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/inet.h>
  34 #include <linux/namei.h>
  35 #include <linux/idr.h>
  36 #include <linux/sched.h>
  37 #include <net/9p/9p.h>
  38 #include <net/9p/client.h>
  39
  40 #include "v9fs.h"
  41 #include "v9fs_vfs.h"
  42 #include "fid.h"
  43
  44 static const struct inode_operations v9fs_dir_inode_operations;
  45 static const struct inode_operations v9fs_dir_inode_operations_ext;
  46 static const struct inode_operations v9fs_file_inode_operations;
  47 static const struct inode_operations v9fs_symlink_inode_operations;
  48
  49 /**
  50  * unixmode2p9mode - convert unix mode bits to plan 9
  51  * @v9ses: v9fs session information
  52  * @mode: mode to convert
  53  *
  54  */
  55
  56 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
  57 {
  58         int res;
  59         res = mode & 0777;
  60         if (S_ISDIR(mode))
  61                 res |= P9_DMDIR;
  62         if (v9fs_extended(v9ses)) {
  63                 if (S_ISLNK(mode))
  64                         res |= P9_DMSYMLINK;
  65                 if (v9ses->nodev == 0) {
  66                         if (S_ISSOCK(mode))
  67                                 res |= P9_DMSOCKET;
  68                         if (S_ISFIFO(mode))
  69                                 res |= P9_DMNAMEDPIPE;
  70                         if (S_ISBLK(mode))
  71                                 res |= P9_DMDEVICE;
  72                         if (S_ISCHR(mode))
  73                                 res |= P9_DMDEVICE;
  74                 }
  75
  76                 if ((mode & S_ISUID) == S_ISUID)
  77                         res |= P9_DMSETUID;
  78                 if ((mode & S_ISGID) == S_ISGID)
  79                         res |= P9_DMSETGID;
  80                 if ((mode & S_ISVTX) == S_ISVTX)
  81                         res |= P9_DMSETVTX;
  82                 if ((mode & P9_DMLINK))
  83                         res |= P9_DMLINK;
  84         }
  85
  86         return res;
  87 }
  88
  89 /**
  90  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  91  * @v9ses: v9fs session information
  92  * @mode: mode to convert
  93  *
  94  */
  95
  96 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
  97 {
  98         int res;
  99
 100         res = mode & 0777;
 101
 102         if ((mode & P9_DMDIR) == P9_DMDIR)
 103                 res |= S_IFDIR;
 104         else if ((mode & P9_DMSYMLINK) && (v9fs_extended(v9ses)))
 105                 res |= S_IFLNK;
 106         else if ((mode & P9_DMSOCKET) && (v9fs_extended(v9ses))
 107                  && (v9ses->nodev == 0))
 108                 res |= S_IFSOCK;
 109         else if ((mode & P9_DMNAMEDPIPE) && (v9fs_extended(v9ses))
 110                  && (v9ses->nodev == 0))
 111                 res |= S_IFIFO;
 112         else if ((mode & P9_DMDEVICE) && (v9fs_extended(v9ses))
 113                  && (v9ses->nodev == 0))
 114                 res |= S_IFBLK;
 115         else
 116                 res |= S_IFREG;
 117
 118         if (v9fs_extended(v9ses)) {
 119                 if ((mode & P9_DMSETUID) == P9_DMSETUID)
 120                         res |= S_ISUID;
 121
 122                 if ((mode & P9_DMSETGID) == P9_DMSETGID)
 123                         res |= S_ISGID;
 124
 125                 if ((mode & P9_DMSETVTX) == P9_DMSETVTX)
 126                         res |= S_ISVTX;
 127         }
 128
 129         return res;
 130 }
 131
 132 int v9fs_uflags2omode(int uflags)
 133 {
 134         int ret;
 135
 136         ret = 0;
 137         switch (uflags&3) {
 138         default:
 139         case O_RDONLY:
 140                 ret = P9_OREAD;
 141                 break;
 142
 143         case O_WRONLY:
 144                 ret = P9_OWRITE;
 145                 break;
 146
 147         case O_RDWR:
 148                 ret = P9_ORDWR;
 149                 break;
 150         }
 151
 152         if (uflags & O_EXCL)
 153                 ret |= P9_OEXCL;
 154
 155         if (uflags & O_TRUNC)
 156                 ret |= P9_OTRUNC;
 157
 158         if (uflags & O_APPEND)
 159                 ret |= P9_OAPPEND;
 160
 161         return ret;
 162 }
 163
 164 /**
 165  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 166  * @v9ses: 9P session info (for determining extended mode)
 167  * @wstat: structure to initialize
 168  *
 169  */
 170
 171 static void
 172 v9fs_blank_wstat(struct p9_wstat *wstat)
 173 {
 174         wstat->type = ~0;
 175         wstat->dev = ~0;
 176         wstat->qid.type = ~0;
 177         wstat->qid.version = ~0;
 178         *((long long *)&wstat->qid.path) = ~0;
 179         wstat->mode = ~0;
 180         wstat->atime = ~0;
 181         wstat->mtime = ~0;
 182         wstat->length = ~0;
 183         wstat->name = NULL;
 184         wstat->uid = NULL;
 185         wstat->gid = NULL;
 186         wstat->muid = NULL;
 187         wstat->n_uid = ~0;
 188         wstat->n_gid = ~0;
 189         wstat->n_muid = ~0;
 190         wstat->extension = NULL;
 191 }
 192
 193 /**
 194  * v9fs_get_inode - helper function to setup an inode
 195  * @sb: superblock
 196  * @mode: mode to setup inode with
 197  *
 198  */
 199
 200 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 201 {
 202         struct inode *inode;
 203         struct v9fs_session_info *v9ses = sb->s_fs_info;
 204
 205         P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 206
 207         inode = new_inode(sb);
 208         if (inode) {
 209                 inode->i_mode = mode;
 210                 inode->i_uid = current->fsuid;
 211                 inode->i_gid = current->fsgid;
 212                 inode->i_blocks = 0;
 213                 inode->i_rdev = 0;
 214                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 215                 inode->i_mapping->a_ops = &v9fs_addr_operations;
 216
 217                 switch (mode & S_IFMT) {
 218                 case S_IFIFO:
 219                 case S_IFBLK:
 220                 case S_IFCHR:
 221                 case S_IFSOCK:
 222                         if (!v9fs_extended(v9ses)) {
 223                                 P9_DPRINTK(P9_DEBUG_ERROR,
 224                                       "special files without extended mode\n");
 225                                 return ERR_PTR(-EINVAL);
 226                         }
 227                         init_special_inode(inode, inode->i_mode,
 228                                            inode->i_rdev);
 229                         break;
 230                 case S_IFREG:
 231                         inode->i_op = &v9fs_file_inode_operations;
 232                         inode->i_fop = &v9fs_file_operations;
 233                         break;
 234                 case S_IFLNK:
 235                         if (!v9fs_extended(v9ses)) {
 236                                 P9_DPRINTK(P9_DEBUG_ERROR,
 237                                         "extended modes used w/o 9P2000.u\n");
 238                                 return ERR_PTR(-EINVAL);
 239                         }
 240                         inode->i_op = &v9fs_symlink_inode_operations;
 241                         break;
 242                 case S_IFDIR:
 243                         inc_nlink(inode);
 244                         if (v9fs_extended(v9ses))
 245                                 inode->i_op = &v9fs_dir_inode_operations_ext;
 246                         else
 247                                 inode->i_op = &v9fs_dir_inode_operations;
 248                         inode->i_fop = &v9fs_dir_operations;
 249                         break;
 250                 default:
 251                         P9_DPRINTK(P9_DEBUG_ERROR,
 252                                 "BAD mode 0x%x S_IFMT 0x%x\n",
 253                                 mode, mode & S_IFMT);
 254                         return ERR_PTR(-EINVAL);
 255                 }
 256         } else {
 257                 P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n");
 258                 return ERR_PTR(-ENOMEM);
 259         }
 260         return inode;
 261 }
 262
 263 /*
 264 static struct v9fs_fid*
 265 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 266 {
 267         int err;
 268         int nfid;
 269         struct v9fs_fid *ret;
 270         struct v9fs_fcall *fcall;
 271
 272         nfid = v9fs_get_idpool(&v9ses->fidpool);
 273         if (nfid < 0) {
 274                 eprintk(KERN_WARNING, "no free fids available\n");
 275                 return ERR_PTR(-ENOSPC);
 276         }
 277
 278         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 279                 &fcall);
 280
 281         if (err < 0) {
 282                 if (fcall && fcall->id == RWALK)
 283                         goto clunk_fid;
 284
 285                 PRINT_FCALL_ERROR("walk error", fcall);
 286                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 287                 goto error;
 288         }
 289
 290         kfree(fcall);
 291         fcall = NULL;
 292         ret = v9fs_fid_create(v9ses, nfid);
 293         if (!ret) {
 294                 err = -ENOMEM;
 295                 goto clunk_fid;
 296         }
 297
 298         err = v9fs_fid_insert(ret, dentry);
 299         if (err < 0) {
 300                 v9fs_fid_destroy(ret);
 301                 goto clunk_fid;
 302         }
 303
 304         return ret;
 305
 306 clunk_fid:
 307         v9fs_t_clunk(v9ses, nfid);
 308
 309 error:
 310         kfree(fcall);
 311         return ERR_PTR(err);
 312 }
 313 */
 314
 315 static struct inode *
 316 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid,
 317         struct super_block *sb)
 318 {
 319         int err, umode;
 320         struct inode *ret;
 321         struct p9_stat *st;
 322
 323         ret = NULL;
 324         st = p9_client_stat(fid);
 325         if (IS_ERR(st)) {
 326                 err = PTR_ERR(st);
 327                 st = NULL;
 328                 goto error;
 329         }
 330
 331         umode = p9mode2unixmode(v9ses, st->mode);
 332         ret = v9fs_get_inode(sb, umode);
 333         if (IS_ERR(ret)) {
 334                 err = PTR_ERR(ret);
 335                 ret = NULL;
 336                 goto error;
 337         }
 338
 339         v9fs_stat2inode(st, ret, sb);
 340         ret->i_ino = v9fs_qid2ino(&st->qid);
 341         kfree(st);
 342         return ret;
 343
 344 error:
 345         kfree(st);
 346         if (ret)
 347                 iput(ret);
 348
 349         return ERR_PTR(err);
 350 }
 351
 352 /**
 353  * v9fs_remove - helper function to remove files and directories
 354  * @dir: directory inode that is being deleted
 355  * @file:  dentry that is being deleted
 356  * @rmdir: removing a directory
 357  *
 358  */
 359
 360 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 361 {
 362         struct inode *file_inode;
 363         struct v9fs_session_info *v9ses;
 364         struct p9_fid *v9fid;
 365
 366         P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 367                 rmdir);
 368
 369         file_inode = file->d_inode;
 370         v9ses = v9fs_inode2v9ses(file_inode);
 371         v9fid = v9fs_fid_clone(file);
 372         if (IS_ERR(v9fid))
 373                 return PTR_ERR(v9fid);
 374
 375         return p9_client_remove(v9fid);
 376 }
 377
 378 static int
 379 v9fs_open_created(struct inode *inode, struct file *file)
 380 {
 381         return 0;
 382 }
 383
 384
 385 /**
 386  * v9fs_create - Create a file
 387  * @dentry:  dentry that is being created
 388  * @perm: create permissions
 389  * @mode: open mode
 390  *
 391  */
 392 static struct p9_fid *
 393 v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir,
 394                 struct dentry *dentry, char *extension, u32 perm, u8 mode)
 395 {
 396         int err;
 397         char *name;
 398         struct p9_fid *dfid, *ofid, *fid;
 399         struct inode *inode;
 400
 401         err = 0;
 402         ofid = NULL;
 403         fid = NULL;
 404         name = (char *) dentry->d_name.name;
 405         dfid = v9fs_fid_clone(dentry->d_parent);
 406         if (IS_ERR(dfid)) {
 407                 err = PTR_ERR(dfid);
 408                 dfid = NULL;
 409                 goto error;
 410         }
 411
 412         /* clone a fid to use for creation */
 413         ofid = p9_client_walk(dfid, 0, NULL, 1);
 414         if (IS_ERR(ofid)) {
 415                 err = PTR_ERR(ofid);
 416                 ofid = NULL;
 417                 goto error;
 418         }
 419
 420         err = p9_client_fcreate(ofid, name, perm, mode, extension);
 421         if (err < 0)
 422                 goto error;
 423
 424         /* now walk from the parent so we can get unopened fid */
 425         fid = p9_client_walk(dfid, 1, &name, 0);
 426         if (IS_ERR(fid)) {
 427                 err = PTR_ERR(fid);
 428                 fid = NULL;
 429                 goto error;
 430         } else
 431                 dfid = NULL;
 432
 433         /* instantiate inode and assign the unopened fid to the dentry */
 434         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 435         if (IS_ERR(inode)) {
 436                 err = PTR_ERR(inode);
 437                 goto error;
 438         }
 439
 440         if (v9ses->cache)
 441                 dentry->d_op = &v9fs_cached_dentry_operations;
 442         else
 443                 dentry->d_op = &v9fs_dentry_operations;
 444
 445         d_instantiate(dentry, inode);
 446         v9fs_fid_add(dentry, fid);
 447         return ofid;
 448
 449 error:
 450         if (dfid)
 451                 p9_client_clunk(dfid);
 452
 453         if (ofid)
 454                 p9_client_clunk(ofid);
 455
 456         if (fid)
 457                 p9_client_clunk(fid);
 458
 459         return ERR_PTR(err);
 460 }
 461
 462 /**
 463  * v9fs_vfs_create - VFS hook to create files
 464  * @inode: directory inode that is being created
 465  * @dentry:  dentry that is being deleted
 466  * @mode: create permissions
 467  * @nd: path information
 468  *
 469  */
 470
 471 static int
 472 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 473                 struct nameidata *nd)
 474 {
 475         int err;
 476         u32 perm;
 477         int flags;
 478         struct v9fs_session_info *v9ses;
 479         struct p9_fid *fid;
 480         struct file *filp;
 481
 482         err = 0;
 483         fid = NULL;
 484         v9ses = v9fs_inode2v9ses(dir);
 485         perm = unixmode2p9mode(v9ses, mode);
 486         if (nd && nd->flags & LOOKUP_OPEN)
 487                 flags = nd->intent.open.flags - 1;
 488         else
 489                 flags = O_RDWR;
 490
 491         fid = v9fs_create(v9ses, dir, dentry, NULL, perm,
 492                                                 v9fs_uflags2omode(flags));
 493         if (IS_ERR(fid)) {
 494                 err = PTR_ERR(fid);
 495                 fid = NULL;
 496                 goto error;
 497         }
 498
 499         /* if we are opening a file, assign the open fid to the file */
 500         if (nd && nd->flags & LOOKUP_OPEN) {
 501                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 502                 if (IS_ERR(filp)) {
 503                         err = PTR_ERR(filp);
 504                         goto error;
 505                 }
 506
 507                 filp->private_data = fid;
 508         } else
 509                 p9_client_clunk(fid);
 510
 511         return 0;
 512
 513 error:
 514         if (fid)
 515                 p9_client_clunk(fid);
 516
 517         return err;
 518 }
 519
 520 /**
 521  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 522  * @inode:  inode that is being unlinked
 523  * @dentry: dentry that is being unlinked
 524  * @mode: mode for new directory
 525  *
 526  */
 527
 528 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 529 {
 530         int err;
 531         u32 perm;
 532         struct v9fs_session_info *v9ses;
 533         struct p9_fid *fid;
 534
 535         P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name);
 536         err = 0;
 537         v9ses = v9fs_inode2v9ses(dir);
 538         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 539         fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD);
 540         if (IS_ERR(fid)) {
 541                 err = PTR_ERR(fid);
 542                 fid = NULL;
 543         }
 544
 545         if (fid)
 546                 p9_client_clunk(fid);
 547
 548         return err;
 549 }
 550
 551 /**
 552  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 553  * @dir:  inode that is being walked from
 554  * @dentry: dentry that is being walked to?
 555  * @nameidata: path data
 556  *
 557  */
 558
 559 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 560                                       struct nameidata *nameidata)
 561 {
 562         struct super_block *sb;
 563         struct v9fs_session_info *v9ses;
 564         struct p9_fid *dfid, *fid;
 565         struct inode *inode;
 566         char *name;
 567         int result = 0;
 568
 569         P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 570                 dir, dentry->d_name.name, dentry, nameidata);
 571
 572         sb = dir->i_sb;
 573         v9ses = v9fs_inode2v9ses(dir);
 574         dfid = v9fs_fid_lookup(dentry->d_parent);
 575         if (IS_ERR(dfid))
 576                 return ERR_CAST(dfid);
 577
 578         name = (char *) dentry->d_name.name;
 579         fid = p9_client_walk(dfid, 1, &name, 1);
 580         if (IS_ERR(fid)) {
 581                 result = PTR_ERR(fid);
 582                 if (result == -ENOENT) {
 583                         d_add(dentry, NULL);
 584                         return NULL;
 585                 }
 586
 587                 return ERR_PTR(result);
 588         }
 589
 590         inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb);
 591         if (IS_ERR(inode)) {
 592                 result = PTR_ERR(inode);
 593                 inode = NULL;
 594                 goto error;
 595         }
 596
 597         result = v9fs_fid_add(dentry, fid);
 598         if (result < 0)
 599                 goto error;
 600
 601         if ((fid->qid.version) && (v9ses->cache))
 602                 dentry->d_op = &v9fs_cached_dentry_operations;
 603         else
 604                 dentry->d_op = &v9fs_dentry_operations;
 605
 606         d_add(dentry, inode);
 607         return NULL;
 608
 609 error:
 610         if (fid)
 611                 p9_client_clunk(fid);
 612
 613         return ERR_PTR(result);
 614 }
 615
 616 /**
 617  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 618  * @i:  inode that is being unlinked
 619  * @d: dentry that is being unlinked
 620  *
 621  */
 622
 623 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 624 {
 625         return v9fs_remove(i, d, 0);
 626 }
 627
 628 /**
 629  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 630  * @i:  inode that is being unlinked
 631  * @d: dentry that is being unlinked
 632  *
 633  */
 634
 635 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 636 {
 637         return v9fs_remove(i, d, 1);
 638 }
 639
 640 /**
 641  * v9fs_vfs_rename - VFS hook to rename an inode
 642  * @old_dir:  old dir inode
 643  * @old_dentry: old dentry
 644  * @new_dir: new dir inode
 645  * @new_dentry: new dentry
 646  *
 647  */
 648
 649 static int
 650 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 651                 struct inode *new_dir, struct dentry *new_dentry)
 652 {
 653         struct inode *old_inode;
 654         struct v9fs_session_info *v9ses;
 655         struct p9_fid *oldfid;
 656         struct p9_fid *olddirfid;
 657         struct p9_fid *newdirfid;
 658         struct p9_wstat wstat;
 659         int retval;
 660
 661         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 662         retval = 0;
 663         old_inode = old_dentry->d_inode;
 664         v9ses = v9fs_inode2v9ses(old_inode);
 665         oldfid = v9fs_fid_lookup(old_dentry);
 666         if (IS_ERR(oldfid))
 667                 return PTR_ERR(oldfid);
 668
 669         olddirfid = v9fs_fid_clone(old_dentry->d_parent);
 670         if (IS_ERR(olddirfid)) {
 671                 retval = PTR_ERR(olddirfid);
 672                 goto done;
 673         }
 674
 675         newdirfid = v9fs_fid_clone(new_dentry->d_parent);
 676         if (IS_ERR(newdirfid)) {
 677                 retval = PTR_ERR(newdirfid);
 678                 goto clunk_olddir;
 679         }
 680
 681         /* 9P can only handle file rename in the same directory */
 682         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 683                 P9_DPRINTK(P9_DEBUG_ERROR,
 684                                 "old dir and new dir are different\n");
 685                 retval = -EXDEV;
 686                 goto clunk_newdir;
 687         }
 688
 689         v9fs_blank_wstat(&wstat);
 690         wstat.muid = v9ses->uname;
 691         wstat.name = (char *) new_dentry->d_name.name;
 692         retval = p9_client_wstat(oldfid, &wstat);
 693
 694 clunk_newdir:
 695         p9_client_clunk(newdirfid);
 696
 697 clunk_olddir:
 698         p9_client_clunk(olddirfid);
 699
 700 done:
 701         return retval;
 702 }
 703
 704 /**
 705  * v9fs_vfs_getattr - retrieve file metadata
 706  * @mnt - mount information
 707  * @dentry - file to get attributes on
 708  * @stat - metadata structure to populate
 709  *
 710  */
 711
 712 static int
 713 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 714                  struct kstat *stat)
 715 {
 716         int err;
 717         struct v9fs_session_info *v9ses;
 718         struct p9_fid *fid;
 719         struct p9_stat *st;
 720
 721         P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry);
 722         err = -EPERM;
 723         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 724         if (v9ses->cache == CACHE_LOOSE)
 725                 return simple_getattr(mnt, dentry, stat);
 726
 727         fid = v9fs_fid_lookup(dentry);
 728         if (IS_ERR(fid))
 729                 return PTR_ERR(fid);
 730
 731         st = p9_client_stat(fid);
 732         if (IS_ERR(st))
 733                 return PTR_ERR(st);
 734
 735         v9fs_stat2inode(st, dentry->d_inode, dentry->d_inode->i_sb);
 736                 generic_fillattr(dentry->d_inode, stat);
 737
 738         kfree(st);
 739         return 0;
 740 }
 741
 742 /**
 743  * v9fs_vfs_setattr - set file metadata
 744  * @dentry: file whose metadata to set
 745  * @iattr: metadata assignment structure
 746  *
 747  */
 748
 749 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 750 {
 751         int retval;
 752         struct v9fs_session_info *v9ses;
 753         struct p9_fid *fid;
 754         struct p9_wstat wstat;
 755
 756         P9_DPRINTK(P9_DEBUG_VFS, "\n");
 757         retval = -EPERM;
 758         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 759         fid = v9fs_fid_lookup(dentry);
 760         if(IS_ERR(fid))
 761                 return PTR_ERR(fid);
 762
 763         v9fs_blank_wstat(&wstat);
 764         if (iattr->ia_valid & ATTR_MODE)
 765                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 766
 767         if (iattr->ia_valid & ATTR_MTIME)
 768                 wstat.mtime = iattr->ia_mtime.tv_sec;
 769
 770         if (iattr->ia_valid & ATTR_ATIME)
 771                 wstat.atime = iattr->ia_atime.tv_sec;
 772
 773         if (iattr->ia_valid & ATTR_SIZE)
 774                 wstat.length = iattr->ia_size;
 775
 776         if (v9fs_extended(v9ses)) {
 777                 if (iattr->ia_valid & ATTR_UID)
 778                         wstat.n_uid = iattr->ia_uid;
 779
 780                 if (iattr->ia_valid & ATTR_GID)
 781                         wstat.n_gid = iattr->ia_gid;
 782         }
 783
 784         retval = p9_client_wstat(fid, &wstat);
 785         if (retval >= 0)
 786                 retval = inode_setattr(dentry->d_inode, iattr);
 787
 788         return retval;
 789 }
 790
 791 /**
 792  * v9fs_stat2inode - populate an inode structure with mistat info
 793  * @stat: Plan 9 metadata (mistat) structure
 794  * @inode: inode to populate
 795  * @sb: superblock of filesystem
 796  *
 797  */
 798
 799 void
 800 v9fs_stat2inode(struct p9_stat *stat, struct inode *inode,
 801         struct super_block *sb)
 802 {
 803         int n;
 804         char ext[32];
 805         struct v9fs_session_info *v9ses = sb->s_fs_info;
 806
 807         inode->i_nlink = 1;
 808
 809         inode->i_atime.tv_sec = stat->atime;
 810         inode->i_mtime.tv_sec = stat->mtime;
 811         inode->i_ctime.tv_sec = stat->mtime;
 812
 813         inode->i_uid = v9ses->dfltuid;
 814         inode->i_gid = v9ses->dfltgid;
 815
 816         if (v9fs_extended(v9ses)) {
 817                 inode->i_uid = stat->n_uid;
 818                 inode->i_gid = stat->n_gid;
 819         }
 820
 821         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 822         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 823                 char type = 0;
 824                 int major = -1;
 825                 int minor = -1;
 826
 827                 n = stat->extension.len;
 828                 if (n > sizeof(ext)-1)
 829                         n = sizeof(ext)-1;
 830                 memmove(ext, stat->extension.str, n);
 831                 ext[n] = 0;
 832                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 833                 switch (type) {
 834                 case 'c':
 835                         inode->i_mode &= ~S_IFBLK;
 836                         inode->i_mode |= S_IFCHR;
 837                         break;
 838                 case 'b':
 839                         break;
 840                 default:
 841                         P9_DPRINTK(P9_DEBUG_ERROR,
 842                                 "Unknown special type %c (%.*s)\n", type,
 843                                 stat->extension.len, stat->extension.str);
 844                 };
 845                 inode->i_rdev = MKDEV(major, minor);
 846         } else
 847                 inode->i_rdev = 0;
 848
 849         inode->i_size = stat->length;
 850
 851         /* not real number of blocks, but 512 byte ones ... */
 852         inode->i_blocks = (inode->i_size + 512 - 1) >> 9;
 853 }
 854
 855 /**
 856  * v9fs_qid2ino - convert qid into inode number
 857  * @qid: qid to hash
 858  *
 859  * BUG: potential for inode number collisions?
 860  */
 861
 862 ino_t v9fs_qid2ino(struct p9_qid *qid)
 863 {
 864         u64 path = qid->path + 2;
 865         ino_t i = 0;
 866
 867         if (sizeof(ino_t) == sizeof(path))
 868                 memcpy(&i, &path, sizeof(ino_t));
 869         else
 870                 i = (ino_t) (path ^ (path >> 32));
 871
 872         return i;
 873 }
 874
 875 /**
 876  * v9fs_readlink - read a symlink's location (internal version)
 877  * @dentry: dentry for symlink
 878  * @buffer: buffer to load symlink location into
 879  * @buflen: length of buffer
 880  *
 881  */
 882
 883 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 884 {
 885         int retval;
 886
 887         struct v9fs_session_info *v9ses;
 888         struct p9_fid *fid;
 889         struct p9_stat *st;
 890
 891         P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name);
 892         retval = -EPERM;
 893         v9ses = v9fs_inode2v9ses(dentry->d_inode);
 894         fid = v9fs_fid_lookup(dentry);
 895         if (IS_ERR(fid))
 896                 return PTR_ERR(fid);
 897
 898         if (!v9fs_extended(v9ses))
 899                 return -EBADF;
 900
 901         st = p9_client_stat(fid);
 902         if (IS_ERR(st))
 903                 return PTR_ERR(st);
 904
 905         if (!(st->mode & P9_DMSYMLINK)) {
 906                 retval = -EINVAL;
 907                 goto done;
 908         }
 909
 910         /* copy extension buffer into buffer */
 911         if (st->extension.len < buflen)
 912                 buflen = st->extension.len + 1;
 913
 914         memmove(buffer, st->extension.str, buflen - 1);
 915         buffer[buflen-1] = 0;
 916
 917         P9_DPRINTK(P9_DEBUG_VFS,
 918                 "%s -> %.*s (%s)\n", dentry->d_name.name, st->extension.len,
 919                 st->extension.str, buffer);
 920
 921         retval = buflen;
 922
 923 done:
 924         kfree(st);
 925         return retval;
 926 }
 927
 928 /**
 929  * v9fs_vfs_readlink - read a symlink's location
 930  * @dentry: dentry for symlink
 931  * @buf: buffer to load symlink location into
 932  * @buflen: length of buffer
 933  *
 934  */
 935
 936 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
 937                              int buflen)
 938 {
 939         int retval;
 940         int ret;
 941         char *link = __getname();
 942
 943         if (unlikely(!link))
 944                 return -ENOMEM;
 945
 946         if (buflen > PATH_MAX)
 947                 buflen = PATH_MAX;
 948
 949         P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
 950
 951         retval = v9fs_readlink(dentry, link, buflen);
 952
 953         if (retval > 0) {
 954                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
 955                         P9_DPRINTK(P9_DEBUG_ERROR,
 956                                         "problem copying to user: %d\n", ret);
 957                         retval = ret;
 958                 }
 959         }
 960
 961         __putname(link);
 962         return retval;
 963 }
 964
 965 /**
 966  * v9fs_vfs_follow_link - follow a symlink path
 967  * @dentry: dentry for symlink
 968  * @nd: nameidata
 969  *
 970  */
 971
 972 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 973 {
 974         int len = 0;
 975         char *link = __getname();
 976
 977         P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name);
 978
 979         if (!link)
 980                 link = ERR_PTR(-ENOMEM);
 981         else {
 982                 len = v9fs_readlink(dentry, link, PATH_MAX);
 983
 984                 if (len < 0) {
 985                         __putname(link);
 986                         link = ERR_PTR(len);
 987                 } else
 988                         link[len] = 0;
 989         }
 990         nd_set_link(nd, link);
 991
 992         return NULL;
 993 }
 994
 995 /**
 996  * v9fs_vfs_put_link - release a symlink path
 997  * @dentry: dentry for symlink
 998  * @nd: nameidata
 999  *
1000  */
1001
1002 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1003 {
1004         char *s = nd_get_link(nd);
1005
1006         P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1007         if (!IS_ERR(s))
1008                 __putname(s);
1009 }
1010
1011 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1012         int mode, const char *extension)
1013 {
1014         u32 perm;
1015         struct v9fs_session_info *v9ses;
1016         struct p9_fid *fid;
1017
1018         v9ses = v9fs_inode2v9ses(dir);
1019         if (!v9fs_extended(v9ses)) {
1020                 P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n");
1021                 return -EPERM;
1022         }
1023
1024         perm = unixmode2p9mode(v9ses, mode);
1025         fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm,
1026                                                                 P9_OREAD);
1027         if (IS_ERR(fid))
1028                 return PTR_ERR(fid);
1029
1030         p9_client_clunk(fid);
1031         return 0;
1032 }
1033
1034 /**
1035  * v9fs_vfs_symlink - helper function to create symlinks
1036  * @dir: directory inode containing symlink
1037  * @dentry: dentry for symlink
1038  * @symname: symlink data
1039  *
1040  * See 9P2000.u RFC for more information
1041  *
1042  */
1043
1044 static int
1045 v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
1046 {
1047         P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino,
1048                                         dentry->d_name.name, symname);
1049
1050         return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname);
1051 }
1052
1053 /**
1054  * v9fs_vfs_link - create a hardlink
1055  * @old_dentry: dentry for file to link to
1056  * @dir: inode destination for new link
1057  * @dentry: dentry for link
1058  *
1059  */
1060
1061 /* XXX - lots of code dup'd from symlink and creates,
1062  * figure out a better reuse strategy
1063  */
1064
1065 static int
1066 v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir,
1067               struct dentry *dentry)
1068 {
1069         int retval;
1070         struct p9_fid *oldfid;
1071         char *name;
1072
1073         P9_DPRINTK(P9_DEBUG_VFS,
1074                 " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name,
1075                 old_dentry->d_name.name);
1076
1077         oldfid = v9fs_fid_clone(old_dentry);
1078         if (IS_ERR(oldfid))
1079                 return PTR_ERR(oldfid);
1080
1081         name = __getname();
1082         if (unlikely(!name)) {
1083                 retval = -ENOMEM;
1084                 goto clunk_fid;
1085         }
1086
1087         sprintf(name, "%d\n", oldfid->fid);
1088         retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name);
1089         __putname(name);
1090
1091 clunk_fid:
1092         p9_client_clunk(oldfid);
1093         return retval;
1094 }
1095
1096 /**
1097  * v9fs_vfs_mknod - create a special file
1098  * @dir: inode destination for new link
1099  * @dentry: dentry for file
1100  * @mode: mode for creation
1101  * @dev_t: device associated with special file
1102  *
1103  */
1104
1105 static int
1106 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1107 {
1108         int retval;
1109         char *name;
1110
1111         P9_DPRINTK(P9_DEBUG_VFS,
1112                 " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1113                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1114
1115         if (!new_valid_dev(rdev))
1116                 return -EINVAL;
1117
1118         name = __getname();
1119         if (!name)
1120                 return -ENOMEM;
1121         /* build extension */
1122         if (S_ISBLK(mode))
1123                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1124         else if (S_ISCHR(mode))
1125                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1126         else if (S_ISFIFO(mode))
1127                 *name = 0;
1128         else {
1129                 __putname(name);
1130                 return -EINVAL;
1131         }
1132
1133         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1134         __putname(name);
1135
1136         return retval;
1137 }
1138
1139 static const struct inode_operations v9fs_dir_inode_operations_ext = {
1140         .create = v9fs_vfs_create,
1141         .lookup = v9fs_vfs_lookup,
1142         .symlink = v9fs_vfs_symlink,
1143         .link = v9fs_vfs_link,
1144         .unlink = v9fs_vfs_unlink,
1145         .mkdir = v9fs_vfs_mkdir,
1146         .rmdir = v9fs_vfs_rmdir,
1147         .mknod = v9fs_vfs_mknod,
1148         .rename = v9fs_vfs_rename,
1149         .readlink = v9fs_vfs_readlink,
1150         .getattr = v9fs_vfs_getattr,
1151         .setattr = v9fs_vfs_setattr,
1152 };
1153
1154 static const struct inode_operations v9fs_dir_inode_operations = {
1155         .create = v9fs_vfs_create,
1156         .lookup = v9fs_vfs_lookup,
1157         .unlink = v9fs_vfs_unlink,
1158         .mkdir = v9fs_vfs_mkdir,
1159         .rmdir = v9fs_vfs_rmdir,
1160         .mknod = v9fs_vfs_mknod,
1161         .rename = v9fs_vfs_rename,
1162         .getattr = v9fs_vfs_getattr,
1163         .setattr = v9fs_vfs_setattr,
1164 };
1165
1166 static const struct inode_operations v9fs_file_inode_operations = {
1167         .getattr = v9fs_vfs_getattr,
1168         .setattr = v9fs_vfs_setattr,
1169 };
1170
1171 static const struct inode_operations v9fs_symlink_inode_operations = {
1172         .readlink = v9fs_vfs_readlink,
1173         .follow_link = v9fs_vfs_follow_link,
1174         .put_link = v9fs_vfs_put_link,
1175         .getattr = v9fs_vfs_getattr,
1176         .setattr = v9fs_vfs_setattr,
1177 };