1 // SPDX-License-Identifier: GPL-2.0 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/falloc.h> 21 #include <linux/fcntl.h> 22 #include <linux/namei.h> 23 #include <linux/delay.h> 24 #include <linux/fsnotify.h> 25 #include <linux/posix_acl_xattr.h> 26 #include <linux/xattr.h> 27 #include <linux/jhash.h> 28 #include <linux/ima.h> 29 #include <linux/slab.h> 30 #include <linux/uaccess.h> 31 #include <linux/exportfs.h> 32 #include <linux/writeback.h> 33 #include <linux/security.h> 34 35 #ifdef CONFIG_NFSD_V3 36 #include "xdr3.h" 37 #endif /* CONFIG_NFSD_V3 */ 38 39 #ifdef CONFIG_NFSD_V4 40 #include "../internal.h" 41 #include "acl.h" 42 #include "idmap.h" 43 #endif /* CONFIG_NFSD_V4 */ 44 45 #include "nfsd.h" 46 #include "vfs.h" 47 #include "filecache.h" 48 #include "trace.h" 49 50 #define NFSDDBG_FACILITY NFSDDBG_FILEOP 51 52 /* 53 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 54 * a mount point. 55 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged, 56 * or nfs_ok having possibly changed *dpp and *expp 57 */ 58 int 59 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 60 struct svc_export **expp) 61 { 62 struct svc_export *exp = *expp, *exp2 = NULL; 63 struct dentry *dentry = *dpp; 64 struct path path = {.mnt = mntget(exp->ex_path.mnt), 65 .dentry = dget(dentry)}; 66 int err = 0; 67 68 err = follow_down(&path); 69 if (err < 0) 70 goto out; 71 if (path.mnt == exp->ex_path.mnt && path.dentry == dentry && 72 nfsd_mountpoint(dentry, exp) == 2) { 73 /* This is only a mountpoint in some other namespace */ 74 path_put(&path); 75 goto out; 76 } 77 78 exp2 = rqst_exp_get_by_name(rqstp, &path); 79 if (IS_ERR(exp2)) { 80 err = PTR_ERR(exp2); 81 /* 82 * We normally allow NFS clients to continue 83 * "underneath" a mountpoint that is not exported. 84 * The exception is V4ROOT, where no traversal is ever 85 * allowed without an explicit export of the new 86 * directory. 87 */ 88 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT)) 89 err = 0; 90 path_put(&path); 91 goto out; 92 } 93 if (nfsd_v4client(rqstp) || 94 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) { 95 /* successfully crossed mount point */ 96 /* 97 * This is subtle: path.dentry is *not* on path.mnt 98 * at this point. The only reason we are safe is that 99 * original mnt is pinned down by exp, so we should 100 * put path *before* putting exp 101 */ 102 *dpp = path.dentry; 103 path.dentry = dentry; 104 *expp = exp2; 105 exp2 = exp; 106 } 107 path_put(&path); 108 exp_put(exp2); 109 out: 110 return err; 111 } 112 113 static void follow_to_parent(struct path *path) 114 { 115 struct dentry *dp; 116 117 while (path->dentry == path->mnt->mnt_root && follow_up(path)) 118 ; 119 dp = dget_parent(path->dentry); 120 dput(path->dentry); 121 path->dentry = dp; 122 } 123 124 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp) 125 { 126 struct svc_export *exp2; 127 struct path path = {.mnt = mntget((*exp)->ex_path.mnt), 128 .dentry = dget(dparent)}; 129 130 follow_to_parent(&path); 131 132 exp2 = rqst_exp_parent(rqstp, &path); 133 if (PTR_ERR(exp2) == -ENOENT) { 134 *dentryp = dget(dparent); 135 } else if (IS_ERR(exp2)) { 136 path_put(&path); 137 return PTR_ERR(exp2); 138 } else { 139 *dentryp = dget(path.dentry); 140 exp_put(*exp); 141 *exp = exp2; 142 } 143 path_put(&path); 144 return 0; 145 } 146 147 /* 148 * For nfsd purposes, we treat V4ROOT exports as though there was an 149 * export at *every* directory. 150 * We return: 151 * '1' if this dentry *must* be an export point, 152 * '2' if it might be, if there is really a mount here, and 153 * '0' if there is no chance of an export point here. 154 */ 155 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) 156 { 157 if (!d_inode(dentry)) 158 return 0; 159 if (exp->ex_flags & NFSEXP_V4ROOT) 160 return 1; 161 if (nfsd4_is_junction(dentry)) 162 return 1; 163 if (d_mountpoint(dentry)) 164 /* 165 * Might only be a mountpoint in a different namespace, 166 * but we need to check. 167 */ 168 return 2; 169 return 0; 170 } 171 172 __be32 173 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, 174 const char *name, unsigned int len, 175 struct svc_export **exp_ret, struct dentry **dentry_ret) 176 { 177 struct svc_export *exp; 178 struct dentry *dparent; 179 struct dentry *dentry; 180 int host_err; 181 182 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); 183 184 dparent = fhp->fh_dentry; 185 exp = exp_get(fhp->fh_export); 186 187 /* Lookup the name, but don't follow links */ 188 if (isdotent(name, len)) { 189 if (len==1) 190 dentry = dget(dparent); 191 else if (dparent != exp->ex_path.dentry) 192 dentry = dget_parent(dparent); 193 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp)) 194 dentry = dget(dparent); /* .. == . just like at / */ 195 else { 196 /* checking mountpoint crossing is very different when stepping up */ 197 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry); 198 if (host_err) 199 goto out_nfserr; 200 } 201 } else { 202 /* 203 * In the nfsd4_open() case, this may be held across 204 * subsequent open and delegation acquisition which may 205 * need to take the child's i_mutex: 206 */ 207 fh_lock_nested(fhp, I_MUTEX_PARENT); 208 dentry = lookup_one_len(name, dparent, len); 209 host_err = PTR_ERR(dentry); 210 if (IS_ERR(dentry)) 211 goto out_nfserr; 212 if (nfsd_mountpoint(dentry, exp)) { 213 /* 214 * We don't need the i_mutex after all. It's 215 * still possible we could open this (regular 216 * files can be mountpoints too), but the 217 * i_mutex is just there to prevent renames of 218 * something that we might be about to delegate, 219 * and a mountpoint won't be renamed: 220 */ 221 fh_unlock(fhp); 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 = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); 258 if (err) 259 return err; 260 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry); 261 if (err) 262 return err; 263 err = check_nfsd_access(exp, rqstp); 264 if (err) 265 goto out; 266 /* 267 * Note: we compose the file handle now, but as the 268 * dentry may be negative, it may need to be updated. 269 */ 270 err = fh_compose(resfh, exp, dentry, fhp); 271 if (!err && d_really_is_negative(dentry)) 272 err = nfserr_noent; 273 out: 274 dput(dentry); 275 exp_put(exp); 276 return err; 277 } 278 279 /* 280 * Commit metadata changes to stable storage. 281 */ 282 static int 283 commit_inode_metadata(struct inode *inode) 284 { 285 const struct export_operations *export_ops = inode->i_sb->s_export_op; 286 287 if (export_ops->commit_metadata) 288 return export_ops->commit_metadata(inode); 289 return sync_inode_metadata(inode, 1); 290 } 291 292 static int 293 commit_metadata(struct svc_fh *fhp) 294 { 295 struct inode *inode = d_inode(fhp->fh_dentry); 296 297 if (!EX_ISSYNC(fhp->fh_export)) 298 return 0; 299 return commit_inode_metadata(inode); 300 } 301 302 /* 303 * Go over the attributes and take care of the small differences between 304 * NFS semantics and what Linux expects. 305 */ 306 static void 307 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap) 308 { 309 /* sanitize the mode change */ 310 if (iap->ia_valid & ATTR_MODE) { 311 iap->ia_mode &= S_IALLUGO; 312 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); 313 } 314 315 /* Revoke setuid/setgid on chown */ 316 if (!S_ISDIR(inode->i_mode) && 317 ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) { 318 iap->ia_valid |= ATTR_KILL_PRIV; 319 if (iap->ia_valid & ATTR_MODE) { 320 /* we're setting mode too, just clear the s*id bits */ 321 iap->ia_mode &= ~S_ISUID; 322 if (iap->ia_mode & S_IXGRP) 323 iap->ia_mode &= ~S_ISGID; 324 } else { 325 /* set ATTR_KILL_* bits and let VFS handle it */ 326 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID); 327 } 328 } 329 } 330 331 static __be32 332 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp, 333 struct iattr *iap) 334 { 335 struct inode *inode = d_inode(fhp->fh_dentry); 336 int host_err; 337 338 if (iap->ia_size < inode->i_size) { 339 __be32 err; 340 341 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 342 NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE); 343 if (err) 344 return err; 345 } 346 347 host_err = get_write_access(inode); 348 if (host_err) 349 goto out_nfserrno; 350 351 host_err = locks_verify_truncate(inode, NULL, iap->ia_size); 352 if (host_err) 353 goto out_put_write_access; 354 return 0; 355 356 out_put_write_access: 357 put_write_access(inode); 358 out_nfserrno: 359 return nfserrno(host_err); 360 } 361 362 /* 363 * Set various file attributes. After this call fhp needs an fh_put. 364 */ 365 __be32 366 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, 367 int check_guard, time64_t guardtime) 368 { 369 struct dentry *dentry; 370 struct inode *inode; 371 int accmode = NFSD_MAY_SATTR; 372 umode_t ftype = 0; 373 __be32 err; 374 int host_err; 375 bool get_write_count; 376 bool size_change = (iap->ia_valid & ATTR_SIZE); 377 378 if (iap->ia_valid & ATTR_SIZE) { 379 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; 380 ftype = S_IFREG; 381 } 382 383 /* 384 * If utimes(2) and friends are called with times not NULL, we should 385 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission 386 * will return EACCES, when the caller's effective UID does not match 387 * the owner of the file, and the caller is not privileged. In this 388 * situation, we should return EPERM(notify_change will return this). 389 */ 390 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) { 391 accmode |= NFSD_MAY_OWNER_OVERRIDE; 392 if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET))) 393 accmode |= NFSD_MAY_WRITE; 394 } 395 396 /* Callers that do fh_verify should do the fh_want_write: */ 397 get_write_count = !fhp->fh_dentry; 398 399 /* Get inode */ 400 err = fh_verify(rqstp, fhp, ftype, accmode); 401 if (err) 402 return err; 403 if (get_write_count) { 404 host_err = fh_want_write(fhp); 405 if (host_err) 406 goto out; 407 } 408 409 dentry = fhp->fh_dentry; 410 inode = d_inode(dentry); 411 412 /* Ignore any mode updates on symlinks */ 413 if (S_ISLNK(inode->i_mode)) 414 iap->ia_valid &= ~ATTR_MODE; 415 416 if (!iap->ia_valid) 417 return 0; 418 419 nfsd_sanitize_attrs(inode, iap); 420 421 if (check_guard && guardtime != inode->i_ctime.tv_sec) 422 return nfserr_notsync; 423 424 /* 425 * The size case is special, it changes the file in addition to the 426 * attributes, and file systems don't expect it to be mixed with 427 * "random" attribute changes. We thus split out the size change 428 * into a separate call to ->setattr, and do the rest as a separate 429 * setattr call. 430 */ 431 if (size_change) { 432 err = nfsd_get_write_access(rqstp, fhp, iap); 433 if (err) 434 return err; 435 } 436 437 fh_lock(fhp); 438 if (size_change) { 439 /* 440 * RFC5661, Section 18.30.4: 441 * Changing the size of a file with SETATTR indirectly 442 * changes the time_modify and change attributes. 443 * 444 * (and similar for the older RFCs) 445 */ 446 struct iattr size_attr = { 447 .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME, 448 .ia_size = iap->ia_size, 449 }; 450 451 host_err = notify_change(dentry, &size_attr, NULL); 452 if (host_err) 453 goto out_unlock; 454 iap->ia_valid &= ~ATTR_SIZE; 455 456 /* 457 * Avoid the additional setattr call below if the only other 458 * attribute that the client sends is the mtime, as we update 459 * it as part of the size change above. 460 */ 461 if ((iap->ia_valid & ~ATTR_MTIME) == 0) 462 goto out_unlock; 463 } 464 465 iap->ia_valid |= ATTR_CTIME; 466 host_err = notify_change(dentry, iap, NULL); 467 468 out_unlock: 469 fh_unlock(fhp); 470 if (size_change) 471 put_write_access(inode); 472 out: 473 if (!host_err) 474 host_err = commit_metadata(fhp); 475 return nfserrno(host_err); 476 } 477 478 #if defined(CONFIG_NFSD_V4) 479 /* 480 * NFS junction information is stored in an extended attribute. 481 */ 482 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs" 483 484 /** 485 * nfsd4_is_junction - Test if an object could be an NFS junction 486 * 487 * @dentry: object to test 488 * 489 * Returns 1 if "dentry" appears to contain NFS junction information. 490 * Otherwise 0 is returned. 491 */ 492 int nfsd4_is_junction(struct dentry *dentry) 493 { 494 struct inode *inode = d_inode(dentry); 495 496 if (inode == NULL) 497 return 0; 498 if (inode->i_mode & S_IXUGO) 499 return 0; 500 if (!(inode->i_mode & S_ISVTX)) 501 return 0; 502 if (vfs_getxattr(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0) 503 return 0; 504 return 1; 505 } 506 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL 507 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp, 508 struct xdr_netobj *label) 509 { 510 __be32 error; 511 int host_error; 512 struct dentry *dentry; 513 514 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); 515 if (error) 516 return error; 517 518 dentry = fhp->fh_dentry; 519 520 inode_lock(d_inode(dentry)); 521 host_error = security_inode_setsecctx(dentry, label->data, label->len); 522 inode_unlock(d_inode(dentry)); 523 return nfserrno(host_error); 524 } 525 #else 526 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp, 527 struct xdr_netobj *label) 528 { 529 return nfserr_notsupp; 530 } 531 #endif 532 533 __be32 nfsd4_clone_file_range(struct file *src, u64 src_pos, struct file *dst, 534 u64 dst_pos, u64 count, bool sync) 535 { 536 loff_t cloned; 537 538 cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0); 539 if (cloned < 0) 540 return nfserrno(cloned); 541 if (count && cloned != count) 542 return nfserrno(-EINVAL); 543 if (sync) { 544 loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX; 545 int status = vfs_fsync_range(dst, dst_pos, dst_end, 0); 546 547 if (!status) 548 status = commit_inode_metadata(file_inode(src)); 549 if (status < 0) 550 return nfserrno(status); 551 } 552 return 0; 553 } 554 555 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst, 556 u64 dst_pos, u64 count) 557 { 558 559 /* 560 * Limit copy to 4MB to prevent indefinitely blocking an nfsd 561 * thread and client rpc slot. The choice of 4MB is somewhat 562 * arbitrary. We might instead base this on r/wsize, or make it 563 * tunable, or use a time instead of a byte limit, or implement 564 * asynchronous copy. In theory a client could also recognize a 565 * limit like this and pipeline multiple COPY requests. 566 */ 567 count = min_t(u64, count, 1 << 22); 568 return vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0); 569 } 570 571 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp, 572 struct file *file, loff_t offset, loff_t len, 573 int flags) 574 { 575 int error; 576 577 if (!S_ISREG(file_inode(file)->i_mode)) 578 return nfserr_inval; 579 580 error = vfs_fallocate(file, flags, offset, len); 581 if (!error) 582 error = commit_metadata(fhp); 583 584 return nfserrno(error); 585 } 586 #endif /* defined(CONFIG_NFSD_V4) */ 587 588 #ifdef CONFIG_NFSD_V3 589 /* 590 * Check server access rights to a file system object 591 */ 592 struct accessmap { 593 u32 access; 594 int how; 595 }; 596 static struct accessmap nfs3_regaccess[] = { 597 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 598 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 599 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, 600 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, 601 602 { 0, 0 } 603 }; 604 605 static struct accessmap nfs3_diraccess[] = { 606 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 607 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, 608 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, 609 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, 610 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, 611 612 { 0, 0 } 613 }; 614 615 static struct accessmap nfs3_anyaccess[] = { 616 /* Some clients - Solaris 2.6 at least, make an access call 617 * to the server to check for access for things like /dev/null 618 * (which really, the server doesn't care about). So 619 * We provide simple access checking for them, looking 620 * mainly at mode bits, and we make sure to ignore read-only 621 * filesystem checks 622 */ 623 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 624 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 625 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 626 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 627 628 { 0, 0 } 629 }; 630 631 __be32 632 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 633 { 634 struct accessmap *map; 635 struct svc_export *export; 636 struct dentry *dentry; 637 u32 query, result = 0, sresult = 0; 638 __be32 error; 639 640 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP); 641 if (error) 642 goto out; 643 644 export = fhp->fh_export; 645 dentry = fhp->fh_dentry; 646 647 if (d_is_reg(dentry)) 648 map = nfs3_regaccess; 649 else if (d_is_dir(dentry)) 650 map = nfs3_diraccess; 651 else 652 map = nfs3_anyaccess; 653 654 655 query = *access; 656 for (; map->access; map++) { 657 if (map->access & query) { 658 __be32 err2; 659 660 sresult |= map->access; 661 662 err2 = nfsd_permission(rqstp, export, dentry, map->how); 663 switch (err2) { 664 case nfs_ok: 665 result |= map->access; 666 break; 667 668 /* the following error codes just mean the access was not allowed, 669 * rather than an error occurred */ 670 case nfserr_rofs: 671 case nfserr_acces: 672 case nfserr_perm: 673 /* simply don't "or" in the access bit. */ 674 break; 675 default: 676 error = err2; 677 goto out; 678 } 679 } 680 } 681 *access = result; 682 if (supported) 683 *supported = sresult; 684 685 out: 686 return error; 687 } 688 #endif /* CONFIG_NFSD_V3 */ 689 690 int nfsd_open_break_lease(struct inode *inode, int access) 691 { 692 unsigned int mode; 693 694 if (access & NFSD_MAY_NOT_BREAK_LEASE) 695 return 0; 696 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY; 697 return break_lease(inode, mode | O_NONBLOCK); 698 } 699 700 /* 701 * Open an existing file or directory. 702 * The may_flags argument indicates the type of open (read/write/lock) 703 * and additional flags. 704 * N.B. After this call fhp needs an fh_put 705 */ 706 static __be32 707 __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, 708 int may_flags, struct file **filp) 709 { 710 struct path path; 711 struct inode *inode; 712 struct file *file; 713 int flags = O_RDONLY|O_LARGEFILE; 714 __be32 err; 715 int host_err = 0; 716 717 path.mnt = fhp->fh_export->ex_path.mnt; 718 path.dentry = fhp->fh_dentry; 719 inode = d_inode(path.dentry); 720 721 /* Disallow write access to files with the append-only bit set 722 * or any access when mandatory locking enabled 723 */ 724 err = nfserr_perm; 725 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE)) 726 goto out; 727 /* 728 * We must ignore files (but only files) which might have mandatory 729 * locks on them because there is no way to know if the accesser has 730 * the lock. 731 */ 732 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode)) 733 goto out; 734 735 if (!inode->i_fop) 736 goto out; 737 738 host_err = nfsd_open_break_lease(inode, may_flags); 739 if (host_err) /* NOMEM or WOULDBLOCK */ 740 goto out_nfserr; 741 742 if (may_flags & NFSD_MAY_WRITE) { 743 if (may_flags & NFSD_MAY_READ) 744 flags = O_RDWR|O_LARGEFILE; 745 else 746 flags = O_WRONLY|O_LARGEFILE; 747 } 748 749 file = dentry_open(&path, flags, current_cred()); 750 if (IS_ERR(file)) { 751 host_err = PTR_ERR(file); 752 goto out_nfserr; 753 } 754 755 host_err = ima_file_check(file, may_flags); 756 if (host_err) { 757 fput(file); 758 goto out_nfserr; 759 } 760 761 if (may_flags & NFSD_MAY_64BIT_COOKIE) 762 file->f_mode |= FMODE_64BITHASH; 763 else 764 file->f_mode |= FMODE_32BITHASH; 765 766 *filp = file; 767 out_nfserr: 768 err = nfserrno(host_err); 769 out: 770 return err; 771 } 772 773 __be32 774 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, 775 int may_flags, struct file **filp) 776 { 777 __be32 err; 778 779 validate_process_creds(); 780 /* 781 * If we get here, then the client has already done an "open", 782 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 783 * in case a chmod has now revoked permission. 784 * 785 * Arguably we should also allow the owner override for 786 * directories, but we never have and it doesn't seem to have 787 * caused anyone a problem. If we were to change this, note 788 * also that our filldir callbacks would need a variant of 789 * lookup_one_len that doesn't check permissions. 790 */ 791 if (type == S_IFREG) 792 may_flags |= NFSD_MAY_OWNER_OVERRIDE; 793 err = fh_verify(rqstp, fhp, type, may_flags); 794 if (!err) 795 err = __nfsd_open(rqstp, fhp, type, may_flags, filp); 796 validate_process_creds(); 797 return err; 798 } 799 800 __be32 801 nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, 802 int may_flags, struct file **filp) 803 { 804 __be32 err; 805 806 validate_process_creds(); 807 err = __nfsd_open(rqstp, fhp, type, may_flags, filp); 808 validate_process_creds(); 809 return err; 810 } 811 812 /* 813 * Grab and keep cached pages associated with a file in the svc_rqst 814 * so that they can be passed to the network sendmsg/sendpage routines 815 * directly. They will be released after the sending has completed. 816 */ 817 static int 818 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 819 struct splice_desc *sd) 820 { 821 struct svc_rqst *rqstp = sd->u.data; 822 struct page **pp = rqstp->rq_next_page; 823 struct page *page = buf->page; 824 size_t size; 825 826 size = sd->len; 827 828 if (rqstp->rq_res.page_len == 0) { 829 get_page(page); 830 put_page(*rqstp->rq_next_page); 831 *(rqstp->rq_next_page++) = page; 832 rqstp->rq_res.page_base = buf->offset; 833 rqstp->rq_res.page_len = size; 834 } else if (page != pp[-1]) { 835 get_page(page); 836 if (*rqstp->rq_next_page) 837 put_page(*rqstp->rq_next_page); 838 *(rqstp->rq_next_page++) = page; 839 rqstp->rq_res.page_len += size; 840 } else 841 rqstp->rq_res.page_len += size; 842 843 return size; 844 } 845 846 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, 847 struct splice_desc *sd) 848 { 849 return __splice_from_pipe(pipe, sd, nfsd_splice_actor); 850 } 851 852 static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len, 853 size_t expected) 854 { 855 if (expected != 0 && len == 0) 856 return 1; 857 if (offset+len >= i_size_read(file_inode(file))) 858 return 1; 859 return 0; 860 } 861 862 static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 863 struct file *file, loff_t offset, 864 unsigned long *count, u32 *eof, ssize_t host_err) 865 { 866 if (host_err >= 0) { 867 nfsdstats.io_read += host_err; 868 *eof = nfsd_eof_on_read(file, offset, host_err, *count); 869 *count = host_err; 870 fsnotify_access(file); 871 trace_nfsd_read_io_done(rqstp, fhp, offset, *count); 872 return 0; 873 } else { 874 trace_nfsd_read_err(rqstp, fhp, offset, host_err); 875 return nfserrno(host_err); 876 } 877 } 878 879 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 880 struct file *file, loff_t offset, unsigned long *count, 881 u32 *eof) 882 { 883 struct splice_desc sd = { 884 .len = 0, 885 .total_len = *count, 886 .pos = offset, 887 .u.data = rqstp, 888 }; 889 ssize_t host_err; 890 891 trace_nfsd_read_splice(rqstp, fhp, offset, *count); 892 rqstp->rq_next_page = rqstp->rq_respages + 1; 893 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); 894 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err); 895 } 896 897 __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp, 898 struct file *file, loff_t offset, 899 struct kvec *vec, int vlen, unsigned long *count, 900 u32 *eof) 901 { 902 struct iov_iter iter; 903 loff_t ppos = offset; 904 ssize_t host_err; 905 906 trace_nfsd_read_vector(rqstp, fhp, offset, *count); 907 iov_iter_kvec(&iter, READ, vec, vlen, *count); 908 host_err = vfs_iter_read(file, &iter, &ppos, 0); 909 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err); 910 } 911 912 /* 913 * Gathered writes: If another process is currently writing to the file, 914 * there's a high chance this is another nfsd (triggered by a bulk write 915 * from a client's biod). Rather than syncing the file with each write 916 * request, we sleep for 10 msec. 917 * 918 * I don't know if this roughly approximates C. Juszak's idea of 919 * gathered writes, but it's a nice and simple solution (IMHO), and it 920 * seems to work:-) 921 * 922 * Note: we do this only in the NFSv2 case, since v3 and higher have a 923 * better tool (separate unstable writes and commits) for solving this 924 * problem. 925 */ 926 static int wait_for_concurrent_writes(struct file *file) 927 { 928 struct inode *inode = file_inode(file); 929 static ino_t last_ino; 930 static dev_t last_dev; 931 int err = 0; 932 933 if (atomic_read(&inode->i_writecount) > 1 934 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 935 dprintk("nfsd: write defer %d\n", task_pid_nr(current)); 936 msleep(10); 937 dprintk("nfsd: write resume %d\n", task_pid_nr(current)); 938 } 939 940 if (inode->i_state & I_DIRTY) { 941 dprintk("nfsd: write sync %d\n", task_pid_nr(current)); 942 err = vfs_fsync(file, 0); 943 } 944 last_ino = inode->i_ino; 945 last_dev = inode->i_sb->s_dev; 946 return err; 947 } 948 949 __be32 950 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, 951 loff_t offset, struct kvec *vec, int vlen, 952 unsigned long *cnt, int stable) 953 { 954 struct svc_export *exp; 955 struct iov_iter iter; 956 __be32 nfserr; 957 int host_err; 958 int use_wgather; 959 loff_t pos = offset; 960 unsigned int pflags = current->flags; 961 rwf_t flags = 0; 962 963 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt); 964 965 if (test_bit(RQ_LOCAL, &rqstp->rq_flags)) 966 /* 967 * We want less throttling in balance_dirty_pages() 968 * and shrink_inactive_list() so that nfs to 969 * localhost doesn't cause nfsd to lock up due to all 970 * the client's dirty pages or its congested queue. 971 */ 972 current->flags |= PF_LESS_THROTTLE; 973 974 exp = fhp->fh_export; 975 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); 976 977 if (!EX_ISSYNC(exp)) 978 stable = NFS_UNSTABLE; 979 980 if (stable && !use_wgather) 981 flags |= RWF_SYNC; 982 983 iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt); 984 host_err = vfs_iter_write(file, &iter, &pos, flags); 985 if (host_err < 0) 986 goto out_nfserr; 987 *cnt = host_err; 988 nfsdstats.io_write += *cnt; 989 fsnotify_modify(file); 990 991 if (stable && use_wgather) { 992 host_err = wait_for_concurrent_writes(file); 993 if (host_err < 0) 994 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp), 995 nfsd_net_id)); 996 } 997 998 out_nfserr: 999 if (host_err >= 0) { 1000 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt); 1001 nfserr = nfs_ok; 1002 } else { 1003 trace_nfsd_write_err(rqstp, fhp, offset, host_err); 1004 nfserr = nfserrno(host_err); 1005 } 1006 if (test_bit(RQ_LOCAL, &rqstp->rq_flags)) 1007 current_restore_flags(pflags, PF_LESS_THROTTLE); 1008 return nfserr; 1009 } 1010 1011 /* 1012 * Read data from a file. count must contain the requested read count 1013 * on entry. On return, *count contains the number of bytes actually read. 1014 * N.B. After this call fhp needs an fh_put 1015 */ 1016 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 1017 loff_t offset, struct kvec *vec, int vlen, unsigned long *count, 1018 u32 *eof) 1019 { 1020 struct nfsd_file *nf; 1021 struct file *file; 1022 __be32 err; 1023 1024 trace_nfsd_read_start(rqstp, fhp, offset, *count); 1025 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf); 1026 if (err) 1027 return err; 1028 1029 file = nf->nf_file; 1030 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags)) 1031 err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof); 1032 else 1033 err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count, eof); 1034 1035 nfsd_file_put(nf); 1036 1037 trace_nfsd_read_done(rqstp, fhp, offset, *count); 1038 1039 return err; 1040 } 1041 1042 /* 1043 * Write data to a file. 1044 * The stable flag requests synchronous writes. 1045 * N.B. After this call fhp needs an fh_put 1046 */ 1047 __be32 1048 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, 1049 struct kvec *vec, int vlen, unsigned long *cnt, int stable) 1050 { 1051 struct nfsd_file *nf; 1052 __be32 err; 1053 1054 trace_nfsd_write_start(rqstp, fhp, offset, *cnt); 1055 1056 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_WRITE, &nf); 1057 if (err) 1058 goto out; 1059 1060 err = nfsd_vfs_write(rqstp, fhp, nf->nf_file, offset, vec, 1061 vlen, cnt, stable); 1062 nfsd_file_put(nf); 1063 out: 1064 trace_nfsd_write_done(rqstp, fhp, offset, *cnt); 1065 return err; 1066 } 1067 1068 #ifdef CONFIG_NFSD_V3 1069 /* 1070 * Commit all pending writes to stable storage. 1071 * 1072 * Note: we only guarantee that data that lies within the range specified 1073 * by the 'offset' and 'count' parameters will be synced. 1074 * 1075 * Unfortunately we cannot lock the file to make sure we return full WCC 1076 * data to the client, as locking happens lower down in the filesystem. 1077 */ 1078 __be32 1079 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, 1080 loff_t offset, unsigned long count) 1081 { 1082 struct nfsd_file *nf; 1083 loff_t end = LLONG_MAX; 1084 __be32 err = nfserr_inval; 1085 1086 if (offset < 0) 1087 goto out; 1088 if (count != 0) { 1089 end = offset + (loff_t)count - 1; 1090 if (end < offset) 1091 goto out; 1092 } 1093 1094 err = nfsd_file_acquire(rqstp, fhp, 1095 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &nf); 1096 if (err) 1097 goto out; 1098 if (EX_ISSYNC(fhp->fh_export)) { 1099 int err2 = vfs_fsync_range(nf->nf_file, offset, end, 0); 1100 1101 switch (err2) { 1102 case 0: 1103 break; 1104 case -EINVAL: 1105 err = nfserr_notsupp; 1106 break; 1107 default: 1108 err = nfserrno(err2); 1109 nfsd_reset_boot_verifier(net_generic(nf->nf_net, 1110 nfsd_net_id)); 1111 } 1112 } 1113 1114 nfsd_file_put(nf); 1115 out: 1116 return err; 1117 } 1118 #endif /* CONFIG_NFSD_V3 */ 1119 1120 static __be32 1121 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp, 1122 struct iattr *iap) 1123 { 1124 /* 1125 * Mode has already been set earlier in create: 1126 */ 1127 iap->ia_valid &= ~ATTR_MODE; 1128 /* 1129 * Setting uid/gid works only for root. Irix appears to 1130 * send along the gid on create when it tries to implement 1131 * setgid directories via NFS: 1132 */ 1133 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID)) 1134 iap->ia_valid &= ~(ATTR_UID|ATTR_GID); 1135 if (iap->ia_valid) 1136 return nfsd_setattr(rqstp, resfhp, iap, 0, (time64_t)0); 1137 /* Callers expect file metadata to be committed here */ 1138 return nfserrno(commit_metadata(resfhp)); 1139 } 1140 1141 /* HPUX client sometimes creates a file in mode 000, and sets size to 0. 1142 * setting size to 0 may fail for some specific file systems by the permission 1143 * checking which requires WRITE permission but the mode is 000. 1144 * we ignore the resizing(to 0) on the just new created file, since the size is 1145 * 0 after file created. 1146 * 1147 * call this only after vfs_create() is called. 1148 * */ 1149 static void 1150 nfsd_check_ignore_resizing(struct iattr *iap) 1151 { 1152 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) 1153 iap->ia_valid &= ~ATTR_SIZE; 1154 } 1155 1156 /* The parent directory should already be locked: */ 1157 __be32 1158 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp, 1159 char *fname, int flen, struct iattr *iap, 1160 int type, dev_t rdev, struct svc_fh *resfhp) 1161 { 1162 struct dentry *dentry, *dchild; 1163 struct inode *dirp; 1164 __be32 err; 1165 __be32 err2; 1166 int host_err; 1167 1168 dentry = fhp->fh_dentry; 1169 dirp = d_inode(dentry); 1170 1171 dchild = dget(resfhp->fh_dentry); 1172 if (!fhp->fh_locked) { 1173 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n", 1174 dentry); 1175 err = nfserr_io; 1176 goto out; 1177 } 1178 1179 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE); 1180 if (err) 1181 goto out; 1182 1183 if (!(iap->ia_valid & ATTR_MODE)) 1184 iap->ia_mode = 0; 1185 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1186 1187 err = 0; 1188 host_err = 0; 1189 switch (type) { 1190 case S_IFREG: 1191 host_err = vfs_create(dirp, dchild, iap->ia_mode, true); 1192 if (!host_err) 1193 nfsd_check_ignore_resizing(iap); 1194 break; 1195 case S_IFDIR: 1196 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); 1197 if (!host_err && unlikely(d_unhashed(dchild))) { 1198 struct dentry *d; 1199 d = lookup_one_len(dchild->d_name.name, 1200 dchild->d_parent, 1201 dchild->d_name.len); 1202 if (IS_ERR(d)) { 1203 host_err = PTR_ERR(d); 1204 break; 1205 } 1206 if (unlikely(d_is_negative(d))) { 1207 dput(d); 1208 err = nfserr_serverfault; 1209 goto out; 1210 } 1211 dput(resfhp->fh_dentry); 1212 resfhp->fh_dentry = dget(d); 1213 err = fh_update(resfhp); 1214 dput(dchild); 1215 dchild = d; 1216 if (err) 1217 goto out; 1218 } 1219 break; 1220 case S_IFCHR: 1221 case S_IFBLK: 1222 case S_IFIFO: 1223 case S_IFSOCK: 1224 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); 1225 break; 1226 default: 1227 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", 1228 type); 1229 host_err = -EINVAL; 1230 } 1231 if (host_err < 0) 1232 goto out_nfserr; 1233 1234 err = nfsd_create_setattr(rqstp, resfhp, iap); 1235 1236 /* 1237 * nfsd_create_setattr already committed the child. Transactional 1238 * filesystems had a chance to commit changes for both parent and 1239 * child simultaneously making the following commit_metadata a 1240 * noop. 1241 */ 1242 err2 = nfserrno(commit_metadata(fhp)); 1243 if (err2) 1244 err = err2; 1245 /* 1246 * Update the file handle to get the new inode info. 1247 */ 1248 if (!err) 1249 err = fh_update(resfhp); 1250 out: 1251 dput(dchild); 1252 return err; 1253 1254 out_nfserr: 1255 err = nfserrno(host_err); 1256 goto out; 1257 } 1258 1259 /* 1260 * Create a filesystem object (regular, directory, special). 1261 * Note that the parent directory is left locked. 1262 * 1263 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1264 */ 1265 __be32 1266 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1267 char *fname, int flen, struct iattr *iap, 1268 int type, dev_t rdev, struct svc_fh *resfhp) 1269 { 1270 struct dentry *dentry, *dchild = NULL; 1271 __be32 err; 1272 int host_err; 1273 1274 if (isdotent(fname, flen)) 1275 return nfserr_exist; 1276 1277 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP); 1278 if (err) 1279 return err; 1280 1281 dentry = fhp->fh_dentry; 1282 1283 host_err = fh_want_write(fhp); 1284 if (host_err) 1285 return nfserrno(host_err); 1286 1287 fh_lock_nested(fhp, I_MUTEX_PARENT); 1288 dchild = lookup_one_len(fname, dentry, flen); 1289 host_err = PTR_ERR(dchild); 1290 if (IS_ERR(dchild)) 1291 return nfserrno(host_err); 1292 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1293 /* 1294 * We unconditionally drop our ref to dchild as fh_compose will have 1295 * already grabbed its own ref for it. 1296 */ 1297 dput(dchild); 1298 if (err) 1299 return err; 1300 return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type, 1301 rdev, resfhp); 1302 } 1303 1304 #ifdef CONFIG_NFSD_V3 1305 1306 /* 1307 * NFSv3 and NFSv4 version of nfsd_create 1308 */ 1309 __be32 1310 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1311 char *fname, int flen, struct iattr *iap, 1312 struct svc_fh *resfhp, int createmode, u32 *verifier, 1313 bool *truncp, bool *created) 1314 { 1315 struct dentry *dentry, *dchild = NULL; 1316 struct inode *dirp; 1317 __be32 err; 1318 int host_err; 1319 __u32 v_mtime=0, v_atime=0; 1320 1321 err = nfserr_perm; 1322 if (!flen) 1323 goto out; 1324 err = nfserr_exist; 1325 if (isdotent(fname, flen)) 1326 goto out; 1327 if (!(iap->ia_valid & ATTR_MODE)) 1328 iap->ia_mode = 0; 1329 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); 1330 if (err) 1331 goto out; 1332 1333 dentry = fhp->fh_dentry; 1334 dirp = d_inode(dentry); 1335 1336 host_err = fh_want_write(fhp); 1337 if (host_err) 1338 goto out_nfserr; 1339 1340 fh_lock_nested(fhp, I_MUTEX_PARENT); 1341 1342 /* 1343 * Compose the response file handle. 1344 */ 1345 dchild = lookup_one_len(fname, dentry, flen); 1346 host_err = PTR_ERR(dchild); 1347 if (IS_ERR(dchild)) 1348 goto out_nfserr; 1349 1350 /* If file doesn't exist, check for permissions to create one */ 1351 if (d_really_is_negative(dchild)) { 1352 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1353 if (err) 1354 goto out; 1355 } 1356 1357 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1358 if (err) 1359 goto out; 1360 1361 if (nfsd_create_is_exclusive(createmode)) { 1362 /* solaris7 gets confused (bugid 4218508) if these have 1363 * the high bit set, so just clear the high bits. If this is 1364 * ever changed to use different attrs for storing the 1365 * verifier, then do_open_lookup() will also need to be fixed 1366 * accordingly. 1367 */ 1368 v_mtime = verifier[0]&0x7fffffff; 1369 v_atime = verifier[1]&0x7fffffff; 1370 } 1371 1372 if (d_really_is_positive(dchild)) { 1373 err = 0; 1374 1375 switch (createmode) { 1376 case NFS3_CREATE_UNCHECKED: 1377 if (! d_is_reg(dchild)) 1378 goto out; 1379 else if (truncp) { 1380 /* in nfsv4, we need to treat this case a little 1381 * differently. we don't want to truncate the 1382 * file now; this would be wrong if the OPEN 1383 * fails for some other reason. furthermore, 1384 * if the size is nonzero, we should ignore it 1385 * according to spec! 1386 */ 1387 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; 1388 } 1389 else { 1390 iap->ia_valid &= ATTR_SIZE; 1391 goto set_attr; 1392 } 1393 break; 1394 case NFS3_CREATE_EXCLUSIVE: 1395 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime 1396 && d_inode(dchild)->i_atime.tv_sec == v_atime 1397 && d_inode(dchild)->i_size == 0 ) { 1398 if (created) 1399 *created = true; 1400 break; 1401 } 1402 /* fall through */ 1403 case NFS4_CREATE_EXCLUSIVE4_1: 1404 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime 1405 && d_inode(dchild)->i_atime.tv_sec == v_atime 1406 && d_inode(dchild)->i_size == 0 ) { 1407 if (created) 1408 *created = true; 1409 goto set_attr; 1410 } 1411 /* fall through */ 1412 case NFS3_CREATE_GUARDED: 1413 err = nfserr_exist; 1414 } 1415 fh_drop_write(fhp); 1416 goto out; 1417 } 1418 1419 host_err = vfs_create(dirp, dchild, iap->ia_mode, true); 1420 if (host_err < 0) { 1421 fh_drop_write(fhp); 1422 goto out_nfserr; 1423 } 1424 if (created) 1425 *created = true; 1426 1427 nfsd_check_ignore_resizing(iap); 1428 1429 if (nfsd_create_is_exclusive(createmode)) { 1430 /* Cram the verifier into atime/mtime */ 1431 iap->ia_valid = ATTR_MTIME|ATTR_ATIME 1432 | ATTR_MTIME_SET|ATTR_ATIME_SET; 1433 /* XXX someone who knows this better please fix it for nsec */ 1434 iap->ia_mtime.tv_sec = v_mtime; 1435 iap->ia_atime.tv_sec = v_atime; 1436 iap->ia_mtime.tv_nsec = 0; 1437 iap->ia_atime.tv_nsec = 0; 1438 } 1439 1440 set_attr: 1441 err = nfsd_create_setattr(rqstp, resfhp, iap); 1442 1443 /* 1444 * nfsd_create_setattr already committed the child 1445 * (and possibly also the parent). 1446 */ 1447 if (!err) 1448 err = nfserrno(commit_metadata(fhp)); 1449 1450 /* 1451 * Update the filehandle to get the new inode info. 1452 */ 1453 if (!err) 1454 err = fh_update(resfhp); 1455 1456 out: 1457 fh_unlock(fhp); 1458 if (dchild && !IS_ERR(dchild)) 1459 dput(dchild); 1460 fh_drop_write(fhp); 1461 return err; 1462 1463 out_nfserr: 1464 err = nfserrno(host_err); 1465 goto out; 1466 } 1467 #endif /* CONFIG_NFSD_V3 */ 1468 1469 /* 1470 * Read a symlink. On entry, *lenp must contain the maximum path length that 1471 * fits into the buffer. On return, it contains the true length. 1472 * N.B. After this call fhp needs an fh_put 1473 */ 1474 __be32 1475 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1476 { 1477 __be32 err; 1478 const char *link; 1479 struct path path; 1480 DEFINE_DELAYED_CALL(done); 1481 int len; 1482 1483 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); 1484 if (unlikely(err)) 1485 return err; 1486 1487 path.mnt = fhp->fh_export->ex_path.mnt; 1488 path.dentry = fhp->fh_dentry; 1489 1490 if (unlikely(!d_is_symlink(path.dentry))) 1491 return nfserr_inval; 1492 1493 touch_atime(&path); 1494 1495 link = vfs_get_link(path.dentry, &done); 1496 if (IS_ERR(link)) 1497 return nfserrno(PTR_ERR(link)); 1498 1499 len = strlen(link); 1500 if (len < *lenp) 1501 *lenp = len; 1502 memcpy(buf, link, *lenp); 1503 do_delayed_call(&done); 1504 return 0; 1505 } 1506 1507 /* 1508 * Create a symlink and look up its inode 1509 * N.B. After this call _both_ fhp and resfhp need an fh_put 1510 */ 1511 __be32 1512 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1513 char *fname, int flen, 1514 char *path, 1515 struct svc_fh *resfhp) 1516 { 1517 struct dentry *dentry, *dnew; 1518 __be32 err, cerr; 1519 int host_err; 1520 1521 err = nfserr_noent; 1522 if (!flen || path[0] == '\0') 1523 goto out; 1524 err = nfserr_exist; 1525 if (isdotent(fname, flen)) 1526 goto out; 1527 1528 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1529 if (err) 1530 goto out; 1531 1532 host_err = fh_want_write(fhp); 1533 if (host_err) 1534 goto out_nfserr; 1535 1536 fh_lock(fhp); 1537 dentry = fhp->fh_dentry; 1538 dnew = lookup_one_len(fname, dentry, flen); 1539 host_err = PTR_ERR(dnew); 1540 if (IS_ERR(dnew)) 1541 goto out_nfserr; 1542 1543 host_err = vfs_symlink(d_inode(dentry), dnew, path); 1544 err = nfserrno(host_err); 1545 if (!err) 1546 err = nfserrno(commit_metadata(fhp)); 1547 fh_unlock(fhp); 1548 1549 fh_drop_write(fhp); 1550 1551 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1552 dput(dnew); 1553 if (err==0) err = cerr; 1554 out: 1555 return err; 1556 1557 out_nfserr: 1558 err = nfserrno(host_err); 1559 goto out; 1560 } 1561 1562 /* 1563 * Create a hardlink 1564 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1565 */ 1566 __be32 1567 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1568 char *name, int len, struct svc_fh *tfhp) 1569 { 1570 struct dentry *ddir, *dnew, *dold; 1571 struct inode *dirp; 1572 __be32 err; 1573 int host_err; 1574 1575 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); 1576 if (err) 1577 goto out; 1578 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP); 1579 if (err) 1580 goto out; 1581 err = nfserr_isdir; 1582 if (d_is_dir(tfhp->fh_dentry)) 1583 goto out; 1584 err = nfserr_perm; 1585 if (!len) 1586 goto out; 1587 err = nfserr_exist; 1588 if (isdotent(name, len)) 1589 goto out; 1590 1591 host_err = fh_want_write(tfhp); 1592 if (host_err) { 1593 err = nfserrno(host_err); 1594 goto out; 1595 } 1596 1597 fh_lock_nested(ffhp, I_MUTEX_PARENT); 1598 ddir = ffhp->fh_dentry; 1599 dirp = d_inode(ddir); 1600 1601 dnew = lookup_one_len(name, ddir, len); 1602 host_err = PTR_ERR(dnew); 1603 if (IS_ERR(dnew)) 1604 goto out_nfserr; 1605 1606 dold = tfhp->fh_dentry; 1607 1608 err = nfserr_noent; 1609 if (d_really_is_negative(dold)) 1610 goto out_dput; 1611 host_err = vfs_link(dold, dirp, dnew, NULL); 1612 if (!host_err) { 1613 err = nfserrno(commit_metadata(ffhp)); 1614 if (!err) 1615 err = nfserrno(commit_metadata(tfhp)); 1616 } else { 1617 if (host_err == -EXDEV && rqstp->rq_vers == 2) 1618 err = nfserr_acces; 1619 else 1620 err = nfserrno(host_err); 1621 } 1622 out_dput: 1623 dput(dnew); 1624 out_unlock: 1625 fh_unlock(ffhp); 1626 fh_drop_write(tfhp); 1627 out: 1628 return err; 1629 1630 out_nfserr: 1631 err = nfserrno(host_err); 1632 goto out_unlock; 1633 } 1634 1635 static void 1636 nfsd_close_cached_files(struct dentry *dentry) 1637 { 1638 struct inode *inode = d_inode(dentry); 1639 1640 if (inode && S_ISREG(inode->i_mode)) 1641 nfsd_file_close_inode_sync(inode); 1642 } 1643 1644 static bool 1645 nfsd_has_cached_files(struct dentry *dentry) 1646 { 1647 bool ret = false; 1648 struct inode *inode = d_inode(dentry); 1649 1650 if (inode && S_ISREG(inode->i_mode)) 1651 ret = nfsd_file_is_cached(inode); 1652 return ret; 1653 } 1654 1655 /* 1656 * Rename a file 1657 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1658 */ 1659 __be32 1660 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1661 struct svc_fh *tfhp, char *tname, int tlen) 1662 { 1663 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1664 struct inode *fdir, *tdir; 1665 __be32 err; 1666 int host_err; 1667 bool has_cached = false; 1668 1669 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); 1670 if (err) 1671 goto out; 1672 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE); 1673 if (err) 1674 goto out; 1675 1676 fdentry = ffhp->fh_dentry; 1677 fdir = d_inode(fdentry); 1678 1679 tdentry = tfhp->fh_dentry; 1680 tdir = d_inode(tdentry); 1681 1682 err = nfserr_perm; 1683 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1684 goto out; 1685 1686 retry: 1687 host_err = fh_want_write(ffhp); 1688 if (host_err) { 1689 err = nfserrno(host_err); 1690 goto out; 1691 } 1692 1693 /* cannot use fh_lock as we need deadlock protective ordering 1694 * so do it by hand */ 1695 trap = lock_rename(tdentry, fdentry); 1696 ffhp->fh_locked = tfhp->fh_locked = true; 1697 fill_pre_wcc(ffhp); 1698 fill_pre_wcc(tfhp); 1699 1700 odentry = lookup_one_len(fname, fdentry, flen); 1701 host_err = PTR_ERR(odentry); 1702 if (IS_ERR(odentry)) 1703 goto out_nfserr; 1704 1705 host_err = -ENOENT; 1706 if (d_really_is_negative(odentry)) 1707 goto out_dput_old; 1708 host_err = -EINVAL; 1709 if (odentry == trap) 1710 goto out_dput_old; 1711 1712 ndentry = lookup_one_len(tname, tdentry, tlen); 1713 host_err = PTR_ERR(ndentry); 1714 if (IS_ERR(ndentry)) 1715 goto out_dput_old; 1716 host_err = -ENOTEMPTY; 1717 if (ndentry == trap) 1718 goto out_dput_new; 1719 1720 host_err = -EXDEV; 1721 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) 1722 goto out_dput_new; 1723 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry) 1724 goto out_dput_new; 1725 1726 if (nfsd_has_cached_files(ndentry)) { 1727 has_cached = true; 1728 goto out_dput_old; 1729 } else { 1730 host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0); 1731 if (!host_err) { 1732 host_err = commit_metadata(tfhp); 1733 if (!host_err) 1734 host_err = commit_metadata(ffhp); 1735 } 1736 } 1737 out_dput_new: 1738 dput(ndentry); 1739 out_dput_old: 1740 dput(odentry); 1741 out_nfserr: 1742 err = nfserrno(host_err); 1743 /* 1744 * We cannot rely on fh_unlock on the two filehandles, 1745 * as that would do the wrong thing if the two directories 1746 * were the same, so again we do it by hand. 1747 */ 1748 if (!has_cached) { 1749 fill_post_wcc(ffhp); 1750 fill_post_wcc(tfhp); 1751 } 1752 unlock_rename(tdentry, fdentry); 1753 ffhp->fh_locked = tfhp->fh_locked = false; 1754 fh_drop_write(ffhp); 1755 1756 /* 1757 * If the target dentry has cached open files, then we need to try to 1758 * close them prior to doing the rename. Flushing delayed fput 1759 * shouldn't be done with locks held however, so we delay it until this 1760 * point and then reattempt the whole shebang. 1761 */ 1762 if (has_cached) { 1763 has_cached = false; 1764 nfsd_close_cached_files(ndentry); 1765 dput(ndentry); 1766 goto retry; 1767 } 1768 out: 1769 return err; 1770 } 1771 1772 /* 1773 * Unlink a file or directory 1774 * N.B. After this call fhp needs an fh_put 1775 */ 1776 __be32 1777 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1778 char *fname, int flen) 1779 { 1780 struct dentry *dentry, *rdentry; 1781 struct inode *dirp; 1782 __be32 err; 1783 int host_err; 1784 1785 err = nfserr_acces; 1786 if (!flen || isdotent(fname, flen)) 1787 goto out; 1788 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); 1789 if (err) 1790 goto out; 1791 1792 host_err = fh_want_write(fhp); 1793 if (host_err) 1794 goto out_nfserr; 1795 1796 fh_lock_nested(fhp, I_MUTEX_PARENT); 1797 dentry = fhp->fh_dentry; 1798 dirp = d_inode(dentry); 1799 1800 rdentry = lookup_one_len(fname, dentry, flen); 1801 host_err = PTR_ERR(rdentry); 1802 if (IS_ERR(rdentry)) 1803 goto out_drop_write; 1804 1805 if (d_really_is_negative(rdentry)) { 1806 dput(rdentry); 1807 host_err = -ENOENT; 1808 goto out_drop_write; 1809 } 1810 1811 if (!type) 1812 type = d_inode(rdentry)->i_mode & S_IFMT; 1813 1814 if (type != S_IFDIR) { 1815 nfsd_close_cached_files(rdentry); 1816 host_err = vfs_unlink(dirp, rdentry, NULL); 1817 } else { 1818 host_err = vfs_rmdir(dirp, rdentry); 1819 } 1820 1821 if (!host_err) 1822 host_err = commit_metadata(fhp); 1823 dput(rdentry); 1824 1825 out_drop_write: 1826 fh_drop_write(fhp); 1827 out_nfserr: 1828 if (host_err == -EBUSY) { 1829 /* name is mounted-on. There is no perfect 1830 * error status. 1831 */ 1832 if (nfsd_v4client(rqstp)) 1833 err = nfserr_file_open; 1834 else 1835 err = nfserr_acces; 1836 } else { 1837 err = nfserrno(host_err); 1838 } 1839 out: 1840 return err; 1841 } 1842 1843 /* 1844 * We do this buffering because we must not call back into the file 1845 * system's ->lookup() method from the filldir callback. That may well 1846 * deadlock a number of file systems. 1847 * 1848 * This is based heavily on the implementation of same in XFS. 1849 */ 1850 struct buffered_dirent { 1851 u64 ino; 1852 loff_t offset; 1853 int namlen; 1854 unsigned int d_type; 1855 char name[]; 1856 }; 1857 1858 struct readdir_data { 1859 struct dir_context ctx; 1860 char *dirent; 1861 size_t used; 1862 int full; 1863 }; 1864 1865 static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name, 1866 int namlen, loff_t offset, u64 ino, 1867 unsigned int d_type) 1868 { 1869 struct readdir_data *buf = 1870 container_of(ctx, struct readdir_data, ctx); 1871 struct buffered_dirent *de = (void *)(buf->dirent + buf->used); 1872 unsigned int reclen; 1873 1874 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); 1875 if (buf->used + reclen > PAGE_SIZE) { 1876 buf->full = 1; 1877 return -EINVAL; 1878 } 1879 1880 de->namlen = namlen; 1881 de->offset = offset; 1882 de->ino = ino; 1883 de->d_type = d_type; 1884 memcpy(de->name, name, namlen); 1885 buf->used += reclen; 1886 1887 return 0; 1888 } 1889 1890 static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func, 1891 struct readdir_cd *cdp, loff_t *offsetp) 1892 { 1893 struct buffered_dirent *de; 1894 int host_err; 1895 int size; 1896 loff_t offset; 1897 struct readdir_data buf = { 1898 .ctx.actor = nfsd_buffered_filldir, 1899 .dirent = (void *)__get_free_page(GFP_KERNEL) 1900 }; 1901 1902 if (!buf.dirent) 1903 return nfserrno(-ENOMEM); 1904 1905 offset = *offsetp; 1906 1907 while (1) { 1908 unsigned int reclen; 1909 1910 cdp->err = nfserr_eof; /* will be cleared on successful read */ 1911 buf.used = 0; 1912 buf.full = 0; 1913 1914 host_err = iterate_dir(file, &buf.ctx); 1915 if (buf.full) 1916 host_err = 0; 1917 1918 if (host_err < 0) 1919 break; 1920 1921 size = buf.used; 1922 1923 if (!size) 1924 break; 1925 1926 de = (struct buffered_dirent *)buf.dirent; 1927 while (size > 0) { 1928 offset = de->offset; 1929 1930 if (func(cdp, de->name, de->namlen, de->offset, 1931 de->ino, de->d_type)) 1932 break; 1933 1934 if (cdp->err != nfs_ok) 1935 break; 1936 1937 reclen = ALIGN(sizeof(*de) + de->namlen, 1938 sizeof(u64)); 1939 size -= reclen; 1940 de = (struct buffered_dirent *)((char *)de + reclen); 1941 } 1942 if (size > 0) /* We bailed out early */ 1943 break; 1944 1945 offset = vfs_llseek(file, 0, SEEK_CUR); 1946 } 1947 1948 free_page((unsigned long)(buf.dirent)); 1949 1950 if (host_err) 1951 return nfserrno(host_err); 1952 1953 *offsetp = offset; 1954 return cdp->err; 1955 } 1956 1957 /* 1958 * Read entries from a directory. 1959 * The NFSv3/4 verifier we ignore for now. 1960 */ 1961 __be32 1962 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 1963 struct readdir_cd *cdp, nfsd_filldir_t func) 1964 { 1965 __be32 err; 1966 struct file *file; 1967 loff_t offset = *offsetp; 1968 int may_flags = NFSD_MAY_READ; 1969 1970 /* NFSv2 only supports 32 bit cookies */ 1971 if (rqstp->rq_vers > 2) 1972 may_flags |= NFSD_MAY_64BIT_COOKIE; 1973 1974 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file); 1975 if (err) 1976 goto out; 1977 1978 offset = vfs_llseek(file, offset, SEEK_SET); 1979 if (offset < 0) { 1980 err = nfserrno((int)offset); 1981 goto out_close; 1982 } 1983 1984 err = nfsd_buffered_readdir(file, func, cdp, offsetp); 1985 1986 if (err == nfserr_eof || err == nfserr_toosmall) 1987 err = nfs_ok; /* can still be found in ->err */ 1988 out_close: 1989 fput(file); 1990 out: 1991 return err; 1992 } 1993 1994 /* 1995 * Get file system stats 1996 * N.B. After this call fhp needs an fh_put 1997 */ 1998 __be32 1999 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) 2000 { 2001 __be32 err; 2002 2003 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); 2004 if (!err) { 2005 struct path path = { 2006 .mnt = fhp->fh_export->ex_path.mnt, 2007 .dentry = fhp->fh_dentry, 2008 }; 2009 if (vfs_statfs(&path, stat)) 2010 err = nfserr_io; 2011 } 2012 return err; 2013 } 2014 2015 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) 2016 { 2017 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; 2018 } 2019 2020 /* 2021 * Check for a user's access permissions to this inode. 2022 */ 2023 __be32 2024 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, 2025 struct dentry *dentry, int acc) 2026 { 2027 struct inode *inode = d_inode(dentry); 2028 int err; 2029 2030 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP) 2031 return 0; 2032 #if 0 2033 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 2034 acc, 2035 (acc & NFSD_MAY_READ)? " read" : "", 2036 (acc & NFSD_MAY_WRITE)? " write" : "", 2037 (acc & NFSD_MAY_EXEC)? " exec" : "", 2038 (acc & NFSD_MAY_SATTR)? " sattr" : "", 2039 (acc & NFSD_MAY_TRUNC)? " trunc" : "", 2040 (acc & NFSD_MAY_LOCK)? " lock" : "", 2041 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", 2042 inode->i_mode, 2043 IS_IMMUTABLE(inode)? " immut" : "", 2044 IS_APPEND(inode)? " append" : "", 2045 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); 2046 dprintk(" owner %d/%d user %d/%d\n", 2047 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); 2048 #endif 2049 2050 /* Normally we reject any write/sattr etc access on a read-only file 2051 * system. But if it is IRIX doing check on write-access for a 2052 * device special file, we ignore rofs. 2053 */ 2054 if (!(acc & NFSD_MAY_LOCAL_ACCESS)) 2055 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { 2056 if (exp_rdonly(rqstp, exp) || 2057 __mnt_is_readonly(exp->ex_path.mnt)) 2058 return nfserr_rofs; 2059 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) 2060 return nfserr_perm; 2061 } 2062 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) 2063 return nfserr_perm; 2064 2065 if (acc & NFSD_MAY_LOCK) { 2066 /* If we cannot rely on authentication in NLM requests, 2067 * just allow locks, otherwise require read permission, or 2068 * ownership 2069 */ 2070 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 2071 return 0; 2072 else 2073 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE; 2074 } 2075 /* 2076 * The file owner always gets access permission for accesses that 2077 * would normally be checked at open time. This is to make 2078 * file access work even when the client has done a fchmod(fd, 0). 2079 * 2080 * However, `cp foo bar' should fail nevertheless when bar is 2081 * readonly. A sensible way to do this might be to reject all 2082 * attempts to truncate a read-only file, because a creat() call 2083 * always implies file truncation. 2084 * ... but this isn't really fair. A process may reasonably call 2085 * ftruncate on an open file descriptor on a file with perm 000. 2086 * We must trust the client to do permission checking - using "ACCESS" 2087 * with NFSv3. 2088 */ 2089 if ((acc & NFSD_MAY_OWNER_OVERRIDE) && 2090 uid_eq(inode->i_uid, current_fsuid())) 2091 return 0; 2092 2093 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ 2094 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); 2095 2096 /* Allow read access to binaries even when mode 111 */ 2097 if (err == -EACCES && S_ISREG(inode->i_mode) && 2098 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) || 2099 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC))) 2100 err = inode_permission(inode, MAY_EXEC); 2101 2102 return err? nfserrno(err) : 0; 2103 } 2104