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 int error = 0; 285 286 if (!EX_ISSYNC(fhp->fh_export)) 287 return 0; 288 289 if (export_ops->commit_metadata) { 290 error = export_ops->commit_metadata(inode); 291 } else { 292 struct writeback_control wbc = { 293 .sync_mode = WB_SYNC_ALL, 294 .nr_to_write = 0, /* metadata only */ 295 }; 296 297 error = sync_inode(inode, &wbc); 298 } 299 300 return error; 301 } 302 303 /* 304 * Set various file attributes. 305 * N.B. After this call fhp needs an fh_put 306 */ 307 __be32 308 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 309 int check_guard, time_t guardtime) 310 { 311 struct dentry *dentry; 312 struct inode *inode; 313 int accmode = NFSD_MAY_SATTR; 314 int ftype = 0; 315 __be32 err; 316 int host_err; 317 int size_change = 0; 318 319 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 320 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; 321 if (iap->ia_valid & ATTR_SIZE) 322 ftype = S_IFREG; 323 324 /* Get inode */ 325 err = fh_verify(rqstp, fhp, ftype, accmode); 326 if (err) 327 goto out; 328 329 dentry = fhp->fh_dentry; 330 inode = dentry->d_inode; 331 332 /* Ignore any mode updates on symlinks */ 333 if (S_ISLNK(inode->i_mode)) 334 iap->ia_valid &= ~ATTR_MODE; 335 336 if (!iap->ia_valid) 337 goto out; 338 339 /* 340 * NFSv2 does not differentiate between "set-[ac]time-to-now" 341 * which only requires access, and "set-[ac]time-to-X" which 342 * requires ownership. 343 * So if it looks like it might be "set both to the same time which 344 * is close to now", and if inode_change_ok fails, then we 345 * convert to "set to now" instead of "set to explicit time" 346 * 347 * We only call inode_change_ok as the last test as technically 348 * it is not an interface that we should be using. It is only 349 * valid if the filesystem does not define it's own i_op->setattr. 350 */ 351 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 352 #define MAX_TOUCH_TIME_ERROR (30*60) 353 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && 354 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) { 355 /* 356 * Looks probable. 357 * 358 * Now just make sure time is in the right ballpark. 359 * Solaris, at least, doesn't seem to care what the time 360 * request is. We require it be within 30 minutes of now. 361 */ 362 time_t delta = iap->ia_atime.tv_sec - get_seconds(); 363 if (delta < 0) 364 delta = -delta; 365 if (delta < MAX_TOUCH_TIME_ERROR && 366 inode_change_ok(inode, iap) != 0) { 367 /* 368 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME. 369 * This will cause notify_change to set these times 370 * to "now" 371 */ 372 iap->ia_valid &= ~BOTH_TIME_SET; 373 } 374 } 375 376 /* 377 * The size case is special. 378 * It changes the file as well as the attributes. 379 */ 380 if (iap->ia_valid & ATTR_SIZE) { 381 if (iap->ia_size < inode->i_size) { 382 err = nfsd_permission(rqstp, fhp->fh_export, dentry, 383 NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE); 384 if (err) 385 goto out; 386 } 387 388 /* 389 * If we are changing the size of the file, then 390 * we need to break all leases. 391 */ 392 host_err = break_lease(inode, O_WRONLY | O_NONBLOCK); 393 if (host_err == -EWOULDBLOCK) 394 host_err = -ETIMEDOUT; 395 if (host_err) /* ENOMEM or EWOULDBLOCK */ 396 goto out_nfserr; 397 398 host_err = get_write_access(inode); 399 if (host_err) 400 goto out_nfserr; 401 402 size_change = 1; 403 host_err = locks_verify_truncate(inode, NULL, iap->ia_size); 404 if (host_err) { 405 put_write_access(inode); 406 goto out_nfserr; 407 } 408 } 409 410 /* sanitize the mode change */ 411 if (iap->ia_valid & ATTR_MODE) { 412 iap->ia_mode &= S_IALLUGO; 413 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); 414 } 415 416 /* Revoke setuid/setgid on chown */ 417 if (!S_ISDIR(inode->i_mode) && 418 (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) || 419 ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) { 420 iap->ia_valid |= ATTR_KILL_PRIV; 421 if (iap->ia_valid & ATTR_MODE) { 422 /* we're setting mode too, just clear the s*id bits */ 423 iap->ia_mode &= ~S_ISUID; 424 if (iap->ia_mode & S_IXGRP) 425 iap->ia_mode &= ~S_ISGID; 426 } else { 427 /* set ATTR_KILL_* bits and let VFS handle it */ 428 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID); 429 } 430 } 431 432 /* Change the attributes. */ 433 434 iap->ia_valid |= ATTR_CTIME; 435 436 err = nfserr_notsync; 437 if (!check_guard || guardtime == inode->i_ctime.tv_sec) { 438 fh_lock(fhp); 439 host_err = notify_change(dentry, iap); 440 err = nfserrno(host_err); 441 fh_unlock(fhp); 442 } 443 if (size_change) 444 put_write_access(inode); 445 if (!err) 446 commit_metadata(fhp); 447 out: 448 return err; 449 450 out_nfserr: 451 err = nfserrno(host_err); 452 goto out; 453 } 454 455 #if defined(CONFIG_NFSD_V2_ACL) || \ 456 defined(CONFIG_NFSD_V3_ACL) || \ 457 defined(CONFIG_NFSD_V4) 458 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf) 459 { 460 ssize_t buflen; 461 ssize_t ret; 462 463 buflen = vfs_getxattr(dentry, key, NULL, 0); 464 if (buflen <= 0) 465 return buflen; 466 467 *buf = kmalloc(buflen, GFP_KERNEL); 468 if (!*buf) 469 return -ENOMEM; 470 471 ret = vfs_getxattr(dentry, key, *buf, buflen); 472 if (ret < 0) 473 kfree(*buf); 474 return ret; 475 } 476 #endif 477 478 #if defined(CONFIG_NFSD_V4) 479 static int 480 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key) 481 { 482 int len; 483 size_t buflen; 484 char *buf = NULL; 485 int error = 0; 486 487 buflen = posix_acl_xattr_size(pacl->a_count); 488 buf = kmalloc(buflen, GFP_KERNEL); 489 error = -ENOMEM; 490 if (buf == NULL) 491 goto out; 492 493 len = posix_acl_to_xattr(pacl, buf, buflen); 494 if (len < 0) { 495 error = len; 496 goto out; 497 } 498 499 error = vfs_setxattr(dentry, key, buf, len, 0); 500 out: 501 kfree(buf); 502 return error; 503 } 504 505 __be32 506 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 507 struct nfs4_acl *acl) 508 { 509 __be32 error; 510 int host_error; 511 struct dentry *dentry; 512 struct inode *inode; 513 struct posix_acl *pacl = NULL, *dpacl = NULL; 514 unsigned int flags = 0; 515 516 /* Get inode */ 517 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); 518 if (error) 519 return error; 520 521 dentry = fhp->fh_dentry; 522 inode = dentry->d_inode; 523 if (S_ISDIR(inode->i_mode)) 524 flags = NFS4_ACL_DIR; 525 526 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 527 if (host_error == -EINVAL) { 528 return nfserr_attrnotsupp; 529 } else if (host_error < 0) 530 goto out_nfserr; 531 532 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); 533 if (host_error < 0) 534 goto out_release; 535 536 if (S_ISDIR(inode->i_mode)) 537 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); 538 539 out_release: 540 posix_acl_release(pacl); 541 posix_acl_release(dpacl); 542 out_nfserr: 543 if (host_error == -EOPNOTSUPP) 544 return nfserr_attrnotsupp; 545 else 546 return nfserrno(host_error); 547 } 548 549 static struct posix_acl * 550 _get_posix_acl(struct dentry *dentry, char *key) 551 { 552 void *buf = NULL; 553 struct posix_acl *pacl = NULL; 554 int buflen; 555 556 buflen = nfsd_getxattr(dentry, key, &buf); 557 if (!buflen) 558 buflen = -ENODATA; 559 if (buflen <= 0) 560 return ERR_PTR(buflen); 561 562 pacl = posix_acl_from_xattr(buf, buflen); 563 kfree(buf); 564 return pacl; 565 } 566 567 int 568 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl) 569 { 570 struct inode *inode = dentry->d_inode; 571 int error = 0; 572 struct posix_acl *pacl = NULL, *dpacl = NULL; 573 unsigned int flags = 0; 574 575 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS); 576 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA) 577 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 578 if (IS_ERR(pacl)) { 579 error = PTR_ERR(pacl); 580 pacl = NULL; 581 goto out; 582 } 583 584 if (S_ISDIR(inode->i_mode)) { 585 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT); 586 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA) 587 dpacl = NULL; 588 else if (IS_ERR(dpacl)) { 589 error = PTR_ERR(dpacl); 590 dpacl = NULL; 591 goto out; 592 } 593 flags = NFS4_ACL_DIR; 594 } 595 596 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags); 597 if (IS_ERR(*acl)) { 598 error = PTR_ERR(*acl); 599 *acl = NULL; 600 } 601 out: 602 posix_acl_release(pacl); 603 posix_acl_release(dpacl); 604 return error; 605 } 606 607 #endif /* defined(CONFIG_NFSD_V4) */ 608 609 #ifdef CONFIG_NFSD_V3 610 /* 611 * Check server access rights to a file system object 612 */ 613 struct accessmap { 614 u32 access; 615 int how; 616 }; 617 static struct accessmap nfs3_regaccess[] = { 618 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 619 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 620 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, 621 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, 622 623 { 0, 0 } 624 }; 625 626 static struct accessmap nfs3_diraccess[] = { 627 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 628 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, 629 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, 630 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, 631 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, 632 633 { 0, 0 } 634 }; 635 636 static struct accessmap nfs3_anyaccess[] = { 637 /* Some clients - Solaris 2.6 at least, make an access call 638 * to the server to check for access for things like /dev/null 639 * (which really, the server doesn't care about). So 640 * We provide simple access checking for them, looking 641 * mainly at mode bits, and we make sure to ignore read-only 642 * filesystem checks 643 */ 644 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 645 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 646 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 647 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 648 649 { 0, 0 } 650 }; 651 652 __be32 653 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 654 { 655 struct accessmap *map; 656 struct svc_export *export; 657 struct dentry *dentry; 658 u32 query, result = 0, sresult = 0; 659 __be32 error; 660 661 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP); 662 if (error) 663 goto out; 664 665 export = fhp->fh_export; 666 dentry = fhp->fh_dentry; 667 668 if (S_ISREG(dentry->d_inode->i_mode)) 669 map = nfs3_regaccess; 670 else if (S_ISDIR(dentry->d_inode->i_mode)) 671 map = nfs3_diraccess; 672 else 673 map = nfs3_anyaccess; 674 675 676 query = *access; 677 for (; map->access; map++) { 678 if (map->access & query) { 679 __be32 err2; 680 681 sresult |= map->access; 682 683 err2 = nfsd_permission(rqstp, export, dentry, map->how); 684 switch (err2) { 685 case nfs_ok: 686 result |= map->access; 687 break; 688 689 /* the following error codes just mean the access was not allowed, 690 * rather than an error occurred */ 691 case nfserr_rofs: 692 case nfserr_acces: 693 case nfserr_perm: 694 /* simply don't "or" in the access bit. */ 695 break; 696 default: 697 error = err2; 698 goto out; 699 } 700 } 701 } 702 *access = result; 703 if (supported) 704 *supported = sresult; 705 706 out: 707 return error; 708 } 709 #endif /* CONFIG_NFSD_V3 */ 710 711 712 713 /* 714 * Open an existing file or directory. 715 * The access argument indicates the type of open (read/write/lock) 716 * N.B. After this call fhp needs an fh_put 717 */ 718 __be32 719 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 720 int access, struct file **filp) 721 { 722 struct dentry *dentry; 723 struct inode *inode; 724 int flags = O_RDONLY|O_LARGEFILE; 725 __be32 err; 726 int host_err = 0; 727 728 validate_process_creds(); 729 730 /* 731 * If we get here, then the client has already done an "open", 732 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 733 * in case a chmod has now revoked permission. 734 */ 735 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE); 736 if (err) 737 goto out; 738 739 dentry = fhp->fh_dentry; 740 inode = dentry->d_inode; 741 742 /* Disallow write access to files with the append-only bit set 743 * or any access when mandatory locking enabled 744 */ 745 err = nfserr_perm; 746 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE)) 747 goto out; 748 /* 749 * We must ignore files (but only files) which might have mandatory 750 * locks on them because there is no way to know if the accesser has 751 * the lock. 752 */ 753 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode)) 754 goto out; 755 756 if (!inode->i_fop) 757 goto out; 758 759 /* 760 * Check to see if there are any leases on this file. 761 * This may block while leases are broken. 762 */ 763 if (!(access & NFSD_MAY_NOT_BREAK_LEASE)) 764 host_err = break_lease(inode, O_NONBLOCK | ((access & NFSD_MAY_WRITE) ? O_WRONLY : 0)); 765 if (host_err == -EWOULDBLOCK) 766 host_err = -ETIMEDOUT; 767 if (host_err) /* NOMEM or WOULDBLOCK */ 768 goto out_nfserr; 769 770 if (access & NFSD_MAY_WRITE) { 771 if (access & NFSD_MAY_READ) 772 flags = O_RDWR|O_LARGEFILE; 773 else 774 flags = O_WRONLY|O_LARGEFILE; 775 } 776 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt), 777 flags, current_cred()); 778 if (IS_ERR(*filp)) 779 host_err = PTR_ERR(*filp); 780 else 781 host_err = ima_file_check(*filp, access); 782 out_nfserr: 783 err = nfserrno(host_err); 784 out: 785 validate_process_creds(); 786 return err; 787 } 788 789 /* 790 * Close a file. 791 */ 792 void 793 nfsd_close(struct file *filp) 794 { 795 fput(filp); 796 } 797 798 /* 799 * Obtain the readahead parameters for the file 800 * specified by (dev, ino). 801 */ 802 803 static inline struct raparms * 804 nfsd_get_raparms(dev_t dev, ino_t ino) 805 { 806 struct raparms *ra, **rap, **frap = NULL; 807 int depth = 0; 808 unsigned int hash; 809 struct raparm_hbucket *rab; 810 811 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK; 812 rab = &raparm_hash[hash]; 813 814 spin_lock(&rab->pb_lock); 815 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) { 816 if (ra->p_ino == ino && ra->p_dev == dev) 817 goto found; 818 depth++; 819 if (ra->p_count == 0) 820 frap = rap; 821 } 822 depth = nfsdstats.ra_size*11/10; 823 if (!frap) { 824 spin_unlock(&rab->pb_lock); 825 return NULL; 826 } 827 rap = frap; 828 ra = *frap; 829 ra->p_dev = dev; 830 ra->p_ino = ino; 831 ra->p_set = 0; 832 ra->p_hindex = hash; 833 found: 834 if (rap != &rab->pb_head) { 835 *rap = ra->p_next; 836 ra->p_next = rab->pb_head; 837 rab->pb_head = ra; 838 } 839 ra->p_count++; 840 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 841 spin_unlock(&rab->pb_lock); 842 return ra; 843 } 844 845 /* 846 * Grab and keep cached pages associated with a file in the svc_rqst 847 * so that they can be passed to the network sendmsg/sendpage routines 848 * directly. They will be released after the sending has completed. 849 */ 850 static int 851 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 852 struct splice_desc *sd) 853 { 854 struct svc_rqst *rqstp = sd->u.data; 855 struct page **pp = rqstp->rq_respages + rqstp->rq_resused; 856 struct page *page = buf->page; 857 size_t size; 858 int ret; 859 860 ret = buf->ops->confirm(pipe, buf); 861 if (unlikely(ret)) 862 return ret; 863 864 size = sd->len; 865 866 if (rqstp->rq_res.page_len == 0) { 867 get_page(page); 868 put_page(*pp); 869 *pp = page; 870 rqstp->rq_resused++; 871 rqstp->rq_res.page_base = buf->offset; 872 rqstp->rq_res.page_len = size; 873 } else if (page != pp[-1]) { 874 get_page(page); 875 if (*pp) 876 put_page(*pp); 877 *pp = page; 878 rqstp->rq_resused++; 879 rqstp->rq_res.page_len += size; 880 } else 881 rqstp->rq_res.page_len += size; 882 883 return size; 884 } 885 886 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, 887 struct splice_desc *sd) 888 { 889 return __splice_from_pipe(pipe, sd, nfsd_splice_actor); 890 } 891 892 static inline int svc_msnfs(struct svc_fh *ffhp) 893 { 894 #ifdef MSNFS 895 return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS); 896 #else 897 return 0; 898 #endif 899 } 900 901 static __be32 902 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 903 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 904 { 905 struct inode *inode; 906 mm_segment_t oldfs; 907 __be32 err; 908 int host_err; 909 910 err = nfserr_perm; 911 inode = file->f_path.dentry->d_inode; 912 913 if (svc_msnfs(fhp) && !lock_may_read(inode, offset, *count)) 914 goto out; 915 916 if (file->f_op->splice_read && rqstp->rq_splice_ok) { 917 struct splice_desc sd = { 918 .len = 0, 919 .total_len = *count, 920 .pos = offset, 921 .u.data = rqstp, 922 }; 923 924 rqstp->rq_resused = 1; 925 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); 926 } else { 927 oldfs = get_fs(); 928 set_fs(KERNEL_DS); 929 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 930 set_fs(oldfs); 931 } 932 933 if (host_err >= 0) { 934 nfsdstats.io_read += host_err; 935 *count = host_err; 936 err = 0; 937 fsnotify_access(file); 938 } else 939 err = nfserrno(host_err); 940 out: 941 return err; 942 } 943 944 static void kill_suid(struct dentry *dentry) 945 { 946 struct iattr ia; 947 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; 948 949 mutex_lock(&dentry->d_inode->i_mutex); 950 notify_change(dentry, &ia); 951 mutex_unlock(&dentry->d_inode->i_mutex); 952 } 953 954 /* 955 * Gathered writes: If another process is currently writing to the file, 956 * there's a high chance this is another nfsd (triggered by a bulk write 957 * from a client's biod). Rather than syncing the file with each write 958 * request, we sleep for 10 msec. 959 * 960 * I don't know if this roughly approximates C. Juszak's idea of 961 * gathered writes, but it's a nice and simple solution (IMHO), and it 962 * seems to work:-) 963 * 964 * Note: we do this only in the NFSv2 case, since v3 and higher have a 965 * better tool (separate unstable writes and commits) for solving this 966 * problem. 967 */ 968 static int wait_for_concurrent_writes(struct file *file) 969 { 970 struct inode *inode = file->f_path.dentry->d_inode; 971 static ino_t last_ino; 972 static dev_t last_dev; 973 int err = 0; 974 975 if (atomic_read(&inode->i_writecount) > 1 976 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 977 dprintk("nfsd: write defer %d\n", task_pid_nr(current)); 978 msleep(10); 979 dprintk("nfsd: write resume %d\n", task_pid_nr(current)); 980 } 981 982 if (inode->i_state & I_DIRTY) { 983 dprintk("nfsd: write sync %d\n", task_pid_nr(current)); 984 err = vfs_fsync(file, 0); 985 } 986 last_ino = inode->i_ino; 987 last_dev = inode->i_sb->s_dev; 988 return err; 989 } 990 991 static __be32 992 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 993 loff_t offset, struct kvec *vec, int vlen, 994 unsigned long *cnt, int *stablep) 995 { 996 struct svc_export *exp; 997 struct dentry *dentry; 998 struct inode *inode; 999 mm_segment_t oldfs; 1000 __be32 err = 0; 1001 int host_err; 1002 int stable = *stablep; 1003 int use_wgather; 1004 1005 #ifdef MSNFS 1006 err = nfserr_perm; 1007 1008 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1009 (!lock_may_write(file->f_path.dentry->d_inode, offset, *cnt))) 1010 goto out; 1011 #endif 1012 1013 dentry = file->f_path.dentry; 1014 inode = dentry->d_inode; 1015 exp = fhp->fh_export; 1016 1017 /* 1018 * Request sync writes if 1019 * - the sync export option has been set, or 1020 * - the client requested O_SYNC behavior (NFSv3 feature). 1021 * - The file system doesn't support fsync(). 1022 * When NFSv2 gathered writes have been configured for this volume, 1023 * flushing the data to disk is handled separately below. 1024 */ 1025 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); 1026 1027 if (!file->f_op->fsync) {/* COMMIT3 cannot work */ 1028 stable = 2; 1029 *stablep = 2; /* FILE_SYNC */ 1030 } 1031 1032 if (!EX_ISSYNC(exp)) 1033 stable = 0; 1034 if (stable && !use_wgather) { 1035 spin_lock(&file->f_lock); 1036 file->f_flags |= O_SYNC; 1037 spin_unlock(&file->f_lock); 1038 } 1039 1040 /* Write the data. */ 1041 oldfs = get_fs(); set_fs(KERNEL_DS); 1042 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); 1043 set_fs(oldfs); 1044 if (host_err < 0) 1045 goto out_nfserr; 1046 *cnt = host_err; 1047 nfsdstats.io_write += host_err; 1048 fsnotify_modify(file); 1049 1050 /* clear setuid/setgid flag after write */ 1051 if (inode->i_mode & (S_ISUID | S_ISGID)) 1052 kill_suid(dentry); 1053 1054 if (stable && use_wgather) 1055 host_err = wait_for_concurrent_writes(file); 1056 1057 out_nfserr: 1058 dprintk("nfsd: write complete host_err=%d\n", host_err); 1059 if (host_err >= 0) 1060 err = 0; 1061 else 1062 err = nfserrno(host_err); 1063 out: 1064 return err; 1065 } 1066 1067 /* 1068 * Read data from a file. count must contain the requested read count 1069 * on entry. On return, *count contains the number of bytes actually read. 1070 * N.B. After this call fhp needs an fh_put 1071 */ 1072 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 1073 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 1074 { 1075 struct file *file; 1076 struct inode *inode; 1077 struct raparms *ra; 1078 __be32 err; 1079 1080 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); 1081 if (err) 1082 return err; 1083 1084 inode = file->f_path.dentry->d_inode; 1085 1086 /* Get readahead parameters */ 1087 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 1088 1089 if (ra && ra->p_set) 1090 file->f_ra = ra->p_ra; 1091 1092 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1093 1094 /* Write back readahead params */ 1095 if (ra) { 1096 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex]; 1097 spin_lock(&rab->pb_lock); 1098 ra->p_ra = file->f_ra; 1099 ra->p_set = 1; 1100 ra->p_count--; 1101 spin_unlock(&rab->pb_lock); 1102 } 1103 1104 nfsd_close(file); 1105 return err; 1106 } 1107 1108 /* As above, but use the provided file descriptor. */ 1109 __be32 1110 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1111 loff_t offset, struct kvec *vec, int vlen, 1112 unsigned long *count) 1113 { 1114 __be32 err; 1115 1116 if (file) { 1117 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1118 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE); 1119 if (err) 1120 goto out; 1121 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1122 } else /* Note file may still be NULL in NFSv4 special stateid case: */ 1123 err = nfsd_read(rqstp, fhp, offset, vec, vlen, count); 1124 out: 1125 return err; 1126 } 1127 1128 /* 1129 * Write data to a file. 1130 * The stable flag requests synchronous writes. 1131 * N.B. After this call fhp needs an fh_put 1132 */ 1133 __be32 1134 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1135 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, 1136 int *stablep) 1137 { 1138 __be32 err = 0; 1139 1140 if (file) { 1141 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1142 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE); 1143 if (err) 1144 goto out; 1145 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1146 stablep); 1147 } else { 1148 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); 1149 if (err) 1150 goto out; 1151 1152 if (cnt) 1153 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1154 cnt, stablep); 1155 nfsd_close(file); 1156 } 1157 out: 1158 return err; 1159 } 1160 1161 #ifdef CONFIG_NFSD_V3 1162 /* 1163 * Commit all pending writes to stable storage. 1164 * 1165 * Note: we only guarantee that data that lies within the range specified 1166 * by the 'offset' and 'count' parameters will be synced. 1167 * 1168 * Unfortunately we cannot lock the file to make sure we return full WCC 1169 * data to the client, as locking happens lower down in the filesystem. 1170 */ 1171 __be32 1172 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1173 loff_t offset, unsigned long count) 1174 { 1175 struct file *file; 1176 loff_t end = LLONG_MAX; 1177 __be32 err = nfserr_inval; 1178 1179 if (offset < 0) 1180 goto out; 1181 if (count != 0) { 1182 end = offset + (loff_t)count - 1; 1183 if (end < offset) 1184 goto out; 1185 } 1186 1187 err = nfsd_open(rqstp, fhp, S_IFREG, 1188 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file); 1189 if (err) 1190 goto out; 1191 if (EX_ISSYNC(fhp->fh_export)) { 1192 int err2 = vfs_fsync_range(file, offset, end, 0); 1193 1194 if (err2 != -EINVAL) 1195 err = nfserrno(err2); 1196 else 1197 err = nfserr_notsupp; 1198 } 1199 1200 nfsd_close(file); 1201 out: 1202 return err; 1203 } 1204 #endif /* CONFIG_NFSD_V3 */ 1205 1206 static __be32 1207 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp, 1208 struct iattr *iap) 1209 { 1210 /* 1211 * Mode has already been set earlier in create: 1212 */ 1213 iap->ia_valid &= ~ATTR_MODE; 1214 /* 1215 * Setting uid/gid works only for root. Irix appears to 1216 * send along the gid on create when it tries to implement 1217 * setgid directories via NFS: 1218 */ 1219 if (current_fsuid() != 0) 1220 iap->ia_valid &= ~(ATTR_UID|ATTR_GID); 1221 if (iap->ia_valid) 1222 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1223 return 0; 1224 } 1225 1226 /* HPUX client sometimes creates a file in mode 000, and sets size to 0. 1227 * setting size to 0 may fail for some specific file systems by the permission 1228 * checking which requires WRITE permission but the mode is 000. 1229 * we ignore the resizing(to 0) on the just new created file, since the size is 1230 * 0 after file created. 1231 * 1232 * call this only after vfs_create() is called. 1233 * */ 1234 static void 1235 nfsd_check_ignore_resizing(struct iattr *iap) 1236 { 1237 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) 1238 iap->ia_valid &= ~ATTR_SIZE; 1239 } 1240 1241 /* 1242 * Create a file (regular, directory, device, fifo); UNIX sockets 1243 * not yet implemented. 1244 * If the response fh has been verified, the parent directory should 1245 * already be locked. Note that the parent directory is left locked. 1246 * 1247 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1248 */ 1249 __be32 1250 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1251 char *fname, int flen, struct iattr *iap, 1252 int type, dev_t rdev, struct svc_fh *resfhp) 1253 { 1254 struct dentry *dentry, *dchild = NULL; 1255 struct inode *dirp; 1256 __be32 err; 1257 __be32 err2; 1258 int host_err; 1259 1260 err = nfserr_perm; 1261 if (!flen) 1262 goto out; 1263 err = nfserr_exist; 1264 if (isdotent(fname, flen)) 1265 goto out; 1266 1267 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1268 if (err) 1269 goto out; 1270 1271 dentry = fhp->fh_dentry; 1272 dirp = dentry->d_inode; 1273 1274 err = nfserr_notdir; 1275 if (!dirp->i_op->lookup) 1276 goto out; 1277 /* 1278 * Check whether the response file handle has been verified yet. 1279 * If it has, the parent directory should already be locked. 1280 */ 1281 if (!resfhp->fh_dentry) { 1282 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1283 fh_lock_nested(fhp, I_MUTEX_PARENT); 1284 dchild = lookup_one_len(fname, dentry, flen); 1285 host_err = PTR_ERR(dchild); 1286 if (IS_ERR(dchild)) 1287 goto out_nfserr; 1288 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1289 if (err) 1290 goto out; 1291 } else { 1292 /* called from nfsd_proc_create */ 1293 dchild = dget(resfhp->fh_dentry); 1294 if (!fhp->fh_locked) { 1295 /* not actually possible */ 1296 printk(KERN_ERR 1297 "nfsd_create: parent %s/%s not locked!\n", 1298 dentry->d_parent->d_name.name, 1299 dentry->d_name.name); 1300 err = nfserr_io; 1301 goto out; 1302 } 1303 } 1304 /* 1305 * Make sure the child dentry is still negative ... 1306 */ 1307 err = nfserr_exist; 1308 if (dchild->d_inode) { 1309 dprintk("nfsd_create: dentry %s/%s not negative!\n", 1310 dentry->d_name.name, dchild->d_name.name); 1311 goto out; 1312 } 1313 1314 if (!(iap->ia_valid & ATTR_MODE)) 1315 iap->ia_mode = 0; 1316 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1317 1318 err = nfserr_inval; 1319 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) { 1320 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", 1321 type); 1322 goto out; 1323 } 1324 1325 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1326 if (host_err) 1327 goto out_nfserr; 1328 1329 /* 1330 * Get the dir op function pointer. 1331 */ 1332 err = 0; 1333 switch (type) { 1334 case S_IFREG: 1335 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1336 if (!host_err) 1337 nfsd_check_ignore_resizing(iap); 1338 break; 1339 case S_IFDIR: 1340 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1341 break; 1342 case S_IFCHR: 1343 case S_IFBLK: 1344 case S_IFIFO: 1345 case S_IFSOCK: 1346 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1347 break; 1348 } 1349 if (host_err < 0) { 1350 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1351 goto out_nfserr; 1352 } 1353 1354 err = nfsd_create_setattr(rqstp, resfhp, iap); 1355 1356 /* 1357 * nfsd_setattr already committed the child. Transactional filesystems 1358 * had a chance to commit changes for both parent and child 1359 * simultaneously making the following commit_metadata a noop. 1360 */ 1361 err2 = nfserrno(commit_metadata(fhp)); 1362 if (err2) 1363 err = err2; 1364 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1365 /* 1366 * Update the file handle to get the new inode info. 1367 */ 1368 if (!err) 1369 err = fh_update(resfhp); 1370 out: 1371 if (dchild && !IS_ERR(dchild)) 1372 dput(dchild); 1373 return err; 1374 1375 out_nfserr: 1376 err = nfserrno(host_err); 1377 goto out; 1378 } 1379 1380 #ifdef CONFIG_NFSD_V3 1381 /* 1382 * NFSv3 version of nfsd_create 1383 */ 1384 __be32 1385 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, 1386 char *fname, int flen, struct iattr *iap, 1387 struct svc_fh *resfhp, int createmode, u32 *verifier, 1388 int *truncp, int *created) 1389 { 1390 struct dentry *dentry, *dchild = NULL; 1391 struct inode *dirp; 1392 __be32 err; 1393 int host_err; 1394 __u32 v_mtime=0, v_atime=0; 1395 1396 err = nfserr_perm; 1397 if (!flen) 1398 goto out; 1399 err = nfserr_exist; 1400 if (isdotent(fname, flen)) 1401 goto out; 1402 if (!(iap->ia_valid & ATTR_MODE)) 1403 iap->ia_mode = 0; 1404 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1405 if (err) 1406 goto out; 1407 1408 dentry = fhp->fh_dentry; 1409 dirp = dentry->d_inode; 1410 1411 /* Get all the sanity checks out of the way before 1412 * we lock the parent. */ 1413 err = nfserr_notdir; 1414 if (!dirp->i_op->lookup) 1415 goto out; 1416 fh_lock_nested(fhp, I_MUTEX_PARENT); 1417 1418 /* 1419 * Compose the response file handle. 1420 */ 1421 dchild = lookup_one_len(fname, dentry, flen); 1422 host_err = PTR_ERR(dchild); 1423 if (IS_ERR(dchild)) 1424 goto out_nfserr; 1425 1426 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1427 if (err) 1428 goto out; 1429 1430 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1431 /* solaris7 gets confused (bugid 4218508) if these have 1432 * the high bit set, so just clear the high bits. If this is 1433 * ever changed to use different attrs for storing the 1434 * verifier, then do_open_lookup() will also need to be fixed 1435 * accordingly. 1436 */ 1437 v_mtime = verifier[0]&0x7fffffff; 1438 v_atime = verifier[1]&0x7fffffff; 1439 } 1440 1441 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1442 if (host_err) 1443 goto out_nfserr; 1444 if (dchild->d_inode) { 1445 err = 0; 1446 1447 switch (createmode) { 1448 case NFS3_CREATE_UNCHECKED: 1449 if (! S_ISREG(dchild->d_inode->i_mode)) 1450 err = nfserr_exist; 1451 else if (truncp) { 1452 /* in nfsv4, we need to treat this case a little 1453 * differently. we don't want to truncate the 1454 * file now; this would be wrong if the OPEN 1455 * fails for some other reason. furthermore, 1456 * if the size is nonzero, we should ignore it 1457 * according to spec! 1458 */ 1459 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1460 } 1461 else { 1462 iap->ia_valid &= ATTR_SIZE; 1463 goto set_attr; 1464 } 1465 break; 1466 case NFS3_CREATE_EXCLUSIVE: 1467 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1468 && dchild->d_inode->i_atime.tv_sec == v_atime 1469 && dchild->d_inode->i_size == 0 ) 1470 break; 1471 /* fallthru */ 1472 case NFS3_CREATE_GUARDED: 1473 err = nfserr_exist; 1474 } 1475 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1476 goto out; 1477 } 1478 1479 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1480 if (host_err < 0) { 1481 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1482 goto out_nfserr; 1483 } 1484 if (created) 1485 *created = 1; 1486 1487 nfsd_check_ignore_resizing(iap); 1488 1489 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1490 /* Cram the verifier into atime/mtime */ 1491 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1492 | ATTR_MTIME_SET|ATTR_ATIME_SET; 1493 /* XXX someone who knows this better please fix it for nsec */ 1494 iap->ia_mtime.tv_sec = v_mtime; 1495 iap->ia_atime.tv_sec = v_atime; 1496 iap->ia_mtime.tv_nsec = 0; 1497 iap->ia_atime.tv_nsec = 0; 1498 } 1499 1500 set_attr: 1501 err = nfsd_create_setattr(rqstp, resfhp, iap); 1502 1503 /* 1504 * nfsd_setattr already committed the child (and possibly also the parent). 1505 */ 1506 if (!err) 1507 err = nfserrno(commit_metadata(fhp)); 1508 1509 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1510 /* 1511 * Update the filehandle to get the new inode info. 1512 */ 1513 if (!err) 1514 err = fh_update(resfhp); 1515 1516 out: 1517 fh_unlock(fhp); 1518 if (dchild && !IS_ERR(dchild)) 1519 dput(dchild); 1520 return err; 1521 1522 out_nfserr: 1523 err = nfserrno(host_err); 1524 goto out; 1525 } 1526 #endif /* CONFIG_NFSD_V3 */ 1527 1528 /* 1529 * Read a symlink. On entry, *lenp must contain the maximum path length that 1530 * fits into the buffer. On return, it contains the true length. 1531 * N.B. After this call fhp needs an fh_put 1532 */ 1533 __be32 1534 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1535 { 1536 struct dentry *dentry; 1537 struct inode *inode; 1538 mm_segment_t oldfs; 1539 __be32 err; 1540 int host_err; 1541 1542 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); 1543 if (err) 1544 goto out; 1545 1546 dentry = fhp->fh_dentry; 1547 inode = dentry->d_inode; 1548 1549 err = nfserr_inval; 1550 if (!inode->i_op->readlink) 1551 goto out; 1552 1553 touch_atime(fhp->fh_export->ex_path.mnt, dentry); 1554 /* N.B. Why does this call need a get_fs()?? 1555 * Remove the set_fs and watch the fireworks:-) --okir 1556 */ 1557 1558 oldfs = get_fs(); set_fs(KERNEL_DS); 1559 host_err = inode->i_op->readlink(dentry, buf, *lenp); 1560 set_fs(oldfs); 1561 1562 if (host_err < 0) 1563 goto out_nfserr; 1564 *lenp = host_err; 1565 err = 0; 1566 out: 1567 return err; 1568 1569 out_nfserr: 1570 err = nfserrno(host_err); 1571 goto out; 1572 } 1573 1574 /* 1575 * Create a symlink and look up its inode 1576 * N.B. After this call _both_ fhp and resfhp need an fh_put 1577 */ 1578 __be32 1579 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1580 char *fname, int flen, 1581 char *path, int plen, 1582 struct svc_fh *resfhp, 1583 struct iattr *iap) 1584 { 1585 struct dentry *dentry, *dnew; 1586 __be32 err, cerr; 1587 int host_err; 1588 1589 err = nfserr_noent; 1590 if (!flen || !plen) 1591 goto out; 1592 err = nfserr_exist; 1593 if (isdotent(fname, flen)) 1594 goto out; 1595 1596 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1597 if (err) 1598 goto out; 1599 fh_lock(fhp); 1600 dentry = fhp->fh_dentry; 1601 dnew = lookup_one_len(fname, dentry, flen); 1602 host_err = PTR_ERR(dnew); 1603 if (IS_ERR(dnew)) 1604 goto out_nfserr; 1605 1606 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1607 if (host_err) 1608 goto out_nfserr; 1609 1610 if (unlikely(path[plen] != 0)) { 1611 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1612 if (path_alloced == NULL) 1613 host_err = -ENOMEM; 1614 else { 1615 strncpy(path_alloced, path, plen); 1616 path_alloced[plen] = 0; 1617 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced); 1618 kfree(path_alloced); 1619 } 1620 } else 1621 host_err = vfs_symlink(dentry->d_inode, dnew, path); 1622 err = nfserrno(host_err); 1623 if (!err) 1624 err = nfserrno(commit_metadata(fhp)); 1625 fh_unlock(fhp); 1626 1627 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1628 1629 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1630 dput(dnew); 1631 if (err==0) err = cerr; 1632 out: 1633 return err; 1634 1635 out_nfserr: 1636 err = nfserrno(host_err); 1637 goto out; 1638 } 1639 1640 /* 1641 * Create a hardlink 1642 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1643 */ 1644 __be32 1645 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1646 char *name, int len, struct svc_fh *tfhp) 1647 { 1648 struct dentry *ddir, *dnew, *dold; 1649 struct inode *dirp; 1650 __be32 err; 1651 int host_err; 1652 1653 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); 1654 if (err) 1655 goto out; 1656 err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP); 1657 if (err) 1658 goto out; 1659 1660 err = nfserr_perm; 1661 if (!len) 1662 goto out; 1663 err = nfserr_exist; 1664 if (isdotent(name, len)) 1665 goto out; 1666 1667 fh_lock_nested(ffhp, I_MUTEX_PARENT); 1668 ddir = ffhp->fh_dentry; 1669 dirp = ddir->d_inode; 1670 1671 dnew = lookup_one_len(name, ddir, len); 1672 host_err = PTR_ERR(dnew); 1673 if (IS_ERR(dnew)) 1674 goto out_nfserr; 1675 1676 dold = tfhp->fh_dentry; 1677 1678 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt); 1679 if (host_err) { 1680 err = nfserrno(host_err); 1681 goto out_dput; 1682 } 1683 host_err = vfs_link(dold, dirp, dnew); 1684 if (!host_err) { 1685 err = nfserrno(commit_metadata(ffhp)); 1686 if (!err) 1687 err = nfserrno(commit_metadata(tfhp)); 1688 } else { 1689 if (host_err == -EXDEV && rqstp->rq_vers == 2) 1690 err = nfserr_acces; 1691 else 1692 err = nfserrno(host_err); 1693 } 1694 mnt_drop_write(tfhp->fh_export->ex_path.mnt); 1695 out_dput: 1696 dput(dnew); 1697 out_unlock: 1698 fh_unlock(ffhp); 1699 out: 1700 return err; 1701 1702 out_nfserr: 1703 err = nfserrno(host_err); 1704 goto out_unlock; 1705 } 1706 1707 /* 1708 * Rename a file 1709 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1710 */ 1711 __be32 1712 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1713 struct svc_fh *tfhp, char *tname, int tlen) 1714 { 1715 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1716 struct inode *fdir, *tdir; 1717 __be32 err; 1718 int host_err; 1719 1720 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); 1721 if (err) 1722 goto out; 1723 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE); 1724 if (err) 1725 goto out; 1726 1727 fdentry = ffhp->fh_dentry; 1728 fdir = fdentry->d_inode; 1729 1730 tdentry = tfhp->fh_dentry; 1731 tdir = tdentry->d_inode; 1732 1733 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; 1734 if (ffhp->fh_export != tfhp->fh_export) 1735 goto out; 1736 1737 err = nfserr_perm; 1738 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1739 goto out; 1740 1741 /* cannot use fh_lock as we need deadlock protective ordering 1742 * so do it by hand */ 1743 trap = lock_rename(tdentry, fdentry); 1744 ffhp->fh_locked = tfhp->fh_locked = 1; 1745 fill_pre_wcc(ffhp); 1746 fill_pre_wcc(tfhp); 1747 1748 odentry = lookup_one_len(fname, fdentry, flen); 1749 host_err = PTR_ERR(odentry); 1750 if (IS_ERR(odentry)) 1751 goto out_nfserr; 1752 1753 host_err = -ENOENT; 1754 if (!odentry->d_inode) 1755 goto out_dput_old; 1756 host_err = -EINVAL; 1757 if (odentry == trap) 1758 goto out_dput_old; 1759 1760 ndentry = lookup_one_len(tname, tdentry, tlen); 1761 host_err = PTR_ERR(ndentry); 1762 if (IS_ERR(ndentry)) 1763 goto out_dput_old; 1764 host_err = -ENOTEMPTY; 1765 if (ndentry == trap) 1766 goto out_dput_new; 1767 1768 if (svc_msnfs(ffhp) && 1769 ((atomic_read(&odentry->d_count) > 1) 1770 || (atomic_read(&ndentry->d_count) > 1))) { 1771 host_err = -EPERM; 1772 goto out_dput_new; 1773 } 1774 1775 host_err = -EXDEV; 1776 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) 1777 goto out_dput_new; 1778 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt); 1779 if (host_err) 1780 goto out_dput_new; 1781 1782 host_err = vfs_rename(fdir, odentry, tdir, ndentry); 1783 if (!host_err) { 1784 host_err = commit_metadata(tfhp); 1785 if (!host_err) 1786 host_err = commit_metadata(ffhp); 1787 } 1788 1789 mnt_drop_write(ffhp->fh_export->ex_path.mnt); 1790 1791 out_dput_new: 1792 dput(ndentry); 1793 out_dput_old: 1794 dput(odentry); 1795 out_nfserr: 1796 err = nfserrno(host_err); 1797 1798 /* we cannot reply on fh_unlock on the two filehandles, 1799 * as that would do the wrong thing if the two directories 1800 * were the same, so again we do it by hand 1801 */ 1802 fill_post_wcc(ffhp); 1803 fill_post_wcc(tfhp); 1804 unlock_rename(tdentry, fdentry); 1805 ffhp->fh_locked = tfhp->fh_locked = 0; 1806 1807 out: 1808 return err; 1809 } 1810 1811 /* 1812 * Unlink a file or directory 1813 * N.B. After this call fhp needs an fh_put 1814 */ 1815 __be32 1816 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1817 char *fname, int flen) 1818 { 1819 struct dentry *dentry, *rdentry; 1820 struct inode *dirp; 1821 __be32 err; 1822 int host_err; 1823 1824 err = nfserr_acces; 1825 if (!flen || isdotent(fname, flen)) 1826 goto out; 1827 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); 1828 if (err) 1829 goto out; 1830 1831 fh_lock_nested(fhp, I_MUTEX_PARENT); 1832 dentry = fhp->fh_dentry; 1833 dirp = dentry->d_inode; 1834 1835 rdentry = lookup_one_len(fname, dentry, flen); 1836 host_err = PTR_ERR(rdentry); 1837 if (IS_ERR(rdentry)) 1838 goto out_nfserr; 1839 1840 if (!rdentry->d_inode) { 1841 dput(rdentry); 1842 err = nfserr_noent; 1843 goto out; 1844 } 1845 1846 if (!type) 1847 type = rdentry->d_inode->i_mode & S_IFMT; 1848 1849 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1850 if (host_err) 1851 goto out_nfserr; 1852 1853 if (type != S_IFDIR) { /* It's UNLINK */ 1854 #ifdef MSNFS 1855 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1856 (atomic_read(&rdentry->d_count) > 1)) { 1857 host_err = -EPERM; 1858 } else 1859 #endif 1860 host_err = vfs_unlink(dirp, rdentry); 1861 } else { /* It's RMDIR */ 1862 host_err = vfs_rmdir(dirp, rdentry); 1863 } 1864 1865 dput(rdentry); 1866 1867 if (!host_err) 1868 host_err = commit_metadata(fhp); 1869 1870 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1871 out_nfserr: 1872 err = nfserrno(host_err); 1873 out: 1874 return err; 1875 } 1876 1877 /* 1878 * We do this buffering because we must not call back into the file 1879 * system's ->lookup() method from the filldir callback. That may well 1880 * deadlock a number of file systems. 1881 * 1882 * This is based heavily on the implementation of same in XFS. 1883 */ 1884 struct buffered_dirent { 1885 u64 ino; 1886 loff_t offset; 1887 int namlen; 1888 unsigned int d_type; 1889 char name[]; 1890 }; 1891 1892 struct readdir_data { 1893 char *dirent; 1894 size_t used; 1895 int full; 1896 }; 1897 1898 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, 1899 loff_t offset, u64 ino, unsigned int d_type) 1900 { 1901 struct readdir_data *buf = __buf; 1902 struct buffered_dirent *de = (void *)(buf->dirent + buf->used); 1903 unsigned int reclen; 1904 1905 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); 1906 if (buf->used + reclen > PAGE_SIZE) { 1907 buf->full = 1; 1908 return -EINVAL; 1909 } 1910 1911 de->namlen = namlen; 1912 de->offset = offset; 1913 de->ino = ino; 1914 de->d_type = d_type; 1915 memcpy(de->name, name, namlen); 1916 buf->used += reclen; 1917 1918 return 0; 1919 } 1920 1921 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, 1922 struct readdir_cd *cdp, loff_t *offsetp) 1923 { 1924 struct readdir_data buf; 1925 struct buffered_dirent *de; 1926 int host_err; 1927 int size; 1928 loff_t offset; 1929 1930 buf.dirent = (void *)__get_free_page(GFP_KERNEL); 1931 if (!buf.dirent) 1932 return nfserrno(-ENOMEM); 1933 1934 offset = *offsetp; 1935 1936 while (1) { 1937 struct inode *dir_inode = file->f_path.dentry->d_inode; 1938 unsigned int reclen; 1939 1940 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1941 buf.used = 0; 1942 buf.full = 0; 1943 1944 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf); 1945 if (buf.full) 1946 host_err = 0; 1947 1948 if (host_err < 0) 1949 break; 1950 1951 size = buf.used; 1952 1953 if (!size) 1954 break; 1955 1956 /* 1957 * Various filldir functions may end up calling back into 1958 * lookup_one_len() and the file system's ->lookup() method. 1959 * These expect i_mutex to be held, as it would within readdir. 1960 */ 1961 host_err = mutex_lock_killable(&dir_inode->i_mutex); 1962 if (host_err) 1963 break; 1964 1965 de = (struct buffered_dirent *)buf.dirent; 1966 while (size > 0) { 1967 offset = de->offset; 1968 1969 if (func(cdp, de->name, de->namlen, de->offset, 1970 de->ino, de->d_type)) 1971 break; 1972 1973 if (cdp->err != nfs_ok) 1974 break; 1975 1976 reclen = ALIGN(sizeof(*de) + de->namlen, 1977 sizeof(u64)); 1978 size -= reclen; 1979 de = (struct buffered_dirent *)((char *)de + reclen); 1980 } 1981 mutex_unlock(&dir_inode->i_mutex); 1982 if (size > 0) /* We bailed out early */ 1983 break; 1984 1985 offset = vfs_llseek(file, 0, SEEK_CUR); 1986 } 1987 1988 free_page((unsigned long)(buf.dirent)); 1989 1990 if (host_err) 1991 return nfserrno(host_err); 1992 1993 *offsetp = offset; 1994 return cdp->err; 1995 } 1996 1997 /* 1998 * Read entries from a directory. 1999 * The NFSv3/4 verifier we ignore for now. 2000 */ 2001 __be32 2002 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 2003 struct readdir_cd *cdp, filldir_t func) 2004 { 2005 __be32 err; 2006 struct file *file; 2007 loff_t offset = *offsetp; 2008 2009 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file); 2010 if (err) 2011 goto out; 2012 2013 offset = vfs_llseek(file, offset, 0); 2014 if (offset < 0) { 2015 err = nfserrno((int)offset); 2016 goto out_close; 2017 } 2018 2019 err = nfsd_buffered_readdir(file, func, cdp, offsetp); 2020 2021 if (err == nfserr_eof || err == nfserr_toosmall) 2022 err = nfs_ok; /* can still be found in ->err */ 2023 out_close: 2024 nfsd_close(file); 2025 out: 2026 return err; 2027 } 2028 2029 /* 2030 * Get file system stats 2031 * N.B. After this call fhp needs an fh_put 2032 */ 2033 __be32 2034 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) 2035 { 2036 struct path path = { 2037 .mnt = fhp->fh_export->ex_path.mnt, 2038 .dentry = fhp->fh_dentry, 2039 }; 2040 __be32 err; 2041 2042 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); 2043 if (!err && vfs_statfs(&path, stat)) 2044 err = nfserr_io; 2045 return err; 2046 } 2047 2048 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) 2049 { 2050 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; 2051 } 2052 2053 /* 2054 * Check for a user's access permissions to this inode. 2055 */ 2056 __be32 2057 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, 2058 struct dentry *dentry, int acc) 2059 { 2060 struct inode *inode = dentry->d_inode; 2061 int err; 2062 2063 if (acc == NFSD_MAY_NOP) 2064 return 0; 2065 #if 0 2066 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 2067 acc, 2068 (acc & NFSD_MAY_READ)? " read" : "", 2069 (acc & NFSD_MAY_WRITE)? " write" : "", 2070 (acc & NFSD_MAY_EXEC)? " exec" : "", 2071 (acc & NFSD_MAY_SATTR)? " sattr" : "", 2072 (acc & NFSD_MAY_TRUNC)? " trunc" : "", 2073 (acc & NFSD_MAY_LOCK)? " lock" : "", 2074 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", 2075 inode->i_mode, 2076 IS_IMMUTABLE(inode)? " immut" : "", 2077 IS_APPEND(inode)? " append" : "", 2078 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); 2079 dprintk(" owner %d/%d user %d/%d\n", 2080 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); 2081 #endif 2082 2083 /* Normally we reject any write/sattr etc access on a read-only file 2084 * system. But if it is IRIX doing check on write-access for a 2085 * device special file, we ignore rofs. 2086 */ 2087 if (!(acc & NFSD_MAY_LOCAL_ACCESS)) 2088 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { 2089 if (exp_rdonly(rqstp, exp) || 2090 __mnt_is_readonly(exp->ex_path.mnt)) 2091 return nfserr_rofs; 2092 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) 2093 return nfserr_perm; 2094 } 2095 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) 2096 return nfserr_perm; 2097 2098 if (acc & NFSD_MAY_LOCK) { 2099 /* If we cannot rely on authentication in NLM requests, 2100 * just allow locks, otherwise require read permission, or 2101 * ownership 2102 */ 2103 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 2104 return 0; 2105 else 2106 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE; 2107 } 2108 /* 2109 * The file owner always gets access permission for accesses that 2110 * would normally be checked at open time. This is to make 2111 * file access work even when the client has done a fchmod(fd, 0). 2112 * 2113 * However, `cp foo bar' should fail nevertheless when bar is 2114 * readonly. A sensible way to do this might be to reject all 2115 * attempts to truncate a read-only file, because a creat() call 2116 * always implies file truncation. 2117 * ... but this isn't really fair. A process may reasonably call 2118 * ftruncate on an open file descriptor on a file with perm 000. 2119 * We must trust the client to do permission checking - using "ACCESS" 2120 * with NFSv3. 2121 */ 2122 if ((acc & NFSD_MAY_OWNER_OVERRIDE) && 2123 inode->i_uid == current_fsuid()) 2124 return 0; 2125 2126 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ 2127 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); 2128 2129 /* Allow read access to binaries even when mode 111 */ 2130 if (err == -EACCES && S_ISREG(inode->i_mode) && 2131 acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE)) 2132 err = inode_permission(inode, MAY_EXEC); 2133 2134 return err? nfserrno(err) : 0; 2135 } 2136 2137 void 2138 nfsd_racache_shutdown(void) 2139 { 2140 struct raparms *raparm, *last_raparm; 2141 unsigned int i; 2142 2143 dprintk("nfsd: freeing readahead buffers.\n"); 2144 2145 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2146 raparm = raparm_hash[i].pb_head; 2147 while(raparm) { 2148 last_raparm = raparm; 2149 raparm = raparm->p_next; 2150 kfree(last_raparm); 2151 } 2152 raparm_hash[i].pb_head = NULL; 2153 } 2154 } 2155 /* 2156 * Initialize readahead param cache 2157 */ 2158 int 2159 nfsd_racache_init(int cache_size) 2160 { 2161 int i; 2162 int j = 0; 2163 int nperbucket; 2164 struct raparms **raparm = NULL; 2165 2166 2167 if (raparm_hash[0].pb_head) 2168 return 0; 2169 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE); 2170 if (nperbucket < 2) 2171 nperbucket = 2; 2172 cache_size = nperbucket * RAPARM_HASH_SIZE; 2173 2174 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); 2175 2176 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2177 spin_lock_init(&raparm_hash[i].pb_lock); 2178 2179 raparm = &raparm_hash[i].pb_head; 2180 for (j = 0; j < nperbucket; j++) { 2181 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL); 2182 if (!*raparm) 2183 goto out_nomem; 2184 raparm = &(*raparm)->p_next; 2185 } 2186 *raparm = NULL; 2187 } 2188 2189 nfsdstats.ra_size = cache_size; 2190 return 0; 2191 2192 out_nomem: 2193 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n"); 2194 nfsd_racache_shutdown(); 2195 return -ENOMEM; 2196 } 2197 2198 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 2199 struct posix_acl * 2200 nfsd_get_posix_acl(struct svc_fh *fhp, int type) 2201 { 2202 struct inode *inode = fhp->fh_dentry->d_inode; 2203 char *name; 2204 void *value = NULL; 2205 ssize_t size; 2206 struct posix_acl *acl; 2207 2208 if (!IS_POSIXACL(inode)) 2209 return ERR_PTR(-EOPNOTSUPP); 2210 2211 switch (type) { 2212 case ACL_TYPE_ACCESS: 2213 name = POSIX_ACL_XATTR_ACCESS; 2214 break; 2215 case ACL_TYPE_DEFAULT: 2216 name = POSIX_ACL_XATTR_DEFAULT; 2217 break; 2218 default: 2219 return ERR_PTR(-EOPNOTSUPP); 2220 } 2221 2222 size = nfsd_getxattr(fhp->fh_dentry, name, &value); 2223 if (size < 0) 2224 return ERR_PTR(size); 2225 2226 acl = posix_acl_from_xattr(value, size); 2227 kfree(value); 2228 return acl; 2229 } 2230 2231 int 2232 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) 2233 { 2234 struct inode *inode = fhp->fh_dentry->d_inode; 2235 char *name; 2236 void *value = NULL; 2237 size_t size; 2238 int error; 2239 2240 if (!IS_POSIXACL(inode) || 2241 !inode->i_op->setxattr || !inode->i_op->removexattr) 2242 return -EOPNOTSUPP; 2243 switch(type) { 2244 case ACL_TYPE_ACCESS: 2245 name = POSIX_ACL_XATTR_ACCESS; 2246 break; 2247 case ACL_TYPE_DEFAULT: 2248 name = POSIX_ACL_XATTR_DEFAULT; 2249 break; 2250 default: 2251 return -EOPNOTSUPP; 2252 } 2253 2254 if (acl && acl->a_count) { 2255 size = posix_acl_xattr_size(acl->a_count); 2256 value = kmalloc(size, GFP_KERNEL); 2257 if (!value) 2258 return -ENOMEM; 2259 error = posix_acl_to_xattr(acl, value, size); 2260 if (error < 0) 2261 goto getout; 2262 size = error; 2263 } else 2264 size = 0; 2265 2266 error = mnt_want_write(fhp->fh_export->ex_path.mnt); 2267 if (error) 2268 goto getout; 2269 if (size) 2270 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); 2271 else { 2272 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) 2273 error = 0; 2274 else { 2275 error = vfs_removexattr(fhp->fh_dentry, name); 2276 if (error == -ENODATA) 2277 error = 0; 2278 } 2279 } 2280 mnt_drop_write(fhp->fh_export->ex_path.mnt); 2281 2282 getout: 2283 kfree(value); 2284 return error; 2285 } 2286 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 2287