;
 674         struct p9_fid *olddirfid;
 675         struct p9_fid *newdirfid;
 676         struct p9_wstat wstat;
 677         int retval;
 678
 679         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 680         retval = 0;
 681         old_inode = old_dentry->d_inode;
 682         v9ses = v9fs_inode2v9ses(old_inode);
 683         oldfid = v9fs_fid_lookup(old_dentry);
 684         if (IS_ERR(oldfid))
 685                 return PTR_ERR(oldfid);
 686
 687         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 688         if (IS_ERR(olddirfid)) {
 689                 retval = PTR_ERR(olddirfid);
 690                 goto done;
 691         }
 692
 693         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 694         if (IS_ERR(newdirfid)) {
 695                 retval = PTR_ERR(newdirfid);
 696                 goto clunk_olddir;
 697         }
 698
 699         /* 9P can only handle file rename in the same directory */
 700         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 701                 P9_DPRINTK(P9_DEBUG_ERROR,
 702                                 "old dir and new dir are different\n");
 703                 retval = -EXDEV;
 704                 goto clunk_newdir;
 705         }
 706
 707         v9fs_blank_wstat(&wstat);
 708         wstat.muid = v9ses->uname;
 709         wstat.name = (char *) new_dentry->d_name.name;
 710         retval = p9_client_wstat(oldfid, &wstat);
 711
 712 clunk_newdir:
 713         p9_client_clunk(newdirfid);
 714
 715 clunk_olddir:
 716         p9_client_clunk(olddirfid);
 717
 718 done:
 719         return retval;
 720 }
 721
 722 /**
 723  * v9fs_vfs_getattr - retrieve file metadata
 724  * @mnt: mount information
 725  * @dentry: file to get attributes on
 726  * @stat: metadata structure to populate
 727  *
 728  */
 729
 730 static int
 731 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 732                  struct kstat *stat)
 733 {
 734         int err;
 735         struct v9fs_session_info *v9ses;
 736         struct p9_fid *fid;
 737         struct p9_stat *st;
 738
 739         P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 740         err = -EPERM;
 741         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 742         if (v9ses->cache == CACHE_LOOSE)
 743                 return simple_getattr(mnt, dentry, stat);
 744
 745         fid = v9fs_fid_lookup(dentry);
 746         if (IS_ERR(fid))
 747                 return PTR_ERR(fid);
 748
 749         st = p9_client_stat(fid);
 750         if (IS_ERR(st))
 751                 return PTR_ERR(st);
 752
 753         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
 754                 generic_fillattr(dentry->d_inode, stat);
 755
 756         kfree(st);
 757         return 0;
 758 }
 759
 760 /**
 761  * v9fs_vfs_setattr - set file metadata
 762  * @dentry: file whose metadata to set
 763  * @iattr: metadata assignment structure
 764  *
 765  */
 766
 767 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 768 {
 769         int retval;
 770         struct v9fs_session_info *v9ses;
 771         struct p9_fid *fid;
 772         struct p9_wstat wstat;
 773
 774         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 775         retval = -EPERM;
 776         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 777         fid = v9fs_fid_lookup(dentry);
 778         if(IS_ERR(fid))
 779                 return PTR_ERR(fid);
 780
 781         v9fs_blank_wstat(&wstat);
 782         if (iattr->ia_valid & ATTR_MODE)
 783                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 784
 785         if (iattr->ia_valid & ATTR_MTIME)
 786                 wstat.mtime = iattr->ia_mtime.tv_sec;
 787
 788         if (iattr->ia_valid & ATTR_ATIME)
 789                 wstat.atime = iattr->ia_atime.tv_sec;
 790
 791         if (iattr->ia_valid & ATTR_SIZE)
 792                 wstat.length = iattr->ia_size;
 793
 794         if (v9fs_extended(v9ses)) {
 795                 if (iattr->ia_valid & ATTR_UID)
 796                         wstat.n_uid = iattr->ia_uid;
 797
 798                 if (iattr->ia_valid & ATTR_GID)
 799                         wstat.n_gid = iattr->ia_gid;
 800         }
 801
 802         retval = p9_client_wstat(fid, &wstat);
 803         if (retval >= 0)
 804                 retval = inode_setattr(dentry->d_inode, iattr);
 805
 806         return retval;
 807 }
 808
 809 /**
 810  * v9fs_stat2inode - populate an inode structure with mistat info
 811  * @stat: Plan 9 metadata (mistat) structure
 812  * @inode: inode to populate
 813  * @sb: superblock of filesystem
 814  *
 815  */
 816
 817 void
 818 v9fs_stat2inode(struct p9_stat *stat, struct inode *inode,
 819         struct super_block *sb)
 820 {
 821         int n;
 822         char ext[32];
 823         struct v9fs_session_info *v9ses = sb->s_fs_info;
 824
 825         inode->i_nlink = 1;
 826
 827         inode->i_atime.tv_sec = stat->atime;
 828         inode->i_mtime.tv_sec = stat->mtime;
 829         inode->i_ctime.tv_sec = stat->mtime;
 830
 831         inode->i_uid = v9ses->dfltuid;
 832         inode->i_gid = v9ses->dfltgid;
 833
 834         if (v9fs_extended(v9ses)) {
 835                 inode->i_uid = stat->n_uid;
 836                 inode->i_gid = stat->n_gid;
 837         }
 838
 839         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 840         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 841                 char type = 0;
 842                 int major = -1;
 843                 int minor = -1;
 844
 845                 n = stat->extension.len;
 846                 if (n > sizeof(ext)-1)
 847                         n = sizeof(ext)-1;
 848                 memmove(ext, stat->extension.str, n);
 849                 ext[n] = 0;
 850                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 851                 switch (type) {
 852                 case 'c':
 853                         inode->i_mode &= ~S_IFBLK;
 854                         inode->i_mode |= S_IFCHR;
 855                         break;
 856                 case 'b':
 857                         break;
 858                 default:
 859                         P9_DPRINTK(P9_DEBUG_ERROR,
 860                                 "Unknown special type %c (%.*s)\n", type,
 861                                 stat->extension.len, stat->extension.str);
 862                 };
 863                 inode->i_rdev = MKDEV(major, minor);
 864         } else
 865                 inode->i_rdev = 0;
 866
 867         inode->i_size = stat->length;
 868
 869         /* not real number of blocks, but 512 byte ones ... */
 870         inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
 871 }
 872
 873 /**
 874  * v9fs_qid2ino - convert qid into inode number
 875  * @qid: qid to hash
 876  *
 877  * BUG: potential for inode number collisions?
 878  */
 879
 880 ino_t v9fs_qid2ino(struct p9_qid *qid)
 881 {
 882         u64 path = qid->path + 2;
 883         ino_t i = 0;
 884
 885         if (sizeof(ino_t) == sizeof(path))
 886                 memcpy(&i, &path, sizeof(ino_t));
 887         else
 888                 i = (ino_t) (path ^ (path >> 32));
 889
 890         return i;
 891 }
 892
 893 /**
 894  * v9fs_readlink - read a symlink's location (internal version)
 895  * @dentry: dentry for symlink
 896  * @buffer: buffer to load symlink location into
 897  * @buflen: length of buffer
 898  *
 899  */
 900
 901 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 902 {
 903         int retval;
 904
 905         struct v9fs_session_info *v9ses;
 906         struct p9_fid *fid;
 907         struct p9_stat *st;
 908
 909         P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
 910         retval = -EPERM;
 911         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 912         fid = v9fs_fid_lookup(dentry);
 913         if (IS_ERR(fid))
 914                 return PTR_ERR(fid);
 915
 916         if (!v9fs_extended(v9ses))
 917                 return -EBADF;
 918
 919         st = p9_client_stat(fid);
 920         if (IS_ERR(st))
 921                 return PTR_ERR(st);
 922
 923         if (!(st->mode & P9_DMSYMLINK)) {
 924                 retval = -EINVAL;
 925                 goto done;
 926         }
 927
 928         /* copy extension buffer into buffer */
 929         if (st->extension.len < buflen)
 930                 buflen = st->extension.len + 1;
 931
 932         memmove(buffer, st->extension.str, buflen - 1);
 933         buffer[buflen-1] = 0;
 934
 935         P9_DPRINTK(P9_DEBUG_VFS,
 936                 "%s -> %.*s (%s)\n", dentry->d_name.name, st->extension.len,
 937                 st->extension.str, buffer);
 938
 939         retval = buflen;
 940
 941 done:
 942         kfree(st);
 943         return retval;
 944 }
 945
 946 /**
 947  * v9fs_vfs_readlink - read a symlink's location
 948  * @dentry: dentry for symlink
 949  * @buffer: buffer to load symlink location into
 950  * @buflen: length of buffer
 951  *
 952  */
 953
 954 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
 955                              int buflen)
 956 {
 957         int retval;
 958         int ret;
 959         char *link = __getname();
 960
 961         if (unlikely(!link))
 962                 return -ENOMEM;
 963
 964         if (buflen > PATH_MAX)
 965                 buflen = PATH_MAX;
 966
 967         P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
 968
 969         retval = v9fs_readlink(dentry, link, buflen);
 970
 971         if (retval > 0) {
 972                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
 973                         P9_DPRINTK(P9_DEBUG_ERROR,
 974                                         "problem copying to user: %d\n", ret);
 975                         retval = ret;
 976                 }
 977         }
 978
 979         __putname(link);
 980         return retval;
 981 }
 982
 983 /**
 984  * v9fs_vfs_follow_link - follow a symlink path
 985  * @dentry: dentry for symlink
 986  * @nd: nameidata
 987  *
 988  */
 989
 990 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 991 {
 992         int len = 0;
 993         char *link = __getname();
 994
 995         P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
 996
 997         if (!link)
 998                 link = ERR_PTR(-ENOMEM);
 999         else {
1000                 len = v9fs_readlink(dentry, link, PATH_MAX);
1001
1002                 if (len < 0) {
1003                         __putname(link);
1004                         link = ERR_PTR(len);
1005                 } else
1006                         link[len] = 0;
1007         }
1008         nd_set_link(nd, link);
1009
1010         return NULL;
1011 }
1012
1013 /**
1014  * v9fs_vfs_put_link - release a symlink path
1015  * @dentry: dentry for symlink
1016  * @nd: nameidata
1017  * @p: unused
1018  *
1019  */
1020
1021 static void
1022 v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1023 {
1024         char *s = nd_get_link(nd);
1025
1026         P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1027         if (!IS_ERR(s))
1028                 __putname(s);
1029 }
1030
1031 /**
1032  * v9fs_vfs_mkspecial - create a special file
1033  * @dir: inode to create special file in
1034  * @dentry: dentry to create
1035  * @mode: mode to create special file
1036  * @extension: 9p2000.u format extension string representing special file
1037  *
1038  */
1039
1040 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1041         int mode, const char *extension)
1042 {
1043         u32 perm;
1044         struct v9fs_session_info *v9ses;
1045         struct p9_fid *fid;
1046
1047         v9ses = v9fs_inode2v9ses(dir);
1048         if (!v9fs_extended(v9ses)) {
1049                 P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1050                 return -EPERM;
1051         }
1052
1053         perm = unixmode2p9mode(v9ses, mode);
1054         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1055                                                                 P9_OREAD);
1056         if (IS_ERR(fid))
1057                 return PTR_ERR(fid);
1058
1059         p9_client_clunk(fid);
1060         return 0;
1061 }
1062
1063 /**
1064  * v9fs_vfs_symlink - helper function to create symlinks
1065  * @dir: directory inode containing symlink
1066  * @dentry: dentry for symlink
1067  * @symname: symlink data
1068  *
1069  * See Also: 9P2000.u RFC for more information
1070  *
1071  */
1072
1073 static int
1074 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1075 {
1076         P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1077                                         dentry->d_name.name, symname);
1078
1079         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1080 }
1081
1082 /**
1083  * v9fs_vfs_link - create a hardlink
1084  * @old_dentry: dentry for file to link to
1085  * @dir: inode destination for new link
1086  * @dentry: dentry for link
1087  *
1088  */
1089
1090 static int
1091 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1092               struct dentry *dentry)
1093 {
1094         int retval;
1095         struct p9_fid *oldfid;
1096         char *name;
1097
1098         P9_DPRINTK(P9_DEBUG_VFS,
1099                 " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1100                 old_dentry->d_name.name);
1101
1102         oldfid = v9fs_fid_clone(old_dentry);
1103         if (IS_ERR(oldfid))
1104                 return PTR_ERR(oldfid);
1105
1106         name = __getname();
1107         if (unlikely(!name)) {
1108                 retval = -ENOMEM;
1109                 goto clunk_fid;
1110         }
1111
1112         sprintf(name, "%d\n", oldfid->fid);
1113         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1114         __putname(name);
1115
1116 clunk_fid:
1117         p9_client_clunk(oldfid);
1118         return retval;
1119 }
1120
1121 /**
1122  * v9fs_vfs_mknod - create a special file
1123  * @dir: inode destination for new link
1124  * @dentry: dentry for file
1125  * @mode: mode for creation
1126  * @rdev: device associated with special file
1127  *
1128  */
1129
1130 static int
1131 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1132 {
1133         int retval;
1134         char *name;
1135
1136         P9_DPRINTK(P9_DEBUG_VFS,
1137                 " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1138                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1139
1140         if (!new_valid_dev(rdev))
1141                 return -EINVAL;
1142
1143         name = __getname();
1144         if (!name)
1145                 return -ENOMEM;
1146         /* build extension */
1147         if (S_ISBLK(mode))
1148                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1149         else if (S_ISCHR(mode))
1150                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1151         else if (S_ISFIFO(mode))
1152                 *name = 0;
1153         else {
1154                 __putname(name);
1155                 return -EINVAL;
1156         }
1157
1158         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1159         __putname(name);
1160
1161         return retval;
1162 }
1163
1164 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1165         .create = v9fs_vfs_create,
1166         .lookup = v9fs_vfs_lookup,
1167         .symlink = v9fs_vfs_symlink,
1168         .link = v9fs_vfs_link,
1169         .unlink = v9fs_vfs_unlink,
1170         .mkdir = v9fs_vfs_mkdir,
1171         .rmdir = v9fs_vfs_rmdir,
1172         .mknod = v9fs_vfs_mknod,
1173         .rename = v9fs_vfs_rename,
1174         .readlink = v9fs_vfs_readlink,
1175         .getattr = v9fs_vfs_getattr,
1176         .setattr = v9fs_vfs_setattr,
1177 };
1178
1179 static const struct inode_operations v9fs_dir_inode_operations = {
1180         .create = v9fs_vfs_create,
1181         .lookup = v9fs_vfs_lookup,
1182         .unlink = v9fs_vfs_unlink,
1183         .mkdir = v9fs_vfs_mkdir,
1184         .rmdir = v9fs_vfs_rmdir,
1185         .mknod = v9fs_vfs_mknod,
1186         .rename = v9fs_vfs_rename,
1187         .getattr = v9fs_vfs_getattr,
1188         .setattr = v9fs_vfs_setattr,
1189 };
1190
1191 static const struct inode_operations v9fs_file_inode_operations = {
1192         .getattr = v9fs_vfs_getattr,
1193         .setattr = v9fs_vfs_setattr,
1194 };
1195
1196 static const struct inode_operations v9fs_symlink_inode_operations = {
1197         .readlink = v9fs_vfs_readlink,
1198         .follow_link = v9fs_vfs_follow_link,
1199         .put_link = v9fs_vfs_put_link,
1200         .getattr = v9fs_vfs_getattr,
1201         .setattr = v9fs_vfs_setattr,
1202 };