1 /* 2 * File operations used by nfsd. Some of these have been ripped from 3 * other parts of the kernel because they weren't exported, others 4 * are partial duplicates with added or changed functionality. 5 * 6 * Note that several functions dget() the dentry upon which they want 7 * to act, most notably those that create directory entries. Response 8 * dentry's are dput()'d if necessary in the release callback. 9 * So if you notice code paths that apparently fail to dput() the 10 * dentry, don't worry--they have been taken care of. 11 * 12 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de> 13 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp> 14 */ 15 16 #include <linux/fs.h> 17 #include <linux/file.h> 18 #include <linux/splice.h> 19 #include <linux/fcntl.h> 20 #include <linux/namei.h> 21 #include <linux/delay.h> 22 #include <linux/fsnotify.h> 23 #include <linux/posix_acl_xattr.h> 24 #include <linux/xattr.h> 25 #include <linux/jhash.h> 26 #include <linux/ima.h> 27 #include <linux/slab.h> 28 #include <asm/uaccess.h> 29 #include <linux/exportfs.h> 30 #include <linux/writeback.h> 31 32 #ifdef CONFIG_NFSD_V3 33 #include "xdr3.h" 34 #endif /* CONFIG_NFSD_V3 */ 35 36 #ifdef CONFIG_NFSD_V4 37 #include "acl.h" 38 #include "idmap.h" 39 #endif /* CONFIG_NFSD_V4 */ 40 41 #include "nfsd.h" 42 #include "vfs.h" 43 44 #define NFSDDBG_FACILITY NFSDDBG_FILEOP 45 46 47 /* 48 * This is a cache of readahead params that help us choose the proper 49 * readahead strategy. Initially, we set all readahead parameters to 0 50 * and let the VFS handle things. 51 * If you increase the number of cached files very much, you'll need to 52 * add a hash table here. 53 */ 54 struct raparms { 55 struct raparms *p_next; 56 unsigned int p_count; 57 ino_t p_ino; 58 dev_t p_dev; 59 int p_set; 60 struct file_ra_state p_ra; 61 unsigned int p_hindex; 62 }; 63 64 struct raparm_hbucket { 65 struct raparms *pb_head; 66 spinlock_t pb_lock; 67 } ____cacheline_aligned_in_smp; 68 69 #define RAPARM_HASH_BITS 4 70 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS) 71 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1) 72 static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE]; 73 74 /* 75 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 76 * a mount point. 77 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged, 78 * or nfs_ok having possibly changed *dpp and *expp 79 */ 80 int 81 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 82 struct svc_export **expp) 83 { 84 struct svc_export *exp = *expp, *exp2 = NULL; 85 struct dentry *dentry = *dpp; 86 struct path path = {.mnt = mntget(exp->ex_path.mnt), 87 .dentry = dget(dentry)}; 88 int err = 0; 89 90 err = follow_down(&path); 91 if (err < 0) 92 goto out; 93 94 exp2 = rqst_exp_get_by_name(rqstp, &path); 95 if (IS_ERR(exp2)) { 96 err = PTR_ERR(exp2); 97 /* 98 * We normally allow NFS clients to continue 99 * "underneath" a mountpoint that is not exported. 100 * The exception is V4ROOT, where no traversal is ever 101 * allowed without an explicit export of the new 102 * directory. 103 */ 104 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT)) 105 err = 0; 106 path_put(&path); 107 goto out; 108 } 109 if (nfsd_v4client(rqstp) || 110 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) { 111 /* successfully crossed mount point */ 112 /* 113 * This is subtle: path.dentry is *not* on path.mnt 114 * at this point. The only reason we are safe is that 115 * original mnt is pinned down by exp, so we should 116 * put path *before* putting exp 117 */ 118 *dpp = path.dentry; 119 path.dentry = dentry; 120 *expp = exp2; 121 exp2 = exp; 122 } 123 path_put(&path); 124 exp_put(exp2); 125 out: 126 return err; 127 } 128 129 static void follow_to_parent(struct path *path) 130 { 131 struct dentry *dp; 132 133 while (path->dentry == path->mnt->mnt_root && follow_up(path)) 134 ; 135 dp = dget_parent(path->dentry); 136 dput(path->dentry); 137 path->dentry = dp; 138 } 139 140 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp) 141 { 142 struct svc_export *exp2; 143 struct path path = {.mnt = mntget((*exp)->ex_path.mnt), 144 .dentry = dget(dparent)}; 145 146 follow_to_parent(&path); 147 148 exp2 = rqst_exp_parent(rqstp, &path); 149 if (PTR_ERR(exp2) == -ENOENT) { 150 *dentryp = dget(dparent); 151 } else if (IS_ERR(exp2)) { 152 path_put(&path); 153 return PTR_ERR(exp2); 154 } else { 155 *dentryp = dget(path.dentry); 156 exp_put(*exp); 157 *exp = exp2; 158 } 159 path_put(&path); 160 return 0; 161 } 162 163 /* 164 * For nfsd purposes, we treat V4ROOT exports as though there was an 165 * export at *every* directory. 166 */ 167 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) 168 { 169 if (d_mountpoint(dentry)) 170 return 1; 171 if (!(exp->ex_flags & NFSEXP_V4ROOT)) 172 return 0; 173 return dentry->d_inode != NULL; 174 } 175 176 __be32 177 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, 178 const char *name, unsigned int len, 179 struct svc_export **exp_ret, struct dentry **dentry_ret) 180 { 181 struct svc_export *exp; 182 struct dentry *dparent; 183 struct dentry *dentry; 184 int host_err; 185 186 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); 187 188 dparent = fhp->fh_dentry; 189 exp = fhp->fh_export; 190 exp_get(exp); 191 192 /* Lookup the name, but don't follow links */ 193 if (isdotent(name, len)) { 194 if (len==1) 195 dentry = dget(dparent); 196 else if (dparent != exp->ex_path.dentry) 197 dentry = dget_parent(dparent); 198 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp)) 199 dentry = dget(dparent); /* .. == . just like at / */ 200 else { 201 /* checking mountpoint crossing is very different when stepping up */ 202 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry); 203 if (host_err) 204 goto out_nfserr; 205 } 206 } else { 207 fh_lock(fhp); 208 dentry = lookup_one_len(name, dparent, len); 209 host_err = PTR_ERR(dentry); 210 if (IS_ERR(dentry)) 211 goto out_nfserr; 212 /* 213 * check if we have crossed a mount point ... 214 */ 215 if (nfsd_mountpoint(dentry, exp)) { 216 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) { 217 dput(dentry); 218 goto out_nfserr; 219 } 220 } 221 } 222 *dentry_ret = dentry; 223 *exp_ret = exp; 224 return 0; 225 226 out_nfserr: 227 exp_put(exp); 228 return nfserrno(host_err); 229 } 230 231 /* 232 * Look up one component of a pathname. 233 * N.B. After this call _both_ fhp and resfh need an fh_put 234 * 235 * If the lookup would cross a mountpoint, and the mounted filesystem 236 * is exported to the client with NFSEXP_NOHIDE, then the lookup is 237 * accepted as it stands and the mounted directory is 238 * returned. Otherwise the covered directory is returned. 239 * NOTE: this mountpoint crossing is not supported properly by all 240 * clients and is explicitly disallowed for NFSv3 241 * NeilBrown <neilb@cse.unsw.edu.au> 242 */ 243 __be32 244 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, 245 unsigned int len, struct svc_fh *resfh) 246 { 247 struct svc_export *exp; 248 struct dentry *dentry; 249 __be32 err; 250 251 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); 252 if (err) 253 return err; 254 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry); 255 if (err) 256 return err; 257 err = check_nfsd_access(exp, rqstp); 258 if (err) 259 goto out; 260 /* 261 * Note: we compose the file handle now, but as the 262 * dentry may be negative, it may need to be updated. 263 */ 264 err = fh_compose(resfh, exp, dentry, fhp); 265 if (!err && !dentry->d_inode) 266 err = nfserr_noent; 267 out: 268 dput(dentry); 269 exp_put(exp); 270 return err; 271 } 272 273 static int nfsd_break_lease(struct inode *inode) 274 { 275 if (!S_ISREG(inode->i_mode)) 276 return 0; 277 return break_lease(inode, O_WRONLY | O_NONBLOCK); 278 } 279 280 /* 281 * Commit metadata changes to stable storage. 282 */ 283 static int 284 commit_metadata(struct svc_fh *fhp) 285 { 286 struct inode *inode = fhp->fh_dentry->d_inode; 287 const struct export_operations *export_ops = inode->i_sb->s_export_op; 288 289 if (!EX_ISSYNC(fhp->fh_export)) 290 return 0; 291 292 if (export_ops->commit_metadata) 293 return export_ops->commit_metadata(inode); 294 return sync_inode_metadata(inode, 1); 295 } 296 297 /* 298 * Set various file attributes. 299 * N.B. After this call fhp needs an fh_put 300 */ 301 __be32 302 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 303 int check_guard, time_t guardtime) 304 { 305 struct dentry *dentry; 306 struct inode *inode; 307 int accmode = NFSD_MAY_SATTR; 308 int ftype = 0; 309 __be32 err; 310 int host_err; 311 int size_change = 0; 312 313 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 314 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; 315 if (iap->ia_valid & ATTR_SIZE) 316 ftype = S_IFREG; 317 318 /* Get inode */ 319 err = fh_verify(rqstp, fhp, ftype, accmode); 320 if (err) 321 goto out; 322 323 dentry = fhp->fh_dentry; 324 inode = dentry->d_inode; 325 326 /* Ignore any mode updates on symlinks */ 327 if (S_ISLNK(inode->i_mode)) 328 iap->ia_valid &= ~ATTR_MODE; 329 330 if (!iap->ia_valid) 331 goto out; 332 333 /* 334 * NFSv2 does not differentiate between "set-[ac]time-to-now" 335 * which only requires access, and "set-[ac]time-to-X" which 336 * requires ownership. 337 * So if it looks like it might be "set both to the same time which 338 * is close to now", and if inode_change_ok fails, then we 339 * convert to "set to now" instead of "set to explicit time" 340 * 341 * We only call inode_change_ok as the last test as technically 342 * it is not an interface that we should be using. It is only 343 * valid if the filesystem does not define it's own i_op->setattr. 344 */ 345 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 346 #define MAX_TOUCH_TIME_ERROR (30*60) 347 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && 348 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) { 349 /* 350 * Looks probable. 351 * 352 * Now just make sure time is in the right ballpark. 353 * Solaris, at least, doesn't seem to care what the time 354 * request is. We require it be within 30 minutes of now. 355 */ 356 time_t delta = iap->ia_atime.tv_sec - get_seconds(); 357 if (delta < 0) 358 delta = -delta; 359 if (delta < MAX_TOUCH_TIME_ERROR && 360 inode_change_ok(inode, iap) != 0) { 361 /* 362 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME. 363 * This will cause notify_change to set these times 364 * to "now" 365 */ 366 iap->ia_valid &= ~BOTH_TIME_SET; 367 } 368 } 369 370 /* 371 * The size case is special. 372 * It changes the file as well as the attributes. 373 */ 374 if (iap->ia_valid & ATTR_SIZE) { 375 if (iap->ia_size < inode->i_size) { 376 err = nfsd_permission(rqstp, fhp->fh_export, dentry, 377 NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE); 378 if (err) 379 goto out; 380 } 381 382 host_err = get_write_access(inode); 383 if (host_err) 384 goto out_nfserr; 385 386 size_change = 1; 387 host_err = locks_verify_truncate(inode, NULL, iap->ia_size); 388 if (host_err) { 389 put_write_access(inode); 390 goto out_nfserr; 391 } 392 } 393 394 /* sanitize the mode change */ 395 if (iap->ia_valid & ATTR_MODE) { 396 iap->ia_mode &= S_IALLUGO; 397 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); 398 } 399 400 /* Revoke setuid/setgid on chown */ 401 if (!S_ISDIR(inode->i_mode) && 402 (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) || 403 ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) { 404 iap->ia_valid |= ATTR_KILL_PRIV; 405 if (iap->ia_valid & ATTR_MODE) { 406 /* we're setting mode too, just clear the s*id bits */ 407 iap->ia_mode &= ~S_ISUID; 408 if (iap->ia_mode & S_IXGRP) 409 iap->ia_mode &= ~S_ISGID; 410 } else { 411 /* set ATTR_KILL_* bits and let VFS handle it */ 412 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID); 413 } 414 } 415 416 /* Change the attributes. */ 417 418 iap->ia_valid |= ATTR_CTIME; 419 420 err = nfserr_notsync; 421 if (!check_guard || guardtime == inode->i_ctime.tv_sec) { 422 host_err = nfsd_break_lease(inode); 423 if (host_err) 424 goto out_nfserr; 425 fh_lock(fhp); 426 427 host_err = notify_change(dentry, iap); 428 err = nfserrno(host_err); 429 fh_unlock(fhp); 430 } 431 if (size_change) 432 put_write_access(inode); 433 if (!err) 434 commit_metadata(fhp); 435 out: 436 return err; 437 438 out_nfserr: 439 err = nfserrno(host_err); 440 goto out; 441 } 442 443 #if defined(CONFIG_NFSD_V2_ACL) || \ 444 defined(CONFIG_NFSD_V3_ACL) || \ 445 defined(CONFIG_NFSD_V4) 446 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf) 447 { 448 ssize_t buflen; 449 ssize_t ret; 450 451 buflen = vfs_getxattr(dentry, key, NULL, 0); 452 if (buflen <= 0) 453 return buflen; 454 455 *buf = kmalloc(buflen, GFP_KERNEL); 456 if (!*buf) 457 return -ENOMEM; 458 459 ret = vfs_getxattr(dentry, key, *buf, buflen); 460 if (ret < 0) 461 kfree(*buf); 462 return ret; 463 } 464 #endif 465 466 #if defined(CONFIG_NFSD_V4) 467 static int 468 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key) 469 { 470 int len; 471 size_t buflen; 472 char *buf = NULL; 473 int error = 0; 474 475 buflen = posix_acl_xattr_size(pacl->a_count); 476 buf = kmalloc(buflen, GFP_KERNEL); 477 error = -ENOMEM; 478 if (buf == NULL) 479 goto out; 480 481 len = posix_acl_to_xattr(pacl, buf, buflen); 482 if (len < 0) { 483 error = len; 484 goto out; 485 } 486 487 error = vfs_setxattr(dentry, key, buf, len, 0); 488 out: 489 kfree(buf); 490 return error; 491 } 492 493 __be32 494 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 495 struct nfs4_acl *acl) 496 { 497 __be32 error; 498 int host_error; 499 struct dentry *dentry; 500 struct inode *inode; 501 struct posix_acl *pacl = NULL, *dpacl = NULL; 502 unsigned int flags = 0; 503 504 /* Get inode */ 505 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); 506 if (error) 507 return error; 508 509 dentry = fhp->fh_dentry; 510 inode = dentry->d_inode; 511 if (S_ISDIR(inode->i_mode)) 512 flags = NFS4_ACL_DIR; 513 514 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 515 if (host_error == -EINVAL) { 516 return nfserr_attrnotsupp; 517 } else if (host_error < 0) 518 goto out_nfserr; 519 520 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); 521 if (host_error < 0) 522 goto out_release; 523 524 if (S_ISDIR(inode->i_mode)) 525 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); 526 527 out_release: 528 posix_acl_release(pacl); 529 posix_acl_release(dpacl); 530 out_nfserr: 531 if (host_error == -EOPNOTSUPP) 532 return nfserr_attrnotsupp; 533 else 534 return nfserrno(host_error); 535 } 536 537 static struct posix_acl * 538 _get_posix_acl(struct dentry *dentry, char *key) 539 { 540 void *buf = NULL; 541 struct posix_acl *pacl = NULL; 542 int buflen; 543 544 buflen = nfsd_getxattr(dentry, key, &buf); 545 if (!buflen) 546 buflen = -ENODATA; 547 if (buflen <= 0) 548 return ERR_PTR(buflen); 549 550 pacl = posix_acl_from_xattr(buf, buflen); 551 kfree(buf); 552 return pacl; 553 } 554 555 int 556 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl) 557 { 558 struct inode *inode = dentry->d_inode; 559 int error = 0; 560 struct posix_acl *pacl = NULL, *dpacl = NULL; 561 unsigned int flags = 0; 562 563 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS); 564 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA) 565 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 566 if (IS_ERR(pacl)) { 567 error = PTR_ERR(pacl); 568 pacl = NULL; 569 goto out; 570 } 571 572 if (S_ISDIR(inode->i_mode)) { 573 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT); 574 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA) 575 dpacl = NULL; 576 else if (IS_ERR(dpacl)) { 577 error = PTR_ERR(dpacl); 578 dpacl = NULL; 579 goto out; 580 } 581 flags = NFS4_ACL_DIR; 582 } 583 584 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags); 585 if (IS_ERR(*acl)) { 586 error = PTR_ERR(*acl); 587 *acl = NULL; 588 } 589 out: 590 posix_acl_release(pacl); 591 posix_acl_release(dpacl); 592 return error; 593 } 594 595 #endif /* defined(CONFIG_NFSD_V4) */ 596 597 #ifdef CONFIG_NFSD_V3 598 /* 599 * Check server access rights to a file system object 600 */ 601 struct accessmap { 602 u32 access; 603 int how; 604 }; 605 static struct accessmap nfs3_regaccess[] = { 606 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 607 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 608 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, 609 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, 610 611 { 0, 0 } 612 }; 613 614 static struct accessmap nfs3_diraccess[] = { 615 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 616 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, 617 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, 618 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, 619 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, 620 621 { 0, 0 } 622 }; 623 624 static struct accessmap nfs3_anyaccess[] = { 625 /* Some clients - Solaris 2.6 at least, make an access call 626 * to the server to check for access for things like /dev/null 627 * (which really, the server doesn't care about). So 628 * We provide simple access checking for them, looking 629 * mainly at mode bits, and we make sure to ignore read-only 630 * filesystem checks 631 */ 632 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 633 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 634 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 635 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 636 637 { 0, 0 } 638 }; 639 640 __be32 641 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 642 { 643 struct accessmap *map; 644 struct svc_export *export; 645 struct dentry *dentry; 646 u32 query, result = 0, sresult = 0; 647 __be32 error; 648 649 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP); 650 if (error) 651 goto out; 652 653 export = fhp->fh_export; 654 dentry = fhp->fh_dentry; 655 656 if (S_ISREG(dentry->d_inode->i_mode)) 657 map = nfs3_regaccess; 658 else if (S_ISDIR(dentry->d_inode->i_mode)) 659 map = nfs3_diraccess; 660 else 661 map = nfs3_anyaccess; 662 663 664 query = *access; 665 for (; map->access; map++) { 666 if (map->access & query) { 667 __be32 err2; 668 669 sresult |= map->access; 670 671 err2 = nfsd_permission(rqstp, export, dentry, map->how); 672 switch (err2) { 673 case nfs_ok: 674 result |= map->access; 675 break; 676 677 /* the following error codes just mean the access was not allowed, 678 * rather than an error occurred */ 679 case nfserr_rofs: 680 case nfserr_acces: 681 case nfserr_perm: 682 /* simply don't "or" in the access bit. */ 683 break; 684 default: 685 error = err2; 686 goto out; 687 } 688 } 689 } 690 *access = result; 691 if (supported) 692 *supported = sresult; 693 694 out: 695 return error; 696 } 697 #endif /* CONFIG_NFSD_V3 */ 698 699 static int nfsd_open_break_lease(struct inode *inode, int access) 700 { 701 unsigned int mode; 702 703 if (access & NFSD_MAY_NOT_BREAK_LEASE) 704 return 0; 705 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY; 706 return break_lease(inode, mode | O_NONBLOCK); 707 } 708 709 /* 710 * Open an existing file or directory. 711 * The access argument indicates the type of open (read/write/lock) 712 * N.B. After this call fhp needs an fh_put 713 */ 714 __be32 715 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 716 int access, struct file **filp) 717 { 718 struct dentry *dentry; 719 struct inode *inode; 720 int flags = O_RDONLY|O_LARGEFILE; 721 __be32 err; 722 int host_err = 0; 723 724 validate_process_creds(); 725 726 /* 727 * If we get here, then the client has already done an "open", 728 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 729 * in case a chmod has now revoked permission. 730 */ 731 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE); 732 if (err) 733 goto out; 734 735 dentry = fhp->fh_dentry; 736 inode = dentry->d_inode; 737 738 /* Disallow write access to files with the append-only bit set 739 * or any access when mandatory locking enabled 740 */ 741 err = nfserr_perm; 742 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE)) 743 goto out; 744 /* 745 * We must ignore files (but only files) which might have mandatory 746 * locks on them because there is no way to know if the accesser has 747 * the lock. 748 */ 749 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode)) 750 goto out; 751 752 if (!inode->i_fop) 753 goto out; 754 755 host_err = nfsd_open_break_lease(inode, access); 756 if (host_err) /* NOMEM or WOULDBLOCK */ 757 goto out_nfserr; 758 759 if (access & NFSD_MAY_WRITE) { 760 if (access & NFSD_MAY_READ) 761 flags = O_RDWR|O_LARGEFILE; 762 else 763 flags = O_WRONLY|O_LARGEFILE; 764 } 765 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt), 766 flags, current_cred()); 767 if (IS_ERR(*filp)) 768 host_err = PTR_ERR(*filp); 769 else 770 host_err = ima_file_check(*filp, access); 771 out_nfserr: 772 err = nfserrno(host_err); 773 out: 774 validate_process_creds(); 775 return err; 776 } 777 778 /* 779 * Close a file. 780 */ 781 void 782 nfsd_close(struct file *filp) 783 { 784 fput(filp); 785 } 786 787 /* 788 * Obtain the readahead parameters for the file 789 * specified by (dev, ino). 790 */ 791 792 static inline struct raparms * 793 nfsd_get_raparms(dev_t dev, ino_t ino) 794 { 795 struct raparms *ra, **rap, **frap = NULL; 796 int depth = 0; 797 unsigned int hash; 798 struct raparm_hbucket *rab; 799 800 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK; 801 rab = &raparm_hash[hash]; 802 803 spin_lock(&rab->pb_lock); 804 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) { 805 if (ra->p_ino == ino && ra->p_dev == dev) 806 goto found; 807 depth++; 808 if (ra->p_count == 0) 809 frap = rap; 810 } 811 depth = nfsdstats.ra_size; 812 if (!frap) { 813 spin_unlock(&rab->pb_lock); 814 return NULL; 815 } 816 rap = frap; 817 ra = *frap; 818 ra->p_dev = dev; 819 ra->p_ino = ino; 820 ra->p_set = 0; 821 ra->p_hindex = hash; 822 found: 823 if (rap != &rab->pb_head) { 824 *rap = ra->p_next; 825 ra->p_next = rab->pb_head; 826 rab->pb_head = ra; 827 } 828 ra->p_count++; 829 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 830 spin_unlock(&rab->pb_lock); 831 return ra; 832 } 833 834 /* 835 * Grab and keep cached pages associated with a file in the svc_rqst 836 * so that they can be passed to the network sendmsg/sendpage routines 837 * directly. They will be released after the sending has completed. 838 */ 839 static int 840 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 841 struct splice_desc *sd) 842 { 843 struct svc_rqst *rqstp = sd->u.data; 844 struct page **pp = rqstp->rq_respages + rqstp->rq_resused; 845 struct page *page = buf->page; 846 size_t size; 847 848 size = sd->len; 849 850 if (rqstp->rq_res.page_len == 0) { 851 get_page(page); 852 put_page(*pp); 853 *pp = page; 854 rqstp->rq_resused++; 855 rqstp->rq_res.page_base = buf->offset; 856 rqstp->rq_res.page_len = size; 857 } else if (page != pp[-1]) { 858 get_page(page); 859 if (*pp) 860 put_page(*pp); 861 *pp = page; 862 rqstp->rq_resused++; 863 rqstp->rq_res.page_len += size; 864 } else 865 rqstp->rq_res.page_len += size; 866 867 return size; 868 } 869 870 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, 871 struct splice_desc *sd) 872 { 873 return __splice_from_pipe(pipe, sd, nfsd_splice_actor); 874 } 875 876 static __be32 877 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 878 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 879 { 880 mm_segment_t oldfs; 881 __be32 err; 882 int host_err; 883 884 err = nfserr_perm; 885 886 if (file->f_op->splice_read && rqstp->rq_splice_ok) { 887 struct splice_desc sd = { 888 .len = 0, 889 .total_len = *count, 890 .pos = offset, 891 .u.data = rqstp, 892 }; 893 894 rqstp->rq_resused = 1; 895 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); 896 } else { 897 oldfs = get_fs(); 898 set_fs(KERNEL_DS); 899 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 900 set_fs(oldfs); 901 } 902 903 if (host_err >= 0) { 904 nfsdstats.io_read += host_err; 905 *count = host_err; 906 err = 0; 907 fsnotify_access(file); 908 } else 909 err = nfserrno(host_err); 910 return err; 911 } 912 913 static void kill_suid(struct dentry *dentry) 914 { 915 struct iattr ia; 916 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; 917 918 mutex_lock(&dentry->d_inode->i_mutex); 919 notify_change(dentry, &ia); 920 mutex_unlock(&dentry->d_inode->i_mutex); 921 } 922 923 /* 924 * Gathered writes: If another process is currently writing to the file, 925 * there's a high chance this is another nfsd (triggered by a bulk write 926 * from a client's biod). Rather than syncing the file with each write 927 * request, we sleep for 10 msec. 928 * 929 * I don't know if this roughly approximates C. Juszak's idea of 930 * gathered writes, but it's a nice and simple solution (IMHO), and it 931 * seems to work:-) 932 * 933 * Note: we do this only in the NFSv2 case, since v3 and higher have a 934 * better tool (separate unstable writes and commits) for solving this 935 * problem. 936 */ 937 static int wait_for_concurrent_writes(struct file *file) 938 { 939 struct inode *inode = file->f_path.dentry->d_inode; 940 static ino_t last_ino; 941 static dev_t last_dev; 942 int err = 0; 943 944 if (atomic_read(&inode->i_writecount) > 1 945 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 946 dprintk("nfsd: write defer %d\n", task_pid_nr(current)); 947 msleep(10); 948 dprintk("nfsd: write resume %d\n", task_pid_nr(current)); 949 } 950 951 if (inode->i_state & I_DIRTY) { 952 dprintk("nfsd: write sync %d\n", task_pid_nr(current)); 953 err = vfs_fsync(file, 0); 954 } 955 last_ino = inode->i_ino; 956 last_dev = inode->i_sb->s_dev; 957 return err; 958 } 959 960 static __be32 961 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 962 loff_t offset, struct kvec *vec, int vlen, 963 unsigned long *cnt, int *stablep) 964 { 965 struct svc_export *exp; 966 struct dentry *dentry; 967 struct inode *inode; 968 mm_segment_t oldfs; 969 __be32 err = 0; 970 int host_err; 971 int stable = *stablep; 972 int use_wgather; 973 974 dentry = file->f_path.dentry; 975 inode = dentry->d_inode; 976 exp = fhp->fh_export; 977 978 /* 979 * Request sync writes if 980 * - the sync export option has been set, or 981 * - the client requested O_SYNC behavior (NFSv3 feature). 982 * - The file system doesn't support fsync(). 983 * When NFSv2 gathered writes have been configured for this volume, 984 * flushing the data to disk is handled separately below. 985 */ 986 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); 987 988 if (!file->f_op->fsync) {/* COMMIT3 cannot work */ 989 stable = 2; 990 *stablep = 2; /* FILE_SYNC */ 991 } 992 993 if (!EX_ISSYNC(exp)) 994 stable = 0; 995 if (stable && !use_wgather) { 996 spin_lock(&file->f_lock); 997 file->f_flags |= O_SYNC; 998 spin_unlock(&file->f_lock); 999 } 1000 1001 /* Write the data. */ 1002 oldfs = get_fs(); set_fs(KERNEL_DS); 1003 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); 1004 set_fs(oldfs); 1005 if (host_err < 0) 1006 goto out_nfserr; 1007 *cnt = host_err; 1008 nfsdstats.io_write += host_err; 1009 fsnotify_modify(file); 1010 1011 /* clear setuid/setgid flag after write */ 1012 if (inode->i_mode & (S_ISUID | S_ISGID)) 1013 kill_suid(dentry); 1014 1015 if (stable && use_wgather) 1016 host_err = wait_for_concurrent_writes(file); 1017 1018 out_nfserr: 1019 dprintk("nfsd: write complete host_err=%d\n", host_err); 1020 if (host_err >= 0) 1021 err = 0; 1022 else 1023 err = nfserrno(host_err); 1024 return err; 1025 } 1026 1027 /* 1028 * Read data from a file. count must contain the requested read count 1029 * on entry. On return, *count contains the number of bytes actually read. 1030 * N.B. After this call fhp needs an fh_put 1031 */ 1032 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 1033 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 1034 { 1035 struct file *file; 1036 struct inode *inode; 1037 struct raparms *ra; 1038 __be32 err; 1039 1040 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); 1041 if (err) 1042 return err; 1043 1044 inode = file->f_path.dentry->d_inode; 1045 1046 /* Get readahead parameters */ 1047 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 1048 1049 if (ra && ra->p_set) 1050 file->f_ra = ra->p_ra; 1051 1052 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1053 1054 /* Write back readahead params */ 1055 if (ra) { 1056 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex]; 1057 spin_lock(&rab->pb_lock); 1058 ra->p_ra = file->f_ra; 1059 ra->p_set = 1; 1060 ra->p_count--; 1061 spin_unlock(&rab->pb_lock); 1062 } 1063 1064 nfsd_close(file); 1065 return err; 1066 } 1067 1068 /* As above, but use the provided file descriptor. */ 1069 __be32 1070 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1071 loff_t offset, struct kvec *vec, int vlen, 1072 unsigned long *count) 1073 { 1074 __be32 err; 1075 1076 if (file) { 1077 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1078 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE); 1079 if (err) 1080 goto out; 1081 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1082 } else /* Note file may still be NULL in NFSv4 special stateid case: */ 1083 err = nfsd_read(rqstp, fhp, offset, vec, vlen, count); 1084 out: 1085 return err; 1086 } 1087 1088 /* 1089 * Write data to a file. 1090 * The stable flag requests synchronous writes. 1091 * N.B. After this call fhp needs an fh_put 1092 */ 1093 __be32 1094 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1095 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, 1096 int *stablep) 1097 { 1098 __be32 err = 0; 1099 1100 if (file) { 1101 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1102 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE); 1103 if (err) 1104 goto out; 1105 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1106 stablep); 1107 } else { 1108 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); 1109 if (err) 1110 goto out; 1111 1112 if (cnt) 1113 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1114 cnt, stablep); 1115 nfsd_close(file); 1116 } 1117 out: 1118 return err; 1119 } 1120 1121 #ifdef CONFIG_NFSD_V3 1122 /* 1123 * Commit all pending writes to stable storage. 1124 * 1125 * Note: we only guarantee that data that lies within the range specified 1126 * by the 'offset' and 'count' parameters will be synced. 1127 * 1128 * Unfortunately we cannot lock the file to make sure we return full WCC 1129 * data to the client, as locking happens lower down in the filesystem. 1130 */ 1131 __be32 1132 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1133 loff_t offset, unsigned long count) 1134 { 1135 struct file *file; 1136 loff_t end = LLONG_MAX; 1137 __be32 err = nfserr_inval; 1138 1139 if (offset < 0) 1140 goto out; 1141 if (count != 0) { 1142 end = offset + (loff_t)count - 1; 1143 if (end < offset) 1144 goto out; 1145 } 1146 1147 err = nfsd_open(rqstp, fhp, S_IFREG, 1148 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file); 1149 if (err) 1150 goto out; 1151 if (EX_ISSYNC(fhp->fh_export)) { 1152 int err2 = vfs_fsync_range(file, offset, end, 0); 1153 1154 if (err2 != -EINVAL) 1155 err = nfserrno(err2); 1156 else 1157 err = nfserr_notsupp; 1158 } 1159 1160 nfsd_close(file); 1161 out: 1162 return err; 1163 } 1164 #endif /* CONFIG_NFSD_V3 */ 1165 1166 static __be32 1167 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp, 1168 struct iattr *iap) 1169 { 1170 /* 1171 * Mode has already been set earlier in create: 1172 */ 1173 iap->ia_valid &= ~ATTR_MODE; 1174 /* 1175 * Setting uid/gid works only for root. Irix appears to 1176 * send along the gid on create when it tries to implement 1177 * setgid directories via NFS: 1178 */ 1179 if (current_fsuid() != 0) 1180 iap->ia_valid &= ~(ATTR_UID|ATTR_GID); 1181 if (iap->ia_valid) 1182 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1183 return 0; 1184 } 1185 1186 /* HPUX client sometimes creates a file in mode 000, and sets size to 0. 1187 * setting size to 0 may fail for some specific file systems by the permission 1188 * checking which requires WRITE permission but the mode is 000. 1189 * we ignore the resizing(to 0) on the just new created file, since the size is 1190 * 0 after file created. 1191 * 1192 * call this only after vfs_create() is called. 1193 * */ 1194 static void 1195 nfsd_check_ignore_resizing(struct iattr *iap) 1196 { 1197 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) 1198 iap->ia_valid &= ~ATTR_SIZE; 1199 } 1200 1201 /* 1202 * Create a file (regular, directory, device, fifo); UNIX sockets 1203 * not yet implemented. 1204 * If the response fh has been verified, the parent directory should 1205 * already be locked. Note that the parent directory is left locked. 1206 * 1207 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1208 */ 1209 __be32 1210 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1211 char *fname, int flen, struct iattr *iap, 1212 int type, dev_t rdev, struct svc_fh *resfhp) 1213 { 1214 struct dentry *dentry, *dchild = NULL; 1215 struct inode *dirp; 1216 __be32 err; 1217 __be32 err2; 1218 int host_err; 1219 1220 err = nfserr_perm; 1221 if (!flen) 1222 goto out; 1223 err = nfserr_exist; 1224 if (isdotent(fname, flen)) 1225 goto out; 1226 1227 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1228 if (err) 1229 goto out; 1230 1231 dentry = fhp->fh_dentry; 1232 dirp = dentry->d_inode; 1233 1234 err = nfserr_notdir; 1235 if (!dirp->i_op->lookup) 1236 goto out; 1237 /* 1238 * Check whether the response file handle has been verified yet. 1239 * If it has, the parent directory should already be locked. 1240 */ 1241 if (!resfhp->fh_dentry) { 1242 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1243 fh_lock_nested(fhp, I_MUTEX_PARENT); 1244 dchild = lookup_one_len(fname, dentry, flen); 1245 host_err = PTR_ERR(dchild); 1246 if (IS_ERR(dchild)) 1247 goto out_nfserr; 1248 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1249 if (err) 1250 goto out; 1251 } else { 1252 /* called from nfsd_proc_create */ 1253 dchild = dget(resfhp->fh_dentry); 1254 if (!fhp->fh_locked) { 1255 /* not actually possible */ 1256 printk(KERN_ERR 1257 "nfsd_create: parent %s/%s not locked!\n", 1258 dentry->d_parent->d_name.name, 1259 dentry->d_name.name); 1260 err = nfserr_io; 1261 goto out; 1262 } 1263 } 1264 /* 1265 * Make sure the child dentry is still negative ... 1266 */ 1267 err = nfserr_exist; 1268 if (dchild->d_inode) { 1269 dprintk("nfsd_create: dentry %s/%s not negative!\n", 1270 dentry->d_name.name, dchild->d_name.name); 1271 goto out; 1272 } 1273 1274 if (!(iap->ia_valid & ATTR_MODE)) 1275 iap->ia_mode = 0; 1276 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1277 1278 err = nfserr_inval; 1279 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) { 1280 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", 1281 type); 1282 goto out; 1283 } 1284 1285 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1286 if (host_err) 1287 goto out_nfserr; 1288 1289 /* 1290 * Get the dir op function pointer. 1291 */ 1292 err = 0; 1293 switch (type) { 1294 case S_IFREG: 1295 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1296 if (!host_err) 1297 nfsd_check_ignore_resizing(iap); 1298 break; 1299 case S_IFDIR: 1300 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1301 break; 1302 case S_IFCHR: 1303 case S_IFBLK: 1304 case S_IFIFO: 1305 case S_IFSOCK: 1306 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1307 break; 1308 } 1309 if (host_err < 0) { 1310 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1311 goto out_nfserr; 1312 } 1313 1314 err = nfsd_create_setattr(rqstp, resfhp, iap); 1315 1316 /* 1317 * nfsd_setattr already committed the child. Transactional filesystems 1318 * had a chance to commit changes for both parent and child 1319 * simultaneously making the following commit_metadata a noop. 1320 */ 1321 err2 = nfserrno(commit_metadata(fhp)); 1322 if (err2) 1323 err = err2; 1324 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1325 /* 1326 * Update the file handle to get the new inode info. 1327 */ 1328 if (!err) 1329 err = fh_update(resfhp); 1330 out: 1331 if (dchild && !IS_ERR(dchild)) 1332 dput(dchild); 1333 return err; 1334 1335 out_nfserr: 1336 err = nfserrno(host_err); 1337 goto out; 1338 } 1339 1340 #ifdef CONFIG_NFSD_V3 1341 1342 static inline int nfsd_create_is_exclusive(int createmode) 1343 { 1344 return createmode == NFS3_CREATE_EXCLUSIVE 1345 || createmode == NFS4_CREATE_EXCLUSIVE4_1; 1346 } 1347 1348 /* 1349 * NFSv3 and NFSv4 version of nfsd_create 1350 */ 1351 __be32 1352 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1353 char *fname, int flen, struct iattr *iap, 1354 struct svc_fh *resfhp, int createmode, u32 *verifier, 1355 int *truncp, int *created) 1356 { 1357 struct dentry *dentry, *dchild = NULL; 1358 struct inode *dirp; 1359 __be32 err; 1360 int host_err; 1361 __u32 v_mtime=0, v_atime=0; 1362 1363 err = nfserr_perm; 1364 if (!flen) 1365 goto out; 1366 err = nfserr_exist; 1367 if (isdotent(fname, flen)) 1368 goto out; 1369 if (!(iap->ia_valid & ATTR_MODE)) 1370 iap->ia_mode = 0; 1371 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); 1372 if (err) 1373 goto out; 1374 1375 dentry = fhp->fh_dentry; 1376 dirp = dentry->d_inode; 1377 1378 /* Get all the sanity checks out of the way before 1379 * we lock the parent. */ 1380 err = nfserr_notdir; 1381 if (!dirp->i_op->lookup) 1382 goto out; 1383 fh_lock_nested(fhp, I_MUTEX_PARENT); 1384 1385 /* 1386 * Compose the response file handle. 1387 */ 1388 dchild = lookup_one_len(fname, dentry, flen); 1389 host_err = PTR_ERR(dchild); 1390 if (IS_ERR(dchild)) 1391 goto out_nfserr; 1392 1393 /* If file doesn't exist, check for permissions to create one */ 1394 if (!dchild->d_inode) { 1395 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1396 if (err) 1397 goto out; 1398 } 1399 1400 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1401 if (err) 1402 goto out; 1403 1404 if (nfsd_create_is_exclusive(createmode)) { 1405 /* solaris7 gets confused (bugid 4218508) if these have 1406 * the high bit set, so just clear the high bits. If this is 1407 * ever changed to use different attrs for storing the 1408 * verifier, then do_open_lookup() will also need to be fixed 1409 * accordingly. 1410 */ 1411 v_mtime = verifier[0]&0x7fffffff; 1412 v_atime = verifier[1]&0x7fffffff; 1413 } 1414 1415 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1416 if (host_err) 1417 goto out_nfserr; 1418 if (dchild->d_inode) { 1419 err = 0; 1420 1421 switch (createmode) { 1422 case NFS3_CREATE_UNCHECKED: 1423 if (! S_ISREG(dchild->d_inode->i_mode)) 1424 err = nfserr_exist; 1425 else if (truncp) { 1426 /* in nfsv4, we need to treat this case a little 1427 * differently. we don't want to truncate the 1428 * file now; this would be wrong if the OPEN 1429 * fails for some other reason. furthermore, 1430 * if the size is nonzero, we should ignore it 1431 * according to spec! 1432 */ 1433 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1434 } 1435 else { 1436 iap->ia_valid &= ATTR_SIZE; 1437 goto set_attr; 1438 } 1439 break; 1440 case NFS3_CREATE_EXCLUSIVE: 1441 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1442 && dchild->d_inode->i_atime.tv_sec == v_atime 1443 && dchild->d_inode->i_size == 0 ) 1444 break; 1445 case NFS4_CREATE_EXCLUSIVE4_1: 1446 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1447 && dchild->d_inode->i_atime.tv_sec == v_atime 1448 && dchild->d_inode->i_size == 0 ) 1449 goto set_attr; 1450 /* fallthru */ 1451 case NFS3_CREATE_GUARDED: 1452 err = nfserr_exist; 1453 } 1454 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1455 goto out; 1456 } 1457 1458 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1459 if (host_err < 0) { 1460 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1461 goto out_nfserr; 1462 } 1463 if (created) 1464 *created = 1; 1465 1466 nfsd_check_ignore_resizing(iap); 1467 1468 if (nfsd_create_is_exclusive(createmode)) { 1469 /* Cram the verifier into atime/mtime */ 1470 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1471 | ATTR_MTIME_SET|ATTR_ATIME_SET; 1472 /* XXX someone who knows this better please fix it for nsec */ 1473 iap->ia_mtime.tv_sec = v_mtime; 1474 iap->ia_atime.tv_sec = v_atime; 1475 iap->ia_mtime.tv_nsec = 0; 1476 iap->ia_atime.tv_nsec = 0; 1477 } 1478 1479 set_attr: 1480 err = nfsd_create_setattr(rqstp, resfhp, iap); 1481 1482 /* 1483 * nfsd_setattr already committed the child (and possibly also the parent). 1484 */ 1485 if (!err) 1486 err = nfserrno(commit_metadata(fhp)); 1487 1488 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1489 /* 1490 * Update the filehandle to get the new inode info. 1491 */ 1492 if (!err) 1493 err = fh_update(resfhp); 1494 1495 out: 1496 fh_unlock(fhp); 1497 if (dchild && !IS_ERR(dchild)) 1498 dput(dchild); 1499 return err; 1500 1501 out_nfserr: 1502 err = nfserrno(host_err); 1503 goto out; 1504 } 1505 #endif /* CONFIG_NFSD_V3 */ 1506 1507 /* 1508 * Read a symlink. On entry, *lenp must contain the maximum path length that 1509 * fits into the buffer. On return, it contains the true length. 1510 * N.B. After this call fhp needs an fh_put 1511 */ 1512 __be32 1513 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1514 { 1515 struct dentry *dentry; 1516 struct inode *inode; 1517 mm_segment_t oldfs; 1518 __be32 err; 1519 int host_err; 1520 1521 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); 1522 if (err) 1523 goto out; 1524 1525 dentry = fhp->fh_dentry; 1526 inode = dentry->d_inode; 1527 1528 err = nfserr_inval; 1529 if (!inode->i_op->readlink) 1530 goto out; 1531 1532 touch_atime(fhp->fh_export->ex_path.mnt, dentry); 1533 /* N.B. Why does this call need a get_fs()?? 1534 * Remove the set_fs and watch the fireworks:-) --okir 1535 */ 1536 1537 oldfs = get_fs(); set_fs(KERNEL_DS); 1538 host_err = inode->i_op->readlink(dentry, buf, *lenp); 1539 set_fs(oldfs); 1540 1541 if (host_err < 0) 1542 goto out_nfserr; 1543 *lenp = host_err; 1544 err = 0; 1545 out: 1546 return err; 1547 1548 out_nfserr: 1549 err = nfserrno(host_err); 1550 goto out; 1551 } 1552 1553 /* 1554 * Create a symlink and look up its inode 1555 * N.B. After this call _both_ fhp and resfhp need an fh_put 1556 */ 1557 __be32 1558 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1559 char *fname, int flen, 1560 char *path, int plen, 1561 struct svc_fh *resfhp, 1562 struct iattr *iap) 1563 { 1564 struct dentry *dentry, *dnew; 1565 __be32 err, cerr; 1566 int host_err; 1567 1568 err = nfserr_noent; 1569 if (!flen || !plen) 1570 goto out; 1571 err = nfserr_exist; 1572 if (isdotent(fname, flen)) 1573 goto out; 1574 1575 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1576 if (err) 1577 goto out; 1578 fh_lock(fhp); 1579 dentry = fhp->fh_dentry; 1580 dnew = lookup_one_len(fname, dentry, flen); 1581 host_err = PTR_ERR(dnew); 1582 if (IS_ERR(dnew)) 1583 goto out_nfserr; 1584 1585 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1586 if (host_err) 1587 goto out_nfserr; 1588 1589 if (unlikely(path[plen] != 0)) { 1590 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1591 if (path_alloced == NULL) 1592 host_err = -ENOMEM; 1593 else { 1594 strncpy(path_alloced, path, plen); 1595 path_alloced[plen] = 0; 1596 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced); 1597 kfree(path_alloced); 1598 } 1599 } else 1600 host_err = vfs_symlink(dentry->d_inode, dnew, path); 1601 err = nfserrno(host_err); 1602 if (!err) 1603 err = nfserrno(commit_metadata(fhp)); 1604 fh_unlock(fhp); 1605 1606 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1607 1608 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1609 dput(dnew); 1610 if (err==0) err = cerr; 1611 out: 1612 return err; 1613 1614 out_nfserr: 1615 err = nfserrno(host_err); 1616 goto out; 1617 } 1618 1619 /* 1620 * Create a hardlink 1621 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1622 */ 1623 __be32 1624 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1625 char *name, int len, struct svc_fh *tfhp) 1626 { 1627 struct dentry *ddir, *dnew, *dold; 1628 struct inode *dirp; 1629 __be32 err; 1630 int host_err; 1631 1632 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); 1633 if (err) 1634 goto out; 1635 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP); 1636 if (err) 1637 goto out; 1638 err = nfserr_isdir; 1639 if (S_ISDIR(tfhp->fh_dentry->d_inode->i_mode)) 1640 goto out; 1641 err = nfserr_perm; 1642 if (!len) 1643 goto out; 1644 err = nfserr_exist; 1645 if (isdotent(name, len)) 1646 goto out; 1647 1648 fh_lock_nested(ffhp, I_MUTEX_PARENT); 1649 ddir = ffhp->fh_dentry; 1650 dirp = ddir->d_inode; 1651 1652 dnew = lookup_one_len(name, ddir, len); 1653 host_err = PTR_ERR(dnew); 1654 if (IS_ERR(dnew)) 1655 goto out_nfserr; 1656 1657 dold = tfhp->fh_dentry; 1658 1659 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt); 1660 if (host_err) { 1661 err = nfserrno(host_err); 1662 goto out_dput; 1663 } 1664 err = nfserr_noent; 1665 if (!dold->d_inode) 1666 goto out_drop_write; 1667 host_err = nfsd_break_lease(dold->d_inode); 1668 if (host_err) { 1669 err = nfserrno(host_err); 1670 goto out_drop_write; 1671 } 1672 host_err = vfs_link(dold, dirp, dnew); 1673 if (!host_err) { 1674 err = nfserrno(commit_metadata(ffhp)); 1675 if (!err) 1676 err = nfserrno(commit_metadata(tfhp)); 1677 } else { 1678 if (host_err == -EXDEV && rqstp->rq_vers == 2) 1679 err = nfserr_acces; 1680 else 1681 err = nfserrno(host_err); 1682 } 1683 out_drop_write: 1684 mnt_drop_write(tfhp->fh_export->ex_path.mnt); 1685 out_dput: 1686 dput(dnew); 1687 out_unlock: 1688 fh_unlock(ffhp); 1689 out: 1690 return err; 1691 1692 out_nfserr: 1693 err = nfserrno(host_err); 1694 goto out_unlock; 1695 } 1696 1697 /* 1698 * Rename a file 1699 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1700 */ 1701 __be32 1702 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1703 struct svc_fh *tfhp, char *tname, int tlen) 1704 { 1705 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1706 struct inode *fdir, *tdir; 1707 __be32 err; 1708 int host_err; 1709 1710 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); 1711 if (err) 1712 goto out; 1713 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE); 1714 if (err) 1715 goto out; 1716 1717 fdentry = ffhp->fh_dentry; 1718 fdir = fdentry->d_inode; 1719 1720 tdentry = tfhp->fh_dentry; 1721 tdir = tdentry->d_inode; 1722 1723 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; 1724 if (ffhp->fh_export != tfhp->fh_export) 1725 goto out; 1726 1727 err = nfserr_perm; 1728 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1729 goto out; 1730 1731 /* cannot use fh_lock as we need deadlock protective ordering 1732 * so do it by hand */ 1733 trap = lock_rename(tdentry, fdentry); 1734 ffhp->fh_locked = tfhp->fh_locked = 1; 1735 fill_pre_wcc(ffhp); 1736 fill_pre_wcc(tfhp); 1737 1738 odentry = lookup_one_len(fname, fdentry, flen); 1739 host_err = PTR_ERR(odentry); 1740 if (IS_ERR(odentry)) 1741 goto out_nfserr; 1742 1743 host_err = -ENOENT; 1744 if (!odentry->d_inode) 1745 goto out_dput_old; 1746 host_err = -EINVAL; 1747 if (odentry == trap) 1748 goto out_dput_old; 1749 1750 ndentry = lookup_one_len(tname, tdentry, tlen); 1751 host_err = PTR_ERR(ndentry); 1752 if (IS_ERR(ndentry)) 1753 goto out_dput_old; 1754 host_err = -ENOTEMPTY; 1755 if (ndentry == trap) 1756 goto out_dput_new; 1757 1758 host_err = -EXDEV; 1759 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) 1760 goto out_dput_new; 1761 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt); 1762 if (host_err) 1763 goto out_dput_new; 1764 1765 host_err = nfsd_break_lease(odentry->d_inode); 1766 if (host_err) 1767 goto out_drop_write; 1768 if (ndentry->d_inode) { 1769 host_err = nfsd_break_lease(ndentry->d_inode); 1770 if (host_err) 1771 goto out_drop_write; 1772 } 1773 host_err = vfs_rename(fdir, odentry, tdir, ndentry); 1774 if (!host_err) { 1775 host_err = commit_metadata(tfhp); 1776 if (!host_err) 1777 host_err = commit_metadata(ffhp); 1778 } 1779 out_drop_write: 1780 mnt_drop_write(ffhp->fh_export->ex_path.mnt); 1781 out_dput_new: 1782 dput(ndentry); 1783 out_dput_old: 1784 dput(odentry); 1785 out_nfserr: 1786 err = nfserrno(host_err); 1787 1788 /* we cannot reply on fh_unlock on the two filehandles, 1789 * as that would do the wrong thing if the two directories 1790 * were the same, so again we do it by hand 1791 */ 1792 fill_post_wcc(ffhp); 1793 fill_post_wcc(tfhp); 1794 unlock_rename(tdentry, fdentry); 1795 ffhp->fh_locked = tfhp->fh_locked = 0; 1796 1797 out: 1798 return err; 1799 } 1800 1801 /* 1802 * Unlink a file or directory 1803 * N.B. After this call fhp needs an fh_put 1804 */ 1805 __be32 1806 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1807 char *fname, int flen) 1808 { 1809 struct dentry *dentry, *rdentry; 1810 struct inode *dirp; 1811 __be32 err; 1812 int host_err; 1813 1814 err = nfserr_acces; 1815 if (!flen || isdotent(fname, flen)) 1816 goto out; 1817 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); 1818 if (err) 1819 goto out; 1820 1821 fh_lock_nested(fhp, I_MUTEX_PARENT); 1822 dentry = fhp->fh_dentry; 1823 dirp = dentry->d_inode; 1824 1825 rdentry = lookup_one_len(fname, dentry, flen); 1826 host_err = PTR_ERR(rdentry); 1827 if (IS_ERR(rdentry)) 1828 goto out_nfserr; 1829 1830 if (!rdentry->d_inode) { 1831 dput(rdentry); 1832 err = nfserr_noent; 1833 goto out; 1834 } 1835 1836 if (!type) 1837 type = rdentry->d_inode->i_mode & S_IFMT; 1838 1839 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1840 if (host_err) 1841 goto out_put; 1842 1843 host_err = nfsd_break_lease(rdentry->d_inode); 1844 if (host_err) 1845 goto out_drop_write; 1846 if (type != S_IFDIR) 1847 host_err = vfs_unlink(dirp, rdentry); 1848 else 1849 host_err = vfs_rmdir(dirp, rdentry); 1850 if (!host_err) 1851 host_err = commit_metadata(fhp); 1852 out_drop_write: 1853 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1854 out_put: 1855 dput(rdentry); 1856 1857 out_nfserr: 1858 err = nfserrno(host_err); 1859 out: 1860 return err; 1861 } 1862 1863 /* 1864 * We do this buffering because we must not call back into the file 1865 * system's ->lookup() method from the filldir callback. That may well 1866 * deadlock a number of file systems. 1867 * 1868 * This is based heavily on the implementation of same in XFS. 1869 */ 1870 struct buffered_dirent { 1871 u64 ino; 1872 loff_t offset; 1873 int namlen; 1874 unsigned int d_type; 1875 char name[]; 1876 }; 1877 1878 struct readdir_data { 1879 char *dirent; 1880 size_t used; 1881 int full; 1882 }; 1883 1884 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, 1885 loff_t offset, u64 ino, unsigned int d_type) 1886 { 1887 struct readdir_data *buf = __buf; 1888 struct buffered_dirent *de = (void *)(buf->dirent + buf->used); 1889 unsigned int reclen; 1890 1891 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); 1892 if (buf->used + reclen > PAGE_SIZE) { 1893 buf->full = 1; 1894 return -EINVAL; 1895 } 1896 1897 de->namlen = namlen; 1898 de->offset = offset; 1899 de->ino = ino; 1900 de->d_type = d_type; 1901 memcpy(de->name, name, namlen); 1902 buf->used += reclen; 1903 1904 return 0; 1905 } 1906 1907 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, 1908 struct readdir_cd *cdp, loff_t *offsetp) 1909 { 1910 struct readdir_data buf; 1911 struct buffered_dirent *de; 1912 int host_err; 1913 int size; 1914 loff_t offset; 1915 1916 buf.dirent = (void *)__get_free_page(GFP_KERNEL); 1917 if (!buf.dirent) 1918 return nfserrno(-ENOMEM); 1919 1920 offset = *offsetp; 1921 1922 while (1) { 1923 struct inode *dir_inode = file->f_path.dentry->d_inode; 1924 unsigned int reclen; 1925 1926 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1927 buf.used = 0; 1928 buf.full = 0; 1929 1930 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf); 1931 if (buf.full) 1932 host_err = 0; 1933 1934 if (host_err < 0) 1935 break; 1936 1937 size = buf.used; 1938 1939 if (!size) 1940 break; 1941 1942 /* 1943 * Various filldir functions may end up calling back into 1944 * lookup_one_len() and the file system's ->lookup() method. 1945 * These expect i_mutex to be held, as it would within readdir. 1946 */ 1947 host_err = mutex_lock_killable(&dir_inode->i_mutex); 1948 if (host_err) 1949 break; 1950 1951 de = (struct buffered_dirent *)buf.dirent; 1952 while (size > 0) { 1953 offset = de->offset; 1954 1955 if (func(cdp, de->name, de->namlen, de->offset, 1956 de->ino, de->d_type)) 1957 break; 1958 1959 if (cdp->err != nfs_ok) 1960 break; 1961 1962 reclen = ALIGN(sizeof(*de) + de->namlen, 1963 sizeof(u64)); 1964 size -= reclen; 1965 de = (struct buffered_dirent *)((char *)de + reclen); 1966 } 1967 mutex_unlock(&dir_inode->i_mutex); 1968 if (size > 0) /* We bailed out early */ 1969 break; 1970 1971 offset = vfs_llseek(file, 0, SEEK_CUR); 1972 } 1973 1974 free_page((unsigned long)(buf.dirent)); 1975 1976 if (host_err) 1977 return nfserrno(host_err); 1978 1979 *offsetp = offset; 1980 return cdp->err; 1981 } 1982 1983 /* 1984 * Read entries from a directory. 1985 * The NFSv3/4 verifier we ignore for now. 1986 */ 1987 __be32 1988 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 1989 struct readdir_cd *cdp, filldir_t func) 1990 { 1991 __be32 err; 1992 struct file *file; 1993 loff_t offset = *offsetp; 1994 1995 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file); 1996 if (err) 1997 goto out; 1998 1999 offset = vfs_llseek(file, offset, 0); 2000 if (offset < 0) { 2001 err = nfserrno((int)offset); 2002 goto out_close; 2003 } 2004 2005 err = nfsd_buffered_readdir(file, func, cdp, offsetp); 2006 2007 if (err == nfserr_eof || err == nfserr_toosmall) 2008 err = nfs_ok; /* can still be found in ->err */ 2009 out_close: 2010 nfsd_close(file); 2011 out: 2012 return err; 2013 } 2014 2015 /* 2016 * Get file system stats 2017 * N.B. After this call fhp needs an fh_put 2018 */ 2019 __be32 2020 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) 2021 { 2022 __be32 err; 2023 2024 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); 2025 if (!err) { 2026 struct path path = { 2027 .mnt = fhp->fh_export->ex_path.mnt, 2028 .dentry = fhp->fh_dentry, 2029 }; 2030 if (vfs_statfs(&path, stat)) 2031 err = nfserr_io; 2032 } 2033 return err; 2034 } 2035 2036 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) 2037 { 2038 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; 2039 } 2040 2041 /* 2042 * Check for a user's access permissions to this inode. 2043 */ 2044 __be32 2045 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, 2046 struct dentry *dentry, int acc) 2047 { 2048 struct inode *inode = dentry->d_inode; 2049 int err; 2050 2051 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP) 2052 return 0; 2053 #if 0 2054 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 2055 acc, 2056 (acc & NFSD_MAY_READ)? " read" : "", 2057 (acc & NFSD_MAY_WRITE)? " write" : "", 2058 (acc & NFSD_MAY_EXEC)? " exec" : "", 2059 (acc & NFSD_MAY_SATTR)? " sattr" : "", 2060 (acc & NFSD_MAY_TRUNC)? " trunc" : "", 2061 (acc & NFSD_MAY_LOCK)? " lock" : "", 2062 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", 2063 inode->i_mode, 2064 IS_IMMUTABLE(inode)? " immut" : "", 2065 IS_APPEND(inode)? " append" : "", 2066 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); 2067 dprintk(" owner %d/%d user %d/%d\n", 2068 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); 2069 #endif 2070 2071 /* Normally we reject any write/sattr etc access on a read-only file 2072 * system. But if it is IRIX doing check on write-access for a 2073 * device special file, we ignore rofs. 2074 */ 2075 if (!(acc & NFSD_MAY_LOCAL_ACCESS)) 2076 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { 2077 if (exp_rdonly(rqstp, exp) || 2078 __mnt_is_readonly(exp->ex_path.mnt)) 2079 return nfserr_rofs; 2080 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) 2081 return nfserr_perm; 2082 } 2083 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) 2084 return nfserr_perm; 2085 2086 if (acc & NFSD_MAY_LOCK) { 2087 /* If we cannot rely on authentication in NLM requests, 2088 * just allow locks, otherwise require read permission, or 2089 * ownership 2090 */ 2091 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 2092 return 0; 2093 else 2094 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE; 2095 } 2096 /* 2097 * The file owner always gets access permission for accesses that 2098 * would normally be checked at open time. This is to make 2099 * file access work even when the client has done a fchmod(fd, 0). 2100 * 2101 * However, `cp foo bar' should fail nevertheless when bar is 2102 * readonly. A sensible way to do this might be to reject all 2103 * attempts to truncate a read-only file, because a creat() call 2104 * always implies file truncation. 2105 * ... but this isn't really fair. A process may reasonably call 2106 * ftruncate on an open file descriptor on a file with perm 000. 2107 * We must trust the client to do permission checking - using "ACCESS" 2108 * with NFSv3. 2109 */ 2110 if ((acc & NFSD_MAY_OWNER_OVERRIDE) && 2111 inode->i_uid == current_fsuid()) 2112 return 0; 2113 2114 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ 2115 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); 2116 2117 /* Allow read access to binaries even when mode 111 */ 2118 if (err == -EACCES && S_ISREG(inode->i_mode) && 2119 acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE)) 2120 err = inode_permission(inode, MAY_EXEC); 2121 2122 return err? nfserrno(err) : 0; 2123 } 2124 2125 void 2126 nfsd_racache_shutdown(void) 2127 { 2128 struct raparms *raparm, *last_raparm; 2129 unsigned int i; 2130 2131 dprintk("nfsd: freeing readahead buffers.\n"); 2132 2133 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2134 raparm = raparm_hash[i].pb_head; 2135 while(raparm) { 2136 last_raparm = raparm; 2137 raparm = raparm->p_next; 2138 kfree(last_raparm); 2139 } 2140 raparm_hash[i].pb_head = NULL; 2141 } 2142 } 2143 /* 2144 * Initialize readahead param cache 2145 */ 2146 int 2147 nfsd_racache_init(int cache_size) 2148 { 2149 int i; 2150 int j = 0; 2151 int nperbucket; 2152 struct raparms **raparm = NULL; 2153 2154 2155 if (raparm_hash[0].pb_head) 2156 return 0; 2157 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE); 2158 if (nperbucket < 2) 2159 nperbucket = 2; 2160 cache_size = nperbucket * RAPARM_HASH_SIZE; 2161 2162 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); 2163 2164 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2165 spin_lock_init(&raparm_hash[i].pb_lock); 2166 2167 raparm = &raparm_hash[i].pb_head; 2168 for (j = 0; j < nperbucket; j++) { 2169 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL); 2170 if (!*raparm) 2171 goto out_nomem; 2172 raparm = &(*raparm)->p_next; 2173 } 2174 *raparm = NULL; 2175 } 2176 2177 nfsdstats.ra_size = cache_size; 2178 return 0; 2179 2180 out_nomem: 2181 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n"); 2182 nfsd_racache_shutdown(); 2183 return -ENOMEM; 2184 } 2185 2186 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 2187 struct posix_acl * 2188 nfsd_get_posix_acl(struct svc_fh *fhp, int type) 2189 { 2190 struct inode *inode = fhp->fh_dentry->d_inode; 2191 char *name; 2192 void *value = NULL; 2193 ssize_t size; 2194 struct posix_acl *acl; 2195 2196 if (!IS_POSIXACL(inode)) 2197 return ERR_PTR(-EOPNOTSUPP); 2198 2199 switch (type) { 2200 case ACL_TYPE_ACCESS: 2201 name = POSIX_ACL_XATTR_ACCESS; 2202 break; 2203 case ACL_TYPE_DEFAULT: 2204 name = POSIX_ACL_XATTR_DEFAULT; 2205 break; 2206 default: 2207 return ERR_PTR(-EOPNOTSUPP); 2208 } 2209 2210 size = nfsd_getxattr(fhp->fh_dentry, name, &value); 2211 if (size < 0) 2212 return ERR_PTR(size); 2213 2214 acl = posix_acl_from_xattr(value, size); 2215 kfree(value); 2216 return acl; 2217 } 2218 2219 int 2220 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) 2221 { 2222 struct inode *inode = fhp->fh_dentry->d_inode; 2223 char *name; 2224 void *value = NULL; 2225 size_t size; 2226 int error; 2227 2228 if (!IS_POSIXACL(inode) || 2229 !inode->i_op->setxattr || !inode->i_op->removexattr) 2230 return -EOPNOTSUPP; 2231 switch(type) { 2232 case ACL_TYPE_ACCESS: 2233 name = POSIX_ACL_XATTR_ACCESS; 2234 break; 2235 case ACL_TYPE_DEFAULT: 2236 name = POSIX_ACL_XATTR_DEFAULT; 2237 break; 2238 default: 2239 return -EOPNOTSUPP; 2240 } 2241 2242 if (acl && acl->a_count) { 2243 size = posix_acl_xattr_size(acl->a_count); 2244 value = kmalloc(size, GFP_KERNEL); 2245 if (!value) 2246 return -ENOMEM; 2247 error = posix_acl_to_xattr(acl, value, size); 2248 if (error < 0) 2249 goto getout; 2250 size = error; 2251 } else 2252 size = 0; 2253 2254 error = mnt_want_write(fhp->fh_export->ex_path.mnt); 2255 if (error) 2256 goto getout; 2257 if (size) 2258 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); 2259 else { 2260 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) 2261 error = 0; 2262 else { 2263 error = vfs_removexattr(fhp->fh_dentry, name); 2264 if (error == -ENODATA) 2265 error = 0; 2266 } 2267 } 2268 mnt_drop_write(fhp->fh_export->ex_path.mnt); 2269 2270 getout: 2271 kfree(value); 2272 return error; 2273 } 2274 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 2275