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