1 #define MSNFS /* HACK HACK */ 2 /* 3 * File operations used by nfsd. Some of these have been ripped from 4 * other parts of the kernel because they weren't exported, others 5 * are partial duplicates with added or changed functionality. 6 * 7 * Note that several functions dget() the dentry upon which they want 8 * to act, most notably those that create directory entries. Response 9 * dentry's are dput()'d if necessary in the release callback. 10 * So if you notice code paths that apparently fail to dput() the 11 * dentry, don't worry--they have been taken care of. 12 * 13 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de> 14 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp> 15 */ 16 17 #include <linux/fs.h> 18 #include <linux/file.h> 19 #include <linux/splice.h> 20 #include <linux/fcntl.h> 21 #include <linux/namei.h> 22 #include <linux/delay.h> 23 #include <linux/fsnotify.h> 24 #include <linux/posix_acl_xattr.h> 25 #include <linux/xattr.h> 26 #include <linux/jhash.h> 27 #include <linux/ima.h> 28 #include <linux/slab.h> 29 #include <asm/uaccess.h> 30 #include <linux/exportfs.h> 31 #include <linux/writeback.h> 32 33 #ifdef CONFIG_NFSD_V3 34 #include "xdr3.h" 35 #endif /* CONFIG_NFSD_V3 */ 36 37 #ifdef CONFIG_NFSD_V4 38 #include <linux/nfs4_acl.h> 39 #include <linux/nfsd_idmap.h> 40 #endif /* CONFIG_NFSD_V4 */ 41 42 #include "nfsd.h" 43 #include "vfs.h" 44 45 #define NFSDDBG_FACILITY NFSDDBG_FILEOP 46 47 48 /* 49 * This is a cache of readahead params that help us choose the proper 50 * readahead strategy. Initially, we set all readahead parameters to 0 51 * and let the VFS handle things. 52 * If you increase the number of cached files very much, you'll need to 53 * add a hash table here. 54 */ 55 struct raparms { 56 struct raparms *p_next; 57 unsigned int p_count; 58 ino_t p_ino; 59 dev_t p_dev; 60 int p_set; 61 struct file_ra_state p_ra; 62 unsigned int p_hindex; 63 }; 64 65 struct raparm_hbucket { 66 struct raparms *pb_head; 67 spinlock_t pb_lock; 68 } ____cacheline_aligned_in_smp; 69 70 #define RAPARM_HASH_BITS 4 71 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS) 72 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1) 73 static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE]; 74 75 /* 76 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 77 * a mount point. 78 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged, 79 * or nfs_ok having possibly changed *dpp and *expp 80 */ 81 int 82 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 83 struct svc_export **expp) 84 { 85 struct svc_export *exp = *expp, *exp2 = NULL; 86 struct dentry *dentry = *dpp; 87 struct path path = {.mnt = mntget(exp->ex_path.mnt), 88 .dentry = dget(dentry)}; 89 int err = 0; 90 91 while (d_mountpoint(path.dentry) && follow_down(&path)) 92 ; 93 94 exp2 = rqst_exp_get_by_name(rqstp, &path); 95 if (IS_ERR(exp2)) { 96 err = PTR_ERR(exp2); 97 /* 98 * We normally allow NFS clients to continue 99 * "underneath" a mountpoint that is not exported. 100 * The exception is V4ROOT, where no traversal is ever 101 * allowed without an explicit export of the new 102 * directory. 103 */ 104 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT)) 105 err = 0; 106 path_put(&path); 107 goto out; 108 } 109 if (nfsd_v4client(rqstp) || 110 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) { 111 /* successfully crossed mount point */ 112 /* 113 * This is subtle: path.dentry is *not* on path.mnt 114 * at this point. The only reason we are safe is that 115 * original mnt is pinned down by exp, so we should 116 * put path *before* putting exp 117 */ 118 *dpp = path.dentry; 119 path.dentry = dentry; 120 *expp = exp2; 121 exp2 = exp; 122 } 123 path_put(&path); 124 exp_put(exp2); 125 out: 126 return err; 127 } 128 129 static void follow_to_parent(struct path *path) 130 { 131 struct dentry *dp; 132 133 while (path->dentry == path->mnt->mnt_root && follow_up(path)) 134 ; 135 dp = dget_parent(path->dentry); 136 dput(path->dentry); 137 path->dentry = dp; 138 } 139 140 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp) 141 { 142 struct svc_export *exp2; 143 struct path path = {.mnt = mntget((*exp)->ex_path.mnt), 144 .dentry = dget(dparent)}; 145 146 follow_to_parent(&path); 147 148 exp2 = rqst_exp_parent(rqstp, &path); 149 if (PTR_ERR(exp2) == -ENOENT) { 150 *dentryp = dget(dparent); 151 } else if (IS_ERR(exp2)) { 152 path_put(&path); 153 return PTR_ERR(exp2); 154 } else { 155 *dentryp = dget(path.dentry); 156 exp_put(*exp); 157 *exp = exp2; 158 } 159 path_put(&path); 160 return 0; 161 } 162 163 /* 164 * For nfsd purposes, we treat V4ROOT exports as though there was an 165 * export at *every* directory. 166 */ 167 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) 168 { 169 if (d_mountpoint(dentry)) 170 return 1; 171 if (!(exp->ex_flags & NFSEXP_V4ROOT)) 172 return 0; 173 return dentry->d_inode != NULL; 174 } 175 176 __be32 177 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, 178 const char *name, unsigned int len, 179 struct svc_export **exp_ret, struct dentry **dentry_ret) 180 { 181 struct svc_export *exp; 182 struct dentry *dparent; 183 struct dentry *dentry; 184 __be32 err; 185 int host_err; 186 187 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); 188 189 /* Obtain dentry and export. */ 190 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); 191 if (err) 192 return err; 193 194 dparent = fhp->fh_dentry; 195 exp = fhp->fh_export; 196 exp_get(exp); 197 198 /* Lookup the name, but don't follow links */ 199 if (isdotent(name, len)) { 200 if (len==1) 201 dentry = dget(dparent); 202 else if (dparent != exp->ex_path.dentry) 203 dentry = dget_parent(dparent); 204 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp)) 205 dentry = dget(dparent); /* .. == . just like at / */ 206 else { 207 /* checking mountpoint crossing is very different when stepping up */ 208 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry); 209 if (host_err) 210 goto out_nfserr; 211 } 212 } else { 213 fh_lock(fhp); 214 dentry = lookup_one_len(name, dparent, len); 215 host_err = PTR_ERR(dentry); 216 if (IS_ERR(dentry)) 217 goto out_nfserr; 218 /* 219 * check if we have crossed a mount point ... 220 */ 221 if (nfsd_mountpoint(dentry, exp)) { 222 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) { 223 dput(dentry); 224 goto out_nfserr; 225 } 226 } 227 } 228 *dentry_ret = dentry; 229 *exp_ret = exp; 230 return 0; 231 232 out_nfserr: 233 exp_put(exp); 234 return nfserrno(host_err); 235 } 236 237 /* 238 * Look up one component of a pathname. 239 * N.B. After this call _both_ fhp and resfh need an fh_put 240 * 241 * If the lookup would cross a mountpoint, and the mounted filesystem 242 * is exported to the client with NFSEXP_NOHIDE, then the lookup is 243 * accepted as it stands and the mounted directory is 244 * returned. Otherwise the covered directory is returned. 245 * NOTE: this mountpoint crossing is not supported properly by all 246 * clients and is explicitly disallowed for NFSv3 247 * NeilBrown <neilb@cse.unsw.edu.au> 248 */ 249 __be32 250 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, 251 unsigned int len, struct svc_fh *resfh) 252 { 253 struct svc_export *exp; 254 struct dentry *dentry; 255 __be32 err; 256 257 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry); 258 if (err) 259 return err; 260 err = check_nfsd_access(exp, rqstp); 261 if (err) 262 goto out; 263 /* 264 * Note: we compose the file handle now, but as the 265 * dentry may be negative, it may need to be updated. 266 */ 267 err = fh_compose(resfh, exp, dentry, fhp); 268 if (!err && !dentry->d_inode) 269 err = nfserr_noent; 270 out: 271 dput(dentry); 272 exp_put(exp); 273 return err; 274 } 275 276 /* 277 * Commit metadata changes to stable storage. 278 */ 279 static int 280 commit_metadata(struct svc_fh *fhp) 281 { 282 struct inode *inode = fhp->fh_dentry->d_inode; 283 const struct export_operations *export_ops = inode->i_sb->s_export_op; 284 int error = 0; 285 286 if (!EX_ISSYNC(fhp->fh_export)) 287 return 0; 288 289 if (export_ops->commit_metadata) { 290 error = export_ops->commit_metadata(inode); 291 } else { 292 struct writeback_control wbc = { 293 .sync_mode = WB_SYNC_ALL, 294 .nr_to_write = 0, /* metadata only */ 295 }; 296 297 error = sync_inode(inode, &wbc); 298 } 299 300 return error; 301 } 302 303 /* 304 * Set various file attributes. 305 * N.B. After this call fhp needs an fh_put 306 */ 307 __be32 308 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 309 int check_guard, time_t guardtime) 310 { 311 struct dentry *dentry; 312 struct inode *inode; 313 int accmode = NFSD_MAY_SATTR; 314 int ftype = 0; 315 __be32 err; 316 int host_err; 317 int size_change = 0; 318 319 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 320 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; 321 if (iap->ia_valid & ATTR_SIZE) 322 ftype = S_IFREG; 323 324 /* Get inode */ 325 err = fh_verify(rqstp, fhp, ftype, accmode); 326 if (err) 327 goto out; 328 329 dentry = fhp->fh_dentry; 330 inode = dentry->d_inode; 331 332 /* Ignore any mode updates on symlinks */ 333 if (S_ISLNK(inode->i_mode)) 334 iap->ia_valid &= ~ATTR_MODE; 335 336 if (!iap->ia_valid) 337 goto out; 338 339 /* 340 * NFSv2 does not differentiate between "set-[ac]time-to-now" 341 * which only requires access, and "set-[ac]time-to-X" which 342 * requires ownership. 343 * So if it looks like it might be "set both to the same time which 344 * is close to now", and if inode_change_ok fails, then we 345 * convert to "set to now" instead of "set to explicit time" 346 * 347 * We only call inode_change_ok as the last test as technically 348 * it is not an interface that we should be using. It is only 349 * valid if the filesystem does not define it's own i_op->setattr. 350 */ 351 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 352 #define MAX_TOUCH_TIME_ERROR (30*60) 353 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && 354 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) { 355 /* 356 * Looks probable. 357 * 358 * Now just make sure time is in the right ballpark. 359 * Solaris, at least, doesn't seem to care what the time 360 * request is. We require it be within 30 minutes of now. 361 */ 362 time_t delta = iap->ia_atime.tv_sec - get_seconds(); 363 if (delta < 0) 364 delta = -delta; 365 if (delta < MAX_TOUCH_TIME_ERROR && 366 inode_change_ok(inode, iap) != 0) { 367 /* 368 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME. 369 * This will cause notify_change to set these times 370 * to "now" 371 */ 372 iap->ia_valid &= ~BOTH_TIME_SET; 373 } 374 } 375 376 /* 377 * The size case is special. 378 * It changes the file as well as the attributes. 379 */ 380 if (iap->ia_valid & ATTR_SIZE) { 381 if (iap->ia_size < inode->i_size) { 382 err = nfsd_permission(rqstp, fhp->fh_export, dentry, 383 NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE); 384 if (err) 385 goto out; 386 } 387 388 /* 389 * If we are changing the size of the file, then 390 * we need to break all leases. 391 */ 392 host_err = break_lease(inode, O_WRONLY | O_NONBLOCK); 393 if (host_err == -EWOULDBLOCK) 394 host_err = -ETIMEDOUT; 395 if (host_err) /* ENOMEM or EWOULDBLOCK */ 396 goto out_nfserr; 397 398 host_err = get_write_access(inode); 399 if (host_err) 400 goto out_nfserr; 401 402 size_change = 1; 403 host_err = locks_verify_truncate(inode, NULL, iap->ia_size); 404 if (host_err) { 405 put_write_access(inode); 406 goto out_nfserr; 407 } 408 } 409 410 /* sanitize the mode change */ 411 if (iap->ia_valid & ATTR_MODE) { 412 iap->ia_mode &= S_IALLUGO; 413 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); 414 } 415 416 /* Revoke setuid/setgid on chown */ 417 if (!S_ISDIR(inode->i_mode) && 418 (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) || 419 ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) { 420 iap->ia_valid |= ATTR_KILL_PRIV; 421 if (iap->ia_valid & ATTR_MODE) { 422 /* we're setting mode too, just clear the s*id bits */ 423 iap->ia_mode &= ~S_ISUID; 424 if (iap->ia_mode & S_IXGRP) 425 iap->ia_mode &= ~S_ISGID; 426 } else { 427 /* set ATTR_KILL_* bits and let VFS handle it */ 428 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID); 429 } 430 } 431 432 /* Change the attributes. */ 433 434 iap->ia_valid |= ATTR_CTIME; 435 436 err = nfserr_notsync; 437 if (!check_guard || guardtime == inode->i_ctime.tv_sec) { 438 fh_lock(fhp); 439 host_err = notify_change(dentry, iap); 440 err = nfserrno(host_err); 441 fh_unlock(fhp); 442 } 443 if (size_change) 444 put_write_access(inode); 445 if (!err) 446 if (EX_ISSYNC(fhp->fh_export)) 447 write_inode_now(inode, 1); 448 out: 449 return err; 450 451 out_nfserr: 452 err = nfserrno(host_err); 453 goto out; 454 } 455 456 #if defined(CONFIG_NFSD_V2_ACL) || \ 457 defined(CONFIG_NFSD_V3_ACL) || \ 458 defined(CONFIG_NFSD_V4) 459 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf) 460 { 461 ssize_t buflen; 462 ssize_t ret; 463 464 buflen = vfs_getxattr(dentry, key, NULL, 0); 465 if (buflen <= 0) 466 return buflen; 467 468 *buf = kmalloc(buflen, GFP_KERNEL); 469 if (!*buf) 470 return -ENOMEM; 471 472 ret = vfs_getxattr(dentry, key, *buf, buflen); 473 if (ret < 0) 474 kfree(*buf); 475 return ret; 476 } 477 #endif 478 479 #if defined(CONFIG_NFSD_V4) 480 static int 481 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key) 482 { 483 int len; 484 size_t buflen; 485 char *buf = NULL; 486 int error = 0; 487 488 buflen = posix_acl_xattr_size(pacl->a_count); 489 buf = kmalloc(buflen, GFP_KERNEL); 490 error = -ENOMEM; 491 if (buf == NULL) 492 goto out; 493 494 len = posix_acl_to_xattr(pacl, buf, buflen); 495 if (len < 0) { 496 error = len; 497 goto out; 498 } 499 500 error = vfs_setxattr(dentry, key, buf, len, 0); 501 out: 502 kfree(buf); 503 return error; 504 } 505 506 __be32 507 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 508 struct nfs4_acl *acl) 509 { 510 __be32 error; 511 int host_error; 512 struct dentry *dentry; 513 struct inode *inode; 514 struct posix_acl *pacl = NULL, *dpacl = NULL; 515 unsigned int flags = 0; 516 517 /* Get inode */ 518 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); 519 if (error) 520 return error; 521 522 dentry = fhp->fh_dentry; 523 inode = dentry->d_inode; 524 if (S_ISDIR(inode->i_mode)) 525 flags = NFS4_ACL_DIR; 526 527 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 528 if (host_error == -EINVAL) { 529 return nfserr_attrnotsupp; 530 } else if (host_error < 0) 531 goto out_nfserr; 532 533 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); 534 if (host_error < 0) 535 goto out_release; 536 537 if (S_ISDIR(inode->i_mode)) 538 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); 539 540 out_release: 541 posix_acl_release(pacl); 542 posix_acl_release(dpacl); 543 out_nfserr: 544 if (host_error == -EOPNOTSUPP) 545 return nfserr_attrnotsupp; 546 else 547 return nfserrno(host_error); 548 } 549 550 static struct posix_acl * 551 _get_posix_acl(struct dentry *dentry, char *key) 552 { 553 void *buf = NULL; 554 struct posix_acl *pacl = NULL; 555 int buflen; 556 557 buflen = nfsd_getxattr(dentry, key, &buf); 558 if (!buflen) 559 buflen = -ENODATA; 560 if (buflen <= 0) 561 return ERR_PTR(buflen); 562 563 pacl = posix_acl_from_xattr(buf, buflen); 564 kfree(buf); 565 return pacl; 566 } 567 568 int 569 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl) 570 { 571 struct inode *inode = dentry->d_inode; 572 int error = 0; 573 struct posix_acl *pacl = NULL, *dpacl = NULL; 574 unsigned int flags = 0; 575 576 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS); 577 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA) 578 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 579 if (IS_ERR(pacl)) { 580 error = PTR_ERR(pacl); 581 pacl = NULL; 582 goto out; 583 } 584 585 if (S_ISDIR(inode->i_mode)) { 586 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT); 587 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA) 588 dpacl = NULL; 589 else if (IS_ERR(dpacl)) { 590 error = PTR_ERR(dpacl); 591 dpacl = NULL; 592 goto out; 593 } 594 flags = NFS4_ACL_DIR; 595 } 596 597 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags); 598 if (IS_ERR(*acl)) { 599 error = PTR_ERR(*acl); 600 *acl = NULL; 601 } 602 out: 603 posix_acl_release(pacl); 604 posix_acl_release(dpacl); 605 return error; 606 } 607 608 #endif /* defined(CONFIG_NFS_V4) */ 609 610 #ifdef CONFIG_NFSD_V3 611 /* 612 * Check server access rights to a file system object 613 */ 614 struct accessmap { 615 u32 access; 616 int how; 617 }; 618 static struct accessmap nfs3_regaccess[] = { 619 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 620 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 621 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, 622 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, 623 624 { 0, 0 } 625 }; 626 627 static struct accessmap nfs3_diraccess[] = { 628 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 629 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, 630 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, 631 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, 632 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, 633 634 { 0, 0 } 635 }; 636 637 static struct accessmap nfs3_anyaccess[] = { 638 /* Some clients - Solaris 2.6 at least, make an access call 639 * to the server to check for access for things like /dev/null 640 * (which really, the server doesn't care about). So 641 * We provide simple access checking for them, looking 642 * mainly at mode bits, and we make sure to ignore read-only 643 * filesystem checks 644 */ 645 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 646 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 647 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 648 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 649 650 { 0, 0 } 651 }; 652 653 __be32 654 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 655 { 656 struct accessmap *map; 657 struct svc_export *export; 658 struct dentry *dentry; 659 u32 query, result = 0, sresult = 0; 660 __be32 error; 661 662 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP); 663 if (error) 664 goto out; 665 666 export = fhp->fh_export; 667 dentry = fhp->fh_dentry; 668 669 if (S_ISREG(dentry->d_inode->i_mode)) 670 map = nfs3_regaccess; 671 else if (S_ISDIR(dentry->d_inode->i_mode)) 672 map = nfs3_diraccess; 673 else 674 map = nfs3_anyaccess; 675 676 677 query = *access; 678 for (; map->access; map++) { 679 if (map->access & query) { 680 __be32 err2; 681 682 sresult |= map->access; 683 684 err2 = nfsd_permission(rqstp, export, dentry, map->how); 685 switch (err2) { 686 case nfs_ok: 687 result |= map->access; 688 break; 689 690 /* the following error codes just mean the access was not allowed, 691 * rather than an error occurred */ 692 case nfserr_rofs: 693 case nfserr_acces: 694 case nfserr_perm: 695 /* simply don't "or" in the access bit. */ 696 break; 697 default: 698 error = err2; 699 goto out; 700 } 701 } 702 } 703 *access = result; 704 if (supported) 705 *supported = sresult; 706 707 out: 708 return error; 709 } 710 #endif /* CONFIG_NFSD_V3 */ 711 712 713 714 /* 715 * Open an existing file or directory. 716 * The access argument indicates the type of open (read/write/lock) 717 * N.B. After this call fhp needs an fh_put 718 */ 719 __be32 720 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 721 int access, struct file **filp) 722 { 723 struct dentry *dentry; 724 struct inode *inode; 725 int flags = O_RDONLY|O_LARGEFILE; 726 __be32 err; 727 int host_err; 728 729 validate_process_creds(); 730 731 /* 732 * If we get here, then the client has already done an "open", 733 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 734 * in case a chmod has now revoked permission. 735 */ 736 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE); 737 if (err) 738 goto out; 739 740 dentry = fhp->fh_dentry; 741 inode = dentry->d_inode; 742 743 /* Disallow write access to files with the append-only bit set 744 * or any access when mandatory locking enabled 745 */ 746 err = nfserr_perm; 747 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE)) 748 goto out; 749 /* 750 * We must ignore files (but only files) which might have mandatory 751 * locks on them because there is no way to know if the accesser has 752 * the lock. 753 */ 754 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode)) 755 goto out; 756 757 if (!inode->i_fop) 758 goto out; 759 760 /* 761 * Check to see if there are any leases on this file. 762 * This may block while leases are broken. 763 */ 764 host_err = break_lease(inode, O_NONBLOCK | ((access & NFSD_MAY_WRITE) ? O_WRONLY : 0)); 765 if (host_err == -EWOULDBLOCK) 766 host_err = -ETIMEDOUT; 767 if (host_err) /* NOMEM or WOULDBLOCK */ 768 goto out_nfserr; 769 770 if (access & NFSD_MAY_WRITE) { 771 if (access & NFSD_MAY_READ) 772 flags = O_RDWR|O_LARGEFILE; 773 else 774 flags = O_WRONLY|O_LARGEFILE; 775 } 776 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt), 777 flags, current_cred()); 778 if (IS_ERR(*filp)) 779 host_err = PTR_ERR(*filp); 780 else 781 host_err = ima_file_check(*filp, access); 782 out_nfserr: 783 err = nfserrno(host_err); 784 out: 785 validate_process_creds(); 786 return err; 787 } 788 789 /* 790 * Close a file. 791 */ 792 void 793 nfsd_close(struct file *filp) 794 { 795 fput(filp); 796 } 797 798 /* 799 * Obtain the readahead parameters for the file 800 * specified by (dev, ino). 801 */ 802 803 static inline struct raparms * 804 nfsd_get_raparms(dev_t dev, ino_t ino) 805 { 806 struct raparms *ra, **rap, **frap = NULL; 807 int depth = 0; 808 unsigned int hash; 809 struct raparm_hbucket *rab; 810 811 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK; 812 rab = &raparm_hash[hash]; 813 814 spin_lock(&rab->pb_lock); 815 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) { 816 if (ra->p_ino == ino && ra->p_dev == dev) 817 goto found; 818 depth++; 819 if (ra->p_count == 0) 820 frap = rap; 821 } 822 depth = nfsdstats.ra_size*11/10; 823 if (!frap) { 824 spin_unlock(&rab->pb_lock); 825 return NULL; 826 } 827 rap = frap; 828 ra = *frap; 829 ra->p_dev = dev; 830 ra->p_ino = ino; 831 ra->p_set = 0; 832 ra->p_hindex = hash; 833 found: 834 if (rap != &rab->pb_head) { 835 *rap = ra->p_next; 836 ra->p_next = rab->pb_head; 837 rab->pb_head = ra; 838 } 839 ra->p_count++; 840 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 841 spin_unlock(&rab->pb_lock); 842 return ra; 843 } 844 845 /* 846 * Grab and keep cached pages associated with a file in the svc_rqst 847 * so that they can be passed to the network sendmsg/sendpage routines 848 * directly. They will be released after the sending has completed. 849 */ 850 static int 851 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 852 struct splice_desc *sd) 853 { 854 struct svc_rqst *rqstp = sd->u.data; 855 struct page **pp = rqstp->rq_respages + rqstp->rq_resused; 856 struct page *page = buf->page; 857 size_t size; 858 int ret; 859 860 ret = buf->ops->confirm(pipe, buf); 861 if (unlikely(ret)) 862 return ret; 863 864 size = sd->len; 865 866 if (rqstp->rq_res.page_len == 0) { 867 get_page(page); 868 put_page(*pp); 869 *pp = page; 870 rqstp->rq_resused++; 871 rqstp->rq_res.page_base = buf->offset; 872 rqstp->rq_res.page_len = size; 873 } else if (page != pp[-1]) { 874 get_page(page); 875 if (*pp) 876 put_page(*pp); 877 *pp = page; 878 rqstp->rq_resused++; 879 rqstp->rq_res.page_len += size; 880 } else 881 rqstp->rq_res.page_len += size; 882 883 return size; 884 } 885 886 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, 887 struct splice_desc *sd) 888 { 889 return __splice_from_pipe(pipe, sd, nfsd_splice_actor); 890 } 891 892 static inline int svc_msnfs(struct svc_fh *ffhp) 893 { 894 #ifdef MSNFS 895 return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS); 896 #else 897 return 0; 898 #endif 899 } 900 901 static __be32 902 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 903 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 904 { 905 struct inode *inode; 906 struct raparms *ra; 907 mm_segment_t oldfs; 908 __be32 err; 909 int host_err; 910 911 err = nfserr_perm; 912 inode = file->f_path.dentry->d_inode; 913 914 if (svc_msnfs(fhp) && !lock_may_read(inode, offset, *count)) 915 goto out; 916 917 /* Get readahead parameters */ 918 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 919 920 if (ra && ra->p_set) 921 file->f_ra = ra->p_ra; 922 923 if (file->f_op->splice_read && rqstp->rq_splice_ok) { 924 struct splice_desc sd = { 925 .len = 0, 926 .total_len = *count, 927 .pos = offset, 928 .u.data = rqstp, 929 }; 930 931 rqstp->rq_resused = 1; 932 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); 933 } else { 934 oldfs = get_fs(); 935 set_fs(KERNEL_DS); 936 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 937 set_fs(oldfs); 938 } 939 940 /* Write back readahead params */ 941 if (ra) { 942 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex]; 943 spin_lock(&rab->pb_lock); 944 ra->p_ra = file->f_ra; 945 ra->p_set = 1; 946 ra->p_count--; 947 spin_unlock(&rab->pb_lock); 948 } 949 950 if (host_err >= 0) { 951 nfsdstats.io_read += host_err; 952 *count = host_err; 953 err = 0; 954 fsnotify_access(file->f_path.dentry); 955 } else 956 err = nfserrno(host_err); 957 out: 958 return err; 959 } 960 961 static void kill_suid(struct dentry *dentry) 962 { 963 struct iattr ia; 964 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; 965 966 mutex_lock(&dentry->d_inode->i_mutex); 967 notify_change(dentry, &ia); 968 mutex_unlock(&dentry->d_inode->i_mutex); 969 } 970 971 /* 972 * Gathered writes: If another process is currently writing to the file, 973 * there's a high chance this is another nfsd (triggered by a bulk write 974 * from a client's biod). Rather than syncing the file with each write 975 * request, we sleep for 10 msec. 976 * 977 * I don't know if this roughly approximates C. Juszak's idea of 978 * gathered writes, but it's a nice and simple solution (IMHO), and it 979 * seems to work:-) 980 * 981 * Note: we do this only in the NFSv2 case, since v3 and higher have a 982 * better tool (separate unstable writes and commits) for solving this 983 * problem. 984 */ 985 static int wait_for_concurrent_writes(struct file *file) 986 { 987 struct inode *inode = file->f_path.dentry->d_inode; 988 static ino_t last_ino; 989 static dev_t last_dev; 990 int err = 0; 991 992 if (atomic_read(&inode->i_writecount) > 1 993 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 994 dprintk("nfsd: write defer %d\n", task_pid_nr(current)); 995 msleep(10); 996 dprintk("nfsd: write resume %d\n", task_pid_nr(current)); 997 } 998 999 if (inode->i_state & I_DIRTY) { 1000 dprintk("nfsd: write sync %d\n", task_pid_nr(current)); 1001 err = vfs_fsync(file, file->f_path.dentry, 0); 1002 } 1003 last_ino = inode->i_ino; 1004 last_dev = inode->i_sb->s_dev; 1005 return err; 1006 } 1007 1008 static __be32 1009 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1010 loff_t offset, struct kvec *vec, int vlen, 1011 unsigned long *cnt, int *stablep) 1012 { 1013 struct svc_export *exp; 1014 struct dentry *dentry; 1015 struct inode *inode; 1016 mm_segment_t oldfs; 1017 __be32 err = 0; 1018 int host_err; 1019 int stable = *stablep; 1020 int use_wgather; 1021 1022 #ifdef MSNFS 1023 err = nfserr_perm; 1024 1025 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1026 (!lock_may_write(file->f_path.dentry->d_inode, offset, *cnt))) 1027 goto out; 1028 #endif 1029 1030 dentry = file->f_path.dentry; 1031 inode = dentry->d_inode; 1032 exp = fhp->fh_export; 1033 1034 /* 1035 * Request sync writes if 1036 * - the sync export option has been set, or 1037 * - the client requested O_SYNC behavior (NFSv3 feature). 1038 * - The file system doesn't support fsync(). 1039 * When NFSv2 gathered writes have been configured for this volume, 1040 * flushing the data to disk is handled separately below. 1041 */ 1042 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); 1043 1044 if (!file->f_op->fsync) {/* COMMIT3 cannot work */ 1045 stable = 2; 1046 *stablep = 2; /* FILE_SYNC */ 1047 } 1048 1049 if (!EX_ISSYNC(exp)) 1050 stable = 0; 1051 if (stable && !use_wgather) { 1052 spin_lock(&file->f_lock); 1053 file->f_flags |= O_SYNC; 1054 spin_unlock(&file->f_lock); 1055 } 1056 1057 /* Write the data. */ 1058 oldfs = get_fs(); set_fs(KERNEL_DS); 1059 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); 1060 set_fs(oldfs); 1061 if (host_err < 0) 1062 goto out_nfserr; 1063 *cnt = host_err; 1064 nfsdstats.io_write += host_err; 1065 fsnotify_modify(file->f_path.dentry); 1066 1067 /* clear setuid/setgid flag after write */ 1068 if (inode->i_mode & (S_ISUID | S_ISGID)) 1069 kill_suid(dentry); 1070 1071 if (stable && use_wgather) 1072 host_err = wait_for_concurrent_writes(file); 1073 1074 out_nfserr: 1075 dprintk("nfsd: write complete host_err=%d\n", host_err); 1076 if (host_err >= 0) 1077 err = 0; 1078 else 1079 err = nfserrno(host_err); 1080 out: 1081 return err; 1082 } 1083 1084 /* 1085 * Read data from a file. count must contain the requested read count 1086 * on entry. On return, *count contains the number of bytes actually read. 1087 * N.B. After this call fhp needs an fh_put 1088 */ 1089 __be32 1090 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1091 loff_t offset, struct kvec *vec, int vlen, 1092 unsigned long *count) 1093 { 1094 __be32 err; 1095 1096 if (file) { 1097 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1098 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE); 1099 if (err) 1100 goto out; 1101 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1102 } else { 1103 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); 1104 if (err) 1105 goto out; 1106 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1107 nfsd_close(file); 1108 } 1109 out: 1110 return err; 1111 } 1112 1113 /* 1114 * Write data to a file. 1115 * The stable flag requests synchronous writes. 1116 * N.B. After this call fhp needs an fh_put 1117 */ 1118 __be32 1119 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1120 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, 1121 int *stablep) 1122 { 1123 __be32 err = 0; 1124 1125 if (file) { 1126 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1127 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE); 1128 if (err) 1129 goto out; 1130 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1131 stablep); 1132 } else { 1133 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); 1134 if (err) 1135 goto out; 1136 1137 if (cnt) 1138 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1139 cnt, stablep); 1140 nfsd_close(file); 1141 } 1142 out: 1143 return err; 1144 } 1145 1146 #ifdef CONFIG_NFSD_V3 1147 /* 1148 * Commit all pending writes to stable storage. 1149 * 1150 * Note: we only guarantee that data that lies within the range specified 1151 * by the 'offset' and 'count' parameters will be synced. 1152 * 1153 * Unfortunately we cannot lock the file to make sure we return full WCC 1154 * data to the client, as locking happens lower down in the filesystem. 1155 */ 1156 __be32 1157 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1158 loff_t offset, unsigned long count) 1159 { 1160 struct file *file; 1161 loff_t end = LLONG_MAX; 1162 __be32 err = nfserr_inval; 1163 1164 if (offset < 0) 1165 goto out; 1166 if (count != 0) { 1167 end = offset + (loff_t)count - 1; 1168 if (end < offset) 1169 goto out; 1170 } 1171 1172 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); 1173 if (err) 1174 goto out; 1175 if (EX_ISSYNC(fhp->fh_export)) { 1176 int err2 = vfs_fsync_range(file, file->f_path.dentry, 1177 offset, end, 0); 1178 1179 if (err2 != -EINVAL) 1180 err = nfserrno(err2); 1181 else 1182 err = nfserr_notsupp; 1183 } 1184 1185 nfsd_close(file); 1186 out: 1187 return err; 1188 } 1189 #endif /* CONFIG_NFSD_V3 */ 1190 1191 static __be32 1192 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp, 1193 struct iattr *iap) 1194 { 1195 /* 1196 * Mode has already been set earlier in create: 1197 */ 1198 iap->ia_valid &= ~ATTR_MODE; 1199 /* 1200 * Setting uid/gid works only for root. Irix appears to 1201 * send along the gid on create when it tries to implement 1202 * setgid directories via NFS: 1203 */ 1204 if (current_fsuid() != 0) 1205 iap->ia_valid &= ~(ATTR_UID|ATTR_GID); 1206 if (iap->ia_valid) 1207 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1208 return 0; 1209 } 1210 1211 /* HPUX client sometimes creates a file in mode 000, and sets size to 0. 1212 * setting size to 0 may fail for some specific file systems by the permission 1213 * checking which requires WRITE permission but the mode is 000. 1214 * we ignore the resizing(to 0) on the just new created file, since the size is 1215 * 0 after file created. 1216 * 1217 * call this only after vfs_create() is called. 1218 * */ 1219 static void 1220 nfsd_check_ignore_resizing(struct iattr *iap) 1221 { 1222 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) 1223 iap->ia_valid &= ~ATTR_SIZE; 1224 } 1225 1226 /* 1227 * Create a file (regular, directory, device, fifo); UNIX sockets 1228 * not yet implemented. 1229 * If the response fh has been verified, the parent directory should 1230 * already be locked. Note that the parent directory is left locked. 1231 * 1232 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1233 */ 1234 __be32 1235 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1236 char *fname, int flen, struct iattr *iap, 1237 int type, dev_t rdev, struct svc_fh *resfhp) 1238 { 1239 struct dentry *dentry, *dchild = NULL; 1240 struct inode *dirp; 1241 __be32 err; 1242 __be32 err2; 1243 int host_err; 1244 1245 err = nfserr_perm; 1246 if (!flen) 1247 goto out; 1248 err = nfserr_exist; 1249 if (isdotent(fname, flen)) 1250 goto out; 1251 1252 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1253 if (err) 1254 goto out; 1255 1256 dentry = fhp->fh_dentry; 1257 dirp = dentry->d_inode; 1258 1259 err = nfserr_notdir; 1260 if (!dirp->i_op->lookup) 1261 goto out; 1262 /* 1263 * Check whether the response file handle has been verified yet. 1264 * If it has, the parent directory should already be locked. 1265 */ 1266 if (!resfhp->fh_dentry) { 1267 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1268 fh_lock_nested(fhp, I_MUTEX_PARENT); 1269 dchild = lookup_one_len(fname, dentry, flen); 1270 host_err = PTR_ERR(dchild); 1271 if (IS_ERR(dchild)) 1272 goto out_nfserr; 1273 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1274 if (err) 1275 goto out; 1276 } else { 1277 /* called from nfsd_proc_create */ 1278 dchild = dget(resfhp->fh_dentry); 1279 if (!fhp->fh_locked) { 1280 /* not actually possible */ 1281 printk(KERN_ERR 1282 "nfsd_create: parent %s/%s not locked!\n", 1283 dentry->d_parent->d_name.name, 1284 dentry->d_name.name); 1285 err = nfserr_io; 1286 goto out; 1287 } 1288 } 1289 /* 1290 * Make sure the child dentry is still negative ... 1291 */ 1292 err = nfserr_exist; 1293 if (dchild->d_inode) { 1294 dprintk("nfsd_create: dentry %s/%s not negative!\n", 1295 dentry->d_name.name, dchild->d_name.name); 1296 goto out; 1297 } 1298 1299 if (!(iap->ia_valid & ATTR_MODE)) 1300 iap->ia_mode = 0; 1301 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1302 1303 err = nfserr_inval; 1304 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) { 1305 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", 1306 type); 1307 goto out; 1308 } 1309 1310 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1311 if (host_err) 1312 goto out_nfserr; 1313 1314 /* 1315 * Get the dir op function pointer. 1316 */ 1317 err = 0; 1318 switch (type) { 1319 case S_IFREG: 1320 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1321 if (!host_err) 1322 nfsd_check_ignore_resizing(iap); 1323 break; 1324 case S_IFDIR: 1325 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1326 break; 1327 case S_IFCHR: 1328 case S_IFBLK: 1329 case S_IFIFO: 1330 case S_IFSOCK: 1331 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1332 break; 1333 } 1334 if (host_err < 0) { 1335 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1336 goto out_nfserr; 1337 } 1338 1339 err = nfsd_create_setattr(rqstp, resfhp, iap); 1340 1341 /* 1342 * nfsd_setattr already committed the child. Transactional filesystems 1343 * had a chance to commit changes for both parent and child 1344 * simultaneously making the following commit_metadata a noop. 1345 */ 1346 err2 = nfserrno(commit_metadata(fhp)); 1347 if (err2) 1348 err = err2; 1349 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1350 /* 1351 * Update the file handle to get the new inode info. 1352 */ 1353 if (!err) 1354 err = fh_update(resfhp); 1355 out: 1356 if (dchild && !IS_ERR(dchild)) 1357 dput(dchild); 1358 return err; 1359 1360 out_nfserr: 1361 err = nfserrno(host_err); 1362 goto out; 1363 } 1364 1365 #ifdef CONFIG_NFSD_V3 1366 /* 1367 * NFSv3 version of nfsd_create 1368 */ 1369 __be32 1370 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, 1371 char *fname, int flen, struct iattr *iap, 1372 struct svc_fh *resfhp, int createmode, u32 *verifier, 1373 int *truncp, int *created) 1374 { 1375 struct dentry *dentry, *dchild = NULL; 1376 struct inode *dirp; 1377 __be32 err; 1378 int host_err; 1379 __u32 v_mtime=0, v_atime=0; 1380 1381 err = nfserr_perm; 1382 if (!flen) 1383 goto out; 1384 err = nfserr_exist; 1385 if (isdotent(fname, flen)) 1386 goto out; 1387 if (!(iap->ia_valid & ATTR_MODE)) 1388 iap->ia_mode = 0; 1389 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1390 if (err) 1391 goto out; 1392 1393 dentry = fhp->fh_dentry; 1394 dirp = dentry->d_inode; 1395 1396 /* Get all the sanity checks out of the way before 1397 * we lock the parent. */ 1398 err = nfserr_notdir; 1399 if (!dirp->i_op->lookup) 1400 goto out; 1401 fh_lock_nested(fhp, I_MUTEX_PARENT); 1402 1403 /* 1404 * Compose the response file handle. 1405 */ 1406 dchild = lookup_one_len(fname, dentry, flen); 1407 host_err = PTR_ERR(dchild); 1408 if (IS_ERR(dchild)) 1409 goto out_nfserr; 1410 1411 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1412 if (err) 1413 goto out; 1414 1415 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1416 /* solaris7 gets confused (bugid 4218508) if these have 1417 * the high bit set, so just clear the high bits. If this is 1418 * ever changed to use different attrs for storing the 1419 * verifier, then do_open_lookup() will also need to be fixed 1420 * accordingly. 1421 */ 1422 v_mtime = verifier[0]&0x7fffffff; 1423 v_atime = verifier[1]&0x7fffffff; 1424 } 1425 1426 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1427 if (host_err) 1428 goto out_nfserr; 1429 if (dchild->d_inode) { 1430 err = 0; 1431 1432 switch (createmode) { 1433 case NFS3_CREATE_UNCHECKED: 1434 if (! S_ISREG(dchild->d_inode->i_mode)) 1435 err = nfserr_exist; 1436 else if (truncp) { 1437 /* in nfsv4, we need to treat this case a little 1438 * differently. we don't want to truncate the 1439 * file now; this would be wrong if the OPEN 1440 * fails for some other reason. furthermore, 1441 * if the size is nonzero, we should ignore it 1442 * according to spec! 1443 */ 1444 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1445 } 1446 else { 1447 iap->ia_valid &= ATTR_SIZE; 1448 goto set_attr; 1449 } 1450 break; 1451 case NFS3_CREATE_EXCLUSIVE: 1452 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1453 && dchild->d_inode->i_atime.tv_sec == v_atime 1454 && dchild->d_inode->i_size == 0 ) 1455 break; 1456 /* fallthru */ 1457 case NFS3_CREATE_GUARDED: 1458 err = nfserr_exist; 1459 } 1460 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1461 goto out; 1462 } 1463 1464 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1465 if (host_err < 0) { 1466 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1467 goto out_nfserr; 1468 } 1469 if (created) 1470 *created = 1; 1471 1472 nfsd_check_ignore_resizing(iap); 1473 1474 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1475 /* Cram the verifier into atime/mtime */ 1476 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1477 | ATTR_MTIME_SET|ATTR_ATIME_SET; 1478 /* XXX someone who knows this better please fix it for nsec */ 1479 iap->ia_mtime.tv_sec = v_mtime; 1480 iap->ia_atime.tv_sec = v_atime; 1481 iap->ia_mtime.tv_nsec = 0; 1482 iap->ia_atime.tv_nsec = 0; 1483 } 1484 1485 set_attr: 1486 err = nfsd_create_setattr(rqstp, resfhp, iap); 1487 1488 /* 1489 * nfsd_setattr already committed the child (and possibly also the parent). 1490 */ 1491 if (!err) 1492 err = nfserrno(commit_metadata(fhp)); 1493 1494 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1495 /* 1496 * Update the filehandle to get the new inode info. 1497 */ 1498 if (!err) 1499 err = fh_update(resfhp); 1500 1501 out: 1502 fh_unlock(fhp); 1503 if (dchild && !IS_ERR(dchild)) 1504 dput(dchild); 1505 return err; 1506 1507 out_nfserr: 1508 err = nfserrno(host_err); 1509 goto out; 1510 } 1511 #endif /* CONFIG_NFSD_V3 */ 1512 1513 /* 1514 * Read a symlink. On entry, *lenp must contain the maximum path length that 1515 * fits into the buffer. On return, it contains the true length. 1516 * N.B. After this call fhp needs an fh_put 1517 */ 1518 __be32 1519 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1520 { 1521 struct dentry *dentry; 1522 struct inode *inode; 1523 mm_segment_t oldfs; 1524 __be32 err; 1525 int host_err; 1526 1527 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); 1528 if (err) 1529 goto out; 1530 1531 dentry = fhp->fh_dentry; 1532 inode = dentry->d_inode; 1533 1534 err = nfserr_inval; 1535 if (!inode->i_op->readlink) 1536 goto out; 1537 1538 touch_atime(fhp->fh_export->ex_path.mnt, dentry); 1539 /* N.B. Why does this call need a get_fs()?? 1540 * Remove the set_fs and watch the fireworks:-) --okir 1541 */ 1542 1543 oldfs = get_fs(); set_fs(KERNEL_DS); 1544 host_err = inode->i_op->readlink(dentry, buf, *lenp); 1545 set_fs(oldfs); 1546 1547 if (host_err < 0) 1548 goto out_nfserr; 1549 *lenp = host_err; 1550 err = 0; 1551 out: 1552 return err; 1553 1554 out_nfserr: 1555 err = nfserrno(host_err); 1556 goto out; 1557 } 1558 1559 /* 1560 * Create a symlink and look up its inode 1561 * N.B. After this call _both_ fhp and resfhp need an fh_put 1562 */ 1563 __be32 1564 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1565 char *fname, int flen, 1566 char *path, int plen, 1567 struct svc_fh *resfhp, 1568 struct iattr *iap) 1569 { 1570 struct dentry *dentry, *dnew; 1571 __be32 err, cerr; 1572 int host_err; 1573 1574 err = nfserr_noent; 1575 if (!flen || !plen) 1576 goto out; 1577 err = nfserr_exist; 1578 if (isdotent(fname, flen)) 1579 goto out; 1580 1581 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1582 if (err) 1583 goto out; 1584 fh_lock(fhp); 1585 dentry = fhp->fh_dentry; 1586 dnew = lookup_one_len(fname, dentry, flen); 1587 host_err = PTR_ERR(dnew); 1588 if (IS_ERR(dnew)) 1589 goto out_nfserr; 1590 1591 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1592 if (host_err) 1593 goto out_nfserr; 1594 1595 if (unlikely(path[plen] != 0)) { 1596 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1597 if (path_alloced == NULL) 1598 host_err = -ENOMEM; 1599 else { 1600 strncpy(path_alloced, path, plen); 1601 path_alloced[plen] = 0; 1602 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced); 1603 kfree(path_alloced); 1604 } 1605 } else 1606 host_err = vfs_symlink(dentry->d_inode, dnew, path); 1607 err = nfserrno(host_err); 1608 if (!err) 1609 err = nfserrno(commit_metadata(fhp)); 1610 fh_unlock(fhp); 1611 1612 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1613 1614 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1615 dput(dnew); 1616 if (err==0) err = cerr; 1617 out: 1618 return err; 1619 1620 out_nfserr: 1621 err = nfserrno(host_err); 1622 goto out; 1623 } 1624 1625 /* 1626 * Create a hardlink 1627 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1628 */ 1629 __be32 1630 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1631 char *name, int len, struct svc_fh *tfhp) 1632 { 1633 struct dentry *ddir, *dnew, *dold; 1634 struct inode *dirp, *dest; 1635 __be32 err; 1636 int host_err; 1637 1638 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); 1639 if (err) 1640 goto out; 1641 err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP); 1642 if (err) 1643 goto out; 1644 1645 err = nfserr_perm; 1646 if (!len) 1647 goto out; 1648 err = nfserr_exist; 1649 if (isdotent(name, len)) 1650 goto out; 1651 1652 fh_lock_nested(ffhp, I_MUTEX_PARENT); 1653 ddir = ffhp->fh_dentry; 1654 dirp = ddir->d_inode; 1655 1656 dnew = lookup_one_len(name, ddir, len); 1657 host_err = PTR_ERR(dnew); 1658 if (IS_ERR(dnew)) 1659 goto out_nfserr; 1660 1661 dold = tfhp->fh_dentry; 1662 dest = dold->d_inode; 1663 1664 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt); 1665 if (host_err) { 1666 err = nfserrno(host_err); 1667 goto out_dput; 1668 } 1669 host_err = vfs_link(dold, dirp, dnew); 1670 if (!host_err) { 1671 err = nfserrno(commit_metadata(ffhp)); 1672 if (!err) 1673 err = nfserrno(commit_metadata(tfhp)); 1674 } else { 1675 if (host_err == -EXDEV && rqstp->rq_vers == 2) 1676 err = nfserr_acces; 1677 else 1678 err = nfserrno(host_err); 1679 } 1680 mnt_drop_write(tfhp->fh_export->ex_path.mnt); 1681 out_dput: 1682 dput(dnew); 1683 out_unlock: 1684 fh_unlock(ffhp); 1685 out: 1686 return err; 1687 1688 out_nfserr: 1689 err = nfserrno(host_err); 1690 goto out_unlock; 1691 } 1692 1693 /* 1694 * Rename a file 1695 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1696 */ 1697 __be32 1698 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1699 struct svc_fh *tfhp, char *tname, int tlen) 1700 { 1701 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1702 struct inode *fdir, *tdir; 1703 __be32 err; 1704 int host_err; 1705 1706 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); 1707 if (err) 1708 goto out; 1709 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE); 1710 if (err) 1711 goto out; 1712 1713 fdentry = ffhp->fh_dentry; 1714 fdir = fdentry->d_inode; 1715 1716 tdentry = tfhp->fh_dentry; 1717 tdir = tdentry->d_inode; 1718 1719 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; 1720 if (ffhp->fh_export != tfhp->fh_export) 1721 goto out; 1722 1723 err = nfserr_perm; 1724 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1725 goto out; 1726 1727 /* cannot use fh_lock as we need deadlock protective ordering 1728 * so do it by hand */ 1729 trap = lock_rename(tdentry, fdentry); 1730 ffhp->fh_locked = tfhp->fh_locked = 1; 1731 fill_pre_wcc(ffhp); 1732 fill_pre_wcc(tfhp); 1733 1734 odentry = lookup_one_len(fname, fdentry, flen); 1735 host_err = PTR_ERR(odentry); 1736 if (IS_ERR(odentry)) 1737 goto out_nfserr; 1738 1739 host_err = -ENOENT; 1740 if (!odentry->d_inode) 1741 goto out_dput_old; 1742 host_err = -EINVAL; 1743 if (odentry == trap) 1744 goto out_dput_old; 1745 1746 ndentry = lookup_one_len(tname, tdentry, tlen); 1747 host_err = PTR_ERR(ndentry); 1748 if (IS_ERR(ndentry)) 1749 goto out_dput_old; 1750 host_err = -ENOTEMPTY; 1751 if (ndentry == trap) 1752 goto out_dput_new; 1753 1754 if (svc_msnfs(ffhp) && 1755 ((atomic_read(&odentry->d_count) > 1) 1756 || (atomic_read(&ndentry->d_count) > 1))) { 1757 host_err = -EPERM; 1758 goto out_dput_new; 1759 } 1760 1761 host_err = -EXDEV; 1762 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) 1763 goto out_dput_new; 1764 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt); 1765 if (host_err) 1766 goto out_dput_new; 1767 1768 host_err = vfs_rename(fdir, odentry, tdir, ndentry); 1769 if (!host_err) { 1770 host_err = commit_metadata(tfhp); 1771 if (!host_err) 1772 host_err = commit_metadata(ffhp); 1773 } 1774 1775 mnt_drop_write(ffhp->fh_export->ex_path.mnt); 1776 1777 out_dput_new: 1778 dput(ndentry); 1779 out_dput_old: 1780 dput(odentry); 1781 out_nfserr: 1782 err = nfserrno(host_err); 1783 1784 /* we cannot reply on fh_unlock on the two filehandles, 1785 * as that would do the wrong thing if the two directories 1786 * were the same, so again we do it by hand 1787 */ 1788 fill_post_wcc(ffhp); 1789 fill_post_wcc(tfhp); 1790 unlock_rename(tdentry, fdentry); 1791 ffhp->fh_locked = tfhp->fh_locked = 0; 1792 1793 out: 1794 return err; 1795 } 1796 1797 /* 1798 * Unlink a file or directory 1799 * N.B. After this call fhp needs an fh_put 1800 */ 1801 __be32 1802 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1803 char *fname, int flen) 1804 { 1805 struct dentry *dentry, *rdentry; 1806 struct inode *dirp; 1807 __be32 err; 1808 int host_err; 1809 1810 err = nfserr_acces; 1811 if (!flen || isdotent(fname, flen)) 1812 goto out; 1813 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); 1814 if (err) 1815 goto out; 1816 1817 fh_lock_nested(fhp, I_MUTEX_PARENT); 1818 dentry = fhp->fh_dentry; 1819 dirp = dentry->d_inode; 1820 1821 rdentry = lookup_one_len(fname, dentry, flen); 1822 host_err = PTR_ERR(rdentry); 1823 if (IS_ERR(rdentry)) 1824 goto out_nfserr; 1825 1826 if (!rdentry->d_inode) { 1827 dput(rdentry); 1828 err = nfserr_noent; 1829 goto out; 1830 } 1831 1832 if (!type) 1833 type = rdentry->d_inode->i_mode & S_IFMT; 1834 1835 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1836 if (host_err) 1837 goto out_nfserr; 1838 1839 if (type != S_IFDIR) { /* It's UNLINK */ 1840 #ifdef MSNFS 1841 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1842 (atomic_read(&rdentry->d_count) > 1)) { 1843 host_err = -EPERM; 1844 } else 1845 #endif 1846 host_err = vfs_unlink(dirp, rdentry); 1847 } else { /* It's RMDIR */ 1848 host_err = vfs_rmdir(dirp, rdentry); 1849 } 1850 1851 dput(rdentry); 1852 1853 if (!host_err) 1854 host_err = commit_metadata(fhp); 1855 1856 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1857 out_nfserr: 1858 err = nfserrno(host_err); 1859 out: 1860 return err; 1861 } 1862 1863 /* 1864 * We do this buffering because we must not call back into the file 1865 * system's ->lookup() method from the filldir callback. That may well 1866 * deadlock a number of file systems. 1867 * 1868 * This is based heavily on the implementation of same in XFS. 1869 */ 1870 struct buffered_dirent { 1871 u64 ino; 1872 loff_t offset; 1873 int namlen; 1874 unsigned int d_type; 1875 char name[]; 1876 }; 1877 1878 struct readdir_data { 1879 char *dirent; 1880 size_t used; 1881 int full; 1882 }; 1883 1884 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, 1885 loff_t offset, u64 ino, unsigned int d_type) 1886 { 1887 struct readdir_data *buf = __buf; 1888 struct buffered_dirent *de = (void *)(buf->dirent + buf->used); 1889 unsigned int reclen; 1890 1891 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); 1892 if (buf->used + reclen > PAGE_SIZE) { 1893 buf->full = 1; 1894 return -EINVAL; 1895 } 1896 1897 de->namlen = namlen; 1898 de->offset = offset; 1899 de->ino = ino; 1900 de->d_type = d_type; 1901 memcpy(de->name, name, namlen); 1902 buf->used += reclen; 1903 1904 return 0; 1905 } 1906 1907 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, 1908 struct readdir_cd *cdp, loff_t *offsetp) 1909 { 1910 struct readdir_data buf; 1911 struct buffered_dirent *de; 1912 int host_err; 1913 int size; 1914 loff_t offset; 1915 1916 buf.dirent = (void *)__get_free_page(GFP_KERNEL); 1917 if (!buf.dirent) 1918 return nfserrno(-ENOMEM); 1919 1920 offset = *offsetp; 1921 1922 while (1) { 1923 struct inode *dir_inode = file->f_path.dentry->d_inode; 1924 unsigned int reclen; 1925 1926 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1927 buf.used = 0; 1928 buf.full = 0; 1929 1930 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf); 1931 if (buf.full) 1932 host_err = 0; 1933 1934 if (host_err < 0) 1935 break; 1936 1937 size = buf.used; 1938 1939 if (!size) 1940 break; 1941 1942 /* 1943 * Various filldir functions may end up calling back into 1944 * lookup_one_len() and the file system's ->lookup() method. 1945 * These expect i_mutex to be held, as it would within readdir. 1946 */ 1947 host_err = mutex_lock_killable(&dir_inode->i_mutex); 1948 if (host_err) 1949 break; 1950 1951 de = (struct buffered_dirent *)buf.dirent; 1952 while (size > 0) { 1953 offset = de->offset; 1954 1955 if (func(cdp, de->name, de->namlen, de->offset, 1956 de->ino, de->d_type)) 1957 break; 1958 1959 if (cdp->err != nfs_ok) 1960 break; 1961 1962 reclen = ALIGN(sizeof(*de) + de->namlen, 1963 sizeof(u64)); 1964 size -= reclen; 1965 de = (struct buffered_dirent *)((char *)de + reclen); 1966 } 1967 mutex_unlock(&dir_inode->i_mutex); 1968 if (size > 0) /* We bailed out early */ 1969 break; 1970 1971 offset = vfs_llseek(file, 0, SEEK_CUR); 1972 } 1973 1974 free_page((unsigned long)(buf.dirent)); 1975 1976 if (host_err) 1977 return nfserrno(host_err); 1978 1979 *offsetp = offset; 1980 return cdp->err; 1981 } 1982 1983 /* 1984 * Read entries from a directory. 1985 * The NFSv3/4 verifier we ignore for now. 1986 */ 1987 __be32 1988 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 1989 struct readdir_cd *cdp, filldir_t func) 1990 { 1991 __be32 err; 1992 struct file *file; 1993 loff_t offset = *offsetp; 1994 1995 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file); 1996 if (err) 1997 goto out; 1998 1999 offset = vfs_llseek(file, offset, 0); 2000 if (offset < 0) { 2001 err = nfserrno((int)offset); 2002 goto out_close; 2003 } 2004 2005 err = nfsd_buffered_readdir(file, func, cdp, offsetp); 2006 2007 if (err == nfserr_eof || err == nfserr_toosmall) 2008 err = nfs_ok; /* can still be found in ->err */ 2009 out_close: 2010 nfsd_close(file); 2011 out: 2012 return err; 2013 } 2014 2015 /* 2016 * Get file system stats 2017 * N.B. After this call fhp needs an fh_put 2018 */ 2019 __be32 2020 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) 2021 { 2022 __be32 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); 2023 if (!err && vfs_statfs(fhp->fh_dentry,stat)) 2024 err = nfserr_io; 2025 return err; 2026 } 2027 2028 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) 2029 { 2030 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; 2031 } 2032 2033 /* 2034 * Check for a user's access permissions to this inode. 2035 */ 2036 __be32 2037 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, 2038 struct dentry *dentry, int acc) 2039 { 2040 struct inode *inode = dentry->d_inode; 2041 struct path path; 2042 int err; 2043 2044 if (acc == NFSD_MAY_NOP) 2045 return 0; 2046 #if 0 2047 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 2048 acc, 2049 (acc & NFSD_MAY_READ)? " read" : "", 2050 (acc & NFSD_MAY_WRITE)? " write" : "", 2051 (acc & NFSD_MAY_EXEC)? " exec" : "", 2052 (acc & NFSD_MAY_SATTR)? " sattr" : "", 2053 (acc & NFSD_MAY_TRUNC)? " trunc" : "", 2054 (acc & NFSD_MAY_LOCK)? " lock" : "", 2055 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", 2056 inode->i_mode, 2057 IS_IMMUTABLE(inode)? " immut" : "", 2058 IS_APPEND(inode)? " append" : "", 2059 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); 2060 dprintk(" owner %d/%d user %d/%d\n", 2061 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); 2062 #endif 2063 2064 /* Normally we reject any write/sattr etc access on a read-only file 2065 * system. But if it is IRIX doing check on write-access for a 2066 * device special file, we ignore rofs. 2067 */ 2068 if (!(acc & NFSD_MAY_LOCAL_ACCESS)) 2069 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { 2070 if (exp_rdonly(rqstp, exp) || 2071 __mnt_is_readonly(exp->ex_path.mnt)) 2072 return nfserr_rofs; 2073 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) 2074 return nfserr_perm; 2075 } 2076 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) 2077 return nfserr_perm; 2078 2079 if (acc & NFSD_MAY_LOCK) { 2080 /* If we cannot rely on authentication in NLM requests, 2081 * just allow locks, otherwise require read permission, or 2082 * ownership 2083 */ 2084 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 2085 return 0; 2086 else 2087 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE; 2088 } 2089 /* 2090 * The file owner always gets access permission for accesses that 2091 * would normally be checked at open time. This is to make 2092 * file access work even when the client has done a fchmod(fd, 0). 2093 * 2094 * However, `cp foo bar' should fail nevertheless when bar is 2095 * readonly. A sensible way to do this might be to reject all 2096 * attempts to truncate a read-only file, because a creat() call 2097 * always implies file truncation. 2098 * ... but this isn't really fair. A process may reasonably call 2099 * ftruncate on an open file descriptor on a file with perm 000. 2100 * We must trust the client to do permission checking - using "ACCESS" 2101 * with NFSv3. 2102 */ 2103 if ((acc & NFSD_MAY_OWNER_OVERRIDE) && 2104 inode->i_uid == current_fsuid()) 2105 return 0; 2106 2107 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ 2108 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); 2109 2110 /* Allow read access to binaries even when mode 111 */ 2111 if (err == -EACCES && S_ISREG(inode->i_mode) && 2112 acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE)) 2113 err = inode_permission(inode, MAY_EXEC); 2114 if (err) 2115 goto nfsd_out; 2116 2117 /* Do integrity (permission) checking now, but defer incrementing 2118 * IMA counts to the actual file open. 2119 */ 2120 path.mnt = exp->ex_path.mnt; 2121 path.dentry = dentry; 2122 nfsd_out: 2123 return err? nfserrno(err) : 0; 2124 } 2125 2126 void 2127 nfsd_racache_shutdown(void) 2128 { 2129 struct raparms *raparm, *last_raparm; 2130 unsigned int i; 2131 2132 dprintk("nfsd: freeing readahead buffers.\n"); 2133 2134 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2135 raparm = raparm_hash[i].pb_head; 2136 while(raparm) { 2137 last_raparm = raparm; 2138 raparm = raparm->p_next; 2139 kfree(last_raparm); 2140 } 2141 raparm_hash[i].pb_head = NULL; 2142 } 2143 } 2144 /* 2145 * Initialize readahead param cache 2146 */ 2147 int 2148 nfsd_racache_init(int cache_size) 2149 { 2150 int i; 2151 int j = 0; 2152 int nperbucket; 2153 struct raparms **raparm = NULL; 2154 2155 2156 if (raparm_hash[0].pb_head) 2157 return 0; 2158 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE); 2159 if (nperbucket < 2) 2160 nperbucket = 2; 2161 cache_size = nperbucket * RAPARM_HASH_SIZE; 2162 2163 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); 2164 2165 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2166 spin_lock_init(&raparm_hash[i].pb_lock); 2167 2168 raparm = &raparm_hash[i].pb_head; 2169 for (j = 0; j < nperbucket; j++) { 2170 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL); 2171 if (!*raparm) 2172 goto out_nomem; 2173 raparm = &(*raparm)->p_next; 2174 } 2175 *raparm = NULL; 2176 } 2177 2178 nfsdstats.ra_size = cache_size; 2179 return 0; 2180 2181 out_nomem: 2182 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n"); 2183 nfsd_racache_shutdown(); 2184 return -ENOMEM; 2185 } 2186 2187 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 2188 struct posix_acl * 2189 nfsd_get_posix_acl(struct svc_fh *fhp, int type) 2190 { 2191 struct inode *inode = fhp->fh_dentry->d_inode; 2192 char *name; 2193 void *value = NULL; 2194 ssize_t size; 2195 struct posix_acl *acl; 2196 2197 if (!IS_POSIXACL(inode)) 2198 return ERR_PTR(-EOPNOTSUPP); 2199 2200 switch (type) { 2201 case ACL_TYPE_ACCESS: 2202 name = POSIX_ACL_XATTR_ACCESS; 2203 break; 2204 case ACL_TYPE_DEFAULT: 2205 name = POSIX_ACL_XATTR_DEFAULT; 2206 break; 2207 default: 2208 return ERR_PTR(-EOPNOTSUPP); 2209 } 2210 2211 size = nfsd_getxattr(fhp->fh_dentry, name, &value); 2212 if (size < 0) 2213 return ERR_PTR(size); 2214 2215 acl = posix_acl_from_xattr(value, size); 2216 kfree(value); 2217 return acl; 2218 } 2219 2220 int 2221 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) 2222 { 2223 struct inode *inode = fhp->fh_dentry->d_inode; 2224 char *name; 2225 void *value = NULL; 2226 size_t size; 2227 int error; 2228 2229 if (!IS_POSIXACL(inode) || 2230 !inode->i_op->setxattr || !inode->i_op->removexattr) 2231 return -EOPNOTSUPP; 2232 switch(type) { 2233 case ACL_TYPE_ACCESS: 2234 name = POSIX_ACL_XATTR_ACCESS; 2235 break; 2236 case ACL_TYPE_DEFAULT: 2237 name = POSIX_ACL_XATTR_DEFAULT; 2238 break; 2239 default: 2240 return -EOPNOTSUPP; 2241 } 2242 2243 if (acl && acl->a_count) { 2244 size = posix_acl_xattr_size(acl->a_count); 2245 value = kmalloc(size, GFP_KERNEL); 2246 if (!value) 2247 return -ENOMEM; 2248 error = posix_acl_to_xattr(acl, value, size); 2249 if (error < 0) 2250 goto getout; 2251 size = error; 2252 } else 2253 size = 0; 2254 2255 error = mnt_want_write(fhp->fh_export->ex_path.mnt); 2256 if (error) 2257 goto getout; 2258 if (size) 2259 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); 2260 else { 2261 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) 2262 error = 0; 2263 else { 2264 error = vfs_removexattr(fhp->fh_dentry, name); 2265 if (error == -ENODATA) 2266 error = 0; 2267 } 2268 } 2269 mnt_drop_write(fhp->fh_export->ex_path.mnt); 2270 2271 getout: 2272 kfree(value); 2273 return error; 2274 } 2275 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 2276