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 as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to:
  21  *  Free Software Foundation
  22  *  51 Franklin Street, Fifth Floor
  23  *  Boston, MA  02111-1301  USA
  24  *
  25  */
  26
  27 #include <linux/module.h>
  28 #include <linux/errno.h>
  29 #include <linux/fs.h>
  30 #include <linux/file.h>
  31 #include <linux/pagemap.h>
  32 #include <linux/stat.h>
  33 #include <linux/string.h>
  34 #include <linux/smp_lock.h>
  35 #include <linux/inet.h>
  36 #include <linux/namei.h>
  37 #include <linux/idr.h>
  38
  39 #include "debug.h"
  40 #include "v9fs.h"
  41 #include "9p.h"
  42 #include "v9fs_vfs.h"
  43 #include "fid.h"
  44
  45 static struct inode_operations v9fs_dir_inode_operations;
  46 static struct inode_operations v9fs_dir_inode_operations_ext;
  47 static struct inode_operations v9fs_file_inode_operations;
  48 static struct inode_operations v9fs_symlink_inode_operations;
  49
  50 /**
  51  * unixmode2p9mode - convert unix mode bits to plan 9
  52  * @v9ses: v9fs session information
  53  * @mode: mode to convert
  54  *
  55  */
  56
  57 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
  58 {
  59         int res;
  60         res = mode & 0777;
  61         if (S_ISDIR(mode))
  62                 res |= V9FS_DMDIR;
  63         if (v9ses->extended) {
  64                 if (S_ISLNK(mode))
  65                         res |= V9FS_DMSYMLINK;
  66                 if (v9ses->nodev == 0) {
  67                         if (S_ISSOCK(mode))
  68                                 res |= V9FS_DMSOCKET;
  69                         if (S_ISFIFO(mode))
  70                                 res |= V9FS_DMNAMEDPIPE;
  71                         if (S_ISBLK(mode))
  72                                 res |= V9FS_DMDEVICE;
  73                         if (S_ISCHR(mode))
  74                                 res |= V9FS_DMDEVICE;
  75                 }
  76
  77                 if ((mode & S_ISUID) == S_ISUID)
  78                         res |= V9FS_DMSETUID;
  79                 if ((mode & S_ISGID) == S_ISGID)
  80                         res |= V9FS_DMSETGID;
  81                 if ((mode & V9FS_DMLINK))
  82                         res |= V9FS_DMLINK;
  83         }
  84
  85         return res;
  86 }
  87
  88 /**
  89  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  90  * @v9ses: v9fs session information
  91  * @mode: mode to convert
  92  *
  93  */
  94
  95 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
  96 {
  97         int res;
  98
  99         res = mode & 0777;
 100
 101         if ((mode & V9FS_DMDIR) == V9FS_DMDIR)
 102                 res |= S_IFDIR;
 103         else if ((mode & V9FS_DMSYMLINK) && (v9ses->extended))
 104                 res |= S_IFLNK;
 105         else if ((mode & V9FS_DMSOCKET) && (v9ses->extended)
 106                  && (v9ses->nodev == 0))
 107                 res |= S_IFSOCK;
 108         else if ((mode & V9FS_DMNAMEDPIPE) && (v9ses->extended)
 109                  && (v9ses->nodev == 0))
 110                 res |= S_IFIFO;
 111         else if ((mode & V9FS_DMDEVICE) && (v9ses->extended)
 112                  && (v9ses->nodev == 0))
 113                 res |= S_IFBLK;
 114         else
 115                 res |= S_IFREG;
 116
 117         if (v9ses->extended) {
 118                 if ((mode & V9FS_DMSETUID) == V9FS_DMSETUID)
 119                         res |= S_ISUID;
 120
 121                 if ((mode & V9FS_DMSETGID) == V9FS_DMSETGID)
 122                         res |= S_ISGID;
 123         }
 124
 125         return res;
 126 }
 127
 128 int v9fs_uflags2omode(int uflags)
 129 {
 130         int ret;
 131
 132         ret = 0;
 133         switch (uflags&3) {
 134         default:
 135         case O_RDONLY:
 136                 ret = V9FS_OREAD;
 137                 break;
 138
 139         case O_WRONLY:
 140                 ret = V9FS_OWRITE;
 141                 break;
 142
 143         case O_RDWR:
 144                 ret = V9FS_ORDWR;
 145                 break;
 146         }
 147
 148         if (uflags & O_EXCL)
 149                 ret |= V9FS_OEXCL;
 150
 151         if (uflags & O_TRUNC)
 152                 ret |= V9FS_OTRUNC;
 153
 154         if (uflags & O_APPEND)
 155                 ret |= V9FS_OAPPEND;
 156
 157         return ret;
 158 }
 159
 160 /**
 161  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 162  * @v9ses: 9P session info (for determining extended mode)
 163  * @wstat: structure to initialize
 164  *
 165  */
 166
 167 static void
 168 v9fs_blank_wstat(struct v9fs_wstat *wstat)
 169 {
 170         wstat->type = ~0;
 171         wstat->dev = ~0;
 172         wstat->qid.type = ~0;
 173         wstat->qid.version = ~0;
 174         *((long long *)&wstat->qid.path) = ~0;
 175         wstat->mode = ~0;
 176         wstat->atime = ~0;
 177         wstat->mtime = ~0;
 178         wstat->length = ~0;
 179         wstat->name = NULL;
 180         wstat->uid = NULL;
 181         wstat->gid = NULL;
 182         wstat->muid = NULL;
 183         wstat->n_uid = ~0;
 184         wstat->n_gid = ~0;
 185         wstat->n_muid = ~0;
 186         wstat->extension = NULL;
 187 }
 188
 189 /**
 190  * v9fs_get_inode - helper function to setup an inode
 191  * @sb: superblock
 192  * @mode: mode to setup inode with
 193  *
 194  */
 195
 196 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 197 {
 198         struct inode *inode;
 199         struct v9fs_session_info *v9ses = sb->s_fs_info;
 200
 201         dprintk(DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 202
 203         inode = new_inode(sb);
 204         if (inode) {
 205                 inode->i_mode = mode;
 206                 inode->i_uid = current->fsuid;
 207                 inode->i_gid = current->fsgid;
 208                 inode->i_blksize = sb->s_blocksize;
 209                 inode->i_blocks = 0;
 210                 inode->i_rdev = 0;
 211                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 212                 inode->i_mapping->a_ops = &v9fs_addr_operations;
 213
 214                 switch (mode & S_IFMT) {
 215                 case S_IFIFO:
 216                 case S_IFBLK:
 217                 case S_IFCHR:
 218                 case S_IFSOCK:
 219                         if(!v9ses->extended) {
 220                                 dprintk(DEBUG_ERROR, "special files without extended mode\n");
 221                                 return ERR_PTR(-EINVAL);
 222                         }
 223                         init_special_inode(inode, inode->i_mode,
 224                                            inode->i_rdev);
 225                         break;
 226                 case S_IFREG:
 227                         inode->i_op = &v9fs_file_inode_operations;
 228                         inode->i_fop = &v9fs_file_operations;
 229                         break;
 230                 case S_IFLNK:
 231                         if(!v9ses->extended) {
 232                                 dprintk(DEBUG_ERROR, "extended modes used w/o 9P2000.u\n");
 233                                 return ERR_PTR(-EINVAL);
 234                         }
 235                         inode->i_op = &v9fs_symlink_inode_operations;
 236                         break;
 237                 case S_IFDIR:
 238                         inode->i_nlink++;
 239                         if(v9ses->extended)
 240                                 inode->i_op = &v9fs_dir_inode_operations_ext;
 241                         else
 242                                 inode->i_op = &v9fs_dir_inode_operations;
 243                         inode->i_fop = &v9fs_dir_operations;
 244                         break;
 245                 default:
 246                         dprintk(DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
 247                                 mode, mode & S_IFMT);
 248                         return ERR_PTR(-EINVAL);
 249                 }
 250         } else {
 251                 eprintk(KERN_WARNING, "Problem allocating inode\n");
 252                 return ERR_PTR(-ENOMEM);
 253         }
 254         return inode;
 255 }
 256
 257 static int
 258 v9fs_create(struct v9fs_session_info *v9ses, u32 pfid, char *name, u32 perm,
 259         u8 mode, char *extension, u32 *fidp, struct v9fs_qid *qid, u32 *iounit)
 260 {
 261         u32 fid;
 262         int err;
 263         struct v9fs_fcall *fcall;
 264
 265         fid = v9fs_get_idpool(&v9ses->fidpool);
 266         if (fid < 0) {
 267                 eprintk(KERN_WARNING, "no free fids available\n");
 268                 return -ENOSPC;
 269         }
 270
 271         err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall);
 272         if (err < 0) {
 273                 PRINT_FCALL_ERROR("clone error", fcall);
 274                 goto put_fid;
 275         }
 276         kfree(fcall);
 277
 278         err = v9fs_t_create(v9ses, fid, name, perm, mode, extension, &fcall);
 279         if (err < 0) {
 280                 PRINT_FCALL_ERROR("create fails", fcall);
 281                 goto clunk_fid;
 282         }
 283
 284         if (iounit)
 285                 *iounit = fcall->params.rcreate.iounit;
 286
 287         if (qid)
 288                 *qid = fcall->params.rcreate.qid;
 289
 290         if (fidp)
 291                 *fidp = fid;
 292
 293         kfree(fcall);
 294         return 0;
 295
 296 clunk_fid:
 297         v9fs_t_clunk(v9ses, fid);
 298         fid = V9FS_NOFID;
 299
 300 put_fid:
 301         if (fid >= 0)
 302                 v9fs_put_idpool(fid, &v9ses->fidpool);
 303
 304         kfree(fcall);
 305         return err;
 306 }
 307
 308 static struct v9fs_fid*
 309 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 310 {
 311         int err;
 312         u32 nfid;
 313         struct v9fs_fid *ret;
 314         struct v9fs_fcall *fcall;
 315
 316         nfid = v9fs_get_idpool(&v9ses->fidpool);
 317         if (nfid < 0) {
 318                 eprintk(KERN_WARNING, "no free fids available\n");
 319                 return ERR_PTR(-ENOSPC);
 320         }
 321
 322         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 323                 &fcall);
 324
 325         if (err < 0) {
 326                 PRINT_FCALL_ERROR("walk error", fcall);
 327                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 328                 goto error;
 329         }
 330
 331         kfree(fcall);
 332         fcall = NULL;
 333         ret = v9fs_fid_create(v9ses, nfid);
 334         if (!ret) {
 335                 err = -ENOMEM;
 336                 goto clunk_fid;
 337         }
 338
 339         err = v9fs_fid_insert(ret, dentry);
 340         if (err < 0) {
 341                 v9fs_fid_destroy(ret);
 342                 goto clunk_fid;
 343         }
 344
 345         return ret;
 346
 347 clunk_fid:
 348         v9fs_t_clunk(v9ses, nfid);
 349
 350 error:
 351         kfree(fcall);
 352         return ERR_PTR(err);
 353 }
 354
 355 static struct inode *
 356 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid,
 357         struct super_block *sb)
 358 {
 359         int err, umode;
 360         struct inode *ret;
 361         struct v9fs_fcall *fcall;
 362
 363         ret = NULL;
 364         err = v9fs_t_stat(v9ses, fid, &fcall);
 365         if (err) {
 366                 PRINT_FCALL_ERROR("stat error", fcall);
 367                 goto error;
 368         }
 369
 370         umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode);
 371         ret = v9fs_get_inode(sb, umode);
 372         if (IS_ERR(ret)) {
 373                 err = PTR_ERR(ret);
 374                 ret = NULL;
 375                 goto error;
 376         }
 377
 378         v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb);
 379         kfree(fcall);
 380         return ret;
 381
 382 error:
 383         kfree(fcall);
 384         if (ret)
 385                 iput(ret);
 386
 387         return ERR_PTR(err);
 388 }
 389
 390 /**
 391  * v9fs_remove - helper function to remove files and directories
 392  * @dir: directory inode that is being deleted
 393  * @file:  dentry that is being deleted
 394  * @rmdir: removing a directory
 395  *
 396  */
 397
 398 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 399 {
 400         struct v9fs_fcall *fcall = NULL;
 401         struct super_block *sb = NULL;
 402         struct v9fs_session_info *v9ses = NULL;
 403         struct v9fs_fid *v9fid = NULL;
 404         struct inode *file_inode = NULL;
 405         int fid = -1;
 406         int result = 0;
 407
 408         dprintk(DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 409                 rmdir);
 410
 411         file_inode = file->d_inode;
 412         sb = file_inode->i_sb;
 413         v9ses = v9fs_inode2v9ses(file_inode);
 414         v9fid = v9fs_fid_lookup(file);
 415
 416         if (!v9fid) {
 417                 dprintk(DEBUG_ERROR,
 418                         "no v9fs_fid\n");
 419                 return -EBADF;
 420         }
 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         } else {
 433                 v9fs_put_idpool(fid, &v9ses->fidpool);
 434                 v9fs_fid_destroy(v9fid);
 435         }
 436
 437         kfree(fcall);
 438         return result;
 439 }
 440
 441 static int
 442 v9fs_open_created(struct inode *inode, struct file *file)
 443 {
 444         return 0;
 445 }
 446
 447 /**
 448  * v9fs_vfs_create - VFS hook to create files
 449  * @inode: directory inode that is being deleted
 450  * @dentry:  dentry that is being deleted
 451  * @mode: create permissions
 452  * @nd: path information
 453  *
 454  */
 455
 456 static int
 457 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 458                 struct nameidata *nd)
 459 {
 460         int err;
 461         u32 fid, perm, iounit;
 462         int flags;
 463         struct v9fs_session_info *v9ses;
 464         struct v9fs_fid *dfid, *vfid, *ffid;
 465         struct inode *inode;
 466         struct v9fs_qid qid;
 467         struct file *filp;
 468
 469         inode = NULL;
 470         vfid = NULL;
 471         v9ses = v9fs_inode2v9ses(dir);
 472         dfid = v9fs_fid_lookup(dentry->d_parent);
 473         perm = unixmode2p9mode(v9ses, mode);
 474
 475         if (nd && nd->flags & LOOKUP_OPEN)
 476                 flags = nd->intent.open.flags - 1;
 477         else
 478                 flags = O_RDWR;
 479
 480         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 481                 perm, v9fs_uflags2omode(flags), NULL, &fid, &qid, &iounit);
 482
 483         if (err)
 484                 goto error;
 485
 486         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 487         if (IS_ERR(vfid)) {
 488                 err = PTR_ERR(vfid);
 489                 vfid = NULL;
 490                 goto error;
 491         }
 492
 493         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 494         if (IS_ERR(inode)) {
 495                 err = PTR_ERR(inode);
 496                 inode = NULL;
 497                 goto error;
 498         }
 499
 500         dentry->d_op = &v9fs_dentry_operations;
 501         d_instantiate(dentry, inode);
 502
 503         if (nd && nd->flags & LOOKUP_OPEN) {
 504                 ffid = v9fs_fid_create(v9ses, fid);
 505                 if (!ffid)
 506                         return -ENOMEM;
 507
 508                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 509                 if (IS_ERR(filp)) {
 510                         v9fs_fid_destroy(ffid);
 511                         return PTR_ERR(filp);
 512                 }
 513
 514                 ffid->rdir_pos = 0;
 515                 ffid->rdir_fcall = NULL;
 516                 ffid->fidopen = 1;
 517                 ffid->iounit = iounit;
 518                 ffid->filp = filp;
 519                 filp->private_data = ffid;
 520         }
 521
 522         return 0;
 523
 524 error:
 525         if (vfid)
 526                 v9fs_fid_destroy(vfid);
 527
 528         if (inode)
 529                 iput(inode);
 530
 531         return err;
 532 }
 533
 534 /**
 535  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 536  * @inode:  inode that is being unlinked
 537  * @dentry: dentry that is being unlinked
 538  * @mode: mode for new directory
 539  *
 540  */
 541
 542 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 543 {
 544         int err;
 545         u32 fid, perm;
 546         struct v9fs_session_info *v9ses;
 547         struct v9fs_fid *dfid, *vfid;
 548         struct inode *inode;
 549
 550         inode = NULL;
 551         vfid = NULL;
 552         v9ses = v9fs_inode2v9ses(dir);
 553         dfid = v9fs_fid_lookup(dentry->d_parent);
 554         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 555
 556         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 557                 perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
 558
 559         if (err) {
 560                 dprintk(DEBUG_ERROR, "create error %d\n", err);
 561                 goto error;
 562         }
 563
 564         err = v9fs_t_clunk(v9ses, fid);
 565         if (err) {
 566                 dprintk(DEBUG_ERROR, "clunk error %d\n", err);
 567                 goto error;
 568         }
 569
 570         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 571         if (IS_ERR(vfid)) {
 572                 err = PTR_ERR(vfid);
 573                 vfid = NULL;
 574                 goto error;
 575         }
 576
 577         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 578         if (IS_ERR(inode)) {
 579                 err = PTR_ERR(inode);
 580                 inode = NULL;
 581                 goto error;
 582         }
 583
 584         dentry->d_op = &v9fs_dentry_operations;
 585         d_instantiate(dentry, inode);
 586         return 0;
 587
 588 error:
 589         if (vfid)
 590                 v9fs_fid_destroy(vfid);
 591
 592         return err;
 593 }
 594
 595 /**
 596  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 597  * @dir:  inode that is being walked from
 598  * @dentry: dentry that is being walked to?
 599  * @nameidata: path data
 600  *
 601  */
 602
 603 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 604                                       struct nameidata *nameidata)
 605 {
 606         struct super_block *sb;
 607         struct v9fs_session_info *v9ses;
 608         struct v9fs_fid *dirfid;
 609         struct v9fs_fid *fid;
 610         struct inode *inode;
 611         struct v9fs_fcall *fcall = NULL;
 612         int dirfidnum = -1;
 613         int newfid = -1;
 614         int result = 0;
 615
 616         dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 617                 dir, dentry->d_name.name, dentry, nameidata);
 618
 619         sb = dir->i_sb;
 620         v9ses = v9fs_inode2v9ses(dir);
 621         dentry->d_op = &v9fs_dentry_operations;
 622         dirfid = v9fs_fid_lookup(dentry->d_parent);
 623
 624         if (!dirfid) {
 625                 dprintk(DEBUG_ERROR, "no dirfid\n");
 626                 return ERR_PTR(-EINVAL);
 627         }
 628
 629         dirfidnum = dirfid->fid;
 630
 631         if (dirfidnum < 0) {
 632                 dprintk(DEBUG_ERROR, "no dirfid for inode %p, #%lu\n",
 633                         dir, dir->i_ino);
 634                 return ERR_PTR(-EBADF);
 635         }
 636
 637         newfid = v9fs_get_idpool(&v9ses->fidpool);
 638         if (newfid < 0) {
 639                 eprintk(KERN_WARNING, "newfid fails!\n");
 640                 return ERR_PTR(-ENOSPC);
 641         }
 642
 643         result = v9fs_t_walk(v9ses, dirfidnum, newfid,
 644                 (char *)dentry->d_name.name, NULL);
 645         if (result < 0) {
 646                 v9fs_put_idpool(newfid, &v9ses->fidpool);
 647                 if (result == -ENOENT) {
 648                         d_add(dentry, NULL);
 649                         dprintk(DEBUG_VFS,
 650                                 "Return negative dentry %p count %d\n",
 651                                 dentry, atomic_read(&dentry->d_count));
 652                         return NULL;
 653                 }
 654                 dprintk(DEBUG_ERROR, "walk error:%d\n", result);
 655                 goto FreeFcall;
 656         }
 657
 658         result = v9fs_t_stat(v9ses, newfid, &fcall);
 659         if (result < 0) {
 660                 dprintk(DEBUG_ERROR, "stat error\n");
 661                 goto FreeFcall;
 662         }
 663
 664         inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
 665                 fcall->params.rstat.stat.mode));
 666
 667         if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
 668                 eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
 669                         PTR_ERR(inode));
 670
 671                 result = -ENOSPC;
 672                 goto FreeFcall;
 673         }
 674
 675         inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
 676
 677         fid = v9fs_fid_create(v9ses, newfid);
 678         if (fid == NULL) {
 679                 dprintk(DEBUG_ERROR, "couldn't insert\n");
 680                 result = -ENOMEM;
 681                 goto FreeFcall;
 682         }
 683
 684         result = v9fs_fid_insert(fid, dentry);
 685         if (result < 0)
 686                 goto FreeFcall;
 687
 688         fid->qid = fcall->params.rstat.stat.qid;
 689         v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
 690
 691         d_add(dentry, inode);
 692         kfree(fcall);
 693
 694         return NULL;
 695
 696       FreeFcall:
 697         kfree(fcall);
 698         return ERR_PTR(result);
 699 }
 700
 701 /**
 702  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 703  * @i:  inode that is being unlinked
 704  * @d: dentry that is being unlinked
 705  *
 706  */
 707
 708 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 709 {
 710         return v9fs_remove(i, d, 0);
 711 }
 712
 713 /**
 714  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 715  * @i:  inode that is being unlinked
 716  * @d: dentry that is being unlinked
 717  *
 718  */
 719
 720 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 721 {
 722         return v9fs_remove(i, d, 1);
 723 }
 724
 725 /**
 726  * v9fs_vfs_rename - VFS hook to rename an inode
 727  * @old_dir:  old dir inode
 728  * @old_dentry: old dentry
 729  * @new_dir: new dir inode
 730  * @new_dentry: new dentry
 731  *
 732  */
 733
 734 static int
 735 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 736                 struct inode *new_dir, struct dentry *new_dentry)
 737 {
 738         struct inode *old_inode = old_dentry->d_inode;
 739         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
 740         struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
 741         struct v9fs_fid *olddirfid =
 742             v9fs_fid_lookup(old_dentry->d_parent);
 743         struct v9fs_fid *newdirfid =
 744             v9fs_fid_lookup(new_dentry->d_parent);
 745         struct v9fs_wstat wstat;
 746         struct v9fs_fcall *fcall = NULL;
 747         int fid = -1;
 748         int olddirfidnum = -1;
 749         int newdirfidnum = -1;
 750         int retval = 0;
 751
 752         dprintk(DEBUG_VFS, "\n");
 753
 754         if ((!oldfid) || (!olddirfid) || (!newdirfid)) {
 755                 dprintk(DEBUG_ERROR, "problem with arguments\n");
 756                 return -EBADF;
 757         }
 758
 759         /* 9P can only handle file rename in the same directory */
 760         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 761                 dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
 762                 retval = -EPERM;
 763                 goto FreeFcallnBail;
 764         }
 765
 766         fid = oldfid->fid;
 767         olddirfidnum = olddirfid->fid;
 768         newdirfidnum = newdirfid->fid;
 769
 770         if (fid < 0) {
 771                 dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
 772                         old_inode->i_ino);
 773                 retval = -EBADF;
 774                 goto FreeFcallnBail;
 775         }
 776
 777         v9fs_blank_wstat(&wstat);
 778         wstat.muid = v9ses->name;
 779         wstat.name = (char *) new_dentry->d_name.name;
 780
 781         retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
 782
 783       FreeFcallnBail:
 784         if (retval < 0)
 785                 PRINT_FCALL_ERROR("wstat error", fcall);
 786
 787         kfree(fcall);
 788         return retval;
 789 }
 790
 791 /**
 792  * v9fs_vfs_getattr - retrieve file metadata
 793  * @mnt - mount information
 794  * @dentry - file to get attributes on
 795  * @stat - metadata structure to populate
 796  *
 797  */
 798
 799 static int
 800 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 801                  struct kstat *stat)
 802 {
 803         struct v9fs_fcall *fcall = NULL;
 804         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 805         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 806         int err = -EPERM;
 807
 808         dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
 809         if (!fid) {
 810                 dprintk(DEBUG_ERROR,
 811                         "couldn't find fid associated with dentry\n");
 812                 return -EBADF;
 813         }
 814
 815         err = v9fs_t_stat(v9ses, fid->fid, &fcall);
 816
 817         if (err < 0)
 818                 dprintk(DEBUG_ERROR, "stat error\n");
 819         else {
 820                 v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
 821                                   dentry->d_inode->i_sb);
 822                 generic_fillattr(dentry->d_inode, stat);
 823         }
 824
 825         kfree(fcall);
 826         return err;
 827 }
 828
 829 /**
 830  * v9fs_vfs_setattr - set file metadata
 831  * @dentry: file whose metadata to set
 832  * @iattr: metadata assignment structure
 833  *
 834  */
 835
 836 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 837 {
 838         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 839         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 840         struct v9fs_fcall *fcall = NULL;
 841         struct v9fs_wstat wstat;
 842         int res = -EPERM;
 843
 844         dprintk(DEBUG_VFS, "\n");
 845
 846         if (!fid) {
 847                 dprintk(DEBUG_ERROR,
 848                         "Couldn't find fid associated with dentry\n");
 849                 return -EBADF;
 850         }
 851
 852         v9fs_blank_wstat(&wstat);
 853         if (iattr->ia_valid & ATTR_MODE)
 854                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 855
 856         if (iattr->ia_valid & ATTR_MTIME)
 857                 wstat.mtime = iattr->ia_mtime.tv_sec;
 858
 859         if (iattr->ia_valid & ATTR_ATIME)
 860                 wstat.atime = iattr->ia_atime.tv_sec;
 861
 862         if (iattr->ia_valid & ATTR_SIZE)
 863                 wstat.length = iattr->ia_size;
 864
 865         if (v9ses->extended) {
 866                 if (iattr->ia_valid & ATTR_UID)
 867                         wstat.n_uid = iattr->ia_uid;
 868
 869                 if (iattr->ia_valid & ATTR_GID)
 870                         wstat.n_gid = iattr->ia_gid;
 871         }
 872
 873         res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
 874
 875         if (res < 0)
 876                 PRINT_FCALL_ERROR("wstat error", fcall);
 877
 878         kfree(fcall);
 879         if (res >= 0)
 880                 res = inode_setattr(dentry->d_inode, iattr);
 881
 882         return res;
 883 }
 884
 885 /**
 886  * v9fs_stat2inode - populate an inode structure with mistat info
 887  * @stat: Plan 9 metadata (mistat) structure
 888  * @inode: inode to populate
 889  * @sb: superblock of filesystem
 890  *
 891  */
 892
 893 void
 894 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
 895         struct super_block *sb)
 896 {
 897         int n;
 898         char ext[32];
 899         struct v9fs_session_info *v9ses = sb->s_fs_info;
 900
 901         inode->i_nlink = 1;
 902
 903         inode->i_atime.tv_sec = stat->atime;
 904         inode->i_mtime.tv_sec = stat->mtime;
 905         inode->i_ctime.tv_sec = stat->mtime;
 906
 907         inode->i_uid = v9ses->uid;
 908         inode->i_gid = v9ses->gid;
 909
 910         if (v9ses->extended) {
 911                 inode->i_uid = stat->n_uid;
 912                 inode->i_gid = stat->n_gid;
 913         }
 914
 915         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 916         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 917                 char type = 0;
 918                 int major = -1;
 919                 int minor = -1;
 920
 921                 n = stat->extension.len;
 922                 if (n > sizeof(ext)-1)
 923                         n = sizeof(ext)-1;
 924                 memmove(ext, stat->extension.str, n);
 925                 ext[n] = 0;
 926                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 927                 switch (type) {
 928                 case 'c':
 929                         inode->i_mode &= ~S_IFBLK;
 930                         inode->i_mode |= S_IFCHR;
 931                         break;
 932                 case 'b':
 933                         break;
 934                 default:
 935                         dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
 936                                 type, stat->extension.len, stat->extension.str);
 937                 };
 938                 inode->i_rdev = MKDEV(major, minor);
 939         } else
 940                 inode->i_rdev = 0;
 941
 942         inode->i_size = stat->length;
 943
 944         inode->i_blksize = sb->s_blocksize;
 945         inode->i_blocks =
 946             (inode->i_size + inode->i_blksize - 1) >> sb->s_blocksize_bits;
 947 }
 948
 949 /**
 950  * v9fs_qid2ino - convert qid into inode number
 951  * @qid: qid to hash
 952  *
 953  * BUG: potential for inode number collisions?
 954  */
 955
 956 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
 957 {
 958         u64 path = qid->path + 2;
 959         ino_t i = 0;
 960
 961         if (sizeof(ino_t) == sizeof(path))
 962                 memcpy(&i, &path, sizeof(ino_t));
 963         else
 964                 i = (ino_t) (path ^ (path >> 32));
 965
 966         return i;
 967 }
 968
 969 /**
 970  * v9fs_readlink - read a symlink's location (internal version)
 971  * @dentry: dentry for symlink
 972  * @buffer: buffer to load symlink location into
 973  * @buflen: length of buffer
 974  *
 975  */
 976
 977 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 978 {
 979         int retval = -EPERM;
 980
 981         struct v9fs_fcall *fcall = NULL;
 982         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 983         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 984
 985         if (!fid) {
 986                 dprintk(DEBUG_ERROR, "could not resolve fid from dentry\n");
 987                 retval = -EBADF;
 988                 goto FreeFcall;
 989         }
 990
 991         if (!v9ses->extended) {
 992                 retval = -EBADF;
 993                 dprintk(DEBUG_ERROR, "not extended\n");
 994                 goto FreeFcall;
 995         }
 996
 997         dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
 998         retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
 999
1000         if (retval < 0) {
1001                 dprintk(DEBUG_ERROR, "stat error\n");
1002                 goto FreeFcall;
1003         }
1004
1005         if (!fcall)
1006                 return -EIO;
1007
1008         if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1009                 retval = -EINVAL;
1010                 goto FreeFcall;
1011         }
1012
1013         /* copy extension buffer into buffer */
1014         if (fcall->params.rstat.stat.extension.len < buflen)
1015                 buflen = fcall->params.rstat.stat.extension.len + 1;
1016
1017         memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1018         buffer[buflen-1] = 0;
1019
1020         dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1021                 fcall->params.rstat.stat.extension.str, buffer);
1022         retval = buflen;
1023
1024       FreeFcall:
1025         kfree(fcall);
1026
1027         return retval;
1028 }
1029
1030 /**
1031  * v9fs_vfs_readlink - read a symlink's location
1032  * @dentry: dentry for symlink
1033  * @buf: buffer to load symlink location into
1034  * @buflen: length of buffer
1035  *
1036  */
1037
1038 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1039                              int buflen)
1040 {
1041         int retval;
1042         int ret;
1043         char *link = __getname();
1044
1045         if (buflen > PATH_MAX)
1046                 buflen = PATH_MAX;
1047
1048         dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1049
1050         retval = v9fs_readlink(dentry, link, buflen);
1051
1052         if (retval > 0) {
1053                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1054                         dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1055                                 ret);
1056                         retval = ret;
1057                 }
1058         }
1059
1060         __putname(link);
1061         return retval;
1062 }
1063
1064 /**
1065  * v9fs_vfs_follow_link - follow a symlink path
1066  * @dentry: dentry for symlink
1067  * @nd: nameidata
1068  *
1069  */
1070
1071 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1072 {
1073         int len = 0;
1074         char *link = __getname();
1075
1076         dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1077
1078         if (!link)
1079                 link = ERR_PTR(-ENOMEM);
1080         else {
1081                 len = v9fs_readlink(dentry, link, PATH_MAX);
1082
1083                 if (len < 0) {
1084                         __putname(link);
1085                         link = ERR_PTR(len);
1086                 } else
1087                         link[len] = 0;
1088         }
1089         nd_set_link(nd, link);
1090
1091         return NULL;
1092 }
1093
1094 /**
1095  * v9fs_vfs_put_link - release a symlink path
1096  * @dentry: dentry for symlink
1097  * @nd: nameidata
1098  *
1099  */
1100
1101 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1102 {
1103         char *s = nd_get_link(nd);
1104
1105         dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1106         if (!IS_ERR(s))
1107                 __putname(s);
1108 }
1109
1110 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1111         int mode, const char *extension)
1112 {
1113         int err;
1114         u32 fid, perm;
1115         struct v9fs_session_info *v9ses;
1116         struct v9fs_fid *dfid, *vfid;
1117         struct inode *inode;
1118
1119         inode = NULL;
1120         vfid = NULL;
1121         v9ses = v9fs_inode2v9ses(dir);
1122         dfid = v9fs_fid_lookup(dentry->d_parent);
1123         perm = unixmode2p9mode(v9ses, mode);
1124
1125         if (!v9ses->extended) {
1126                 dprintk(DEBUG_ERROR, "not extended\n");
1127                 return -EPERM;
1128         }
1129
1130         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1131                 perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1132
1133         if (err)
1134                 goto error;
1135
1136         err = v9fs_t_clunk(v9ses, fid);
1137         if (err)
1138                 goto error;
1139
1140         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1141         if (IS_ERR(vfid)) {
1142                 err = PTR_ERR(vfid);
1143                 vfid = NULL;
1144                 goto error;
1145         }
1146
1147         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1148         if (IS_ERR(inode)) {
1149                 err = PTR_ERR(inode);
1150                 inode = NULL;
1151                 goto error;
1152         }
1153
1154         dentry->d_op = &v9fs_dentry_operations;
1155         d_instantiate(dentry, inode);
1156         return 0;
1157
1158 error:
1159         if (vfid)
1160                 v9fs_fid_destroy(vfid);
1161
1162         if (inode)
1163                 iput(inode);
1164
1165         return err;
1166
1167 }
1168
1169 /**
1170  * v9fs_vfs_symlink - helper function to create symlinks
1171  * @dir: directory inode containing symlink
1172  * @dentry: dentry for symlink
1173  * @symname: symlink data
1174  *
1175  * See 9P2000.u RFC for more information
1176  *
1177  */
1178
1179 static int
1180 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1181 {
1182         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1183                 symname);
1184
1185         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1186 }
1187
1188 /**
1189  * v9fs_vfs_link - create a hardlink
1190  * @old_dentry: dentry for file to link to
1191  * @dir: inode destination for new link
1192  * @dentry: dentry for link
1193  *
1194  */
1195
1196 /* XXX - lots of code dup'd from symlink and creates,
1197  * figure out a better reuse strategy
1198  */
1199
1200 static int
1201 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1202               struct dentry *dentry)
1203 {
1204         int retval;
1205         struct v9fs_fid *oldfid;
1206         char *name;
1207
1208         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1209                 old_dentry->d_name.name);
1210
1211         oldfid = v9fs_fid_lookup(old_dentry);
1212         if (!oldfid) {
1213                 dprintk(DEBUG_ERROR, "can't find oldfid\n");
1214                 return -EPERM;
1215         }
1216
1217         name = __getname();
1218         sprintf(name, "%d\n", oldfid->fid);
1219         retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1220         __putname(name);
1221
1222         return retval;
1223 }
1224
1225 /**
1226  * v9fs_vfs_mknod - create a special file
1227  * @dir: inode destination for new link
1228  * @dentry: dentry for file
1229  * @mode: mode for creation
1230  * @dev_t: device associated with special file
1231  *
1232  */
1233
1234 static int
1235 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1236 {
1237         int retval;
1238         char *name;
1239
1240         dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1241                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1242
1243         if (!new_valid_dev(rdev))
1244                 return -EINVAL;
1245
1246         name = __getname();
1247         if (!name)
1248                 return -ENOMEM;
1249         /* build extension */
1250         if (S_ISBLK(mode))
1251                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1252         else if (S_ISCHR(mode))
1253                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1254         else if (S_ISFIFO(mode))
1255                 *name = 0;
1256         else {
1257                 __putname(name);
1258                 return -EINVAL;
1259         }
1260
1261         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1262         __putname(name);
1263
1264         return retval;
1265 }
1266
1267 static struct inode_operations v9fs_dir_inode_operations_ext = {
1268         .create = v9fs_vfs_create,
1269         .lookup = v9fs_vfs_lookup,
1270         .symlink = v9fs_vfs_symlink,
1271         .link = v9fs_vfs_link,
1272         .unlink = v9fs_vfs_unlink,
1273         .mkdir = v9fs_vfs_mkdir,
1274         .rmdir = v9fs_vfs_rmdir,
1275         .mknod = v9fs_vfs_mknod,
1276         .rename = v9fs_vfs_rename,
1277         .readlink = v9fs_vfs_readlink,
1278         .getattr = v9fs_vfs_getattr,
1279         .setattr = v9fs_vfs_setattr,
1280 };
1281
1282 static struct inode_operations v9fs_dir_inode_operations = {
1283         .create = v9fs_vfs_create,
1284         .lookup = v9fs_vfs_lookup,
1285         .unlink = v9fs_vfs_unlink,
1286         .mkdir = v9fs_vfs_mkdir,
1287         .rmdir = v9fs_vfs_rmdir,
1288         .mknod = v9fs_vfs_mknod,
1289         .rename = v9fs_vfs_rename,
1290         .getattr = v9fs_vfs_getattr,
1291         .setattr = v9fs_vfs_setattr,
1292 };
1293
1294 static struct inode_operations v9fs_file_inode_operations = {
1295         .getattr = v9fs_vfs_getattr,
1296         .setattr = v9fs_vfs_setattr,
1297 };
1298
1299 static struct inode_operations v9fs_symlink_inode_operations = {
1300         .readlink = v9fs_vfs_readlink,
1301         .follow_link = v9fs_vfs_follow_link,
1302         .put_link = v9fs_vfs_put_link,
1303         .getattr = v9fs_vfs_getattr,
1304         .setattr = v9fs_vfs_setattr,
1305 };