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/pagemap.h> 30 #include <linux/slab.h> 31 #include <linux/uaccess.h> 32 #include <linux/exportfs.h> 33 #include <linux/writeback.h> 34 #include <linux/security.h> 35 36 #include "xdr3.h" 37 38 #ifdef CONFIG_NFSD_V4 39 #include "../internal.h" 40 #include "acl.h" 41 #include "idmap.h" 42 #include "xdr4.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 * nfserrno - Map Linux errnos to NFS errnos 54 * @errno: POSIX(-ish) error code to be mapped 55 * 56 * Returns the appropriate (net-endian) nfserr_* (or nfs_ok if errno is 0). If 57 * it's an error we don't expect, log it once and return nfserr_io. 58 */ 59 __be32 60 nfserrno (int errno) 61 { 62 static struct { 63 __be32 nfserr; 64 int syserr; 65 } nfs_errtbl[] = { 66 { nfs_ok, 0 }, 67 { nfserr_perm, -EPERM }, 68 { nfserr_noent, -ENOENT }, 69 { nfserr_io, -EIO }, 70 { nfserr_nxio, -ENXIO }, 71 { nfserr_fbig, -E2BIG }, 72 { nfserr_stale, -EBADF }, 73 { nfserr_acces, -EACCES }, 74 { nfserr_exist, -EEXIST }, 75 { nfserr_xdev, -EXDEV }, 76 { nfserr_mlink, -EMLINK }, 77 { nfserr_nodev, -ENODEV }, 78 { nfserr_notdir, -ENOTDIR }, 79 { nfserr_isdir, -EISDIR }, 80 { nfserr_inval, -EINVAL }, 81 { nfserr_fbig, -EFBIG }, 82 { nfserr_nospc, -ENOSPC }, 83 { nfserr_rofs, -EROFS }, 84 { nfserr_mlink, -EMLINK }, 85 { nfserr_nametoolong, -ENAMETOOLONG }, 86 { nfserr_notempty, -ENOTEMPTY }, 87 { nfserr_dquot, -EDQUOT }, 88 { nfserr_stale, -ESTALE }, 89 { nfserr_jukebox, -ETIMEDOUT }, 90 { nfserr_jukebox, -ERESTARTSYS }, 91 { nfserr_jukebox, -EAGAIN }, 92 { nfserr_jukebox, -EWOULDBLOCK }, 93 { nfserr_jukebox, -ENOMEM }, 94 { nfserr_io, -ETXTBSY }, 95 { nfserr_notsupp, -EOPNOTSUPP }, 96 { nfserr_toosmall, -ETOOSMALL }, 97 { nfserr_serverfault, -ESERVERFAULT }, 98 { nfserr_serverfault, -ENFILE }, 99 { nfserr_io, -EREMOTEIO }, 100 { nfserr_stale, -EOPENSTALE }, 101 { nfserr_io, -EUCLEAN }, 102 { nfserr_perm, -ENOKEY }, 103 { nfserr_no_grace, -ENOGRACE}, 104 }; 105 int i; 106 107 for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) { 108 if (nfs_errtbl[i].syserr == errno) 109 return nfs_errtbl[i].nfserr; 110 } 111 WARN_ONCE(1, "nfsd: non-standard errno: %d\n", errno); 112 return nfserr_io; 113 } 114 115 /* 116 * Called from nfsd_lookup and encode_dirent. Check if we have crossed 117 * a mount point. 118 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged, 119 * or nfs_ok having possibly changed *dpp and *expp 120 */ 121 int 122 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, 123 struct svc_export **expp) 124 { 125 struct svc_export *exp = *expp, *exp2 = NULL; 126 struct dentry *dentry = *dpp; 127 struct path path = {.mnt = mntget(exp->ex_path.mnt), 128 .dentry = dget(dentry)}; 129 unsigned int follow_flags = 0; 130 int err = 0; 131 132 if (exp->ex_flags & NFSEXP_CROSSMOUNT) 133 follow_flags = LOOKUP_AUTOMOUNT; 134 135 err = follow_down(&path, follow_flags); 136 if (err < 0) 137 goto out; 138 if (path.mnt == exp->ex_path.mnt && path.dentry == dentry && 139 nfsd_mountpoint(dentry, exp) == 2) { 140 /* This is only a mountpoint in some other namespace */ 141 path_put(&path); 142 goto out; 143 } 144 145 exp2 = rqst_exp_get_by_name(rqstp, &path); 146 if (IS_ERR(exp2)) { 147 err = PTR_ERR(exp2); 148 /* 149 * We normally allow NFS clients to continue 150 * "underneath" a mountpoint that is not exported. 151 * The exception is V4ROOT, where no traversal is ever 152 * allowed without an explicit export of the new 153 * directory. 154 */ 155 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT)) 156 err = 0; 157 path_put(&path); 158 goto out; 159 } 160 if (nfsd_v4client(rqstp) || 161 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) { 162 /* successfully crossed mount point */ 163 /* 164 * This is subtle: path.dentry is *not* on path.mnt 165 * at this point. The only reason we are safe is that 166 * original mnt is pinned down by exp, so we should 167 * put path *before* putting exp 168 */ 169 *dpp = path.dentry; 170 path.dentry = dentry; 171 *expp = exp2; 172 exp2 = exp; 173 } 174 path_put(&path); 175 exp_put(exp2); 176 out: 177 return err; 178 } 179 180 static void follow_to_parent(struct path *path) 181 { 182 struct dentry *dp; 183 184 while (path->dentry == path->mnt->mnt_root && follow_up(path)) 185 ; 186 dp = dget_parent(path->dentry); 187 dput(path->dentry); 188 path->dentry = dp; 189 } 190 191 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp) 192 { 193 struct svc_export *exp2; 194 struct path path = {.mnt = mntget((*exp)->ex_path.mnt), 195 .dentry = dget(dparent)}; 196 197 follow_to_parent(&path); 198 199 exp2 = rqst_exp_parent(rqstp, &path); 200 if (PTR_ERR(exp2) == -ENOENT) { 201 *dentryp = dget(dparent); 202 } else if (IS_ERR(exp2)) { 203 path_put(&path); 204 return PTR_ERR(exp2); 205 } else { 206 *dentryp = dget(path.dentry); 207 exp_put(*exp); 208 *exp = exp2; 209 } 210 path_put(&path); 211 return 0; 212 } 213 214 /* 215 * For nfsd purposes, we treat V4ROOT exports as though there was an 216 * export at *every* directory. 217 * We return: 218 * '1' if this dentry *must* be an export point, 219 * '2' if it might be, if there is really a mount here, and 220 * '0' if there is no chance of an export point here. 221 */ 222 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) 223 { 224 if (!d_inode(dentry)) 225 return 0; 226 if (exp->ex_flags & NFSEXP_V4ROOT) 227 return 1; 228 if (nfsd4_is_junction(dentry)) 229 return 1; 230 if (d_managed(dentry)) 231 /* 232 * Might only be a mountpoint in a different namespace, 233 * but we need to check. 234 */ 235 return 2; 236 return 0; 237 } 238 239 __be32 240 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, 241 const char *name, unsigned int len, 242 struct svc_export **exp_ret, struct dentry **dentry_ret) 243 { 244 struct svc_export *exp; 245 struct dentry *dparent; 246 struct dentry *dentry; 247 int host_err; 248 249 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); 250 251 dparent = fhp->fh_dentry; 252 exp = exp_get(fhp->fh_export); 253 254 /* Lookup the name, but don't follow links */ 255 if (isdotent(name, len)) { 256 if (len==1) 257 dentry = dget(dparent); 258 else if (dparent != exp->ex_path.dentry) 259 dentry = dget_parent(dparent); 260 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp)) 261 dentry = dget(dparent); /* .. == . just like at / */ 262 else { 263 /* checking mountpoint crossing is very different when stepping up */ 264 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry); 265 if (host_err) 266 goto out_nfserr; 267 } 268 } else { 269 dentry = lookup_one_len_unlocked(name, dparent, len); 270 host_err = PTR_ERR(dentry); 271 if (IS_ERR(dentry)) 272 goto out_nfserr; 273 if (nfsd_mountpoint(dentry, exp)) { 274 host_err = nfsd_cross_mnt(rqstp, &dentry, &exp); 275 if (host_err) { 276 dput(dentry); 277 goto out_nfserr; 278 } 279 } 280 } 281 *dentry_ret = dentry; 282 *exp_ret = exp; 283 return 0; 284 285 out_nfserr: 286 exp_put(exp); 287 return nfserrno(host_err); 288 } 289 290 /** 291 * nfsd_lookup - look up a single path component for nfsd 292 * 293 * @rqstp: the request context 294 * @fhp: the file handle of the directory 295 * @name: the component name, or %NULL to look up parent 296 * @len: length of name to examine 297 * @resfh: pointer to pre-initialised filehandle to hold result. 298 * 299 * Look up one component of a pathname. 300 * N.B. After this call _both_ fhp and resfh need an fh_put 301 * 302 * If the lookup would cross a mountpoint, and the mounted filesystem 303 * is exported to the client with NFSEXP_NOHIDE, then the lookup is 304 * accepted as it stands and the mounted directory is 305 * returned. Otherwise the covered directory is returned. 306 * NOTE: this mountpoint crossing is not supported properly by all 307 * clients and is explicitly disallowed for NFSv3 308 * 309 */ 310 __be32 311 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, 312 unsigned int len, struct svc_fh *resfh) 313 { 314 struct svc_export *exp; 315 struct dentry *dentry; 316 __be32 err; 317 318 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); 319 if (err) 320 return err; 321 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry); 322 if (err) 323 return err; 324 err = check_nfsd_access(exp, rqstp); 325 if (err) 326 goto out; 327 /* 328 * Note: we compose the file handle now, but as the 329 * dentry may be negative, it may need to be updated. 330 */ 331 err = fh_compose(resfh, exp, dentry, fhp); 332 if (!err && d_really_is_negative(dentry)) 333 err = nfserr_noent; 334 out: 335 dput(dentry); 336 exp_put(exp); 337 return err; 338 } 339 340 /* 341 * Commit metadata changes to stable storage. 342 */ 343 static int 344 commit_inode_metadata(struct inode *inode) 345 { 346 const struct export_operations *export_ops = inode->i_sb->s_export_op; 347 348 if (export_ops->commit_metadata) 349 return export_ops->commit_metadata(inode); 350 return sync_inode_metadata(inode, 1); 351 } 352 353 static int 354 commit_metadata(struct svc_fh *fhp) 355 { 356 struct inode *inode = d_inode(fhp->fh_dentry); 357 358 if (!EX_ISSYNC(fhp->fh_export)) 359 return 0; 360 return commit_inode_metadata(inode); 361 } 362 363 /* 364 * Go over the attributes and take care of the small differences between 365 * NFS semantics and what Linux expects. 366 */ 367 static void 368 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap) 369 { 370 /* Ignore mode updates on symlinks */ 371 if (S_ISLNK(inode->i_mode)) 372 iap->ia_valid &= ~ATTR_MODE; 373 374 /* sanitize the mode change */ 375 if (iap->ia_valid & ATTR_MODE) { 376 iap->ia_mode &= S_IALLUGO; 377 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); 378 } 379 380 /* Revoke setuid/setgid on chown */ 381 if (!S_ISDIR(inode->i_mode) && 382 ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) { 383 iap->ia_valid |= ATTR_KILL_PRIV; 384 if (iap->ia_valid & ATTR_MODE) { 385 /* we're setting mode too, just clear the s*id bits */ 386 iap->ia_mode &= ~S_ISUID; 387 if (iap->ia_mode & S_IXGRP) 388 iap->ia_mode &= ~S_ISGID; 389 } else { 390 /* set ATTR_KILL_* bits and let VFS handle it */ 391 iap->ia_valid |= ATTR_KILL_SUID; 392 iap->ia_valid |= 393 setattr_should_drop_sgid(&nop_mnt_idmap, inode); 394 } 395 } 396 } 397 398 static __be32 399 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp, 400 struct iattr *iap) 401 { 402 struct inode *inode = d_inode(fhp->fh_dentry); 403 404 if (iap->ia_size < inode->i_size) { 405 __be32 err; 406 407 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, 408 NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE); 409 if (err) 410 return err; 411 } 412 return nfserrno(get_write_access(inode)); 413 } 414 415 static int __nfsd_setattr(struct dentry *dentry, struct iattr *iap) 416 { 417 int host_err; 418 419 if (iap->ia_valid & ATTR_SIZE) { 420 /* 421 * RFC5661, Section 18.30.4: 422 * Changing the size of a file with SETATTR indirectly 423 * changes the time_modify and change attributes. 424 * 425 * (and similar for the older RFCs) 426 */ 427 struct iattr size_attr = { 428 .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME, 429 .ia_size = iap->ia_size, 430 }; 431 432 if (iap->ia_size < 0) 433 return -EFBIG; 434 435 host_err = notify_change(&nop_mnt_idmap, dentry, &size_attr, NULL); 436 if (host_err) 437 return host_err; 438 iap->ia_valid &= ~ATTR_SIZE; 439 440 /* 441 * Avoid the additional setattr call below if the only other 442 * attribute that the client sends is the mtime, as we update 443 * it as part of the size change above. 444 */ 445 if ((iap->ia_valid & ~ATTR_MTIME) == 0) 446 return 0; 447 } 448 449 if (!iap->ia_valid) 450 return 0; 451 452 iap->ia_valid |= ATTR_CTIME; 453 return notify_change(&nop_mnt_idmap, dentry, iap, NULL); 454 } 455 456 /** 457 * nfsd_setattr - Set various file attributes. 458 * @rqstp: controlling RPC transaction 459 * @fhp: filehandle of target 460 * @attr: attributes to set 461 * @check_guard: set to 1 if guardtime is a valid timestamp 462 * @guardtime: do not act if ctime.tv_sec does not match this timestamp 463 * 464 * This call may adjust the contents of @attr (in particular, this 465 * call may change the bits in the na_iattr.ia_valid field). 466 * 467 * Returns nfs_ok on success, otherwise an NFS status code is 468 * returned. Caller must release @fhp by calling fh_put in either 469 * case. 470 */ 471 __be32 472 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, 473 struct nfsd_attrs *attr, 474 int check_guard, time64_t guardtime) 475 { 476 struct dentry *dentry; 477 struct inode *inode; 478 struct iattr *iap = attr->na_iattr; 479 int accmode = NFSD_MAY_SATTR; 480 umode_t ftype = 0; 481 __be32 err; 482 int host_err; 483 bool get_write_count; 484 bool size_change = (iap->ia_valid & ATTR_SIZE); 485 int retries; 486 487 if (iap->ia_valid & ATTR_SIZE) { 488 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; 489 ftype = S_IFREG; 490 } 491 492 /* 493 * If utimes(2) and friends are called with times not NULL, we should 494 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission 495 * will return EACCES, when the caller's effective UID does not match 496 * the owner of the file, and the caller is not privileged. In this 497 * situation, we should return EPERM(notify_change will return this). 498 */ 499 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) { 500 accmode |= NFSD_MAY_OWNER_OVERRIDE; 501 if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET))) 502 accmode |= NFSD_MAY_WRITE; 503 } 504 505 /* Callers that do fh_verify should do the fh_want_write: */ 506 get_write_count = !fhp->fh_dentry; 507 508 /* Get inode */ 509 err = fh_verify(rqstp, fhp, ftype, accmode); 510 if (err) 511 return err; 512 if (get_write_count) { 513 host_err = fh_want_write(fhp); 514 if (host_err) 515 goto out; 516 } 517 518 dentry = fhp->fh_dentry; 519 inode = d_inode(dentry); 520 521 nfsd_sanitize_attrs(inode, iap); 522 523 if (check_guard && guardtime != inode->i_ctime.tv_sec) 524 return nfserr_notsync; 525 526 /* 527 * The size case is special, it changes the file in addition to the 528 * attributes, and file systems don't expect it to be mixed with 529 * "random" attribute changes. We thus split out the size change 530 * into a separate call to ->setattr, and do the rest as a separate 531 * setattr call. 532 */ 533 if (size_change) { 534 err = nfsd_get_write_access(rqstp, fhp, iap); 535 if (err) 536 return err; 537 } 538 539 inode_lock(inode); 540 for (retries = 1;;) { 541 struct iattr attrs; 542 543 /* 544 * notify_change() can alter its iattr argument, making 545 * @iap unsuitable for submission multiple times. Make a 546 * copy for every loop iteration. 547 */ 548 attrs = *iap; 549 host_err = __nfsd_setattr(dentry, &attrs); 550 if (host_err != -EAGAIN || !retries--) 551 break; 552 if (!nfsd_wait_for_delegreturn(rqstp, inode)) 553 break; 554 } 555 if (attr->na_seclabel && attr->na_seclabel->len) 556 attr->na_labelerr = security_inode_setsecctx(dentry, 557 attr->na_seclabel->data, attr->na_seclabel->len); 558 if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && attr->na_pacl) 559 attr->na_aclerr = set_posix_acl(&nop_mnt_idmap, 560 dentry, ACL_TYPE_ACCESS, 561 attr->na_pacl); 562 if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && 563 !attr->na_aclerr && attr->na_dpacl && S_ISDIR(inode->i_mode)) 564 attr->na_aclerr = set_posix_acl(&nop_mnt_idmap, 565 dentry, ACL_TYPE_DEFAULT, 566 attr->na_dpacl); 567 inode_unlock(inode); 568 if (size_change) 569 put_write_access(inode); 570 out: 571 if (!host_err) 572 host_err = commit_metadata(fhp); 573 return nfserrno(host_err); 574 } 575 576 #if defined(CONFIG_NFSD_V4) 577 /* 578 * NFS junction information is stored in an extended attribute. 579 */ 580 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs" 581 582 /** 583 * nfsd4_is_junction - Test if an object could be an NFS junction 584 * 585 * @dentry: object to test 586 * 587 * Returns 1 if "dentry" appears to contain NFS junction information. 588 * Otherwise 0 is returned. 589 */ 590 int nfsd4_is_junction(struct dentry *dentry) 591 { 592 struct inode *inode = d_inode(dentry); 593 594 if (inode == NULL) 595 return 0; 596 if (inode->i_mode & S_IXUGO) 597 return 0; 598 if (!(inode->i_mode & S_ISVTX)) 599 return 0; 600 if (vfs_getxattr(&nop_mnt_idmap, dentry, NFSD_JUNCTION_XATTR_NAME, 601 NULL, 0) <= 0) 602 return 0; 603 return 1; 604 } 605 606 static struct nfsd4_compound_state *nfsd4_get_cstate(struct svc_rqst *rqstp) 607 { 608 return &((struct nfsd4_compoundres *)rqstp->rq_resp)->cstate; 609 } 610 611 __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp, 612 struct nfsd_file *nf_src, u64 src_pos, 613 struct nfsd_file *nf_dst, u64 dst_pos, 614 u64 count, bool sync) 615 { 616 struct file *src = nf_src->nf_file; 617 struct file *dst = nf_dst->nf_file; 618 errseq_t since; 619 loff_t cloned; 620 __be32 ret = 0; 621 622 since = READ_ONCE(dst->f_wb_err); 623 cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0); 624 if (cloned < 0) { 625 ret = nfserrno(cloned); 626 goto out_err; 627 } 628 if (count && cloned != count) { 629 ret = nfserrno(-EINVAL); 630 goto out_err; 631 } 632 if (sync) { 633 loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX; 634 int status = vfs_fsync_range(dst, dst_pos, dst_end, 0); 635 636 if (!status) 637 status = filemap_check_wb_err(dst->f_mapping, since); 638 if (!status) 639 status = commit_inode_metadata(file_inode(src)); 640 if (status < 0) { 641 struct nfsd_net *nn = net_generic(nf_dst->nf_net, 642 nfsd_net_id); 643 644 trace_nfsd_clone_file_range_err(rqstp, 645 &nfsd4_get_cstate(rqstp)->save_fh, 646 src_pos, 647 &nfsd4_get_cstate(rqstp)->current_fh, 648 dst_pos, 649 count, status); 650 nfsd_reset_write_verifier(nn); 651 trace_nfsd_writeverf_reset(nn, rqstp, status); 652 ret = nfserrno(status); 653 } 654 } 655 out_err: 656 return ret; 657 } 658 659 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst, 660 u64 dst_pos, u64 count) 661 { 662 ssize_t ret; 663 664 /* 665 * Limit copy to 4MB to prevent indefinitely blocking an nfsd 666 * thread and client rpc slot. The choice of 4MB is somewhat 667 * arbitrary. We might instead base this on r/wsize, or make it 668 * tunable, or use a time instead of a byte limit, or implement 669 * asynchronous copy. In theory a client could also recognize a 670 * limit like this and pipeline multiple COPY requests. 671 */ 672 count = min_t(u64, count, 1 << 22); 673 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0); 674 675 if (ret == -EOPNOTSUPP || ret == -EXDEV) 676 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 677 COPY_FILE_SPLICE); 678 return ret; 679 } 680 681 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp, 682 struct file *file, loff_t offset, loff_t len, 683 int flags) 684 { 685 int error; 686 687 if (!S_ISREG(file_inode(file)->i_mode)) 688 return nfserr_inval; 689 690 error = vfs_fallocate(file, flags, offset, len); 691 if (!error) 692 error = commit_metadata(fhp); 693 694 return nfserrno(error); 695 } 696 #endif /* defined(CONFIG_NFSD_V4) */ 697 698 /* 699 * Check server access rights to a file system object 700 */ 701 struct accessmap { 702 u32 access; 703 int how; 704 }; 705 static struct accessmap nfs3_regaccess[] = { 706 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 707 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 708 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, 709 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, 710 711 #ifdef CONFIG_NFSD_V4 712 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ }, 713 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE }, 714 { NFS4_ACCESS_XALIST, NFSD_MAY_READ }, 715 #endif 716 717 { 0, 0 } 718 }; 719 720 static struct accessmap nfs3_diraccess[] = { 721 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 722 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, 723 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, 724 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, 725 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, 726 727 #ifdef CONFIG_NFSD_V4 728 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ }, 729 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE }, 730 { NFS4_ACCESS_XALIST, NFSD_MAY_READ }, 731 #endif 732 733 { 0, 0 } 734 }; 735 736 static struct accessmap nfs3_anyaccess[] = { 737 /* Some clients - Solaris 2.6 at least, make an access call 738 * to the server to check for access for things like /dev/null 739 * (which really, the server doesn't care about). So 740 * We provide simple access checking for them, looking 741 * mainly at mode bits, and we make sure to ignore read-only 742 * filesystem checks 743 */ 744 { NFS3_ACCESS_READ, NFSD_MAY_READ }, 745 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, 746 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 747 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, 748 749 { 0, 0 } 750 }; 751 752 __be32 753 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) 754 { 755 struct accessmap *map; 756 struct svc_export *export; 757 struct dentry *dentry; 758 u32 query, result = 0, sresult = 0; 759 __be32 error; 760 761 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP); 762 if (error) 763 goto out; 764 765 export = fhp->fh_export; 766 dentry = fhp->fh_dentry; 767 768 if (d_is_reg(dentry)) 769 map = nfs3_regaccess; 770 else if (d_is_dir(dentry)) 771 map = nfs3_diraccess; 772 else 773 map = nfs3_anyaccess; 774 775 776 query = *access; 777 for (; map->access; map++) { 778 if (map->access & query) { 779 __be32 err2; 780 781 sresult |= map->access; 782 783 err2 = nfsd_permission(rqstp, export, dentry, map->how); 784 switch (err2) { 785 case nfs_ok: 786 result |= map->access; 787 break; 788 789 /* the following error codes just mean the access was not allowed, 790 * rather than an error occurred */ 791 case nfserr_rofs: 792 case nfserr_acces: 793 case nfserr_perm: 794 /* simply don't "or" in the access bit. */ 795 break; 796 default: 797 error = err2; 798 goto out; 799 } 800 } 801 } 802 *access = result; 803 if (supported) 804 *supported = sresult; 805 806 out: 807 return error; 808 } 809 810 int nfsd_open_break_lease(struct inode *inode, int access) 811 { 812 unsigned int mode; 813 814 if (access & NFSD_MAY_NOT_BREAK_LEASE) 815 return 0; 816 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY; 817 return break_lease(inode, mode | O_NONBLOCK); 818 } 819 820 /* 821 * Open an existing file or directory. 822 * The may_flags argument indicates the type of open (read/write/lock) 823 * and additional flags. 824 * N.B. After this call fhp needs an fh_put 825 */ 826 static __be32 827 __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, 828 int may_flags, struct file **filp) 829 { 830 struct path path; 831 struct inode *inode; 832 struct file *file; 833 int flags = O_RDONLY|O_LARGEFILE; 834 __be32 err; 835 int host_err = 0; 836 837 path.mnt = fhp->fh_export->ex_path.mnt; 838 path.dentry = fhp->fh_dentry; 839 inode = d_inode(path.dentry); 840 841 err = nfserr_perm; 842 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE)) 843 goto out; 844 845 if (!inode->i_fop) 846 goto out; 847 848 host_err = nfsd_open_break_lease(inode, may_flags); 849 if (host_err) /* NOMEM or WOULDBLOCK */ 850 goto out_nfserr; 851 852 if (may_flags & NFSD_MAY_WRITE) { 853 if (may_flags & NFSD_MAY_READ) 854 flags = O_RDWR|O_LARGEFILE; 855 else 856 flags = O_WRONLY|O_LARGEFILE; 857 } 858 859 file = dentry_open(&path, flags, current_cred()); 860 if (IS_ERR(file)) { 861 host_err = PTR_ERR(file); 862 goto out_nfserr; 863 } 864 865 host_err = ima_file_check(file, may_flags); 866 if (host_err) { 867 fput(file); 868 goto out_nfserr; 869 } 870 871 if (may_flags & NFSD_MAY_64BIT_COOKIE) 872 file->f_mode |= FMODE_64BITHASH; 873 else 874 file->f_mode |= FMODE_32BITHASH; 875 876 *filp = file; 877 out_nfserr: 878 err = nfserrno(host_err); 879 out: 880 return err; 881 } 882 883 __be32 884 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, 885 int may_flags, struct file **filp) 886 { 887 __be32 err; 888 bool retried = false; 889 890 validate_process_creds(); 891 /* 892 * If we get here, then the client has already done an "open", 893 * and (hopefully) checked permission - so allow OWNER_OVERRIDE 894 * in case a chmod has now revoked permission. 895 * 896 * Arguably we should also allow the owner override for 897 * directories, but we never have and it doesn't seem to have 898 * caused anyone a problem. If we were to change this, note 899 * also that our filldir callbacks would need a variant of 900 * lookup_one_len that doesn't check permissions. 901 */ 902 if (type == S_IFREG) 903 may_flags |= NFSD_MAY_OWNER_OVERRIDE; 904 retry: 905 err = fh_verify(rqstp, fhp, type, may_flags); 906 if (!err) { 907 err = __nfsd_open(rqstp, fhp, type, may_flags, filp); 908 if (err == nfserr_stale && !retried) { 909 retried = true; 910 fh_put(fhp); 911 goto retry; 912 } 913 } 914 validate_process_creds(); 915 return err; 916 } 917 918 /** 919 * nfsd_open_verified - Open a regular file for the filecache 920 * @rqstp: RPC request 921 * @fhp: NFS filehandle of the file to open 922 * @may_flags: internal permission flags 923 * @filp: OUT: open "struct file *" 924 * 925 * Returns an nfsstat value in network byte order. 926 */ 927 __be32 928 nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, int may_flags, 929 struct file **filp) 930 { 931 __be32 err; 932 933 validate_process_creds(); 934 err = __nfsd_open(rqstp, fhp, S_IFREG, may_flags, filp); 935 validate_process_creds(); 936 return err; 937 } 938 939 /* 940 * Grab and keep cached pages associated with a file in the svc_rqst 941 * so that they can be passed to the network sendmsg/sendpage routines 942 * directly. They will be released after the sending has completed. 943 * 944 * Return values: Number of bytes consumed, or -EIO if there are no 945 * remaining pages in rqstp->rq_pages. 946 */ 947 static int 948 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, 949 struct splice_desc *sd) 950 { 951 struct svc_rqst *rqstp = sd->u.data; 952 struct page *page = buf->page; // may be a compound one 953 unsigned offset = buf->offset; 954 struct page *last_page; 955 956 last_page = page + (offset + sd->len - 1) / PAGE_SIZE; 957 for (page += offset / PAGE_SIZE; page <= last_page; page++) { 958 /* 959 * Skip page replacement when extending the contents 960 * of the current page. 961 */ 962 if (page == *(rqstp->rq_next_page - 1)) 963 continue; 964 if (unlikely(!svc_rqst_replace_page(rqstp, page))) 965 return -EIO; 966 } 967 if (rqstp->rq_res.page_len == 0) // first call 968 rqstp->rq_res.page_base = offset % PAGE_SIZE; 969 rqstp->rq_res.page_len += sd->len; 970 return sd->len; 971 } 972 973 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, 974 struct splice_desc *sd) 975 { 976 return __splice_from_pipe(pipe, sd, nfsd_splice_actor); 977 } 978 979 static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len, 980 size_t expected) 981 { 982 if (expected != 0 && len == 0) 983 return 1; 984 if (offset+len >= i_size_read(file_inode(file))) 985 return 1; 986 return 0; 987 } 988 989 static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 990 struct file *file, loff_t offset, 991 unsigned long *count, u32 *eof, ssize_t host_err) 992 { 993 if (host_err >= 0) { 994 nfsd_stats_io_read_add(fhp->fh_export, host_err); 995 *eof = nfsd_eof_on_read(file, offset, host_err, *count); 996 *count = host_err; 997 fsnotify_access(file); 998 trace_nfsd_read_io_done(rqstp, fhp, offset, *count); 999 return 0; 1000 } else { 1001 trace_nfsd_read_err(rqstp, fhp, offset, host_err); 1002 return nfserrno(host_err); 1003 } 1004 } 1005 1006 /** 1007 * nfsd_splice_read - Perform a VFS read using a splice pipe 1008 * @rqstp: RPC transaction context 1009 * @fhp: file handle of file to be read 1010 * @file: opened struct file of file to be read 1011 * @offset: starting byte offset 1012 * @count: IN: requested number of bytes; OUT: number of bytes read 1013 * @eof: OUT: set non-zero if operation reached the end of the file 1014 * 1015 * Returns nfs_ok on success, otherwise an nfserr stat value is 1016 * returned. 1017 */ 1018 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 1019 struct file *file, loff_t offset, unsigned long *count, 1020 u32 *eof) 1021 { 1022 struct splice_desc sd = { 1023 .len = 0, 1024 .total_len = *count, 1025 .pos = offset, 1026 .u.data = rqstp, 1027 }; 1028 ssize_t host_err; 1029 1030 trace_nfsd_read_splice(rqstp, fhp, offset, *count); 1031 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); 1032 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err); 1033 } 1034 1035 __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp, 1036 struct file *file, loff_t offset, 1037 struct kvec *vec, int vlen, unsigned long *count, 1038 u32 *eof) 1039 { 1040 struct iov_iter iter; 1041 loff_t ppos = offset; 1042 ssize_t host_err; 1043 1044 trace_nfsd_read_vector(rqstp, fhp, offset, *count); 1045 iov_iter_kvec(&iter, ITER_DEST, vec, vlen, *count); 1046 host_err = vfs_iter_read(file, &iter, &ppos, 0); 1047 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err); 1048 } 1049 1050 /** 1051 * nfsd_iter_read - Perform a VFS read using an iterator 1052 * @rqstp: RPC transaction context 1053 * @fhp: file handle of file to be read 1054 * @file: opened struct file of file to be read 1055 * @offset: starting byte offset 1056 * @count: IN: requested number of bytes; OUT: number of bytes read 1057 * @base: offset in first page of read buffer 1058 * @eof: OUT: set non-zero if operation reached the end of the file 1059 * 1060 * Some filesystems or situations cannot use nfsd_splice_read. This 1061 * function is the slightly less-performant fallback for those cases. 1062 * 1063 * Returns nfs_ok on success, otherwise an nfserr stat value is 1064 * returned. 1065 */ 1066 __be32 nfsd_iter_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 1067 struct file *file, loff_t offset, unsigned long *count, 1068 unsigned int base, u32 *eof) 1069 { 1070 unsigned long v, total; 1071 struct iov_iter iter; 1072 loff_t ppos = offset; 1073 struct page *page; 1074 ssize_t host_err; 1075 1076 v = 0; 1077 total = *count; 1078 while (total) { 1079 page = *(rqstp->rq_next_page++); 1080 rqstp->rq_vec[v].iov_base = page_address(page) + base; 1081 rqstp->rq_vec[v].iov_len = min_t(size_t, total, PAGE_SIZE - base); 1082 total -= rqstp->rq_vec[v].iov_len; 1083 ++v; 1084 base = 0; 1085 } 1086 WARN_ON_ONCE(v > ARRAY_SIZE(rqstp->rq_vec)); 1087 1088 trace_nfsd_read_vector(rqstp, fhp, offset, *count); 1089 iov_iter_kvec(&iter, ITER_DEST, rqstp->rq_vec, v, *count); 1090 host_err = vfs_iter_read(file, &iter, &ppos, 0); 1091 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err); 1092 } 1093 1094 /* 1095 * Gathered writes: If another process is currently writing to the file, 1096 * there's a high chance this is another nfsd (triggered by a bulk write 1097 * from a client's biod). Rather than syncing the file with each write 1098 * request, we sleep for 10 msec. 1099 * 1100 * I don't know if this roughly approximates C. Juszak's idea of 1101 * gathered writes, but it's a nice and simple solution (IMHO), and it 1102 * seems to work:-) 1103 * 1104 * Note: we do this only in the NFSv2 case, since v3 and higher have a 1105 * better tool (separate unstable writes and commits) for solving this 1106 * problem. 1107 */ 1108 static int wait_for_concurrent_writes(struct file *file) 1109 { 1110 struct inode *inode = file_inode(file); 1111 static ino_t last_ino; 1112 static dev_t last_dev; 1113 int err = 0; 1114 1115 if (atomic_read(&inode->i_writecount) > 1 1116 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { 1117 dprintk("nfsd: write defer %d\n", task_pid_nr(current)); 1118 msleep(10); 1119 dprintk("nfsd: write resume %d\n", task_pid_nr(current)); 1120 } 1121 1122 if (inode->i_state & I_DIRTY) { 1123 dprintk("nfsd: write sync %d\n", task_pid_nr(current)); 1124 err = vfs_fsync(file, 0); 1125 } 1126 last_ino = inode->i_ino; 1127 last_dev = inode->i_sb->s_dev; 1128 return err; 1129 } 1130 1131 __be32 1132 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 1133 loff_t offset, struct kvec *vec, int vlen, 1134 unsigned long *cnt, int stable, 1135 __be32 *verf) 1136 { 1137 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id); 1138 struct file *file = nf->nf_file; 1139 struct super_block *sb = file_inode(file)->i_sb; 1140 struct svc_export *exp; 1141 struct iov_iter iter; 1142 errseq_t since; 1143 __be32 nfserr; 1144 int host_err; 1145 int use_wgather; 1146 loff_t pos = offset; 1147 unsigned long exp_op_flags = 0; 1148 unsigned int pflags = current->flags; 1149 rwf_t flags = 0; 1150 bool restore_flags = false; 1151 1152 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt); 1153 1154 if (sb->s_export_op) 1155 exp_op_flags = sb->s_export_op->flags; 1156 1157 if (test_bit(RQ_LOCAL, &rqstp->rq_flags) && 1158 !(exp_op_flags & EXPORT_OP_REMOTE_FS)) { 1159 /* 1160 * We want throttling in balance_dirty_pages() 1161 * and shrink_inactive_list() to only consider 1162 * the backingdev we are writing to, so that nfs to 1163 * localhost doesn't cause nfsd to lock up due to all 1164 * the client's dirty pages or its congested queue. 1165 */ 1166 current->flags |= PF_LOCAL_THROTTLE; 1167 restore_flags = true; 1168 } 1169 1170 exp = fhp->fh_export; 1171 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); 1172 1173 if (!EX_ISSYNC(exp)) 1174 stable = NFS_UNSTABLE; 1175 1176 if (stable && !use_wgather) 1177 flags |= RWF_SYNC; 1178 1179 iov_iter_kvec(&iter, ITER_SOURCE, vec, vlen, *cnt); 1180 since = READ_ONCE(file->f_wb_err); 1181 if (verf) 1182 nfsd_copy_write_verifier(verf, nn); 1183 file_start_write(file); 1184 host_err = vfs_iter_write(file, &iter, &pos, flags); 1185 file_end_write(file); 1186 if (host_err < 0) { 1187 nfsd_reset_write_verifier(nn); 1188 trace_nfsd_writeverf_reset(nn, rqstp, host_err); 1189 goto out_nfserr; 1190 } 1191 *cnt = host_err; 1192 nfsd_stats_io_write_add(exp, *cnt); 1193 fsnotify_modify(file); 1194 host_err = filemap_check_wb_err(file->f_mapping, since); 1195 if (host_err < 0) 1196 goto out_nfserr; 1197 1198 if (stable && use_wgather) { 1199 host_err = wait_for_concurrent_writes(file); 1200 if (host_err < 0) { 1201 nfsd_reset_write_verifier(nn); 1202 trace_nfsd_writeverf_reset(nn, rqstp, host_err); 1203 } 1204 } 1205 1206 out_nfserr: 1207 if (host_err >= 0) { 1208 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt); 1209 nfserr = nfs_ok; 1210 } else { 1211 trace_nfsd_write_err(rqstp, fhp, offset, host_err); 1212 nfserr = nfserrno(host_err); 1213 } 1214 if (restore_flags) 1215 current_restore_flags(pflags, PF_LOCAL_THROTTLE); 1216 return nfserr; 1217 } 1218 1219 /** 1220 * nfsd_read - Read data from a file 1221 * @rqstp: RPC transaction context 1222 * @fhp: file handle of file to be read 1223 * @offset: starting byte offset 1224 * @count: IN: requested number of bytes; OUT: number of bytes read 1225 * @eof: OUT: set non-zero if operation reached the end of the file 1226 * 1227 * The caller must verify that there is enough space in @rqstp.rq_res 1228 * to perform this operation. 1229 * 1230 * N.B. After this call fhp needs an fh_put 1231 * 1232 * Returns nfs_ok on success, otherwise an nfserr stat value is 1233 * returned. 1234 */ 1235 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, 1236 loff_t offset, unsigned long *count, u32 *eof) 1237 { 1238 struct nfsd_file *nf; 1239 struct file *file; 1240 __be32 err; 1241 1242 trace_nfsd_read_start(rqstp, fhp, offset, *count); 1243 err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_READ, &nf); 1244 if (err) 1245 return err; 1246 1247 file = nf->nf_file; 1248 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags)) 1249 err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof); 1250 else 1251 err = nfsd_iter_read(rqstp, fhp, file, offset, count, 0, eof); 1252 1253 nfsd_file_put(nf); 1254 trace_nfsd_read_done(rqstp, fhp, offset, *count); 1255 return err; 1256 } 1257 1258 /* 1259 * Write data to a file. 1260 * The stable flag requests synchronous writes. 1261 * N.B. After this call fhp needs an fh_put 1262 */ 1263 __be32 1264 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, 1265 struct kvec *vec, int vlen, unsigned long *cnt, int stable, 1266 __be32 *verf) 1267 { 1268 struct nfsd_file *nf; 1269 __be32 err; 1270 1271 trace_nfsd_write_start(rqstp, fhp, offset, *cnt); 1272 1273 err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_WRITE, &nf); 1274 if (err) 1275 goto out; 1276 1277 err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec, 1278 vlen, cnt, stable, verf); 1279 nfsd_file_put(nf); 1280 out: 1281 trace_nfsd_write_done(rqstp, fhp, offset, *cnt); 1282 return err; 1283 } 1284 1285 /** 1286 * nfsd_commit - Commit pending writes to stable storage 1287 * @rqstp: RPC request being processed 1288 * @fhp: NFS filehandle 1289 * @nf: target file 1290 * @offset: raw offset from beginning of file 1291 * @count: raw count of bytes to sync 1292 * @verf: filled in with the server's current write verifier 1293 * 1294 * Note: we guarantee that data that lies within the range specified 1295 * by the 'offset' and 'count' parameters will be synced. The server 1296 * is permitted to sync data that lies outside this range at the 1297 * same time. 1298 * 1299 * Unfortunately we cannot lock the file to make sure we return full WCC 1300 * data to the client, as locking happens lower down in the filesystem. 1301 * 1302 * Return values: 1303 * An nfsstat value in network byte order. 1304 */ 1305 __be32 1306 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf, 1307 u64 offset, u32 count, __be32 *verf) 1308 { 1309 __be32 err = nfs_ok; 1310 u64 maxbytes; 1311 loff_t start, end; 1312 struct nfsd_net *nn; 1313 1314 /* 1315 * Convert the client-provided (offset, count) range to a 1316 * (start, end) range. If the client-provided range falls 1317 * outside the maximum file size of the underlying FS, 1318 * clamp the sync range appropriately. 1319 */ 1320 start = 0; 1321 end = LLONG_MAX; 1322 maxbytes = (u64)fhp->fh_dentry->d_sb->s_maxbytes; 1323 if (offset < maxbytes) { 1324 start = offset; 1325 if (count && (offset + count - 1 < maxbytes)) 1326 end = offset + count - 1; 1327 } 1328 1329 nn = net_generic(nf->nf_net, nfsd_net_id); 1330 if (EX_ISSYNC(fhp->fh_export)) { 1331 errseq_t since = READ_ONCE(nf->nf_file->f_wb_err); 1332 int err2; 1333 1334 err2 = vfs_fsync_range(nf->nf_file, start, end, 0); 1335 switch (err2) { 1336 case 0: 1337 nfsd_copy_write_verifier(verf, nn); 1338 err2 = filemap_check_wb_err(nf->nf_file->f_mapping, 1339 since); 1340 err = nfserrno(err2); 1341 break; 1342 case -EINVAL: 1343 err = nfserr_notsupp; 1344 break; 1345 default: 1346 nfsd_reset_write_verifier(nn); 1347 trace_nfsd_writeverf_reset(nn, rqstp, err2); 1348 err = nfserrno(err2); 1349 } 1350 } else 1351 nfsd_copy_write_verifier(verf, nn); 1352 1353 return err; 1354 } 1355 1356 /** 1357 * nfsd_create_setattr - Set a created file's attributes 1358 * @rqstp: RPC transaction being executed 1359 * @fhp: NFS filehandle of parent directory 1360 * @resfhp: NFS filehandle of new object 1361 * @attrs: requested attributes of new object 1362 * 1363 * Returns nfs_ok on success, or an nfsstat in network byte order. 1364 */ 1365 __be32 1366 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, 1367 struct svc_fh *resfhp, struct nfsd_attrs *attrs) 1368 { 1369 struct iattr *iap = attrs->na_iattr; 1370 __be32 status; 1371 1372 /* 1373 * Mode has already been set by file creation. 1374 */ 1375 iap->ia_valid &= ~ATTR_MODE; 1376 1377 /* 1378 * Setting uid/gid works only for root. Irix appears to 1379 * send along the gid on create when it tries to implement 1380 * setgid directories via NFS: 1381 */ 1382 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID)) 1383 iap->ia_valid &= ~(ATTR_UID|ATTR_GID); 1384 1385 /* 1386 * Callers expect new file metadata to be committed even 1387 * if the attributes have not changed. 1388 */ 1389 if (iap->ia_valid) 1390 status = nfsd_setattr(rqstp, resfhp, attrs, 0, (time64_t)0); 1391 else 1392 status = nfserrno(commit_metadata(resfhp)); 1393 1394 /* 1395 * Transactional filesystems had a chance to commit changes 1396 * for both parent and child simultaneously making the 1397 * following commit_metadata a noop in many cases. 1398 */ 1399 if (!status) 1400 status = nfserrno(commit_metadata(fhp)); 1401 1402 /* 1403 * Update the new filehandle to pick up the new attributes. 1404 */ 1405 if (!status) 1406 status = fh_update(resfhp); 1407 1408 return status; 1409 } 1410 1411 /* HPUX client sometimes creates a file in mode 000, and sets size to 0. 1412 * setting size to 0 may fail for some specific file systems by the permission 1413 * checking which requires WRITE permission but the mode is 000. 1414 * we ignore the resizing(to 0) on the just new created file, since the size is 1415 * 0 after file created. 1416 * 1417 * call this only after vfs_create() is called. 1418 * */ 1419 static void 1420 nfsd_check_ignore_resizing(struct iattr *iap) 1421 { 1422 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) 1423 iap->ia_valid &= ~ATTR_SIZE; 1424 } 1425 1426 /* The parent directory should already be locked: */ 1427 __be32 1428 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp, 1429 struct nfsd_attrs *attrs, 1430 int type, dev_t rdev, struct svc_fh *resfhp) 1431 { 1432 struct dentry *dentry, *dchild; 1433 struct inode *dirp; 1434 struct iattr *iap = attrs->na_iattr; 1435 __be32 err; 1436 int host_err; 1437 1438 dentry = fhp->fh_dentry; 1439 dirp = d_inode(dentry); 1440 1441 dchild = dget(resfhp->fh_dentry); 1442 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE); 1443 if (err) 1444 goto out; 1445 1446 if (!(iap->ia_valid & ATTR_MODE)) 1447 iap->ia_mode = 0; 1448 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; 1449 1450 if (!IS_POSIXACL(dirp)) 1451 iap->ia_mode &= ~current_umask(); 1452 1453 err = 0; 1454 switch (type) { 1455 case S_IFREG: 1456 host_err = vfs_create(&nop_mnt_idmap, dirp, dchild, 1457 iap->ia_mode, true); 1458 if (!host_err) 1459 nfsd_check_ignore_resizing(iap); 1460 break; 1461 case S_IFDIR: 1462 host_err = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode); 1463 if (!host_err && unlikely(d_unhashed(dchild))) { 1464 struct dentry *d; 1465 d = lookup_one_len(dchild->d_name.name, 1466 dchild->d_parent, 1467 dchild->d_name.len); 1468 if (IS_ERR(d)) { 1469 host_err = PTR_ERR(d); 1470 break; 1471 } 1472 if (unlikely(d_is_negative(d))) { 1473 dput(d); 1474 err = nfserr_serverfault; 1475 goto out; 1476 } 1477 dput(resfhp->fh_dentry); 1478 resfhp->fh_dentry = dget(d); 1479 err = fh_update(resfhp); 1480 dput(dchild); 1481 dchild = d; 1482 if (err) 1483 goto out; 1484 } 1485 break; 1486 case S_IFCHR: 1487 case S_IFBLK: 1488 case S_IFIFO: 1489 case S_IFSOCK: 1490 host_err = vfs_mknod(&nop_mnt_idmap, dirp, dchild, 1491 iap->ia_mode, rdev); 1492 break; 1493 default: 1494 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", 1495 type); 1496 host_err = -EINVAL; 1497 } 1498 if (host_err < 0) 1499 goto out_nfserr; 1500 1501 err = nfsd_create_setattr(rqstp, fhp, resfhp, attrs); 1502 1503 out: 1504 dput(dchild); 1505 return err; 1506 1507 out_nfserr: 1508 err = nfserrno(host_err); 1509 goto out; 1510 } 1511 1512 /* 1513 * Create a filesystem object (regular, directory, special). 1514 * Note that the parent directory is left locked. 1515 * 1516 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp 1517 */ 1518 __be32 1519 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, 1520 char *fname, int flen, struct nfsd_attrs *attrs, 1521 int type, dev_t rdev, struct svc_fh *resfhp) 1522 { 1523 struct dentry *dentry, *dchild = NULL; 1524 __be32 err; 1525 int host_err; 1526 1527 if (isdotent(fname, flen)) 1528 return nfserr_exist; 1529 1530 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP); 1531 if (err) 1532 return err; 1533 1534 dentry = fhp->fh_dentry; 1535 1536 host_err = fh_want_write(fhp); 1537 if (host_err) 1538 return nfserrno(host_err); 1539 1540 inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT); 1541 dchild = lookup_one_len(fname, dentry, flen); 1542 host_err = PTR_ERR(dchild); 1543 if (IS_ERR(dchild)) { 1544 err = nfserrno(host_err); 1545 goto out_unlock; 1546 } 1547 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); 1548 /* 1549 * We unconditionally drop our ref to dchild as fh_compose will have 1550 * already grabbed its own ref for it. 1551 */ 1552 dput(dchild); 1553 if (err) 1554 goto out_unlock; 1555 fh_fill_pre_attrs(fhp); 1556 err = nfsd_create_locked(rqstp, fhp, attrs, type, rdev, resfhp); 1557 fh_fill_post_attrs(fhp); 1558 out_unlock: 1559 inode_unlock(dentry->d_inode); 1560 return err; 1561 } 1562 1563 /* 1564 * Read a symlink. On entry, *lenp must contain the maximum path length that 1565 * fits into the buffer. On return, it contains the true length. 1566 * N.B. After this call fhp needs an fh_put 1567 */ 1568 __be32 1569 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) 1570 { 1571 __be32 err; 1572 const char *link; 1573 struct path path; 1574 DEFINE_DELAYED_CALL(done); 1575 int len; 1576 1577 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); 1578 if (unlikely(err)) 1579 return err; 1580 1581 path.mnt = fhp->fh_export->ex_path.mnt; 1582 path.dentry = fhp->fh_dentry; 1583 1584 if (unlikely(!d_is_symlink(path.dentry))) 1585 return nfserr_inval; 1586 1587 touch_atime(&path); 1588 1589 link = vfs_get_link(path.dentry, &done); 1590 if (IS_ERR(link)) 1591 return nfserrno(PTR_ERR(link)); 1592 1593 len = strlen(link); 1594 if (len < *lenp) 1595 *lenp = len; 1596 memcpy(buf, link, *lenp); 1597 do_delayed_call(&done); 1598 return 0; 1599 } 1600 1601 /** 1602 * nfsd_symlink - Create a symlink and look up its inode 1603 * @rqstp: RPC transaction being executed 1604 * @fhp: NFS filehandle of parent directory 1605 * @fname: filename of the new symlink 1606 * @flen: length of @fname 1607 * @path: content of the new symlink (NUL-terminated) 1608 * @attrs: requested attributes of new object 1609 * @resfhp: NFS filehandle of new object 1610 * 1611 * N.B. After this call _both_ fhp and resfhp need an fh_put 1612 * 1613 * Returns nfs_ok on success, or an nfsstat in network byte order. 1614 */ 1615 __be32 1616 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, 1617 char *fname, int flen, 1618 char *path, struct nfsd_attrs *attrs, 1619 struct svc_fh *resfhp) 1620 { 1621 struct dentry *dentry, *dnew; 1622 __be32 err, cerr; 1623 int host_err; 1624 1625 err = nfserr_noent; 1626 if (!flen || path[0] == '\0') 1627 goto out; 1628 err = nfserr_exist; 1629 if (isdotent(fname, flen)) 1630 goto out; 1631 1632 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); 1633 if (err) 1634 goto out; 1635 1636 host_err = fh_want_write(fhp); 1637 if (host_err) { 1638 err = nfserrno(host_err); 1639 goto out; 1640 } 1641 1642 dentry = fhp->fh_dentry; 1643 inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT); 1644 dnew = lookup_one_len(fname, dentry, flen); 1645 if (IS_ERR(dnew)) { 1646 err = nfserrno(PTR_ERR(dnew)); 1647 inode_unlock(dentry->d_inode); 1648 goto out_drop_write; 1649 } 1650 fh_fill_pre_attrs(fhp); 1651 host_err = vfs_symlink(&nop_mnt_idmap, d_inode(dentry), dnew, path); 1652 err = nfserrno(host_err); 1653 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); 1654 if (!err) 1655 nfsd_create_setattr(rqstp, fhp, resfhp, attrs); 1656 fh_fill_post_attrs(fhp); 1657 inode_unlock(dentry->d_inode); 1658 if (!err) 1659 err = nfserrno(commit_metadata(fhp)); 1660 dput(dnew); 1661 if (err==0) err = cerr; 1662 out_drop_write: 1663 fh_drop_write(fhp); 1664 out: 1665 return err; 1666 } 1667 1668 /* 1669 * Create a hardlink 1670 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1671 */ 1672 __be32 1673 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, 1674 char *name, int len, struct svc_fh *tfhp) 1675 { 1676 struct dentry *ddir, *dnew, *dold; 1677 struct inode *dirp; 1678 __be32 err; 1679 int host_err; 1680 1681 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); 1682 if (err) 1683 goto out; 1684 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP); 1685 if (err) 1686 goto out; 1687 err = nfserr_isdir; 1688 if (d_is_dir(tfhp->fh_dentry)) 1689 goto out; 1690 err = nfserr_perm; 1691 if (!len) 1692 goto out; 1693 err = nfserr_exist; 1694 if (isdotent(name, len)) 1695 goto out; 1696 1697 host_err = fh_want_write(tfhp); 1698 if (host_err) { 1699 err = nfserrno(host_err); 1700 goto out; 1701 } 1702 1703 ddir = ffhp->fh_dentry; 1704 dirp = d_inode(ddir); 1705 inode_lock_nested(dirp, I_MUTEX_PARENT); 1706 1707 dnew = lookup_one_len(name, ddir, len); 1708 if (IS_ERR(dnew)) { 1709 err = nfserrno(PTR_ERR(dnew)); 1710 goto out_unlock; 1711 } 1712 1713 dold = tfhp->fh_dentry; 1714 1715 err = nfserr_noent; 1716 if (d_really_is_negative(dold)) 1717 goto out_dput; 1718 fh_fill_pre_attrs(ffhp); 1719 host_err = vfs_link(dold, &nop_mnt_idmap, dirp, dnew, NULL); 1720 fh_fill_post_attrs(ffhp); 1721 inode_unlock(dirp); 1722 if (!host_err) { 1723 err = nfserrno(commit_metadata(ffhp)); 1724 if (!err) 1725 err = nfserrno(commit_metadata(tfhp)); 1726 } else { 1727 if (host_err == -EXDEV && rqstp->rq_vers == 2) 1728 err = nfserr_acces; 1729 else 1730 err = nfserrno(host_err); 1731 } 1732 dput(dnew); 1733 out_drop_write: 1734 fh_drop_write(tfhp); 1735 out: 1736 return err; 1737 1738 out_dput: 1739 dput(dnew); 1740 out_unlock: 1741 inode_unlock(dirp); 1742 goto out_drop_write; 1743 } 1744 1745 static void 1746 nfsd_close_cached_files(struct dentry *dentry) 1747 { 1748 struct inode *inode = d_inode(dentry); 1749 1750 if (inode && S_ISREG(inode->i_mode)) 1751 nfsd_file_close_inode_sync(inode); 1752 } 1753 1754 static bool 1755 nfsd_has_cached_files(struct dentry *dentry) 1756 { 1757 bool ret = false; 1758 struct inode *inode = d_inode(dentry); 1759 1760 if (inode && S_ISREG(inode->i_mode)) 1761 ret = nfsd_file_is_cached(inode); 1762 return ret; 1763 } 1764 1765 /* 1766 * Rename a file 1767 * N.B. After this call _both_ ffhp and tfhp need an fh_put 1768 */ 1769 __be32 1770 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, 1771 struct svc_fh *tfhp, char *tname, int tlen) 1772 { 1773 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap; 1774 struct inode *fdir, *tdir; 1775 __be32 err; 1776 int host_err; 1777 bool close_cached = false; 1778 1779 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); 1780 if (err) 1781 goto out; 1782 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE); 1783 if (err) 1784 goto out; 1785 1786 fdentry = ffhp->fh_dentry; 1787 fdir = d_inode(fdentry); 1788 1789 tdentry = tfhp->fh_dentry; 1790 tdir = d_inode(tdentry); 1791 1792 err = nfserr_perm; 1793 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 1794 goto out; 1795 1796 retry: 1797 host_err = fh_want_write(ffhp); 1798 if (host_err) { 1799 err = nfserrno(host_err); 1800 goto out; 1801 } 1802 1803 trap = lock_rename(tdentry, fdentry); 1804 fh_fill_pre_attrs(ffhp); 1805 fh_fill_pre_attrs(tfhp); 1806 1807 odentry = lookup_one_len(fname, fdentry, flen); 1808 host_err = PTR_ERR(odentry); 1809 if (IS_ERR(odentry)) 1810 goto out_nfserr; 1811 1812 host_err = -ENOENT; 1813 if (d_really_is_negative(odentry)) 1814 goto out_dput_old; 1815 host_err = -EINVAL; 1816 if (odentry == trap) 1817 goto out_dput_old; 1818 1819 ndentry = lookup_one_len(tname, tdentry, tlen); 1820 host_err = PTR_ERR(ndentry); 1821 if (IS_ERR(ndentry)) 1822 goto out_dput_old; 1823 host_err = -ENOTEMPTY; 1824 if (ndentry == trap) 1825 goto out_dput_new; 1826 1827 host_err = -EXDEV; 1828 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) 1829 goto out_dput_new; 1830 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry) 1831 goto out_dput_new; 1832 1833 if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) && 1834 nfsd_has_cached_files(ndentry)) { 1835 close_cached = true; 1836 goto out_dput_old; 1837 } else { 1838 struct renamedata rd = { 1839 .old_mnt_idmap = &nop_mnt_idmap, 1840 .old_dir = fdir, 1841 .old_dentry = odentry, 1842 .new_mnt_idmap = &nop_mnt_idmap, 1843 .new_dir = tdir, 1844 .new_dentry = ndentry, 1845 }; 1846 int retries; 1847 1848 for (retries = 1;;) { 1849 host_err = vfs_rename(&rd); 1850 if (host_err != -EAGAIN || !retries--) 1851 break; 1852 if (!nfsd_wait_for_delegreturn(rqstp, d_inode(odentry))) 1853 break; 1854 } 1855 if (!host_err) { 1856 host_err = commit_metadata(tfhp); 1857 if (!host_err) 1858 host_err = commit_metadata(ffhp); 1859 } 1860 } 1861 out_dput_new: 1862 dput(ndentry); 1863 out_dput_old: 1864 dput(odentry); 1865 out_nfserr: 1866 err = nfserrno(host_err); 1867 1868 if (!close_cached) { 1869 fh_fill_post_attrs(ffhp); 1870 fh_fill_post_attrs(tfhp); 1871 } 1872 unlock_rename(tdentry, fdentry); 1873 fh_drop_write(ffhp); 1874 1875 /* 1876 * If the target dentry has cached open files, then we need to try to 1877 * close them prior to doing the rename. Flushing delayed fput 1878 * shouldn't be done with locks held however, so we delay it until this 1879 * point and then reattempt the whole shebang. 1880 */ 1881 if (close_cached) { 1882 close_cached = false; 1883 nfsd_close_cached_files(ndentry); 1884 dput(ndentry); 1885 goto retry; 1886 } 1887 out: 1888 return err; 1889 } 1890 1891 /* 1892 * Unlink a file or directory 1893 * N.B. After this call fhp needs an fh_put 1894 */ 1895 __be32 1896 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, 1897 char *fname, int flen) 1898 { 1899 struct dentry *dentry, *rdentry; 1900 struct inode *dirp; 1901 struct inode *rinode; 1902 __be32 err; 1903 int host_err; 1904 1905 err = nfserr_acces; 1906 if (!flen || isdotent(fname, flen)) 1907 goto out; 1908 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); 1909 if (err) 1910 goto out; 1911 1912 host_err = fh_want_write(fhp); 1913 if (host_err) 1914 goto out_nfserr; 1915 1916 dentry = fhp->fh_dentry; 1917 dirp = d_inode(dentry); 1918 inode_lock_nested(dirp, I_MUTEX_PARENT); 1919 1920 rdentry = lookup_one_len(fname, dentry, flen); 1921 host_err = PTR_ERR(rdentry); 1922 if (IS_ERR(rdentry)) 1923 goto out_unlock; 1924 1925 if (d_really_is_negative(rdentry)) { 1926 dput(rdentry); 1927 host_err = -ENOENT; 1928 goto out_unlock; 1929 } 1930 rinode = d_inode(rdentry); 1931 ihold(rinode); 1932 1933 if (!type) 1934 type = d_inode(rdentry)->i_mode & S_IFMT; 1935 1936 fh_fill_pre_attrs(fhp); 1937 if (type != S_IFDIR) { 1938 int retries; 1939 1940 if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) 1941 nfsd_close_cached_files(rdentry); 1942 1943 for (retries = 1;;) { 1944 host_err = vfs_unlink(&nop_mnt_idmap, dirp, rdentry, NULL); 1945 if (host_err != -EAGAIN || !retries--) 1946 break; 1947 if (!nfsd_wait_for_delegreturn(rqstp, rinode)) 1948 break; 1949 } 1950 } else { 1951 host_err = vfs_rmdir(&nop_mnt_idmap, dirp, rdentry); 1952 } 1953 fh_fill_post_attrs(fhp); 1954 1955 inode_unlock(dirp); 1956 if (!host_err) 1957 host_err = commit_metadata(fhp); 1958 dput(rdentry); 1959 iput(rinode); /* truncate the inode here */ 1960 1961 out_drop_write: 1962 fh_drop_write(fhp); 1963 out_nfserr: 1964 if (host_err == -EBUSY) { 1965 /* name is mounted-on. There is no perfect 1966 * error status. 1967 */ 1968 if (nfsd_v4client(rqstp)) 1969 err = nfserr_file_open; 1970 else 1971 err = nfserr_acces; 1972 } else { 1973 err = nfserrno(host_err); 1974 } 1975 out: 1976 return err; 1977 out_unlock: 1978 inode_unlock(dirp); 1979 goto out_drop_write; 1980 } 1981 1982 /* 1983 * We do this buffering because we must not call back into the file 1984 * system's ->lookup() method from the filldir callback. That may well 1985 * deadlock a number of file systems. 1986 * 1987 * This is based heavily on the implementation of same in XFS. 1988 */ 1989 struct buffered_dirent { 1990 u64 ino; 1991 loff_t offset; 1992 int namlen; 1993 unsigned int d_type; 1994 char name[]; 1995 }; 1996 1997 struct readdir_data { 1998 struct dir_context ctx; 1999 char *dirent; 2000 size_t used; 2001 int full; 2002 }; 2003 2004 static bool nfsd_buffered_filldir(struct dir_context *ctx, const char *name, 2005 int namlen, loff_t offset, u64 ino, 2006 unsigned int d_type) 2007 { 2008 struct readdir_data *buf = 2009 container_of(ctx, struct readdir_data, ctx); 2010 struct buffered_dirent *de = (void *)(buf->dirent + buf->used); 2011 unsigned int reclen; 2012 2013 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); 2014 if (buf->used + reclen > PAGE_SIZE) { 2015 buf->full = 1; 2016 return false; 2017 } 2018 2019 de->namlen = namlen; 2020 de->offset = offset; 2021 de->ino = ino; 2022 de->d_type = d_type; 2023 memcpy(de->name, name, namlen); 2024 buf->used += reclen; 2025 2026 return true; 2027 } 2028 2029 static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp, 2030 nfsd_filldir_t func, struct readdir_cd *cdp, 2031 loff_t *offsetp) 2032 { 2033 struct buffered_dirent *de; 2034 int host_err; 2035 int size; 2036 loff_t offset; 2037 struct readdir_data buf = { 2038 .ctx.actor = nfsd_buffered_filldir, 2039 .dirent = (void *)__get_free_page(GFP_KERNEL) 2040 }; 2041 2042 if (!buf.dirent) 2043 return nfserrno(-ENOMEM); 2044 2045 offset = *offsetp; 2046 2047 while (1) { 2048 unsigned int reclen; 2049 2050 cdp->err = nfserr_eof; /* will be cleared on successful read */ 2051 buf.used = 0; 2052 buf.full = 0; 2053 2054 host_err = iterate_dir(file, &buf.ctx); 2055 if (buf.full) 2056 host_err = 0; 2057 2058 if (host_err < 0) 2059 break; 2060 2061 size = buf.used; 2062 2063 if (!size) 2064 break; 2065 2066 de = (struct buffered_dirent *)buf.dirent; 2067 while (size > 0) { 2068 offset = de->offset; 2069 2070 if (func(cdp, de->name, de->namlen, de->offset, 2071 de->ino, de->d_type)) 2072 break; 2073 2074 if (cdp->err != nfs_ok) 2075 break; 2076 2077 trace_nfsd_dirent(fhp, de->ino, de->name, de->namlen); 2078 2079 reclen = ALIGN(sizeof(*de) + de->namlen, 2080 sizeof(u64)); 2081 size -= reclen; 2082 de = (struct buffered_dirent *)((char *)de + reclen); 2083 } 2084 if (size > 0) /* We bailed out early */ 2085 break; 2086 2087 offset = vfs_llseek(file, 0, SEEK_CUR); 2088 } 2089 2090 free_page((unsigned long)(buf.dirent)); 2091 2092 if (host_err) 2093 return nfserrno(host_err); 2094 2095 *offsetp = offset; 2096 return cdp->err; 2097 } 2098 2099 /* 2100 * Read entries from a directory. 2101 * The NFSv3/4 verifier we ignore for now. 2102 */ 2103 __be32 2104 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, 2105 struct readdir_cd *cdp, nfsd_filldir_t func) 2106 { 2107 __be32 err; 2108 struct file *file; 2109 loff_t offset = *offsetp; 2110 int may_flags = NFSD_MAY_READ; 2111 2112 /* NFSv2 only supports 32 bit cookies */ 2113 if (rqstp->rq_vers > 2) 2114 may_flags |= NFSD_MAY_64BIT_COOKIE; 2115 2116 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file); 2117 if (err) 2118 goto out; 2119 2120 offset = vfs_llseek(file, offset, SEEK_SET); 2121 if (offset < 0) { 2122 err = nfserrno((int)offset); 2123 goto out_close; 2124 } 2125 2126 err = nfsd_buffered_readdir(file, fhp, func, cdp, offsetp); 2127 2128 if (err == nfserr_eof || err == nfserr_toosmall) 2129 err = nfs_ok; /* can still be found in ->err */ 2130 out_close: 2131 fput(file); 2132 out: 2133 return err; 2134 } 2135 2136 /* 2137 * Get file system stats 2138 * N.B. After this call fhp needs an fh_put 2139 */ 2140 __be32 2141 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) 2142 { 2143 __be32 err; 2144 2145 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); 2146 if (!err) { 2147 struct path path = { 2148 .mnt = fhp->fh_export->ex_path.mnt, 2149 .dentry = fhp->fh_dentry, 2150 }; 2151 if (vfs_statfs(&path, stat)) 2152 err = nfserr_io; 2153 } 2154 return err; 2155 } 2156 2157 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) 2158 { 2159 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; 2160 } 2161 2162 #ifdef CONFIG_NFSD_V4 2163 /* 2164 * Helper function to translate error numbers. In the case of xattr operations, 2165 * some error codes need to be translated outside of the standard translations. 2166 * 2167 * ENODATA needs to be translated to nfserr_noxattr. 2168 * E2BIG to nfserr_xattr2big. 2169 * 2170 * Additionally, vfs_listxattr can return -ERANGE. This means that the 2171 * file has too many extended attributes to retrieve inside an 2172 * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation: 2173 * filesystems will allow the adding of extended attributes until they hit 2174 * their own internal limit. This limit may be larger than XATTR_LIST_MAX. 2175 * So, at that point, the attributes are present and valid, but can't 2176 * be retrieved using listxattr, since the upper level xattr code enforces 2177 * the XATTR_LIST_MAX limit. 2178 * 2179 * This bug means that we need to deal with listxattr returning -ERANGE. The 2180 * best mapping is to return TOOSMALL. 2181 */ 2182 static __be32 2183 nfsd_xattr_errno(int err) 2184 { 2185 switch (err) { 2186 case -ENODATA: 2187 return nfserr_noxattr; 2188 case -E2BIG: 2189 return nfserr_xattr2big; 2190 case -ERANGE: 2191 return nfserr_toosmall; 2192 } 2193 return nfserrno(err); 2194 } 2195 2196 /* 2197 * Retrieve the specified user extended attribute. To avoid always 2198 * having to allocate the maximum size (since we are not getting 2199 * a maximum size from the RPC), do a probe + alloc. Hold a reader 2200 * lock on i_rwsem to prevent the extended attribute from changing 2201 * size while we're doing this. 2202 */ 2203 __be32 2204 nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name, 2205 void **bufp, int *lenp) 2206 { 2207 ssize_t len; 2208 __be32 err; 2209 char *buf; 2210 struct inode *inode; 2211 struct dentry *dentry; 2212 2213 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ); 2214 if (err) 2215 return err; 2216 2217 err = nfs_ok; 2218 dentry = fhp->fh_dentry; 2219 inode = d_inode(dentry); 2220 2221 inode_lock_shared(inode); 2222 2223 len = vfs_getxattr(&nop_mnt_idmap, dentry, name, NULL, 0); 2224 2225 /* 2226 * Zero-length attribute, just return. 2227 */ 2228 if (len == 0) { 2229 *bufp = NULL; 2230 *lenp = 0; 2231 goto out; 2232 } 2233 2234 if (len < 0) { 2235 err = nfsd_xattr_errno(len); 2236 goto out; 2237 } 2238 2239 if (len > *lenp) { 2240 err = nfserr_toosmall; 2241 goto out; 2242 } 2243 2244 buf = kvmalloc(len, GFP_KERNEL); 2245 if (buf == NULL) { 2246 err = nfserr_jukebox; 2247 goto out; 2248 } 2249 2250 len = vfs_getxattr(&nop_mnt_idmap, dentry, name, buf, len); 2251 if (len <= 0) { 2252 kvfree(buf); 2253 buf = NULL; 2254 err = nfsd_xattr_errno(len); 2255 } 2256 2257 *lenp = len; 2258 *bufp = buf; 2259 2260 out: 2261 inode_unlock_shared(inode); 2262 2263 return err; 2264 } 2265 2266 /* 2267 * Retrieve the xattr names. Since we can't know how many are 2268 * user extended attributes, we must get all attributes here, 2269 * and have the XDR encode filter out the "user." ones. 2270 * 2271 * While this could always just allocate an XATTR_LIST_MAX 2272 * buffer, that's a waste, so do a probe + allocate. To 2273 * avoid any changes between the probe and allocate, wrap 2274 * this in inode_lock. 2275 */ 2276 __be32 2277 nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp, 2278 int *lenp) 2279 { 2280 ssize_t len; 2281 __be32 err; 2282 char *buf; 2283 struct inode *inode; 2284 struct dentry *dentry; 2285 2286 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ); 2287 if (err) 2288 return err; 2289 2290 dentry = fhp->fh_dentry; 2291 inode = d_inode(dentry); 2292 *lenp = 0; 2293 2294 inode_lock_shared(inode); 2295 2296 len = vfs_listxattr(dentry, NULL, 0); 2297 if (len <= 0) { 2298 err = nfsd_xattr_errno(len); 2299 goto out; 2300 } 2301 2302 if (len > XATTR_LIST_MAX) { 2303 err = nfserr_xattr2big; 2304 goto out; 2305 } 2306 2307 buf = kvmalloc(len, GFP_KERNEL); 2308 if (buf == NULL) { 2309 err = nfserr_jukebox; 2310 goto out; 2311 } 2312 2313 len = vfs_listxattr(dentry, buf, len); 2314 if (len <= 0) { 2315 kvfree(buf); 2316 err = nfsd_xattr_errno(len); 2317 goto out; 2318 } 2319 2320 *lenp = len; 2321 *bufp = buf; 2322 2323 err = nfs_ok; 2324 out: 2325 inode_unlock_shared(inode); 2326 2327 return err; 2328 } 2329 2330 /** 2331 * nfsd_removexattr - Remove an extended attribute 2332 * @rqstp: RPC transaction being executed 2333 * @fhp: NFS filehandle of object with xattr to remove 2334 * @name: name of xattr to remove (NUL-terminate) 2335 * 2336 * Pass in a NULL pointer for delegated_inode, and let the client deal 2337 * with NFS4ERR_DELAY (same as with e.g. setattr and remove). 2338 * 2339 * Returns nfs_ok on success, or an nfsstat in network byte order. 2340 */ 2341 __be32 2342 nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name) 2343 { 2344 __be32 err; 2345 int ret; 2346 2347 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE); 2348 if (err) 2349 return err; 2350 2351 ret = fh_want_write(fhp); 2352 if (ret) 2353 return nfserrno(ret); 2354 2355 inode_lock(fhp->fh_dentry->d_inode); 2356 fh_fill_pre_attrs(fhp); 2357 2358 ret = __vfs_removexattr_locked(&nop_mnt_idmap, fhp->fh_dentry, 2359 name, NULL); 2360 2361 fh_fill_post_attrs(fhp); 2362 inode_unlock(fhp->fh_dentry->d_inode); 2363 fh_drop_write(fhp); 2364 2365 return nfsd_xattr_errno(ret); 2366 } 2367 2368 __be32 2369 nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name, 2370 void *buf, u32 len, u32 flags) 2371 { 2372 __be32 err; 2373 int ret; 2374 2375 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE); 2376 if (err) 2377 return err; 2378 2379 ret = fh_want_write(fhp); 2380 if (ret) 2381 return nfserrno(ret); 2382 inode_lock(fhp->fh_dentry->d_inode); 2383 fh_fill_pre_attrs(fhp); 2384 2385 ret = __vfs_setxattr_locked(&nop_mnt_idmap, fhp->fh_dentry, name, buf, 2386 len, flags, NULL); 2387 fh_fill_post_attrs(fhp); 2388 inode_unlock(fhp->fh_dentry->d_inode); 2389 fh_drop_write(fhp); 2390 2391 return nfsd_xattr_errno(ret); 2392 } 2393 #endif 2394 2395 /* 2396 * Check for a user's access permissions to this inode. 2397 */ 2398 __be32 2399 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, 2400 struct dentry *dentry, int acc) 2401 { 2402 struct inode *inode = d_inode(dentry); 2403 int err; 2404 2405 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP) 2406 return 0; 2407 #if 0 2408 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", 2409 acc, 2410 (acc & NFSD_MAY_READ)? " read" : "", 2411 (acc & NFSD_MAY_WRITE)? " write" : "", 2412 (acc & NFSD_MAY_EXEC)? " exec" : "", 2413 (acc & NFSD_MAY_SATTR)? " sattr" : "", 2414 (acc & NFSD_MAY_TRUNC)? " trunc" : "", 2415 (acc & NFSD_MAY_LOCK)? " lock" : "", 2416 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", 2417 inode->i_mode, 2418 IS_IMMUTABLE(inode)? " immut" : "", 2419 IS_APPEND(inode)? " append" : "", 2420 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); 2421 dprintk(" owner %d/%d user %d/%d\n", 2422 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); 2423 #endif 2424 2425 /* Normally we reject any write/sattr etc access on a read-only file 2426 * system. But if it is IRIX doing check on write-access for a 2427 * device special file, we ignore rofs. 2428 */ 2429 if (!(acc & NFSD_MAY_LOCAL_ACCESS)) 2430 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { 2431 if (exp_rdonly(rqstp, exp) || 2432 __mnt_is_readonly(exp->ex_path.mnt)) 2433 return nfserr_rofs; 2434 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) 2435 return nfserr_perm; 2436 } 2437 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) 2438 return nfserr_perm; 2439 2440 if (acc & NFSD_MAY_LOCK) { 2441 /* If we cannot rely on authentication in NLM requests, 2442 * just allow locks, otherwise require read permission, or 2443 * ownership 2444 */ 2445 if (exp->ex_flags & NFSEXP_NOAUTHNLM) 2446 return 0; 2447 else 2448 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE; 2449 } 2450 /* 2451 * The file owner always gets access permission for accesses that 2452 * would normally be checked at open time. This is to make 2453 * file access work even when the client has done a fchmod(fd, 0). 2454 * 2455 * However, `cp foo bar' should fail nevertheless when bar is 2456 * readonly. A sensible way to do this might be to reject all 2457 * attempts to truncate a read-only file, because a creat() call 2458 * always implies file truncation. 2459 * ... but this isn't really fair. A process may reasonably call 2460 * ftruncate on an open file descriptor on a file with perm 000. 2461 * We must trust the client to do permission checking - using "ACCESS" 2462 * with NFSv3. 2463 */ 2464 if ((acc & NFSD_MAY_OWNER_OVERRIDE) && 2465 uid_eq(inode->i_uid, current_fsuid())) 2466 return 0; 2467 2468 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ 2469 err = inode_permission(&nop_mnt_idmap, inode, 2470 acc & (MAY_READ | MAY_WRITE | MAY_EXEC)); 2471 2472 /* Allow read access to binaries even when mode 111 */ 2473 if (err == -EACCES && S_ISREG(inode->i_mode) && 2474 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) || 2475 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC))) 2476 err = inode_permission(&nop_mnt_idmap, inode, MAY_EXEC); 2477 2478 return err? nfserrno(err) : 0; 2479 } 2480