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 #include <linux/security.h> 32 33 #ifdef CONFIG_NFSD_V3 34 #include "xdr3.h" 35 #endif /* CONFIG_NFSD_V3 */ 36 37 #ifdef CONFIG_NFSD_V4 38 #include "acl.h" 39 #include "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 err = follow_down(&path); 92 if (err < 0) 93 goto out; 94 95 exp2 = rqst_exp_get_by_name(rqstp, &path); 96 if (IS_ERR(exp2)) { 97 err = PTR_ERR(exp2); 98 /* 99 * We normally allow NFS clients to continue 100 * "underneath" a mountpoint that is not exported. 101 * The exception is V4ROOT, where no traversal is ever 102 * allowed without an explicit export of the new 103 * directory. 104 */ 105 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT)) 106 err = 0; 107 path_put(&path); 108 goto out; 109 } 110 if (nfsd_v4client(rqstp) || 111 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) { 112 /* successfully crossed mount point */ 113 /* 114 * This is subtle: path.dentry is *not* on path.mnt 115 * at this point. The only reason we are safe is that 116 * original mnt is pinned down by exp, so we should 117 * put path *before* putting exp 118 */ 119 *dpp = path.dentry; 120 path.dentry = dentry; 121 *expp = exp2; 122 exp2 = exp; 123 } 124 path_put(&path); 125 exp_put(exp2); 126 out: 127 return err; 128 } 129 130 static void follow_to_parent(struct path *path) 131 { 132 struct dentry *dp; 133 134 while (path->dentry == path->mnt->mnt_root && follow_up(path)) 135 ; 136 dp = dget_parent(path->dentry); 137 dput(path->dentry); 138 path->dentry = dp; 139 } 140 141 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp) 142 { 143 struct svc_export *exp2; 144 struct path path = {.mnt = mntget((*exp)->ex_path.mnt), 145 .dentry = dget(dparent)}; 146 147 follow_to_parent(&path); 148 149 exp2 = rqst_exp_parent(rqstp, &path); 150 if (PTR_ERR(exp2) == -ENOENT) { 151 *dentryp = dget(dparent); 152 } else if (IS_ERR(exp2)) { 153 path_put(&path); 154 return PTR_ERR(exp2); 155 } else { 156 *dentryp = dget(path.dentry); 157 exp_put(*exp); 158 *exp = exp2; 159 } 160 path_put(&path); 161 return 0; 162 } 163 164 /* 165 * For nfsd purposes, we treat V4ROOT exports as though there was an 166 * export at *every* directory. 167 */ 168 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) 169 { 170 if (d_mountpoint(dentry)) 171 return 1; 172 if (nfsd4_is_junction(dentry)) 173 return 1; 174 if (!(exp->ex_flags & NFSEXP_V4ROOT)) 175 return 0; 176 return dentry->d_inode != NULL; 177 } 178 179 __be32 180 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, 181 const char *name, unsigned int len, 182 struct svc_export **exp_ret, struct dentry **dentry_ret) 183 { 184 struct svc_export *exp; 185 struct dentry *dparent; 186 struct dentry *dentry; 187 int host_err; 188 189 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); 190 191 dparent = fhp->fh_dentry; 192 exp = fhp->fh_export; 193 exp_get(exp); 194 195 /* Lookup the name, but don't follow links */ 196 if (isdotent(name, len)) { 197 if (len==1) 198 dentry = dget(dparent); 199 else if (dparent != exp->ex_path.dentry) 200 dentry = dget_parent(dparent); 201 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp)) 202 dentry = dget(dparent); /* .. == . just like at / */ 203 else { 204 /* checking mountpoint crossing is very different when stepping up */ 205 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry); 206 if (host_err) 207 goto out_nfserr; 208 } 209 } else { 210 fh_lock(fhp); 211 dentry = lookup_one_len(name, dparent, len); 212 host_err = PTR_ERR(dentry); 213 if (IS_ERR(dentry)) 214 goto out_nfserr; 215 /* 216 * check if we have crossed a mount point ... 217 */ 218 if (nfsd_mountpoint(dentry, exp)) { 219 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) { 220 dput(dentry); 221 goto out_nfserr; 222 } 223 } 224 } 225 *dentry_ret = dentry; 226 *exp_ret = exp; 227 return 0; 228 229 out_nfserr: 230 exp_put(exp); 231 return nfserrno(host_err); 232 } 233 234 /* 235 * Look up one component of a pathname. 236 * N.B. After this call _both_ fhp and resfh need an fh_put 237 * 238 * If the lookup would cross a mountpoint, and the mounted filesystem 239 * is exported to the client with NFSEXP_NOHIDE, then the lookup is 240 * accepted as it stands and the mounted directory is 241 * returned. Otherwise the covered directory is returned. 242 * NOTE: this mountpoint crossing is not supported properly by all 243 * clients and is explicitly disallowed for NFSv3 244 * NeilBrown <neilb@cse.unsw.edu.au> 245 */ 246 __be32 247 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, 248 unsigned int len, struct svc_fh *resfh) 249 { 250 struct svc_export *exp; 251 struct dentry *dentry; 252 __be32 err; 253 254 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); 255 if (err) 256 return err; 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 * Go over the attributes and take care of the small differences between 302 * NFS semantics and what Linux expects. 303 */ 304 static void 305 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap) 306 { 307 /* 308 * NFSv2 does not differentiate between "set-[ac]time-to-now" 309 * which only requires access, and "set-[ac]time-to-X" which 310 * requires ownership. 311 * So if it looks like it might be "set both to the same time which 312 * is close to now", and if inode_change_ok fails, then we 313 * convert to "set to now" instead of "set to explicit time" 314 * 315 * We only call inode_change_ok as the last test as technically 316 * it is not an interface that we should be using. 317 */ 318 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 319 #define MAX_TOUCH_TIME_ERROR (30*60) 320 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && 321 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) { 322 /* 323 * Looks probable. 324 * 325 * Now just make sure time is in the right ballpark. 326 * Solaris, at least, doesn't seem to care what the time 327 * request is. We require it be within 30 minutes of now. 328 */ 329 time_t delta = iap->ia_atime.tv_sec - get_seconds(); 330 if (delta < 0) 331 delta = -delta; 332 if (delta < MAX_TOUCH_TIME_ERROR && 333 inode_change_ok(inode, iap) != 0) { 334 /* 335 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME. 336 * This will cause notify_change to set these times 337 * to "now" 338 */ 339 iap->ia_valid &= ~BOTH_TIME_SET; 340 } 341 } 342 343 /* sanitize the mode change */ 344 if (iap->ia_valid & ATTR_MODE) { 345 iap->ia_mode &= S_IALLUGO; 346 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); 347 } 348 349 /* Revoke setuid/setgid on chown */ 350 if (!S_ISDIR(inode->i_mode) && 351 (((iap->ia_valid & ATTR_UID) && !uid_eq(iap->ia_uid, inode->i_uid)) || 352 ((iap->ia_valid & ATTR_GID) && !gid_eq(iap->ia_gid, inode->i_gid)))) { 353 iap->ia_valid |= ATTR_KILL_PRIV; 354 if (iap->ia_valid & ATTR_MODE) { 355 /* we're setting mode too, just clear the s*id bits */ 356 iap->ia_mode &= ~S_ISUID; 357 if (iap->ia_mode & S_IXGRP) 358 iap->ia_mode &= ~S_ISGID; 359 } else { 360 /* set ATTR_KILL_* bits and let VFS handle it */ 361 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID); 362 } 363 } 364 } 365 366 static __be32 367 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp, 368 struct iattr *iap) 369 { 370 struct inode *inode = fhp->fh_dentry->d_inode; 371 int host_err; 372 373 if (iap->ia_size < inode->i_size) { 374 __be32 err; 375 376 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 377 NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE); 378 if (err) 379 return err; 380 } 381 382 host_err = get_write_access(inode); 383 if (host_err) 384 goto out_nfserrno; 385 386 host_err = locks_verify_truncate(inode, NULL, iap->ia_size); 387 if (host_err) 388 goto out_put_write_access; 389 return 0; 390 391 out_put_write_access: 392 put_write_access(inode); 393 out_nfserrno: 394 return nfserrno(host_err); 395 } 396 397 /* 398 * Set various file attributes. After this call fhp needs an fh_put. 399 */ 400 __be32 401 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 402 int check_guard, time_t guardtime) 403 { 404 struct dentry *dentry; 405 struct inode *inode; 406 int accmode = NFSD_MAY_SATTR; 407 umode_t ftype = 0; 408 __be32 err; 409 int host_err; 410 int size_change = 0; 411 412 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 413 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; 414 if (iap->ia_valid & ATTR_SIZE) 415 ftype = S_IFREG; 416 417 /* Get inode */ 418 err = fh_verify(rqstp, fhp, ftype, accmode); 419 if (err) 420 goto out; 421 422 dentry = fhp->fh_dentry; 423 inode = dentry->d_inode; 424 425 /* Ignore any mode updates on symlinks */ 426 if (S_ISLNK(inode->i_mode)) 427 iap->ia_valid &= ~ATTR_MODE; 428 429 if (!iap->ia_valid) 430 goto out; 431 432 nfsd_sanitize_attrs(inode, iap); 433 434 /* 435 * The size case is special, it changes the file in addition to the 436 * attributes. 437 */ 438 if (iap->ia_valid & ATTR_SIZE) { 439 err = nfsd_get_write_access(rqstp, fhp, iap); 440 if (err) 441 goto out; 442 size_change = 1; 443 } 444 445 iap->ia_valid |= ATTR_CTIME; 446 447 if (check_guard && guardtime != inode->i_ctime.tv_sec) { 448 err = nfserr_notsync; 449 goto out_put_write_access; 450 } 451 452 host_err = nfsd_break_lease(inode); 453 if (host_err) 454 goto out_put_write_access_nfserror; 455 456 fh_lock(fhp); 457 host_err = notify_change(dentry, iap, NULL); 458 fh_unlock(fhp); 459 460 out_put_write_access_nfserror: 461 err = nfserrno(host_err); 462 out_put_write_access: 463 if (size_change) 464 put_write_access(inode); 465 if (!err) 466 commit_metadata(fhp); 467 out: 468 return err; 469 } 470 471 #if defined(CONFIG_NFSD_V4) 472 /* 473 * NFS junction information is stored in an extended attribute. 474 */ 475 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs" 476 477 /** 478 * nfsd4_is_junction - Test if an object could be an NFS junction 479 * 480 * @dentry: object to test 481 * 482 * Returns 1 if "dentry" appears to contain NFS junction information. 483 * Otherwise 0 is returned. 484 */ 485 int nfsd4_is_junction(struct dentry *dentry) 486 { 487 struct inode *inode = dentry->d_inode; 488 489 if (inode == NULL) 490 return 0; 491 if (inode->i_mode & S_IXUGO) 492 return 0; 493 if (!(inode->i_mode & S_ISVTX)) 494 return 0; 495 if (vfs_getxattr(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0) 496 return 0; 497 return 1; 498 } 499 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL 500 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp, 501 struct xdr_netobj *label) 502 { 503 __be32 error; 504 int host_error; 505 struct dentry *dentry; 506 507 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); 508 if (error) 509 return error; 510 511 dentry = fhp->fh_dentry; 512 513 mutex_lock(&dentry->d_inode->i_mutex); 514 host_error = security_inode_setsecctx(dentry, label->data, label->len); 515 mutex_unlock(&dentry->d_inode->i_mutex); 516 return nfserrno(host_error); 517 } 518 #else 519 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp, 520 struct xdr_netobj *label) 521 { 522 return nfserr_notsupp; 523 } 524 #endif 525 526 #endif /* defined(CONFIG_NFSD_V4) */ 527 528 #ifdef CONFIG_NFSD_V3 529 /* 530 * Check server access rights to a file system object 531 */ 532 struct accessmap { 533 u32 access; 534 int how; 535 }; 536 static struct accessmap nfs3_regaccess[] = { 537 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 538 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 539 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, 540 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, 541 542 { 0, 0 } 543 }; 544 545 static struct accessmap nfs3_diraccess[] = { 546 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 547 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, 548 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, 549 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, 550 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, 551 552 { 0, 0 } 553 }; 554 555 static struct accessmap nfs3_anyaccess[] = { 556 /* Some clients - Solaris 2.6 at least, make an access call 557 * to the server to check for access for things like /dev/null 558 * (which really, the server doesn't care about). So 559 * We provide simple access checking for them, looking 560 * mainly at mode bits, and we make sure to ignore read-only 561 * filesystem checks 562 */ 563 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 564 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 565 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 566 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 567 568 { 0, 0 } 569 }; 570 571 __be32 572 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 573 { 574 struct accessmap *map; 575 struct svc_export *export; 576 struct dentry *dentry; 577 u32 query, result = 0, sresult = 0; 578 __be32 error; 579 580 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP); 581 if (error) 582 goto out; 583 584 export = fhp->fh_export; 585 dentry = fhp->fh_dentry; 586 587 if (S_ISREG(dentry->d_inode->i_mode)) 588 map = nfs3_regaccess; 589 else if (S_ISDIR(dentry->d_inode->i_mode)) 590 map = nfs3_diraccess; 591 else 592 map = nfs3_anyaccess; 593 594 595 query = *access; 596 for (; map->access; map++) { 597 if (map->access & query) { 598 __be32 err2; 599 600 sresult |= map->access; 601 602 err2 = nfsd_permission(rqstp, export, dentry, map->how); 603 switch (err2) { 604 case nfs_ok: 605 result |= map->access; 606 break; 607 608 /* the following error codes just mean the access was not allowed, 609 * rather than an error occurred */ 610 case nfserr_rofs: 611 case nfserr_acces: 612 case nfserr_perm: 613 /* simply don't "or" in the access bit. */ 614 break; 615 default: 616 error = err2; 617 goto out; 618 } 619 } 620 } 621 *access = result; 622 if (supported) 623 *supported = sresult; 624 625 out: 626 return error; 627 } 628 #endif /* CONFIG_NFSD_V3 */ 629 630 static int nfsd_open_break_lease(struct inode *inode, int access) 631 { 632 unsigned int mode; 633 634 if (access & NFSD_MAY_NOT_BREAK_LEASE) 635 return 0; 636 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY; 637 return break_lease(inode, mode | O_NONBLOCK); 638 } 639 640 /* 641 * Open an existing file or directory. 642 * The may_flags argument indicates the type of open (read/write/lock) 643 * and additional flags. 644 * N.B. After this call fhp needs an fh_put 645 */ 646 __be32 647 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, 648 int may_flags, struct file **filp) 649 { 650 struct path path; 651 struct inode *inode; 652 int flags = O_RDONLY|O_LARGEFILE; 653 __be32 err; 654 int host_err = 0; 655 656 validate_process_creds(); 657 658 /* 659 * If we get here, then the client has already done an "open", 660 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 661 * in case a chmod has now revoked permission. 662 * 663 * Arguably we should also allow the owner override for 664 * directories, but we never have and it doesn't seem to have 665 * caused anyone a problem. If we were to change this, note 666 * also that our filldir callbacks would need a variant of 667 * lookup_one_len that doesn't check permissions. 668 */ 669 if (type == S_IFREG) 670 may_flags |= NFSD_MAY_OWNER_OVERRIDE; 671 err = fh_verify(rqstp, fhp, type, may_flags); 672 if (err) 673 goto out; 674 675 path.mnt = fhp->fh_export->ex_path.mnt; 676 path.dentry = fhp->fh_dentry; 677 inode = path.dentry->d_inode; 678 679 /* Disallow write access to files with the append-only bit set 680 * or any access when mandatory locking enabled 681 */ 682 err = nfserr_perm; 683 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE)) 684 goto out; 685 /* 686 * We must ignore files (but only files) which might have mandatory 687 * locks on them because there is no way to know if the accesser has 688 * the lock. 689 */ 690 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode)) 691 goto out; 692 693 if (!inode->i_fop) 694 goto out; 695 696 host_err = nfsd_open_break_lease(inode, may_flags); 697 if (host_err) /* NOMEM or WOULDBLOCK */ 698 goto out_nfserr; 699 700 if (may_flags & NFSD_MAY_WRITE) { 701 if (may_flags & NFSD_MAY_READ) 702 flags = O_RDWR|O_LARGEFILE; 703 else 704 flags = O_WRONLY|O_LARGEFILE; 705 } 706 *filp = dentry_open(&path, flags, current_cred()); 707 if (IS_ERR(*filp)) { 708 host_err = PTR_ERR(*filp); 709 *filp = NULL; 710 } else { 711 host_err = ima_file_check(*filp, may_flags); 712 713 if (may_flags & NFSD_MAY_64BIT_COOKIE) 714 (*filp)->f_mode |= FMODE_64BITHASH; 715 else 716 (*filp)->f_mode |= FMODE_32BITHASH; 717 } 718 719 out_nfserr: 720 err = nfserrno(host_err); 721 out: 722 validate_process_creds(); 723 return err; 724 } 725 726 /* 727 * Close a file. 728 */ 729 void 730 nfsd_close(struct file *filp) 731 { 732 fput(filp); 733 } 734 735 /* 736 * Obtain the readahead parameters for the file 737 * specified by (dev, ino). 738 */ 739 740 static inline struct raparms * 741 nfsd_get_raparms(dev_t dev, ino_t ino) 742 { 743 struct raparms *ra, **rap, **frap = NULL; 744 int depth = 0; 745 unsigned int hash; 746 struct raparm_hbucket *rab; 747 748 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK; 749 rab = &raparm_hash[hash]; 750 751 spin_lock(&rab->pb_lock); 752 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) { 753 if (ra->p_ino == ino && ra->p_dev == dev) 754 goto found; 755 depth++; 756 if (ra->p_count == 0) 757 frap = rap; 758 } 759 depth = nfsdstats.ra_size; 760 if (!frap) { 761 spin_unlock(&rab->pb_lock); 762 return NULL; 763 } 764 rap = frap; 765 ra = *frap; 766 ra->p_dev = dev; 767 ra->p_ino = ino; 768 ra->p_set = 0; 769 ra->p_hindex = hash; 770 found: 771 if (rap != &rab->pb_head) { 772 *rap = ra->p_next; 773 ra->p_next = rab->pb_head; 774 rab->pb_head = ra; 775 } 776 ra->p_count++; 777 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 778 spin_unlock(&rab->pb_lock); 779 return ra; 780 } 781 782 /* 783 * Grab and keep cached pages associated with a file in the svc_rqst 784 * so that they can be passed to the network sendmsg/sendpage routines 785 * directly. They will be released after the sending has completed. 786 */ 787 static int 788 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 789 struct splice_desc *sd) 790 { 791 struct svc_rqst *rqstp = sd->u.data; 792 struct page **pp = rqstp->rq_next_page; 793 struct page *page = buf->page; 794 size_t size; 795 796 size = sd->len; 797 798 if (rqstp->rq_res.page_len == 0) { 799 get_page(page); 800 put_page(*rqstp->rq_next_page); 801 *(rqstp->rq_next_page++) = page; 802 rqstp->rq_res.page_base = buf->offset; 803 rqstp->rq_res.page_len = size; 804 } else if (page != pp[-1]) { 805 get_page(page); 806 if (*rqstp->rq_next_page) 807 put_page(*rqstp->rq_next_page); 808 *(rqstp->rq_next_page++) = page; 809 rqstp->rq_res.page_len += size; 810 } else 811 rqstp->rq_res.page_len += size; 812 813 return size; 814 } 815 816 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, 817 struct splice_desc *sd) 818 { 819 return __splice_from_pipe(pipe, sd, nfsd_splice_actor); 820 } 821 822 static __be32 823 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 824 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 825 { 826 mm_segment_t oldfs; 827 __be32 err; 828 int host_err; 829 830 err = nfserr_perm; 831 832 if (file->f_op->splice_read && rqstp->rq_splice_ok) { 833 struct splice_desc sd = { 834 .len = 0, 835 .total_len = *count, 836 .pos = offset, 837 .u.data = rqstp, 838 }; 839 840 rqstp->rq_next_page = rqstp->rq_respages + 1; 841 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); 842 } else { 843 oldfs = get_fs(); 844 set_fs(KERNEL_DS); 845 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 846 set_fs(oldfs); 847 } 848 849 if (host_err >= 0) { 850 nfsdstats.io_read += host_err; 851 *count = host_err; 852 err = 0; 853 fsnotify_access(file); 854 } else 855 err = nfserrno(host_err); 856 return err; 857 } 858 859 static void kill_suid(struct dentry *dentry) 860 { 861 struct iattr ia; 862 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; 863 864 mutex_lock(&dentry->d_inode->i_mutex); 865 /* 866 * Note we call this on write, so notify_change will not 867 * encounter any conflicting delegations: 868 */ 869 notify_change(dentry, &ia, NULL); 870 mutex_unlock(&dentry->d_inode->i_mutex); 871 } 872 873 /* 874 * Gathered writes: If another process is currently writing to the file, 875 * there's a high chance this is another nfsd (triggered by a bulk write 876 * from a client's biod). Rather than syncing the file with each write 877 * request, we sleep for 10 msec. 878 * 879 * I don't know if this roughly approximates C. Juszak's idea of 880 * gathered writes, but it's a nice and simple solution (IMHO), and it 881 * seems to work:-) 882 * 883 * Note: we do this only in the NFSv2 case, since v3 and higher have a 884 * better tool (separate unstable writes and commits) for solving this 885 * problem. 886 */ 887 static int wait_for_concurrent_writes(struct file *file) 888 { 889 struct inode *inode = file_inode(file); 890 static ino_t last_ino; 891 static dev_t last_dev; 892 int err = 0; 893 894 if (atomic_read(&inode->i_writecount) > 1 895 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 896 dprintk("nfsd: write defer %d\n", task_pid_nr(current)); 897 msleep(10); 898 dprintk("nfsd: write resume %d\n", task_pid_nr(current)); 899 } 900 901 if (inode->i_state & I_DIRTY) { 902 dprintk("nfsd: write sync %d\n", task_pid_nr(current)); 903 err = vfs_fsync(file, 0); 904 } 905 last_ino = inode->i_ino; 906 last_dev = inode->i_sb->s_dev; 907 return err; 908 } 909 910 static __be32 911 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 912 loff_t offset, struct kvec *vec, int vlen, 913 unsigned long *cnt, int *stablep) 914 { 915 struct svc_export *exp; 916 struct dentry *dentry; 917 struct inode *inode; 918 mm_segment_t oldfs; 919 __be32 err = 0; 920 int host_err; 921 int stable = *stablep; 922 int use_wgather; 923 loff_t pos = offset; 924 925 dentry = file->f_path.dentry; 926 inode = dentry->d_inode; 927 exp = fhp->fh_export; 928 929 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); 930 931 if (!EX_ISSYNC(exp)) 932 stable = 0; 933 934 /* Write the data. */ 935 oldfs = get_fs(); set_fs(KERNEL_DS); 936 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos); 937 set_fs(oldfs); 938 if (host_err < 0) 939 goto out_nfserr; 940 *cnt = host_err; 941 nfsdstats.io_write += host_err; 942 fsnotify_modify(file); 943 944 /* clear setuid/setgid flag after write */ 945 if (inode->i_mode & (S_ISUID | S_ISGID)) 946 kill_suid(dentry); 947 948 if (stable) { 949 if (use_wgather) 950 host_err = wait_for_concurrent_writes(file); 951 else 952 host_err = vfs_fsync_range(file, offset, offset+*cnt, 0); 953 } 954 955 out_nfserr: 956 dprintk("nfsd: write complete host_err=%d\n", host_err); 957 if (host_err >= 0) 958 err = 0; 959 else 960 err = nfserrno(host_err); 961 return err; 962 } 963 964 /* 965 * Read data from a file. count must contain the requested read count 966 * on entry. On return, *count contains the number of bytes actually read. 967 * N.B. After this call fhp needs an fh_put 968 */ 969 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 970 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 971 { 972 struct file *file; 973 struct inode *inode; 974 struct raparms *ra; 975 __be32 err; 976 977 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); 978 if (err) 979 return err; 980 981 inode = file_inode(file); 982 983 /* Get readahead parameters */ 984 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 985 986 if (ra && ra->p_set) 987 file->f_ra = ra->p_ra; 988 989 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 990 991 /* Write back readahead params */ 992 if (ra) { 993 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex]; 994 spin_lock(&rab->pb_lock); 995 ra->p_ra = file->f_ra; 996 ra->p_set = 1; 997 ra->p_count--; 998 spin_unlock(&rab->pb_lock); 999 } 1000 1001 nfsd_close(file); 1002 return err; 1003 } 1004 1005 /* As above, but use the provided file descriptor. */ 1006 __be32 1007 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1008 loff_t offset, struct kvec *vec, int vlen, 1009 unsigned long *count) 1010 { 1011 __be32 err; 1012 1013 if (file) { 1014 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1015 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE); 1016 if (err) 1017 goto out; 1018 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1019 } else /* Note file may still be NULL in NFSv4 special stateid case: */ 1020 err = nfsd_read(rqstp, fhp, offset, vec, vlen, count); 1021 out: 1022 return err; 1023 } 1024 1025 /* 1026 * Write data to a file. 1027 * The stable flag requests synchronous writes. 1028 * N.B. After this call fhp needs an fh_put 1029 */ 1030 __be32 1031 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1032 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, 1033 int *stablep) 1034 { 1035 __be32 err = 0; 1036 1037 if (file) { 1038 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1039 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE); 1040 if (err) 1041 goto out; 1042 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1043 stablep); 1044 } else { 1045 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); 1046 if (err) 1047 goto out; 1048 1049 if (cnt) 1050 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1051 cnt, stablep); 1052 nfsd_close(file); 1053 } 1054 out: 1055 return err; 1056 } 1057 1058 #ifdef CONFIG_NFSD_V3 1059 /* 1060 * Commit all pending writes to stable storage. 1061 * 1062 * Note: we only guarantee that data that lies within the range specified 1063 * by the 'offset' and 'count' parameters will be synced. 1064 * 1065 * Unfortunately we cannot lock the file to make sure we return full WCC 1066 * data to the client, as locking happens lower down in the filesystem. 1067 */ 1068 __be32 1069 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1070 loff_t offset, unsigned long count) 1071 { 1072 struct file *file; 1073 loff_t end = LLONG_MAX; 1074 __be32 err = nfserr_inval; 1075 1076 if (offset < 0) 1077 goto out; 1078 if (count != 0) { 1079 end = offset + (loff_t)count - 1; 1080 if (end < offset) 1081 goto out; 1082 } 1083 1084 err = nfsd_open(rqstp, fhp, S_IFREG, 1085 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file); 1086 if (err) 1087 goto out; 1088 if (EX_ISSYNC(fhp->fh_export)) { 1089 int err2 = vfs_fsync_range(file, offset, end, 0); 1090 1091 if (err2 != -EINVAL) 1092 err = nfserrno(err2); 1093 else 1094 err = nfserr_notsupp; 1095 } 1096 1097 nfsd_close(file); 1098 out: 1099 return err; 1100 } 1101 #endif /* CONFIG_NFSD_V3 */ 1102 1103 static __be32 1104 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp, 1105 struct iattr *iap) 1106 { 1107 /* 1108 * Mode has already been set earlier in create: 1109 */ 1110 iap->ia_valid &= ~ATTR_MODE; 1111 /* 1112 * Setting uid/gid works only for root. Irix appears to 1113 * send along the gid on create when it tries to implement 1114 * setgid directories via NFS: 1115 */ 1116 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID)) 1117 iap->ia_valid &= ~(ATTR_UID|ATTR_GID); 1118 if (iap->ia_valid) 1119 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1120 return 0; 1121 } 1122 1123 /* HPUX client sometimes creates a file in mode 000, and sets size to 0. 1124 * setting size to 0 may fail for some specific file systems by the permission 1125 * checking which requires WRITE permission but the mode is 000. 1126 * we ignore the resizing(to 0) on the just new created file, since the size is 1127 * 0 after file created. 1128 * 1129 * call this only after vfs_create() is called. 1130 * */ 1131 static void 1132 nfsd_check_ignore_resizing(struct iattr *iap) 1133 { 1134 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) 1135 iap->ia_valid &= ~ATTR_SIZE; 1136 } 1137 1138 /* 1139 * Create a file (regular, directory, device, fifo); UNIX sockets 1140 * not yet implemented. 1141 * If the response fh has been verified, the parent directory should 1142 * already be locked. Note that the parent directory is left locked. 1143 * 1144 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1145 */ 1146 __be32 1147 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1148 char *fname, int flen, struct iattr *iap, 1149 int type, dev_t rdev, struct svc_fh *resfhp) 1150 { 1151 struct dentry *dentry, *dchild = NULL; 1152 struct inode *dirp; 1153 __be32 err; 1154 __be32 err2; 1155 int host_err; 1156 1157 err = nfserr_perm; 1158 if (!flen) 1159 goto out; 1160 err = nfserr_exist; 1161 if (isdotent(fname, flen)) 1162 goto out; 1163 1164 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1165 if (err) 1166 goto out; 1167 1168 dentry = fhp->fh_dentry; 1169 dirp = dentry->d_inode; 1170 1171 err = nfserr_notdir; 1172 if (!dirp->i_op->lookup) 1173 goto out; 1174 /* 1175 * Check whether the response file handle has been verified yet. 1176 * If it has, the parent directory should already be locked. 1177 */ 1178 if (!resfhp->fh_dentry) { 1179 host_err = fh_want_write(fhp); 1180 if (host_err) 1181 goto out_nfserr; 1182 1183 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1184 fh_lock_nested(fhp, I_MUTEX_PARENT); 1185 dchild = lookup_one_len(fname, dentry, flen); 1186 host_err = PTR_ERR(dchild); 1187 if (IS_ERR(dchild)) 1188 goto out_nfserr; 1189 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1190 if (err) 1191 goto out; 1192 } else { 1193 /* called from nfsd_proc_create */ 1194 dchild = dget(resfhp->fh_dentry); 1195 if (!fhp->fh_locked) { 1196 /* not actually possible */ 1197 printk(KERN_ERR 1198 "nfsd_create: parent %pd2 not locked!\n", 1199 dentry); 1200 err = nfserr_io; 1201 goto out; 1202 } 1203 } 1204 /* 1205 * Make sure the child dentry is still negative ... 1206 */ 1207 err = nfserr_exist; 1208 if (dchild->d_inode) { 1209 dprintk("nfsd_create: dentry %pd/%pd not negative!\n", 1210 dentry, dchild); 1211 goto out; 1212 } 1213 1214 if (!(iap->ia_valid & ATTR_MODE)) 1215 iap->ia_mode = 0; 1216 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1217 1218 err = nfserr_inval; 1219 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) { 1220 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", 1221 type); 1222 goto out; 1223 } 1224 1225 /* 1226 * Get the dir op function pointer. 1227 */ 1228 err = 0; 1229 host_err = 0; 1230 switch (type) { 1231 case S_IFREG: 1232 host_err = vfs_create(dirp, dchild, iap->ia_mode, true); 1233 if (!host_err) 1234 nfsd_check_ignore_resizing(iap); 1235 break; 1236 case S_IFDIR: 1237 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1238 break; 1239 case S_IFCHR: 1240 case S_IFBLK: 1241 case S_IFIFO: 1242 case S_IFSOCK: 1243 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1244 break; 1245 } 1246 if (host_err < 0) 1247 goto out_nfserr; 1248 1249 err = nfsd_create_setattr(rqstp, resfhp, iap); 1250 1251 /* 1252 * nfsd_setattr already committed the child. Transactional filesystems 1253 * had a chance to commit changes for both parent and child 1254 * simultaneously making the following commit_metadata a noop. 1255 */ 1256 err2 = nfserrno(commit_metadata(fhp)); 1257 if (err2) 1258 err = err2; 1259 /* 1260 * Update the file handle to get the new inode info. 1261 */ 1262 if (!err) 1263 err = fh_update(resfhp); 1264 out: 1265 if (dchild && !IS_ERR(dchild)) 1266 dput(dchild); 1267 return err; 1268 1269 out_nfserr: 1270 err = nfserrno(host_err); 1271 goto out; 1272 } 1273 1274 #ifdef CONFIG_NFSD_V3 1275 1276 static inline int nfsd_create_is_exclusive(int createmode) 1277 { 1278 return createmode == NFS3_CREATE_EXCLUSIVE 1279 || createmode == NFS4_CREATE_EXCLUSIVE4_1; 1280 } 1281 1282 /* 1283 * NFSv3 and NFSv4 version of nfsd_create 1284 */ 1285 __be32 1286 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1287 char *fname, int flen, struct iattr *iap, 1288 struct svc_fh *resfhp, int createmode, u32 *verifier, 1289 bool *truncp, bool *created) 1290 { 1291 struct dentry *dentry, *dchild = NULL; 1292 struct inode *dirp; 1293 __be32 err; 1294 int host_err; 1295 __u32 v_mtime=0, v_atime=0; 1296 1297 err = nfserr_perm; 1298 if (!flen) 1299 goto out; 1300 err = nfserr_exist; 1301 if (isdotent(fname, flen)) 1302 goto out; 1303 if (!(iap->ia_valid & ATTR_MODE)) 1304 iap->ia_mode = 0; 1305 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); 1306 if (err) 1307 goto out; 1308 1309 dentry = fhp->fh_dentry; 1310 dirp = dentry->d_inode; 1311 1312 /* Get all the sanity checks out of the way before 1313 * we lock the parent. */ 1314 err = nfserr_notdir; 1315 if (!dirp->i_op->lookup) 1316 goto out; 1317 1318 host_err = fh_want_write(fhp); 1319 if (host_err) 1320 goto out_nfserr; 1321 1322 fh_lock_nested(fhp, I_MUTEX_PARENT); 1323 1324 /* 1325 * Compose the response file handle. 1326 */ 1327 dchild = lookup_one_len(fname, dentry, flen); 1328 host_err = PTR_ERR(dchild); 1329 if (IS_ERR(dchild)) 1330 goto out_nfserr; 1331 1332 /* If file doesn't exist, check for permissions to create one */ 1333 if (!dchild->d_inode) { 1334 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1335 if (err) 1336 goto out; 1337 } 1338 1339 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1340 if (err) 1341 goto out; 1342 1343 if (nfsd_create_is_exclusive(createmode)) { 1344 /* solaris7 gets confused (bugid 4218508) if these have 1345 * the high bit set, so just clear the high bits. If this is 1346 * ever changed to use different attrs for storing the 1347 * verifier, then do_open_lookup() will also need to be fixed 1348 * accordingly. 1349 */ 1350 v_mtime = verifier[0]&0x7fffffff; 1351 v_atime = verifier[1]&0x7fffffff; 1352 } 1353 1354 if (dchild->d_inode) { 1355 err = 0; 1356 1357 switch (createmode) { 1358 case NFS3_CREATE_UNCHECKED: 1359 if (! S_ISREG(dchild->d_inode->i_mode)) 1360 goto out; 1361 else if (truncp) { 1362 /* in nfsv4, we need to treat this case a little 1363 * differently. we don't want to truncate the 1364 * file now; this would be wrong if the OPEN 1365 * fails for some other reason. furthermore, 1366 * if the size is nonzero, we should ignore it 1367 * according to spec! 1368 */ 1369 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1370 } 1371 else { 1372 iap->ia_valid &= ATTR_SIZE; 1373 goto set_attr; 1374 } 1375 break; 1376 case NFS3_CREATE_EXCLUSIVE: 1377 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1378 && dchild->d_inode->i_atime.tv_sec == v_atime 1379 && dchild->d_inode->i_size == 0 ) { 1380 if (created) 1381 *created = 1; 1382 break; 1383 } 1384 case NFS4_CREATE_EXCLUSIVE4_1: 1385 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1386 && dchild->d_inode->i_atime.tv_sec == v_atime 1387 && dchild->d_inode->i_size == 0 ) { 1388 if (created) 1389 *created = 1; 1390 goto set_attr; 1391 } 1392 /* fallthru */ 1393 case NFS3_CREATE_GUARDED: 1394 err = nfserr_exist; 1395 } 1396 fh_drop_write(fhp); 1397 goto out; 1398 } 1399 1400 host_err = vfs_create(dirp, dchild, iap->ia_mode, true); 1401 if (host_err < 0) { 1402 fh_drop_write(fhp); 1403 goto out_nfserr; 1404 } 1405 if (created) 1406 *created = 1; 1407 1408 nfsd_check_ignore_resizing(iap); 1409 1410 if (nfsd_create_is_exclusive(createmode)) { 1411 /* Cram the verifier into atime/mtime */ 1412 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1413 | ATTR_MTIME_SET|ATTR_ATIME_SET; 1414 /* XXX someone who knows this better please fix it for nsec */ 1415 iap->ia_mtime.tv_sec = v_mtime; 1416 iap->ia_atime.tv_sec = v_atime; 1417 iap->ia_mtime.tv_nsec = 0; 1418 iap->ia_atime.tv_nsec = 0; 1419 } 1420 1421 set_attr: 1422 err = nfsd_create_setattr(rqstp, resfhp, iap); 1423 1424 /* 1425 * nfsd_setattr already committed the child (and possibly also the parent). 1426 */ 1427 if (!err) 1428 err = nfserrno(commit_metadata(fhp)); 1429 1430 /* 1431 * Update the filehandle to get the new inode info. 1432 */ 1433 if (!err) 1434 err = fh_update(resfhp); 1435 1436 out: 1437 fh_unlock(fhp); 1438 if (dchild && !IS_ERR(dchild)) 1439 dput(dchild); 1440 fh_drop_write(fhp); 1441 return err; 1442 1443 out_nfserr: 1444 err = nfserrno(host_err); 1445 goto out; 1446 } 1447 #endif /* CONFIG_NFSD_V3 */ 1448 1449 /* 1450 * Read a symlink. On entry, *lenp must contain the maximum path length that 1451 * fits into the buffer. On return, it contains the true length. 1452 * N.B. After this call fhp needs an fh_put 1453 */ 1454 __be32 1455 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1456 { 1457 struct inode *inode; 1458 mm_segment_t oldfs; 1459 __be32 err; 1460 int host_err; 1461 struct path path; 1462 1463 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); 1464 if (err) 1465 goto out; 1466 1467 path.mnt = fhp->fh_export->ex_path.mnt; 1468 path.dentry = fhp->fh_dentry; 1469 inode = path.dentry->d_inode; 1470 1471 err = nfserr_inval; 1472 if (!inode->i_op->readlink) 1473 goto out; 1474 1475 touch_atime(&path); 1476 /* N.B. Why does this call need a get_fs()?? 1477 * Remove the set_fs and watch the fireworks:-) --okir 1478 */ 1479 1480 oldfs = get_fs(); set_fs(KERNEL_DS); 1481 host_err = inode->i_op->readlink(path.dentry, (char __user *)buf, *lenp); 1482 set_fs(oldfs); 1483 1484 if (host_err < 0) 1485 goto out_nfserr; 1486 *lenp = host_err; 1487 err = 0; 1488 out: 1489 return err; 1490 1491 out_nfserr: 1492 err = nfserrno(host_err); 1493 goto out; 1494 } 1495 1496 /* 1497 * Create a symlink and look up its inode 1498 * N.B. After this call _both_ fhp and resfhp need an fh_put 1499 */ 1500 __be32 1501 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1502 char *fname, int flen, 1503 char *path, int plen, 1504 struct svc_fh *resfhp, 1505 struct iattr *iap) 1506 { 1507 struct dentry *dentry, *dnew; 1508 __be32 err, cerr; 1509 int host_err; 1510 1511 err = nfserr_noent; 1512 if (!flen || !plen) 1513 goto out; 1514 err = nfserr_exist; 1515 if (isdotent(fname, flen)) 1516 goto out; 1517 1518 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1519 if (err) 1520 goto out; 1521 1522 host_err = fh_want_write(fhp); 1523 if (host_err) 1524 goto out_nfserr; 1525 1526 fh_lock(fhp); 1527 dentry = fhp->fh_dentry; 1528 dnew = lookup_one_len(fname, dentry, flen); 1529 host_err = PTR_ERR(dnew); 1530 if (IS_ERR(dnew)) 1531 goto out_nfserr; 1532 1533 if (unlikely(path[plen] != 0)) { 1534 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1535 if (path_alloced == NULL) 1536 host_err = -ENOMEM; 1537 else { 1538 strncpy(path_alloced, path, plen); 1539 path_alloced[plen] = 0; 1540 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced); 1541 kfree(path_alloced); 1542 } 1543 } else 1544 host_err = vfs_symlink(dentry->d_inode, dnew, path); 1545 err = nfserrno(host_err); 1546 if (!err) 1547 err = nfserrno(commit_metadata(fhp)); 1548 fh_unlock(fhp); 1549 1550 fh_drop_write(fhp); 1551 1552 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1553 dput(dnew); 1554 if (err==0) err = cerr; 1555 out: 1556 return err; 1557 1558 out_nfserr: 1559 err = nfserrno(host_err); 1560 goto out; 1561 } 1562 1563 /* 1564 * Create a hardlink 1565 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1566 */ 1567 __be32 1568 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1569 char *name, int len, struct svc_fh *tfhp) 1570 { 1571 struct dentry *ddir, *dnew, *dold; 1572 struct inode *dirp; 1573 __be32 err; 1574 int host_err; 1575 1576 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); 1577 if (err) 1578 goto out; 1579 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP); 1580 if (err) 1581 goto out; 1582 err = nfserr_isdir; 1583 if (S_ISDIR(tfhp->fh_dentry->d_inode->i_mode)) 1584 goto out; 1585 err = nfserr_perm; 1586 if (!len) 1587 goto out; 1588 err = nfserr_exist; 1589 if (isdotent(name, len)) 1590 goto out; 1591 1592 host_err = fh_want_write(tfhp); 1593 if (host_err) { 1594 err = nfserrno(host_err); 1595 goto out; 1596 } 1597 1598 fh_lock_nested(ffhp, I_MUTEX_PARENT); 1599 ddir = ffhp->fh_dentry; 1600 dirp = ddir->d_inode; 1601 1602 dnew = lookup_one_len(name, ddir, len); 1603 host_err = PTR_ERR(dnew); 1604 if (IS_ERR(dnew)) 1605 goto out_nfserr; 1606 1607 dold = tfhp->fh_dentry; 1608 1609 err = nfserr_noent; 1610 if (!dold->d_inode) 1611 goto out_dput; 1612 host_err = nfsd_break_lease(dold->d_inode); 1613 if (host_err) { 1614 err = nfserrno(host_err); 1615 goto out_dput; 1616 } 1617 host_err = vfs_link(dold, dirp, dnew, NULL); 1618 if (!host_err) { 1619 err = nfserrno(commit_metadata(ffhp)); 1620 if (!err) 1621 err = nfserrno(commit_metadata(tfhp)); 1622 } else { 1623 if (host_err == -EXDEV && rqstp->rq_vers == 2) 1624 err = nfserr_acces; 1625 else 1626 err = nfserrno(host_err); 1627 } 1628 out_dput: 1629 dput(dnew); 1630 out_unlock: 1631 fh_unlock(ffhp); 1632 fh_drop_write(tfhp); 1633 out: 1634 return err; 1635 1636 out_nfserr: 1637 err = nfserrno(host_err); 1638 goto out_unlock; 1639 } 1640 1641 /* 1642 * Rename a file 1643 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1644 */ 1645 __be32 1646 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1647 struct svc_fh *tfhp, char *tname, int tlen) 1648 { 1649 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1650 struct inode *fdir, *tdir; 1651 __be32 err; 1652 int host_err; 1653 1654 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); 1655 if (err) 1656 goto out; 1657 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE); 1658 if (err) 1659 goto out; 1660 1661 fdentry = ffhp->fh_dentry; 1662 fdir = fdentry->d_inode; 1663 1664 tdentry = tfhp->fh_dentry; 1665 tdir = tdentry->d_inode; 1666 1667 err = nfserr_perm; 1668 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1669 goto out; 1670 1671 host_err = fh_want_write(ffhp); 1672 if (host_err) { 1673 err = nfserrno(host_err); 1674 goto out; 1675 } 1676 1677 /* cannot use fh_lock as we need deadlock protective ordering 1678 * so do it by hand */ 1679 trap = lock_rename(tdentry, fdentry); 1680 ffhp->fh_locked = tfhp->fh_locked = 1; 1681 fill_pre_wcc(ffhp); 1682 fill_pre_wcc(tfhp); 1683 1684 odentry = lookup_one_len(fname, fdentry, flen); 1685 host_err = PTR_ERR(odentry); 1686 if (IS_ERR(odentry)) 1687 goto out_nfserr; 1688 1689 host_err = -ENOENT; 1690 if (!odentry->d_inode) 1691 goto out_dput_old; 1692 host_err = -EINVAL; 1693 if (odentry == trap) 1694 goto out_dput_old; 1695 1696 ndentry = lookup_one_len(tname, tdentry, tlen); 1697 host_err = PTR_ERR(ndentry); 1698 if (IS_ERR(ndentry)) 1699 goto out_dput_old; 1700 host_err = -ENOTEMPTY; 1701 if (ndentry == trap) 1702 goto out_dput_new; 1703 1704 host_err = -EXDEV; 1705 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) 1706 goto out_dput_new; 1707 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry) 1708 goto out_dput_new; 1709 1710 host_err = nfsd_break_lease(odentry->d_inode); 1711 if (host_err) 1712 goto out_dput_new; 1713 if (ndentry->d_inode) { 1714 host_err = nfsd_break_lease(ndentry->d_inode); 1715 if (host_err) 1716 goto out_dput_new; 1717 } 1718 host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL); 1719 if (!host_err) { 1720 host_err = commit_metadata(tfhp); 1721 if (!host_err) 1722 host_err = commit_metadata(ffhp); 1723 } 1724 out_dput_new: 1725 dput(ndentry); 1726 out_dput_old: 1727 dput(odentry); 1728 out_nfserr: 1729 err = nfserrno(host_err); 1730 1731 /* we cannot reply on fh_unlock on the two filehandles, 1732 * as that would do the wrong thing if the two directories 1733 * were the same, so again we do it by hand 1734 */ 1735 fill_post_wcc(ffhp); 1736 fill_post_wcc(tfhp); 1737 unlock_rename(tdentry, fdentry); 1738 ffhp->fh_locked = tfhp->fh_locked = 0; 1739 fh_drop_write(ffhp); 1740 1741 out: 1742 return err; 1743 } 1744 1745 /* 1746 * Unlink a file or directory 1747 * N.B. After this call fhp needs an fh_put 1748 */ 1749 __be32 1750 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1751 char *fname, int flen) 1752 { 1753 struct dentry *dentry, *rdentry; 1754 struct inode *dirp; 1755 __be32 err; 1756 int host_err; 1757 1758 err = nfserr_acces; 1759 if (!flen || isdotent(fname, flen)) 1760 goto out; 1761 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); 1762 if (err) 1763 goto out; 1764 1765 host_err = fh_want_write(fhp); 1766 if (host_err) 1767 goto out_nfserr; 1768 1769 fh_lock_nested(fhp, I_MUTEX_PARENT); 1770 dentry = fhp->fh_dentry; 1771 dirp = dentry->d_inode; 1772 1773 rdentry = lookup_one_len(fname, dentry, flen); 1774 host_err = PTR_ERR(rdentry); 1775 if (IS_ERR(rdentry)) 1776 goto out_nfserr; 1777 1778 if (!rdentry->d_inode) { 1779 dput(rdentry); 1780 err = nfserr_noent; 1781 goto out; 1782 } 1783 1784 if (!type) 1785 type = rdentry->d_inode->i_mode & S_IFMT; 1786 1787 host_err = nfsd_break_lease(rdentry->d_inode); 1788 if (host_err) 1789 goto out_put; 1790 if (type != S_IFDIR) 1791 host_err = vfs_unlink(dirp, rdentry, NULL); 1792 else 1793 host_err = vfs_rmdir(dirp, rdentry); 1794 if (!host_err) 1795 host_err = commit_metadata(fhp); 1796 out_put: 1797 dput(rdentry); 1798 1799 out_nfserr: 1800 err = nfserrno(host_err); 1801 out: 1802 return err; 1803 } 1804 1805 /* 1806 * We do this buffering because we must not call back into the file 1807 * system's ->lookup() method from the filldir callback. That may well 1808 * deadlock a number of file systems. 1809 * 1810 * This is based heavily on the implementation of same in XFS. 1811 */ 1812 struct buffered_dirent { 1813 u64 ino; 1814 loff_t offset; 1815 int namlen; 1816 unsigned int d_type; 1817 char name[]; 1818 }; 1819 1820 struct readdir_data { 1821 struct dir_context ctx; 1822 char *dirent; 1823 size_t used; 1824 int full; 1825 }; 1826 1827 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, 1828 loff_t offset, u64 ino, unsigned int d_type) 1829 { 1830 struct readdir_data *buf = __buf; 1831 struct buffered_dirent *de = (void *)(buf->dirent + buf->used); 1832 unsigned int reclen; 1833 1834 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); 1835 if (buf->used + reclen > PAGE_SIZE) { 1836 buf->full = 1; 1837 return -EINVAL; 1838 } 1839 1840 de->namlen = namlen; 1841 de->offset = offset; 1842 de->ino = ino; 1843 de->d_type = d_type; 1844 memcpy(de->name, name, namlen); 1845 buf->used += reclen; 1846 1847 return 0; 1848 } 1849 1850 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, 1851 struct readdir_cd *cdp, loff_t *offsetp) 1852 { 1853 struct buffered_dirent *de; 1854 int host_err; 1855 int size; 1856 loff_t offset; 1857 struct readdir_data buf = { 1858 .ctx.actor = nfsd_buffered_filldir, 1859 .dirent = (void *)__get_free_page(GFP_KERNEL) 1860 }; 1861 1862 if (!buf.dirent) 1863 return nfserrno(-ENOMEM); 1864 1865 offset = *offsetp; 1866 1867 while (1) { 1868 struct inode *dir_inode = file_inode(file); 1869 unsigned int reclen; 1870 1871 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1872 buf.used = 0; 1873 buf.full = 0; 1874 1875 host_err = iterate_dir(file, &buf.ctx); 1876 if (buf.full) 1877 host_err = 0; 1878 1879 if (host_err < 0) 1880 break; 1881 1882 size = buf.used; 1883 1884 if (!size) 1885 break; 1886 1887 /* 1888 * Various filldir functions may end up calling back into 1889 * lookup_one_len() and the file system's ->lookup() method. 1890 * These expect i_mutex to be held, as it would within readdir. 1891 */ 1892 host_err = mutex_lock_killable(&dir_inode->i_mutex); 1893 if (host_err) 1894 break; 1895 1896 de = (struct buffered_dirent *)buf.dirent; 1897 while (size > 0) { 1898 offset = de->offset; 1899 1900 if (func(cdp, de->name, de->namlen, de->offset, 1901 de->ino, de->d_type)) 1902 break; 1903 1904 if (cdp->err != nfs_ok) 1905 break; 1906 1907 reclen = ALIGN(sizeof(*de) + de->namlen, 1908 sizeof(u64)); 1909 size -= reclen; 1910 de = (struct buffered_dirent *)((char *)de + reclen); 1911 } 1912 mutex_unlock(&dir_inode->i_mutex); 1913 if (size > 0) /* We bailed out early */ 1914 break; 1915 1916 offset = vfs_llseek(file, 0, SEEK_CUR); 1917 } 1918 1919 free_page((unsigned long)(buf.dirent)); 1920 1921 if (host_err) 1922 return nfserrno(host_err); 1923 1924 *offsetp = offset; 1925 return cdp->err; 1926 } 1927 1928 /* 1929 * Read entries from a directory. 1930 * The NFSv3/4 verifier we ignore for now. 1931 */ 1932 __be32 1933 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 1934 struct readdir_cd *cdp, filldir_t func) 1935 { 1936 __be32 err; 1937 struct file *file; 1938 loff_t offset = *offsetp; 1939 int may_flags = NFSD_MAY_READ; 1940 1941 /* NFSv2 only supports 32 bit cookies */ 1942 if (rqstp->rq_vers > 2) 1943 may_flags |= NFSD_MAY_64BIT_COOKIE; 1944 1945 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file); 1946 if (err) 1947 goto out; 1948 1949 offset = vfs_llseek(file, offset, SEEK_SET); 1950 if (offset < 0) { 1951 err = nfserrno((int)offset); 1952 goto out_close; 1953 } 1954 1955 err = nfsd_buffered_readdir(file, func, cdp, offsetp); 1956 1957 if (err == nfserr_eof || err == nfserr_toosmall) 1958 err = nfs_ok; /* can still be found in ->err */ 1959 out_close: 1960 nfsd_close(file); 1961 out: 1962 return err; 1963 } 1964 1965 /* 1966 * Get file system stats 1967 * N.B. After this call fhp needs an fh_put 1968 */ 1969 __be32 1970 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) 1971 { 1972 __be32 err; 1973 1974 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); 1975 if (!err) { 1976 struct path path = { 1977 .mnt = fhp->fh_export->ex_path.mnt, 1978 .dentry = fhp->fh_dentry, 1979 }; 1980 if (vfs_statfs(&path, stat)) 1981 err = nfserr_io; 1982 } 1983 return err; 1984 } 1985 1986 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) 1987 { 1988 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; 1989 } 1990 1991 /* 1992 * Check for a user's access permissions to this inode. 1993 */ 1994 __be32 1995 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, 1996 struct dentry *dentry, int acc) 1997 { 1998 struct inode *inode = dentry->d_inode; 1999 int err; 2000 2001 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP) 2002 return 0; 2003 #if 0 2004 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 2005 acc, 2006 (acc & NFSD_MAY_READ)? " read" : "", 2007 (acc & NFSD_MAY_WRITE)? " write" : "", 2008 (acc & NFSD_MAY_EXEC)? " exec" : "", 2009 (acc & NFSD_MAY_SATTR)? " sattr" : "", 2010 (acc & NFSD_MAY_TRUNC)? " trunc" : "", 2011 (acc & NFSD_MAY_LOCK)? " lock" : "", 2012 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", 2013 inode->i_mode, 2014 IS_IMMUTABLE(inode)? " immut" : "", 2015 IS_APPEND(inode)? " append" : "", 2016 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); 2017 dprintk(" owner %d/%d user %d/%d\n", 2018 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); 2019 #endif 2020 2021 /* Normally we reject any write/sattr etc access on a read-only file 2022 * system. But if it is IRIX doing check on write-access for a 2023 * device special file, we ignore rofs. 2024 */ 2025 if (!(acc & NFSD_MAY_LOCAL_ACCESS)) 2026 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { 2027 if (exp_rdonly(rqstp, exp) || 2028 __mnt_is_readonly(exp->ex_path.mnt)) 2029 return nfserr_rofs; 2030 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) 2031 return nfserr_perm; 2032 } 2033 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) 2034 return nfserr_perm; 2035 2036 if (acc & NFSD_MAY_LOCK) { 2037 /* If we cannot rely on authentication in NLM requests, 2038 * just allow locks, otherwise require read permission, or 2039 * ownership 2040 */ 2041 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 2042 return 0; 2043 else 2044 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE; 2045 } 2046 /* 2047 * The file owner always gets access permission for accesses that 2048 * would normally be checked at open time. This is to make 2049 * file access work even when the client has done a fchmod(fd, 0). 2050 * 2051 * However, `cp foo bar' should fail nevertheless when bar is 2052 * readonly. A sensible way to do this might be to reject all 2053 * attempts to truncate a read-only file, because a creat() call 2054 * always implies file truncation. 2055 * ... but this isn't really fair. A process may reasonably call 2056 * ftruncate on an open file descriptor on a file with perm 000. 2057 * We must trust the client to do permission checking - using "ACCESS" 2058 * with NFSv3. 2059 */ 2060 if ((acc & NFSD_MAY_OWNER_OVERRIDE) && 2061 uid_eq(inode->i_uid, current_fsuid())) 2062 return 0; 2063 2064 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ 2065 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); 2066 2067 /* Allow read access to binaries even when mode 111 */ 2068 if (err == -EACCES && S_ISREG(inode->i_mode) && 2069 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) || 2070 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC))) 2071 err = inode_permission(inode, MAY_EXEC); 2072 2073 return err? nfserrno(err) : 0; 2074 } 2075 2076 void 2077 nfsd_racache_shutdown(void) 2078 { 2079 struct raparms *raparm, *last_raparm; 2080 unsigned int i; 2081 2082 dprintk("nfsd: freeing readahead buffers.\n"); 2083 2084 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2085 raparm = raparm_hash[i].pb_head; 2086 while(raparm) { 2087 last_raparm = raparm; 2088 raparm = raparm->p_next; 2089 kfree(last_raparm); 2090 } 2091 raparm_hash[i].pb_head = NULL; 2092 } 2093 } 2094 /* 2095 * Initialize readahead param cache 2096 */ 2097 int 2098 nfsd_racache_init(int cache_size) 2099 { 2100 int i; 2101 int j = 0; 2102 int nperbucket; 2103 struct raparms **raparm = NULL; 2104 2105 2106 if (raparm_hash[0].pb_head) 2107 return 0; 2108 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE); 2109 if (nperbucket < 2) 2110 nperbucket = 2; 2111 cache_size = nperbucket * RAPARM_HASH_SIZE; 2112 2113 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); 2114 2115 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2116 spin_lock_init(&raparm_hash[i].pb_lock); 2117 2118 raparm = &raparm_hash[i].pb_head; 2119 for (j = 0; j < nperbucket; j++) { 2120 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL); 2121 if (!*raparm) 2122 goto out_nomem; 2123 raparm = &(*raparm)->p_next; 2124 } 2125 *raparm = NULL; 2126 } 2127 2128 nfsdstats.ra_size = cache_size; 2129 return 0; 2130 2131 out_nomem: 2132 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n"); 2133 nfsd_racache_shutdown(); 2134 return -ENOMEM; 2135 } 2136