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/smp_lock.h>
  34 #include <linux/inet.h>
  35 #include <linux/namei.h>
  36 #include <linux/idr.h>
  37
  38 #include "debug.h"
  39 #include "v9fs.h"
  40 #include "9p.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 |= V9FS_DMDIR;
  62         if (v9ses->extended) {
  63                 if (S_ISLNK(mode))
  64                         res |= V9FS_DMSYMLINK;
  65                 if (v9ses->nodev == 0) {
  66                         if (S_ISSOCK(mode))
  67                                 res |= V9FS_DMSOCKET;
  68                         if (S_ISFIFO(mode))
  69                                 res |= V9FS_DMNAMEDPIPE;
  70                         if (S_ISBLK(mode))
  71                                 res |= V9FS_DMDEVICE;
  72                         if (S_ISCHR(mode))
  73                                 res |= V9FS_DMDEVICE;
  74                 }
  75
  76                 if ((mode & S_ISUID) == S_ISUID)
  77                         res |= V9FS_DMSETUID;
  78                 if ((mode & S_ISGID) == S_ISGID)
  79                         res |= V9FS_DMSETGID;
  80                 if ((mode & V9FS_DMLINK))
  81                         res |= V9FS_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 & V9FS_DMDIR) == V9FS_DMDIR)
 101                 res |= S_IFDIR;
 102         else if ((mode & V9FS_DMSYMLINK) && (v9ses->extended))
 103                 res |= S_IFLNK;
 104         else if ((mode & V9FS_DMSOCKET) && (v9ses->extended)
 105                  && (v9ses->nodev == 0))
 106                 res |= S_IFSOCK;
 107         else if ((mode & V9FS_DMNAMEDPIPE) && (v9ses->extended)
 108                  && (v9ses->nodev == 0))
 109                 res |= S_IFIFO;
 110         else if ((mode & V9FS_DMDEVICE) && (v9ses->extended)
 111                  && (v9ses->nodev == 0))
 112                 res |= S_IFBLK;
 113         else
 114                 res |= S_IFREG;
 115
 116         if (v9ses->extended) {
 117                 if ((mode & V9FS_DMSETUID) == V9FS_DMSETUID)
 118                         res |= S_ISUID;
 119
 120                 if ((mode & V9FS_DMSETGID) == V9FS_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 = V9FS_OREAD;
 136                 break;
 137
 138         case O_WRONLY:
 139                 ret = V9FS_OWRITE;
 140                 break;
 141
 142         case O_RDWR:
 143                 ret = V9FS_ORDWR;
 144                 break;
 145         }
 146
 147         if (uflags & O_EXCL)
 148                 ret |= V9FS_OEXCL;
 149
 150         if (uflags & O_TRUNC)
 151                 ret |= V9FS_OTRUNC;
 152
 153         if (uflags & O_APPEND)
 154                 ret |= V9FS_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 v9fs_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         dprintk(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(!v9ses->extended) {
 218                                 dprintk(DEBUG_ERROR, "special files without extended mode\n");
 219                                 return ERR_PTR(-EINVAL);
 220                         }
 221                         init_special_inode(inode, inode->i_mode,
 222                                            inode->i_rdev);
 223                         break;
 224                 case S_IFREG:
 225                         inode->i_op = &v9fs_file_inode_operations;
 226                         inode->i_fop = &v9fs_file_operations;
 227                         break;
 228                 case S_IFLNK:
 229                         if(!v9ses->extended) {
 230                                 dprintk(DEBUG_ERROR, "extended modes used w/o 9P2000.u\n");
 231                                 return ERR_PTR(-EINVAL);
 232                         }
 233                         inode->i_op = &v9fs_symlink_inode_operations;
 234                         break;
 235                 case S_IFDIR:
 236                         inc_nlink(inode);
 237                         if(v9ses->extended)
 238                                 inode->i_op = &v9fs_dir_inode_operations_ext;
 239                         else
 240                                 inode->i_op = &v9fs_dir_inode_operations;
 241                         inode->i_fop = &v9fs_dir_operations;
 242                         break;
 243                 default:
 244                         dprintk(DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
 245                                 mode, mode & S_IFMT);
 246                         return ERR_PTR(-EINVAL);
 247                 }
 248         } else {
 249                 eprintk(KERN_WARNING, "Problem allocating inode\n");
 250                 return ERR_PTR(-ENOMEM);
 251         }
 252         return inode;
 253 }
 254
 255 static int
 256 v9fs_create(struct v9fs_session_info *v9ses, u32 pfid, char *name, u32 perm,
 257         u8 mode, char *extension, u32 *fidp, struct v9fs_qid *qid, u32 *iounit)
 258 {
 259         int fid;
 260         int err;
 261         struct v9fs_fcall *fcall;
 262
 263         fid = v9fs_get_idpool(&v9ses->fidpool);
 264         if (fid < 0) {
 265                 eprintk(KERN_WARNING, "no free fids available\n");
 266                 return -ENOSPC;
 267         }
 268
 269         err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall);
 270         if (err < 0) {
 271                 PRINT_FCALL_ERROR("clone error", fcall);
 272                 if (fcall && fcall->id == RWALK)
 273                         goto clunk_fid;
 274                 else
 275                         goto put_fid;
 276         }
 277         kfree(fcall);
 278
 279         err = v9fs_t_create(v9ses, fid, name, perm, mode, extension, &fcall);
 280         if (err < 0) {
 281                 PRINT_FCALL_ERROR("create fails", fcall);
 282                 goto clunk_fid;
 283         }
 284
 285         if (iounit)
 286                 *iounit = fcall->params.rcreate.iounit;
 287
 288         if (qid)
 289                 *qid = fcall->params.rcreate.qid;
 290
 291         if (fidp)
 292                 *fidp = fid;
 293
 294         kfree(fcall);
 295         return 0;
 296
 297 clunk_fid:
 298         v9fs_t_clunk(v9ses, fid);
 299         fid = V9FS_NOFID;
 300
 301 put_fid:
 302         if (fid != V9FS_NOFID)
 303                 v9fs_put_idpool(fid, &v9ses->fidpool);
 304
 305         kfree(fcall);
 306         return err;
 307 }
 308
 309 static struct v9fs_fid*
 310 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 311 {
 312         int err;
 313         int nfid;
 314         struct v9fs_fid *ret;
 315         struct v9fs_fcall *fcall;
 316
 317         nfid = v9fs_get_idpool(&v9ses->fidpool);
 318         if (nfid < 0) {
 319                 eprintk(KERN_WARNING, "no free fids available\n");
 320                 return ERR_PTR(-ENOSPC);
 321         }
 322
 323         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 324                 &fcall);
 325
 326         if (err < 0) {
 327                 if (fcall && fcall->id == RWALK)
 328                         goto clunk_fid;
 329
 330                 PRINT_FCALL_ERROR("walk error", fcall);
 331                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 332                 goto error;
 333         }
 334
 335         kfree(fcall);
 336         fcall = NULL;
 337         ret = v9fs_fid_create(v9ses, nfid);
 338         if (!ret) {
 339                 err = -ENOMEM;
 340                 goto clunk_fid;
 341         }
 342
 343         err = v9fs_fid_insert(ret, dentry);
 344         if (err < 0) {
 345                 v9fs_fid_destroy(ret);
 346                 goto clunk_fid;
 347         }
 348
 349         return ret;
 350
 351 clunk_fid:
 352         v9fs_t_clunk(v9ses, nfid);
 353
 354 error:
 355         kfree(fcall);
 356         return ERR_PTR(err);
 357 }
 358
 359 static struct inode *
 360 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid,
 361         struct super_block *sb)
 362 {
 363         int err, umode;
 364         struct inode *ret;
 365         struct v9fs_fcall *fcall;
 366
 367         ret = NULL;
 368         err = v9fs_t_stat(v9ses, fid, &fcall);
 369         if (err) {
 370                 PRINT_FCALL_ERROR("stat error", fcall);
 371                 goto error;
 372         }
 373
 374         umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode);
 375         ret = v9fs_get_inode(sb, umode);
 376         if (IS_ERR(ret)) {
 377                 err = PTR_ERR(ret);
 378                 ret = NULL;
 379                 goto error;
 380         }
 381
 382         v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb);
 383         kfree(fcall);
 384         return ret;
 385
 386 error:
 387         kfree(fcall);
 388         if (ret)
 389                 iput(ret);
 390
 391         return ERR_PTR(err);
 392 }
 393
 394 /**
 395  * v9fs_remove - helper function to remove files and directories
 396  * @dir: directory inode that is being deleted
 397  * @file:  dentry that is being deleted
 398  * @rmdir: removing a directory
 399  *
 400  */
 401
 402 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 403 {
 404         struct v9fs_fcall *fcall = NULL;
 405         struct super_block *sb = NULL;
 406         struct v9fs_session_info *v9ses = NULL;
 407         struct v9fs_fid *v9fid = NULL;
 408         struct inode *file_inode = NULL;
 409         int fid = -1;
 410         int result = 0;
 411
 412         dprintk(DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 413                 rmdir);
 414
 415         file_inode = file->d_inode;
 416         sb = file_inode->i_sb;
 417         v9ses = v9fs_inode2v9ses(file_inode);
 418         v9fid = v9fs_fid_lookup(file);
 419         if(IS_ERR(v9fid))
 420                 return PTR_ERR(v9fid);
 421
 422         fid = v9fid->fid;
 423         if (fid < 0) {
 424                 dprintk(DEBUG_ERROR, "inode #%lu, no fid!\n",
 425                         file_inode->i_ino);
 426                 return -EBADF;
 427         }
 428
 429         result = v9fs_t_remove(v9ses, fid, &fcall);
 430         if (result < 0) {
 431                 PRINT_FCALL_ERROR("remove fails", fcall);
 432                 goto Error;
 433         }
 434
 435         v9fs_put_idpool(fid, &v9ses->fidpool);
 436         v9fs_fid_destroy(v9fid);
 437
 438 Error:
 439         kfree(fcall);
 440         return result;
 441 }
 442
 443 static int
 444 v9fs_open_created(struct inode *inode, struct file *file)
 445 {
 446         return 0;
 447 }
 448
 449 /**
 450  * v9fs_vfs_create - VFS hook to create files
 451  * @inode: directory inode that is being deleted
 452  * @dentry:  dentry that is being deleted
 453  * @mode: create permissions
 454  * @nd: path information
 455  *
 456  */
 457
 458 static int
 459 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 460                 struct nameidata *nd)
 461 {
 462         int err;
 463         u32 fid, perm, iounit;
 464         int flags;
 465         struct v9fs_session_info *v9ses;
 466         struct v9fs_fid *dfid, *vfid, *ffid;
 467         struct inode *inode;
 468         struct v9fs_qid qid;
 469         struct file *filp;
 470
 471         inode = NULL;
 472         vfid = NULL;
 473         v9ses = v9fs_inode2v9ses(dir);
 474         dfid = v9fs_fid_clone(dentry->d_parent);
 475         if(IS_ERR(dfid)) {
 476                 err = PTR_ERR(dfid);
 477                 goto error;
 478         }
 479
 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         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 487                 perm, v9fs_uflags2omode(flags), NULL, &fid, &qid, &iounit);
 488
 489         if (err)
 490                 goto clunk_dfid;
 491
 492         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 493         v9fs_fid_clunk(v9ses, dfid);
 494         if (IS_ERR(vfid)) {
 495                 err = PTR_ERR(vfid);
 496                 vfid = NULL;
 497                 goto error;
 498         }
 499
 500         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 501         if (IS_ERR(inode)) {
 502                 err = PTR_ERR(inode);
 503                 inode = NULL;
 504                 goto error;
 505         }
 506
 507         dentry->d_op = &v9fs_dentry_operations;
 508         d_instantiate(dentry, inode);
 509
 510         if (nd && nd->flags & LOOKUP_OPEN) {
 511                 ffid = v9fs_fid_create(v9ses, fid);
 512                 if (!ffid)
 513                         return -ENOMEM;
 514
 515                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 516                 if (IS_ERR(filp)) {
 517                         v9fs_fid_destroy(ffid);
 518                         return PTR_ERR(filp);
 519                 }
 520
 521                 ffid->rdir_pos = 0;
 522                 ffid->rdir_fcall = NULL;
 523                 ffid->fidopen = 1;
 524                 ffid->iounit = iounit;
 525                 ffid->filp = filp;
 526                 filp->private_data = ffid;
 527         }
 528
 529         return 0;
 530
 531 clunk_dfid:
 532         v9fs_fid_clunk(v9ses, dfid);
 533
 534 error:
 535         if (vfid)
 536                 v9fs_fid_destroy(vfid);
 537
 538         return err;
 539 }
 540
 541 /**
 542  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 543  * @inode:  inode that is being unlinked
 544  * @dentry: dentry that is being unlinked
 545  * @mode: mode for new directory
 546  *
 547  */
 548
 549 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 550 {
 551         int err;
 552         u32 fid, perm;
 553         struct v9fs_session_info *v9ses;
 554         struct v9fs_fid *dfid, *vfid;
 555         struct inode *inode;
 556
 557         inode = NULL;
 558         vfid = NULL;
 559         v9ses = v9fs_inode2v9ses(dir);
 560         dfid = v9fs_fid_clone(dentry->d_parent);
 561         if(IS_ERR(dfid)) {
 562                 err = PTR_ERR(dfid);
 563                 goto error;
 564         }
 565
 566         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 567
 568         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 569                 perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
 570
 571         if (err) {
 572                 dprintk(DEBUG_ERROR, "create error %d\n", err);
 573                 goto clean_up_dfid;
 574         }
 575
 576         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 577         if (IS_ERR(vfid)) {
 578                 err = PTR_ERR(vfid);
 579                 vfid = NULL;
 580                 goto clean_up_dfid;
 581         }
 582
 583         v9fs_fid_clunk(v9ses, dfid);
 584         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 585         if (IS_ERR(inode)) {
 586                 err = PTR_ERR(inode);
 587                 inode = NULL;
 588                 v9fs_fid_destroy(vfid);
 589                 goto error;
 590         }
 591
 592         dentry->d_op = &v9fs_dentry_operations;
 593         d_instantiate(dentry, inode);
 594         return 0;
 595
 596 clean_up_dfid:
 597         v9fs_fid_clunk(v9ses, dfid);
 598
 599 error:
 600         return err;
 601 }
 602
 603 /**
 604  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 605  * @dir:  inode that is being walked from
 606  * @dentry: dentry that is being walked to?
 607  * @nameidata: path data
 608  *
 609  */
 610
 611 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 612                                       struct nameidata *nameidata)
 613 {
 614         struct super_block *sb;
 615         struct v9fs_session_info *v9ses;
 616         struct v9fs_fid *dirfid;
 617         struct v9fs_fid *fid;
 618         struct inode *inode;
 619         struct v9fs_fcall *fcall = NULL;
 620         int dirfidnum = -1;
 621         int newfid = -1;
 622         int result = 0;
 623
 624         dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 625                 dir, dentry->d_name.name, dentry, nameidata);
 626
 627         sb = dir->i_sb;
 628         v9ses = v9fs_inode2v9ses(dir);
 629         dentry->d_op = &v9fs_dentry_operations;
 630         dirfid = v9fs_fid_lookup(dentry->d_parent);
 631
 632         if(IS_ERR(dirfid))
 633                 return ERR_PTR(PTR_ERR(dirfid));
 634
 635         dirfidnum = dirfid->fid;
 636
 637         newfid = v9fs_get_idpool(&v9ses->fidpool);
 638         if (newfid < 0) {
 639                 eprintk(KERN_WARNING, "newfid fails!\n");
 640                 result = -ENOSPC;
 641                 goto Release_Dirfid;
 642         }
 643
 644         result = v9fs_t_walk(v9ses, dirfidnum, newfid,
 645                 (char *)dentry->d_name.name, &fcall);
 646
 647         up(&dirfid->lock);
 648
 649         if (result < 0) {
 650                 if (fcall && fcall->id == RWALK)
 651                         v9fs_t_clunk(v9ses, newfid);
 652                 else
 653                         v9fs_put_idpool(newfid, &v9ses->fidpool);
 654
 655                 if (result == -ENOENT) {
 656                         d_add(dentry, NULL);
 657                         dprintk(DEBUG_VFS,
 658                                 "Return negative dentry %p count %d\n",
 659                                 dentry, atomic_read(&dentry->d_count));
 660                         kfree(fcall);
 661                         return NULL;
 662                 }
 663                 dprintk(DEBUG_ERROR, "walk error:%d\n", result);
 664                 goto FreeFcall;
 665         }
 666         kfree(fcall);
 667
 668         result = v9fs_t_stat(v9ses, newfid, &fcall);
 669         if (result < 0) {
 670                 dprintk(DEBUG_ERROR, "stat error\n");
 671                 goto FreeFcall;
 672         }
 673
 674         inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
 675                 fcall->params.rstat.stat.mode));
 676
 677         if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
 678                 eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
 679                         PTR_ERR(inode));
 680
 681                 result = -ENOSPC;
 682                 goto FreeFcall;
 683         }
 684
 685         inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
 686
 687         fid = v9fs_fid_create(v9ses, newfid);
 688         if (fid == NULL) {
 689                 dprintk(DEBUG_ERROR, "couldn't insert\n");
 690                 result = -ENOMEM;
 691                 goto FreeFcall;
 692         }
 693
 694         result = v9fs_fid_insert(fid, dentry);
 695         if (result < 0)
 696                 goto FreeFcall;
 697
 698         fid->qid = fcall->params.rstat.stat.qid;
 699         v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
 700
 701         d_add(dentry, inode);
 702         kfree(fcall);
 703
 704         return NULL;
 705
 706 Release_Dirfid:
 707         up(&dirfid->lock);
 708
 709 FreeFcall:
 710         kfree(fcall);
 711
 712         return ERR_PTR(result);
 713 }
 714
 715 /**
 716  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 717  * @i:  inode that is being unlinked
 718  * @d: dentry that is being unlinked
 719  *
 720  */
 721
 722 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 723 {
 724         return v9fs_remove(i, d, 0);
 725 }
 726
 727 /**
 728  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 729  * @i:  inode that is being unlinked
 730  * @d: dentry that is being unlinked
 731  *
 732  */
 733
 734 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 735 {
 736         return v9fs_remove(i, d, 1);
 737 }
 738
 739 /**
 740  * v9fs_vfs_rename - VFS hook to rename an inode
 741  * @old_dir:  old dir inode
 742  * @old_dentry: old dentry
 743  * @new_dir: new dir inode
 744  * @new_dentry: new dentry
 745  *
 746  */
 747
 748 static int
 749 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 750                 struct inode *new_dir, struct dentry *new_dentry)
 751 {
 752         struct inode *old_inode = old_dentry->d_inode;
 753         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
 754         struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
 755         struct v9fs_fid *olddirfid;
 756         struct v9fs_fid *newdirfid;
 757         struct v9fs_wstat wstat;
 758         struct v9fs_fcall *fcall = NULL;
 759         int fid = -1;
 760         int olddirfidnum = -1;
 761         int newdirfidnum = -1;
 762         int retval = 0;
 763
 764         dprintk(DEBUG_VFS, "\n");
 765
 766         if(IS_ERR(oldfid))
 767                 return PTR_ERR(oldfid);
 768
 769         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 770         if(IS_ERR(olddirfid)) {
 771                 retval = PTR_ERR(olddirfid);
 772                 goto Release_lock;
 773         }
 774
 775         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 776         if(IS_ERR(newdirfid)) {
 777                 retval = PTR_ERR(newdirfid);
 778                 goto Clunk_olddir;
 779         }
 780
 781         /* 9P can only handle file rename in the same directory */
 782         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 783                 dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
 784                 retval = -EXDEV;
 785                 goto Clunk_newdir;
 786         }
 787
 788         fid = oldfid->fid;
 789         olddirfidnum = olddirfid->fid;
 790         newdirfidnum = newdirfid->fid;
 791
 792         if (fid < 0) {
 793                 dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
 794                         old_inode->i_ino);
 795                 retval = -EBADF;
 796                 goto Clunk_newdir;
 797         }
 798
 799         v9fs_blank_wstat(&wstat);
 800         wstat.muid = v9ses->name;
 801         wstat.name = (char *) new_dentry->d_name.name;
 802
 803         retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
 804
 805         if (retval < 0)
 806                 PRINT_FCALL_ERROR("wstat error", fcall);
 807
 808         kfree(fcall);
 809
 810 Clunk_newdir:
 811         v9fs_fid_clunk(v9ses, newdirfid);
 812
 813 Clunk_olddir:
 814         v9fs_fid_clunk(v9ses, olddirfid);
 815
 816 Release_lock:
 817         up(&oldfid->lock);
 818
 819         return retval;
 820 }
 821
 822 /**
 823  * v9fs_vfs_getattr - retrieve file metadata
 824  * @mnt - mount information
 825  * @dentry - file to get attributes on
 826  * @stat - metadata structure to populate
 827  *
 828  */
 829
 830 static int
 831 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 832                  struct kstat *stat)
 833 {
 834         struct v9fs_fcall *fcall = NULL;
 835         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 836         struct v9fs_fid *fid = v9fs_fid_clone(dentry);
 837         int err = -EPERM;
 838
 839         dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
 840         if(IS_ERR(fid))
 841                 return PTR_ERR(fid);
 842
 843         err = v9fs_t_stat(v9ses, fid->fid, &fcall);
 844
 845         if (err < 0)
 846                 dprintk(DEBUG_ERROR, "stat error\n");
 847         else {
 848                 v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
 849                                   dentry->d_inode->i_sb);
 850                 generic_fillattr(dentry->d_inode, stat);
 851         }
 852
 853         kfree(fcall);
 854         v9fs_fid_clunk(v9ses, fid);
 855         return err;
 856 }
 857
 858 /**
 859  * v9fs_vfs_setattr - set file metadata
 860  * @dentry: file whose metadata to set
 861  * @iattr: metadata assignment structure
 862  *
 863  */
 864
 865 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 866 {
 867         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 868         struct v9fs_fid *fid = v9fs_fid_clone(dentry);
 869         struct v9fs_fcall *fcall = NULL;
 870         struct v9fs_wstat wstat;
 871         int res = -EPERM;
 872
 873         dprintk(DEBUG_VFS, "\n");
 874         if(IS_ERR(fid))
 875                 return PTR_ERR(fid);
 876
 877         v9fs_blank_wstat(&wstat);
 878         if (iattr->ia_valid & ATTR_MODE)
 879                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 880
 881         if (iattr->ia_valid & ATTR_MTIME)
 882                 wstat.mtime = iattr->ia_mtime.tv_sec;
 883
 884         if (iattr->ia_valid & ATTR_ATIME)
 885                 wstat.atime = iattr->ia_atime.tv_sec;
 886
 887         if (iattr->ia_valid & ATTR_SIZE)
 888                 wstat.length = iattr->ia_size;
 889
 890         if (v9ses->extended) {
 891                 if (iattr->ia_valid & ATTR_UID)
 892                         wstat.n_uid = iattr->ia_uid;
 893
 894                 if (iattr->ia_valid & ATTR_GID)
 895                         wstat.n_gid = iattr->ia_gid;
 896         }
 897
 898         res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
 899
 900         if (res < 0)
 901                 PRINT_FCALL_ERROR("wstat error", fcall);
 902
 903         kfree(fcall);
 904         if (res >= 0)
 905                 res = inode_setattr(dentry->d_inode, iattr);
 906
 907         v9fs_fid_clunk(v9ses, fid);
 908         return res;
 909 }
 910
 911 /**
 912  * v9fs_stat2inode - populate an inode structure with mistat info
 913  * @stat: Plan 9 metadata (mistat) structure
 914  * @inode: inode to populate
 915  * @sb: superblock of filesystem
 916  *
 917  */
 918
 919 void
 920 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
 921         struct super_block *sb)
 922 {
 923         int n;
 924         char ext[32];
 925         struct v9fs_session_info *v9ses = sb->s_fs_info;
 926
 927         inode->i_nlink = 1;
 928
 929         inode->i_atime.tv_sec = stat->atime;
 930         inode->i_mtime.tv_sec = stat->mtime;
 931         inode->i_ctime.tv_sec = stat->mtime;
 932
 933         inode->i_uid = v9ses->uid;
 934         inode->i_gid = v9ses->gid;
 935
 936         if (v9ses->extended) {
 937                 inode->i_uid = stat->n_uid;
 938                 inode->i_gid = stat->n_gid;
 939         }
 940
 941         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 942         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 943                 char type = 0;
 944                 int major = -1;
 945                 int minor = -1;
 946
 947                 n = stat->extension.len;
 948                 if (n > sizeof(ext)-1)
 949                         n = sizeof(ext)-1;
 950                 memmove(ext, stat->extension.str, n);
 951                 ext[n] = 0;
 952                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 953                 switch (type) {
 954                 case 'c':
 955                         inode->i_mode &= ~S_IFBLK;
 956                         inode->i_mode |= S_IFCHR;
 957                         break;
 958                 case 'b':
 959                         break;
 960                 default:
 961                         dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
 962                                 type, stat->extension.len, stat->extension.str);
 963                 };
 964                 inode->i_rdev = MKDEV(major, minor);
 965         } else
 966                 inode->i_rdev = 0;
 967
 968         inode->i_size = stat->length;
 969
 970         inode->i_blocks =
 971             (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
 972 }
 973
 974 /**
 975  * v9fs_qid2ino - convert qid into inode number
 976  * @qid: qid to hash
 977  *
 978  * BUG: potential for inode number collisions?
 979  */
 980
 981 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
 982 {
 983         u64 path = qid->path + 2;
 984         ino_t i = 0;
 985
 986         if (sizeof(ino_t) == sizeof(path))
 987                 memcpy(&i, &path, sizeof(ino_t));
 988         else
 989                 i = (ino_t) (path ^ (path >> 32));
 990
 991         return i;
 992 }
 993
 994 /**
 995  * v9fs_readlink - read a symlink's location (internal version)
 996  * @dentry: dentry for symlink
 997  * @buffer: buffer to load symlink location into
 998  * @buflen: length of buffer
 999  *
1000  */
1001
1002 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1003 {
1004         int retval = -EPERM;
1005
1006         struct v9fs_fcall *fcall = NULL;
1007         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
1008         struct v9fs_fid *fid = v9fs_fid_clone(dentry);
1009
1010         if(IS_ERR(fid))
1011                 return PTR_ERR(fid);
1012
1013         if (!v9ses->extended) {
1014                 retval = -EBADF;
1015                 dprintk(DEBUG_ERROR, "not extended\n");
1016                 goto ClunkFid;
1017         }
1018
1019         dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
1020         retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
1021
1022         if (retval < 0) {
1023                 dprintk(DEBUG_ERROR, "stat error\n");
1024                 goto FreeFcall;
1025         }
1026
1027         if (!fcall) {
1028                 retval = -EIO;
1029                 goto ClunkFid;
1030         }
1031
1032         if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1033                 retval = -EINVAL;
1034                 goto FreeFcall;
1035         }
1036
1037         /* copy extension buffer into buffer */
1038         if (fcall->params.rstat.stat.extension.len < buflen)
1039                 buflen = fcall->params.rstat.stat.extension.len + 1;
1040
1041         memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1042         buffer[buflen-1] = 0;
1043
1044         dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1045                 fcall->params.rstat.stat.extension.str, buffer);
1046         retval = buflen;
1047
1048 FreeFcall:
1049         kfree(fcall);
1050
1051 ClunkFid:
1052         v9fs_fid_clunk(v9ses, fid);
1053
1054         return retval;
1055 }
1056
1057 /**
1058  * v9fs_vfs_readlink - read a symlink's location
1059  * @dentry: dentry for symlink
1060  * @buf: buffer to load symlink location into
1061  * @buflen: length of buffer
1062  *
1063  */
1064
1065 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1066                              int buflen)
1067 {
1068         int retval;
1069         int ret;
1070         char *link = __getname();
1071
1072         if (unlikely(!link))
1073                 return -ENOMEM;
1074
1075         if (buflen > PATH_MAX)
1076                 buflen = PATH_MAX;
1077
1078         dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1079
1080         retval = v9fs_readlink(dentry, link, buflen);
1081
1082         if (retval > 0) {
1083                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1084                         dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1085                                 ret);
1086                         retval = ret;
1087                 }
1088         }
1089
1090         __putname(link);
1091         return retval;
1092 }
1093
1094 /**
1095  * v9fs_vfs_follow_link - follow a symlink path
1096  * @dentry: dentry for symlink
1097  * @nd: nameidata
1098  *
1099  */
1100
1101 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1102 {
1103         int len = 0;
1104         char *link = __getname();
1105
1106         dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1107
1108         if (!link)
1109                 link = ERR_PTR(-ENOMEM);
1110         else {
1111                 len = v9fs_readlink(dentry, link, PATH_MAX);
1112
1113                 if (len < 0) {
1114                         __putname(link);
1115                         link = ERR_PTR(len);
1116                 } else
1117                         link[len] = 0;
1118         }
1119         nd_set_link(nd, link);
1120
1121         return NULL;
1122 }
1123
1124 /**
1125  * v9fs_vfs_put_link - release a symlink path
1126  * @dentry: dentry for symlink
1127  * @nd: nameidata
1128  *
1129  */
1130
1131 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1132 {
1133         char *s = nd_get_link(nd);
1134
1135         dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1136         if (!IS_ERR(s))
1137                 __putname(s);
1138 }
1139
1140 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1141         int mode, const char *extension)
1142 {
1143         int err;
1144         u32 fid, perm;
1145         struct v9fs_session_info *v9ses;
1146         struct v9fs_fid *dfid, *vfid = NULL;
1147         struct inode *inode = NULL;
1148
1149         v9ses = v9fs_inode2v9ses(dir);
1150         if (!v9ses->extended) {
1151                 dprintk(DEBUG_ERROR, "not extended\n");
1152                 return -EPERM;
1153         }
1154
1155         dfid = v9fs_fid_clone(dentry->d_parent);
1156         if(IS_ERR(dfid)) {
1157                 err = PTR_ERR(dfid);
1158                 goto error;
1159         }
1160
1161         perm = unixmode2p9mode(v9ses, mode);
1162
1163         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1164                 perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1165
1166         if (err)
1167                 goto clunk_dfid;
1168
1169         err = v9fs_t_clunk(v9ses, fid);
1170         if (err)
1171                 goto clunk_dfid;
1172
1173         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1174         if (IS_ERR(vfid)) {
1175                 err = PTR_ERR(vfid);
1176                 vfid = NULL;
1177                 goto clunk_dfid;
1178         }
1179
1180         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1181         if (IS_ERR(inode)) {
1182                 err = PTR_ERR(inode);
1183                 inode = NULL;
1184                 goto free_vfid;
1185         }
1186
1187         dentry->d_op = &v9fs_dentry_operations;
1188         d_instantiate(dentry, inode);
1189         return 0;
1190
1191 free_vfid:
1192         v9fs_fid_destroy(vfid);
1193
1194 clunk_dfid:
1195         v9fs_fid_clunk(v9ses, dfid);
1196
1197 error:
1198         return err;
1199
1200 }
1201
1202 /**
1203  * v9fs_vfs_symlink - helper function to create symlinks
1204  * @dir: directory inode containing symlink
1205  * @dentry: dentry for symlink
1206  * @symname: symlink data
1207  *
1208  * See 9P2000.u RFC for more information
1209  *
1210  */
1211
1212 static int
1213 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1214 {
1215         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1216                 symname);
1217
1218         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1219 }
1220
1221 /**
1222  * v9fs_vfs_link - create a hardlink
1223  * @old_dentry: dentry for file to link to
1224  * @dir: inode destination for new link
1225  * @dentry: dentry for link
1226  *
1227  */
1228
1229 /* XXX - lots of code dup'd from symlink and creates,
1230  * figure out a better reuse strategy
1231  */
1232
1233 static int
1234 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1235               struct dentry *dentry)
1236 {
1237         int retval;
1238         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1239         struct v9fs_fid *oldfid;
1240         char *name;
1241
1242         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1243                 old_dentry->d_name.name);
1244
1245         oldfid = v9fs_fid_clone(old_dentry);
1246         if(IS_ERR(oldfid))
1247                 return PTR_ERR(oldfid);
1248
1249         name = __getname();
1250         if (unlikely(!name)) {
1251                 retval = -ENOMEM;
1252                 goto clunk_fid;
1253         }
1254
1255         sprintf(name, "%d\n", oldfid->fid);
1256         retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1257         __putname(name);
1258
1259 clunk_fid:
1260         v9fs_fid_clunk(v9ses, oldfid);
1261         return retval;
1262 }
1263
1264 /**
1265  * v9fs_vfs_mknod - create a special file
1266  * @dir: inode destination for new link
1267  * @dentry: dentry for file
1268  * @mode: mode for creation
1269  * @dev_t: device associated with special file
1270  *
1271  */
1272
1273 static int
1274 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1275 {
1276         int retval;
1277         char *name;
1278
1279         dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1280                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1281
1282         if (!new_valid_dev(rdev))
1283                 return -EINVAL;
1284
1285         name = __getname();
1286         if (!name)
1287                 return -ENOMEM;
1288         /* build extension */
1289         if (S_ISBLK(mode))
1290                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1291         else if (S_ISCHR(mode))
1292                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1293         else if (S_ISFIFO(mode))
1294                 *name = 0;
1295         else {
1296                 __putname(name);
1297                 return -EINVAL;
1298         }
1299
1300         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1301         __putname(name);
1302
1303         return retval;
1304 }
1305
1306 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1307         .create = v9fs_vfs_create,
1308         .lookup = v9fs_vfs_lookup,
1309         .symlink = v9fs_vfs_symlink,
1310         .link = v9fs_vfs_link,
1311         .unlink = v9fs_vfs_unlink,
1312         .mkdir = v9fs_vfs_mkdir,
1313         .rmdir = v9fs_vfs_rmdir,
1314         .mknod = v9fs_vfs_mknod,
1315         .rename = v9fs_vfs_rename,
1316         .readlink = v9fs_vfs_readlink,
1317         .getattr = v9fs_vfs_getattr,
1318         .setattr = v9fs_vfs_setattr,
1319 };
1320
1321 static const struct inode_operations v9fs_dir_inode_operations = {
1322         .create = v9fs_vfs_create,
1323         .lookup = v9fs_vfs_lookup,
1324         .unlink = v9fs_vfs_unlink,
1325         .mkdir = v9fs_vfs_mkdir,
1326         .rmdir = v9fs_vfs_rmdir,
1327         .mknod = v9fs_vfs_mknod,
1328         .rename = v9fs_vfs_rename,
1329         .getattr = v9fs_vfs_getattr,
1330         .setattr = v9fs_vfs_setattr,
1331 };
1332
1333 static const struct inode_operations v9fs_file_inode_operations = {
1334         .getattr = v9fs_vfs_getattr,
1335         .setattr = v9fs_vfs_setattr,
1336 };
1337
1338 static const struct inode_operations v9fs_symlink_inode_operations = {
1339         .readlink = v9fs_vfs_readlink,
1340         .follow_link = v9fs_vfs_follow_link,
1341         .put_link = v9fs_vfs_put_link,
1342         .getattr = v9fs_vfs_getattr,
1343         .setattr = v9fs_vfs_setattr,
1344 };