fs/xfs/linux-2.6/xfs_iops.c

   1 /*
   2  * Copyright (c) 2000-2004 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32
  33 #include "xfs.h"
  34 #include "xfs_fs.h"
  35 #include "xfs_inum.h"
  36 #include "xfs_log.h"
  37 #include "xfs_trans.h"
  38 #include "xfs_sb.h"
  39 #include "xfs_ag.h"
  40 #include "xfs_dir.h"
  41 #include "xfs_dir2.h"
  42 #include "xfs_alloc.h"
  43 #include "xfs_dmapi.h"
  44 #include "xfs_quota.h"
  45 #include "xfs_mount.h"
  46 #include "xfs_alloc_btree.h"
  47 #include "xfs_bmap_btree.h"
  48 #include "xfs_ialloc_btree.h"
  49 #include "xfs_btree.h"
  50 #include "xfs_ialloc.h"
  51 #include "xfs_attr_sf.h"
  52 #include "xfs_dir_sf.h"
  53 #include "xfs_dir2_sf.h"
  54 #include "xfs_dinode.h"
  55 #include "xfs_inode.h"
  56 #include "xfs_bmap.h"
  57 #include "xfs_bit.h"
  58 #include "xfs_rtalloc.h"
  59 #include "xfs_error.h"
  60 #include "xfs_itable.h"
  61 #include "xfs_rw.h"
  62 #include "xfs_acl.h"
  63 #include "xfs_cap.h"
  64 #include "xfs_mac.h"
  65 #include "xfs_attr.h"
  66 #include "xfs_buf_item.h"
  67 #include "xfs_utils.h"
  68
  69 #include <linux/xattr.h>
  70 #include <linux/namei.h>
  71
  72
  73 /*
  74  * Pull the link count and size up from the xfs inode to the linux inode
  75  */
  76 STATIC void
  77 validate_fields(
  78         struct inode    *ip)
  79 {
  80         vnode_t         *vp = LINVFS_GET_VP(ip);
  81         vattr_t         va;
  82         int             error;
  83
  84         va.va_mask = XFS_AT_NLINK|XFS_AT_SIZE|XFS_AT_NBLOCKS;
  85         VOP_GETATTR(vp, &va, ATTR_LAZY, NULL, error);
  86         if (likely(!error)) {
  87                 ip->i_nlink = va.va_nlink;
  88                 ip->i_blocks = va.va_nblocks;
  89
  90                 /* we're under i_sem so i_size can't change under us */
  91                 if (i_size_read(ip) != va.va_size)
  92                         i_size_write(ip, va.va_size);
  93         }
  94 }
  95
  96 /*
  97  * Determine whether a process has a valid fs_struct (kernel daemons
  98  * like knfsd don't have an fs_struct).
  99  *
 100  * XXX(hch):  nfsd is broken, better fix it instead.
 101  */
 102 STATIC inline int
 103 has_fs_struct(struct task_struct *task)
 104 {
 105         return (task->fs != init_task.fs);
 106 }
 107
 108 STATIC int
 109 linvfs_mknod(
 110         struct inode    *dir,
 111         struct dentry   *dentry,
 112         int             mode,
 113         dev_t           rdev)
 114 {
 115         struct inode    *ip;
 116         vattr_t         va;
 117         vnode_t         *vp = NULL, *dvp = LINVFS_GET_VP(dir);
 118         xfs_acl_t       *default_acl = NULL;
 119         attrexists_t    test_default_acl = _ACL_DEFAULT_EXISTS;
 120         int             error;
 121
 122         /*
 123          * Irix uses Missed'em'V split, but doesn't want to see
 124          * the upper 5 bits of (14bit) major.
 125          */
 126         if (!sysv_valid_dev(rdev) || MAJOR(rdev) & ~0x1ff)
 127                 return -EINVAL;
 128
 129         if (test_default_acl && test_default_acl(dvp)) {
 130                 if (!_ACL_ALLOC(default_acl))
 131                         return -ENOMEM;
 132                 if (!_ACL_GET_DEFAULT(dvp, default_acl)) {
 133                         _ACL_FREE(default_acl);
 134                         default_acl = NULL;
 135                 }
 136         }
 137
 138         if (IS_POSIXACL(dir) && !default_acl && has_fs_struct(current))
 139                 mode &= ~current->fs->umask;
 140
 141         memset(&va, 0, sizeof(va));
 142         va.va_mask = XFS_AT_TYPE|XFS_AT_MODE;
 143         va.va_mode = mode;
 144
 145         switch (mode & S_IFMT) {
 146         case S_IFCHR: case S_IFBLK: case S_IFIFO: case S_IFSOCK:
 147                 va.va_rdev = sysv_encode_dev(rdev);
 148                 va.va_mask |= XFS_AT_RDEV;
 149                 /*FALLTHROUGH*/
 150         case S_IFREG:
 151                 VOP_CREATE(dvp, dentry, &va, &vp, NULL, error);
 152                 break;
 153         case S_IFDIR:
 154                 VOP_MKDIR(dvp, dentry, &va, &vp, NULL, error);
 155                 break;
 156         default:
 157                 error = EINVAL;
 158                 break;
 159         }
 160
 161         if (default_acl) {
 162                 if (!error) {
 163                         error = _ACL_INHERIT(vp, &va, default_acl);
 164                         if (!error) {
 165                                 VMODIFY(vp);
 166                         } else {
 167                                 struct dentry   teardown = {};
 168                                 int             err2;
 169
 170                                 /* Oh, the horror.
 171                                  * If we can't add the ACL we must back out.
 172                                  * ENOSPC can hit here, among other things.
 173                                  */
 174                                 teardown.d_inode = ip = LINVFS_GET_IP(vp);
 175                                 teardown.d_name = dentry->d_name;
 176
 177                                 vn_mark_bad(vp);
 178
 179                                 if (S_ISDIR(mode))
 180                                         VOP_RMDIR(dvp, &teardown, NULL, err2);
 181                                 else
 182                                         VOP_REMOVE(dvp, &teardown, NULL, err2);
 183                                 VN_RELE(vp);
 184                         }
 185                 }
 186                 _ACL_FREE(default_acl);
 187         }
 188
 189         if (!error) {
 190                 ASSERT(vp);
 191                 ip = LINVFS_GET_IP(vp);
 192
 193                 if (S_ISCHR(mode) || S_ISBLK(mode))
 194                         ip->i_rdev = rdev;
 195                 else if (S_ISDIR(mode))
 196                         validate_fields(ip);
 197                 d_instantiate(dentry, ip);
 198                 validate_fields(dir);
 199         }
 200         return -error;
 201 }
 202
 203 STATIC int
 204 linvfs_create(
 205         struct inode    *dir,
 206         struct dentry   *dentry,
 207         int             mode,
 208         struct nameidata *nd)
 209 {
 210         return linvfs_mknod(dir, dentry, mode, 0);
 211 }
 212
 213 STATIC int
 214 linvfs_mkdir(
 215         struct inode    *dir,
 216         struct dentry   *dentry,
 217         int             mode)
 218 {
 219         return linvfs_mknod(dir, dentry, mode|S_IFDIR, 0);
 220 }
 221
 222 STATIC struct dentry *
 223 linvfs_lookup(
 224         struct inode    *dir,
 225         struct dentry   *dentry,
 226         struct nameidata *nd)
 227 {
 228         struct vnode    *vp = LINVFS_GET_VP(dir), *cvp;
 229         int             error;
 230
 231         if (dentry->d_name.len >= MAXNAMELEN)
 232                 return ERR_PTR(-ENAMETOOLONG);
 233
 234         VOP_LOOKUP(vp, dentry, &cvp, 0, NULL, NULL, error);
 235         if (error) {
 236                 if (unlikely(error != ENOENT))
 237                         return ERR_PTR(-error);
 238                 d_add(dentry, NULL);
 239                 return NULL;
 240         }
 241
 242         return d_splice_alias(LINVFS_GET_IP(cvp), dentry);
 243 }
 244
 245 STATIC int
 246 linvfs_link(
 247         struct dentry   *old_dentry,
 248         struct inode    *dir,
 249         struct dentry   *dentry)
 250 {
 251         struct inode    *ip;    /* inode of guy being linked to */
 252         vnode_t         *tdvp;  /* target directory for new name/link */
 253         vnode_t         *vp;    /* vp of name being linked */
 254         int             error;
 255
 256         ip = old_dentry->d_inode;       /* inode being linked to */
 257         if (S_ISDIR(ip->i_mode))
 258                 return -EPERM;
 259
 260         tdvp = LINVFS_GET_VP(dir);
 261         vp = LINVFS_GET_VP(ip);
 262
 263         VOP_LINK(tdvp, vp, dentry, NULL, error);
 264         if (!error) {
 265                 VMODIFY(tdvp);
 266                 VN_HOLD(vp);
 267                 validate_fields(ip);
 268                 d_instantiate(dentry, ip);
 269         }
 270         return -error;
 271 }
 272
 273 STATIC int
 274 linvfs_unlink(
 275         struct inode    *dir,
 276         struct dentry   *dentry)
 277 {
 278         struct inode    *inode;
 279         vnode_t         *dvp;   /* directory containing name to remove */
 280         int             error;
 281
 282         inode = dentry->d_inode;
 283         dvp = LINVFS_GET_VP(dir);
 284
 285         VOP_REMOVE(dvp, dentry, NULL, error);
 286         if (!error) {
 287                 validate_fields(dir);   /* For size only */
 288                 validate_fields(inode);
 289         }
 290
 291         return -error;
 292 }
 293
 294 STATIC int
 295 linvfs_symlink(
 296         struct inode    *dir,
 297         struct dentry   *dentry,
 298         const char      *symname)
 299 {
 300         struct inode    *ip;
 301         vattr_t         va;
 302         vnode_t         *dvp;   /* directory containing name of symlink */
 303         vnode_t         *cvp;   /* used to lookup symlink to put in dentry */
 304         int             error;
 305
 306         dvp = LINVFS_GET_VP(dir);
 307         cvp = NULL;
 308
 309         memset(&va, 0, sizeof(va));
 310         va.va_mode = S_IFLNK |
 311                 (irix_symlink_mode ? 0777 & ~current->fs->umask : S_IRWXUGO);
 312         va.va_mask = XFS_AT_TYPE|XFS_AT_MODE;
 313
 314         error = 0;
 315         VOP_SYMLINK(dvp, dentry, &va, (char *)symname, &cvp, NULL, error);
 316         if (!error && cvp) {
 317                 ip = LINVFS_GET_IP(cvp);
 318                 d_instantiate(dentry, ip);
 319                 validate_fields(dir);
 320                 validate_fields(ip); /* size needs update */
 321         }
 322         return -error;
 323 }
 324
 325 STATIC int
 326 linvfs_rmdir(
 327         struct inode    *dir,
 328         struct dentry   *dentry)
 329 {
 330         struct inode    *inode = dentry->d_inode;
 331         vnode_t         *dvp = LINVFS_GET_VP(dir);
 332         int             error;
 333
 334         VOP_RMDIR(dvp, dentry, NULL, error);
 335         if (!error) {
 336                 validate_fields(inode);
 337                 validate_fields(dir);
 338         }
 339         return -error;
 340 }
 341
 342 STATIC int
 343 linvfs_rename(
 344         struct inode    *odir,
 345         struct dentry   *odentry,
 346         struct inode    *ndir,
 347         struct dentry   *ndentry)
 348 {
 349         struct inode    *new_inode = ndentry->d_inode;
 350         vnode_t         *fvp;   /* from directory */
 351         vnode_t         *tvp;   /* target directory */
 352         int             error;
 353
 354         fvp = LINVFS_GET_VP(odir);
 355         tvp = LINVFS_GET_VP(ndir);
 356
 357         VOP_RENAME(fvp, odentry, tvp, ndentry, NULL, error);
 358         if (error)
 359                 return -error;
 360
 361         if (new_inode)
 362                 validate_fields(new_inode);
 363
 364         validate_fields(odir);
 365         if (ndir != odir)
 366                 validate_fields(ndir);
 367         return 0;
 368 }
 369
 370 /*
 371  * careful here - this function can get called recursively, so
 372  * we need to be very careful about how much stack we use.
 373  * uio is kmalloced for this reason...
 374  */
 375 STATIC void *
 376 linvfs_follow_link(
 377         struct dentry           *dentry,
 378         struct nameidata        *nd)
 379 {
 380         vnode_t                 *vp;
 381         uio_t                   *uio;
 382         iovec_t                 iov;
 383         int                     error;
 384         char                    *link;
 385
 386         ASSERT(dentry);
 387         ASSERT(nd);
 388
 389         link = (char *)kmalloc(MAXNAMELEN+1, GFP_KERNEL);
 390         if (!link) {
 391                 nd_set_link(nd, ERR_PTR(-ENOMEM));
 392                 return NULL;
 393         }
 394
 395         uio = (uio_t *)kmalloc(sizeof(uio_t), GFP_KERNEL);
 396         if (!uio) {
 397                 kfree(link);
 398                 nd_set_link(nd, ERR_PTR(-ENOMEM));
 399                 return NULL;
 400         }
 401
 402         vp = LINVFS_GET_VP(dentry->d_inode);
 403
 404         iov.iov_base = link;
 405         iov.iov_len = MAXNAMELEN;
 406
 407         uio->uio_iov = &iov;
 408         uio->uio_offset = 0;
 409         uio->uio_segflg = UIO_SYSSPACE;
 410         uio->uio_resid = MAXNAMELEN;
 411         uio->uio_iovcnt = 1;
 412
 413         VOP_READLINK(vp, uio, 0, NULL, error);
 414         if (error) {
 415                 kfree(link);
 416                 link = ERR_PTR(-error);
 417         } else {
 418                 link[MAXNAMELEN - uio->uio_resid] = '\0';
 419         }
 420         kfree(uio);
 421
 422         nd_set_link(nd, link);
 423         return NULL;
 424 }
 425
 426 STATIC void
 427 linvfs_put_link(
 428         struct dentry   *dentry,
 429         struct nameidata *nd,
 430         void            *p)
 431 {
 432         char            *s = nd_get_link(nd);
 433
 434         if (!IS_ERR(s))
 435                 kfree(s);
 436 }
 437
 438 #ifdef CONFIG_XFS_POSIX_ACL
 439 STATIC int
 440 linvfs_permission(
 441         struct inode    *inode,
 442         int             mode,
 443         struct nameidata *nd)
 444 {
 445         vnode_t         *vp = LINVFS_GET_VP(inode);
 446         int             error;
 447
 448         mode <<= 6;             /* convert from linux to vnode access bits */
 449         VOP_ACCESS(vp, mode, NULL, error);
 450         return -error;
 451 }
 452 #else
 453 #define linvfs_permission NULL
 454 #endif
 455
 456 STATIC int
 457 linvfs_getattr(
 458         struct vfsmount *mnt,
 459         struct dentry   *dentry,
 460         struct kstat    *stat)
 461 {
 462         struct inode    *inode = dentry->d_inode;
 463         vnode_t         *vp = LINVFS_GET_VP(inode);
 464         int             error = 0;
 465
 466         if (unlikely(vp->v_flag & VMODIFIED))
 467                 error = vn_revalidate(vp);
 468         if (!error)
 469                 generic_fillattr(inode, stat);
 470         return 0;
 471 }
 472
 473 STATIC int
 474 linvfs_setattr(
 475         struct dentry   *dentry,
 476         struct iattr    *attr)
 477 {
 478         struct inode    *inode = dentry->d_inode;
 479         unsigned int    ia_valid = attr->ia_valid;
 480         vnode_t         *vp = LINVFS_GET_VP(inode);
 481         vattr_t         vattr;
 482         int             flags = 0;
 483         int             error;
 484
 485         memset(&vattr, 0, sizeof(vattr_t));
 486         if (ia_valid & ATTR_UID) {
 487                 vattr.va_mask |= XFS_AT_UID;
 488                 vattr.va_uid = attr->ia_uid;
 489         }
 490         if (ia_valid & ATTR_GID) {
 491                 vattr.va_mask |= XFS_AT_GID;
 492                 vattr.va_gid = attr->ia_gid;
 493         }
 494         if (ia_valid & ATTR_SIZE) {
 495                 vattr.va_mask |= XFS_AT_SIZE;
 496                 vattr.va_size = attr->ia_size;
 497         }
 498         if (ia_valid & ATTR_ATIME) {
 499                 vattr.va_mask |= XFS_AT_ATIME;
 500                 vattr.va_atime = attr->ia_atime;
 501         }
 502         if (ia_valid & ATTR_MTIME) {
 503                 vattr.va_mask |= XFS_AT_MTIME;
 504                 vattr.va_mtime = attr->ia_mtime;
 505         }
 506         if (ia_valid & ATTR_CTIME) {
 507                 vattr.va_mask |= XFS_AT_CTIME;
 508                 vattr.va_ctime = attr->ia_ctime;
 509         }
 510         if (ia_valid & ATTR_MODE) {
 511                 vattr.va_mask |= XFS_AT_MODE;
 512                 vattr.va_mode = attr->ia_mode;
 513                 if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
 514                         inode->i_mode &= ~S_ISGID;
 515         }
 516
 517         if (ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET))
 518                 flags |= ATTR_UTIME;
 519 #ifdef ATTR_NO_BLOCK
 520         if ((ia_valid & ATTR_NO_BLOCK))
 521                 flags |= ATTR_NONBLOCK;
 522 #endif
 523
 524         VOP_SETATTR(vp, &vattr, flags, NULL, error);
 525         if (error)
 526                 return -error;
 527         vn_revalidate(vp);
 528         return error;
 529 }
 530
 531 STATIC void
 532 linvfs_truncate(
 533         struct inode    *inode)
 534 {
 535         block_truncate_page(inode->i_mapping, inode->i_size, linvfs_get_block);
 536 }
 537
 538 STATIC int
 539 linvfs_setxattr(
 540         struct dentry   *dentry,
 541         const char      *name,
 542         const void      *data,
 543         size_t          size,
 544         int             flags)
 545 {
 546         vnode_t         *vp = LINVFS_GET_VP(dentry->d_inode);
 547         char            *attr = (char *)name;
 548         attrnames_t     *namesp;
 549         int             xflags = 0;
 550         int             error;
 551
 552         namesp = attr_lookup_namespace(attr, attr_namespaces, ATTR_NAMECOUNT);
 553         if (!namesp)
 554                 return -EOPNOTSUPP;
 555         attr += namesp->attr_namelen;
 556         error = namesp->attr_capable(vp, NULL);
 557         if (error)
 558                 return error;
 559
 560         /* Convert Linux syscall to XFS internal ATTR flags */
 561         if (flags & XATTR_CREATE)
 562                 xflags |= ATTR_CREATE;
 563         if (flags & XATTR_REPLACE)
 564                 xflags |= ATTR_REPLACE;
 565         xflags |= namesp->attr_flag;
 566         return namesp->attr_set(vp, attr, (void *)data, size, xflags);
 567 }
 568
 569 STATIC ssize_t
 570 linvfs_getxattr(
 571         struct dentry   *dentry,
 572         const char      *name,
 573         void            *data,
 574         size_t          size)
 575 {
 576         vnode_t         *vp = LINVFS_GET_VP(dentry->d_inode);
 577         char            *attr = (char *)name;
 578         attrnames_t     *namesp;
 579         int             xflags = 0;
 580         ssize_t         error;
 581
 582         namesp = attr_lookup_namespace(attr, attr_namespaces, ATTR_NAMECOUNT);
 583         if (!namesp)
 584                 return -EOPNOTSUPP;
 585         attr += namesp->attr_namelen;
 586         error = namesp->attr_capable(vp, NULL);
 587         if (error)
 588                 return error;
 589
 590         /* Convert Linux syscall to XFS internal ATTR flags */
 591         if (!size) {
 592                 xflags |= ATTR_KERNOVAL;
 593                 data = NULL;
 594         }
 595         xflags |= namesp->attr_flag;
 596         return namesp->attr_get(vp, attr, (void *)data, size, xflags);
 597 }
 598
 599 STATIC ssize_t
 600 linvfs_listxattr(
 601         struct dentry           *dentry,
 602         char                    *data,
 603         size_t                  size)
 604 {
 605         vnode_t                 *vp = LINVFS_GET_VP(dentry->d_inode);
 606         int                     error, xflags = ATTR_KERNAMELS;
 607         ssize_t                 result;
 608
 609         if (!size)
 610                 xflags |= ATTR_KERNOVAL;
 611         xflags |= capable(CAP_SYS_ADMIN) ? ATTR_KERNFULLS : ATTR_KERNORMALS;
 612
 613         error = attr_generic_list(vp, data, size, xflags, &result);
 614         if (error < 0)
 615                 return error;
 616         return result;
 617 }
 618
 619 STATIC int
 620 linvfs_removexattr(
 621         struct dentry   *dentry,
 622         const char      *name)
 623 {
 624         vnode_t         *vp = LINVFS_GET_VP(dentry->d_inode);
 625         char            *attr = (char *)name;
 626         attrnames_t     *namesp;
 627         int             xflags = 0;
 628         int             error;
 629
 630         namesp = attr_lookup_namespace(attr, attr_namespaces, ATTR_NAMECOUNT);
 631         if (!namesp)
 632                 return -EOPNOTSUPP;
 633         attr += namesp->attr_namelen;
 634         error = namesp->attr_capable(vp, NULL);
 635         if (error)
 636                 return error;
 637         xflags |= namesp->attr_flag;
 638         return namesp->attr_remove(vp, attr, xflags);
 639 }
 640
 641
 642 struct inode_operations linvfs_file_inode_operations = {
 643         .permission             = linvfs_permission,
 644         .truncate               = linvfs_truncate,
 645         .getattr                = linvfs_getattr,
 646         .setattr                = linvfs_setattr,
 647         .setxattr               = linvfs_setxattr,
 648         .getxattr               = linvfs_getxattr,
 649         .listxattr              = linvfs_listxattr,
 650         .removexattr            = linvfs_removexattr,
 651 };
 652
 653 struct inode_operations linvfs_dir_inode_operations = {
 654         .create                 = linvfs_create,
 655         .lookup                 = linvfs_lookup,
 656         .link                   = linvfs_link,
 657         .unlink                 = linvfs_unlink,
 658         .symlink                = linvfs_symlink,
 659         .mkdir                  = linvfs_mkdir,
 660         .rmdir                  = linvfs_rmdir,
 661         .mknod                  = linvfs_mknod,
 662         .rename                 = linvfs_rename,
 663         .permission             = linvfs_permission,
 664         .getattr                = linvfs_getattr,
 665         .setattr                = linvfs_setattr,
 666         .setxattr               = linvfs_setxattr,
 667         .getxattr               = linvfs_getxattr,
 668         .listxattr              = linvfs_listxattr,
 669         .removexattr            = linvfs_removexattr,
 670 };
 671
 672 struct inode_operations linvfs_symlink_inode_operations = {
 673         .readlink               = generic_readlink,
 674         .follow_link            = linvfs_follow_link,
 675         .put_link               = linvfs_put_link,
 676         .permission             = linvfs_permission,
 677         .getattr                = linvfs_getattr,
 678         .setattr                = linvfs_setattr,
 679         .setxattr               = linvfs_setxattr,
 680         .getxattr               = linvfs_getxattr,
 681         .listxattr              = linvfs_listxattr,
 682         .removexattr            = linvfs_removexattr,
 683 };