1 /* 2 * File operations used by nfsd. Some of these have been ripped from 3 * other parts of the kernel because they weren't exported, others 4 * are partial duplicates with added or changed functionality. 5 * 6 * Note that several functions dget() the dentry upon which they want 7 * to act, most notably those that create directory entries. Response 8 * dentry's are dput()'d if necessary in the release callback. 9 * So if you notice code paths that apparently fail to dput() the 10 * dentry, don't worry--they have been taken care of. 11 * 12 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de> 13 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp> 14 */ 15 16 #include <linux/fs.h> 17 #include <linux/file.h> 18 #include <linux/splice.h> 19 #include <linux/fcntl.h> 20 #include <linux/namei.h> 21 #include <linux/delay.h> 22 #include <linux/fsnotify.h> 23 #include <linux/posix_acl_xattr.h> 24 #include <linux/xattr.h> 25 #include <linux/jhash.h> 26 #include <linux/ima.h> 27 #include <linux/slab.h> 28 #include <asm/uaccess.h> 29 #include <linux/exportfs.h> 30 #include <linux/writeback.h> 31 32 #ifdef CONFIG_NFSD_V3 33 #include "xdr3.h" 34 #endif /* CONFIG_NFSD_V3 */ 35 36 #ifdef CONFIG_NFSD_V4 37 #include "acl.h" 38 #include "idmap.h" 39 #endif /* CONFIG_NFSD_V4 */ 40 41 #include "nfsd.h" 42 #include "vfs.h" 43 44 #define NFSDDBG_FACILITY NFSDDBG_FILEOP 45 46 47 /* 48 * This is a cache of readahead params that help us choose the proper 49 * readahead strategy. Initially, we set all readahead parameters to 0 50 * and let the VFS handle things. 51 * If you increase the number of cached files very much, you'll need to 52 * add a hash table here. 53 */ 54 struct raparms { 55 struct raparms *p_next; 56 unsigned int p_count; 57 ino_t p_ino; 58 dev_t p_dev; 59 int p_set; 60 struct file_ra_state p_ra; 61 unsigned int p_hindex; 62 }; 63 64 struct raparm_hbucket { 65 struct raparms *pb_head; 66 spinlock_t pb_lock; 67 } ____cacheline_aligned_in_smp; 68 69 #define RAPARM_HASH_BITS 4 70 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS) 71 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1) 72 static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE]; 73 74 /* 75 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 76 * a mount point. 77 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged, 78 * or nfs_ok having possibly changed *dpp and *expp 79 */ 80 int 81 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 82 struct svc_export **expp) 83 { 84 struct svc_export *exp = *expp, *exp2 = NULL; 85 struct dentry *dentry = *dpp; 86 struct path path = {.mnt = mntget(exp->ex_path.mnt), 87 .dentry = dget(dentry)}; 88 int err = 0; 89 90 err = follow_down(&path, false); 91 if (err < 0) 92 goto out; 93 94 exp2 = rqst_exp_get_by_name(rqstp, &path); 95 if (IS_ERR(exp2)) { 96 err = PTR_ERR(exp2); 97 /* 98 * We normally allow NFS clients to continue 99 * "underneath" a mountpoint that is not exported. 100 * The exception is V4ROOT, where no traversal is ever 101 * allowed without an explicit export of the new 102 * directory. 103 */ 104 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT)) 105 err = 0; 106 path_put(&path); 107 goto out; 108 } 109 if (nfsd_v4client(rqstp) || 110 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) { 111 /* successfully crossed mount point */ 112 /* 113 * This is subtle: path.dentry is *not* on path.mnt 114 * at this point. The only reason we are safe is that 115 * original mnt is pinned down by exp, so we should 116 * put path *before* putting exp 117 */ 118 *dpp = path.dentry; 119 path.dentry = dentry; 120 *expp = exp2; 121 exp2 = exp; 122 } 123 path_put(&path); 124 exp_put(exp2); 125 out: 126 return err; 127 } 128 129 static void follow_to_parent(struct path *path) 130 { 131 struct dentry *dp; 132 133 while (path->dentry == path->mnt->mnt_root && follow_up(path)) 134 ; 135 dp = dget_parent(path->dentry); 136 dput(path->dentry); 137 path->dentry = dp; 138 } 139 140 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp) 141 { 142 struct svc_export *exp2; 143 struct path path = {.mnt = mntget((*exp)->ex_path.mnt), 144 .dentry = dget(dparent)}; 145 146 follow_to_parent(&path); 147 148 exp2 = rqst_exp_parent(rqstp, &path); 149 if (PTR_ERR(exp2) == -ENOENT) { 150 *dentryp = dget(dparent); 151 } else if (IS_ERR(exp2)) { 152 path_put(&path); 153 return PTR_ERR(exp2); 154 } else { 155 *dentryp = dget(path.dentry); 156 exp_put(*exp); 157 *exp = exp2; 158 } 159 path_put(&path); 160 return 0; 161 } 162 163 /* 164 * For nfsd purposes, we treat V4ROOT exports as though there was an 165 * export at *every* directory. 166 */ 167 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) 168 { 169 if (d_mountpoint(dentry)) 170 return 1; 171 if (!(exp->ex_flags & NFSEXP_V4ROOT)) 172 return 0; 173 return dentry->d_inode != NULL; 174 } 175 176 __be32 177 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, 178 const char *name, unsigned int len, 179 struct svc_export **exp_ret, struct dentry **dentry_ret) 180 { 181 struct svc_export *exp; 182 struct dentry *dparent; 183 struct dentry *dentry; 184 __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 static int nfsd_break_lease(struct inode *inode) 277 { 278 if (!S_ISREG(inode->i_mode)) 279 return 0; 280 return break_lease(inode, O_WRONLY | O_NONBLOCK); 281 } 282 283 /* 284 * Commit metadata changes to stable storage. 285 */ 286 static int 287 commit_metadata(struct svc_fh *fhp) 288 { 289 struct inode *inode = fhp->fh_dentry->d_inode; 290 const struct export_operations *export_ops = inode->i_sb->s_export_op; 291 292 if (!EX_ISSYNC(fhp->fh_export)) 293 return 0; 294 295 if (export_ops->commit_metadata) 296 return export_ops->commit_metadata(inode); 297 return sync_inode_metadata(inode, 1); 298 } 299 300 /* 301 * Set various file attributes. 302 * N.B. After this call fhp needs an fh_put 303 */ 304 __be32 305 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 306 int check_guard, time_t guardtime) 307 { 308 struct dentry *dentry; 309 struct inode *inode; 310 int accmode = NFSD_MAY_SATTR; 311 int ftype = 0; 312 __be32 err; 313 int host_err; 314 int size_change = 0; 315 316 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 317 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; 318 if (iap->ia_valid & ATTR_SIZE) 319 ftype = S_IFREG; 320 321 /* Get inode */ 322 err = fh_verify(rqstp, fhp, ftype, accmode); 323 if (err) 324 goto out; 325 326 dentry = fhp->fh_dentry; 327 inode = dentry->d_inode; 328 329 /* Ignore any mode updates on symlinks */ 330 if (S_ISLNK(inode->i_mode)) 331 iap->ia_valid &= ~ATTR_MODE; 332 333 if (!iap->ia_valid) 334 goto out; 335 336 /* 337 * NFSv2 does not differentiate between "set-[ac]time-to-now" 338 * which only requires access, and "set-[ac]time-to-X" which 339 * requires ownership. 340 * So if it looks like it might be "set both to the same time which 341 * is close to now", and if inode_change_ok fails, then we 342 * convert to "set to now" instead of "set to explicit time" 343 * 344 * We only call inode_change_ok as the last test as technically 345 * it is not an interface that we should be using. It is only 346 * valid if the filesystem does not define it's own i_op->setattr. 347 */ 348 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 349 #define MAX_TOUCH_TIME_ERROR (30*60) 350 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && 351 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) { 352 /* 353 * Looks probable. 354 * 355 * Now just make sure time is in the right ballpark. 356 * Solaris, at least, doesn't seem to care what the time 357 * request is. We require it be within 30 minutes of now. 358 */ 359 time_t delta = iap->ia_atime.tv_sec - get_seconds(); 360 if (delta < 0) 361 delta = -delta; 362 if (delta < MAX_TOUCH_TIME_ERROR && 363 inode_change_ok(inode, iap) != 0) { 364 /* 365 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME. 366 * This will cause notify_change to set these times 367 * to "now" 368 */ 369 iap->ia_valid &= ~BOTH_TIME_SET; 370 } 371 } 372 373 /* 374 * The size case is special. 375 * It changes the file as well as the attributes. 376 */ 377 if (iap->ia_valid & ATTR_SIZE) { 378 if (iap->ia_size < inode->i_size) { 379 err = nfsd_permission(rqstp, fhp->fh_export, dentry, 380 NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE); 381 if (err) 382 goto out; 383 } 384 385 host_err = get_write_access(inode); 386 if (host_err) 387 goto out_nfserr; 388 389 size_change = 1; 390 host_err = locks_verify_truncate(inode, NULL, iap->ia_size); 391 if (host_err) { 392 put_write_access(inode); 393 goto out_nfserr; 394 } 395 } 396 397 /* sanitize the mode change */ 398 if (iap->ia_valid & ATTR_MODE) { 399 iap->ia_mode &= S_IALLUGO; 400 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); 401 } 402 403 /* Revoke setuid/setgid on chown */ 404 if (!S_ISDIR(inode->i_mode) && 405 (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) || 406 ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) { 407 iap->ia_valid |= ATTR_KILL_PRIV; 408 if (iap->ia_valid & ATTR_MODE) { 409 /* we're setting mode too, just clear the s*id bits */ 410 iap->ia_mode &= ~S_ISUID; 411 if (iap->ia_mode & S_IXGRP) 412 iap->ia_mode &= ~S_ISGID; 413 } else { 414 /* set ATTR_KILL_* bits and let VFS handle it */ 415 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID); 416 } 417 } 418 419 /* Change the attributes. */ 420 421 iap->ia_valid |= ATTR_CTIME; 422 423 err = nfserr_notsync; 424 if (!check_guard || guardtime == inode->i_ctime.tv_sec) { 425 host_err = nfsd_break_lease(inode); 426 if (host_err) 427 goto out_nfserr; 428 fh_lock(fhp); 429 430 host_err = notify_change(dentry, iap); 431 err = nfserrno(host_err); 432 fh_unlock(fhp); 433 } 434 if (size_change) 435 put_write_access(inode); 436 if (!err) 437 commit_metadata(fhp); 438 out: 439 return err; 440 441 out_nfserr: 442 err = nfserrno(host_err); 443 goto out; 444 } 445 446 #if defined(CONFIG_NFSD_V2_ACL) || \ 447 defined(CONFIG_NFSD_V3_ACL) || \ 448 defined(CONFIG_NFSD_V4) 449 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf) 450 { 451 ssize_t buflen; 452 ssize_t ret; 453 454 buflen = vfs_getxattr(dentry, key, NULL, 0); 455 if (buflen <= 0) 456 return buflen; 457 458 *buf = kmalloc(buflen, GFP_KERNEL); 459 if (!*buf) 460 return -ENOMEM; 461 462 ret = vfs_getxattr(dentry, key, *buf, buflen); 463 if (ret < 0) 464 kfree(*buf); 465 return ret; 466 } 467 #endif 468 469 #if defined(CONFIG_NFSD_V4) 470 static int 471 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key) 472 { 473 int len; 474 size_t buflen; 475 char *buf = NULL; 476 int error = 0; 477 478 buflen = posix_acl_xattr_size(pacl->a_count); 479 buf = kmalloc(buflen, GFP_KERNEL); 480 error = -ENOMEM; 481 if (buf == NULL) 482 goto out; 483 484 len = posix_acl_to_xattr(pacl, buf, buflen); 485 if (len < 0) { 486 error = len; 487 goto out; 488 } 489 490 error = vfs_setxattr(dentry, key, buf, len, 0); 491 out: 492 kfree(buf); 493 return error; 494 } 495 496 __be32 497 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 498 struct nfs4_acl *acl) 499 { 500 __be32 error; 501 int host_error; 502 struct dentry *dentry; 503 struct inode *inode; 504 struct posix_acl *pacl = NULL, *dpacl = NULL; 505 unsigned int flags = 0; 506 507 /* Get inode */ 508 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); 509 if (error) 510 return error; 511 512 dentry = fhp->fh_dentry; 513 inode = dentry->d_inode; 514 if (S_ISDIR(inode->i_mode)) 515 flags = NFS4_ACL_DIR; 516 517 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 518 if (host_error == -EINVAL) { 519 return nfserr_attrnotsupp; 520 } else if (host_error < 0) 521 goto out_nfserr; 522 523 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); 524 if (host_error < 0) 525 goto out_release; 526 527 if (S_ISDIR(inode->i_mode)) 528 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); 529 530 out_release: 531 posix_acl_release(pacl); 532 posix_acl_release(dpacl); 533 out_nfserr: 534 if (host_error == -EOPNOTSUPP) 535 return nfserr_attrnotsupp; 536 else 537 return nfserrno(host_error); 538 } 539 540 static struct posix_acl * 541 _get_posix_acl(struct dentry *dentry, char *key) 542 { 543 void *buf = NULL; 544 struct posix_acl *pacl = NULL; 545 int buflen; 546 547 buflen = nfsd_getxattr(dentry, key, &buf); 548 if (!buflen) 549 buflen = -ENODATA; 550 if (buflen <= 0) 551 return ERR_PTR(buflen); 552 553 pacl = posix_acl_from_xattr(buf, buflen); 554 kfree(buf); 555 return pacl; 556 } 557 558 int 559 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl) 560 { 561 struct inode *inode = dentry->d_inode; 562 int error = 0; 563 struct posix_acl *pacl = NULL, *dpacl = NULL; 564 unsigned int flags = 0; 565 566 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS); 567 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA) 568 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 569 if (IS_ERR(pacl)) { 570 error = PTR_ERR(pacl); 571 pacl = NULL; 572 goto out; 573 } 574 575 if (S_ISDIR(inode->i_mode)) { 576 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT); 577 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA) 578 dpacl = NULL; 579 else if (IS_ERR(dpacl)) { 580 error = PTR_ERR(dpacl); 581 dpacl = NULL; 582 goto out; 583 } 584 flags = NFS4_ACL_DIR; 585 } 586 587 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags); 588 if (IS_ERR(*acl)) { 589 error = PTR_ERR(*acl); 590 *acl = NULL; 591 } 592 out: 593 posix_acl_release(pacl); 594 posix_acl_release(dpacl); 595 return error; 596 } 597 598 #endif /* defined(CONFIG_NFSD_V4) */ 599 600 #ifdef CONFIG_NFSD_V3 601 /* 602 * Check server access rights to a file system object 603 */ 604 struct accessmap { 605 u32 access; 606 int how; 607 }; 608 static struct accessmap nfs3_regaccess[] = { 609 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 610 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 611 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, 612 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, 613 614 { 0, 0 } 615 }; 616 617 static struct accessmap nfs3_diraccess[] = { 618 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 619 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, 620 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, 621 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, 622 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, 623 624 { 0, 0 } 625 }; 626 627 static struct accessmap nfs3_anyaccess[] = { 628 /* Some clients - Solaris 2.6 at least, make an access call 629 * to the server to check for access for things like /dev/null 630 * (which really, the server doesn't care about). So 631 * We provide simple access checking for them, looking 632 * mainly at mode bits, and we make sure to ignore read-only 633 * filesystem checks 634 */ 635 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 636 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 637 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 638 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 639 640 { 0, 0 } 641 }; 642 643 __be32 644 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 645 { 646 struct accessmap *map; 647 struct svc_export *export; 648 struct dentry *dentry; 649 u32 query, result = 0, sresult = 0; 650 __be32 error; 651 652 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP); 653 if (error) 654 goto out; 655 656 export = fhp->fh_export; 657 dentry = fhp->fh_dentry; 658 659 if (S_ISREG(dentry->d_inode->i_mode)) 660 map = nfs3_regaccess; 661 else if (S_ISDIR(dentry->d_inode->i_mode)) 662 map = nfs3_diraccess; 663 else 664 map = nfs3_anyaccess; 665 666 667 query = *access; 668 for (; map->access; map++) { 669 if (map->access & query) { 670 __be32 err2; 671 672 sresult |= map->access; 673 674 err2 = nfsd_permission(rqstp, export, dentry, map->how); 675 switch (err2) { 676 case nfs_ok: 677 result |= map->access; 678 break; 679 680 /* the following error codes just mean the access was not allowed, 681 * rather than an error occurred */ 682 case nfserr_rofs: 683 case nfserr_acces: 684 case nfserr_perm: 685 /* simply don't "or" in the access bit. */ 686 break; 687 default: 688 error = err2; 689 goto out; 690 } 691 } 692 } 693 *access = result; 694 if (supported) 695 *supported = sresult; 696 697 out: 698 return error; 699 } 700 #endif /* CONFIG_NFSD_V3 */ 701 702 703 704 /* 705 * Open an existing file or directory. 706 * The access argument indicates the type of open (read/write/lock) 707 * N.B. After this call fhp needs an fh_put 708 */ 709 __be32 710 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 711 int access, struct file **filp) 712 { 713 struct dentry *dentry; 714 struct inode *inode; 715 int flags = O_RDONLY|O_LARGEFILE; 716 __be32 err; 717 int host_err = 0; 718 719 validate_process_creds(); 720 721 /* 722 * If we get here, then the client has already done an "open", 723 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 724 * in case a chmod has now revoked permission. 725 */ 726 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE); 727 if (err) 728 goto out; 729 730 dentry = fhp->fh_dentry; 731 inode = dentry->d_inode; 732 733 /* Disallow write access to files with the append-only bit set 734 * or any access when mandatory locking enabled 735 */ 736 err = nfserr_perm; 737 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE)) 738 goto out; 739 /* 740 * We must ignore files (but only files) which might have mandatory 741 * locks on them because there is no way to know if the accesser has 742 * the lock. 743 */ 744 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode)) 745 goto out; 746 747 if (!inode->i_fop) 748 goto out; 749 750 /* 751 * Check to see if there are any leases on this file. 752 * This may block while leases are broken. 753 */ 754 if (!(access & NFSD_MAY_NOT_BREAK_LEASE)) 755 host_err = break_lease(inode, O_NONBLOCK | ((access & NFSD_MAY_WRITE) ? O_WRONLY : 0)); 756 if (host_err) /* NOMEM or WOULDBLOCK */ 757 goto out_nfserr; 758 759 if (access & NFSD_MAY_WRITE) { 760 if (access & NFSD_MAY_READ) 761 flags = O_RDWR|O_LARGEFILE; 762 else 763 flags = O_WRONLY|O_LARGEFILE; 764 } 765 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt), 766 flags, current_cred()); 767 if (IS_ERR(*filp)) 768 host_err = PTR_ERR(*filp); 769 else 770 host_err = ima_file_check(*filp, access); 771 out_nfserr: 772 err = nfserrno(host_err); 773 out: 774 validate_process_creds(); 775 return err; 776 } 777 778 /* 779 * Close a file. 780 */ 781 void 782 nfsd_close(struct file *filp) 783 { 784 fput(filp); 785 } 786 787 /* 788 * Obtain the readahead parameters for the file 789 * specified by (dev, ino). 790 */ 791 792 static inline struct raparms * 793 nfsd_get_raparms(dev_t dev, ino_t ino) 794 { 795 struct raparms *ra, **rap, **frap = NULL; 796 int depth = 0; 797 unsigned int hash; 798 struct raparm_hbucket *rab; 799 800 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK; 801 rab = &raparm_hash[hash]; 802 803 spin_lock(&rab->pb_lock); 804 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) { 805 if (ra->p_ino == ino && ra->p_dev == dev) 806 goto found; 807 depth++; 808 if (ra->p_count == 0) 809 frap = rap; 810 } 811 depth = nfsdstats.ra_size*11/10; 812 if (!frap) { 813 spin_unlock(&rab->pb_lock); 814 return NULL; 815 } 816 rap = frap; 817 ra = *frap; 818 ra->p_dev = dev; 819 ra->p_ino = ino; 820 ra->p_set = 0; 821 ra->p_hindex = hash; 822 found: 823 if (rap != &rab->pb_head) { 824 *rap = ra->p_next; 825 ra->p_next = rab->pb_head; 826 rab->pb_head = ra; 827 } 828 ra->p_count++; 829 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 830 spin_unlock(&rab->pb_lock); 831 return ra; 832 } 833 834 /* 835 * Grab and keep cached pages associated with a file in the svc_rqst 836 * so that they can be passed to the network sendmsg/sendpage routines 837 * directly. They will be released after the sending has completed. 838 */ 839 static int 840 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 841 struct splice_desc *sd) 842 { 843 struct svc_rqst *rqstp = sd->u.data; 844 struct page **pp = rqstp->rq_respages + rqstp->rq_resused; 845 struct page *page = buf->page; 846 size_t size; 847 848 size = sd->len; 849 850 if (rqstp->rq_res.page_len == 0) { 851 get_page(page); 852 put_page(*pp); 853 *pp = page; 854 rqstp->rq_resused++; 855 rqstp->rq_res.page_base = buf->offset; 856 rqstp->rq_res.page_len = size; 857 } else if (page != pp[-1]) { 858 get_page(page); 859 if (*pp) 860 put_page(*pp); 861 *pp = page; 862 rqstp->rq_resused++; 863 rqstp->rq_res.page_len += size; 864 } else 865 rqstp->rq_res.page_len += size; 866 867 return size; 868 } 869 870 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, 871 struct splice_desc *sd) 872 { 873 return __splice_from_pipe(pipe, sd, nfsd_splice_actor); 874 } 875 876 static __be32 877 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 878 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 879 { 880 struct inode *inode; 881 mm_segment_t oldfs; 882 __be32 err; 883 int host_err; 884 885 err = nfserr_perm; 886 inode = file->f_path.dentry->d_inode; 887 888 if (file->f_op->splice_read && rqstp->rq_splice_ok) { 889 struct splice_desc sd = { 890 .len = 0, 891 .total_len = *count, 892 .pos = offset, 893 .u.data = rqstp, 894 }; 895 896 rqstp->rq_resused = 1; 897 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); 898 } else { 899 oldfs = get_fs(); 900 set_fs(KERNEL_DS); 901 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 902 set_fs(oldfs); 903 } 904 905 if (host_err >= 0) { 906 nfsdstats.io_read += host_err; 907 *count = host_err; 908 err = 0; 909 fsnotify_access(file); 910 } else 911 err = nfserrno(host_err); 912 return err; 913 } 914 915 static void kill_suid(struct dentry *dentry) 916 { 917 struct iattr ia; 918 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; 919 920 mutex_lock(&dentry->d_inode->i_mutex); 921 notify_change(dentry, &ia); 922 mutex_unlock(&dentry->d_inode->i_mutex); 923 } 924 925 /* 926 * Gathered writes: If another process is currently writing to the file, 927 * there's a high chance this is another nfsd (triggered by a bulk write 928 * from a client's biod). Rather than syncing the file with each write 929 * request, we sleep for 10 msec. 930 * 931 * I don't know if this roughly approximates C. Juszak's idea of 932 * gathered writes, but it's a nice and simple solution (IMHO), and it 933 * seems to work:-) 934 * 935 * Note: we do this only in the NFSv2 case, since v3 and higher have a 936 * better tool (separate unstable writes and commits) for solving this 937 * problem. 938 */ 939 static int wait_for_concurrent_writes(struct file *file) 940 { 941 struct inode *inode = file->f_path.dentry->d_inode; 942 static ino_t last_ino; 943 static dev_t last_dev; 944 int err = 0; 945 946 if (atomic_read(&inode->i_writecount) > 1 947 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 948 dprintk("nfsd: write defer %d\n", task_pid_nr(current)); 949 msleep(10); 950 dprintk("nfsd: write resume %d\n", task_pid_nr(current)); 951 } 952 953 if (inode->i_state & I_DIRTY) { 954 dprintk("nfsd: write sync %d\n", task_pid_nr(current)); 955 err = vfs_fsync(file, 0); 956 } 957 last_ino = inode->i_ino; 958 last_dev = inode->i_sb->s_dev; 959 return err; 960 } 961 962 static __be32 963 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 964 loff_t offset, struct kvec *vec, int vlen, 965 unsigned long *cnt, int *stablep) 966 { 967 struct svc_export *exp; 968 struct dentry *dentry; 969 struct inode *inode; 970 mm_segment_t oldfs; 971 __be32 err = 0; 972 int host_err; 973 int stable = *stablep; 974 int use_wgather; 975 976 dentry = file->f_path.dentry; 977 inode = dentry->d_inode; 978 exp = fhp->fh_export; 979 980 /* 981 * Request sync writes if 982 * - the sync export option has been set, or 983 * - the client requested O_SYNC behavior (NFSv3 feature). 984 * - The file system doesn't support fsync(). 985 * When NFSv2 gathered writes have been configured for this volume, 986 * flushing the data to disk is handled separately below. 987 */ 988 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); 989 990 if (!file->f_op->fsync) {/* COMMIT3 cannot work */ 991 stable = 2; 992 *stablep = 2; /* FILE_SYNC */ 993 } 994 995 if (!EX_ISSYNC(exp)) 996 stable = 0; 997 if (stable && !use_wgather) { 998 spin_lock(&file->f_lock); 999 file->f_flags |= O_SYNC; 1000 spin_unlock(&file->f_lock); 1001 } 1002 1003 /* Write the data. */ 1004 oldfs = get_fs(); set_fs(KERNEL_DS); 1005 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); 1006 set_fs(oldfs); 1007 if (host_err < 0) 1008 goto out_nfserr; 1009 *cnt = host_err; 1010 nfsdstats.io_write += host_err; 1011 fsnotify_modify(file); 1012 1013 /* clear setuid/setgid flag after write */ 1014 if (inode->i_mode & (S_ISUID | S_ISGID)) 1015 kill_suid(dentry); 1016 1017 if (stable && use_wgather) 1018 host_err = wait_for_concurrent_writes(file); 1019 1020 out_nfserr: 1021 dprintk("nfsd: write complete host_err=%d\n", host_err); 1022 if (host_err >= 0) 1023 err = 0; 1024 else 1025 err = nfserrno(host_err); 1026 return err; 1027 } 1028 1029 /* 1030 * Read data from a file. count must contain the requested read count 1031 * on entry. On return, *count contains the number of bytes actually read. 1032 * N.B. After this call fhp needs an fh_put 1033 */ 1034 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 1035 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 1036 { 1037 struct file *file; 1038 struct inode *inode; 1039 struct raparms *ra; 1040 __be32 err; 1041 1042 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); 1043 if (err) 1044 return err; 1045 1046 inode = file->f_path.dentry->d_inode; 1047 1048 /* Get readahead parameters */ 1049 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 1050 1051 if (ra && ra->p_set) 1052 file->f_ra = ra->p_ra; 1053 1054 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1055 1056 /* Write back readahead params */ 1057 if (ra) { 1058 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex]; 1059 spin_lock(&rab->pb_lock); 1060 ra->p_ra = file->f_ra; 1061 ra->p_set = 1; 1062 ra->p_count--; 1063 spin_unlock(&rab->pb_lock); 1064 } 1065 1066 nfsd_close(file); 1067 return err; 1068 } 1069 1070 /* As above, but use the provided file descriptor. */ 1071 __be32 1072 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1073 loff_t offset, struct kvec *vec, int vlen, 1074 unsigned long *count) 1075 { 1076 __be32 err; 1077 1078 if (file) { 1079 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1080 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE); 1081 if (err) 1082 goto out; 1083 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1084 } else /* Note file may still be NULL in NFSv4 special stateid case: */ 1085 err = nfsd_read(rqstp, fhp, offset, vec, vlen, count); 1086 out: 1087 return err; 1088 } 1089 1090 /* 1091 * Write data to a file. 1092 * The stable flag requests synchronous writes. 1093 * N.B. After this call fhp needs an fh_put 1094 */ 1095 __be32 1096 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1097 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, 1098 int *stablep) 1099 { 1100 __be32 err = 0; 1101 1102 if (file) { 1103 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1104 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE); 1105 if (err) 1106 goto out; 1107 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1108 stablep); 1109 } else { 1110 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); 1111 if (err) 1112 goto out; 1113 1114 if (cnt) 1115 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1116 cnt, stablep); 1117 nfsd_close(file); 1118 } 1119 out: 1120 return err; 1121 } 1122 1123 #ifdef CONFIG_NFSD_V3 1124 /* 1125 * Commit all pending writes to stable storage. 1126 * 1127 * Note: we only guarantee that data that lies within the range specified 1128 * by the 'offset' and 'count' parameters will be synced. 1129 * 1130 * Unfortunately we cannot lock the file to make sure we return full WCC 1131 * data to the client, as locking happens lower down in the filesystem. 1132 */ 1133 __be32 1134 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1135 loff_t offset, unsigned long count) 1136 { 1137 struct file *file; 1138 loff_t end = LLONG_MAX; 1139 __be32 err = nfserr_inval; 1140 1141 if (offset < 0) 1142 goto out; 1143 if (count != 0) { 1144 end = offset + (loff_t)count - 1; 1145 if (end < offset) 1146 goto out; 1147 } 1148 1149 err = nfsd_open(rqstp, fhp, S_IFREG, 1150 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file); 1151 if (err) 1152 goto out; 1153 if (EX_ISSYNC(fhp->fh_export)) { 1154 int err2 = vfs_fsync_range(file, offset, end, 0); 1155 1156 if (err2 != -EINVAL) 1157 err = nfserrno(err2); 1158 else 1159 err = nfserr_notsupp; 1160 } 1161 1162 nfsd_close(file); 1163 out: 1164 return err; 1165 } 1166 #endif /* CONFIG_NFSD_V3 */ 1167 1168 static __be32 1169 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp, 1170 struct iattr *iap) 1171 { 1172 /* 1173 * Mode has already been set earlier in create: 1174 */ 1175 iap->ia_valid &= ~ATTR_MODE; 1176 /* 1177 * Setting uid/gid works only for root. Irix appears to 1178 * send along the gid on create when it tries to implement 1179 * setgid directories via NFS: 1180 */ 1181 if (current_fsuid() != 0) 1182 iap->ia_valid &= ~(ATTR_UID|ATTR_GID); 1183 if (iap->ia_valid) 1184 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1185 return 0; 1186 } 1187 1188 /* HPUX client sometimes creates a file in mode 000, and sets size to 0. 1189 * setting size to 0 may fail for some specific file systems by the permission 1190 * checking which requires WRITE permission but the mode is 000. 1191 * we ignore the resizing(to 0) on the just new created file, since the size is 1192 * 0 after file created. 1193 * 1194 * call this only after vfs_create() is called. 1195 * */ 1196 static void 1197 nfsd_check_ignore_resizing(struct iattr *iap) 1198 { 1199 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) 1200 iap->ia_valid &= ~ATTR_SIZE; 1201 } 1202 1203 /* 1204 * Create a file (regular, directory, device, fifo); UNIX sockets 1205 * not yet implemented. 1206 * If the response fh has been verified, the parent directory should 1207 * already be locked. Note that the parent directory is left locked. 1208 * 1209 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1210 */ 1211 __be32 1212 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1213 char *fname, int flen, struct iattr *iap, 1214 int type, dev_t rdev, struct svc_fh *resfhp) 1215 { 1216 struct dentry *dentry, *dchild = NULL; 1217 struct inode *dirp; 1218 __be32 err; 1219 __be32 err2; 1220 int host_err; 1221 1222 err = nfserr_perm; 1223 if (!flen) 1224 goto out; 1225 err = nfserr_exist; 1226 if (isdotent(fname, flen)) 1227 goto out; 1228 1229 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1230 if (err) 1231 goto out; 1232 1233 dentry = fhp->fh_dentry; 1234 dirp = dentry->d_inode; 1235 1236 err = nfserr_notdir; 1237 if (!dirp->i_op->lookup) 1238 goto out; 1239 /* 1240 * Check whether the response file handle has been verified yet. 1241 * If it has, the parent directory should already be locked. 1242 */ 1243 if (!resfhp->fh_dentry) { 1244 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1245 fh_lock_nested(fhp, I_MUTEX_PARENT); 1246 dchild = lookup_one_len(fname, dentry, flen); 1247 host_err = PTR_ERR(dchild); 1248 if (IS_ERR(dchild)) 1249 goto out_nfserr; 1250 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1251 if (err) 1252 goto out; 1253 } else { 1254 /* called from nfsd_proc_create */ 1255 dchild = dget(resfhp->fh_dentry); 1256 if (!fhp->fh_locked) { 1257 /* not actually possible */ 1258 printk(KERN_ERR 1259 "nfsd_create: parent %s/%s not locked!\n", 1260 dentry->d_parent->d_name.name, 1261 dentry->d_name.name); 1262 err = nfserr_io; 1263 goto out; 1264 } 1265 } 1266 /* 1267 * Make sure the child dentry is still negative ... 1268 */ 1269 err = nfserr_exist; 1270 if (dchild->d_inode) { 1271 dprintk("nfsd_create: dentry %s/%s not negative!\n", 1272 dentry->d_name.name, dchild->d_name.name); 1273 goto out; 1274 } 1275 1276 if (!(iap->ia_valid & ATTR_MODE)) 1277 iap->ia_mode = 0; 1278 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1279 1280 err = nfserr_inval; 1281 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) { 1282 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", 1283 type); 1284 goto out; 1285 } 1286 1287 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1288 if (host_err) 1289 goto out_nfserr; 1290 1291 /* 1292 * Get the dir op function pointer. 1293 */ 1294 err = 0; 1295 switch (type) { 1296 case S_IFREG: 1297 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1298 if (!host_err) 1299 nfsd_check_ignore_resizing(iap); 1300 break; 1301 case S_IFDIR: 1302 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1303 break; 1304 case S_IFCHR: 1305 case S_IFBLK: 1306 case S_IFIFO: 1307 case S_IFSOCK: 1308 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1309 break; 1310 } 1311 if (host_err < 0) { 1312 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1313 goto out_nfserr; 1314 } 1315 1316 err = nfsd_create_setattr(rqstp, resfhp, iap); 1317 1318 /* 1319 * nfsd_setattr already committed the child. Transactional filesystems 1320 * had a chance to commit changes for both parent and child 1321 * simultaneously making the following commit_metadata a noop. 1322 */ 1323 err2 = nfserrno(commit_metadata(fhp)); 1324 if (err2) 1325 err = err2; 1326 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1327 /* 1328 * Update the file handle to get the new inode info. 1329 */ 1330 if (!err) 1331 err = fh_update(resfhp); 1332 out: 1333 if (dchild && !IS_ERR(dchild)) 1334 dput(dchild); 1335 return err; 1336 1337 out_nfserr: 1338 err = nfserrno(host_err); 1339 goto out; 1340 } 1341 1342 #ifdef CONFIG_NFSD_V3 1343 /* 1344 * NFSv3 version of nfsd_create 1345 */ 1346 __be32 1347 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, 1348 char *fname, int flen, struct iattr *iap, 1349 struct svc_fh *resfhp, int createmode, u32 *verifier, 1350 int *truncp, int *created) 1351 { 1352 struct dentry *dentry, *dchild = NULL; 1353 struct inode *dirp; 1354 __be32 err; 1355 int host_err; 1356 __u32 v_mtime=0, v_atime=0; 1357 1358 err = nfserr_perm; 1359 if (!flen) 1360 goto out; 1361 err = nfserr_exist; 1362 if (isdotent(fname, flen)) 1363 goto out; 1364 if (!(iap->ia_valid & ATTR_MODE)) 1365 iap->ia_mode = 0; 1366 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1367 if (err) 1368 goto out; 1369 1370 dentry = fhp->fh_dentry; 1371 dirp = dentry->d_inode; 1372 1373 /* Get all the sanity checks out of the way before 1374 * we lock the parent. */ 1375 err = nfserr_notdir; 1376 if (!dirp->i_op->lookup) 1377 goto out; 1378 fh_lock_nested(fhp, I_MUTEX_PARENT); 1379 1380 /* 1381 * Compose the response file handle. 1382 */ 1383 dchild = lookup_one_len(fname, dentry, flen); 1384 host_err = PTR_ERR(dchild); 1385 if (IS_ERR(dchild)) 1386 goto out_nfserr; 1387 1388 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1389 if (err) 1390 goto out; 1391 1392 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1393 /* solaris7 gets confused (bugid 4218508) if these have 1394 * the high bit set, so just clear the high bits. If this is 1395 * ever changed to use different attrs for storing the 1396 * verifier, then do_open_lookup() will also need to be fixed 1397 * accordingly. 1398 */ 1399 v_mtime = verifier[0]&0x7fffffff; 1400 v_atime = verifier[1]&0x7fffffff; 1401 } 1402 1403 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1404 if (host_err) 1405 goto out_nfserr; 1406 if (dchild->d_inode) { 1407 err = 0; 1408 1409 switch (createmode) { 1410 case NFS3_CREATE_UNCHECKED: 1411 if (! S_ISREG(dchild->d_inode->i_mode)) 1412 err = nfserr_exist; 1413 else if (truncp) { 1414 /* in nfsv4, we need to treat this case a little 1415 * differently. we don't want to truncate the 1416 * file now; this would be wrong if the OPEN 1417 * fails for some other reason. furthermore, 1418 * if the size is nonzero, we should ignore it 1419 * according to spec! 1420 */ 1421 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1422 } 1423 else { 1424 iap->ia_valid &= ATTR_SIZE; 1425 goto set_attr; 1426 } 1427 break; 1428 case NFS3_CREATE_EXCLUSIVE: 1429 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1430 && dchild->d_inode->i_atime.tv_sec == v_atime 1431 && dchild->d_inode->i_size == 0 ) 1432 break; 1433 /* fallthru */ 1434 case NFS3_CREATE_GUARDED: 1435 err = nfserr_exist; 1436 } 1437 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1438 goto out; 1439 } 1440 1441 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1442 if (host_err < 0) { 1443 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1444 goto out_nfserr; 1445 } 1446 if (created) 1447 *created = 1; 1448 1449 nfsd_check_ignore_resizing(iap); 1450 1451 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1452 /* Cram the verifier into atime/mtime */ 1453 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1454 | ATTR_MTIME_SET|ATTR_ATIME_SET; 1455 /* XXX someone who knows this better please fix it for nsec */ 1456 iap->ia_mtime.tv_sec = v_mtime; 1457 iap->ia_atime.tv_sec = v_atime; 1458 iap->ia_mtime.tv_nsec = 0; 1459 iap->ia_atime.tv_nsec = 0; 1460 } 1461 1462 set_attr: 1463 err = nfsd_create_setattr(rqstp, resfhp, iap); 1464 1465 /* 1466 * nfsd_setattr already committed the child (and possibly also the parent). 1467 */ 1468 if (!err) 1469 err = nfserrno(commit_metadata(fhp)); 1470 1471 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1472 /* 1473 * Update the filehandle to get the new inode info. 1474 */ 1475 if (!err) 1476 err = fh_update(resfhp); 1477 1478 out: 1479 fh_unlock(fhp); 1480 if (dchild && !IS_ERR(dchild)) 1481 dput(dchild); 1482 return err; 1483 1484 out_nfserr: 1485 err = nfserrno(host_err); 1486 goto out; 1487 } 1488 #endif /* CONFIG_NFSD_V3 */ 1489 1490 /* 1491 * Read a symlink. On entry, *lenp must contain the maximum path length that 1492 * fits into the buffer. On return, it contains the true length. 1493 * N.B. After this call fhp needs an fh_put 1494 */ 1495 __be32 1496 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1497 { 1498 struct dentry *dentry; 1499 struct inode *inode; 1500 mm_segment_t oldfs; 1501 __be32 err; 1502 int host_err; 1503 1504 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); 1505 if (err) 1506 goto out; 1507 1508 dentry = fhp->fh_dentry; 1509 inode = dentry->d_inode; 1510 1511 err = nfserr_inval; 1512 if (!inode->i_op->readlink) 1513 goto out; 1514 1515 touch_atime(fhp->fh_export->ex_path.mnt, dentry); 1516 /* N.B. Why does this call need a get_fs()?? 1517 * Remove the set_fs and watch the fireworks:-) --okir 1518 */ 1519 1520 oldfs = get_fs(); set_fs(KERNEL_DS); 1521 host_err = inode->i_op->readlink(dentry, buf, *lenp); 1522 set_fs(oldfs); 1523 1524 if (host_err < 0) 1525 goto out_nfserr; 1526 *lenp = host_err; 1527 err = 0; 1528 out: 1529 return err; 1530 1531 out_nfserr: 1532 err = nfserrno(host_err); 1533 goto out; 1534 } 1535 1536 /* 1537 * Create a symlink and look up its inode 1538 * N.B. After this call _both_ fhp and resfhp need an fh_put 1539 */ 1540 __be32 1541 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1542 char *fname, int flen, 1543 char *path, int plen, 1544 struct svc_fh *resfhp, 1545 struct iattr *iap) 1546 { 1547 struct dentry *dentry, *dnew; 1548 __be32 err, cerr; 1549 int host_err; 1550 1551 err = nfserr_noent; 1552 if (!flen || !plen) 1553 goto out; 1554 err = nfserr_exist; 1555 if (isdotent(fname, flen)) 1556 goto out; 1557 1558 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1559 if (err) 1560 goto out; 1561 fh_lock(fhp); 1562 dentry = fhp->fh_dentry; 1563 dnew = lookup_one_len(fname, dentry, flen); 1564 host_err = PTR_ERR(dnew); 1565 if (IS_ERR(dnew)) 1566 goto out_nfserr; 1567 1568 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1569 if (host_err) 1570 goto out_nfserr; 1571 1572 if (unlikely(path[plen] != 0)) { 1573 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1574 if (path_alloced == NULL) 1575 host_err = -ENOMEM; 1576 else { 1577 strncpy(path_alloced, path, plen); 1578 path_alloced[plen] = 0; 1579 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced); 1580 kfree(path_alloced); 1581 } 1582 } else 1583 host_err = vfs_symlink(dentry->d_inode, dnew, path); 1584 err = nfserrno(host_err); 1585 if (!err) 1586 err = nfserrno(commit_metadata(fhp)); 1587 fh_unlock(fhp); 1588 1589 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1590 1591 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1592 dput(dnew); 1593 if (err==0) err = cerr; 1594 out: 1595 return err; 1596 1597 out_nfserr: 1598 err = nfserrno(host_err); 1599 goto out; 1600 } 1601 1602 /* 1603 * Create a hardlink 1604 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1605 */ 1606 __be32 1607 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1608 char *name, int len, struct svc_fh *tfhp) 1609 { 1610 struct dentry *ddir, *dnew, *dold; 1611 struct inode *dirp; 1612 __be32 err; 1613 int host_err; 1614 1615 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); 1616 if (err) 1617 goto out; 1618 err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP); 1619 if (err) 1620 goto out; 1621 1622 err = nfserr_perm; 1623 if (!len) 1624 goto out; 1625 err = nfserr_exist; 1626 if (isdotent(name, len)) 1627 goto out; 1628 1629 fh_lock_nested(ffhp, I_MUTEX_PARENT); 1630 ddir = ffhp->fh_dentry; 1631 dirp = ddir->d_inode; 1632 1633 dnew = lookup_one_len(name, ddir, len); 1634 host_err = PTR_ERR(dnew); 1635 if (IS_ERR(dnew)) 1636 goto out_nfserr; 1637 1638 dold = tfhp->fh_dentry; 1639 1640 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt); 1641 if (host_err) { 1642 err = nfserrno(host_err); 1643 goto out_dput; 1644 } 1645 err = nfserr_noent; 1646 if (!dold->d_inode) 1647 goto out_drop_write; 1648 host_err = nfsd_break_lease(dold->d_inode); 1649 if (host_err) 1650 goto out_drop_write; 1651 host_err = vfs_link(dold, dirp, dnew); 1652 if (!host_err) { 1653 err = nfserrno(commit_metadata(ffhp)); 1654 if (!err) 1655 err = nfserrno(commit_metadata(tfhp)); 1656 } else { 1657 if (host_err == -EXDEV && rqstp->rq_vers == 2) 1658 err = nfserr_acces; 1659 else 1660 err = nfserrno(host_err); 1661 } 1662 out_drop_write: 1663 mnt_drop_write(tfhp->fh_export->ex_path.mnt); 1664 out_dput: 1665 dput(dnew); 1666 out_unlock: 1667 fh_unlock(ffhp); 1668 out: 1669 return err; 1670 1671 out_nfserr: 1672 err = nfserrno(host_err); 1673 goto out_unlock; 1674 } 1675 1676 /* 1677 * Rename a file 1678 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1679 */ 1680 __be32 1681 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1682 struct svc_fh *tfhp, char *tname, int tlen) 1683 { 1684 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1685 struct inode *fdir, *tdir; 1686 __be32 err; 1687 int host_err; 1688 1689 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); 1690 if (err) 1691 goto out; 1692 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE); 1693 if (err) 1694 goto out; 1695 1696 fdentry = ffhp->fh_dentry; 1697 fdir = fdentry->d_inode; 1698 1699 tdentry = tfhp->fh_dentry; 1700 tdir = tdentry->d_inode; 1701 1702 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; 1703 if (ffhp->fh_export != tfhp->fh_export) 1704 goto out; 1705 1706 err = nfserr_perm; 1707 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1708 goto out; 1709 1710 /* cannot use fh_lock as we need deadlock protective ordering 1711 * so do it by hand */ 1712 trap = lock_rename(tdentry, fdentry); 1713 ffhp->fh_locked = tfhp->fh_locked = 1; 1714 fill_pre_wcc(ffhp); 1715 fill_pre_wcc(tfhp); 1716 1717 odentry = lookup_one_len(fname, fdentry, flen); 1718 host_err = PTR_ERR(odentry); 1719 if (IS_ERR(odentry)) 1720 goto out_nfserr; 1721 1722 host_err = -ENOENT; 1723 if (!odentry->d_inode) 1724 goto out_dput_old; 1725 host_err = -EINVAL; 1726 if (odentry == trap) 1727 goto out_dput_old; 1728 1729 ndentry = lookup_one_len(tname, tdentry, tlen); 1730 host_err = PTR_ERR(ndentry); 1731 if (IS_ERR(ndentry)) 1732 goto out_dput_old; 1733 host_err = -ENOTEMPTY; 1734 if (ndentry == trap) 1735 goto out_dput_new; 1736 1737 host_err = -EXDEV; 1738 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) 1739 goto out_dput_new; 1740 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt); 1741 if (host_err) 1742 goto out_dput_new; 1743 1744 host_err = nfsd_break_lease(odentry->d_inode); 1745 if (host_err) 1746 goto out_drop_write; 1747 host_err = vfs_rename(fdir, odentry, tdir, ndentry); 1748 if (!host_err) { 1749 host_err = commit_metadata(tfhp); 1750 if (!host_err) 1751 host_err = commit_metadata(ffhp); 1752 } 1753 out_drop_write: 1754 mnt_drop_write(ffhp->fh_export->ex_path.mnt); 1755 out_dput_new: 1756 dput(ndentry); 1757 out_dput_old: 1758 dput(odentry); 1759 out_nfserr: 1760 err = nfserrno(host_err); 1761 1762 /* we cannot reply on fh_unlock on the two filehandles, 1763 * as that would do the wrong thing if the two directories 1764 * were the same, so again we do it by hand 1765 */ 1766 fill_post_wcc(ffhp); 1767 fill_post_wcc(tfhp); 1768 unlock_rename(tdentry, fdentry); 1769 ffhp->fh_locked = tfhp->fh_locked = 0; 1770 1771 out: 1772 return err; 1773 } 1774 1775 /* 1776 * Unlink a file or directory 1777 * N.B. After this call fhp needs an fh_put 1778 */ 1779 __be32 1780 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1781 char *fname, int flen) 1782 { 1783 struct dentry *dentry, *rdentry; 1784 struct inode *dirp; 1785 __be32 err; 1786 int host_err; 1787 1788 err = nfserr_acces; 1789 if (!flen || isdotent(fname, flen)) 1790 goto out; 1791 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); 1792 if (err) 1793 goto out; 1794 1795 fh_lock_nested(fhp, I_MUTEX_PARENT); 1796 dentry = fhp->fh_dentry; 1797 dirp = dentry->d_inode; 1798 1799 rdentry = lookup_one_len(fname, dentry, flen); 1800 host_err = PTR_ERR(rdentry); 1801 if (IS_ERR(rdentry)) 1802 goto out_nfserr; 1803 1804 if (!rdentry->d_inode) { 1805 dput(rdentry); 1806 err = nfserr_noent; 1807 goto out; 1808 } 1809 1810 if (!type) 1811 type = rdentry->d_inode->i_mode & S_IFMT; 1812 1813 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1814 if (host_err) 1815 goto out_nfserr; 1816 1817 host_err = nfsd_break_lease(rdentry->d_inode); 1818 if (host_err) 1819 goto out_put; 1820 if (type != S_IFDIR) 1821 host_err = vfs_unlink(dirp, rdentry); 1822 else 1823 host_err = vfs_rmdir(dirp, rdentry); 1824 out_put: 1825 dput(rdentry); 1826 1827 if (!host_err) 1828 host_err = commit_metadata(fhp); 1829 1830 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1831 out_nfserr: 1832 err = nfserrno(host_err); 1833 out: 1834 return err; 1835 } 1836 1837 /* 1838 * We do this buffering because we must not call back into the file 1839 * system's ->lookup() method from the filldir callback. That may well 1840 * deadlock a number of file systems. 1841 * 1842 * This is based heavily on the implementation of same in XFS. 1843 */ 1844 struct buffered_dirent { 1845 u64 ino; 1846 loff_t offset; 1847 int namlen; 1848 unsigned int d_type; 1849 char name[]; 1850 }; 1851 1852 struct readdir_data { 1853 char *dirent; 1854 size_t used; 1855 int full; 1856 }; 1857 1858 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, 1859 loff_t offset, u64 ino, unsigned int d_type) 1860 { 1861 struct readdir_data *buf = __buf; 1862 struct buffered_dirent *de = (void *)(buf->dirent + buf->used); 1863 unsigned int reclen; 1864 1865 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); 1866 if (buf->used + reclen > PAGE_SIZE) { 1867 buf->full = 1; 1868 return -EINVAL; 1869 } 1870 1871 de->namlen = namlen; 1872 de->offset = offset; 1873 de->ino = ino; 1874 de->d_type = d_type; 1875 memcpy(de->name, name, namlen); 1876 buf->used += reclen; 1877 1878 return 0; 1879 } 1880 1881 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, 1882 struct readdir_cd *cdp, loff_t *offsetp) 1883 { 1884 struct readdir_data buf; 1885 struct buffered_dirent *de; 1886 int host_err; 1887 int size; 1888 loff_t offset; 1889 1890 buf.dirent = (void *)__get_free_page(GFP_KERNEL); 1891 if (!buf.dirent) 1892 return nfserrno(-ENOMEM); 1893 1894 offset = *offsetp; 1895 1896 while (1) { 1897 struct inode *dir_inode = file->f_path.dentry->d_inode; 1898 unsigned int reclen; 1899 1900 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1901 buf.used = 0; 1902 buf.full = 0; 1903 1904 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf); 1905 if (buf.full) 1906 host_err = 0; 1907 1908 if (host_err < 0) 1909 break; 1910 1911 size = buf.used; 1912 1913 if (!size) 1914 break; 1915 1916 /* 1917 * Various filldir functions may end up calling back into 1918 * lookup_one_len() and the file system's ->lookup() method. 1919 * These expect i_mutex to be held, as it would within readdir. 1920 */ 1921 host_err = mutex_lock_killable(&dir_inode->i_mutex); 1922 if (host_err) 1923 break; 1924 1925 de = (struct buffered_dirent *)buf.dirent; 1926 while (size > 0) { 1927 offset = de->offset; 1928 1929 if (func(cdp, de->name, de->namlen, de->offset, 1930 de->ino, de->d_type)) 1931 break; 1932 1933 if (cdp->err != nfs_ok) 1934 break; 1935 1936 reclen = ALIGN(sizeof(*de) + de->namlen, 1937 sizeof(u64)); 1938 size -= reclen; 1939 de = (struct buffered_dirent *)((char *)de + reclen); 1940 } 1941 mutex_unlock(&dir_inode->i_mutex); 1942 if (size > 0) /* We bailed out early */ 1943 break; 1944 1945 offset = vfs_llseek(file, 0, SEEK_CUR); 1946 } 1947 1948 free_page((unsigned long)(buf.dirent)); 1949 1950 if (host_err) 1951 return nfserrno(host_err); 1952 1953 *offsetp = offset; 1954 return cdp->err; 1955 } 1956 1957 /* 1958 * Read entries from a directory. 1959 * The NFSv3/4 verifier we ignore for now. 1960 */ 1961 __be32 1962 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 1963 struct readdir_cd *cdp, filldir_t func) 1964 { 1965 __be32 err; 1966 struct file *file; 1967 loff_t offset = *offsetp; 1968 1969 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file); 1970 if (err) 1971 goto out; 1972 1973 offset = vfs_llseek(file, offset, 0); 1974 if (offset < 0) { 1975 err = nfserrno((int)offset); 1976 goto out_close; 1977 } 1978 1979 err = nfsd_buffered_readdir(file, func, cdp, offsetp); 1980 1981 if (err == nfserr_eof || err == nfserr_toosmall) 1982 err = nfs_ok; /* can still be found in ->err */ 1983 out_close: 1984 nfsd_close(file); 1985 out: 1986 return err; 1987 } 1988 1989 /* 1990 * Get file system stats 1991 * N.B. After this call fhp needs an fh_put 1992 */ 1993 __be32 1994 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) 1995 { 1996 __be32 err; 1997 1998 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); 1999 if (!err) { 2000 struct path path = { 2001 .mnt = fhp->fh_export->ex_path.mnt, 2002 .dentry = fhp->fh_dentry, 2003 }; 2004 if (vfs_statfs(&path, stat)) 2005 err = nfserr_io; 2006 } 2007 return err; 2008 } 2009 2010 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) 2011 { 2012 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; 2013 } 2014 2015 /* 2016 * Check for a user's access permissions to this inode. 2017 */ 2018 __be32 2019 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, 2020 struct dentry *dentry, int acc) 2021 { 2022 struct inode *inode = dentry->d_inode; 2023 int err; 2024 2025 if (acc == NFSD_MAY_NOP) 2026 return 0; 2027 #if 0 2028 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 2029 acc, 2030 (acc & NFSD_MAY_READ)? " read" : "", 2031 (acc & NFSD_MAY_WRITE)? " write" : "", 2032 (acc & NFSD_MAY_EXEC)? " exec" : "", 2033 (acc & NFSD_MAY_SATTR)? " sattr" : "", 2034 (acc & NFSD_MAY_TRUNC)? " trunc" : "", 2035 (acc & NFSD_MAY_LOCK)? " lock" : "", 2036 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", 2037 inode->i_mode, 2038 IS_IMMUTABLE(inode)? " immut" : "", 2039 IS_APPEND(inode)? " append" : "", 2040 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); 2041 dprintk(" owner %d/%d user %d/%d\n", 2042 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); 2043 #endif 2044 2045 /* Normally we reject any write/sattr etc access on a read-only file 2046 * system. But if it is IRIX doing check on write-access for a 2047 * device special file, we ignore rofs. 2048 */ 2049 if (!(acc & NFSD_MAY_LOCAL_ACCESS)) 2050 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { 2051 if (exp_rdonly(rqstp, exp) || 2052 __mnt_is_readonly(exp->ex_path.mnt)) 2053 return nfserr_rofs; 2054 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) 2055 return nfserr_perm; 2056 } 2057 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) 2058 return nfserr_perm; 2059 2060 if (acc & NFSD_MAY_LOCK) { 2061 /* If we cannot rely on authentication in NLM requests, 2062 * just allow locks, otherwise require read permission, or 2063 * ownership 2064 */ 2065 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 2066 return 0; 2067 else 2068 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE; 2069 } 2070 /* 2071 * The file owner always gets access permission for accesses that 2072 * would normally be checked at open time. This is to make 2073 * file access work even when the client has done a fchmod(fd, 0). 2074 * 2075 * However, `cp foo bar' should fail nevertheless when bar is 2076 * readonly. A sensible way to do this might be to reject all 2077 * attempts to truncate a read-only file, because a creat() call 2078 * always implies file truncation. 2079 * ... but this isn't really fair. A process may reasonably call 2080 * ftruncate on an open file descriptor on a file with perm 000. 2081 * We must trust the client to do permission checking - using "ACCESS" 2082 * with NFSv3. 2083 */ 2084 if ((acc & NFSD_MAY_OWNER_OVERRIDE) && 2085 inode->i_uid == current_fsuid()) 2086 return 0; 2087 2088 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ 2089 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); 2090 2091 /* Allow read access to binaries even when mode 111 */ 2092 if (err == -EACCES && S_ISREG(inode->i_mode) && 2093 acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE)) 2094 err = inode_permission(inode, MAY_EXEC); 2095 2096 return err? nfserrno(err) : 0; 2097 } 2098 2099 void 2100 nfsd_racache_shutdown(void) 2101 { 2102 struct raparms *raparm, *last_raparm; 2103 unsigned int i; 2104 2105 dprintk("nfsd: freeing readahead buffers.\n"); 2106 2107 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2108 raparm = raparm_hash[i].pb_head; 2109 while(raparm) { 2110 last_raparm = raparm; 2111 raparm = raparm->p_next; 2112 kfree(last_raparm); 2113 } 2114 raparm_hash[i].pb_head = NULL; 2115 } 2116 } 2117 /* 2118 * Initialize readahead param cache 2119 */ 2120 int 2121 nfsd_racache_init(int cache_size) 2122 { 2123 int i; 2124 int j = 0; 2125 int nperbucket; 2126 struct raparms **raparm = NULL; 2127 2128 2129 if (raparm_hash[0].pb_head) 2130 return 0; 2131 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE); 2132 if (nperbucket < 2) 2133 nperbucket = 2; 2134 cache_size = nperbucket * RAPARM_HASH_SIZE; 2135 2136 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); 2137 2138 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2139 spin_lock_init(&raparm_hash[i].pb_lock); 2140 2141 raparm = &raparm_hash[i].pb_head; 2142 for (j = 0; j < nperbucket; j++) { 2143 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL); 2144 if (!*raparm) 2145 goto out_nomem; 2146 raparm = &(*raparm)->p_next; 2147 } 2148 *raparm = NULL; 2149 } 2150 2151 nfsdstats.ra_size = cache_size; 2152 return 0; 2153 2154 out_nomem: 2155 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n"); 2156 nfsd_racache_shutdown(); 2157 return -ENOMEM; 2158 } 2159 2160 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 2161 struct posix_acl * 2162 nfsd_get_posix_acl(struct svc_fh *fhp, int type) 2163 { 2164 struct inode *inode = fhp->fh_dentry->d_inode; 2165 char *name; 2166 void *value = NULL; 2167 ssize_t size; 2168 struct posix_acl *acl; 2169 2170 if (!IS_POSIXACL(inode)) 2171 return ERR_PTR(-EOPNOTSUPP); 2172 2173 switch (type) { 2174 case ACL_TYPE_ACCESS: 2175 name = POSIX_ACL_XATTR_ACCESS; 2176 break; 2177 case ACL_TYPE_DEFAULT: 2178 name = POSIX_ACL_XATTR_DEFAULT; 2179 break; 2180 default: 2181 return ERR_PTR(-EOPNOTSUPP); 2182 } 2183 2184 size = nfsd_getxattr(fhp->fh_dentry, name, &value); 2185 if (size < 0) 2186 return ERR_PTR(size); 2187 2188 acl = posix_acl_from_xattr(value, size); 2189 kfree(value); 2190 return acl; 2191 } 2192 2193 int 2194 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) 2195 { 2196 struct inode *inode = fhp->fh_dentry->d_inode; 2197 char *name; 2198 void *value = NULL; 2199 size_t size; 2200 int error; 2201 2202 if (!IS_POSIXACL(inode) || 2203 !inode->i_op->setxattr || !inode->i_op->removexattr) 2204 return -EOPNOTSUPP; 2205 switch(type) { 2206 case ACL_TYPE_ACCESS: 2207 name = POSIX_ACL_XATTR_ACCESS; 2208 break; 2209 case ACL_TYPE_DEFAULT: 2210 name = POSIX_ACL_XATTR_DEFAULT; 2211 break; 2212 default: 2213 return -EOPNOTSUPP; 2214 } 2215 2216 if (acl && acl->a_count) { 2217 size = posix_acl_xattr_size(acl->a_count); 2218 value = kmalloc(size, GFP_KERNEL); 2219 if (!value) 2220 return -ENOMEM; 2221 error = posix_acl_to_xattr(acl, value, size); 2222 if (error < 0) 2223 goto getout; 2224 size = error; 2225 } else 2226 size = 0; 2227 2228 error = mnt_want_write(fhp->fh_export->ex_path.mnt); 2229 if (error) 2230 goto getout; 2231 if (size) 2232 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); 2233 else { 2234 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) 2235 error = 0; 2236 else { 2237 error = vfs_removexattr(fhp->fh_dentry, name); 2238 if (error == -ENODATA) 2239 error = 0; 2240 } 2241 } 2242 mnt_drop_write(fhp->fh_export->ex_path.mnt); 2243 2244 getout: 2245 kfree(value); 2246 return error; 2247 } 2248 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 2249