fs/9p/vfs_inode.c

   1 /*
   2  *  linux/fs/9p/vfs_inode.c
   3  *
   4  * This file contains vfs inode ops for the 9P2000 protocol.
   5  *
   6  *  Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com>
   7  *  Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License version 2
  11  *  as published by the Free Software Foundation.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to:
  20  *  Free Software Foundation
  21  *  51 Franklin Street, Fifth Floor
  22  *  Boston, MA  02111-1301  USA
  23  *
  24  */
  25
  26 #include <linux/module.h>
  27 #include <linux/errno.h>
  28 #include <linux/fs.h>
  29 #include <linux/file.h>
  30 #include <linux/pagemap.h>
  31 #include <linux/stat.h>
  32 #include <linux/string.h>
  33 #include <linux/smp_lock.h>
  34 #include <linux/inet.h>
  35 #include <linux/namei.h>
  36 #include <linux/idr.h>
  37
  38 #include "debug.h"
  39 #include "v9fs.h"
  40 #include "9p.h"
  41 #include "v9fs_vfs.h"
  42 #include "fid.h"
  43
  44 static struct inode_operations v9fs_dir_inode_operations;
  45 static struct inode_operations v9fs_dir_inode_operations_ext;
  46 static struct inode_operations v9fs_file_inode_operations;
  47 static struct inode_operations v9fs_symlink_inode_operations;
  48
  49 /**
  50  * unixmode2p9mode - convert unix mode bits to plan 9
  51  * @v9ses: v9fs session information
  52  * @mode: mode to convert
  53  *
  54  */
  55
  56 static int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode)
  57 {
  58         int res;
  59         res = mode & 0777;
  60         if (S_ISDIR(mode))
  61                 res |= V9FS_DMDIR;
  62         if (v9ses->extended) {
  63                 if (S_ISLNK(mode))
  64                         res |= V9FS_DMSYMLINK;
  65                 if (v9ses->nodev == 0) {
  66                         if (S_ISSOCK(mode))
  67                                 res |= V9FS_DMSOCKET;
  68                         if (S_ISFIFO(mode))
  69                                 res |= V9FS_DMNAMEDPIPE;
  70                         if (S_ISBLK(mode))
  71                                 res |= V9FS_DMDEVICE;
  72                         if (S_ISCHR(mode))
  73                                 res |= V9FS_DMDEVICE;
  74                 }
  75
  76                 if ((mode & S_ISUID) == S_ISUID)
  77                         res |= V9FS_DMSETUID;
  78                 if ((mode & S_ISGID) == S_ISGID)
  79                         res |= V9FS_DMSETGID;
  80                 if ((mode & V9FS_DMLINK))
  81                         res |= V9FS_DMLINK;
  82         }
  83
  84         return res;
  85 }
  86
  87 /**
  88  * p9mode2unixmode- convert plan9 mode bits to unix mode bits
  89  * @v9ses: v9fs session information
  90  * @mode: mode to convert
  91  *
  92  */
  93
  94 static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode)
  95 {
  96         int res;
  97
  98         res = mode & 0777;
  99
 100         if ((mode & V9FS_DMDIR) == V9FS_DMDIR)
 101                 res |= S_IFDIR;
 102         else if ((mode & V9FS_DMSYMLINK) && (v9ses->extended))
 103                 res |= S_IFLNK;
 104         else if ((mode & V9FS_DMSOCKET) && (v9ses->extended)
 105                  && (v9ses->nodev == 0))
 106                 res |= S_IFSOCK;
 107         else if ((mode & V9FS_DMNAMEDPIPE) && (v9ses->extended)
 108                  && (v9ses->nodev == 0))
 109                 res |= S_IFIFO;
 110         else if ((mode & V9FS_DMDEVICE) && (v9ses->extended)
 111                  && (v9ses->nodev == 0))
 112                 res |= S_IFBLK;
 113         else
 114                 res |= S_IFREG;
 115
 116         if (v9ses->extended) {
 117                 if ((mode & V9FS_DMSETUID) == V9FS_DMSETUID)
 118                         res |= S_ISUID;
 119
 120                 if ((mode & V9FS_DMSETGID) == V9FS_DMSETGID)
 121                         res |= S_ISGID;
 122         }
 123
 124         return res;
 125 }
 126
 127 int v9fs_uflags2omode(int uflags)
 128 {
 129         int ret;
 130
 131         ret = 0;
 132         switch (uflags&3) {
 133         default:
 134         case O_RDONLY:
 135                 ret = V9FS_OREAD;
 136                 break;
 137
 138         case O_WRONLY:
 139                 ret = V9FS_OWRITE;
 140                 break;
 141
 142         case O_RDWR:
 143                 ret = V9FS_ORDWR;
 144                 break;
 145         }
 146
 147         if (uflags & O_EXCL)
 148                 ret |= V9FS_OEXCL;
 149
 150         if (uflags & O_TRUNC)
 151                 ret |= V9FS_OTRUNC;
 152
 153         if (uflags & O_APPEND)
 154                 ret |= V9FS_OAPPEND;
 155
 156         return ret;
 157 }
 158
 159 /**
 160  * v9fs_blank_wstat - helper function to setup a 9P stat structure
 161  * @v9ses: 9P session info (for determining extended mode)
 162  * @wstat: structure to initialize
 163  *
 164  */
 165
 166 static void
 167 v9fs_blank_wstat(struct v9fs_wstat *wstat)
 168 {
 169         wstat->type = ~0;
 170         wstat->dev = ~0;
 171         wstat->qid.type = ~0;
 172         wstat->qid.version = ~0;
 173         *((long long *)&wstat->qid.path) = ~0;
 174         wstat->mode = ~0;
 175         wstat->atime = ~0;
 176         wstat->mtime = ~0;
 177         wstat->length = ~0;
 178         wstat->name = NULL;
 179         wstat->uid = NULL;
 180         wstat->gid = NULL;
 181         wstat->muid = NULL;
 182         wstat->n_uid = ~0;
 183         wstat->n_gid = ~0;
 184         wstat->n_muid = ~0;
 185         wstat->extension = NULL;
 186 }
 187
 188 /**
 189  * v9fs_get_inode - helper function to setup an inode
 190  * @sb: superblock
 191  * @mode: mode to setup inode with
 192  *
 193  */
 194
 195 struct inode *v9fs_get_inode(struct super_block *sb, int mode)
 196 {
 197         struct inode *inode;
 198         struct v9fs_session_info *v9ses = sb->s_fs_info;
 199
 200         dprintk(DEBUG_VFS, "super block: %p mode: %o\n", sb, mode);
 201
 202         inode = new_inode(sb);
 203         if (inode) {
 204                 inode->i_mode = mode;
 205                 inode->i_uid = current->fsuid;
 206                 inode->i_gid = current->fsgid;
 207                 inode->i_blksize = sb->s_blocksize;
 208                 inode->i_blocks = 0;
 209                 inode->i_rdev = 0;
 210                 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 211                 inode->i_mapping->a_ops = &v9fs_addr_operations;
 212
 213                 switch (mode & S_IFMT) {
 214                 case S_IFIFO:
 215                 case S_IFBLK:
 216                 case S_IFCHR:
 217                 case S_IFSOCK:
 218                         if(!v9ses->extended) {
 219                                 dprintk(DEBUG_ERROR, "special files without extended mode\n");
 220                                 return ERR_PTR(-EINVAL);
 221                         }
 222                         init_special_inode(inode, inode->i_mode,
 223                                            inode->i_rdev);
 224                         break;
 225                 case S_IFREG:
 226                         inode->i_op = &v9fs_file_inode_operations;
 227                         inode->i_fop = &v9fs_file_operations;
 228                         break;
 229                 case S_IFLNK:
 230                         if(!v9ses->extended) {
 231                                 dprintk(DEBUG_ERROR, "extended modes used w/o 9P2000.u\n");
 232                                 return ERR_PTR(-EINVAL);
 233                         }
 234                         inode->i_op = &v9fs_symlink_inode_operations;
 235                         break;
 236                 case S_IFDIR:
 237                         inode->i_nlink++;
 238                         if(v9ses->extended)
 239                                 inode->i_op = &v9fs_dir_inode_operations_ext;
 240                         else
 241                                 inode->i_op = &v9fs_dir_inode_operations;
 242                         inode->i_fop = &v9fs_dir_operations;
 243                         break;
 244                 default:
 245                         dprintk(DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n",
 246                                 mode, mode & S_IFMT);
 247                         return ERR_PTR(-EINVAL);
 248                 }
 249         } else {
 250                 eprintk(KERN_WARNING, "Problem allocating inode\n");
 251                 return ERR_PTR(-ENOMEM);
 252         }
 253         return inode;
 254 }
 255
 256 static int
 257 v9fs_create(struct v9fs_session_info *v9ses, u32 pfid, char *name, u32 perm,
 258         u8 mode, char *extension, u32 *fidp, struct v9fs_qid *qid, u32 *iounit)
 259 {
 260         u32 fid;
 261         int err;
 262         struct v9fs_fcall *fcall;
 263
 264         fid = v9fs_get_idpool(&v9ses->fidpool);
 265         if (fid < 0) {
 266                 eprintk(KERN_WARNING, "no free fids available\n");
 267                 return -ENOSPC;
 268         }
 269
 270         err = v9fs_t_walk(v9ses, pfid, fid, NULL, &fcall);
 271         if (err < 0) {
 272                 PRINT_FCALL_ERROR("clone error", fcall);
 273                 if (fcall && fcall->id == RWALK)
 274                         goto clunk_fid;
 275                 else
 276                         goto put_fid;
 277         }
 278         kfree(fcall);
 279
 280         err = v9fs_t_create(v9ses, fid, name, perm, mode, extension, &fcall);
 281         if (err < 0) {
 282                 PRINT_FCALL_ERROR("create fails", fcall);
 283                 goto clunk_fid;
 284         }
 285
 286         if (iounit)
 287                 *iounit = fcall->params.rcreate.iounit;
 288
 289         if (qid)
 290                 *qid = fcall->params.rcreate.qid;
 291
 292         if (fidp)
 293                 *fidp = fid;
 294
 295         kfree(fcall);
 296         return 0;
 297
 298 clunk_fid:
 299         v9fs_t_clunk(v9ses, fid);
 300         fid = V9FS_NOFID;
 301
 302 put_fid:
 303         if (fid != V9FS_NOFID)
 304                 v9fs_put_idpool(fid, &v9ses->fidpool);
 305
 306         kfree(fcall);
 307         return err;
 308 }
 309
 310 static struct v9fs_fid*
 311 v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry)
 312 {
 313         int err;
 314         u32 nfid;
 315         struct v9fs_fid *ret;
 316         struct v9fs_fcall *fcall;
 317
 318         nfid = v9fs_get_idpool(&v9ses->fidpool);
 319         if (nfid < 0) {
 320                 eprintk(KERN_WARNING, "no free fids available\n");
 321                 return ERR_PTR(-ENOSPC);
 322         }
 323
 324         err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name,
 325                 &fcall);
 326
 327         if (err < 0) {
 328                 if (fcall && fcall->id == RWALK)
 329                         goto clunk_fid;
 330
 331                 PRINT_FCALL_ERROR("walk error", fcall);
 332                 v9fs_put_idpool(nfid, &v9ses->fidpool);
 333                 goto error;
 334         }
 335
 336         kfree(fcall);
 337         fcall = NULL;
 338         ret = v9fs_fid_create(v9ses, nfid);
 339         if (!ret) {
 340                 err = -ENOMEM;
 341                 goto clunk_fid;
 342         }
 343
 344         err = v9fs_fid_insert(ret, dentry);
 345         if (err < 0) {
 346                 v9fs_fid_destroy(ret);
 347                 goto clunk_fid;
 348         }
 349
 350         return ret;
 351
 352 clunk_fid:
 353         v9fs_t_clunk(v9ses, nfid);
 354
 355 error:
 356         kfree(fcall);
 357         return ERR_PTR(err);
 358 }
 359
 360 static struct inode *
 361 v9fs_inode_from_fid(struct v9fs_session_info *v9ses, u32 fid,
 362         struct super_block *sb)
 363 {
 364         int err, umode;
 365         struct inode *ret;
 366         struct v9fs_fcall *fcall;
 367
 368         ret = NULL;
 369         err = v9fs_t_stat(v9ses, fid, &fcall);
 370         if (err) {
 371                 PRINT_FCALL_ERROR("stat error", fcall);
 372                 goto error;
 373         }
 374
 375         umode = p9mode2unixmode(v9ses, fcall->params.rstat.stat.mode);
 376         ret = v9fs_get_inode(sb, umode);
 377         if (IS_ERR(ret)) {
 378                 err = PTR_ERR(ret);
 379                 ret = NULL;
 380                 goto error;
 381         }
 382
 383         v9fs_stat2inode(&fcall->params.rstat.stat, ret, sb);
 384         kfree(fcall);
 385         return ret;
 386
 387 error:
 388         kfree(fcall);
 389         if (ret)
 390                 iput(ret);
 391
 392         return ERR_PTR(err);
 393 }
 394
 395 /**
 396  * v9fs_remove - helper function to remove files and directories
 397  * @dir: directory inode that is being deleted
 398  * @file:  dentry that is being deleted
 399  * @rmdir: removing a directory
 400  *
 401  */
 402
 403 static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir)
 404 {
 405         struct v9fs_fcall *fcall = NULL;
 406         struct super_block *sb = NULL;
 407         struct v9fs_session_info *v9ses = NULL;
 408         struct v9fs_fid *v9fid = NULL;
 409         struct inode *file_inode = NULL;
 410         int fid = -1;
 411         int result = 0;
 412
 413         dprintk(DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file,
 414                 rmdir);
 415
 416         file_inode = file->d_inode;
 417         sb = file_inode->i_sb;
 418         v9ses = v9fs_inode2v9ses(file_inode);
 419         v9fid = v9fs_fid_lookup(file);
 420
 421         if (!v9fid) {
 422                 dprintk(DEBUG_ERROR,
 423                         "no v9fs_fid\n");
 424                 return -EBADF;
 425         }
 426
 427         fid = v9fid->fid;
 428         if (fid < 0) {
 429                 dprintk(DEBUG_ERROR, "inode #%lu, no fid!\n",
 430                         file_inode->i_ino);
 431                 return -EBADF;
 432         }
 433
 434         result = v9fs_t_remove(v9ses, fid, &fcall);
 435         if (result < 0) {
 436                 PRINT_FCALL_ERROR("remove fails", fcall);
 437         }
 438
 439         v9fs_put_idpool(fid, &v9ses->fidpool);
 440         v9fs_fid_destroy(v9fid);
 441
 442         kfree(fcall);
 443         return result;
 444 }
 445
 446 static int
 447 v9fs_open_created(struct inode *inode, struct file *file)
 448 {
 449         return 0;
 450 }
 451
 452 /**
 453  * v9fs_vfs_create - VFS hook to create files
 454  * @inode: directory inode that is being deleted
 455  * @dentry:  dentry that is being deleted
 456  * @mode: create permissions
 457  * @nd: path information
 458  *
 459  */
 460
 461 static int
 462 v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode,
 463                 struct nameidata *nd)
 464 {
 465         int err;
 466         u32 fid, perm, iounit;
 467         int flags;
 468         struct v9fs_session_info *v9ses;
 469         struct v9fs_fid *dfid, *vfid, *ffid;
 470         struct inode *inode;
 471         struct v9fs_qid qid;
 472         struct file *filp;
 473
 474         inode = NULL;
 475         vfid = NULL;
 476         v9ses = v9fs_inode2v9ses(dir);
 477         dfid = v9fs_fid_lookup(dentry->d_parent);
 478         perm = unixmode2p9mode(v9ses, mode);
 479
 480         if (nd && nd->flags & LOOKUP_OPEN)
 481                 flags = nd->intent.open.flags - 1;
 482         else
 483                 flags = O_RDWR;
 484
 485         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 486                 perm, v9fs_uflags2omode(flags), NULL, &fid, &qid, &iounit);
 487
 488         if (err)
 489                 goto error;
 490
 491         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 492         if (IS_ERR(vfid)) {
 493                 err = PTR_ERR(vfid);
 494                 vfid = NULL;
 495                 goto error;
 496         }
 497
 498         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 499         if (IS_ERR(inode)) {
 500                 err = PTR_ERR(inode);
 501                 inode = NULL;
 502                 goto error;
 503         }
 504
 505         dentry->d_op = &v9fs_dentry_operations;
 506         d_instantiate(dentry, inode);
 507
 508         if (nd && nd->flags & LOOKUP_OPEN) {
 509                 ffid = v9fs_fid_create(v9ses, fid);
 510                 if (!ffid)
 511                         return -ENOMEM;
 512
 513                 filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created);
 514                 if (IS_ERR(filp)) {
 515                         v9fs_fid_destroy(ffid);
 516                         return PTR_ERR(filp);
 517                 }
 518
 519                 ffid->rdir_pos = 0;
 520                 ffid->rdir_fcall = NULL;
 521                 ffid->fidopen = 1;
 522                 ffid->iounit = iounit;
 523                 ffid->filp = filp;
 524                 filp->private_data = ffid;
 525         }
 526
 527         return 0;
 528
 529 error:
 530         if (vfid)
 531                 v9fs_fid_destroy(vfid);
 532
 533         return err;
 534 }
 535
 536 /**
 537  * v9fs_vfs_mkdir - VFS mkdir hook to create a directory
 538  * @inode:  inode that is being unlinked
 539  * @dentry: dentry that is being unlinked
 540  * @mode: mode for new directory
 541  *
 542  */
 543
 544 static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
 545 {
 546         int err;
 547         u32 fid, perm;
 548         struct v9fs_session_info *v9ses;
 549         struct v9fs_fid *dfid, *vfid;
 550         struct inode *inode;
 551
 552         inode = NULL;
 553         vfid = NULL;
 554         v9ses = v9fs_inode2v9ses(dir);
 555         dfid = v9fs_fid_lookup(dentry->d_parent);
 556         perm = unixmode2p9mode(v9ses, mode | S_IFDIR);
 557
 558         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
 559                 perm, V9FS_OREAD, NULL, &fid, NULL, NULL);
 560
 561         if (err) {
 562                 dprintk(DEBUG_ERROR, "create error %d\n", err);
 563                 goto error;
 564         }
 565
 566         err = v9fs_t_clunk(v9ses, fid);
 567         if (err) {
 568                 dprintk(DEBUG_ERROR, "clunk error %d\n", err);
 569                 goto error;
 570         }
 571
 572         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
 573         if (IS_ERR(vfid)) {
 574                 err = PTR_ERR(vfid);
 575                 vfid = NULL;
 576                 goto error;
 577         }
 578
 579         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
 580         if (IS_ERR(inode)) {
 581                 err = PTR_ERR(inode);
 582                 inode = NULL;
 583                 goto error;
 584         }
 585
 586         dentry->d_op = &v9fs_dentry_operations;
 587         d_instantiate(dentry, inode);
 588         return 0;
 589
 590 error:
 591         if (vfid)
 592                 v9fs_fid_destroy(vfid);
 593
 594         return err;
 595 }
 596
 597 /**
 598  * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode
 599  * @dir:  inode that is being walked from
 600  * @dentry: dentry that is being walked to?
 601  * @nameidata: path data
 602  *
 603  */
 604
 605 static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry,
 606                                       struct nameidata *nameidata)
 607 {
 608         struct super_block *sb;
 609         struct v9fs_session_info *v9ses;
 610         struct v9fs_fid *dirfid;
 611         struct v9fs_fid *fid;
 612         struct inode *inode;
 613         struct v9fs_fcall *fcall = NULL;
 614         int dirfidnum = -1;
 615         int newfid = -1;
 616         int result = 0;
 617
 618         dprintk(DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n",
 619                 dir, dentry->d_name.name, dentry, nameidata);
 620
 621         sb = dir->i_sb;
 622         v9ses = v9fs_inode2v9ses(dir);
 623         dentry->d_op = &v9fs_dentry_operations;
 624         dirfid = v9fs_fid_lookup(dentry->d_parent);
 625
 626         if (!dirfid) {
 627                 dprintk(DEBUG_ERROR, "no dirfid\n");
 628                 return ERR_PTR(-EINVAL);
 629         }
 630
 631         dirfidnum = dirfid->fid;
 632
 633         if (dirfidnum < 0) {
 634                 dprintk(DEBUG_ERROR, "no dirfid for inode %p, #%lu\n",
 635                         dir, dir->i_ino);
 636                 return ERR_PTR(-EBADF);
 637         }
 638
 639         newfid = v9fs_get_idpool(&v9ses->fidpool);
 640         if (newfid < 0) {
 641                 eprintk(KERN_WARNING, "newfid fails!\n");
 642                 return ERR_PTR(-ENOSPC);
 643         }
 644
 645         result = v9fs_t_walk(v9ses, dirfidnum, newfid,
 646                 (char *)dentry->d_name.name, &fcall);
 647
 648         if (result < 0) {
 649                 if (fcall && fcall->id == RWALK)
 650                         v9fs_t_clunk(v9ses, newfid);
 651                 else
 652                         v9fs_put_idpool(newfid, &v9ses->fidpool);
 653
 654                 if (result == -ENOENT) {
 655                         d_add(dentry, NULL);
 656                         dprintk(DEBUG_VFS,
 657                                 "Return negative dentry %p count %d\n",
 658                                 dentry, atomic_read(&dentry->d_count));
 659                         kfree(fcall);
 660                         return NULL;
 661                 }
 662                 dprintk(DEBUG_ERROR, "walk error:%d\n", result);
 663                 goto FreeFcall;
 664         }
 665         kfree(fcall);
 666
 667         result = v9fs_t_stat(v9ses, newfid, &fcall);
 668         if (result < 0) {
 669                 dprintk(DEBUG_ERROR, "stat error\n");
 670                 goto FreeFcall;
 671         }
 672
 673         inode = v9fs_get_inode(sb, p9mode2unixmode(v9ses,
 674                 fcall->params.rstat.stat.mode));
 675
 676         if (IS_ERR(inode) && (PTR_ERR(inode) == -ENOSPC)) {
 677                 eprintk(KERN_WARNING, "inode alloc failes, returns %ld\n",
 678                         PTR_ERR(inode));
 679
 680                 result = -ENOSPC;
 681                 goto FreeFcall;
 682         }
 683
 684         inode->i_ino = v9fs_qid2ino(&fcall->params.rstat.stat.qid);
 685
 686         fid = v9fs_fid_create(v9ses, newfid);
 687         if (fid == NULL) {
 688                 dprintk(DEBUG_ERROR, "couldn't insert\n");
 689                 result = -ENOMEM;
 690                 goto FreeFcall;
 691         }
 692
 693         result = v9fs_fid_insert(fid, dentry);
 694         if (result < 0)
 695                 goto FreeFcall;
 696
 697         fid->qid = fcall->params.rstat.stat.qid;
 698         v9fs_stat2inode(&fcall->params.rstat.stat, inode, inode->i_sb);
 699
 700         d_add(dentry, inode);
 701         kfree(fcall);
 702
 703         return NULL;
 704
 705       FreeFcall:
 706         kfree(fcall);
 707         return ERR_PTR(result);
 708 }
 709
 710 /**
 711  * v9fs_vfs_unlink - VFS unlink hook to delete an inode
 712  * @i:  inode that is being unlinked
 713  * @d: dentry that is being unlinked
 714  *
 715  */
 716
 717 static int v9fs_vfs_unlink(struct inode *i, struct dentry *d)
 718 {
 719         return v9fs_remove(i, d, 0);
 720 }
 721
 722 /**
 723  * v9fs_vfs_rmdir - VFS unlink hook to delete a directory
 724  * @i:  inode that is being unlinked
 725  * @d: dentry that is being unlinked
 726  *
 727  */
 728
 729 static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d)
 730 {
 731         return v9fs_remove(i, d, 1);
 732 }
 733
 734 /**
 735  * v9fs_vfs_rename - VFS hook to rename an inode
 736  * @old_dir:  old dir inode
 737  * @old_dentry: old dentry
 738  * @new_dir: new dir inode
 739  * @new_dentry: new dentry
 740  *
 741  */
 742
 743 static int
 744 v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry,
 745                 struct inode *new_dir, struct dentry *new_dentry)
 746 {
 747         struct inode *old_inode = old_dentry->d_inode;
 748         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(old_inode);
 749         struct v9fs_fid *oldfid = v9fs_fid_lookup(old_dentry);
 750         struct v9fs_fid *olddirfid =
 751             v9fs_fid_lookup(old_dentry->d_parent);
 752         struct v9fs_fid *newdirfid =
 753             v9fs_fid_lookup(new_dentry->d_parent);
 754         struct v9fs_wstat wstat;
 755         struct v9fs_fcall *fcall = NULL;
 756         int fid = -1;
 757         int olddirfidnum = -1;
 758         int newdirfidnum = -1;
 759         int retval = 0;
 760
 761         dprintk(DEBUG_VFS, "\n");
 762
 763         if ((!oldfid) || (!olddirfid) || (!newdirfid)) {
 764                 dprintk(DEBUG_ERROR, "problem with arguments\n");
 765                 return -EBADF;
 766         }
 767
 768         /* 9P can only handle file rename in the same directory */
 769         if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) {
 770                 dprintk(DEBUG_ERROR, "old dir and new dir are different\n");
 771                 retval = -EPERM;
 772                 goto FreeFcallnBail;
 773         }
 774
 775         fid = oldfid->fid;
 776         olddirfidnum = olddirfid->fid;
 777         newdirfidnum = newdirfid->fid;
 778
 779         if (fid < 0) {
 780                 dprintk(DEBUG_ERROR, "no fid for old file #%lu\n",
 781                         old_inode->i_ino);
 782                 retval = -EBADF;
 783                 goto FreeFcallnBail;
 784         }
 785
 786         v9fs_blank_wstat(&wstat);
 787         wstat.muid = v9ses->name;
 788         wstat.name = (char *) new_dentry->d_name.name;
 789
 790         retval = v9fs_t_wstat(v9ses, fid, &wstat, &fcall);
 791
 792       FreeFcallnBail:
 793         if (retval < 0)
 794                 PRINT_FCALL_ERROR("wstat error", fcall);
 795
 796         kfree(fcall);
 797         return retval;
 798 }
 799
 800 /**
 801  * v9fs_vfs_getattr - retrieve file metadata
 802  * @mnt - mount information
 803  * @dentry - file to get attributes on
 804  * @stat - metadata structure to populate
 805  *
 806  */
 807
 808 static int
 809 v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 810                  struct kstat *stat)
 811 {
 812         struct v9fs_fcall *fcall = NULL;
 813         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 814         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 815         int err = -EPERM;
 816
 817         dprintk(DEBUG_VFS, "dentry: %p\n", dentry);
 818         if (!fid) {
 819                 dprintk(DEBUG_ERROR,
 820                         "couldn't find fid associated with dentry\n");
 821                 return -EBADF;
 822         }
 823
 824         err = v9fs_t_stat(v9ses, fid->fid, &fcall);
 825
 826         if (err < 0)
 827                 dprintk(DEBUG_ERROR, "stat error\n");
 828         else {
 829                 v9fs_stat2inode(&fcall->params.rstat.stat, dentry->d_inode,
 830                                   dentry->d_inode->i_sb);
 831                 generic_fillattr(dentry->d_inode, stat);
 832         }
 833
 834         kfree(fcall);
 835         return err;
 836 }
 837
 838 /**
 839  * v9fs_vfs_setattr - set file metadata
 840  * @dentry: file whose metadata to set
 841  * @iattr: metadata assignment structure
 842  *
 843  */
 844
 845 static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr)
 846 {
 847         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 848         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 849         struct v9fs_fcall *fcall = NULL;
 850         struct v9fs_wstat wstat;
 851         int res = -EPERM;
 852
 853         dprintk(DEBUG_VFS, "\n");
 854
 855         if (!fid) {
 856                 dprintk(DEBUG_ERROR,
 857                         "Couldn't find fid associated with dentry\n");
 858                 return -EBADF;
 859         }
 860
 861         v9fs_blank_wstat(&wstat);
 862         if (iattr->ia_valid & ATTR_MODE)
 863                 wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode);
 864
 865         if (iattr->ia_valid & ATTR_MTIME)
 866                 wstat.mtime = iattr->ia_mtime.tv_sec;
 867
 868         if (iattr->ia_valid & ATTR_ATIME)
 869                 wstat.atime = iattr->ia_atime.tv_sec;
 870
 871         if (iattr->ia_valid & ATTR_SIZE)
 872                 wstat.length = iattr->ia_size;
 873
 874         if (v9ses->extended) {
 875                 if (iattr->ia_valid & ATTR_UID)
 876                         wstat.n_uid = iattr->ia_uid;
 877
 878                 if (iattr->ia_valid & ATTR_GID)
 879                         wstat.n_gid = iattr->ia_gid;
 880         }
 881
 882         res = v9fs_t_wstat(v9ses, fid->fid, &wstat, &fcall);
 883
 884         if (res < 0)
 885                 PRINT_FCALL_ERROR("wstat error", fcall);
 886
 887         kfree(fcall);
 888         if (res >= 0)
 889                 res = inode_setattr(dentry->d_inode, iattr);
 890
 891         return res;
 892 }
 893
 894 /**
 895  * v9fs_stat2inode - populate an inode structure with mistat info
 896  * @stat: Plan 9 metadata (mistat) structure
 897  * @inode: inode to populate
 898  * @sb: superblock of filesystem
 899  *
 900  */
 901
 902 void
 903 v9fs_stat2inode(struct v9fs_stat *stat, struct inode *inode,
 904         struct super_block *sb)
 905 {
 906         int n;
 907         char ext[32];
 908         struct v9fs_session_info *v9ses = sb->s_fs_info;
 909
 910         inode->i_nlink = 1;
 911
 912         inode->i_atime.tv_sec = stat->atime;
 913         inode->i_mtime.tv_sec = stat->mtime;
 914         inode->i_ctime.tv_sec = stat->mtime;
 915
 916         inode->i_uid = v9ses->uid;
 917         inode->i_gid = v9ses->gid;
 918
 919         if (v9ses->extended) {
 920                 inode->i_uid = stat->n_uid;
 921                 inode->i_gid = stat->n_gid;
 922         }
 923
 924         inode->i_mode = p9mode2unixmode(v9ses, stat->mode);
 925         if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) {
 926                 char type = 0;
 927                 int major = -1;
 928                 int minor = -1;
 929
 930                 n = stat->extension.len;
 931                 if (n > sizeof(ext)-1)
 932                         n = sizeof(ext)-1;
 933                 memmove(ext, stat->extension.str, n);
 934                 ext[n] = 0;
 935                 sscanf(ext, "%c %u %u", &type, &major, &minor);
 936                 switch (type) {
 937                 case 'c':
 938                         inode->i_mode &= ~S_IFBLK;
 939                         inode->i_mode |= S_IFCHR;
 940                         break;
 941                 case 'b':
 942                         break;
 943                 default:
 944                         dprintk(DEBUG_ERROR, "Unknown special type %c (%.*s)\n",
 945                                 type, stat->extension.len, stat->extension.str);
 946                 };
 947                 inode->i_rdev = MKDEV(major, minor);
 948         } else
 949                 inode->i_rdev = 0;
 950
 951         inode->i_size = stat->length;
 952
 953         inode->i_blksize = sb->s_blocksize;
 954         inode->i_blocks =
 955             (inode->i_size + inode->i_blksize - 1) >> sb->s_blocksize_bits;
 956 }
 957
 958 /**
 959  * v9fs_qid2ino - convert qid into inode number
 960  * @qid: qid to hash
 961  *
 962  * BUG: potential for inode number collisions?
 963  */
 964
 965 ino_t v9fs_qid2ino(struct v9fs_qid *qid)
 966 {
 967         u64 path = qid->path + 2;
 968         ino_t i = 0;
 969
 970         if (sizeof(ino_t) == sizeof(path))
 971                 memcpy(&i, &path, sizeof(ino_t));
 972         else
 973                 i = (ino_t) (path ^ (path >> 32));
 974
 975         return i;
 976 }
 977
 978 /**
 979  * v9fs_readlink - read a symlink's location (internal version)
 980  * @dentry: dentry for symlink
 981  * @buffer: buffer to load symlink location into
 982  * @buflen: length of buffer
 983  *
 984  */
 985
 986 static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen)
 987 {
 988         int retval = -EPERM;
 989
 990         struct v9fs_fcall *fcall = NULL;
 991         struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dentry->d_inode);
 992         struct v9fs_fid *fid = v9fs_fid_lookup(dentry);
 993
 994         if (!fid) {
 995                 dprintk(DEBUG_ERROR, "could not resolve fid from dentry\n");
 996                 retval = -EBADF;
 997                 goto FreeFcall;
 998         }
 999
1000         if (!v9ses->extended) {
1001                 retval = -EBADF;
1002                 dprintk(DEBUG_ERROR, "not extended\n");
1003                 goto FreeFcall;
1004         }
1005
1006         dprintk(DEBUG_VFS, " %s\n", dentry->d_name.name);
1007         retval = v9fs_t_stat(v9ses, fid->fid, &fcall);
1008
1009         if (retval < 0) {
1010                 dprintk(DEBUG_ERROR, "stat error\n");
1011                 goto FreeFcall;
1012         }
1013
1014         if (!fcall)
1015                 return -EIO;
1016
1017         if (!(fcall->params.rstat.stat.mode & V9FS_DMSYMLINK)) {
1018                 retval = -EINVAL;
1019                 goto FreeFcall;
1020         }
1021
1022         /* copy extension buffer into buffer */
1023         if (fcall->params.rstat.stat.extension.len < buflen)
1024                 buflen = fcall->params.rstat.stat.extension.len + 1;
1025
1026         memmove(buffer, fcall->params.rstat.stat.extension.str, buflen - 1);
1027         buffer[buflen-1] = 0;
1028
1029         dprintk(DEBUG_ERROR, "%s -> %.*s (%s)\n", dentry->d_name.name, fcall->params.rstat.stat.extension.len,
1030                 fcall->params.rstat.stat.extension.str, buffer);
1031         retval = buflen;
1032
1033       FreeFcall:
1034         kfree(fcall);
1035
1036         return retval;
1037 }
1038
1039 /**
1040  * v9fs_vfs_readlink - read a symlink's location
1041  * @dentry: dentry for symlink
1042  * @buf: buffer to load symlink location into
1043  * @buflen: length of buffer
1044  *
1045  */
1046
1047 static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer,
1048                              int buflen)
1049 {
1050         int retval;
1051         int ret;
1052         char *link = __getname();
1053
1054         if (unlikely(!link))
1055                 return -ENOMEM;
1056
1057         if (buflen > PATH_MAX)
1058                 buflen = PATH_MAX;
1059
1060         dprintk(DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_iname, dentry);
1061
1062         retval = v9fs_readlink(dentry, link, buflen);
1063
1064         if (retval > 0) {
1065                 if ((ret = copy_to_user(buffer, link, retval)) != 0) {
1066                         dprintk(DEBUG_ERROR, "problem copying to user: %d\n",
1067                                 ret);
1068                         retval = ret;
1069                 }
1070         }
1071
1072         __putname(link);
1073         return retval;
1074 }
1075
1076 /**
1077  * v9fs_vfs_follow_link - follow a symlink path
1078  * @dentry: dentry for symlink
1079  * @nd: nameidata
1080  *
1081  */
1082
1083 static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd)
1084 {
1085         int len = 0;
1086         char *link = __getname();
1087
1088         dprintk(DEBUG_VFS, "%s n", dentry->d_name.name);
1089
1090         if (!link)
1091                 link = ERR_PTR(-ENOMEM);
1092         else {
1093                 len = v9fs_readlink(dentry, link, PATH_MAX);
1094
1095                 if (len < 0) {
1096                         __putname(link);
1097                         link = ERR_PTR(len);
1098                 } else
1099                         link[len] = 0;
1100         }
1101         nd_set_link(nd, link);
1102
1103         return NULL;
1104 }
1105
1106 /**
1107  * v9fs_vfs_put_link - release a symlink path
1108  * @dentry: dentry for symlink
1109  * @nd: nameidata
1110  *
1111  */
1112
1113 static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p)
1114 {
1115         char *s = nd_get_link(nd);
1116
1117         dprintk(DEBUG_VFS, " %s %s\n", dentry->d_name.name, s);
1118         if (!IS_ERR(s))
1119                 __putname(s);
1120 }
1121
1122 static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry,
1123         int mode, const char *extension)
1124 {
1125         int err;
1126         u32 fid, perm;
1127         struct v9fs_session_info *v9ses;
1128         struct v9fs_fid *dfid, *vfid;
1129         struct inode *inode;
1130
1131         inode = NULL;
1132         vfid = NULL;
1133         v9ses = v9fs_inode2v9ses(dir);
1134         dfid = v9fs_fid_lookup(dentry->d_parent);
1135         perm = unixmode2p9mode(v9ses, mode);
1136
1137         if (!v9ses->extended) {
1138                 dprintk(DEBUG_ERROR, "not extended\n");
1139                 return -EPERM;
1140         }
1141
1142         err = v9fs_create(v9ses, dfid->fid, (char *) dentry->d_name.name,
1143                 perm, V9FS_OREAD, (char *) extension, &fid, NULL, NULL);
1144
1145         if (err)
1146                 goto error;
1147
1148         err = v9fs_t_clunk(v9ses, fid);
1149         if (err)
1150                 goto error;
1151
1152         vfid = v9fs_clone_walk(v9ses, dfid->fid, dentry);
1153         if (IS_ERR(vfid)) {
1154                 err = PTR_ERR(vfid);
1155                 vfid = NULL;
1156                 goto error;
1157         }
1158
1159         inode = v9fs_inode_from_fid(v9ses, vfid->fid, dir->i_sb);
1160         if (IS_ERR(inode)) {
1161                 err = PTR_ERR(inode);
1162                 inode = NULL;
1163                 goto error;
1164         }
1165
1166         dentry->d_op = &v9fs_dentry_operations;
1167         d_instantiate(dentry, inode);
1168         return 0;
1169
1170 error:
1171         if (vfid)
1172                 v9fs_fid_destroy(vfid);
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         if (unlikely(!name))
1228                 return -ENOMEM;
1229
1230         sprintf(name, "%d\n", oldfid->fid);
1231         retval = v9fs_vfs_mkspecial(dir, dentry, V9FS_DMLINK, name);
1232         __putname(name);
1233
1234         return retval;
1235 }
1236
1237 /**
1238  * v9fs_vfs_mknod - create a special file
1239  * @dir: inode destination for new link
1240  * @dentry: dentry for file
1241  * @mode: mode for creation
1242  * @dev_t: device associated with special file
1243  *
1244  */
1245
1246 static int
1247 v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
1248 {
1249         int retval;
1250         char *name;
1251
1252         dprintk(DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino,
1253                 dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev));
1254
1255         if (!new_valid_dev(rdev))
1256                 return -EINVAL;
1257
1258         name = __getname();
1259         if (!name)
1260                 return -ENOMEM;
1261         /* build extension */
1262         if (S_ISBLK(mode))
1263                 sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev));
1264         else if (S_ISCHR(mode))
1265                 sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev));
1266         else if (S_ISFIFO(mode))
1267                 *name = 0;
1268         else {
1269                 __putname(name);
1270                 return -EINVAL;
1271         }
1272
1273         retval = v9fs_vfs_mkspecial(dir, dentry, mode, name);
1274         __putname(name);
1275
1276         return retval;
1277 }
1278
1279 static struct inode_operations v9fs_dir_inode_operations_ext = {
1280         .create = v9fs_vfs_create,
1281         .lookup = v9fs_vfs_lookup,
1282         .symlink = v9fs_vfs_symlink,
1283         .link = v9fs_vfs_link,
1284         .unlink = v9fs_vfs_unlink,
1285         .mkdir = v9fs_vfs_mkdir,
1286         .rmdir = v9fs_vfs_rmdir,
1287         .mknod = v9fs_vfs_mknod,
1288         .rename = v9fs_vfs_rename,
1289         .readlink = v9fs_vfs_readlink,
1290         .getattr = v9fs_vfs_getattr,
1291         .setattr = v9fs_vfs_setattr,
1292 };
1293
1294 static struct inode_operations v9fs_dir_inode_operations = {
1295         .create = v9fs_vfs_create,
1296         .lookup = v9fs_vfs_lookup,
1297         .unlink = v9fs_vfs_unlink,
1298         .mkdir = v9fs_vfs_mkdir,
1299         .rmdir = v9fs_vfs_rmdir,
1300         .mknod = v9fs_vfs_mknod,
1301         .rename = v9fs_vfs_rename,
1302         .getattr = v9fs_vfs_getattr,
1303         .setattr = v9fs_vfs_setattr,
1304 };
1305
1306 static struct inode_operations v9fs_file_inode_operations = {
1307         .getattr = v9fs_vfs_getattr,
1308         .setattr = v9fs_vfs_setattr,
1309 };
1310
1311 static struct inode_operations v9fs_symlink_inode_operations = {
1312         .readlink = v9fs_vfs_readlink,
1313         .follow_link = v9fs_vfs_follow_link,
1314         .put_link = v9fs_vfs_put_link,
1315         .getattr = v9fs_vfs_getattr,
1316         .setattr = v9fs_vfs_setattr,
1317 };