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   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_clone(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         if(v9ses->cache)
 508                 dentry->d_op = &v9fs_cached_dentry_operations;
 509         else
 510                 dentry->d_op = &v9fs_dentry_operations;
 511         d_instantiate(dentry, inode);
 512
 513         if (nd && nd->flags & LOOKUP_OPEN) {
 514                 ffid = v9fs_fid_create(v9ses, fid);
 515                 if (!ffid)
 516                         return -ENOMEM;
 517
 518                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 519                 if (IS_ERR(filp)) {
 520                         v9fs_fid_destroy(ffid);
 521                         return PTR_ERR(filp);
 522                 }
 523
 524                 ffid->rdir_pos = 0;
 525                 ffid->rdir_fcall = NULL;
 526                 ffid->fidopen = 1;
 527                 ffid->iounit = iounit;
 528                 ffid->filp = filp;
 529                 filp->private_data = ffid;
 530         }
 531
 532         return 0;
 533
 534 clunk_dfid:
 535         v9fs_fid_clunk(v9ses, dfid);
 536
 537 error:
 538         if (vfid)
 539                 v9fs_fid_destroy(vfid);
 540
 541         return err;
 542 }
 543
 544 /**
 545  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 546  * @inode:  inode that is being unlinked
 547  * @dentry: dentry that is being unlinked
 548  * @mode: mode for new directory
 549  *
 550  */
 551
 552 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 553 {
 554         int err;
 555         u32 fid, perm;
 556         struct v9fs_session_info *v9ses;
 557         struct v9fs_fid *dfid, *vfid;
 558         struct inode *inode;
 559
 560         inode = NULL;
 561         vfid = NULL;
 562         v9ses = v9fs_inode2v9ses(dir);
 563         dfid = v9fs_fid_clone(dentry->d_parent);
 564         if(IS_ERR(dfid)) {
 565                 err = PTR_ERR(dfid);
 566                 goto error;
 567         }
 568
 569         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 570
 571         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 572                 perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
 573
 574         if (err) {
 575                 dprintk(DEBUG_ERROR, "create error %d\n", err);
 576                 goto clean_up_dfid;
 577         }
 578
 579         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 580         if (IS_ERR(vfid)) {
 581                 err = PTR_ERR(vfid);
 582                 vfid = NULL;
 583                 goto clean_up_dfid;
 584         }
 585
 586         v9fs_fid_clunk(v9ses, dfid);
 587         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 588         if (IS_ERR(inode)) {
 589                 err = PTR_ERR(inode);
 590                 inode = NULL;
 591                 v9fs_fid_destroy(vfid);
 592                 goto error;
 593         }
 594
 595         if(v9ses->cache)
 596                 dentry->d_op = &v9fs_cached_dentry_operations;
 597         else
 598                 dentry->d_op = &v9fs_dentry_operations;
 599         d_instantiate(dentry, inode);
 600         return 0;
 601
 602 clean_up_dfid:
 603         v9fs_fid_clunk(v9ses, dfid);
 604
 605 error:
 606         return err;
 607 }
 608
 609 /**
 610  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 611  * @dir:  inode that is being walked from
 612  * @dentry: dentry that is being walked to?
 613  * @nameidata: path data
 614  *
 615  */
 616
 617 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 618                                       struct nameidata *nameidata)
 619 {
 620         struct super_block *sb;
 621         struct v9fs_session_info *v9ses;
 622         struct v9fs_fid *dirfid;
 623         struct v9fs_fid *fid;
 624         struct inode *inode;
 625         struct v9fs_fcall *fcall = NULL;
 626         int dirfidnum = -1;
 627         int newfid = -1;
 628         int result = 0;
 629
 630         dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 631                 dir, dentry->d_name.name, dentry, nameidata);
 632
 633         sb = dir->i_sb;
 634         v9ses = v9fs_inode2v9ses(dir);
 635         dirfid = v9fs_fid_lookup(dentry->d_parent);
 636
 637         if(IS_ERR(dirfid))
 638                 return ERR_PTR(PTR_ERR(dirfid));
 639
 640         dirfidnum = dirfid->fid;
 641
 642         newfid = v9fs_get_idpool(&v9ses->fidpool);
 643         if (newfid < 0) {
 644                 eprintk(KERN_WARNING, "newfid fails!\n");
 645                 result = -ENOSPC;
 646                 goto Release_Dirfid;
 647         }
 648
 649         result = v9fs_t_walk(v9ses, dirfidnum, newfid,
 650                 (char *)dentry->d_name.name, &fcall);
 651
 652         up(&dirfid->lock);
 653
 654         if (result < 0) {
 655                 if (fcall && fcall->id == RWALK)
 656                         v9fs_t_clunk(v9ses, newfid);
 657                 else
 658                         v9fs_put_idpool(newfid, &v9ses->fidpool);
 659
 660                 if (result == -ENOENT) {
 661                         d_add(dentry, NULL);
 662                         dprintk(DEBUG_VFS,
 663                                 "Return negative dentry %p count %d\n",
 664                                 dentry, atomic_read(&dentry->d_count));
 665                         kfree(fcall);
 666                         return NULL;
 667                 }
 668                 dprintk(DEBUG_ERROR, "walk error:%d\n", result);
 669                 goto FreeFcall;
 670         }
 671         kfree(fcall);
 672
 673         result = v9fs_t_stat(v9ses, newfid, &fcall);
 674         if (result < 0) {
 675                 dprintk(DEBUG_ERROR, "stat error\n");
 676                 goto FreeFcall;
 677         }
 678
 679         inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
 680                 fcall->params.rstat.stat.mode));
 681
 682         if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
 683                 eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
 684                         PTR_ERR(inode));
 685
 686                 result = -ENOSPC;
 687                 goto FreeFcall;
 688         }
 689
 690         inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
 691
 692         fid = v9fs_fid_create(v9ses, newfid);
 693         if (fid == NULL) {
 694                 dprintk(DEBUG_ERROR, "couldn't insert\n");
 695                 result = -ENOMEM;
 696                 goto FreeFcall;
 697         }
 698
 699         result = v9fs_fid_insert(fid, dentry);
 700         if (result < 0)
 701                 goto FreeFcall;
 702
 703         fid->qid = fcall->params.rstat.stat.qid;
 704         v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
 705         if((fid->qid.version)&&(v9ses->cache))
 706                 dentry->d_op = &v9fs_cached_dentry_operations;
 707         else
 708                 dentry->d_op = &v9fs_dentry_operations;
 709
 710         d_add(dentry, inode);
 711         kfree(fcall);
 712
 713         return NULL;
 714
 715 Release_Dirfid:
 716         up(&dirfid->lock);
 717
 718 FreeFcall:
 719         kfree(fcall);
 720
 721         return ERR_PTR(result);
 722 }
 723
 724 /**
 725  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 726  * @i:  inode that is being unlinked
 727  * @d: dentry that is being unlinked
 728  *
 729  */
 730
 731 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 732 {
 733         return v9fs_remove(i, d, 0);
 734 }
 735
 736 /**
 737  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 738  * @i:  inode that is being unlinked
 739  * @d: dentry that is being unlinked
 740  *
 741  */
 742
 743 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 744 {
 745         return v9fs_remove(i, d, 1);
 746 }
 747
 748 /**
 749  * v9fs_vfs_rename - VFS hook to rename an inode
 750  * @old_dir:  old dir inode
 751  * @old_dentry: old dentry
 752  * @new_dir: new dir inode
 753  * @new_dentry: new dentry
 754  *
 755  */
 756
 757 static int
 758 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 759                 struct inode *new_dir, struct dentry *new_dentry)
 760 {
 761         struct inode *old_inode = old_dentry->d_inode;
 762         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
 763         struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
 764         struct v9fs_fid *olddirfid;
 765         struct v9fs_fid *newdirfid;
 766         struct v9fs_wstat wstat;
 767         struct v9fs_fcall *fcall = NULL;
 768         int fid = -1;
 769         int olddirfidnum = -1;
 770         int newdirfidnum = -1;
 771         int retval = 0;
 772
 773         dprintk(DEBUG_VFS, "\n");
 774
 775         if(IS_ERR(oldfid))
 776                 return PTR_ERR(oldfid);
 777
 778         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 779         if(IS_ERR(olddirfid)) {
 780                 retval = PTR_ERR(olddirfid);
 781                 goto Release_lock;
 782         }
 783
 784         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 785         if(IS_ERR(newdirfid)) {
 786                 retval = PTR_ERR(newdirfid);
 787                 goto Clunk_olddir;
 788         }
 789
 790         /* 9P can only handle file rename in the same directory */
 791         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 792                 dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
 793                 retval = -EXDEV;
 794                 goto Clunk_newdir;
 795         }
 796
 797         fid = oldfid->fid;
 798         olddirfidnum = olddirfid->fid;
 799         newdirfidnum = newdirfid->fid;
 800
 801         if (fid < 0) {
 802                 dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
 803                         old_inode->i_ino);
 804                 retval = -EBADF;
 805                 goto Clunk_newdir;
 806         }
 807
 808         v9fs_blank_wstat(&wstat);
 809         wstat.muid = v9ses->name;
 810         wstat.name = (char *) new_dentry->d_name.name;
 811
 812         retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
 813
 814         if (retval < 0)
 815                 PRINT_FCALL_ERROR("wstat error", fcall);
 816
 817         kfree(fcall);
 818
 819 Clunk_newdir:
 820         v9fs_fid_clunk(v9ses, newdirfid);
 821
 822 Clunk_olddir:
 823         v9fs_fid_clunk(v9ses, olddirfid);
 824
 825 Release_lock:
 826         up(&oldfid->lock);
 827
 828         return retval;
 829 }
 830
 831 /**
 832  * v9fs_vfs_getattr - retrieve file metadata
 833  * @mnt - mount information
 834  * @dentry - file to get attributes on
 835  * @stat - metadata structure to populate
 836  *
 837  */
 838
 839 static int
 840 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 841                  struct kstat *stat)
 842 {
 843         struct v9fs_fcall *fcall = NULL;
 844         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 845         struct v9fs_fid *fid = v9fs_fid_clone(dentry);
 846         int err = -EPERM;
 847
 848         dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
 849         if(IS_ERR(fid))
 850                 return PTR_ERR(fid);
 851
 852         err = v9fs_t_stat(v9ses, fid->fid, &fcall);
 853
 854         if (err < 0)
 855                 dprintk(DEBUG_ERROR, "stat error\n");
 856         else {
 857                 v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
 858                                   dentry->d_inode->i_sb);
 859                 generic_fillattr(dentry->d_inode, stat);
 860         }
 861
 862         kfree(fcall);
 863         v9fs_fid_clunk(v9ses, fid);
 864         return err;
 865 }
 866
 867 /**
 868  * v9fs_vfs_setattr - set file metadata
 869  * @dentry: file whose metadata to set
 870  * @iattr: metadata assignment structure
 871  *
 872  */
 873
 874 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 875 {
 876         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 877         struct v9fs_fid *fid = v9fs_fid_clone(dentry);
 878         struct v9fs_fcall *fcall = NULL;
 879         struct v9fs_wstat wstat;
 880         int res = -EPERM;
 881
 882         dprintk(DEBUG_VFS, "\n");
 883         if(IS_ERR(fid))
 884                 return PTR_ERR(fid);
 885
 886         v9fs_blank_wstat(&wstat);
 887         if (iattr->ia_valid & ATTR_MODE)
 888                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 889
 890         if (iattr->ia_valid & ATTR_MTIME)
 891                 wstat.mtime = iattr->ia_mtime.tv_sec;
 892
 893         if (iattr->ia_valid & ATTR_ATIME)
 894                 wstat.atime = iattr->ia_atime.tv_sec;
 895
 896         if (iattr->ia_valid & ATTR_SIZE)
 897                 wstat.length = iattr->ia_size;
 898
 899         if (v9ses->extended) {
 900                 if (iattr->ia_valid & ATTR_UID)
 901                         wstat.n_uid = iattr->ia_uid;
 902
 903                 if (iattr->ia_valid & ATTR_GID)
 904                         wstat.n_gid = iattr->ia_gid;
 905         }
 906
 907         res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
 908
 909         if (res < 0)
 910                 PRINT_FCALL_ERROR("wstat error", fcall);
 911
 912         kfree(fcall);
 913         if (res >= 0)
 914                 res = inode_setattr(dentry->d_inode, iattr);
 915
 916         v9fs_fid_clunk(v9ses, fid);
 917         return res;
 918 }
 919
 920 /**
 921  * v9fs_stat2inode - populate an inode structure with mistat info
 922  * @stat: Plan 9 metadata (mistat) structure
 923  * @inode: inode to populate
 924  * @sb: superblock of filesystem
 925  *
 926  */
 927
 928 void
 929 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
 930         struct super_block *sb)
 931 {
 932         int n;
 933         char ext[32];
 934         struct v9fs_session_info *v9ses = sb->s_fs_info;
 935
 936         inode->i_nlink = 1;
 937
 938         inode->i_atime.tv_sec = stat->atime;
 939         inode->i_mtime.tv_sec = stat->mtime;
 940         inode->i_ctime.tv_sec = stat->mtime;
 941
 942         inode->i_uid = v9ses->uid;
 943         inode->i_gid = v9ses->gid;
 944
 945         if (v9ses->extended) {
 946                 inode->i_uid = stat->n_uid;
 947                 inode->i_gid = stat->n_gid;
 948         }
 949
 950         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 951         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 952                 char type = 0;
 953                 int major = -1;
 954                 int minor = -1;
 955
 956                 n = stat->extension.len;
 957                 if (n > sizeof(ext)-1)
 958                         n = sizeof(ext)-1;
 959                 memmove(ext, stat->extension.str, n);
 960                 ext[n] = 0;
 961                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 962                 switch (type) {
 963                 case 'c':
 964                         inode->i_mode &= ~S_IFBLK;
 965                         inode->i_mode |= S_IFCHR;
 966                         break;
 967                 case 'b':
 968                         break;
 969                 default:
 970                         dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
 971                                 type, stat->extension.len, stat->extension.str);
 972                 };
 973                 inode->i_rdev = MKDEV(major, minor);
 974         } else
 975                 inode->i_rdev = 0;
 976
 977         inode->i_size = stat->length;
 978
 979         inode->i_blocks =
 980             (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
 981 }
 982
 983 /**
 984  * v9fs_qid2ino - convert qid into inode number
 985  * @qid: qid to hash
 986  *
 987  * BUG: potential for inode number collisions?
 988  */
 989
 990 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
 991 {
 992         u64 path = qid->path + 2;
 993         ino_t i = 0;
 994
 995         if (sizeof(ino_t) == sizeof(path))
 996                 memcpy(&i, &path, sizeof(ino_t));
 997         else
 998                 i = (ino_t) (path ^ (path >> 32));
 999
1000         return i;
1001 }
1002
1003 /**
1004  * v9fs_readlink - read a symlink's location (internal version)
1005  * @dentry: dentry for symlink
1006  * @buffer: buffer to load symlink location into
1007  * @buflen: length of buffer
1008  *
1009  */
1010
1011 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
1012 {
1013         int retval = -EPERM;
1014
1015         struct v9fs_fcall *fcall = NULL;
1016         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
1017         struct v9fs_fid *fid = v9fs_fid_clone(dentry);
1018
1019         if(IS_ERR(fid))
1020                 return PTR_ERR(fid);
1021
1022         if (!v9ses->extended) {
1023                 retval = -EBADF;
1024                 dprintk(DEBUG_ERROR, "not extended\n");
1025                 goto ClunkFid;
1026         }
1027
1028         dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
1029         retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
1030
1031         if (retval < 0) {
1032                 dprintk(DEBUG_ERROR, "stat error\n");
1033                 goto FreeFcall;
1034         }
1035
1036         if (!fcall) {
1037                 retval = -EIO;
1038                 goto ClunkFid;
1039         }
1040
1041         if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1042                 retval = -EINVAL;
1043                 goto FreeFcall;
1044         }
1045
1046         /* copy extension buffer into buffer */
1047         if (fcall->params.rstat.stat.extension.len < buflen)
1048                 buflen = fcall->params.rstat.stat.extension.len + 1;
1049
1050         memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1051         buffer[buflen-1] = 0;
1052
1053         dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1054                 fcall->params.rstat.stat.extension.str, buffer);
1055         retval = buflen;
1056
1057 FreeFcall:
1058         kfree(fcall);
1059
1060 ClunkFid:
1061         v9fs_fid_clunk(v9ses, fid);
1062
1063         return retval;
1064 }
1065
1066 /**
1067  * v9fs_vfs_readlink - read a symlink's location
1068  * @dentry: dentry for symlink
1069  * @buf: buffer to load symlink location into
1070  * @buflen: length of buffer
1071  *
1072  */
1073
1074 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1075                              int buflen)
1076 {
1077         int retval;
1078         int ret;
1079         char *link = __getname();
1080
1081         if (unlikely(!link))
1082                 return -ENOMEM;
1083
1084         if (buflen > PATH_MAX)
1085                 buflen = PATH_MAX;
1086
1087         dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1088
1089         retval = v9fs_readlink(dentry, link, buflen);
1090
1091         if (retval > 0) {
1092                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1093                         dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1094                                 ret);
1095                         retval = ret;
1096                 }
1097         }
1098
1099         __putname(link);
1100         return retval;
1101 }
1102
1103 /**
1104  * v9fs_vfs_follow_link - follow a symlink path
1105  * @dentry: dentry for symlink
1106  * @nd: nameidata
1107  *
1108  */
1109
1110 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1111 {
1112         int len = 0;
1113         char *link = __getname();
1114
1115         dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1116
1117         if (!link)
1118                 link = ERR_PTR(-ENOMEM);
1119         else {
1120                 len = v9fs_readlink(dentry, link, PATH_MAX);
1121
1122                 if (len < 0) {
1123                         __putname(link);
1124                         link = ERR_PTR(len);
1125                 } else
1126                         link[len] = 0;
1127         }
1128         nd_set_link(nd, link);
1129
1130         return NULL;
1131 }
1132
1133 /**
1134  * v9fs_vfs_put_link - release a symlink path
1135  * @dentry: dentry for symlink
1136  * @nd: nameidata
1137  *
1138  */
1139
1140 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1141 {
1142         char *s = nd_get_link(nd);
1143
1144         dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1145         if (!IS_ERR(s))
1146                 __putname(s);
1147 }
1148
1149 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1150         int mode, const char *extension)
1151 {
1152         int err;
1153         u32 fid, perm;
1154         struct v9fs_session_info *v9ses;
1155         struct v9fs_fid *dfid, *vfid = NULL;
1156         struct inode *inode = NULL;
1157
1158         v9ses = v9fs_inode2v9ses(dir);
1159         if (!v9ses->extended) {
1160                 dprintk(DEBUG_ERROR, "not extended\n");
1161                 return -EPERM;
1162         }
1163
1164         dfid = v9fs_fid_clone(dentry->d_parent);
1165         if(IS_ERR(dfid)) {
1166                 err = PTR_ERR(dfid);
1167                 goto error;
1168         }
1169
1170         perm = unixmode2p9mode(v9ses, mode);
1171
1172         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1173                 perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1174
1175         if (err)
1176                 goto clunk_dfid;
1177
1178         err = v9fs_t_clunk(v9ses, fid);
1179         if (err)
1180                 goto clunk_dfid;
1181
1182         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1183         if (IS_ERR(vfid)) {
1184                 err = PTR_ERR(vfid);
1185                 vfid = NULL;
1186                 goto clunk_dfid;
1187         }
1188
1189         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1190         if (IS_ERR(inode)) {
1191                 err = PTR_ERR(inode);
1192                 inode = NULL;
1193                 goto free_vfid;
1194         }
1195
1196         if(v9ses->cache)
1197                 dentry->d_op = &v9fs_cached_dentry_operations;
1198         else
1199                 dentry->d_op = &v9fs_dentry_operations;
1200         d_instantiate(dentry, inode);
1201         return 0;
1202
1203 free_vfid:
1204         v9fs_fid_destroy(vfid);
1205
1206 clunk_dfid:
1207         v9fs_fid_clunk(v9ses, dfid);
1208
1209 error:
1210         return err;
1211
1212 }
1213
1214 /**
1215  * v9fs_vfs_symlink - helper function to create symlinks
1216  * @dir: directory inode containing symlink
1217  * @dentry: dentry for symlink
1218  * @symname: symlink data
1219  *
1220  * See 9P2000.u RFC for more information
1221  *
1222  */
1223
1224 static int
1225 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1226 {
1227         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1228                 symname);
1229
1230         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1231 }
1232
1233 /**
1234  * v9fs_vfs_link - create a hardlink
1235  * @old_dentry: dentry for file to link to
1236  * @dir: inode destination for new link
1237  * @dentry: dentry for link
1238  *
1239  */
1240
1241 /* XXX - lots of code dup'd from symlink and creates,
1242  * figure out a better reuse strategy
1243  */
1244
1245 static int
1246 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1247               struct dentry *dentry)
1248 {
1249         int retval;
1250         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
1251         struct v9fs_fid *oldfid;
1252         char *name;
1253
1254         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1255                 old_dentry->d_name.name);
1256
1257         oldfid = v9fs_fid_clone(old_dentry);
1258         if(IS_ERR(oldfid))
1259                 return PTR_ERR(oldfid);
1260
1261         name = __getname();
1262         if (unlikely(!name)) {
1263                 retval = -ENOMEM;
1264                 goto clunk_fid;
1265         }
1266
1267         sprintf(name, "%d\n", oldfid->fid);
1268         retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1269         __putname(name);
1270
1271 clunk_fid:
1272         v9fs_fid_clunk(v9ses, oldfid);
1273         return retval;
1274 }
1275
1276 /**
1277  * v9fs_vfs_mknod - create a special file
1278  * @dir: inode destination for new link
1279  * @dentry: dentry for file
1280  * @mode: mode for creation
1281  * @dev_t: device associated with special file
1282  *
1283  */
1284
1285 static int
1286 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1287 {
1288         int retval;
1289         char *name;
1290
1291         dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1292                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1293
1294         if (!new_valid_dev(rdev))
1295                 return -EINVAL;
1296
1297         name = __getname();
1298         if (!name)
1299                 return -ENOMEM;
1300         /* build extension */
1301         if (S_ISBLK(mode))
1302                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1303         else if (S_ISCHR(mode))
1304                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1305         else if (S_ISFIFO(mode))
1306                 *name = 0;
1307         else {
1308                 __putname(name);
1309                 return -EINVAL;
1310         }
1311
1312         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1313         __putname(name);
1314
1315         return retval;
1316 }
1317
1318 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1319         .create = v9fs_vfs_create,
1320         .lookup = v9fs_vfs_lookup,
1321         .symlink = v9fs_vfs_symlink,
1322         .link = v9fs_vfs_link,
1323         .unlink = v9fs_vfs_unlink,
1324         .mkdir = v9fs_vfs_mkdir,
1325         .rmdir = v9fs_vfs_rmdir,
1326         .mknod = v9fs_vfs_mknod,
1327         .rename = v9fs_vfs_rename,
1328         .readlink = v9fs_vfs_readlink,
1329         .getattr = v9fs_vfs_getattr,
1330         .setattr = v9fs_vfs_setattr,
1331 };
1332
1333 static const struct inode_operations v9fs_dir_inode_operations = {
1334         .create = v9fs_vfs_create,
1335         .lookup = v9fs_vfs_lookup,
1336         .unlink = v9fs_vfs_unlink,
1337         .mkdir = v9fs_vfs_mkdir,
1338         .rmdir = v9fs_vfs_rmdir,
1339         .mknod = v9fs_vfs_mknod,
1340         .rename = v9fs_vfs_rename,
1341         .getattr = v9fs_vfs_getattr,
1342         .setattr = v9fs_vfs_setattr,
1343 };
1344
1345 static const struct inode_operations v9fs_file_inode_operations = {
1346         .getattr = v9fs_vfs_getattr,
1347         .setattr = v9fs_vfs_setattr,
1348 };
1349
1350 static const struct inode_operations v9fs_symlink_inode_operations = {
1351         .readlink = v9fs_vfs_readlink,
1352         .follow_link = v9fs_vfs_follow_link,
1353         .put_link = v9fs_vfs_put_link,
1354         .getattr = v9fs_vfs_getattr,
1355         .setattr = v9fs_vfs_setattr,
1356 };