1 #define MSNFS /* HACK HACK */ 2 /* 3 * File operations used by nfsd. Some of these have been ripped from 4 * other parts of the kernel because they weren't exported, others 5 * are partial duplicates with added or changed functionality. 6 * 7 * Note that several functions dget() the dentry upon which they want 8 * to act, most notably those that create directory entries. Response 9 * dentry's are dput()'d if necessary in the release callback. 10 * So if you notice code paths that apparently fail to dput() the 11 * dentry, don't worry--they have been taken care of. 12 * 13 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de> 14 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp> 15 */ 16 17 #include <linux/fs.h> 18 #include <linux/file.h> 19 #include <linux/splice.h> 20 #include <linux/fcntl.h> 21 #include <linux/namei.h> 22 #include <linux/delay.h> 23 #include <linux/fsnotify.h> 24 #include <linux/posix_acl_xattr.h> 25 #include <linux/xattr.h> 26 #include <linux/jhash.h> 27 #include <linux/ima.h> 28 #include <linux/slab.h> 29 #include <asm/uaccess.h> 30 #include <linux/exportfs.h> 31 #include <linux/writeback.h> 32 33 #ifdef CONFIG_NFSD_V3 34 #include "xdr3.h" 35 #endif /* CONFIG_NFSD_V3 */ 36 37 #ifdef CONFIG_NFSD_V4 38 #include <linux/nfs4_acl.h> 39 #include <linux/nfsd_idmap.h> 40 #endif /* CONFIG_NFSD_V4 */ 41 42 #include "nfsd.h" 43 #include "vfs.h" 44 45 #define NFSDDBG_FACILITY NFSDDBG_FILEOP 46 47 48 /* 49 * This is a cache of readahead params that help us choose the proper 50 * readahead strategy. Initially, we set all readahead parameters to 0 51 * and let the VFS handle things. 52 * If you increase the number of cached files very much, you'll need to 53 * add a hash table here. 54 */ 55 struct raparms { 56 struct raparms *p_next; 57 unsigned int p_count; 58 ino_t p_ino; 59 dev_t p_dev; 60 int p_set; 61 struct file_ra_state p_ra; 62 unsigned int p_hindex; 63 }; 64 65 struct raparm_hbucket { 66 struct raparms *pb_head; 67 spinlock_t pb_lock; 68 } ____cacheline_aligned_in_smp; 69 70 #define RAPARM_HASH_BITS 4 71 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS) 72 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1) 73 static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE]; 74 75 /* 76 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 77 * a mount point. 78 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged, 79 * or nfs_ok having possibly changed *dpp and *expp 80 */ 81 int 82 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 83 struct svc_export **expp) 84 { 85 struct svc_export *exp = *expp, *exp2 = NULL; 86 struct dentry *dentry = *dpp; 87 struct path path = {.mnt = mntget(exp->ex_path.mnt), 88 .dentry = dget(dentry)}; 89 int err = 0; 90 91 while (d_mountpoint(path.dentry) && follow_down(&path)) 92 ; 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 __be32 err; 185 int host_err; 186 187 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); 188 189 /* Obtain dentry and export. */ 190 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); 191 if (err) 192 return err; 193 194 dparent = fhp->fh_dentry; 195 exp = fhp->fh_export; 196 exp_get(exp); 197 198 /* Lookup the name, but don't follow links */ 199 if (isdotent(name, len)) { 200 if (len==1) 201 dentry = dget(dparent); 202 else if (dparent != exp->ex_path.dentry) 203 dentry = dget_parent(dparent); 204 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp)) 205 dentry = dget(dparent); /* .. == . just like at / */ 206 else { 207 /* checking mountpoint crossing is very different when stepping up */ 208 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry); 209 if (host_err) 210 goto out_nfserr; 211 } 212 } else { 213 fh_lock(fhp); 214 dentry = lookup_one_len(name, dparent, len); 215 host_err = PTR_ERR(dentry); 216 if (IS_ERR(dentry)) 217 goto out_nfserr; 218 /* 219 * check if we have crossed a mount point ... 220 */ 221 if (nfsd_mountpoint(dentry, exp)) { 222 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) { 223 dput(dentry); 224 goto out_nfserr; 225 } 226 } 227 } 228 *dentry_ret = dentry; 229 *exp_ret = exp; 230 return 0; 231 232 out_nfserr: 233 exp_put(exp); 234 return nfserrno(host_err); 235 } 236 237 /* 238 * Look up one component of a pathname. 239 * N.B. After this call _both_ fhp and resfh need an fh_put 240 * 241 * If the lookup would cross a mountpoint, and the mounted filesystem 242 * is exported to the client with NFSEXP_NOHIDE, then the lookup is 243 * accepted as it stands and the mounted directory is 244 * returned. Otherwise the covered directory is returned. 245 * NOTE: this mountpoint crossing is not supported properly by all 246 * clients and is explicitly disallowed for NFSv3 247 * NeilBrown <neilb@cse.unsw.edu.au> 248 */ 249 __be32 250 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, 251 unsigned int len, struct svc_fh *resfh) 252 { 253 struct svc_export *exp; 254 struct dentry *dentry; 255 __be32 err; 256 257 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry); 258 if (err) 259 return err; 260 err = check_nfsd_access(exp, rqstp); 261 if (err) 262 goto out; 263 /* 264 * Note: we compose the file handle now, but as the 265 * dentry may be negative, it may need to be updated. 266 */ 267 err = fh_compose(resfh, exp, dentry, fhp); 268 if (!err && !dentry->d_inode) 269 err = nfserr_noent; 270 out: 271 dput(dentry); 272 exp_put(exp); 273 return err; 274 } 275 276 /* 277 * Commit metadata changes to stable storage. 278 */ 279 static int 280 commit_metadata(struct svc_fh *fhp) 281 { 282 struct inode *inode = fhp->fh_dentry->d_inode; 283 const struct export_operations *export_ops = inode->i_sb->s_export_op; 284 285 if (!EX_ISSYNC(fhp->fh_export)) 286 return 0; 287 288 if (export_ops->commit_metadata) 289 return export_ops->commit_metadata(inode); 290 return sync_inode_metadata(inode, 1); 291 } 292 293 /* 294 * Set various file attributes. 295 * N.B. After this call fhp needs an fh_put 296 */ 297 __be32 298 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 299 int check_guard, time_t guardtime) 300 { 301 struct dentry *dentry; 302 struct inode *inode; 303 int accmode = NFSD_MAY_SATTR; 304 int ftype = 0; 305 __be32 err; 306 int host_err; 307 int size_change = 0; 308 309 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 310 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; 311 if (iap->ia_valid & ATTR_SIZE) 312 ftype = S_IFREG; 313 314 /* Get inode */ 315 err = fh_verify(rqstp, fhp, ftype, accmode); 316 if (err) 317 goto out; 318 319 dentry = fhp->fh_dentry; 320 inode = dentry->d_inode; 321 322 /* Ignore any mode updates on symlinks */ 323 if (S_ISLNK(inode->i_mode)) 324 iap->ia_valid &= ~ATTR_MODE; 325 326 if (!iap->ia_valid) 327 goto out; 328 329 /* 330 * NFSv2 does not differentiate between "set-[ac]time-to-now" 331 * which only requires access, and "set-[ac]time-to-X" which 332 * requires ownership. 333 * So if it looks like it might be "set both to the same time which 334 * is close to now", and if inode_change_ok fails, then we 335 * convert to "set to now" instead of "set to explicit time" 336 * 337 * We only call inode_change_ok as the last test as technically 338 * it is not an interface that we should be using. It is only 339 * valid if the filesystem does not define it's own i_op->setattr. 340 */ 341 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 342 #define MAX_TOUCH_TIME_ERROR (30*60) 343 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && 344 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) { 345 /* 346 * Looks probable. 347 * 348 * Now just make sure time is in the right ballpark. 349 * Solaris, at least, doesn't seem to care what the time 350 * request is. We require it be within 30 minutes of now. 351 */ 352 time_t delta = iap->ia_atime.tv_sec - get_seconds(); 353 if (delta < 0) 354 delta = -delta; 355 if (delta < MAX_TOUCH_TIME_ERROR && 356 inode_change_ok(inode, iap) != 0) { 357 /* 358 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME. 359 * This will cause notify_change to set these times 360 * to "now" 361 */ 362 iap->ia_valid &= ~BOTH_TIME_SET; 363 } 364 } 365 366 /* 367 * The size case is special. 368 * It changes the file as well as the attributes. 369 */ 370 if (iap->ia_valid & ATTR_SIZE) { 371 if (iap->ia_size < inode->i_size) { 372 err = nfsd_permission(rqstp, fhp->fh_export, dentry, 373 NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE); 374 if (err) 375 goto out; 376 } 377 378 /* 379 * If we are changing the size of the file, then 380 * we need to break all leases. 381 */ 382 host_err = break_lease(inode, O_WRONLY | O_NONBLOCK); 383 if (host_err == -EWOULDBLOCK) 384 host_err = -ETIMEDOUT; 385 if (host_err) /* ENOMEM or EWOULDBLOCK */ 386 goto out_nfserr; 387 388 host_err = get_write_access(inode); 389 if (host_err) 390 goto out_nfserr; 391 392 size_change = 1; 393 host_err = locks_verify_truncate(inode, NULL, iap->ia_size); 394 if (host_err) { 395 put_write_access(inode); 396 goto out_nfserr; 397 } 398 } 399 400 /* sanitize the mode change */ 401 if (iap->ia_valid & ATTR_MODE) { 402 iap->ia_mode &= S_IALLUGO; 403 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); 404 } 405 406 /* Revoke setuid/setgid on chown */ 407 if (!S_ISDIR(inode->i_mode) && 408 (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) || 409 ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) { 410 iap->ia_valid |= ATTR_KILL_PRIV; 411 if (iap->ia_valid & ATTR_MODE) { 412 /* we're setting mode too, just clear the s*id bits */ 413 iap->ia_mode &= ~S_ISUID; 414 if (iap->ia_mode & S_IXGRP) 415 iap->ia_mode &= ~S_ISGID; 416 } else { 417 /* set ATTR_KILL_* bits and let VFS handle it */ 418 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID); 419 } 420 } 421 422 /* Change the attributes. */ 423 424 iap->ia_valid |= ATTR_CTIME; 425 426 err = nfserr_notsync; 427 if (!check_guard || guardtime == inode->i_ctime.tv_sec) { 428 fh_lock(fhp); 429 host_err = notify_change(dentry, iap); 430 err = nfserrno(host_err); 431 fh_unlock(fhp); 432 } 433 if (size_change) 434 put_write_access(inode); 435 if (!err) 436 commit_metadata(fhp); 437 out: 438 return err; 439 440 out_nfserr: 441 err = nfserrno(host_err); 442 goto out; 443 } 444 445 #if defined(CONFIG_NFSD_V2_ACL) || \ 446 defined(CONFIG_NFSD_V3_ACL) || \ 447 defined(CONFIG_NFSD_V4) 448 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf) 449 { 450 ssize_t buflen; 451 ssize_t ret; 452 453 buflen = vfs_getxattr(dentry, key, NULL, 0); 454 if (buflen <= 0) 455 return buflen; 456 457 *buf = kmalloc(buflen, GFP_KERNEL); 458 if (!*buf) 459 return -ENOMEM; 460 461 ret = vfs_getxattr(dentry, key, *buf, buflen); 462 if (ret < 0) 463 kfree(*buf); 464 return ret; 465 } 466 #endif 467 468 #if defined(CONFIG_NFSD_V4) 469 static int 470 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key) 471 { 472 int len; 473 size_t buflen; 474 char *buf = NULL; 475 int error = 0; 476 477 buflen = posix_acl_xattr_size(pacl->a_count); 478 buf = kmalloc(buflen, GFP_KERNEL); 479 error = -ENOMEM; 480 if (buf == NULL) 481 goto out; 482 483 len = posix_acl_to_xattr(pacl, buf, buflen); 484 if (len < 0) { 485 error = len; 486 goto out; 487 } 488 489 error = vfs_setxattr(dentry, key, buf, len, 0); 490 out: 491 kfree(buf); 492 return error; 493 } 494 495 __be32 496 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 497 struct nfs4_acl *acl) 498 { 499 __be32 error; 500 int host_error; 501 struct dentry *dentry; 502 struct inode *inode; 503 struct posix_acl *pacl = NULL, *dpacl = NULL; 504 unsigned int flags = 0; 505 506 /* Get inode */ 507 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); 508 if (error) 509 return error; 510 511 dentry = fhp->fh_dentry; 512 inode = dentry->d_inode; 513 if (S_ISDIR(inode->i_mode)) 514 flags = NFS4_ACL_DIR; 515 516 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 517 if (host_error == -EINVAL) { 518 return nfserr_attrnotsupp; 519 } else if (host_error < 0) 520 goto out_nfserr; 521 522 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); 523 if (host_error < 0) 524 goto out_release; 525 526 if (S_ISDIR(inode->i_mode)) 527 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); 528 529 out_release: 530 posix_acl_release(pacl); 531 posix_acl_release(dpacl); 532 out_nfserr: 533 if (host_error == -EOPNOTSUPP) 534 return nfserr_attrnotsupp; 535 else 536 return nfserrno(host_error); 537 } 538 539 static struct posix_acl * 540 _get_posix_acl(struct dentry *dentry, char *key) 541 { 542 void *buf = NULL; 543 struct posix_acl *pacl = NULL; 544 int buflen; 545 546 buflen = nfsd_getxattr(dentry, key, &buf); 547 if (!buflen) 548 buflen = -ENODATA; 549 if (buflen <= 0) 550 return ERR_PTR(buflen); 551 552 pacl = posix_acl_from_xattr(buf, buflen); 553 kfree(buf); 554 return pacl; 555 } 556 557 int 558 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl) 559 { 560 struct inode *inode = dentry->d_inode; 561 int error = 0; 562 struct posix_acl *pacl = NULL, *dpacl = NULL; 563 unsigned int flags = 0; 564 565 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS); 566 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA) 567 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 568 if (IS_ERR(pacl)) { 569 error = PTR_ERR(pacl); 570 pacl = NULL; 571 goto out; 572 } 573 574 if (S_ISDIR(inode->i_mode)) { 575 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT); 576 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA) 577 dpacl = NULL; 578 else if (IS_ERR(dpacl)) { 579 error = PTR_ERR(dpacl); 580 dpacl = NULL; 581 goto out; 582 } 583 flags = NFS4_ACL_DIR; 584 } 585 586 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags); 587 if (IS_ERR(*acl)) { 588 error = PTR_ERR(*acl); 589 *acl = NULL; 590 } 591 out: 592 posix_acl_release(pacl); 593 posix_acl_release(dpacl); 594 return error; 595 } 596 597 #endif /* defined(CONFIG_NFSD_V4) */ 598 599 #ifdef CONFIG_NFSD_V3 600 /* 601 * Check server access rights to a file system object 602 */ 603 struct accessmap { 604 u32 access; 605 int how; 606 }; 607 static struct accessmap nfs3_regaccess[] = { 608 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 609 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 610 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, 611 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, 612 613 { 0, 0 } 614 }; 615 616 static struct accessmap nfs3_diraccess[] = { 617 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 618 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, 619 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, 620 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, 621 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, 622 623 { 0, 0 } 624 }; 625 626 static struct accessmap nfs3_anyaccess[] = { 627 /* Some clients - Solaris 2.6 at least, make an access call 628 * to the server to check for access for things like /dev/null 629 * (which really, the server doesn't care about). So 630 * We provide simple access checking for them, looking 631 * mainly at mode bits, and we make sure to ignore read-only 632 * filesystem checks 633 */ 634 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 635 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 636 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 637 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 638 639 { 0, 0 } 640 }; 641 642 __be32 643 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 644 { 645 struct accessmap *map; 646 struct svc_export *export; 647 struct dentry *dentry; 648 u32 query, result = 0, sresult = 0; 649 __be32 error; 650 651 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP); 652 if (error) 653 goto out; 654 655 export = fhp->fh_export; 656 dentry = fhp->fh_dentry; 657 658 if (S_ISREG(dentry->d_inode->i_mode)) 659 map = nfs3_regaccess; 660 else if (S_ISDIR(dentry->d_inode->i_mode)) 661 map = nfs3_diraccess; 662 else 663 map = nfs3_anyaccess; 664 665 666 query = *access; 667 for (; map->access; map++) { 668 if (map->access & query) { 669 __be32 err2; 670 671 sresult |= map->access; 672 673 err2 = nfsd_permission(rqstp, export, dentry, map->how); 674 switch (err2) { 675 case nfs_ok: 676 result |= map->access; 677 break; 678 679 /* the following error codes just mean the access was not allowed, 680 * rather than an error occurred */ 681 case nfserr_rofs: 682 case nfserr_acces: 683 case nfserr_perm: 684 /* simply don't "or" in the access bit. */ 685 break; 686 default: 687 error = err2; 688 goto out; 689 } 690 } 691 } 692 *access = result; 693 if (supported) 694 *supported = sresult; 695 696 out: 697 return error; 698 } 699 #endif /* CONFIG_NFSD_V3 */ 700 701 702 703 /* 704 * Open an existing file or directory. 705 * The access argument indicates the type of open (read/write/lock) 706 * N.B. After this call fhp needs an fh_put 707 */ 708 __be32 709 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 710 int access, struct file **filp) 711 { 712 struct dentry *dentry; 713 struct inode *inode; 714 int flags = O_RDONLY|O_LARGEFILE; 715 __be32 err; 716 int host_err = 0; 717 718 validate_process_creds(); 719 720 /* 721 * If we get here, then the client has already done an "open", 722 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 723 * in case a chmod has now revoked permission. 724 */ 725 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE); 726 if (err) 727 goto out; 728 729 dentry = fhp->fh_dentry; 730 inode = dentry->d_inode; 731 732 /* Disallow write access to files with the append-only bit set 733 * or any access when mandatory locking enabled 734 */ 735 err = nfserr_perm; 736 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE)) 737 goto out; 738 /* 739 * We must ignore files (but only files) which might have mandatory 740 * locks on them because there is no way to know if the accesser has 741 * the lock. 742 */ 743 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode)) 744 goto out; 745 746 if (!inode->i_fop) 747 goto out; 748 749 /* 750 * Check to see if there are any leases on this file. 751 * This may block while leases are broken. 752 */ 753 if (!(access & NFSD_MAY_NOT_BREAK_LEASE)) 754 host_err = break_lease(inode, O_NONBLOCK | ((access & NFSD_MAY_WRITE) ? O_WRONLY : 0)); 755 if (host_err == -EWOULDBLOCK) 756 host_err = -ETIMEDOUT; 757 if (host_err) /* NOMEM or WOULDBLOCK */ 758 goto out_nfserr; 759 760 if (access & NFSD_MAY_WRITE) { 761 if (access & NFSD_MAY_READ) 762 flags = O_RDWR|O_LARGEFILE; 763 else 764 flags = O_WRONLY|O_LARGEFILE; 765 } 766 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt), 767 flags, current_cred()); 768 if (IS_ERR(*filp)) 769 host_err = PTR_ERR(*filp); 770 else 771 host_err = ima_file_check(*filp, access); 772 out_nfserr: 773 err = nfserrno(host_err); 774 out: 775 validate_process_creds(); 776 return err; 777 } 778 779 /* 780 * Close a file. 781 */ 782 void 783 nfsd_close(struct file *filp) 784 { 785 fput(filp); 786 } 787 788 /* 789 * Obtain the readahead parameters for the file 790 * specified by (dev, ino). 791 */ 792 793 static inline struct raparms * 794 nfsd_get_raparms(dev_t dev, ino_t ino) 795 { 796 struct raparms *ra, **rap, **frap = NULL; 797 int depth = 0; 798 unsigned int hash; 799 struct raparm_hbucket *rab; 800 801 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK; 802 rab = &raparm_hash[hash]; 803 804 spin_lock(&rab->pb_lock); 805 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) { 806 if (ra->p_ino == ino && ra->p_dev == dev) 807 goto found; 808 depth++; 809 if (ra->p_count == 0) 810 frap = rap; 811 } 812 depth = nfsdstats.ra_size*11/10; 813 if (!frap) { 814 spin_unlock(&rab->pb_lock); 815 return NULL; 816 } 817 rap = frap; 818 ra = *frap; 819 ra->p_dev = dev; 820 ra->p_ino = ino; 821 ra->p_set = 0; 822 ra->p_hindex = hash; 823 found: 824 if (rap != &rab->pb_head) { 825 *rap = ra->p_next; 826 ra->p_next = rab->pb_head; 827 rab->pb_head = ra; 828 } 829 ra->p_count++; 830 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 831 spin_unlock(&rab->pb_lock); 832 return ra; 833 } 834 835 /* 836 * Grab and keep cached pages associated with a file in the svc_rqst 837 * so that they can be passed to the network sendmsg/sendpage routines 838 * directly. They will be released after the sending has completed. 839 */ 840 static int 841 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 842 struct splice_desc *sd) 843 { 844 struct svc_rqst *rqstp = sd->u.data; 845 struct page **pp = rqstp->rq_respages + rqstp->rq_resused; 846 struct page *page = buf->page; 847 size_t size; 848 int ret; 849 850 ret = buf->ops->confirm(pipe, buf); 851 if (unlikely(ret)) 852 return ret; 853 854 size = sd->len; 855 856 if (rqstp->rq_res.page_len == 0) { 857 get_page(page); 858 put_page(*pp); 859 *pp = page; 860 rqstp->rq_resused++; 861 rqstp->rq_res.page_base = buf->offset; 862 rqstp->rq_res.page_len = size; 863 } else if (page != pp[-1]) { 864 get_page(page); 865 if (*pp) 866 put_page(*pp); 867 *pp = page; 868 rqstp->rq_resused++; 869 rqstp->rq_res.page_len += size; 870 } else 871 rqstp->rq_res.page_len += size; 872 873 return size; 874 } 875 876 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, 877 struct splice_desc *sd) 878 { 879 return __splice_from_pipe(pipe, sd, nfsd_splice_actor); 880 } 881 882 static inline int svc_msnfs(struct svc_fh *ffhp) 883 { 884 #ifdef MSNFS 885 return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS); 886 #else 887 return 0; 888 #endif 889 } 890 891 static __be32 892 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 893 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 894 { 895 struct inode *inode; 896 mm_segment_t oldfs; 897 __be32 err; 898 int host_err; 899 900 err = nfserr_perm; 901 inode = file->f_path.dentry->d_inode; 902 903 if (svc_msnfs(fhp) && !lock_may_read(inode, offset, *count)) 904 goto out; 905 906 if (file->f_op->splice_read && rqstp->rq_splice_ok) { 907 struct splice_desc sd = { 908 .len = 0, 909 .total_len = *count, 910 .pos = offset, 911 .u.data = rqstp, 912 }; 913 914 rqstp->rq_resused = 1; 915 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); 916 } else { 917 oldfs = get_fs(); 918 set_fs(KERNEL_DS); 919 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 920 set_fs(oldfs); 921 } 922 923 if (host_err >= 0) { 924 nfsdstats.io_read += host_err; 925 *count = host_err; 926 err = 0; 927 fsnotify_access(file); 928 } else 929 err = nfserrno(host_err); 930 out: 931 return err; 932 } 933 934 static void kill_suid(struct dentry *dentry) 935 { 936 struct iattr ia; 937 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; 938 939 mutex_lock(&dentry->d_inode->i_mutex); 940 notify_change(dentry, &ia); 941 mutex_unlock(&dentry->d_inode->i_mutex); 942 } 943 944 /* 945 * Gathered writes: If another process is currently writing to the file, 946 * there's a high chance this is another nfsd (triggered by a bulk write 947 * from a client's biod). Rather than syncing the file with each write 948 * request, we sleep for 10 msec. 949 * 950 * I don't know if this roughly approximates C. Juszak's idea of 951 * gathered writes, but it's a nice and simple solution (IMHO), and it 952 * seems to work:-) 953 * 954 * Note: we do this only in the NFSv2 case, since v3 and higher have a 955 * better tool (separate unstable writes and commits) for solving this 956 * problem. 957 */ 958 static int wait_for_concurrent_writes(struct file *file) 959 { 960 struct inode *inode = file->f_path.dentry->d_inode; 961 static ino_t last_ino; 962 static dev_t last_dev; 963 int err = 0; 964 965 if (atomic_read(&inode->i_writecount) > 1 966 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 967 dprintk("nfsd: write defer %d\n", task_pid_nr(current)); 968 msleep(10); 969 dprintk("nfsd: write resume %d\n", task_pid_nr(current)); 970 } 971 972 if (inode->i_state & I_DIRTY) { 973 dprintk("nfsd: write sync %d\n", task_pid_nr(current)); 974 err = vfs_fsync(file, 0); 975 } 976 last_ino = inode->i_ino; 977 last_dev = inode->i_sb->s_dev; 978 return err; 979 } 980 981 static __be32 982 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 983 loff_t offset, struct kvec *vec, int vlen, 984 unsigned long *cnt, int *stablep) 985 { 986 struct svc_export *exp; 987 struct dentry *dentry; 988 struct inode *inode; 989 mm_segment_t oldfs; 990 __be32 err = 0; 991 int host_err; 992 int stable = *stablep; 993 int use_wgather; 994 995 #ifdef MSNFS 996 err = nfserr_perm; 997 998 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 999 (!lock_may_write(file->f_path.dentry->d_inode, offset, *cnt))) 1000 goto out; 1001 #endif 1002 1003 dentry = file->f_path.dentry; 1004 inode = dentry->d_inode; 1005 exp = fhp->fh_export; 1006 1007 /* 1008 * Request sync writes if 1009 * - the sync export option has been set, or 1010 * - the client requested O_SYNC behavior (NFSv3 feature). 1011 * - The file system doesn't support fsync(). 1012 * When NFSv2 gathered writes have been configured for this volume, 1013 * flushing the data to disk is handled separately below. 1014 */ 1015 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); 1016 1017 if (!file->f_op->fsync) {/* COMMIT3 cannot work */ 1018 stable = 2; 1019 *stablep = 2; /* FILE_SYNC */ 1020 } 1021 1022 if (!EX_ISSYNC(exp)) 1023 stable = 0; 1024 if (stable && !use_wgather) { 1025 spin_lock(&file->f_lock); 1026 file->f_flags |= O_SYNC; 1027 spin_unlock(&file->f_lock); 1028 } 1029 1030 /* Write the data. */ 1031 oldfs = get_fs(); set_fs(KERNEL_DS); 1032 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); 1033 set_fs(oldfs); 1034 if (host_err < 0) 1035 goto out_nfserr; 1036 *cnt = host_err; 1037 nfsdstats.io_write += host_err; 1038 fsnotify_modify(file); 1039 1040 /* clear setuid/setgid flag after write */ 1041 if (inode->i_mode & (S_ISUID | S_ISGID)) 1042 kill_suid(dentry); 1043 1044 if (stable && use_wgather) 1045 host_err = wait_for_concurrent_writes(file); 1046 1047 out_nfserr: 1048 dprintk("nfsd: write complete host_err=%d\n", host_err); 1049 if (host_err >= 0) 1050 err = 0; 1051 else 1052 err = nfserrno(host_err); 1053 out: 1054 return err; 1055 } 1056 1057 /* 1058 * Read data from a file. count must contain the requested read count 1059 * on entry. On return, *count contains the number of bytes actually read. 1060 * N.B. After this call fhp needs an fh_put 1061 */ 1062 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 1063 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 1064 { 1065 struct file *file; 1066 struct inode *inode; 1067 struct raparms *ra; 1068 __be32 err; 1069 1070 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); 1071 if (err) 1072 return err; 1073 1074 inode = file->f_path.dentry->d_inode; 1075 1076 /* Get readahead parameters */ 1077 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 1078 1079 if (ra && ra->p_set) 1080 file->f_ra = ra->p_ra; 1081 1082 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1083 1084 /* Write back readahead params */ 1085 if (ra) { 1086 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex]; 1087 spin_lock(&rab->pb_lock); 1088 ra->p_ra = file->f_ra; 1089 ra->p_set = 1; 1090 ra->p_count--; 1091 spin_unlock(&rab->pb_lock); 1092 } 1093 1094 nfsd_close(file); 1095 return err; 1096 } 1097 1098 /* As above, but use the provided file descriptor. */ 1099 __be32 1100 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1101 loff_t offset, struct kvec *vec, int vlen, 1102 unsigned long *count) 1103 { 1104 __be32 err; 1105 1106 if (file) { 1107 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1108 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE); 1109 if (err) 1110 goto out; 1111 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1112 } else /* Note file may still be NULL in NFSv4 special stateid case: */ 1113 err = nfsd_read(rqstp, fhp, offset, vec, vlen, count); 1114 out: 1115 return err; 1116 } 1117 1118 /* 1119 * Write data to a file. 1120 * The stable flag requests synchronous writes. 1121 * N.B. After this call fhp needs an fh_put 1122 */ 1123 __be32 1124 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1125 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, 1126 int *stablep) 1127 { 1128 __be32 err = 0; 1129 1130 if (file) { 1131 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1132 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE); 1133 if (err) 1134 goto out; 1135 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1136 stablep); 1137 } else { 1138 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); 1139 if (err) 1140 goto out; 1141 1142 if (cnt) 1143 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1144 cnt, stablep); 1145 nfsd_close(file); 1146 } 1147 out: 1148 return err; 1149 } 1150 1151 #ifdef CONFIG_NFSD_V3 1152 /* 1153 * Commit all pending writes to stable storage. 1154 * 1155 * Note: we only guarantee that data that lies within the range specified 1156 * by the 'offset' and 'count' parameters will be synced. 1157 * 1158 * Unfortunately we cannot lock the file to make sure we return full WCC 1159 * data to the client, as locking happens lower down in the filesystem. 1160 */ 1161 __be32 1162 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1163 loff_t offset, unsigned long count) 1164 { 1165 struct file *file; 1166 loff_t end = LLONG_MAX; 1167 __be32 err = nfserr_inval; 1168 1169 if (offset < 0) 1170 goto out; 1171 if (count != 0) { 1172 end = offset + (loff_t)count - 1; 1173 if (end < offset) 1174 goto out; 1175 } 1176 1177 err = nfsd_open(rqstp, fhp, S_IFREG, 1178 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file); 1179 if (err) 1180 goto out; 1181 if (EX_ISSYNC(fhp->fh_export)) { 1182 int err2 = vfs_fsync_range(file, offset, end, 0); 1183 1184 if (err2 != -EINVAL) 1185 err = nfserrno(err2); 1186 else 1187 err = nfserr_notsupp; 1188 } 1189 1190 nfsd_close(file); 1191 out: 1192 return err; 1193 } 1194 #endif /* CONFIG_NFSD_V3 */ 1195 1196 static __be32 1197 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp, 1198 struct iattr *iap) 1199 { 1200 /* 1201 * Mode has already been set earlier in create: 1202 */ 1203 iap->ia_valid &= ~ATTR_MODE; 1204 /* 1205 * Setting uid/gid works only for root. Irix appears to 1206 * send along the gid on create when it tries to implement 1207 * setgid directories via NFS: 1208 */ 1209 if (current_fsuid() != 0) 1210 iap->ia_valid &= ~(ATTR_UID|ATTR_GID); 1211 if (iap->ia_valid) 1212 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1213 return 0; 1214 } 1215 1216 /* HPUX client sometimes creates a file in mode 000, and sets size to 0. 1217 * setting size to 0 may fail for some specific file systems by the permission 1218 * checking which requires WRITE permission but the mode is 000. 1219 * we ignore the resizing(to 0) on the just new created file, since the size is 1220 * 0 after file created. 1221 * 1222 * call this only after vfs_create() is called. 1223 * */ 1224 static void 1225 nfsd_check_ignore_resizing(struct iattr *iap) 1226 { 1227 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) 1228 iap->ia_valid &= ~ATTR_SIZE; 1229 } 1230 1231 /* 1232 * Create a file (regular, directory, device, fifo); UNIX sockets 1233 * not yet implemented. 1234 * If the response fh has been verified, the parent directory should 1235 * already be locked. Note that the parent directory is left locked. 1236 * 1237 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1238 */ 1239 __be32 1240 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1241 char *fname, int flen, struct iattr *iap, 1242 int type, dev_t rdev, struct svc_fh *resfhp) 1243 { 1244 struct dentry *dentry, *dchild = NULL; 1245 struct inode *dirp; 1246 __be32 err; 1247 __be32 err2; 1248 int host_err; 1249 1250 err = nfserr_perm; 1251 if (!flen) 1252 goto out; 1253 err = nfserr_exist; 1254 if (isdotent(fname, flen)) 1255 goto out; 1256 1257 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1258 if (err) 1259 goto out; 1260 1261 dentry = fhp->fh_dentry; 1262 dirp = dentry->d_inode; 1263 1264 err = nfserr_notdir; 1265 if (!dirp->i_op->lookup) 1266 goto out; 1267 /* 1268 * Check whether the response file handle has been verified yet. 1269 * If it has, the parent directory should already be locked. 1270 */ 1271 if (!resfhp->fh_dentry) { 1272 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1273 fh_lock_nested(fhp, I_MUTEX_PARENT); 1274 dchild = lookup_one_len(fname, dentry, flen); 1275 host_err = PTR_ERR(dchild); 1276 if (IS_ERR(dchild)) 1277 goto out_nfserr; 1278 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1279 if (err) 1280 goto out; 1281 } else { 1282 /* called from nfsd_proc_create */ 1283 dchild = dget(resfhp->fh_dentry); 1284 if (!fhp->fh_locked) { 1285 /* not actually possible */ 1286 printk(KERN_ERR 1287 "nfsd_create: parent %s/%s not locked!\n", 1288 dentry->d_parent->d_name.name, 1289 dentry->d_name.name); 1290 err = nfserr_io; 1291 goto out; 1292 } 1293 } 1294 /* 1295 * Make sure the child dentry is still negative ... 1296 */ 1297 err = nfserr_exist; 1298 if (dchild->d_inode) { 1299 dprintk("nfsd_create: dentry %s/%s not negative!\n", 1300 dentry->d_name.name, dchild->d_name.name); 1301 goto out; 1302 } 1303 1304 if (!(iap->ia_valid & ATTR_MODE)) 1305 iap->ia_mode = 0; 1306 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1307 1308 err = nfserr_inval; 1309 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) { 1310 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", 1311 type); 1312 goto out; 1313 } 1314 1315 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1316 if (host_err) 1317 goto out_nfserr; 1318 1319 /* 1320 * Get the dir op function pointer. 1321 */ 1322 err = 0; 1323 switch (type) { 1324 case S_IFREG: 1325 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1326 if (!host_err) 1327 nfsd_check_ignore_resizing(iap); 1328 break; 1329 case S_IFDIR: 1330 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1331 break; 1332 case S_IFCHR: 1333 case S_IFBLK: 1334 case S_IFIFO: 1335 case S_IFSOCK: 1336 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1337 break; 1338 } 1339 if (host_err < 0) { 1340 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1341 goto out_nfserr; 1342 } 1343 1344 err = nfsd_create_setattr(rqstp, resfhp, iap); 1345 1346 /* 1347 * nfsd_setattr already committed the child. Transactional filesystems 1348 * had a chance to commit changes for both parent and child 1349 * simultaneously making the following commit_metadata a noop. 1350 */ 1351 err2 = nfserrno(commit_metadata(fhp)); 1352 if (err2) 1353 err = err2; 1354 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1355 /* 1356 * Update the file handle to get the new inode info. 1357 */ 1358 if (!err) 1359 err = fh_update(resfhp); 1360 out: 1361 if (dchild && !IS_ERR(dchild)) 1362 dput(dchild); 1363 return err; 1364 1365 out_nfserr: 1366 err = nfserrno(host_err); 1367 goto out; 1368 } 1369 1370 #ifdef CONFIG_NFSD_V3 1371 /* 1372 * NFSv3 version of nfsd_create 1373 */ 1374 __be32 1375 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, 1376 char *fname, int flen, struct iattr *iap, 1377 struct svc_fh *resfhp, int createmode, u32 *verifier, 1378 int *truncp, int *created) 1379 { 1380 struct dentry *dentry, *dchild = NULL; 1381 struct inode *dirp; 1382 __be32 err; 1383 int host_err; 1384 __u32 v_mtime=0, v_atime=0; 1385 1386 err = nfserr_perm; 1387 if (!flen) 1388 goto out; 1389 err = nfserr_exist; 1390 if (isdotent(fname, flen)) 1391 goto out; 1392 if (!(iap->ia_valid & ATTR_MODE)) 1393 iap->ia_mode = 0; 1394 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1395 if (err) 1396 goto out; 1397 1398 dentry = fhp->fh_dentry; 1399 dirp = dentry->d_inode; 1400 1401 /* Get all the sanity checks out of the way before 1402 * we lock the parent. */ 1403 err = nfserr_notdir; 1404 if (!dirp->i_op->lookup) 1405 goto out; 1406 fh_lock_nested(fhp, I_MUTEX_PARENT); 1407 1408 /* 1409 * Compose the response file handle. 1410 */ 1411 dchild = lookup_one_len(fname, dentry, flen); 1412 host_err = PTR_ERR(dchild); 1413 if (IS_ERR(dchild)) 1414 goto out_nfserr; 1415 1416 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1417 if (err) 1418 goto out; 1419 1420 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1421 /* solaris7 gets confused (bugid 4218508) if these have 1422 * the high bit set, so just clear the high bits. If this is 1423 * ever changed to use different attrs for storing the 1424 * verifier, then do_open_lookup() will also need to be fixed 1425 * accordingly. 1426 */ 1427 v_mtime = verifier[0]&0x7fffffff; 1428 v_atime = verifier[1]&0x7fffffff; 1429 } 1430 1431 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1432 if (host_err) 1433 goto out_nfserr; 1434 if (dchild->d_inode) { 1435 err = 0; 1436 1437 switch (createmode) { 1438 case NFS3_CREATE_UNCHECKED: 1439 if (! S_ISREG(dchild->d_inode->i_mode)) 1440 err = nfserr_exist; 1441 else if (truncp) { 1442 /* in nfsv4, we need to treat this case a little 1443 * differently. we don't want to truncate the 1444 * file now; this would be wrong if the OPEN 1445 * fails for some other reason. furthermore, 1446 * if the size is nonzero, we should ignore it 1447 * according to spec! 1448 */ 1449 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1450 } 1451 else { 1452 iap->ia_valid &= ATTR_SIZE; 1453 goto set_attr; 1454 } 1455 break; 1456 case NFS3_CREATE_EXCLUSIVE: 1457 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1458 && dchild->d_inode->i_atime.tv_sec == v_atime 1459 && dchild->d_inode->i_size == 0 ) 1460 break; 1461 /* fallthru */ 1462 case NFS3_CREATE_GUARDED: 1463 err = nfserr_exist; 1464 } 1465 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1466 goto out; 1467 } 1468 1469 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1470 if (host_err < 0) { 1471 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1472 goto out_nfserr; 1473 } 1474 if (created) 1475 *created = 1; 1476 1477 nfsd_check_ignore_resizing(iap); 1478 1479 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1480 /* Cram the verifier into atime/mtime */ 1481 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1482 | ATTR_MTIME_SET|ATTR_ATIME_SET; 1483 /* XXX someone who knows this better please fix it for nsec */ 1484 iap->ia_mtime.tv_sec = v_mtime; 1485 iap->ia_atime.tv_sec = v_atime; 1486 iap->ia_mtime.tv_nsec = 0; 1487 iap->ia_atime.tv_nsec = 0; 1488 } 1489 1490 set_attr: 1491 err = nfsd_create_setattr(rqstp, resfhp, iap); 1492 1493 /* 1494 * nfsd_setattr already committed the child (and possibly also the parent). 1495 */ 1496 if (!err) 1497 err = nfserrno(commit_metadata(fhp)); 1498 1499 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1500 /* 1501 * Update the filehandle to get the new inode info. 1502 */ 1503 if (!err) 1504 err = fh_update(resfhp); 1505 1506 out: 1507 fh_unlock(fhp); 1508 if (dchild && !IS_ERR(dchild)) 1509 dput(dchild); 1510 return err; 1511 1512 out_nfserr: 1513 err = nfserrno(host_err); 1514 goto out; 1515 } 1516 #endif /* CONFIG_NFSD_V3 */ 1517 1518 /* 1519 * Read a symlink. On entry, *lenp must contain the maximum path length that 1520 * fits into the buffer. On return, it contains the true length. 1521 * N.B. After this call fhp needs an fh_put 1522 */ 1523 __be32 1524 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1525 { 1526 struct dentry *dentry; 1527 struct inode *inode; 1528 mm_segment_t oldfs; 1529 __be32 err; 1530 int host_err; 1531 1532 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); 1533 if (err) 1534 goto out; 1535 1536 dentry = fhp->fh_dentry; 1537 inode = dentry->d_inode; 1538 1539 err = nfserr_inval; 1540 if (!inode->i_op->readlink) 1541 goto out; 1542 1543 touch_atime(fhp->fh_export->ex_path.mnt, dentry); 1544 /* N.B. Why does this call need a get_fs()?? 1545 * Remove the set_fs and watch the fireworks:-) --okir 1546 */ 1547 1548 oldfs = get_fs(); set_fs(KERNEL_DS); 1549 host_err = inode->i_op->readlink(dentry, buf, *lenp); 1550 set_fs(oldfs); 1551 1552 if (host_err < 0) 1553 goto out_nfserr; 1554 *lenp = host_err; 1555 err = 0; 1556 out: 1557 return err; 1558 1559 out_nfserr: 1560 err = nfserrno(host_err); 1561 goto out; 1562 } 1563 1564 /* 1565 * Create a symlink and look up its inode 1566 * N.B. After this call _both_ fhp and resfhp need an fh_put 1567 */ 1568 __be32 1569 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1570 char *fname, int flen, 1571 char *path, int plen, 1572 struct svc_fh *resfhp, 1573 struct iattr *iap) 1574 { 1575 struct dentry *dentry, *dnew; 1576 __be32 err, cerr; 1577 int host_err; 1578 1579 err = nfserr_noent; 1580 if (!flen || !plen) 1581 goto out; 1582 err = nfserr_exist; 1583 if (isdotent(fname, flen)) 1584 goto out; 1585 1586 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1587 if (err) 1588 goto out; 1589 fh_lock(fhp); 1590 dentry = fhp->fh_dentry; 1591 dnew = lookup_one_len(fname, dentry, flen); 1592 host_err = PTR_ERR(dnew); 1593 if (IS_ERR(dnew)) 1594 goto out_nfserr; 1595 1596 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1597 if (host_err) 1598 goto out_nfserr; 1599 1600 if (unlikely(path[plen] != 0)) { 1601 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1602 if (path_alloced == NULL) 1603 host_err = -ENOMEM; 1604 else { 1605 strncpy(path_alloced, path, plen); 1606 path_alloced[plen] = 0; 1607 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced); 1608 kfree(path_alloced); 1609 } 1610 } else 1611 host_err = vfs_symlink(dentry->d_inode, dnew, path); 1612 err = nfserrno(host_err); 1613 if (!err) 1614 err = nfserrno(commit_metadata(fhp)); 1615 fh_unlock(fhp); 1616 1617 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1618 1619 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1620 dput(dnew); 1621 if (err==0) err = cerr; 1622 out: 1623 return err; 1624 1625 out_nfserr: 1626 err = nfserrno(host_err); 1627 goto out; 1628 } 1629 1630 /* 1631 * Create a hardlink 1632 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1633 */ 1634 __be32 1635 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1636 char *name, int len, struct svc_fh *tfhp) 1637 { 1638 struct dentry *ddir, *dnew, *dold; 1639 struct inode *dirp; 1640 __be32 err; 1641 int host_err; 1642 1643 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); 1644 if (err) 1645 goto out; 1646 err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP); 1647 if (err) 1648 goto out; 1649 1650 err = nfserr_perm; 1651 if (!len) 1652 goto out; 1653 err = nfserr_exist; 1654 if (isdotent(name, len)) 1655 goto out; 1656 1657 fh_lock_nested(ffhp, I_MUTEX_PARENT); 1658 ddir = ffhp->fh_dentry; 1659 dirp = ddir->d_inode; 1660 1661 dnew = lookup_one_len(name, ddir, len); 1662 host_err = PTR_ERR(dnew); 1663 if (IS_ERR(dnew)) 1664 goto out_nfserr; 1665 1666 dold = tfhp->fh_dentry; 1667 1668 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt); 1669 if (host_err) { 1670 err = nfserrno(host_err); 1671 goto out_dput; 1672 } 1673 host_err = vfs_link(dold, dirp, dnew); 1674 if (!host_err) { 1675 err = nfserrno(commit_metadata(ffhp)); 1676 if (!err) 1677 err = nfserrno(commit_metadata(tfhp)); 1678 } else { 1679 if (host_err == -EXDEV && rqstp->rq_vers == 2) 1680 err = nfserr_acces; 1681 else 1682 err = nfserrno(host_err); 1683 } 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 if (svc_msnfs(ffhp) && 1759 ((odentry->d_count > 1) || (ndentry->d_count > 1))) { 1760 host_err = -EPERM; 1761 goto out_dput_new; 1762 } 1763 1764 host_err = -EXDEV; 1765 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) 1766 goto out_dput_new; 1767 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt); 1768 if (host_err) 1769 goto out_dput_new; 1770 1771 host_err = vfs_rename(fdir, odentry, tdir, ndentry); 1772 if (!host_err) { 1773 host_err = commit_metadata(tfhp); 1774 if (!host_err) 1775 host_err = commit_metadata(ffhp); 1776 } 1777 1778 mnt_drop_write(ffhp->fh_export->ex_path.mnt); 1779 1780 out_dput_new: 1781 dput(ndentry); 1782 out_dput_old: 1783 dput(odentry); 1784 out_nfserr: 1785 err = nfserrno(host_err); 1786 1787 /* we cannot reply on fh_unlock on the two filehandles, 1788 * as that would do the wrong thing if the two directories 1789 * were the same, so again we do it by hand 1790 */ 1791 fill_post_wcc(ffhp); 1792 fill_post_wcc(tfhp); 1793 unlock_rename(tdentry, fdentry); 1794 ffhp->fh_locked = tfhp->fh_locked = 0; 1795 1796 out: 1797 return err; 1798 } 1799 1800 /* 1801 * Unlink a file or directory 1802 * N.B. After this call fhp needs an fh_put 1803 */ 1804 __be32 1805 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1806 char *fname, int flen) 1807 { 1808 struct dentry *dentry, *rdentry; 1809 struct inode *dirp; 1810 __be32 err; 1811 int host_err; 1812 1813 err = nfserr_acces; 1814 if (!flen || isdotent(fname, flen)) 1815 goto out; 1816 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); 1817 if (err) 1818 goto out; 1819 1820 fh_lock_nested(fhp, I_MUTEX_PARENT); 1821 dentry = fhp->fh_dentry; 1822 dirp = dentry->d_inode; 1823 1824 rdentry = lookup_one_len(fname, dentry, flen); 1825 host_err = PTR_ERR(rdentry); 1826 if (IS_ERR(rdentry)) 1827 goto out_nfserr; 1828 1829 if (!rdentry->d_inode) { 1830 dput(rdentry); 1831 err = nfserr_noent; 1832 goto out; 1833 } 1834 1835 if (!type) 1836 type = rdentry->d_inode->i_mode & S_IFMT; 1837 1838 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1839 if (host_err) 1840 goto out_nfserr; 1841 1842 if (type != S_IFDIR) { /* It's UNLINK */ 1843 #ifdef MSNFS 1844 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1845 (rdentry->d_count > 1)) { 1846 host_err = -EPERM; 1847 } else 1848 #endif 1849 host_err = vfs_unlink(dirp, rdentry); 1850 } else { /* It's RMDIR */ 1851 host_err = vfs_rmdir(dirp, rdentry); 1852 } 1853 1854 dput(rdentry); 1855 1856 if (!host_err) 1857 host_err = commit_metadata(fhp); 1858 1859 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1860 out_nfserr: 1861 err = nfserrno(host_err); 1862 out: 1863 return err; 1864 } 1865 1866 /* 1867 * We do this buffering because we must not call back into the file 1868 * system's ->lookup() method from the filldir callback. That may well 1869 * deadlock a number of file systems. 1870 * 1871 * This is based heavily on the implementation of same in XFS. 1872 */ 1873 struct buffered_dirent { 1874 u64 ino; 1875 loff_t offset; 1876 int namlen; 1877 unsigned int d_type; 1878 char name[]; 1879 }; 1880 1881 struct readdir_data { 1882 char *dirent; 1883 size_t used; 1884 int full; 1885 }; 1886 1887 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, 1888 loff_t offset, u64 ino, unsigned int d_type) 1889 { 1890 struct readdir_data *buf = __buf; 1891 struct buffered_dirent *de = (void *)(buf->dirent + buf->used); 1892 unsigned int reclen; 1893 1894 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); 1895 if (buf->used + reclen > PAGE_SIZE) { 1896 buf->full = 1; 1897 return -EINVAL; 1898 } 1899 1900 de->namlen = namlen; 1901 de->offset = offset; 1902 de->ino = ino; 1903 de->d_type = d_type; 1904 memcpy(de->name, name, namlen); 1905 buf->used += reclen; 1906 1907 return 0; 1908 } 1909 1910 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, 1911 struct readdir_cd *cdp, loff_t *offsetp) 1912 { 1913 struct readdir_data buf; 1914 struct buffered_dirent *de; 1915 int host_err; 1916 int size; 1917 loff_t offset; 1918 1919 buf.dirent = (void *)__get_free_page(GFP_KERNEL); 1920 if (!buf.dirent) 1921 return nfserrno(-ENOMEM); 1922 1923 offset = *offsetp; 1924 1925 while (1) { 1926 struct inode *dir_inode = file->f_path.dentry->d_inode; 1927 unsigned int reclen; 1928 1929 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1930 buf.used = 0; 1931 buf.full = 0; 1932 1933 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf); 1934 if (buf.full) 1935 host_err = 0; 1936 1937 if (host_err < 0) 1938 break; 1939 1940 size = buf.used; 1941 1942 if (!size) 1943 break; 1944 1945 /* 1946 * Various filldir functions may end up calling back into 1947 * lookup_one_len() and the file system's ->lookup() method. 1948 * These expect i_mutex to be held, as it would within readdir. 1949 */ 1950 host_err = mutex_lock_killable(&dir_inode->i_mutex); 1951 if (host_err) 1952 break; 1953 1954 de = (struct buffered_dirent *)buf.dirent; 1955 while (size > 0) { 1956 offset = de->offset; 1957 1958 if (func(cdp, de->name, de->namlen, de->offset, 1959 de->ino, de->d_type)) 1960 break; 1961 1962 if (cdp->err != nfs_ok) 1963 break; 1964 1965 reclen = ALIGN(sizeof(*de) + de->namlen, 1966 sizeof(u64)); 1967 size -= reclen; 1968 de = (struct buffered_dirent *)((char *)de + reclen); 1969 } 1970 mutex_unlock(&dir_inode->i_mutex); 1971 if (size > 0) /* We bailed out early */ 1972 break; 1973 1974 offset = vfs_llseek(file, 0, SEEK_CUR); 1975 } 1976 1977 free_page((unsigned long)(buf.dirent)); 1978 1979 if (host_err) 1980 return nfserrno(host_err); 1981 1982 *offsetp = offset; 1983 return cdp->err; 1984 } 1985 1986 /* 1987 * Read entries from a directory. 1988 * The NFSv3/4 verifier we ignore for now. 1989 */ 1990 __be32 1991 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 1992 struct readdir_cd *cdp, filldir_t func) 1993 { 1994 __be32 err; 1995 struct file *file; 1996 loff_t offset = *offsetp; 1997 1998 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file); 1999 if (err) 2000 goto out; 2001 2002 offset = vfs_llseek(file, offset, 0); 2003 if (offset < 0) { 2004 err = nfserrno((int)offset); 2005 goto out_close; 2006 } 2007 2008 err = nfsd_buffered_readdir(file, func, cdp, offsetp); 2009 2010 if (err == nfserr_eof || err == nfserr_toosmall) 2011 err = nfs_ok; /* can still be found in ->err */ 2012 out_close: 2013 nfsd_close(file); 2014 out: 2015 return err; 2016 } 2017 2018 /* 2019 * Get file system stats 2020 * N.B. After this call fhp needs an fh_put 2021 */ 2022 __be32 2023 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) 2024 { 2025 __be32 err; 2026 2027 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); 2028 if (!err) { 2029 struct path path = { 2030 .mnt = fhp->fh_export->ex_path.mnt, 2031 .dentry = fhp->fh_dentry, 2032 }; 2033 if (vfs_statfs(&path, stat)) 2034 err = nfserr_io; 2035 } 2036 return err; 2037 } 2038 2039 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) 2040 { 2041 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; 2042 } 2043 2044 /* 2045 * Check for a user's access permissions to this inode. 2046 */ 2047 __be32 2048 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, 2049 struct dentry *dentry, int acc) 2050 { 2051 struct inode *inode = dentry->d_inode; 2052 int err; 2053 2054 if (acc == NFSD_MAY_NOP) 2055 return 0; 2056 #if 0 2057 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 2058 acc, 2059 (acc & NFSD_MAY_READ)? " read" : "", 2060 (acc & NFSD_MAY_WRITE)? " write" : "", 2061 (acc & NFSD_MAY_EXEC)? " exec" : "", 2062 (acc & NFSD_MAY_SATTR)? " sattr" : "", 2063 (acc & NFSD_MAY_TRUNC)? " trunc" : "", 2064 (acc & NFSD_MAY_LOCK)? " lock" : "", 2065 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", 2066 inode->i_mode, 2067 IS_IMMUTABLE(inode)? " immut" : "", 2068 IS_APPEND(inode)? " append" : "", 2069 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); 2070 dprintk(" owner %d/%d user %d/%d\n", 2071 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); 2072 #endif 2073 2074 /* Normally we reject any write/sattr etc access on a read-only file 2075 * system. But if it is IRIX doing check on write-access for a 2076 * device special file, we ignore rofs. 2077 */ 2078 if (!(acc & NFSD_MAY_LOCAL_ACCESS)) 2079 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { 2080 if (exp_rdonly(rqstp, exp) || 2081 __mnt_is_readonly(exp->ex_path.mnt)) 2082 return nfserr_rofs; 2083 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) 2084 return nfserr_perm; 2085 } 2086 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) 2087 return nfserr_perm; 2088 2089 if (acc & NFSD_MAY_LOCK) { 2090 /* If we cannot rely on authentication in NLM requests, 2091 * just allow locks, otherwise require read permission, or 2092 * ownership 2093 */ 2094 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 2095 return 0; 2096 else 2097 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE; 2098 } 2099 /* 2100 * The file owner always gets access permission for accesses that 2101 * would normally be checked at open time. This is to make 2102 * file access work even when the client has done a fchmod(fd, 0). 2103 * 2104 * However, `cp foo bar' should fail nevertheless when bar is 2105 * readonly. A sensible way to do this might be to reject all 2106 * attempts to truncate a read-only file, because a creat() call 2107 * always implies file truncation. 2108 * ... but this isn't really fair. A process may reasonably call 2109 * ftruncate on an open file descriptor on a file with perm 000. 2110 * We must trust the client to do permission checking - using "ACCESS" 2111 * with NFSv3. 2112 */ 2113 if ((acc & NFSD_MAY_OWNER_OVERRIDE) && 2114 inode->i_uid == current_fsuid()) 2115 return 0; 2116 2117 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ 2118 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); 2119 2120 /* Allow read access to binaries even when mode 111 */ 2121 if (err == -EACCES && S_ISREG(inode->i_mode) && 2122 acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE)) 2123 err = inode_permission(inode, MAY_EXEC); 2124 2125 return err? nfserrno(err) : 0; 2126 } 2127 2128 void 2129 nfsd_racache_shutdown(void) 2130 { 2131 struct raparms *raparm, *last_raparm; 2132 unsigned int i; 2133 2134 dprintk("nfsd: freeing readahead buffers.\n"); 2135 2136 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2137 raparm = raparm_hash[i].pb_head; 2138 while(raparm) { 2139 last_raparm = raparm; 2140 raparm = raparm->p_next; 2141 kfree(last_raparm); 2142 } 2143 raparm_hash[i].pb_head = NULL; 2144 } 2145 } 2146 /* 2147 * Initialize readahead param cache 2148 */ 2149 int 2150 nfsd_racache_init(int cache_size) 2151 { 2152 int i; 2153 int j = 0; 2154 int nperbucket; 2155 struct raparms **raparm = NULL; 2156 2157 2158 if (raparm_hash[0].pb_head) 2159 return 0; 2160 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE); 2161 if (nperbucket < 2) 2162 nperbucket = 2; 2163 cache_size = nperbucket * RAPARM_HASH_SIZE; 2164 2165 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); 2166 2167 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2168 spin_lock_init(&raparm_hash[i].pb_lock); 2169 2170 raparm = &raparm_hash[i].pb_head; 2171 for (j = 0; j < nperbucket; j++) { 2172 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL); 2173 if (!*raparm) 2174 goto out_nomem; 2175 raparm = &(*raparm)->p_next; 2176 } 2177 *raparm = NULL; 2178 } 2179 2180 nfsdstats.ra_size = cache_size; 2181 return 0; 2182 2183 out_nomem: 2184 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n"); 2185 nfsd_racache_shutdown(); 2186 return -ENOMEM; 2187 } 2188 2189 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 2190 struct posix_acl * 2191 nfsd_get_posix_acl(struct svc_fh *fhp, int type) 2192 { 2193 struct inode *inode = fhp->fh_dentry->d_inode; 2194 char *name; 2195 void *value = NULL; 2196 ssize_t size; 2197 struct posix_acl *acl; 2198 2199 if (!IS_POSIXACL(inode)) 2200 return ERR_PTR(-EOPNOTSUPP); 2201 2202 switch (type) { 2203 case ACL_TYPE_ACCESS: 2204 name = POSIX_ACL_XATTR_ACCESS; 2205 break; 2206 case ACL_TYPE_DEFAULT: 2207 name = POSIX_ACL_XATTR_DEFAULT; 2208 break; 2209 default: 2210 return ERR_PTR(-EOPNOTSUPP); 2211 } 2212 2213 size = nfsd_getxattr(fhp->fh_dentry, name, &value); 2214 if (size < 0) 2215 return ERR_PTR(size); 2216 2217 acl = posix_acl_from_xattr(value, size); 2218 kfree(value); 2219 return acl; 2220 } 2221 2222 int 2223 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) 2224 { 2225 struct inode *inode = fhp->fh_dentry->d_inode; 2226 char *name; 2227 void *value = NULL; 2228 size_t size; 2229 int error; 2230 2231 if (!IS_POSIXACL(inode) || 2232 !inode->i_op->setxattr || !inode->i_op->removexattr) 2233 return -EOPNOTSUPP; 2234 switch(type) { 2235 case ACL_TYPE_ACCESS: 2236 name = POSIX_ACL_XATTR_ACCESS; 2237 break; 2238 case ACL_TYPE_DEFAULT: 2239 name = POSIX_ACL_XATTR_DEFAULT; 2240 break; 2241 default: 2242 return -EOPNOTSUPP; 2243 } 2244 2245 if (acl && acl->a_count) { 2246 size = posix_acl_xattr_size(acl->a_count); 2247 value = kmalloc(size, GFP_KERNEL); 2248 if (!value) 2249 return -ENOMEM; 2250 error = posix_acl_to_xattr(acl, value, size); 2251 if (error < 0) 2252 goto getout; 2253 size = error; 2254 } else 2255 size = 0; 2256 2257 error = mnt_want_write(fhp->fh_export->ex_path.mnt); 2258 if (error) 2259 goto getout; 2260 if (size) 2261 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); 2262 else { 2263 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) 2264 error = 0; 2265 else { 2266 error = vfs_removexattr(fhp->fh_dentry, name); 2267 if (error == -ENODATA) 2268 error = 0; 2269 } 2270 } 2271 mnt_drop_write(fhp->fh_export->ex_path.mnt); 2272 2273 getout: 2274 kfree(value); 2275 return error; 2276 } 2277 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 2278