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         u32 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         u32 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
 420         if (!v9fid) {
 421                 dprintk(DEBUG_ERROR,
 422                         "no v9fs_fid\n");
 423                 return -EBADF;
 424         }
 425
 426         fid = v9fid->fid;
 427         if (fid < 0) {
 428                 dprintk(DEBUG_ERROR, "inode #%lu, no fid!\n",
 429                         file_inode->i_ino);
 430                 return -EBADF;
 431         }
 432
 433         result = v9fs_t_remove(v9ses, fid, &fcall);
 434         if (result < 0) {
 435                 PRINT_FCALL_ERROR("remove fails", fcall);
 436         }
 437
 438         v9fs_put_idpool(fid, &v9ses->fidpool);
 439         v9fs_fid_destroy(v9fid);
 440
 441         kfree(fcall);
 442         return result;
 443 }
 444
 445 static int
 446 v9fs_open_created(struct inode *inode, struct file *file)
 447 {
 448         return 0;
 449 }
 450
 451 /**
 452  * v9fs_vfs_create - VFS hook to create files
 453  * @inode: directory inode that is being deleted
 454  * @dentry:  dentry that is being deleted
 455  * @mode: create permissions
 456  * @nd: path information
 457  *
 458  */
 459
 460 static int
 461 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 462                 struct nameidata *nd)
 463 {
 464         int err;
 465         u32 fid, perm, iounit;
 466         int flags;
 467         struct v9fs_session_info *v9ses;
 468         struct v9fs_fid *dfid, *vfid, *ffid;
 469         struct inode *inode;
 470         struct v9fs_qid qid;
 471         struct file *filp;
 472
 473         inode = NULL;
 474         vfid = NULL;
 475         v9ses = v9fs_inode2v9ses(dir);
 476         dfid = v9fs_fid_lookup(dentry->d_parent);
 477         perm = unixmode2p9mode(v9ses, mode);
 478
 479         if (nd && nd->flags & LOOKUP_OPEN)
 480                 flags = nd->intent.open.flags - 1;
 481         else
 482                 flags = O_RDWR;
 483
 484         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 485                 perm, v9fs_uflags2omode(flags), NULL, &fid, &qid, &iounit);
 486
 487         if (err)
 488                 goto error;
 489
 490         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 491         if (IS_ERR(vfid)) {
 492                 err = PTR_ERR(vfid);
 493                 vfid = NULL;
 494                 goto error;
 495         }
 496
 497         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 498         if (IS_ERR(inode)) {
 499                 err = PTR_ERR(inode);
 500                 inode = NULL;
 501                 goto error;
 502         }
 503
 504         dentry->d_op = &v9fs_dentry_operations;
 505         d_instantiate(dentry, inode);
 506
 507         if (nd && nd->flags & LOOKUP_OPEN) {
 508                 ffid = v9fs_fid_create(v9ses, fid);
 509                 if (!ffid)
 510                         return -ENOMEM;
 511
 512                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 513                 if (IS_ERR(filp)) {
 514                         v9fs_fid_destroy(ffid);
 515                         return PTR_ERR(filp);
 516                 }
 517
 518                 ffid->rdir_pos = 0;
 519                 ffid->rdir_fcall = NULL;
 520                 ffid->fidopen = 1;
 521                 ffid->iounit = iounit;
 522                 ffid->filp = filp;
 523                 filp->private_data = ffid;
 524         }
 525
 526         return 0;
 527
 528 error:
 529         if (vfid)
 530                 v9fs_fid_destroy(vfid);
 531
 532         return err;
 533 }
 534
 535 /**
 536  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 537  * @inode:  inode that is being unlinked
 538  * @dentry: dentry that is being unlinked
 539  * @mode: mode for new directory
 540  *
 541  */
 542
 543 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 544 {
 545         int err;
 546         u32 fid, perm;
 547         struct v9fs_session_info *v9ses;
 548         struct v9fs_fid *dfid, *vfid;
 549         struct inode *inode;
 550
 551         inode = NULL;
 552         vfid = NULL;
 553         v9ses = v9fs_inode2v9ses(dir);
 554         dfid = v9fs_fid_lookup(dentry->d_parent);
 555         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 556
 557         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 558                 perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
 559
 560         if (err) {
 561                 dprintk(DEBUG_ERROR, "create error %d\n", err);
 562                 goto error;
 563         }
 564
 565         err = v9fs_t_clunk(v9ses, fid);
 566         if (err) {
 567                 dprintk(DEBUG_ERROR, "clunk error %d\n", err);
 568                 goto error;
 569         }
 570
 571         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 572         if (IS_ERR(vfid)) {
 573                 err = PTR_ERR(vfid);
 574                 vfid = NULL;
 575                 goto error;
 576         }
 577
 578         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 579         if (IS_ERR(inode)) {
 580                 err = PTR_ERR(inode);
 581                 inode = NULL;
 582                 goto error;
 583         }
 584
 585         dentry->d_op = &v9fs_dentry_operations;
 586         d_instantiate(dentry, inode);
 587         return 0;
 588
 589 error:
 590         if (vfid)
 591                 v9fs_fid_destroy(vfid);
 592
 593         return err;
 594 }
 595
 596 /**
 597  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 598  * @dir:  inode that is being walked from
 599  * @dentry: dentry that is being walked to?
 600  * @nameidata: path data
 601  *
 602  */
 603
 604 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 605                                       struct nameidata *nameidata)
 606 {
 607         struct super_block *sb;
 608         struct v9fs_session_info *v9ses;
 609         struct v9fs_fid *dirfid;
 610         struct v9fs_fid *fid;
 611         struct inode *inode;
 612         struct v9fs_fcall *fcall = NULL;
 613         int dirfidnum = -1;
 614         int newfid = -1;
 615         int result = 0;
 616
 617         dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 618                 dir, dentry->d_name.name, dentry, nameidata);
 619
 620         sb = dir->i_sb;
 621         v9ses = v9fs_inode2v9ses(dir);
 622         dentry->d_op = &v9fs_dentry_operations;
 623         dirfid = v9fs_fid_lookup(dentry->d_parent);
 624
 625         if (!dirfid) {
 626                 dprintk(DEBUG_ERROR, "no dirfid\n");
 627                 return ERR_PTR(-EINVAL);
 628         }
 629
 630         dirfidnum = dirfid->fid;
 631
 632         if (dirfidnum < 0) {
 633                 dprintk(DEBUG_ERROR, "no dirfid for inode %p, #%lu\n",
 634                         dir, dir->i_ino);
 635                 return ERR_PTR(-EBADF);
 636         }
 637
 638         newfid = v9fs_get_idpool(&v9ses->fidpool);
 639         if (newfid < 0) {
 640                 eprintk(KERN_WARNING, "newfid fails!\n");
 641                 return ERR_PTR(-ENOSPC);
 642         }
 643
 644         result = v9fs_t_walk(v9ses, dirfidnum, newfid,
 645                 (char *)dentry->d_name.name, &fcall);
 646
 647         if (result < 0) {
 648                 if (fcall && fcall->id == RWALK)
 649                         v9fs_t_clunk(v9ses, newfid);
 650                 else
 651                         v9fs_put_idpool(newfid, &v9ses->fidpool);
 652
 653                 if (result == -ENOENT) {
 654                         d_add(dentry, NULL);
 655                         dprintk(DEBUG_VFS,
 656                                 "Return negative dentry %p count %d\n",
 657                                 dentry, atomic_read(&dentry->d_count));
 658                         kfree(fcall);
 659                         return NULL;
 660                 }
 661                 dprintk(DEBUG_ERROR, "walk error:%d\n", result);
 662                 goto FreeFcall;
 663         }
 664         kfree(fcall);
 665
 666         result = v9fs_t_stat(v9ses, newfid, &fcall);
 667         if (result < 0) {
 668                 dprintk(DEBUG_ERROR, "stat error\n");
 669                 goto FreeFcall;
 670         }
 671
 672         inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
 673                 fcall->params.rstat.stat.mode));
 674
 675         if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
 676                 eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
 677                         PTR_ERR(inode));
 678
 679                 result = -ENOSPC;
 680                 goto FreeFcall;
 681         }
 682
 683         inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
 684
 685         fid = v9fs_fid_create(v9ses, newfid);
 686         if (fid == NULL) {
 687                 dprintk(DEBUG_ERROR, "couldn't insert\n");
 688                 result = -ENOMEM;
 689                 goto FreeFcall;
 690         }
 691
 692         result = v9fs_fid_insert(fid, dentry);
 693         if (result < 0)
 694                 goto FreeFcall;
 695
 696         fid->qid = fcall->params.rstat.stat.qid;
 697         v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
 698
 699         d_add(dentry, inode);
 700         kfree(fcall);
 701
 702         return NULL;
 703
 704       FreeFcall:
 705         kfree(fcall);
 706         return ERR_PTR(result);
 707 }
 708
 709 /**
 710  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 711  * @i:  inode that is being unlinked
 712  * @d: dentry that is being unlinked
 713  *
 714  */
 715
 716 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 717 {
 718         return v9fs_remove(i, d, 0);
 719 }
 720
 721 /**
 722  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 723  * @i:  inode that is being unlinked
 724  * @d: dentry that is being unlinked
 725  *
 726  */
 727
 728 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 729 {
 730         return v9fs_remove(i, d, 1);
 731 }
 732
 733 /**
 734  * v9fs_vfs_rename - VFS hook to rename an inode
 735  * @old_dir:  old dir inode
 736  * @old_dentry: old dentry
 737  * @new_dir: new dir inode
 738  * @new_dentry: new dentry
 739  *
 740  */
 741
 742 static int
 743 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 744                 struct inode *new_dir, struct dentry *new_dentry)
 745 {
 746         struct inode *old_inode = old_dentry->d_inode;
 747         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
 748         struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
 749         struct v9fs_fid *olddirfid =
 750             v9fs_fid_lookup(old_dentry->d_parent);
 751         struct v9fs_fid *newdirfid =
 752             v9fs_fid_lookup(new_dentry->d_parent);
 753         struct v9fs_wstat wstat;
 754         struct v9fs_fcall *fcall = NULL;
 755         int fid = -1;
 756         int olddirfidnum = -1;
 757         int newdirfidnum = -1;
 758         int retval = 0;
 759
 760         dprintk(DEBUG_VFS, "\n");
 761
 762         if ((!oldfid) || (!olddirfid) || (!newdirfid)) {
 763                 dprintk(DEBUG_ERROR, "problem with arguments\n");
 764                 return -EBADF;
 765         }
 766
 767         /* 9P can only handle file rename in the same directory */
 768         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 769                 dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
 770                 retval = -EPERM;
 771                 goto FreeFcallnBail;
 772         }
 773
 774         fid = oldfid->fid;
 775         olddirfidnum = olddirfid->fid;
 776         newdirfidnum = newdirfid->fid;
 777
 778         if (fid < 0) {
 779                 dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
 780                         old_inode->i_ino);
 781                 retval = -EBADF;
 782                 goto FreeFcallnBail;
 783         }
 784
 785         v9fs_blank_wstat(&wstat);
 786         wstat.muid = v9ses->name;
 787         wstat.name = (char *) new_dentry->d_name.name;
 788
 789         retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
 790
 791       FreeFcallnBail:
 792         if (retval < 0)
 793                 PRINT_FCALL_ERROR("wstat error", fcall);
 794
 795         kfree(fcall);
 796         return retval;
 797 }
 798
 799 /**
 800  * v9fs_vfs_getattr - retrieve file metadata
 801  * @mnt - mount information
 802  * @dentry - file to get attributes on
 803  * @stat - metadata structure to populate
 804  *
 805  */
 806
 807 static int
 808 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 809                  struct kstat *stat)
 810 {
 811         struct v9fs_fcall *fcall = NULL;
 812         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 813         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 814         int err = -EPERM;
 815
 816         dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
 817         if (!fid) {
 818                 dprintk(DEBUG_ERROR,
 819                         "couldn't find fid associated with dentry\n");
 820                 return -EBADF;
 821         }
 822
 823         err = v9fs_t_stat(v9ses, fid->fid, &fcall);
 824
 825         if (err < 0)
 826                 dprintk(DEBUG_ERROR, "stat error\n");
 827         else {
 828                 v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
 829                                   dentry->d_inode->i_sb);
 830                 generic_fillattr(dentry->d_inode, stat);
 831         }
 832
 833         kfree(fcall);
 834         return err;
 835 }
 836
 837 /**
 838  * v9fs_vfs_setattr - set file metadata
 839  * @dentry: file whose metadata to set
 840  * @iattr: metadata assignment structure
 841  *
 842  */
 843
 844 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 845 {
 846         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 847         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 848         struct v9fs_fcall *fcall = NULL;
 849         struct v9fs_wstat wstat;
 850         int res = -EPERM;
 851
 852         dprintk(DEBUG_VFS, "\n");
 853
 854         if (!fid) {
 855                 dprintk(DEBUG_ERROR,
 856                         "Couldn't find fid associated with dentry\n");
 857                 return -EBADF;
 858         }
 859
 860         v9fs_blank_wstat(&wstat);
 861         if (iattr->ia_valid & ATTR_MODE)
 862                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 863
 864         if (iattr->ia_valid & ATTR_MTIME)
 865                 wstat.mtime = iattr->ia_mtime.tv_sec;
 866
 867         if (iattr->ia_valid & ATTR_ATIME)
 868                 wstat.atime = iattr->ia_atime.tv_sec;
 869
 870         if (iattr->ia_valid & ATTR_SIZE)
 871                 wstat.length = iattr->ia_size;
 872
 873         if (v9ses->extended) {
 874                 if (iattr->ia_valid & ATTR_UID)
 875                         wstat.n_uid = iattr->ia_uid;
 876
 877                 if (iattr->ia_valid & ATTR_GID)
 878                         wstat.n_gid = iattr->ia_gid;
 879         }
 880
 881         res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
 882
 883         if (res < 0)
 884                 PRINT_FCALL_ERROR("wstat error", fcall);
 885
 886         kfree(fcall);
 887         if (res >= 0)
 888                 res = inode_setattr(dentry->d_inode, iattr);
 889
 890         return res;
 891 }
 892
 893 /**
 894  * v9fs_stat2inode - populate an inode structure with mistat info
 895  * @stat: Plan 9 metadata (mistat) structure
 896  * @inode: inode to populate
 897  * @sb: superblock of filesystem
 898  *
 899  */
 900
 901 void
 902 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
 903         struct super_block *sb)
 904 {
 905         int n;
 906         char ext[32];
 907         struct v9fs_session_info *v9ses = sb->s_fs_info;
 908
 909         inode->i_nlink = 1;
 910
 911         inode->i_atime.tv_sec = stat->atime;
 912         inode->i_mtime.tv_sec = stat->mtime;
 913         inode->i_ctime.tv_sec = stat->mtime;
 914
 915         inode->i_uid = v9ses->uid;
 916         inode->i_gid = v9ses->gid;
 917
 918         if (v9ses->extended) {
 919                 inode->i_uid = stat->n_uid;
 920                 inode->i_gid = stat->n_gid;
 921         }
 922
 923         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 924         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 925                 char type = 0;
 926                 int major = -1;
 927                 int minor = -1;
 928
 929                 n = stat->extension.len;
 930                 if (n > sizeof(ext)-1)
 931                         n = sizeof(ext)-1;
 932                 memmove(ext, stat->extension.str, n);
 933                 ext[n] = 0;
 934                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 935                 switch (type) {
 936                 case 'c':
 937                         inode->i_mode &= ~S_IFBLK;
 938                         inode->i_mode |= S_IFCHR;
 939                         break;
 940                 case 'b':
 941                         break;
 942                 default:
 943                         dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
 944                                 type, stat->extension.len, stat->extension.str);
 945                 };
 946                 inode->i_rdev = MKDEV(major, minor);
 947         } else
 948                 inode->i_rdev = 0;
 949
 950         inode->i_size = stat->length;
 951
 952         inode->i_blocks =
 953             (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
 954 }
 955
 956 /**
 957  * v9fs_qid2ino - convert qid into inode number
 958  * @qid: qid to hash
 959  *
 960  * BUG: potential for inode number collisions?
 961  */
 962
 963 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
 964 {
 965         u64 path = qid->path + 2;
 966         ino_t i = 0;
 967
 968         if (sizeof(ino_t) == sizeof(path))
 969                 memcpy(&i, &path, sizeof(ino_t));
 970         else
 971                 i = (ino_t) (path ^ (path >> 32));
 972
 973         return i;
 974 }
 975
 976 /**
 977  * v9fs_readlink - read a symlink's location (internal version)
 978  * @dentry: dentry for symlink
 979  * @buffer: buffer to load symlink location into
 980  * @buflen: length of buffer
 981  *
 982  */
 983
 984 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 985 {
 986         int retval = -EPERM;
 987
 988         struct v9fs_fcall *fcall = NULL;
 989         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 990         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 991
 992         if (!fid) {
 993                 dprintk(DEBUG_ERROR, "could not resolve fid from dentry\n");
 994                 retval = -EBADF;
 995                 goto FreeFcall;
 996         }
 997
 998         if (!v9ses->extended) {
 999                 retval = -EBADF;
1000                 dprintk(DEBUG_ERROR, "not extended\n");
1001                 goto FreeFcall;
1002         }
1003
1004         dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
1005         retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
1006
1007         if (retval < 0) {
1008                 dprintk(DEBUG_ERROR, "stat error\n");
1009                 goto FreeFcall;
1010         }
1011
1012         if (!fcall)
1013                 return -EIO;
1014
1015         if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1016                 retval = -EINVAL;
1017                 goto FreeFcall;
1018         }
1019
1020         /* copy extension buffer into buffer */
1021         if (fcall->params.rstat.stat.extension.len < buflen)
1022                 buflen = fcall->params.rstat.stat.extension.len + 1;
1023
1024         memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1025         buffer[buflen-1] = 0;
1026
1027         dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1028                 fcall->params.rstat.stat.extension.str, buffer);
1029         retval = buflen;
1030
1031       FreeFcall:
1032         kfree(fcall);
1033
1034         return retval;
1035 }
1036
1037 /**
1038  * v9fs_vfs_readlink - read a symlink's location
1039  * @dentry: dentry for symlink
1040  * @buf: buffer to load symlink location into
1041  * @buflen: length of buffer
1042  *
1043  */
1044
1045 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1046                              int buflen)
1047 {
1048         int retval;
1049         int ret;
1050         char *link = __getname();
1051
1052         if (unlikely(!link))
1053                 return -ENOMEM;
1054
1055         if (buflen > PATH_MAX)
1056                 buflen = PATH_MAX;
1057
1058         dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1059
1060         retval = v9fs_readlink(dentry, link, buflen);
1061
1062         if (retval > 0) {
1063                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1064                         dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1065                                 ret);
1066                         retval = ret;
1067                 }
1068         }
1069
1070         __putname(link);
1071         return retval;
1072 }
1073
1074 /**
1075  * v9fs_vfs_follow_link - follow a symlink path
1076  * @dentry: dentry for symlink
1077  * @nd: nameidata
1078  *
1079  */
1080
1081 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1082 {
1083         int len = 0;
1084         char *link = __getname();
1085
1086         dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1087
1088         if (!link)
1089                 link = ERR_PTR(-ENOMEM);
1090         else {
1091                 len = v9fs_readlink(dentry, link, PATH_MAX);
1092
1093                 if (len < 0) {
1094                         __putname(link);
1095                         link = ERR_PTR(len);
1096                 } else
1097                         link[len] = 0;
1098         }
1099         nd_set_link(nd, link);
1100
1101         return NULL;
1102 }
1103
1104 /**
1105  * v9fs_vfs_put_link - release a symlink path
1106  * @dentry: dentry for symlink
1107  * @nd: nameidata
1108  *
1109  */
1110
1111 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1112 {
1113         char *s = nd_get_link(nd);
1114
1115         dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1116         if (!IS_ERR(s))
1117                 __putname(s);
1118 }
1119
1120 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1121         int mode, const char *extension)
1122 {
1123         int err;
1124         u32 fid, perm;
1125         struct v9fs_session_info *v9ses;
1126         struct v9fs_fid *dfid, *vfid;
1127         struct inode *inode;
1128
1129         inode = NULL;
1130         vfid = NULL;
1131         v9ses = v9fs_inode2v9ses(dir);
1132         dfid = v9fs_fid_lookup(dentry->d_parent);
1133         perm = unixmode2p9mode(v9ses, mode);
1134
1135         if (!v9ses->extended) {
1136                 dprintk(DEBUG_ERROR, "not extended\n");
1137                 return -EPERM;
1138         }
1139
1140         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1141                 perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1142
1143         if (err)
1144                 goto error;
1145
1146         err = v9fs_t_clunk(v9ses, fid);
1147         if (err)
1148                 goto error;
1149
1150         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1151         if (IS_ERR(vfid)) {
1152                 err = PTR_ERR(vfid);
1153                 vfid = NULL;
1154                 goto error;
1155         }
1156
1157         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1158         if (IS_ERR(inode)) {
1159                 err = PTR_ERR(inode);
1160                 inode = NULL;
1161                 goto error;
1162         }
1163
1164         dentry->d_op = &v9fs_dentry_operations;
1165         d_instantiate(dentry, inode);
1166         return 0;
1167
1168 error:
1169         if (vfid)
1170                 v9fs_fid_destroy(vfid);
1171
1172         return err;
1173
1174 }
1175
1176 /**
1177  * v9fs_vfs_symlink - helper function to create symlinks
1178  * @dir: directory inode containing symlink
1179  * @dentry: dentry for symlink
1180  * @symname: symlink data
1181  *
1182  * See 9P2000.u RFC for more information
1183  *
1184  */
1185
1186 static int
1187 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1188 {
1189         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1190                 symname);
1191
1192         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1193 }
1194
1195 /**
1196  * v9fs_vfs_link - create a hardlink
1197  * @old_dentry: dentry for file to link to
1198  * @dir: inode destination for new link
1199  * @dentry: dentry for link
1200  *
1201  */
1202
1203 /* XXX - lots of code dup'd from symlink and creates,
1204  * figure out a better reuse strategy
1205  */
1206
1207 static int
1208 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1209               struct dentry *dentry)
1210 {
1211         int retval;
1212         struct v9fs_fid *oldfid;
1213         char *name;
1214
1215         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1216                 old_dentry->d_name.name);
1217
1218         oldfid = v9fs_fid_lookup(old_dentry);
1219         if (!oldfid) {
1220                 dprintk(DEBUG_ERROR, "can't find oldfid\n");
1221                 return -EPERM;
1222         }
1223
1224         name = __getname();
1225         if (unlikely(!name))
1226                 return -ENOMEM;
1227
1228         sprintf(name, "%d\n", oldfid->fid);
1229         retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1230         __putname(name);
1231
1232         return retval;
1233 }
1234
1235 /**
1236  * v9fs_vfs_mknod - create a special file
1237  * @dir: inode destination for new link
1238  * @dentry: dentry for file
1239  * @mode: mode for creation
1240  * @dev_t: device associated with special file
1241  *
1242  */
1243
1244 static int
1245 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1246 {
1247         int retval;
1248         char *name;
1249
1250         dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1251                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1252
1253         if (!new_valid_dev(rdev))
1254                 return -EINVAL;
1255
1256         name = __getname();
1257         if (!name)
1258                 return -ENOMEM;
1259         /* build extension */
1260         if (S_ISBLK(mode))
1261                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1262         else if (S_ISCHR(mode))
1263                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1264         else if (S_ISFIFO(mode))
1265                 *name = 0;
1266         else {
1267                 __putname(name);
1268                 return -EINVAL;
1269         }
1270
1271         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1272         __putname(name);
1273
1274         return retval;
1275 }
1276
1277 static struct inode_operations v9fs_dir_inode_operations_ext = {
1278         .create = v9fs_vfs_create,
1279         .lookup = v9fs_vfs_lookup,
1280         .symlink = v9fs_vfs_symlink,
1281         .link = v9fs_vfs_link,
1282         .unlink = v9fs_vfs_unlink,
1283         .mkdir = v9fs_vfs_mkdir,
1284         .rmdir = v9fs_vfs_rmdir,
1285         .mknod = v9fs_vfs_mknod,
1286         .rename = v9fs_vfs_rename,
1287         .readlink = v9fs_vfs_readlink,
1288         .getattr = v9fs_vfs_getattr,
1289         .setattr = v9fs_vfs_setattr,
1290 };
1291
1292 static struct inode_operations v9fs_dir_inode_operations = {
1293         .create = v9fs_vfs_create,
1294         .lookup = v9fs_vfs_lookup,
1295         .unlink = v9fs_vfs_unlink,
1296         .mkdir = v9fs_vfs_mkdir,
1297         .rmdir = v9fs_vfs_rmdir,
1298         .mknod = v9fs_vfs_mknod,
1299         .rename = v9fs_vfs_rename,
1300         .getattr = v9fs_vfs_getattr,
1301         .setattr = v9fs_vfs_setattr,
1302 };
1303
1304 static struct inode_operations v9fs_file_inode_operations = {
1305         .getattr = v9fs_vfs_getattr,
1306         .setattr = v9fs_vfs_setattr,
1307 };
1308
1309 static struct inode_operations v9fs_symlink_inode_operations = {
1310         .readlink = v9fs_vfs_readlink,
1311         .follow_link = v9fs_vfs_follow_link,
1312         .put_link = v9fs_vfs_put_link,
1313         .getattr = v9fs_vfs_getattr,
1314         .setattr = v9fs_vfs_setattr,
1315 };