1 #define MSNFS /* HACK HACK */ 2 /* 3 * linux/fs/nfsd/vfs.c 4 * 5 * File operations used by nfsd. Some of these have been ripped from 6 * other parts of the kernel because they weren't exported, others 7 * are partial duplicates with added or changed functionality. 8 * 9 * Note that several functions dget() the dentry upon which they want 10 * to act, most notably those that create directory entries. Response 11 * dentry's are dput()'d if necessary in the release callback. 12 * So if you notice code paths that apparently fail to dput() the 13 * dentry, don't worry--they have been taken care of. 14 * 15 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de> 16 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp> 17 */ 18 19 #include <linux/fs.h> 20 #include <linux/file.h> 21 #include <linux/splice.h> 22 #include <linux/fcntl.h> 23 #include <linux/namei.h> 24 #include <linux/delay.h> 25 #include <linux/quotaops.h> 26 #include <linux/fsnotify.h> 27 #include <linux/posix_acl_xattr.h> 28 #include <linux/xattr.h> 29 #include <linux/jhash.h> 30 #include <linux/ima.h> 31 #include <asm/uaccess.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 /* 278 * Set various file attributes. 279 * N.B. After this call fhp needs an fh_put 280 */ 281 __be32 282 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 283 int check_guard, time_t guardtime) 284 { 285 struct dentry *dentry; 286 struct inode *inode; 287 int accmode = NFSD_MAY_SATTR; 288 int ftype = 0; 289 __be32 err; 290 int host_err; 291 int size_change = 0; 292 293 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) 294 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; 295 if (iap->ia_valid & ATTR_SIZE) 296 ftype = S_IFREG; 297 298 /* Get inode */ 299 err = fh_verify(rqstp, fhp, ftype, accmode); 300 if (err) 301 goto out; 302 303 dentry = fhp->fh_dentry; 304 inode = dentry->d_inode; 305 306 /* Ignore any mode updates on symlinks */ 307 if (S_ISLNK(inode->i_mode)) 308 iap->ia_valid &= ~ATTR_MODE; 309 310 if (!iap->ia_valid) 311 goto out; 312 313 /* 314 * NFSv2 does not differentiate between "set-[ac]time-to-now" 315 * which only requires access, and "set-[ac]time-to-X" which 316 * requires ownership. 317 * So if it looks like it might be "set both to the same time which 318 * is close to now", and if inode_change_ok fails, then we 319 * convert to "set to now" instead of "set to explicit time" 320 * 321 * We only call inode_change_ok as the last test as technically 322 * it is not an interface that we should be using. It is only 323 * valid if the filesystem does not define it's own i_op->setattr. 324 */ 325 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) 326 #define MAX_TOUCH_TIME_ERROR (30*60) 327 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && 328 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) { 329 /* 330 * Looks probable. 331 * 332 * Now just make sure time is in the right ballpark. 333 * Solaris, at least, doesn't seem to care what the time 334 * request is. We require it be within 30 minutes of now. 335 */ 336 time_t delta = iap->ia_atime.tv_sec - get_seconds(); 337 if (delta < 0) 338 delta = -delta; 339 if (delta < MAX_TOUCH_TIME_ERROR && 340 inode_change_ok(inode, iap) != 0) { 341 /* 342 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME. 343 * This will cause notify_change to set these times 344 * to "now" 345 */ 346 iap->ia_valid &= ~BOTH_TIME_SET; 347 } 348 } 349 350 /* 351 * The size case is special. 352 * It changes the file as well as the attributes. 353 */ 354 if (iap->ia_valid & ATTR_SIZE) { 355 if (iap->ia_size < inode->i_size) { 356 err = nfsd_permission(rqstp, fhp->fh_export, dentry, 357 NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE); 358 if (err) 359 goto out; 360 } 361 362 /* 363 * If we are changing the size of the file, then 364 * we need to break all leases. 365 */ 366 host_err = break_lease(inode, FMODE_WRITE | O_NONBLOCK); 367 if (host_err == -EWOULDBLOCK) 368 host_err = -ETIMEDOUT; 369 if (host_err) /* ENOMEM or EWOULDBLOCK */ 370 goto out_nfserr; 371 372 host_err = get_write_access(inode); 373 if (host_err) 374 goto out_nfserr; 375 376 size_change = 1; 377 host_err = locks_verify_truncate(inode, NULL, iap->ia_size); 378 if (host_err) { 379 put_write_access(inode); 380 goto out_nfserr; 381 } 382 vfs_dq_init(inode); 383 } 384 385 /* sanitize the mode change */ 386 if (iap->ia_valid & ATTR_MODE) { 387 iap->ia_mode &= S_IALLUGO; 388 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); 389 } 390 391 /* Revoke setuid/setgid on chown */ 392 if (!S_ISDIR(inode->i_mode) && 393 (((iap->ia_valid & ATTR_UID) && iap->ia_uid != inode->i_uid) || 394 ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid))) { 395 iap->ia_valid |= ATTR_KILL_PRIV; 396 if (iap->ia_valid & ATTR_MODE) { 397 /* we're setting mode too, just clear the s*id bits */ 398 iap->ia_mode &= ~S_ISUID; 399 if (iap->ia_mode & S_IXGRP) 400 iap->ia_mode &= ~S_ISGID; 401 } else { 402 /* set ATTR_KILL_* bits and let VFS handle it */ 403 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID); 404 } 405 } 406 407 /* Change the attributes. */ 408 409 iap->ia_valid |= ATTR_CTIME; 410 411 err = nfserr_notsync; 412 if (!check_guard || guardtime == inode->i_ctime.tv_sec) { 413 fh_lock(fhp); 414 host_err = notify_change(dentry, iap); 415 err = nfserrno(host_err); 416 fh_unlock(fhp); 417 } 418 if (size_change) 419 put_write_access(inode); 420 if (!err) 421 if (EX_ISSYNC(fhp->fh_export)) 422 write_inode_now(inode, 1); 423 out: 424 return err; 425 426 out_nfserr: 427 err = nfserrno(host_err); 428 goto out; 429 } 430 431 #if defined(CONFIG_NFSD_V2_ACL) || \ 432 defined(CONFIG_NFSD_V3_ACL) || \ 433 defined(CONFIG_NFSD_V4) 434 static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf) 435 { 436 ssize_t buflen; 437 ssize_t ret; 438 439 buflen = vfs_getxattr(dentry, key, NULL, 0); 440 if (buflen <= 0) 441 return buflen; 442 443 *buf = kmalloc(buflen, GFP_KERNEL); 444 if (!*buf) 445 return -ENOMEM; 446 447 ret = vfs_getxattr(dentry, key, *buf, buflen); 448 if (ret < 0) 449 kfree(*buf); 450 return ret; 451 } 452 #endif 453 454 #if defined(CONFIG_NFSD_V4) 455 static int 456 set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key) 457 { 458 int len; 459 size_t buflen; 460 char *buf = NULL; 461 int error = 0; 462 463 buflen = posix_acl_xattr_size(pacl->a_count); 464 buf = kmalloc(buflen, GFP_KERNEL); 465 error = -ENOMEM; 466 if (buf == NULL) 467 goto out; 468 469 len = posix_acl_to_xattr(pacl, buf, buflen); 470 if (len < 0) { 471 error = len; 472 goto out; 473 } 474 475 error = vfs_setxattr(dentry, key, buf, len, 0); 476 out: 477 kfree(buf); 478 return error; 479 } 480 481 __be32 482 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, 483 struct nfs4_acl *acl) 484 { 485 __be32 error; 486 int host_error; 487 struct dentry *dentry; 488 struct inode *inode; 489 struct posix_acl *pacl = NULL, *dpacl = NULL; 490 unsigned int flags = 0; 491 492 /* Get inode */ 493 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); 494 if (error) 495 return error; 496 497 dentry = fhp->fh_dentry; 498 inode = dentry->d_inode; 499 if (S_ISDIR(inode->i_mode)) 500 flags = NFS4_ACL_DIR; 501 502 host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); 503 if (host_error == -EINVAL) { 504 return nfserr_attrnotsupp; 505 } else if (host_error < 0) 506 goto out_nfserr; 507 508 host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); 509 if (host_error < 0) 510 goto out_release; 511 512 if (S_ISDIR(inode->i_mode)) 513 host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); 514 515 out_release: 516 posix_acl_release(pacl); 517 posix_acl_release(dpacl); 518 out_nfserr: 519 if (host_error == -EOPNOTSUPP) 520 return nfserr_attrnotsupp; 521 else 522 return nfserrno(host_error); 523 } 524 525 static struct posix_acl * 526 _get_posix_acl(struct dentry *dentry, char *key) 527 { 528 void *buf = NULL; 529 struct posix_acl *pacl = NULL; 530 int buflen; 531 532 buflen = nfsd_getxattr(dentry, key, &buf); 533 if (!buflen) 534 buflen = -ENODATA; 535 if (buflen <= 0) 536 return ERR_PTR(buflen); 537 538 pacl = posix_acl_from_xattr(buf, buflen); 539 kfree(buf); 540 return pacl; 541 } 542 543 int 544 nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl) 545 { 546 struct inode *inode = dentry->d_inode; 547 int error = 0; 548 struct posix_acl *pacl = NULL, *dpacl = NULL; 549 unsigned int flags = 0; 550 551 pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS); 552 if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA) 553 pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); 554 if (IS_ERR(pacl)) { 555 error = PTR_ERR(pacl); 556 pacl = NULL; 557 goto out; 558 } 559 560 if (S_ISDIR(inode->i_mode)) { 561 dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT); 562 if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA) 563 dpacl = NULL; 564 else if (IS_ERR(dpacl)) { 565 error = PTR_ERR(dpacl); 566 dpacl = NULL; 567 goto out; 568 } 569 flags = NFS4_ACL_DIR; 570 } 571 572 *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags); 573 if (IS_ERR(*acl)) { 574 error = PTR_ERR(*acl); 575 *acl = NULL; 576 } 577 out: 578 posix_acl_release(pacl); 579 posix_acl_release(dpacl); 580 return error; 581 } 582 583 #endif /* defined(CONFIG_NFS_V4) */ 584 585 #ifdef CONFIG_NFSD_V3 586 /* 587 * Check server access rights to a file system object 588 */ 589 struct accessmap { 590 u32 access; 591 int how; 592 }; 593 static struct accessmap nfs3_regaccess[] = { 594 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 595 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 596 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, 597 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, 598 599 { 0, 0 } 600 }; 601 602 static struct accessmap nfs3_diraccess[] = { 603 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 604 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, 605 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, 606 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, 607 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, 608 609 { 0, 0 } 610 }; 611 612 static struct accessmap nfs3_anyaccess[] = { 613 /* Some clients - Solaris 2.6 at least, make an access call 614 * to the server to check for access for things like /dev/null 615 * (which really, the server doesn't care about). So 616 * We provide simple access checking for them, looking 617 * mainly at mode bits, and we make sure to ignore read-only 618 * filesystem checks 619 */ 620 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 621 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 622 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 623 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 624 625 { 0, 0 } 626 }; 627 628 __be32 629 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 630 { 631 struct accessmap *map; 632 struct svc_export *export; 633 struct dentry *dentry; 634 u32 query, result = 0, sresult = 0; 635 __be32 error; 636 637 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP); 638 if (error) 639 goto out; 640 641 export = fhp->fh_export; 642 dentry = fhp->fh_dentry; 643 644 if (S_ISREG(dentry->d_inode->i_mode)) 645 map = nfs3_regaccess; 646 else if (S_ISDIR(dentry->d_inode->i_mode)) 647 map = nfs3_diraccess; 648 else 649 map = nfs3_anyaccess; 650 651 652 query = *access; 653 for (; map->access; map++) { 654 if (map->access & query) { 655 __be32 err2; 656 657 sresult |= map->access; 658 659 err2 = nfsd_permission(rqstp, export, dentry, map->how); 660 switch (err2) { 661 case nfs_ok: 662 result |= map->access; 663 break; 664 665 /* the following error codes just mean the access was not allowed, 666 * rather than an error occurred */ 667 case nfserr_rofs: 668 case nfserr_acces: 669 case nfserr_perm: 670 /* simply don't "or" in the access bit. */ 671 break; 672 default: 673 error = err2; 674 goto out; 675 } 676 } 677 } 678 *access = result; 679 if (supported) 680 *supported = sresult; 681 682 out: 683 return error; 684 } 685 #endif /* CONFIG_NFSD_V3 */ 686 687 688 689 /* 690 * Open an existing file or directory. 691 * The access argument indicates the type of open (read/write/lock) 692 * N.B. After this call fhp needs an fh_put 693 */ 694 __be32 695 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 696 int access, struct file **filp) 697 { 698 struct dentry *dentry; 699 struct inode *inode; 700 int flags = O_RDONLY|O_LARGEFILE; 701 __be32 err; 702 int host_err; 703 704 validate_process_creds(); 705 706 /* 707 * If we get here, then the client has already done an "open", 708 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 709 * in case a chmod has now revoked permission. 710 */ 711 err = fh_verify(rqstp, fhp, type, access | NFSD_MAY_OWNER_OVERRIDE); 712 if (err) 713 goto out; 714 715 dentry = fhp->fh_dentry; 716 inode = dentry->d_inode; 717 718 /* Disallow write access to files with the append-only bit set 719 * or any access when mandatory locking enabled 720 */ 721 err = nfserr_perm; 722 if (IS_APPEND(inode) && (access & NFSD_MAY_WRITE)) 723 goto out; 724 /* 725 * We must ignore files (but only files) which might have mandatory 726 * locks on them because there is no way to know if the accesser has 727 * the lock. 728 */ 729 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode)) 730 goto out; 731 732 if (!inode->i_fop) 733 goto out; 734 735 /* 736 * Check to see if there are any leases on this file. 737 * This may block while leases are broken. 738 */ 739 host_err = break_lease(inode, O_NONBLOCK | ((access & NFSD_MAY_WRITE) ? FMODE_WRITE : 0)); 740 if (host_err == -EWOULDBLOCK) 741 host_err = -ETIMEDOUT; 742 if (host_err) /* NOMEM or WOULDBLOCK */ 743 goto out_nfserr; 744 745 if (access & NFSD_MAY_WRITE) { 746 if (access & NFSD_MAY_READ) 747 flags = O_RDWR|O_LARGEFILE; 748 else 749 flags = O_WRONLY|O_LARGEFILE; 750 751 vfs_dq_init(inode); 752 } 753 *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_path.mnt), 754 flags, current_cred()); 755 if (IS_ERR(*filp)) 756 host_err = PTR_ERR(*filp); 757 else 758 ima_counts_get(*filp); 759 out_nfserr: 760 err = nfserrno(host_err); 761 out: 762 validate_process_creds(); 763 return err; 764 } 765 766 /* 767 * Close a file. 768 */ 769 void 770 nfsd_close(struct file *filp) 771 { 772 fput(filp); 773 } 774 775 /* 776 * Sync a file 777 * As this calls fsync (not fdatasync) there is no need for a write_inode 778 * after it. 779 */ 780 static inline int nfsd_dosync(struct file *filp, struct dentry *dp, 781 const struct file_operations *fop) 782 { 783 struct inode *inode = dp->d_inode; 784 int (*fsync) (struct file *, struct dentry *, int); 785 int err; 786 787 err = filemap_fdatawrite(inode->i_mapping); 788 if (err == 0 && fop && (fsync = fop->fsync)) 789 err = fsync(filp, dp, 0); 790 if (err == 0) 791 err = filemap_fdatawait(inode->i_mapping); 792 793 return err; 794 } 795 796 static int 797 nfsd_sync(struct file *filp) 798 { 799 int err; 800 struct inode *inode = filp->f_path.dentry->d_inode; 801 dprintk("nfsd: sync file %s\n", filp->f_path.dentry->d_name.name); 802 mutex_lock(&inode->i_mutex); 803 err=nfsd_dosync(filp, filp->f_path.dentry, filp->f_op); 804 mutex_unlock(&inode->i_mutex); 805 806 return err; 807 } 808 809 int 810 nfsd_sync_dir(struct dentry *dp) 811 { 812 return nfsd_dosync(NULL, dp, dp->d_inode->i_fop); 813 } 814 815 /* 816 * Obtain the readahead parameters for the file 817 * specified by (dev, ino). 818 */ 819 820 static inline struct raparms * 821 nfsd_get_raparms(dev_t dev, ino_t ino) 822 { 823 struct raparms *ra, **rap, **frap = NULL; 824 int depth = 0; 825 unsigned int hash; 826 struct raparm_hbucket *rab; 827 828 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK; 829 rab = &raparm_hash[hash]; 830 831 spin_lock(&rab->pb_lock); 832 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) { 833 if (ra->p_ino == ino && ra->p_dev == dev) 834 goto found; 835 depth++; 836 if (ra->p_count == 0) 837 frap = rap; 838 } 839 depth = nfsdstats.ra_size*11/10; 840 if (!frap) { 841 spin_unlock(&rab->pb_lock); 842 return NULL; 843 } 844 rap = frap; 845 ra = *frap; 846 ra->p_dev = dev; 847 ra->p_ino = ino; 848 ra->p_set = 0; 849 ra->p_hindex = hash; 850 found: 851 if (rap != &rab->pb_head) { 852 *rap = ra->p_next; 853 ra->p_next = rab->pb_head; 854 rab->pb_head = ra; 855 } 856 ra->p_count++; 857 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; 858 spin_unlock(&rab->pb_lock); 859 return ra; 860 } 861 862 /* 863 * Grab and keep cached pages associated with a file in the svc_rqst 864 * so that they can be passed to the network sendmsg/sendpage routines 865 * directly. They will be released after the sending has completed. 866 */ 867 static int 868 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 869 struct splice_desc *sd) 870 { 871 struct svc_rqst *rqstp = sd->u.data; 872 struct page **pp = rqstp->rq_respages + rqstp->rq_resused; 873 struct page *page = buf->page; 874 size_t size; 875 int ret; 876 877 ret = buf->ops->confirm(pipe, buf); 878 if (unlikely(ret)) 879 return ret; 880 881 size = sd->len; 882 883 if (rqstp->rq_res.page_len == 0) { 884 get_page(page); 885 put_page(*pp); 886 *pp = page; 887 rqstp->rq_resused++; 888 rqstp->rq_res.page_base = buf->offset; 889 rqstp->rq_res.page_len = size; 890 } else if (page != pp[-1]) { 891 get_page(page); 892 if (*pp) 893 put_page(*pp); 894 *pp = page; 895 rqstp->rq_resused++; 896 rqstp->rq_res.page_len += size; 897 } else 898 rqstp->rq_res.page_len += size; 899 900 return size; 901 } 902 903 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, 904 struct splice_desc *sd) 905 { 906 return __splice_from_pipe(pipe, sd, nfsd_splice_actor); 907 } 908 909 static inline int svc_msnfs(struct svc_fh *ffhp) 910 { 911 #ifdef MSNFS 912 return (ffhp->fh_export->ex_flags & NFSEXP_MSNFS); 913 #else 914 return 0; 915 #endif 916 } 917 918 static __be32 919 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 920 loff_t offset, struct kvec *vec, int vlen, unsigned long *count) 921 { 922 struct inode *inode; 923 struct raparms *ra; 924 mm_segment_t oldfs; 925 __be32 err; 926 int host_err; 927 928 err = nfserr_perm; 929 inode = file->f_path.dentry->d_inode; 930 931 if (svc_msnfs(fhp) && !lock_may_read(inode, offset, *count)) 932 goto out; 933 934 /* Get readahead parameters */ 935 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); 936 937 if (ra && ra->p_set) 938 file->f_ra = ra->p_ra; 939 940 if (file->f_op->splice_read && rqstp->rq_splice_ok) { 941 struct splice_desc sd = { 942 .len = 0, 943 .total_len = *count, 944 .pos = offset, 945 .u.data = rqstp, 946 }; 947 948 rqstp->rq_resused = 1; 949 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); 950 } else { 951 oldfs = get_fs(); 952 set_fs(KERNEL_DS); 953 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); 954 set_fs(oldfs); 955 } 956 957 /* Write back readahead params */ 958 if (ra) { 959 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex]; 960 spin_lock(&rab->pb_lock); 961 ra->p_ra = file->f_ra; 962 ra->p_set = 1; 963 ra->p_count--; 964 spin_unlock(&rab->pb_lock); 965 } 966 967 if (host_err >= 0) { 968 nfsdstats.io_read += host_err; 969 *count = host_err; 970 err = 0; 971 fsnotify_access(file->f_path.dentry); 972 } else 973 err = nfserrno(host_err); 974 out: 975 return err; 976 } 977 978 static void kill_suid(struct dentry *dentry) 979 { 980 struct iattr ia; 981 ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; 982 983 mutex_lock(&dentry->d_inode->i_mutex); 984 notify_change(dentry, &ia); 985 mutex_unlock(&dentry->d_inode->i_mutex); 986 } 987 988 /* 989 * Gathered writes: If another process is currently writing to the file, 990 * there's a high chance this is another nfsd (triggered by a bulk write 991 * from a client's biod). Rather than syncing the file with each write 992 * request, we sleep for 10 msec. 993 * 994 * I don't know if this roughly approximates C. Juszak's idea of 995 * gathered writes, but it's a nice and simple solution (IMHO), and it 996 * seems to work:-) 997 * 998 * Note: we do this only in the NFSv2 case, since v3 and higher have a 999 * better tool (separate unstable writes and commits) for solving this 1000 * problem. 1001 */ 1002 static int wait_for_concurrent_writes(struct file *file) 1003 { 1004 struct inode *inode = file->f_path.dentry->d_inode; 1005 static ino_t last_ino; 1006 static dev_t last_dev; 1007 int err = 0; 1008 1009 if (atomic_read(&inode->i_writecount) > 1 1010 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 1011 dprintk("nfsd: write defer %d\n", task_pid_nr(current)); 1012 msleep(10); 1013 dprintk("nfsd: write resume %d\n", task_pid_nr(current)); 1014 } 1015 1016 if (inode->i_state & I_DIRTY) { 1017 dprintk("nfsd: write sync %d\n", task_pid_nr(current)); 1018 err = nfsd_sync(file); 1019 } 1020 last_ino = inode->i_ino; 1021 last_dev = inode->i_sb->s_dev; 1022 return err; 1023 } 1024 1025 static __be32 1026 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1027 loff_t offset, struct kvec *vec, int vlen, 1028 unsigned long *cnt, int *stablep) 1029 { 1030 struct svc_export *exp; 1031 struct dentry *dentry; 1032 struct inode *inode; 1033 mm_segment_t oldfs; 1034 __be32 err = 0; 1035 int host_err; 1036 int stable = *stablep; 1037 int use_wgather; 1038 1039 #ifdef MSNFS 1040 err = nfserr_perm; 1041 1042 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1043 (!lock_may_write(file->f_path.dentry->d_inode, offset, *cnt))) 1044 goto out; 1045 #endif 1046 1047 dentry = file->f_path.dentry; 1048 inode = dentry->d_inode; 1049 exp = fhp->fh_export; 1050 1051 /* 1052 * Request sync writes if 1053 * - the sync export option has been set, or 1054 * - the client requested O_SYNC behavior (NFSv3 feature). 1055 * - The file system doesn't support fsync(). 1056 * When NFSv2 gathered writes have been configured for this volume, 1057 * flushing the data to disk is handled separately below. 1058 */ 1059 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); 1060 1061 if (!file->f_op->fsync) {/* COMMIT3 cannot work */ 1062 stable = 2; 1063 *stablep = 2; /* FILE_SYNC */ 1064 } 1065 1066 if (!EX_ISSYNC(exp)) 1067 stable = 0; 1068 if (stable && !use_wgather) { 1069 spin_lock(&file->f_lock); 1070 file->f_flags |= O_SYNC; 1071 spin_unlock(&file->f_lock); 1072 } 1073 1074 /* Write the data. */ 1075 oldfs = get_fs(); set_fs(KERNEL_DS); 1076 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); 1077 set_fs(oldfs); 1078 if (host_err < 0) 1079 goto out_nfserr; 1080 *cnt = host_err; 1081 nfsdstats.io_write += host_err; 1082 fsnotify_modify(file->f_path.dentry); 1083 1084 /* clear setuid/setgid flag after write */ 1085 if (inode->i_mode & (S_ISUID | S_ISGID)) 1086 kill_suid(dentry); 1087 1088 if (stable && use_wgather) 1089 host_err = wait_for_concurrent_writes(file); 1090 1091 out_nfserr: 1092 dprintk("nfsd: write complete host_err=%d\n", host_err); 1093 if (host_err >= 0) 1094 err = 0; 1095 else 1096 err = nfserrno(host_err); 1097 out: 1098 return err; 1099 } 1100 1101 /* 1102 * Read data from a file. count must contain the requested read count 1103 * on entry. On return, *count contains the number of bytes actually read. 1104 * N.B. After this call fhp needs an fh_put 1105 */ 1106 __be32 1107 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1108 loff_t offset, struct kvec *vec, int vlen, 1109 unsigned long *count) 1110 { 1111 __be32 err; 1112 1113 if (file) { 1114 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1115 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE); 1116 if (err) 1117 goto out; 1118 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1119 } else { 1120 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); 1121 if (err) 1122 goto out; 1123 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 1124 nfsd_close(file); 1125 } 1126 out: 1127 return err; 1128 } 1129 1130 /* 1131 * Write data to a file. 1132 * The stable flag requests synchronous writes. 1133 * N.B. After this call fhp needs an fh_put 1134 */ 1135 __be32 1136 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 1137 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, 1138 int *stablep) 1139 { 1140 __be32 err = 0; 1141 1142 if (file) { 1143 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 1144 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE); 1145 if (err) 1146 goto out; 1147 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, 1148 stablep); 1149 } else { 1150 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); 1151 if (err) 1152 goto out; 1153 1154 if (cnt) 1155 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, 1156 cnt, stablep); 1157 nfsd_close(file); 1158 } 1159 out: 1160 return err; 1161 } 1162 1163 #ifdef CONFIG_NFSD_V3 1164 /* 1165 * Commit all pending writes to stable storage. 1166 * Strictly speaking, we could sync just the indicated file region here, 1167 * but there's currently no way we can ask the VFS to do so. 1168 * 1169 * Unfortunately we cannot lock the file to make sure we return full WCC 1170 * data to the client, as locking happens lower down in the filesystem. 1171 */ 1172 __be32 1173 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1174 loff_t offset, unsigned long count) 1175 { 1176 struct file *file; 1177 __be32 err; 1178 1179 if ((u64)count > ~(u64)offset) 1180 return nfserr_inval; 1181 1182 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); 1183 if (err) 1184 return err; 1185 if (EX_ISSYNC(fhp->fh_export)) { 1186 if (file->f_op && file->f_op->fsync) { 1187 err = nfserrno(nfsd_sync(file)); 1188 } else { 1189 err = nfserr_notsupp; 1190 } 1191 } 1192 1193 nfsd_close(file); 1194 return err; 1195 } 1196 #endif /* CONFIG_NFSD_V3 */ 1197 1198 static __be32 1199 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp, 1200 struct iattr *iap) 1201 { 1202 /* 1203 * Mode has already been set earlier in create: 1204 */ 1205 iap->ia_valid &= ~ATTR_MODE; 1206 /* 1207 * Setting uid/gid works only for root. Irix appears to 1208 * send along the gid on create when it tries to implement 1209 * setgid directories via NFS: 1210 */ 1211 if (current_fsuid() != 0) 1212 iap->ia_valid &= ~(ATTR_UID|ATTR_GID); 1213 if (iap->ia_valid) 1214 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 1215 return 0; 1216 } 1217 1218 /* HPUX client sometimes creates a file in mode 000, and sets size to 0. 1219 * setting size to 0 may fail for some specific file systems by the permission 1220 * checking which requires WRITE permission but the mode is 000. 1221 * we ignore the resizing(to 0) on the just new created file, since the size is 1222 * 0 after file created. 1223 * 1224 * call this only after vfs_create() is called. 1225 * */ 1226 static void 1227 nfsd_check_ignore_resizing(struct iattr *iap) 1228 { 1229 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) 1230 iap->ia_valid &= ~ATTR_SIZE; 1231 } 1232 1233 /* 1234 * Create a file (regular, directory, device, fifo); UNIX sockets 1235 * not yet implemented. 1236 * If the response fh has been verified, the parent directory should 1237 * already be locked. Note that the parent directory is left locked. 1238 * 1239 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1240 */ 1241 __be32 1242 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1243 char *fname, int flen, struct iattr *iap, 1244 int type, dev_t rdev, struct svc_fh *resfhp) 1245 { 1246 struct dentry *dentry, *dchild = NULL; 1247 struct inode *dirp; 1248 __be32 err; 1249 __be32 err2; 1250 int host_err; 1251 1252 err = nfserr_perm; 1253 if (!flen) 1254 goto out; 1255 err = nfserr_exist; 1256 if (isdotent(fname, flen)) 1257 goto out; 1258 1259 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1260 if (err) 1261 goto out; 1262 1263 dentry = fhp->fh_dentry; 1264 dirp = dentry->d_inode; 1265 1266 err = nfserr_notdir; 1267 if (!dirp->i_op->lookup) 1268 goto out; 1269 /* 1270 * Check whether the response file handle has been verified yet. 1271 * If it has, the parent directory should already be locked. 1272 */ 1273 if (!resfhp->fh_dentry) { 1274 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ 1275 fh_lock_nested(fhp, I_MUTEX_PARENT); 1276 dchild = lookup_one_len(fname, dentry, flen); 1277 host_err = PTR_ERR(dchild); 1278 if (IS_ERR(dchild)) 1279 goto out_nfserr; 1280 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1281 if (err) 1282 goto out; 1283 } else { 1284 /* called from nfsd_proc_create */ 1285 dchild = dget(resfhp->fh_dentry); 1286 if (!fhp->fh_locked) { 1287 /* not actually possible */ 1288 printk(KERN_ERR 1289 "nfsd_create: parent %s/%s not locked!\n", 1290 dentry->d_parent->d_name.name, 1291 dentry->d_name.name); 1292 err = nfserr_io; 1293 goto out; 1294 } 1295 } 1296 /* 1297 * Make sure the child dentry is still negative ... 1298 */ 1299 err = nfserr_exist; 1300 if (dchild->d_inode) { 1301 dprintk("nfsd_create: dentry %s/%s not negative!\n", 1302 dentry->d_name.name, dchild->d_name.name); 1303 goto out; 1304 } 1305 1306 if (!(iap->ia_valid & ATTR_MODE)) 1307 iap->ia_mode = 0; 1308 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1309 1310 err = nfserr_inval; 1311 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) { 1312 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", 1313 type); 1314 goto out; 1315 } 1316 1317 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1318 if (host_err) 1319 goto out_nfserr; 1320 1321 /* 1322 * Get the dir op function pointer. 1323 */ 1324 err = 0; 1325 switch (type) { 1326 case S_IFREG: 1327 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1328 if (!host_err) 1329 nfsd_check_ignore_resizing(iap); 1330 break; 1331 case S_IFDIR: 1332 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1333 break; 1334 case S_IFCHR: 1335 case S_IFBLK: 1336 case S_IFIFO: 1337 case S_IFSOCK: 1338 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1339 break; 1340 } 1341 if (host_err < 0) { 1342 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1343 goto out_nfserr; 1344 } 1345 1346 if (EX_ISSYNC(fhp->fh_export)) { 1347 err = nfserrno(nfsd_sync_dir(dentry)); 1348 write_inode_now(dchild->d_inode, 1); 1349 } 1350 1351 err2 = nfsd_create_setattr(rqstp, resfhp, iap); 1352 if (err2) 1353 err = err2; 1354 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1355 /* 1356 * Update the file handle to get the new inode info. 1357 */ 1358 if (!err) 1359 err = fh_update(resfhp); 1360 out: 1361 if (dchild && !IS_ERR(dchild)) 1362 dput(dchild); 1363 return err; 1364 1365 out_nfserr: 1366 err = nfserrno(host_err); 1367 goto out; 1368 } 1369 1370 #ifdef CONFIG_NFSD_V3 1371 /* 1372 * NFSv3 version of nfsd_create 1373 */ 1374 __be32 1375 nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, 1376 char *fname, int flen, struct iattr *iap, 1377 struct svc_fh *resfhp, int createmode, u32 *verifier, 1378 int *truncp, int *created) 1379 { 1380 struct dentry *dentry, *dchild = NULL; 1381 struct inode *dirp; 1382 __be32 err; 1383 __be32 err2; 1384 int host_err; 1385 __u32 v_mtime=0, v_atime=0; 1386 1387 err = nfserr_perm; 1388 if (!flen) 1389 goto out; 1390 err = nfserr_exist; 1391 if (isdotent(fname, flen)) 1392 goto out; 1393 if (!(iap->ia_valid & ATTR_MODE)) 1394 iap->ia_mode = 0; 1395 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1396 if (err) 1397 goto out; 1398 1399 dentry = fhp->fh_dentry; 1400 dirp = dentry->d_inode; 1401 1402 /* Get all the sanity checks out of the way before 1403 * we lock the parent. */ 1404 err = nfserr_notdir; 1405 if (!dirp->i_op->lookup) 1406 goto out; 1407 fh_lock_nested(fhp, I_MUTEX_PARENT); 1408 1409 /* 1410 * Compose the response file handle. 1411 */ 1412 dchild = lookup_one_len(fname, dentry, flen); 1413 host_err = PTR_ERR(dchild); 1414 if (IS_ERR(dchild)) 1415 goto out_nfserr; 1416 1417 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1418 if (err) 1419 goto out; 1420 1421 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1422 /* solaris7 gets confused (bugid 4218508) if these have 1423 * the high bit set, so just clear the high bits. If this is 1424 * ever changed to use different attrs for storing the 1425 * verifier, then do_open_lookup() will also need to be fixed 1426 * accordingly. 1427 */ 1428 v_mtime = verifier[0]&0x7fffffff; 1429 v_atime = verifier[1]&0x7fffffff; 1430 } 1431 1432 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1433 if (host_err) 1434 goto out_nfserr; 1435 if (dchild->d_inode) { 1436 err = 0; 1437 1438 switch (createmode) { 1439 case NFS3_CREATE_UNCHECKED: 1440 if (! S_ISREG(dchild->d_inode->i_mode)) 1441 err = nfserr_exist; 1442 else if (truncp) { 1443 /* in nfsv4, we need to treat this case a little 1444 * differently. we don't want to truncate the 1445 * file now; this would be wrong if the OPEN 1446 * fails for some other reason. furthermore, 1447 * if the size is nonzero, we should ignore it 1448 * according to spec! 1449 */ 1450 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1451 } 1452 else { 1453 iap->ia_valid &= ATTR_SIZE; 1454 goto set_attr; 1455 } 1456 break; 1457 case NFS3_CREATE_EXCLUSIVE: 1458 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime 1459 && dchild->d_inode->i_atime.tv_sec == v_atime 1460 && dchild->d_inode->i_size == 0 ) 1461 break; 1462 /* fallthru */ 1463 case NFS3_CREATE_GUARDED: 1464 err = nfserr_exist; 1465 } 1466 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1467 goto out; 1468 } 1469 1470 host_err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 1471 if (host_err < 0) { 1472 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1473 goto out_nfserr; 1474 } 1475 if (created) 1476 *created = 1; 1477 1478 if (EX_ISSYNC(fhp->fh_export)) { 1479 err = nfserrno(nfsd_sync_dir(dentry)); 1480 /* setattr will sync the child (or not) */ 1481 } 1482 1483 nfsd_check_ignore_resizing(iap); 1484 1485 if (createmode == NFS3_CREATE_EXCLUSIVE) { 1486 /* Cram the verifier into atime/mtime */ 1487 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1488 | ATTR_MTIME_SET|ATTR_ATIME_SET; 1489 /* XXX someone who knows this better please fix it for nsec */ 1490 iap->ia_mtime.tv_sec = v_mtime; 1491 iap->ia_atime.tv_sec = v_atime; 1492 iap->ia_mtime.tv_nsec = 0; 1493 iap->ia_atime.tv_nsec = 0; 1494 } 1495 1496 set_attr: 1497 err2 = nfsd_create_setattr(rqstp, resfhp, iap); 1498 if (err2) 1499 err = err2; 1500 1501 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1502 /* 1503 * Update the filehandle to get the new inode info. 1504 */ 1505 if (!err) 1506 err = fh_update(resfhp); 1507 1508 out: 1509 fh_unlock(fhp); 1510 if (dchild && !IS_ERR(dchild)) 1511 dput(dchild); 1512 return err; 1513 1514 out_nfserr: 1515 err = nfserrno(host_err); 1516 goto out; 1517 } 1518 #endif /* CONFIG_NFSD_V3 */ 1519 1520 /* 1521 * Read a symlink. On entry, *lenp must contain the maximum path length that 1522 * fits into the buffer. On return, it contains the true length. 1523 * N.B. After this call fhp needs an fh_put 1524 */ 1525 __be32 1526 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1527 { 1528 struct dentry *dentry; 1529 struct inode *inode; 1530 mm_segment_t oldfs; 1531 __be32 err; 1532 int host_err; 1533 1534 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); 1535 if (err) 1536 goto out; 1537 1538 dentry = fhp->fh_dentry; 1539 inode = dentry->d_inode; 1540 1541 err = nfserr_inval; 1542 if (!inode->i_op->readlink) 1543 goto out; 1544 1545 touch_atime(fhp->fh_export->ex_path.mnt, dentry); 1546 /* N.B. Why does this call need a get_fs()?? 1547 * Remove the set_fs and watch the fireworks:-) --okir 1548 */ 1549 1550 oldfs = get_fs(); set_fs(KERNEL_DS); 1551 host_err = inode->i_op->readlink(dentry, buf, *lenp); 1552 set_fs(oldfs); 1553 1554 if (host_err < 0) 1555 goto out_nfserr; 1556 *lenp = host_err; 1557 err = 0; 1558 out: 1559 return err; 1560 1561 out_nfserr: 1562 err = nfserrno(host_err); 1563 goto out; 1564 } 1565 1566 /* 1567 * Create a symlink and look up its inode 1568 * N.B. After this call _both_ fhp and resfhp need an fh_put 1569 */ 1570 __be32 1571 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1572 char *fname, int flen, 1573 char *path, int plen, 1574 struct svc_fh *resfhp, 1575 struct iattr *iap) 1576 { 1577 struct dentry *dentry, *dnew; 1578 __be32 err, cerr; 1579 int host_err; 1580 1581 err = nfserr_noent; 1582 if (!flen || !plen) 1583 goto out; 1584 err = nfserr_exist; 1585 if (isdotent(fname, flen)) 1586 goto out; 1587 1588 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1589 if (err) 1590 goto out; 1591 fh_lock(fhp); 1592 dentry = fhp->fh_dentry; 1593 dnew = lookup_one_len(fname, dentry, flen); 1594 host_err = PTR_ERR(dnew); 1595 if (IS_ERR(dnew)) 1596 goto out_nfserr; 1597 1598 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1599 if (host_err) 1600 goto out_nfserr; 1601 1602 if (unlikely(path[plen] != 0)) { 1603 char *path_alloced = kmalloc(plen+1, GFP_KERNEL); 1604 if (path_alloced == NULL) 1605 host_err = -ENOMEM; 1606 else { 1607 strncpy(path_alloced, path, plen); 1608 path_alloced[plen] = 0; 1609 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced); 1610 kfree(path_alloced); 1611 } 1612 } else 1613 host_err = vfs_symlink(dentry->d_inode, dnew, path); 1614 1615 if (!host_err) { 1616 if (EX_ISSYNC(fhp->fh_export)) 1617 host_err = nfsd_sync_dir(dentry); 1618 } 1619 err = nfserrno(host_err); 1620 fh_unlock(fhp); 1621 1622 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1623 1624 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1625 dput(dnew); 1626 if (err==0) err = cerr; 1627 out: 1628 return err; 1629 1630 out_nfserr: 1631 err = nfserrno(host_err); 1632 goto out; 1633 } 1634 1635 /* 1636 * Create a hardlink 1637 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1638 */ 1639 __be32 1640 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1641 char *name, int len, struct svc_fh *tfhp) 1642 { 1643 struct dentry *ddir, *dnew, *dold; 1644 struct inode *dirp, *dest; 1645 __be32 err; 1646 int host_err; 1647 1648 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); 1649 if (err) 1650 goto out; 1651 err = fh_verify(rqstp, tfhp, -S_IFDIR, NFSD_MAY_NOP); 1652 if (err) 1653 goto out; 1654 1655 err = nfserr_perm; 1656 if (!len) 1657 goto out; 1658 err = nfserr_exist; 1659 if (isdotent(name, len)) 1660 goto out; 1661 1662 fh_lock_nested(ffhp, I_MUTEX_PARENT); 1663 ddir = ffhp->fh_dentry; 1664 dirp = ddir->d_inode; 1665 1666 dnew = lookup_one_len(name, ddir, len); 1667 host_err = PTR_ERR(dnew); 1668 if (IS_ERR(dnew)) 1669 goto out_nfserr; 1670 1671 dold = tfhp->fh_dentry; 1672 dest = dold->d_inode; 1673 1674 host_err = mnt_want_write(tfhp->fh_export->ex_path.mnt); 1675 if (host_err) { 1676 err = nfserrno(host_err); 1677 goto out_dput; 1678 } 1679 host_err = vfs_link(dold, dirp, dnew); 1680 if (!host_err) { 1681 if (EX_ISSYNC(ffhp->fh_export)) { 1682 err = nfserrno(nfsd_sync_dir(ddir)); 1683 write_inode_now(dest, 1); 1684 } 1685 err = 0; 1686 } else { 1687 if (host_err == -EXDEV && rqstp->rq_vers == 2) 1688 err = nfserr_acces; 1689 else 1690 err = nfserrno(host_err); 1691 } 1692 mnt_drop_write(tfhp->fh_export->ex_path.mnt); 1693 out_dput: 1694 dput(dnew); 1695 out_unlock: 1696 fh_unlock(ffhp); 1697 out: 1698 return err; 1699 1700 out_nfserr: 1701 err = nfserrno(host_err); 1702 goto out_unlock; 1703 } 1704 1705 /* 1706 * Rename a file 1707 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1708 */ 1709 __be32 1710 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1711 struct svc_fh *tfhp, char *tname, int tlen) 1712 { 1713 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1714 struct inode *fdir, *tdir; 1715 __be32 err; 1716 int host_err; 1717 1718 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); 1719 if (err) 1720 goto out; 1721 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE); 1722 if (err) 1723 goto out; 1724 1725 fdentry = ffhp->fh_dentry; 1726 fdir = fdentry->d_inode; 1727 1728 tdentry = tfhp->fh_dentry; 1729 tdir = tdentry->d_inode; 1730 1731 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; 1732 if (ffhp->fh_export != tfhp->fh_export) 1733 goto out; 1734 1735 err = nfserr_perm; 1736 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1737 goto out; 1738 1739 /* cannot use fh_lock as we need deadlock protective ordering 1740 * so do it by hand */ 1741 trap = lock_rename(tdentry, fdentry); 1742 ffhp->fh_locked = tfhp->fh_locked = 1; 1743 fill_pre_wcc(ffhp); 1744 fill_pre_wcc(tfhp); 1745 1746 odentry = lookup_one_len(fname, fdentry, flen); 1747 host_err = PTR_ERR(odentry); 1748 if (IS_ERR(odentry)) 1749 goto out_nfserr; 1750 1751 host_err = -ENOENT; 1752 if (!odentry->d_inode) 1753 goto out_dput_old; 1754 host_err = -EINVAL; 1755 if (odentry == trap) 1756 goto out_dput_old; 1757 1758 ndentry = lookup_one_len(tname, tdentry, tlen); 1759 host_err = PTR_ERR(ndentry); 1760 if (IS_ERR(ndentry)) 1761 goto out_dput_old; 1762 host_err = -ENOTEMPTY; 1763 if (ndentry == trap) 1764 goto out_dput_new; 1765 1766 if (svc_msnfs(ffhp) && 1767 ((atomic_read(&odentry->d_count) > 1) 1768 || (atomic_read(&ndentry->d_count) > 1))) { 1769 host_err = -EPERM; 1770 goto out_dput_new; 1771 } 1772 1773 host_err = -EXDEV; 1774 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) 1775 goto out_dput_new; 1776 host_err = mnt_want_write(ffhp->fh_export->ex_path.mnt); 1777 if (host_err) 1778 goto out_dput_new; 1779 1780 host_err = vfs_rename(fdir, odentry, tdir, ndentry); 1781 if (!host_err && EX_ISSYNC(tfhp->fh_export)) { 1782 host_err = nfsd_sync_dir(tdentry); 1783 if (!host_err) 1784 host_err = nfsd_sync_dir(fdentry); 1785 } 1786 1787 mnt_drop_write(ffhp->fh_export->ex_path.mnt); 1788 1789 out_dput_new: 1790 dput(ndentry); 1791 out_dput_old: 1792 dput(odentry); 1793 out_nfserr: 1794 err = nfserrno(host_err); 1795 1796 /* we cannot reply on fh_unlock on the two filehandles, 1797 * as that would do the wrong thing if the two directories 1798 * were the same, so again we do it by hand 1799 */ 1800 fill_post_wcc(ffhp); 1801 fill_post_wcc(tfhp); 1802 unlock_rename(tdentry, fdentry); 1803 ffhp->fh_locked = tfhp->fh_locked = 0; 1804 1805 out: 1806 return err; 1807 } 1808 1809 /* 1810 * Unlink a file or directory 1811 * N.B. After this call fhp needs an fh_put 1812 */ 1813 __be32 1814 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1815 char *fname, int flen) 1816 { 1817 struct dentry *dentry, *rdentry; 1818 struct inode *dirp; 1819 __be32 err; 1820 int host_err; 1821 1822 err = nfserr_acces; 1823 if (!flen || isdotent(fname, flen)) 1824 goto out; 1825 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); 1826 if (err) 1827 goto out; 1828 1829 fh_lock_nested(fhp, I_MUTEX_PARENT); 1830 dentry = fhp->fh_dentry; 1831 dirp = dentry->d_inode; 1832 1833 rdentry = lookup_one_len(fname, dentry, flen); 1834 host_err = PTR_ERR(rdentry); 1835 if (IS_ERR(rdentry)) 1836 goto out_nfserr; 1837 1838 if (!rdentry->d_inode) { 1839 dput(rdentry); 1840 err = nfserr_noent; 1841 goto out; 1842 } 1843 1844 if (!type) 1845 type = rdentry->d_inode->i_mode & S_IFMT; 1846 1847 host_err = mnt_want_write(fhp->fh_export->ex_path.mnt); 1848 if (host_err) 1849 goto out_nfserr; 1850 1851 if (type != S_IFDIR) { /* It's UNLINK */ 1852 #ifdef MSNFS 1853 if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && 1854 (atomic_read(&rdentry->d_count) > 1)) { 1855 host_err = -EPERM; 1856 } else 1857 #endif 1858 host_err = vfs_unlink(dirp, rdentry); 1859 } else { /* It's RMDIR */ 1860 host_err = vfs_rmdir(dirp, rdentry); 1861 } 1862 1863 dput(rdentry); 1864 1865 if (host_err) 1866 goto out_drop; 1867 if (EX_ISSYNC(fhp->fh_export)) 1868 host_err = nfsd_sync_dir(dentry); 1869 1870 out_drop: 1871 mnt_drop_write(fhp->fh_export->ex_path.mnt); 1872 out_nfserr: 1873 err = nfserrno(host_err); 1874 out: 1875 return err; 1876 } 1877 1878 /* 1879 * We do this buffering because we must not call back into the file 1880 * system's ->lookup() method from the filldir callback. That may well 1881 * deadlock a number of file systems. 1882 * 1883 * This is based heavily on the implementation of same in XFS. 1884 */ 1885 struct buffered_dirent { 1886 u64 ino; 1887 loff_t offset; 1888 int namlen; 1889 unsigned int d_type; 1890 char name[]; 1891 }; 1892 1893 struct readdir_data { 1894 char *dirent; 1895 size_t used; 1896 int full; 1897 }; 1898 1899 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, 1900 loff_t offset, u64 ino, unsigned int d_type) 1901 { 1902 struct readdir_data *buf = __buf; 1903 struct buffered_dirent *de = (void *)(buf->dirent + buf->used); 1904 unsigned int reclen; 1905 1906 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); 1907 if (buf->used + reclen > PAGE_SIZE) { 1908 buf->full = 1; 1909 return -EINVAL; 1910 } 1911 1912 de->namlen = namlen; 1913 de->offset = offset; 1914 de->ino = ino; 1915 de->d_type = d_type; 1916 memcpy(de->name, name, namlen); 1917 buf->used += reclen; 1918 1919 return 0; 1920 } 1921 1922 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, 1923 struct readdir_cd *cdp, loff_t *offsetp) 1924 { 1925 struct readdir_data buf; 1926 struct buffered_dirent *de; 1927 int host_err; 1928 int size; 1929 loff_t offset; 1930 1931 buf.dirent = (void *)__get_free_page(GFP_KERNEL); 1932 if (!buf.dirent) 1933 return nfserrno(-ENOMEM); 1934 1935 offset = *offsetp; 1936 1937 while (1) { 1938 struct inode *dir_inode = file->f_path.dentry->d_inode; 1939 unsigned int reclen; 1940 1941 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1942 buf.used = 0; 1943 buf.full = 0; 1944 1945 host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf); 1946 if (buf.full) 1947 host_err = 0; 1948 1949 if (host_err < 0) 1950 break; 1951 1952 size = buf.used; 1953 1954 if (!size) 1955 break; 1956 1957 /* 1958 * Various filldir functions may end up calling back into 1959 * lookup_one_len() and the file system's ->lookup() method. 1960 * These expect i_mutex to be held, as it would within readdir. 1961 */ 1962 host_err = mutex_lock_killable(&dir_inode->i_mutex); 1963 if (host_err) 1964 break; 1965 1966 de = (struct buffered_dirent *)buf.dirent; 1967 while (size > 0) { 1968 offset = de->offset; 1969 1970 if (func(cdp, de->name, de->namlen, de->offset, 1971 de->ino, de->d_type)) 1972 break; 1973 1974 if (cdp->err != nfs_ok) 1975 break; 1976 1977 reclen = ALIGN(sizeof(*de) + de->namlen, 1978 sizeof(u64)); 1979 size -= reclen; 1980 de = (struct buffered_dirent *)((char *)de + reclen); 1981 } 1982 mutex_unlock(&dir_inode->i_mutex); 1983 if (size > 0) /* We bailed out early */ 1984 break; 1985 1986 offset = vfs_llseek(file, 0, SEEK_CUR); 1987 } 1988 1989 free_page((unsigned long)(buf.dirent)); 1990 1991 if (host_err) 1992 return nfserrno(host_err); 1993 1994 *offsetp = offset; 1995 return cdp->err; 1996 } 1997 1998 /* 1999 * Read entries from a directory. 2000 * The NFSv3/4 verifier we ignore for now. 2001 */ 2002 __be32 2003 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 2004 struct readdir_cd *cdp, filldir_t func) 2005 { 2006 __be32 err; 2007 struct file *file; 2008 loff_t offset = *offsetp; 2009 2010 err = nfsd_open(rqstp, fhp, S_IFDIR, NFSD_MAY_READ, &file); 2011 if (err) 2012 goto out; 2013 2014 offset = vfs_llseek(file, offset, 0); 2015 if (offset < 0) { 2016 err = nfserrno((int)offset); 2017 goto out_close; 2018 } 2019 2020 err = nfsd_buffered_readdir(file, func, cdp, offsetp); 2021 2022 if (err == nfserr_eof || err == nfserr_toosmall) 2023 err = nfs_ok; /* can still be found in ->err */ 2024 out_close: 2025 nfsd_close(file); 2026 out: 2027 return err; 2028 } 2029 2030 /* 2031 * Get file system stats 2032 * N.B. After this call fhp needs an fh_put 2033 */ 2034 __be32 2035 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) 2036 { 2037 __be32 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); 2038 if (!err && vfs_statfs(fhp->fh_dentry,stat)) 2039 err = nfserr_io; 2040 return err; 2041 } 2042 2043 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) 2044 { 2045 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; 2046 } 2047 2048 /* 2049 * Check for a user's access permissions to this inode. 2050 */ 2051 __be32 2052 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, 2053 struct dentry *dentry, int acc) 2054 { 2055 struct inode *inode = dentry->d_inode; 2056 struct path path; 2057 int err; 2058 2059 if (acc == NFSD_MAY_NOP) 2060 return 0; 2061 #if 0 2062 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 2063 acc, 2064 (acc & NFSD_MAY_READ)? " read" : "", 2065 (acc & NFSD_MAY_WRITE)? " write" : "", 2066 (acc & NFSD_MAY_EXEC)? " exec" : "", 2067 (acc & NFSD_MAY_SATTR)? " sattr" : "", 2068 (acc & NFSD_MAY_TRUNC)? " trunc" : "", 2069 (acc & NFSD_MAY_LOCK)? " lock" : "", 2070 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", 2071 inode->i_mode, 2072 IS_IMMUTABLE(inode)? " immut" : "", 2073 IS_APPEND(inode)? " append" : "", 2074 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); 2075 dprintk(" owner %d/%d user %d/%d\n", 2076 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); 2077 #endif 2078 2079 /* Normally we reject any write/sattr etc access on a read-only file 2080 * system. But if it is IRIX doing check on write-access for a 2081 * device special file, we ignore rofs. 2082 */ 2083 if (!(acc & NFSD_MAY_LOCAL_ACCESS)) 2084 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { 2085 if (exp_rdonly(rqstp, exp) || 2086 __mnt_is_readonly(exp->ex_path.mnt)) 2087 return nfserr_rofs; 2088 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) 2089 return nfserr_perm; 2090 } 2091 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) 2092 return nfserr_perm; 2093 2094 if (acc & NFSD_MAY_LOCK) { 2095 /* If we cannot rely on authentication in NLM requests, 2096 * just allow locks, otherwise require read permission, or 2097 * ownership 2098 */ 2099 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 2100 return 0; 2101 else 2102 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE; 2103 } 2104 /* 2105 * The file owner always gets access permission for accesses that 2106 * would normally be checked at open time. This is to make 2107 * file access work even when the client has done a fchmod(fd, 0). 2108 * 2109 * However, `cp foo bar' should fail nevertheless when bar is 2110 * readonly. A sensible way to do this might be to reject all 2111 * attempts to truncate a read-only file, because a creat() call 2112 * always implies file truncation. 2113 * ... but this isn't really fair. A process may reasonably call 2114 * ftruncate on an open file descriptor on a file with perm 000. 2115 * We must trust the client to do permission checking - using "ACCESS" 2116 * with NFSv3. 2117 */ 2118 if ((acc & NFSD_MAY_OWNER_OVERRIDE) && 2119 inode->i_uid == current_fsuid()) 2120 return 0; 2121 2122 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ 2123 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); 2124 2125 /* Allow read access to binaries even when mode 111 */ 2126 if (err == -EACCES && S_ISREG(inode->i_mode) && 2127 acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE)) 2128 err = inode_permission(inode, MAY_EXEC); 2129 if (err) 2130 goto nfsd_out; 2131 2132 /* Do integrity (permission) checking now, but defer incrementing 2133 * IMA counts to the actual file open. 2134 */ 2135 path.mnt = exp->ex_path.mnt; 2136 path.dentry = dentry; 2137 err = ima_path_check(&path, acc & (MAY_READ | MAY_WRITE | MAY_EXEC), 2138 IMA_COUNT_LEAVE); 2139 nfsd_out: 2140 return err? nfserrno(err) : 0; 2141 } 2142 2143 void 2144 nfsd_racache_shutdown(void) 2145 { 2146 struct raparms *raparm, *last_raparm; 2147 unsigned int i; 2148 2149 dprintk("nfsd: freeing readahead buffers.\n"); 2150 2151 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2152 raparm = raparm_hash[i].pb_head; 2153 while(raparm) { 2154 last_raparm = raparm; 2155 raparm = raparm->p_next; 2156 kfree(last_raparm); 2157 } 2158 raparm_hash[i].pb_head = NULL; 2159 } 2160 } 2161 /* 2162 * Initialize readahead param cache 2163 */ 2164 int 2165 nfsd_racache_init(int cache_size) 2166 { 2167 int i; 2168 int j = 0; 2169 int nperbucket; 2170 struct raparms **raparm = NULL; 2171 2172 2173 if (raparm_hash[0].pb_head) 2174 return 0; 2175 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE); 2176 if (nperbucket < 2) 2177 nperbucket = 2; 2178 cache_size = nperbucket * RAPARM_HASH_SIZE; 2179 2180 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); 2181 2182 for (i = 0; i < RAPARM_HASH_SIZE; i++) { 2183 spin_lock_init(&raparm_hash[i].pb_lock); 2184 2185 raparm = &raparm_hash[i].pb_head; 2186 for (j = 0; j < nperbucket; j++) { 2187 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL); 2188 if (!*raparm) 2189 goto out_nomem; 2190 raparm = &(*raparm)->p_next; 2191 } 2192 *raparm = NULL; 2193 } 2194 2195 nfsdstats.ra_size = cache_size; 2196 return 0; 2197 2198 out_nomem: 2199 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n"); 2200 nfsd_racache_shutdown(); 2201 return -ENOMEM; 2202 } 2203 2204 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) 2205 struct posix_acl * 2206 nfsd_get_posix_acl(struct svc_fh *fhp, int type) 2207 { 2208 struct inode *inode = fhp->fh_dentry->d_inode; 2209 char *name; 2210 void *value = NULL; 2211 ssize_t size; 2212 struct posix_acl *acl; 2213 2214 if (!IS_POSIXACL(inode)) 2215 return ERR_PTR(-EOPNOTSUPP); 2216 2217 switch (type) { 2218 case ACL_TYPE_ACCESS: 2219 name = POSIX_ACL_XATTR_ACCESS; 2220 break; 2221 case ACL_TYPE_DEFAULT: 2222 name = POSIX_ACL_XATTR_DEFAULT; 2223 break; 2224 default: 2225 return ERR_PTR(-EOPNOTSUPP); 2226 } 2227 2228 size = nfsd_getxattr(fhp->fh_dentry, name, &value); 2229 if (size < 0) 2230 return ERR_PTR(size); 2231 2232 acl = posix_acl_from_xattr(value, size); 2233 kfree(value); 2234 return acl; 2235 } 2236 2237 int 2238 nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) 2239 { 2240 struct inode *inode = fhp->fh_dentry->d_inode; 2241 char *name; 2242 void *value = NULL; 2243 size_t size; 2244 int error; 2245 2246 if (!IS_POSIXACL(inode) || 2247 !inode->i_op->setxattr || !inode->i_op->removexattr) 2248 return -EOPNOTSUPP; 2249 switch(type) { 2250 case ACL_TYPE_ACCESS: 2251 name = POSIX_ACL_XATTR_ACCESS; 2252 break; 2253 case ACL_TYPE_DEFAULT: 2254 name = POSIX_ACL_XATTR_DEFAULT; 2255 break; 2256 default: 2257 return -EOPNOTSUPP; 2258 } 2259 2260 if (acl && acl->a_count) { 2261 size = posix_acl_xattr_size(acl->a_count); 2262 value = kmalloc(size, GFP_KERNEL); 2263 if (!value) 2264 return -ENOMEM; 2265 error = posix_acl_to_xattr(acl, value, size); 2266 if (error < 0) 2267 goto getout; 2268 size = error; 2269 } else 2270 size = 0; 2271 2272 error = mnt_want_write(fhp->fh_export->ex_path.mnt); 2273 if (error) 2274 goto getout; 2275 if (size) 2276 error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); 2277 else { 2278 if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) 2279 error = 0; 2280 else { 2281 error = vfs_removexattr(fhp->fh_dentry, name); 2282 if (error == -ENODATA) 2283 error = 0; 2284 } 2285 } 2286 mnt_drop_write(fhp->fh_export->ex_path.mnt); 2287 2288 getout: 2289 kfree(value); 2290 return error; 2291 } 2292 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */ 2293