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,
 259         u32 perm, u8 mode, 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 error;
 275         }
 276         kfree(fcall);
 277
 278         err = v9fs_t_create(v9ses, fid, name, perm, mode, &fcall);
 279         if (err < 0) {
 280                 PRINT_FCALL_ERROR("create fails", fcall);
 281                 goto error;
 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 error:
 297         if (fid >= 0)
 298                 v9fs_put_idpool(fid, &v9ses->fidpool);
 299
 300         kfree(fcall);
 301         return err;
 302 }
 303
 304 static struct v9fs_fid*
 305 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 306 {
 307         int err;
 308         u32 nfid;
 309         struct v9fs_fid *ret;
 310         struct v9fs_fcall *fcall;
 311
 312         nfid = v9fs_get_idpool(&v9ses->fidpool);
 313         if (nfid < 0) {
 314                 eprintk(KERN_WARNING, "no free fids available\n");
 315                 return ERR_PTR(-ENOSPC);
 316         }
 317
 318         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 319                 &fcall);
 320
 321         if (err < 0) {
 322                 PRINT_FCALL_ERROR("walk error", fcall);
 323                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 324                 goto error;
 325         }
 326
 327         kfree(fcall);
 328         fcall = NULL;
 329         ret = v9fs_fid_create(v9ses, nfid);
 330         if (!ret) {
 331                 err = -ENOMEM;
 332                 goto clunk_fid;
 333         }
 334
 335         err = v9fs_fid_insert(ret, dentry);
 336         if (err < 0) {
 337                 v9fs_fid_destroy(ret);
 338                 goto clunk_fid;
 339         }
 340
 341         return ret;
 342
 343 clunk_fid:
 344         v9fs_t_clunk(v9ses, nfid);
 345
 346 error:
 347         kfree(fcall);
 348         return ERR_PTR(err);
 349 }
 350
 351 struct inode *
 352 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid,
 353         struct super_block *sb)
 354 {
 355         int err, umode;
 356         struct inode *ret;
 357         struct v9fs_fcall *fcall;
 358
 359         ret = NULL;
 360         err = v9fs_t_stat(v9ses, fid, &fcall);
 361         if (err) {
 362                 PRINT_FCALL_ERROR("stat error", fcall);
 363                 goto error;
 364         }
 365
 366         umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode);
 367         ret = v9fs_get_inode(sb, umode);
 368         if (IS_ERR(ret)) {
 369                 err = PTR_ERR(ret);
 370                 ret = NULL;
 371                 goto error;
 372         }
 373
 374         v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb);
 375         kfree(fcall);
 376         return ret;
 377
 378 error:
 379         kfree(fcall);
 380         if (ret)
 381                 iput(ret);
 382
 383         return ERR_PTR(err);
 384 }
 385
 386 /**
 387  * v9fs_remove - helper function to remove files and directories
 388  * @dir: directory inode that is being deleted
 389  * @file:  dentry that is being deleted
 390  * @rmdir: removing a directory
 391  *
 392  */
 393
 394 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 395 {
 396         struct v9fs_fcall *fcall = NULL;
 397         struct super_block *sb = NULL;
 398         struct v9fs_session_info *v9ses = NULL;
 399         struct v9fs_fid *v9fid = NULL;
 400         struct inode *file_inode = NULL;
 401         int fid = -1;
 402         int result = 0;
 403
 404         dprintk(DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 405                 rmdir);
 406
 407         file_inode = file->d_inode;
 408         sb = file_inode->i_sb;
 409         v9ses = v9fs_inode2v9ses(file_inode);
 410         v9fid = v9fs_fid_lookup(file);
 411
 412         if (!v9fid) {
 413                 dprintk(DEBUG_ERROR,
 414                         "no v9fs_fid\n");
 415                 return -EBADF;
 416         }
 417
 418         fid = v9fid->fid;
 419         if (fid < 0) {
 420                 dprintk(DEBUG_ERROR, "inode #%lu, no fid!\n",
 421                         file_inode->i_ino);
 422                 return -EBADF;
 423         }
 424
 425         result = v9fs_t_remove(v9ses, fid, &fcall);
 426         if (result < 0) {
 427                 PRINT_FCALL_ERROR("remove fails", fcall);
 428         } else {
 429                 v9fs_put_idpool(fid, &v9ses->fidpool);
 430                 v9fs_fid_destroy(v9fid);
 431         }
 432
 433         kfree(fcall);
 434         return result;
 435 }
 436
 437 static int
 438 v9fs_open_created(struct inode *inode, struct file *file)
 439 {
 440         return 0;
 441 }
 442
 443 /**
 444  * v9fs_vfs_create - VFS hook to create files
 445  * @inode: directory inode that is being deleted
 446  * @dentry:  dentry that is being deleted
 447  * @mode: create permissions
 448  * @nd: path information
 449  *
 450  */
 451
 452 static int
 453 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 454                 struct nameidata *nd)
 455 {
 456         int err;
 457         u32 fid, perm, iounit;
 458         int flags;
 459         struct v9fs_session_info *v9ses;
 460         struct v9fs_fid *dfid, *vfid, *ffid;
 461         struct inode *inode;
 462         struct v9fs_qid qid;
 463         struct file *filp;
 464
 465         inode = NULL;
 466         vfid = NULL;
 467         v9ses = v9fs_inode2v9ses(dir);
 468         dfid = v9fs_fid_lookup(dentry->d_parent);
 469         perm = unixmode2p9mode(v9ses, mode);
 470
 471         if (nd && nd->flags & LOOKUP_OPEN)
 472                 flags = nd->intent.open.flags - 1;
 473         else
 474                 flags = O_RDWR;
 475
 476         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 477                 perm, v9fs_uflags2omode(flags), &fid, &qid, &iounit);
 478
 479         if (err)
 480                 goto error;
 481
 482         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 483         if (IS_ERR(vfid)) {
 484                 err = PTR_ERR(vfid);
 485                 vfid = NULL;
 486                 goto error;
 487         }
 488
 489         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 490         if (IS_ERR(inode)) {
 491                 err = PTR_ERR(inode);
 492                 inode = NULL;
 493                 goto error;
 494         }
 495
 496         dentry->d_op = &v9fs_dentry_operations;
 497         d_instantiate(dentry, inode);
 498
 499         if (nd && nd->flags & LOOKUP_OPEN) {
 500                 ffid = v9fs_fid_create(v9ses, fid);
 501                 if (!ffid)
 502                         return -ENOMEM;
 503
 504                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 505                 if (IS_ERR(filp)) {
 506                         v9fs_fid_destroy(ffid);
 507                         return PTR_ERR(filp);
 508                 }
 509
 510                 ffid->rdir_pos = 0;
 511                 ffid->rdir_fcall = NULL;
 512                 ffid->fidopen = 1;
 513                 ffid->iounit = iounit;
 514                 ffid->filp = filp;
 515                 filp->private_data = ffid;
 516         }
 517
 518         return 0;
 519
 520 error:
 521         if (vfid)
 522                 v9fs_fid_destroy(vfid);
 523
 524         if (inode)
 525                 iput(inode);
 526
 527         return err;
 528 }
 529
 530 /**
 531  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 532  * @inode:  inode that is being unlinked
 533  * @dentry: dentry that is being unlinked
 534  * @mode: mode for new directory
 535  *
 536  */
 537
 538 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 539 {
 540         int err;
 541         u32 fid, perm;
 542         struct v9fs_session_info *v9ses;
 543         struct v9fs_fid *dfid, *vfid;
 544         struct inode *inode;
 545
 546         inode = NULL;
 547         vfid = NULL;
 548         v9ses = v9fs_inode2v9ses(dir);
 549         dfid = v9fs_fid_lookup(dentry->d_parent);
 550         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 551
 552         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 553                 perm, V9FS_OREAD, &fid, NULL, NULL);
 554
 555         if (err) {
 556                 dprintk(DEBUG_ERROR, "create error %d\n", err);
 557                 goto error;
 558         }
 559
 560         err = v9fs_t_clunk(v9ses, fid);
 561         if (err) {
 562                 dprintk(DEBUG_ERROR, "clunk error %d\n", err);
 563                 goto error;
 564         }
 565
 566         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 567         if (IS_ERR(vfid)) {
 568                 err = PTR_ERR(vfid);
 569                 vfid = NULL;
 570                 goto error;
 571         }
 572
 573         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 574         if (IS_ERR(inode)) {
 575                 err = PTR_ERR(inode);
 576                 inode = NULL;
 577                 goto error;
 578         }
 579
 580         dentry->d_op = &v9fs_dentry_operations;
 581         d_instantiate(dentry, inode);
 582         return 0;
 583
 584 error:
 585         if (vfid)
 586                 v9fs_fid_destroy(vfid);
 587
 588         return err;
 589 }
 590
 591 /**
 592  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 593  * @dir:  inode that is being walked from
 594  * @dentry: dentry that is being walked to?
 595  * @nameidata: path data
 596  *
 597  */
 598
 599 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 600                                       struct nameidata *nameidata)
 601 {
 602         struct super_block *sb;
 603         struct v9fs_session_info *v9ses;
 604         struct v9fs_fid *dirfid;
 605         struct v9fs_fid *fid;
 606         struct inode *inode;
 607         struct v9fs_fcall *fcall = NULL;
 608         int dirfidnum = -1;
 609         int newfid = -1;
 610         int result = 0;
 611
 612         dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 613                 dir, dentry->d_name.name, dentry, nameidata);
 614
 615         sb = dir->i_sb;
 616         v9ses = v9fs_inode2v9ses(dir);
 617         dentry->d_op = &v9fs_dentry_operations;
 618         dirfid = v9fs_fid_lookup(dentry->d_parent);
 619
 620         if (!dirfid) {
 621                 dprintk(DEBUG_ERROR, "no dirfid\n");
 622                 return ERR_PTR(-EINVAL);
 623         }
 624
 625         dirfidnum = dirfid->fid;
 626
 627         if (dirfidnum < 0) {
 628                 dprintk(DEBUG_ERROR, "no dirfid for inode %p, #%lu\n",
 629                         dir, dir->i_ino);
 630                 return ERR_PTR(-EBADF);
 631         }
 632
 633         newfid = v9fs_get_idpool(&v9ses->fidpool);
 634         if (newfid < 0) {
 635                 eprintk(KERN_WARNING, "newfid fails!\n");
 636                 return ERR_PTR(-ENOSPC);
 637         }
 638
 639         result = v9fs_t_walk(v9ses, dirfidnum, newfid,
 640                 (char *)dentry->d_name.name, NULL);
 641         if (result < 0) {
 642                 v9fs_put_idpool(newfid, &v9ses->fidpool);
 643                 if (result == -ENOENT) {
 644                         d_add(dentry, NULL);
 645                         dprintk(DEBUG_VFS,
 646                                 "Return negative dentry %p count %d\n",
 647                                 dentry, atomic_read(&dentry->d_count));
 648                         return NULL;
 649                 }
 650                 dprintk(DEBUG_ERROR, "walk error:%d\n", result);
 651                 goto FreeFcall;
 652         }
 653
 654         result = v9fs_t_stat(v9ses, newfid, &fcall);
 655         if (result < 0) {
 656                 dprintk(DEBUG_ERROR, "stat error\n");
 657                 goto FreeFcall;
 658         }
 659
 660         inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
 661                 fcall->params.rstat.stat.mode));
 662
 663         if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
 664                 eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
 665                         PTR_ERR(inode));
 666
 667                 result = -ENOSPC;
 668                 goto FreeFcall;
 669         }
 670
 671         inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
 672
 673         fid = v9fs_fid_create(v9ses, newfid);
 674         if (fid == NULL) {
 675                 dprintk(DEBUG_ERROR, "couldn't insert\n");
 676                 result = -ENOMEM;
 677                 goto FreeFcall;
 678         }
 679
 680         result = v9fs_fid_insert(fid, dentry);
 681         if (result < 0)
 682                 goto FreeFcall;
 683
 684         fid->qid = fcall->params.rstat.stat.qid;
 685         v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
 686
 687         d_add(dentry, inode);
 688         kfree(fcall);
 689
 690         return NULL;
 691
 692       FreeFcall:
 693         kfree(fcall);
 694         return ERR_PTR(result);
 695 }
 696
 697 /**
 698  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 699  * @i:  inode that is being unlinked
 700  * @d: dentry that is being unlinked
 701  *
 702  */
 703
 704 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 705 {
 706         return v9fs_remove(i, d, 0);
 707 }
 708
 709 /**
 710  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 711  * @i:  inode that is being unlinked
 712  * @d: dentry that is being unlinked
 713  *
 714  */
 715
 716 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 717 {
 718         return v9fs_remove(i, d, 1);
 719 }
 720
 721 /**
 722  * v9fs_vfs_rename - VFS hook to rename an inode
 723  * @old_dir:  old dir inode
 724  * @old_dentry: old dentry
 725  * @new_dir: new dir inode
 726  * @new_dentry: new dentry
 727  *
 728  */
 729
 730 static int
 731 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 732                 struct inode *new_dir, struct dentry *new_dentry)
 733 {
 734         struct inode *old_inode = old_dentry->d_inode;
 735         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
 736         struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
 737         struct v9fs_fid *olddirfid =
 738             v9fs_fid_lookup(old_dentry->d_parent);
 739         struct v9fs_fid *newdirfid =
 740             v9fs_fid_lookup(new_dentry->d_parent);
 741         struct v9fs_wstat wstat;
 742         struct v9fs_fcall *fcall = NULL;
 743         int fid = -1;
 744         int olddirfidnum = -1;
 745         int newdirfidnum = -1;
 746         int retval = 0;
 747
 748         dprintk(DEBUG_VFS, "\n");
 749
 750         if ((!oldfid) || (!olddirfid) || (!newdirfid)) {
 751                 dprintk(DEBUG_ERROR, "problem with arguments\n");
 752                 return -EBADF;
 753         }
 754
 755         /* 9P can only handle file rename in the same directory */
 756         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 757                 dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
 758                 retval = -EPERM;
 759                 goto FreeFcallnBail;
 760         }
 761
 762         fid = oldfid->fid;
 763         olddirfidnum = olddirfid->fid;
 764         newdirfidnum = newdirfid->fid;
 765
 766         if (fid < 0) {
 767                 dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
 768                         old_inode->i_ino);
 769                 retval = -EBADF;
 770                 goto FreeFcallnBail;
 771         }
 772
 773         v9fs_blank_wstat(&wstat);
 774         wstat.muid = v9ses->name;
 775         wstat.name = (char *) new_dentry->d_name.name;
 776
 777         retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
 778
 779       FreeFcallnBail:
 780         if (retval < 0)
 781                 PRINT_FCALL_ERROR("wstat error", fcall);
 782
 783         kfree(fcall);
 784         return retval;
 785 }
 786
 787 /**
 788  * v9fs_vfs_getattr - retrieve file metadata
 789  * @mnt - mount information
 790  * @dentry - file to get attributes on
 791  * @stat - metadata structure to populate
 792  *
 793  */
 794
 795 static int
 796 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 797                  struct kstat *stat)
 798 {
 799         struct v9fs_fcall *fcall = NULL;
 800         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 801         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 802         int err = -EPERM;
 803
 804         dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
 805         if (!fid) {
 806                 dprintk(DEBUG_ERROR,
 807                         "couldn't find fid associated with dentry\n");
 808                 return -EBADF;
 809         }
 810
 811         err = v9fs_t_stat(v9ses, fid->fid, &fcall);
 812
 813         if (err < 0)
 814                 dprintk(DEBUG_ERROR, "stat error\n");
 815         else {
 816                 v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
 817                                   dentry->d_inode->i_sb);
 818                 generic_fillattr(dentry->d_inode, stat);
 819         }
 820
 821         kfree(fcall);
 822         return err;
 823 }
 824
 825 /**
 826  * v9fs_vfs_setattr - set file metadata
 827  * @dentry: file whose metadata to set
 828  * @iattr: metadata assignment structure
 829  *
 830  */
 831
 832 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 833 {
 834         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 835         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 836         struct v9fs_fcall *fcall = NULL;
 837         struct v9fs_wstat wstat;
 838         int res = -EPERM;
 839
 840         dprintk(DEBUG_VFS, "\n");
 841
 842         if (!fid) {
 843                 dprintk(DEBUG_ERROR,
 844                         "Couldn't find fid associated with dentry\n");
 845                 return -EBADF;
 846         }
 847
 848         v9fs_blank_wstat(&wstat);
 849         if (iattr->ia_valid & ATTR_MODE)
 850                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 851
 852         if (iattr->ia_valid & ATTR_MTIME)
 853                 wstat.mtime = iattr->ia_mtime.tv_sec;
 854
 855         if (iattr->ia_valid & ATTR_ATIME)
 856                 wstat.atime = iattr->ia_atime.tv_sec;
 857
 858         if (iattr->ia_valid & ATTR_SIZE)
 859                 wstat.length = iattr->ia_size;
 860
 861         if (v9ses->extended) {
 862                 if (iattr->ia_valid & ATTR_UID)
 863                         wstat.n_uid = iattr->ia_uid;
 864
 865                 if (iattr->ia_valid & ATTR_GID)
 866                         wstat.n_gid = iattr->ia_gid;
 867         }
 868
 869         res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
 870
 871         if (res < 0)
 872                 PRINT_FCALL_ERROR("wstat error", fcall);
 873
 874         kfree(fcall);
 875         if (res >= 0)
 876                 res = inode_setattr(dentry->d_inode, iattr);
 877
 878         return res;
 879 }
 880
 881 /**
 882  * v9fs_stat2inode - populate an inode structure with mistat info
 883  * @stat: Plan 9 metadata (mistat) structure
 884  * @inode: inode to populate
 885  * @sb: superblock of filesystem
 886  *
 887  */
 888
 889 void
 890 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
 891         struct super_block *sb)
 892 {
 893         int n;
 894         char ext[32];
 895         struct v9fs_session_info *v9ses = sb->s_fs_info;
 896
 897         inode->i_nlink = 1;
 898
 899         inode->i_atime.tv_sec = stat->atime;
 900         inode->i_mtime.tv_sec = stat->mtime;
 901         inode->i_ctime.tv_sec = stat->mtime;
 902
 903         inode->i_uid = v9ses->uid;
 904         inode->i_gid = v9ses->gid;
 905
 906         if (v9ses->extended) {
 907                 inode->i_uid = stat->n_uid;
 908                 inode->i_gid = stat->n_gid;
 909         }
 910
 911         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 912         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 913                 char type = 0;
 914                 int major = -1;
 915                 int minor = -1;
 916
 917                 n = stat->extension.len;
 918                 if (n > sizeof(ext)-1)
 919                         n = sizeof(ext)-1;
 920                 memmove(ext, stat->extension.str, n);
 921                 ext[n] = 0;
 922                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 923                 switch (type) {
 924                 case 'c':
 925                         inode->i_mode &= ~S_IFBLK;
 926                         inode->i_mode |= S_IFCHR;
 927                         break;
 928                 case 'b':
 929                         break;
 930                 default:
 931                         dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
 932                                 type, stat->extension.len, stat->extension.str);
 933                 };
 934                 inode->i_rdev = MKDEV(major, minor);
 935         } else
 936                 inode->i_rdev = 0;
 937
 938         inode->i_size = stat->length;
 939
 940         inode->i_blksize = sb->s_blocksize;
 941         inode->i_blocks =
 942             (inode->i_size + inode->i_blksize - 1) >> sb->s_blocksize_bits;
 943 }
 944
 945 /**
 946  * v9fs_qid2ino - convert qid into inode number
 947  * @qid: qid to hash
 948  *
 949  * BUG: potential for inode number collisions?
 950  */
 951
 952 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
 953 {
 954         u64 path = qid->path + 2;
 955         ino_t i = 0;
 956
 957         if (sizeof(ino_t) == sizeof(path))
 958                 memcpy(&i, &path, sizeof(ino_t));
 959         else
 960                 i = (ino_t) (path ^ (path >> 32));
 961
 962         return i;
 963 }
 964
 965 /**
 966  * v9fs_readlink - read a symlink's location (internal version)
 967  * @dentry: dentry for symlink
 968  * @buffer: buffer to load symlink location into
 969  * @buflen: length of buffer
 970  *
 971  */
 972
 973 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 974 {
 975         int retval = -EPERM;
 976
 977         struct v9fs_fcall *fcall = NULL;
 978         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 979         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 980
 981         if (!fid) {
 982                 dprintk(DEBUG_ERROR, "could not resolve fid from dentry\n");
 983                 retval = -EBADF;
 984                 goto FreeFcall;
 985         }
 986
 987         if (!v9ses->extended) {
 988                 retval = -EBADF;
 989                 dprintk(DEBUG_ERROR, "not extended\n");
 990                 goto FreeFcall;
 991         }
 992
 993         dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
 994         retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
 995
 996         if (retval < 0) {
 997                 dprintk(DEBUG_ERROR, "stat error\n");
 998                 goto FreeFcall;
 999         }
1000
1001         if (!fcall)
1002                 return -EIO;
1003
1004         if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1005                 retval = -EINVAL;
1006                 goto FreeFcall;
1007         }
1008
1009         /* copy extension buffer into buffer */
1010         if (fcall->params.rstat.stat.extension.len < buflen)
1011                 buflen = fcall->params.rstat.stat.extension.len;
1012
1013         memcpy(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1014         buffer[buflen-1] = 0;
1015
1016         retval = buflen;
1017
1018       FreeFcall:
1019         kfree(fcall);
1020
1021         return retval;
1022 }
1023
1024 /**
1025  * v9fs_vfs_readlink - read a symlink's location
1026  * @dentry: dentry for symlink
1027  * @buf: buffer to load symlink location into
1028  * @buflen: length of buffer
1029  *
1030  */
1031
1032 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1033                              int buflen)
1034 {
1035         int retval;
1036         int ret;
1037         char *link = __getname();
1038
1039         if (buflen > PATH_MAX)
1040                 buflen = PATH_MAX;
1041
1042         dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1043
1044         retval = v9fs_readlink(dentry, link, buflen);
1045
1046         if (retval > 0) {
1047                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1048                         dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1049                                 ret);
1050                         retval = ret;
1051                 }
1052         }
1053
1054         __putname(link);
1055         return retval;
1056 }
1057
1058 /**
1059  * v9fs_vfs_follow_link - follow a symlink path
1060  * @dentry: dentry for symlink
1061  * @nd: nameidata
1062  *
1063  */
1064
1065 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1066 {
1067         int len = 0;
1068         char *link = __getname();
1069
1070         dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1071
1072         if (!link)
1073                 link = ERR_PTR(-ENOMEM);
1074         else {
1075                 len = v9fs_readlink(dentry, link, strlen(link));
1076
1077                 if (len < 0) {
1078                         __putname(link);
1079                         link = ERR_PTR(len);
1080                 } else
1081                         link[len] = 0;
1082         }
1083         nd_set_link(nd, link);
1084
1085         return NULL;
1086 }
1087
1088 /**
1089  * v9fs_vfs_put_link - release a symlink path
1090  * @dentry: dentry for symlink
1091  * @nd: nameidata
1092  *
1093  */
1094
1095 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1096 {
1097         char *s = nd_get_link(nd);
1098
1099         dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1100         if (!IS_ERR(s))
1101                 __putname(s);
1102 }
1103
1104 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1105         int mode, const char *extension)
1106 {
1107         int err;
1108         u32 fid, perm;
1109         struct v9fs_session_info *v9ses;
1110         struct v9fs_fid *dfid, *vfid;
1111         struct inode *inode;
1112         struct v9fs_fcall *fcall;
1113         struct v9fs_wstat wstat;
1114
1115         fcall = NULL;
1116         inode = NULL;
1117         vfid = NULL;
1118         v9ses = v9fs_inode2v9ses(dir);
1119         dfid = v9fs_fid_lookup(dentry->d_parent);
1120         perm = unixmode2p9mode(v9ses, mode);
1121
1122         if (!v9ses->extended) {
1123                 dprintk(DEBUG_ERROR, "not extended\n");
1124                 return -EPERM;
1125         }
1126
1127         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1128                 perm, V9FS_OREAD, &fid, NULL, NULL);
1129
1130         if (err)
1131                 goto error;
1132
1133         err = v9fs_t_clunk(v9ses, fid);
1134         if (err)
1135                 goto error;
1136
1137         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1138         if (IS_ERR(vfid)) {
1139                 err = PTR_ERR(vfid);
1140                 vfid = NULL;
1141                 goto error;
1142         }
1143
1144         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1145         if (IS_ERR(inode)) {
1146                 err = PTR_ERR(inode);
1147                 inode = NULL;
1148                 goto error;
1149         }
1150
1151         /* issue a Twstat */
1152         v9fs_blank_wstat(&wstat);
1153         wstat.muid = v9ses->name;
1154         wstat.extension = (char *) extension;
1155         err = v9fs_t_wstat(v9ses, vfid->fid, &wstat, &fcall);
1156         if (err < 0) {
1157                 PRINT_FCALL_ERROR("wstat error", fcall);
1158                 goto error;
1159         }
1160
1161         kfree(fcall);
1162         dentry->d_op = &v9fs_dentry_operations;
1163         d_instantiate(dentry, inode);
1164         return 0;
1165
1166 error:
1167         kfree(fcall);
1168         if (vfid)
1169                 v9fs_fid_destroy(vfid);
1170
1171         if (inode)
1172                 iput(inode);
1173
1174         return err;
1175
1176 }
1177
1178 /**
1179  * v9fs_vfs_symlink - helper function to create symlinks
1180  * @dir: directory inode containing symlink
1181  * @dentry: dentry for symlink
1182  * @symname: symlink data
1183  *
1184  * See 9P2000.u RFC for more information
1185  *
1186  */
1187
1188 static int
1189 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1190 {
1191         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1192                 symname);
1193
1194         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1195 }
1196
1197 /**
1198  * v9fs_vfs_link - create a hardlink
1199  * @old_dentry: dentry for file to link to
1200  * @dir: inode destination for new link
1201  * @dentry: dentry for link
1202  *
1203  */
1204
1205 /* XXX - lots of code dup'd from symlink and creates,
1206  * figure out a better reuse strategy
1207  */
1208
1209 static int
1210 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1211               struct dentry *dentry)
1212 {
1213         int retval;
1214         struct v9fs_fid *oldfid;
1215         char *name;
1216
1217         dprintk(DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1218                 old_dentry->d_name.name);
1219
1220         oldfid = v9fs_fid_lookup(old_dentry);
1221         if (!oldfid) {
1222                 dprintk(DEBUG_ERROR, "can't find oldfid\n");
1223                 return -EPERM;
1224         }
1225
1226         name = __getname();
1227         sprintf(name, "hardlink(%d)\n", oldfid->fid);
1228         retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1229         __putname(name);
1230
1231         return retval;
1232 }
1233
1234 /**
1235  * v9fs_vfs_mknod - create a special file
1236  * @dir: inode destination for new link
1237  * @dentry: dentry for file
1238  * @mode: mode for creation
1239  * @dev_t: device associated with special file
1240  *
1241  */
1242
1243 static int
1244 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1245 {
1246         int retval;
1247         char *name;
1248
1249         dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1250                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1251
1252         if (!new_valid_dev(rdev))
1253                 return -EINVAL;
1254
1255         name = __getname();
1256         /* build extension */
1257         if (S_ISBLK(mode))
1258                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1259         else if (S_ISCHR(mode))
1260                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1261         else if (S_ISFIFO(mode))
1262                 *name = 0;
1263         else {
1264                 __putname(name);
1265                 return -EINVAL;
1266         }
1267
1268         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1269         __putname(name);
1270
1271         return retval;
1272 }
1273
1274 static struct inode_operations v9fs_dir_inode_operations_ext = {
1275         .create = v9fs_vfs_create,
1276         .lookup = v9fs_vfs_lookup,
1277         .symlink = v9fs_vfs_symlink,
1278         .link = v9fs_vfs_link,
1279         .unlink = v9fs_vfs_unlink,
1280         .mkdir = v9fs_vfs_mkdir,
1281         .rmdir = v9fs_vfs_rmdir,
1282         .mknod = v9fs_vfs_mknod,
1283         .rename = v9fs_vfs_rename,
1284         .readlink = v9fs_vfs_readlink,
1285         .getattr = v9fs_vfs_getattr,
1286         .setattr = v9fs_vfs_setattr,
1287 };
1288
1289 static struct inode_operations v9fs_dir_inode_operations = {
1290         .create = v9fs_vfs_create,
1291         .lookup = v9fs_vfs_lookup,
1292         .unlink = v9fs_vfs_unlink,
1293         .mkdir = v9fs_vfs_mkdir,
1294         .rmdir = v9fs_vfs_rmdir,
1295         .mknod = v9fs_vfs_mknod,
1296         .rename = v9fs_vfs_rename,
1297         .getattr = v9fs_vfs_getattr,
1298         .setattr = v9fs_vfs_setattr,
1299 };
1300
1301 static struct inode_operations v9fs_file_inode_operations = {
1302         .getattr = v9fs_vfs_getattr,
1303         .setattr = v9fs_vfs_setattr,
1304 };
1305
1306 static struct inode_operations v9fs_symlink_inode_operations = {
1307         .readlink = v9fs_vfs_readlink,
1308         .follow_link = v9fs_vfs_follow_link,
1309         .put_link = v9fs_vfs_put_link,
1310         .getattr = v9fs_vfs_getattr,
1311         .setattr = v9fs_vfs_setattr,
1312 };