1 // SPDX-License-Identifier: GPL-2.0
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.
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.
13 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
14 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
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>
39 #include "../internal.h"
43 #endif /* CONFIG_NFSD_V4 */
47 #include "filecache.h"
50 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
53 * nfserrno - Map Linux errnos to NFS errnos
54 * @errno: POSIX(-ish) error code to be mapped
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.
67 { nfserr_perm, -EPERM },
68 { nfserr_noent, -ENOENT },
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},
107 for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) {
108 if (nfs_errtbl[i].syserr == errno)
109 return nfs_errtbl[i].nfserr;
111 WARN_ONCE(1, "nfsd: non-standard errno: %d\n", errno);
116 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
118 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
119 * or nfs_ok having possibly changed *dpp and *expp
122 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
123 struct svc_export **expp)
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;
132 if (exp->ex_flags & NFSEXP_CROSSMOUNT)
133 follow_flags = LOOKUP_AUTOMOUNT;
135 err = follow_down(&path, follow_flags);
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 */
145 exp2 = rqst_exp_get_by_name(rqstp, &path);
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
155 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
160 if (nfsd_v4client(rqstp) ||
161 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
162 /* successfully crossed mount point */
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
170 path.dentry = dentry;
180 static void follow_to_parent(struct path *path)
184 while (path->dentry == path->mnt->mnt_root && follow_up(path))
186 dp = dget_parent(path->dentry);
191 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
193 struct svc_export *exp2;
194 struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
195 .dentry = dget(dparent)};
197 follow_to_parent(&path);
199 exp2 = rqst_exp_parent(rqstp, &path);
200 if (PTR_ERR(exp2) == -ENOENT) {
201 *dentryp = dget(dparent);
202 } else if (IS_ERR(exp2)) {
204 return PTR_ERR(exp2);
206 *dentryp = dget(path.dentry);
215 * For nfsd purposes, we treat V4ROOT exports as though there was an
216 * export at *every* directory.
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.
222 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
224 if (!d_inode(dentry))
226 if (exp->ex_flags & NFSEXP_V4ROOT)
228 if (nfsd4_is_junction(dentry))
230 if (d_managed(dentry))
232 * Might only be a mountpoint in a different namespace,
233 * but we need to check.
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)
244 struct svc_export *exp;
245 struct dentry *dparent;
246 struct dentry *dentry;
249 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
251 dparent = fhp->fh_dentry;
252 exp = exp_get(fhp->fh_export);
254 /* Lookup the name, but don't follow links */
255 if (isdotent(name, len)) {
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 / */
263 /* checking mountpoint crossing is very different when stepping up */
264 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
269 dentry = lookup_one_len_unlocked(name, dparent, len);
270 host_err = PTR_ERR(dentry);
273 if (nfsd_mountpoint(dentry, exp)) {
274 host_err = nfsd_cross_mnt(rqstp, &dentry, &exp);
281 *dentry_ret = dentry;
287 return nfserrno(host_err);
291 * nfsd_lookup - look up a single path component for nfsd
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.
299 * Look up one component of a pathname.
300 * N.B. After this call _both_ fhp and resfh need an fh_put
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
311 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
312 unsigned int len, struct svc_fh *resfh)
314 struct svc_export *exp;
315 struct dentry *dentry;
318 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
321 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
324 err = check_nfsd_access(exp, rqstp);
328 * Note: we compose the file handle now, but as the
329 * dentry may be negative, it may need to be updated.
331 err = fh_compose(resfh, exp, dentry, fhp);
332 if (!err && d_really_is_negative(dentry))
341 * Commit metadata changes to stable storage.
344 commit_inode_metadata(struct inode *inode)
346 const struct export_operations *export_ops = inode->i_sb->s_export_op;
348 if (export_ops->commit_metadata)
349 return export_ops->commit_metadata(inode);
350 return sync_inode_metadata(inode, 1);
354 commit_metadata(struct svc_fh *fhp)
356 struct inode *inode = d_inode(fhp->fh_dentry);
358 if (!EX_ISSYNC(fhp->fh_export))
360 return commit_inode_metadata(inode);
364 * Go over the attributes and take care of the small differences between
365 * NFS semantics and what Linux expects.
368 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
370 /* Ignore mode updates on symlinks */
371 if (S_ISLNK(inode->i_mode))
372 iap->ia_valid &= ~ATTR_MODE;
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);
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;
390 /* set ATTR_KILL_* bits and let VFS handle it */
391 iap->ia_valid |= ATTR_KILL_SUID;
393 setattr_should_drop_sgid(&nop_mnt_idmap, inode);
399 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
402 struct inode *inode = d_inode(fhp->fh_dentry);
404 if (iap->ia_size < inode->i_size) {
407 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
408 NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
412 return nfserrno(get_write_access(inode));
415 static int __nfsd_setattr(struct dentry *dentry, struct iattr *iap)
419 if (iap->ia_valid & ATTR_SIZE) {
421 * RFC5661, Section 18.30.4:
422 * Changing the size of a file with SETATTR indirectly
423 * changes the time_modify and change attributes.
425 * (and similar for the older RFCs)
427 struct iattr size_attr = {
428 .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
429 .ia_size = iap->ia_size,
432 if (iap->ia_size < 0)
435 host_err = notify_change(&nop_mnt_idmap, dentry, &size_attr, NULL);
438 iap->ia_valid &= ~ATTR_SIZE;
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.
445 if ((iap->ia_valid & ~ATTR_MTIME) == 0)
452 iap->ia_valid |= ATTR_CTIME;
453 return notify_change(&nop_mnt_idmap, dentry, iap, NULL);
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
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).
467 * Returns nfs_ok on success, otherwise an NFS status code is
468 * returned. Caller must release @fhp by calling fh_put in either
472 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
473 struct nfsd_attrs *attr,
474 int check_guard, time64_t guardtime)
476 struct dentry *dentry;
478 struct iattr *iap = attr->na_iattr;
479 int accmode = NFSD_MAY_SATTR;
483 bool get_write_count;
484 bool size_change = (iap->ia_valid & ATTR_SIZE);
487 if (iap->ia_valid & ATTR_SIZE) {
488 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
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).
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;
505 /* Callers that do fh_verify should do the fh_want_write: */
506 get_write_count = !fhp->fh_dentry;
509 err = fh_verify(rqstp, fhp, ftype, accmode);
512 if (get_write_count) {
513 host_err = fh_want_write(fhp);
518 dentry = fhp->fh_dentry;
519 inode = d_inode(dentry);
521 nfsd_sanitize_attrs(inode, iap);
523 if (check_guard && guardtime != inode->i_ctime.tv_sec)
524 return nfserr_notsync;
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
534 err = nfsd_get_write_access(rqstp, fhp, iap);
540 for (retries = 1;;) {
544 * notify_change() can alter its iattr argument, making
545 * @iap unsuitable for submission multiple times. Make a
546 * copy for every loop iteration.
549 host_err = __nfsd_setattr(dentry, &attrs);
550 if (host_err != -EAGAIN || !retries--)
552 if (!nfsd_wait_for_delegreturn(rqstp, inode))
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,
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,
569 put_write_access(inode);
572 host_err = commit_metadata(fhp);
573 return nfserrno(host_err);
576 #if defined(CONFIG_NFSD_V4)
578 * NFS junction information is stored in an extended attribute.
580 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
583 * nfsd4_is_junction - Test if an object could be an NFS junction
585 * @dentry: object to test
587 * Returns 1 if "dentry" appears to contain NFS junction information.
588 * Otherwise 0 is returned.
590 int nfsd4_is_junction(struct dentry *dentry)
592 struct inode *inode = d_inode(dentry);
596 if (inode->i_mode & S_IXUGO)
598 if (!(inode->i_mode & S_ISVTX))
600 if (vfs_getxattr(&nop_mnt_idmap, dentry, NFSD_JUNCTION_XATTR_NAME,
606 static struct nfsd4_compound_state *nfsd4_get_cstate(struct svc_rqst *rqstp)
608 return &((struct nfsd4_compoundres *)rqstp->rq_resp)->cstate;
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)
616 struct file *src = nf_src->nf_file;
617 struct file *dst = nf_dst->nf_file;
622 since = READ_ONCE(dst->f_wb_err);
623 cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
625 ret = nfserrno(cloned);
628 if (count && cloned != count) {
629 ret = nfserrno(-EINVAL);
633 loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
634 int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
637 status = filemap_check_wb_err(dst->f_mapping, since);
639 status = commit_inode_metadata(file_inode(src));
641 struct nfsd_net *nn = net_generic(nf_dst->nf_net,
644 trace_nfsd_clone_file_range_err(rqstp,
645 &nfsd4_get_cstate(rqstp)->save_fh,
647 &nfsd4_get_cstate(rqstp)->current_fh,
650 nfsd_reset_write_verifier(nn);
651 trace_nfsd_writeverf_reset(nn, rqstp, status);
652 ret = nfserrno(status);
659 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
660 u64 dst_pos, u64 count)
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.
672 count = min_t(u64, count, 1 << 22);
673 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
675 if (ret == -EOPNOTSUPP || ret == -EXDEV)
676 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count,
681 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
682 struct file *file, loff_t offset, loff_t len,
687 if (!S_ISREG(file_inode(file)->i_mode))
690 error = vfs_fallocate(file, flags, offset, len);
692 error = commit_metadata(fhp);
694 return nfserrno(error);
696 #endif /* defined(CONFIG_NFSD_V4) */
699 * Check server access rights to a file system object
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 },
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 },
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 },
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 },
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
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 },
753 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
755 struct accessmap *map;
756 struct svc_export *export;
757 struct dentry *dentry;
758 u32 query, result = 0, sresult = 0;
761 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
765 export = fhp->fh_export;
766 dentry = fhp->fh_dentry;
768 if (d_is_reg(dentry))
769 map = nfs3_regaccess;
770 else if (d_is_dir(dentry))
771 map = nfs3_diraccess;
773 map = nfs3_anyaccess;
777 for (; map->access; map++) {
778 if (map->access & query) {
781 sresult |= map->access;
783 err2 = nfsd_permission(rqstp, export, dentry, map->how);
786 result |= map->access;
789 /* the following error codes just mean the access was not allowed,
790 * rather than an error occurred */
794 /* simply don't "or" in the access bit. */
804 *supported = sresult;
810 int nfsd_open_break_lease(struct inode *inode, int access)
814 if (access & NFSD_MAY_NOT_BREAK_LEASE)
816 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
817 return break_lease(inode, mode | O_NONBLOCK);
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
827 __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
828 int may_flags, struct file **filp)
833 int flags = O_RDONLY|O_LARGEFILE;
837 path.mnt = fhp->fh_export->ex_path.mnt;
838 path.dentry = fhp->fh_dentry;
839 inode = d_inode(path.dentry);
842 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
848 host_err = nfsd_open_break_lease(inode, may_flags);
849 if (host_err) /* NOMEM or WOULDBLOCK */
852 if (may_flags & NFSD_MAY_WRITE) {
853 if (may_flags & NFSD_MAY_READ)
854 flags = O_RDWR|O_LARGEFILE;
856 flags = O_WRONLY|O_LARGEFILE;
859 file = dentry_open(&path, flags, current_cred());
861 host_err = PTR_ERR(file);
865 host_err = ima_file_check(file, may_flags);
871 if (may_flags & NFSD_MAY_64BIT_COOKIE)
872 file->f_mode |= FMODE_64BITHASH;
874 file->f_mode |= FMODE_32BITHASH;
878 err = nfserrno(host_err);
884 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
885 int may_flags, struct file **filp)
888 bool retried = false;
890 validate_process_creds();
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.
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.
903 may_flags |= NFSD_MAY_OWNER_OVERRIDE;
905 err = fh_verify(rqstp, fhp, type, may_flags);
907 err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
908 if (err == nfserr_stale && !retried) {
914 validate_process_creds();
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 *"
925 * Returns an nfsstat value in network byte order.
928 nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, int may_flags,
933 validate_process_creds();
934 err = __nfsd_open(rqstp, fhp, S_IFREG, may_flags, filp);
935 validate_process_creds();
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 routines
942 * directly. They will be released after the sending has completed.
944 * Return values: Number of bytes consumed, or -EIO if there are no
945 * remaining pages in rqstp->rq_pages.
948 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
949 struct splice_desc *sd)
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;
956 last_page = page + (offset + sd->len - 1) / PAGE_SIZE;
957 for (page += offset / PAGE_SIZE; page <= last_page; page++) {
959 * Skip page replacement when extending the contents
960 * of the current page.
962 if (page == *(rqstp->rq_next_page - 1))
964 if (unlikely(!svc_rqst_replace_page(rqstp, page)))
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;
973 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
974 struct splice_desc *sd)
976 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
979 static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
982 if (expected != 0 && len == 0)
984 if (offset+len >= i_size_read(file_inode(file)))
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)
994 nfsd_stats_io_read_add(fhp->fh_export, host_err);
995 *eof = nfsd_eof_on_read(file, offset, host_err, *count);
997 fsnotify_access(file);
998 trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
1001 trace_nfsd_read_err(rqstp, fhp, offset, host_err);
1002 return nfserrno(host_err);
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
1015 * Returns nfs_ok on success, otherwise an nfserr stat value is
1018 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1019 struct file *file, loff_t offset, unsigned long *count,
1022 struct splice_desc sd = {
1024 .total_len = *count,
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);
1036 * nfsd_iter_read - Perform a VFS read using an iterator
1037 * @rqstp: RPC transaction context
1038 * @fhp: file handle of file to be read
1039 * @file: opened struct file of file to be read
1040 * @offset: starting byte offset
1041 * @count: IN: requested number of bytes; OUT: number of bytes read
1042 * @base: offset in first page of read buffer
1043 * @eof: OUT: set non-zero if operation reached the end of the file
1045 * Some filesystems or situations cannot use nfsd_splice_read. This
1046 * function is the slightly less-performant fallback for those cases.
1048 * Returns nfs_ok on success, otherwise an nfserr stat value is
1051 __be32 nfsd_iter_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1052 struct file *file, loff_t offset, unsigned long *count,
1053 unsigned int base, u32 *eof)
1055 unsigned long v, total;
1056 struct iov_iter iter;
1057 loff_t ppos = offset;
1064 page = *(rqstp->rq_next_page++);
1065 rqstp->rq_vec[v].iov_base = page_address(page) + base;
1066 rqstp->rq_vec[v].iov_len = min_t(size_t, total, PAGE_SIZE - base);
1067 total -= rqstp->rq_vec[v].iov_len;
1071 WARN_ON_ONCE(v > ARRAY_SIZE(rqstp->rq_vec));
1073 trace_nfsd_read_vector(rqstp, fhp, offset, *count);
1074 iov_iter_kvec(&iter, ITER_DEST, rqstp->rq_vec, v, *count);
1075 host_err = vfs_iter_read(file, &iter, &ppos, 0);
1076 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
1080 * Gathered writes: If another process is currently writing to the file,
1081 * there's a high chance this is another nfsd (triggered by a bulk write
1082 * from a client's biod). Rather than syncing the file with each write
1083 * request, we sleep for 10 msec.
1085 * I don't know if this roughly approximates C. Juszak's idea of
1086 * gathered writes, but it's a nice and simple solution (IMHO), and it
1089 * Note: we do this only in the NFSv2 case, since v3 and higher have a
1090 * better tool (separate unstable writes and commits) for solving this
1093 static int wait_for_concurrent_writes(struct file *file)
1095 struct inode *inode = file_inode(file);
1096 static ino_t last_ino;
1097 static dev_t last_dev;
1100 if (atomic_read(&inode->i_writecount) > 1
1101 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
1102 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
1104 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
1107 if (inode->i_state & I_DIRTY) {
1108 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
1109 err = vfs_fsync(file, 0);
1111 last_ino = inode->i_ino;
1112 last_dev = inode->i_sb->s_dev;
1117 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
1118 loff_t offset, struct kvec *vec, int vlen,
1119 unsigned long *cnt, int stable,
1122 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1123 struct file *file = nf->nf_file;
1124 struct super_block *sb = file_inode(file)->i_sb;
1125 struct svc_export *exp;
1126 struct iov_iter iter;
1131 loff_t pos = offset;
1132 unsigned long exp_op_flags = 0;
1133 unsigned int pflags = current->flags;
1135 bool restore_flags = false;
1137 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
1139 if (sb->s_export_op)
1140 exp_op_flags = sb->s_export_op->flags;
1142 if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&
1143 !(exp_op_flags & EXPORT_OP_REMOTE_FS)) {
1145 * We want throttling in balance_dirty_pages()
1146 * and shrink_inactive_list() to only consider
1147 * the backingdev we are writing to, so that nfs to
1148 * localhost doesn't cause nfsd to lock up due to all
1149 * the client's dirty pages or its congested queue.
1151 current->flags |= PF_LOCAL_THROTTLE;
1152 restore_flags = true;
1155 exp = fhp->fh_export;
1156 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
1158 if (!EX_ISSYNC(exp))
1159 stable = NFS_UNSTABLE;
1161 if (stable && !use_wgather)
1164 iov_iter_kvec(&iter, ITER_SOURCE, vec, vlen, *cnt);
1165 since = READ_ONCE(file->f_wb_err);
1167 nfsd_copy_write_verifier(verf, nn);
1168 file_start_write(file);
1169 host_err = vfs_iter_write(file, &iter, &pos, flags);
1170 file_end_write(file);
1172 nfsd_reset_write_verifier(nn);
1173 trace_nfsd_writeverf_reset(nn, rqstp, host_err);
1177 nfsd_stats_io_write_add(exp, *cnt);
1178 fsnotify_modify(file);
1179 host_err = filemap_check_wb_err(file->f_mapping, since);
1183 if (stable && use_wgather) {
1184 host_err = wait_for_concurrent_writes(file);
1186 nfsd_reset_write_verifier(nn);
1187 trace_nfsd_writeverf_reset(nn, rqstp, host_err);
1192 if (host_err >= 0) {
1193 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
1196 trace_nfsd_write_err(rqstp, fhp, offset, host_err);
1197 nfserr = nfserrno(host_err);
1200 current_restore_flags(pflags, PF_LOCAL_THROTTLE);
1205 * nfsd_read - Read data from a file
1206 * @rqstp: RPC transaction context
1207 * @fhp: file handle of file to be read
1208 * @offset: starting byte offset
1209 * @count: IN: requested number of bytes; OUT: number of bytes read
1210 * @eof: OUT: set non-zero if operation reached the end of the file
1212 * The caller must verify that there is enough space in @rqstp.rq_res
1213 * to perform this operation.
1215 * N.B. After this call fhp needs an fh_put
1217 * Returns nfs_ok on success, otherwise an nfserr stat value is
1220 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1221 loff_t offset, unsigned long *count, u32 *eof)
1223 struct nfsd_file *nf;
1227 trace_nfsd_read_start(rqstp, fhp, offset, *count);
1228 err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_READ, &nf);
1233 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
1234 err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
1236 err = nfsd_iter_read(rqstp, fhp, file, offset, count, 0, eof);
1239 trace_nfsd_read_done(rqstp, fhp, offset, *count);
1244 * Write data to a file.
1245 * The stable flag requests synchronous writes.
1246 * N.B. After this call fhp needs an fh_put
1249 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
1250 struct kvec *vec, int vlen, unsigned long *cnt, int stable,
1253 struct nfsd_file *nf;
1256 trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
1258 err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_WRITE, &nf);
1262 err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,
1263 vlen, cnt, stable, verf);
1266 trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
1271 * nfsd_commit - Commit pending writes to stable storage
1272 * @rqstp: RPC request being processed
1273 * @fhp: NFS filehandle
1275 * @offset: raw offset from beginning of file
1276 * @count: raw count of bytes to sync
1277 * @verf: filled in with the server's current write verifier
1279 * Note: we guarantee that data that lies within the range specified
1280 * by the 'offset' and 'count' parameters will be synced. The server
1281 * is permitted to sync data that lies outside this range at the
1284 * Unfortunately we cannot lock the file to make sure we return full WCC
1285 * data to the client, as locking happens lower down in the filesystem.
1288 * An nfsstat value in network byte order.
1291 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
1292 u64 offset, u32 count, __be32 *verf)
1294 __be32 err = nfs_ok;
1297 struct nfsd_net *nn;
1300 * Convert the client-provided (offset, count) range to a
1301 * (start, end) range. If the client-provided range falls
1302 * outside the maximum file size of the underlying FS,
1303 * clamp the sync range appropriately.
1307 maxbytes = (u64)fhp->fh_dentry->d_sb->s_maxbytes;
1308 if (offset < maxbytes) {
1310 if (count && (offset + count - 1 < maxbytes))
1311 end = offset + count - 1;
1314 nn = net_generic(nf->nf_net, nfsd_net_id);
1315 if (EX_ISSYNC(fhp->fh_export)) {
1316 errseq_t since = READ_ONCE(nf->nf_file->f_wb_err);
1319 err2 = vfs_fsync_range(nf->nf_file, start, end, 0);
1322 nfsd_copy_write_verifier(verf, nn);
1323 err2 = filemap_check_wb_err(nf->nf_file->f_mapping,
1325 err = nfserrno(err2);
1328 err = nfserr_notsupp;
1331 nfsd_reset_write_verifier(nn);
1332 trace_nfsd_writeverf_reset(nn, rqstp, err2);
1333 err = nfserrno(err2);
1336 nfsd_copy_write_verifier(verf, nn);
1342 * nfsd_create_setattr - Set a created file's attributes
1343 * @rqstp: RPC transaction being executed
1344 * @fhp: NFS filehandle of parent directory
1345 * @resfhp: NFS filehandle of new object
1346 * @attrs: requested attributes of new object
1348 * Returns nfs_ok on success, or an nfsstat in network byte order.
1351 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
1352 struct svc_fh *resfhp, struct nfsd_attrs *attrs)
1354 struct iattr *iap = attrs->na_iattr;
1358 * Mode has already been set by file creation.
1360 iap->ia_valid &= ~ATTR_MODE;
1363 * Setting uid/gid works only for root. Irix appears to
1364 * send along the gid on create when it tries to implement
1365 * setgid directories via NFS:
1367 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1368 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1371 * Callers expect new file metadata to be committed even
1372 * if the attributes have not changed.
1375 status = nfsd_setattr(rqstp, resfhp, attrs, 0, (time64_t)0);
1377 status = nfserrno(commit_metadata(resfhp));
1380 * Transactional filesystems had a chance to commit changes
1381 * for both parent and child simultaneously making the
1382 * following commit_metadata a noop in many cases.
1385 status = nfserrno(commit_metadata(fhp));
1388 * Update the new filehandle to pick up the new attributes.
1391 status = fh_update(resfhp);
1396 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1397 * setting size to 0 may fail for some specific file systems by the permission
1398 * checking which requires WRITE permission but the mode is 000.
1399 * we ignore the resizing(to 0) on the just new created file, since the size is
1400 * 0 after file created.
1402 * call this only after vfs_create() is called.
1405 nfsd_check_ignore_resizing(struct iattr *iap)
1407 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1408 iap->ia_valid &= ~ATTR_SIZE;
1411 /* The parent directory should already be locked: */
1413 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
1414 struct nfsd_attrs *attrs,
1415 int type, dev_t rdev, struct svc_fh *resfhp)
1417 struct dentry *dentry, *dchild;
1419 struct iattr *iap = attrs->na_iattr;
1423 dentry = fhp->fh_dentry;
1424 dirp = d_inode(dentry);
1426 dchild = dget(resfhp->fh_dentry);
1427 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
1431 if (!(iap->ia_valid & ATTR_MODE))
1433 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1435 if (!IS_POSIXACL(dirp))
1436 iap->ia_mode &= ~current_umask();
1441 host_err = vfs_create(&nop_mnt_idmap, dirp, dchild,
1442 iap->ia_mode, true);
1444 nfsd_check_ignore_resizing(iap);
1447 host_err = vfs_mkdir(&nop_mnt_idmap, dirp, dchild, iap->ia_mode);
1448 if (!host_err && unlikely(d_unhashed(dchild))) {
1450 d = lookup_one_len(dchild->d_name.name,
1452 dchild->d_name.len);
1454 host_err = PTR_ERR(d);
1457 if (unlikely(d_is_negative(d))) {
1459 err = nfserr_serverfault;
1462 dput(resfhp->fh_dentry);
1463 resfhp->fh_dentry = dget(d);
1464 err = fh_update(resfhp);
1475 host_err = vfs_mknod(&nop_mnt_idmap, dirp, dchild,
1476 iap->ia_mode, rdev);
1479 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1486 err = nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
1493 err = nfserrno(host_err);
1498 * Create a filesystem object (regular, directory, special).
1499 * Note that the parent directory is left locked.
1501 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1504 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1505 char *fname, int flen, struct nfsd_attrs *attrs,
1506 int type, dev_t rdev, struct svc_fh *resfhp)
1508 struct dentry *dentry, *dchild = NULL;
1512 if (isdotent(fname, flen))
1513 return nfserr_exist;
1515 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
1519 dentry = fhp->fh_dentry;
1521 host_err = fh_want_write(fhp);
1523 return nfserrno(host_err);
1525 inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
1526 dchild = lookup_one_len(fname, dentry, flen);
1527 host_err = PTR_ERR(dchild);
1528 if (IS_ERR(dchild)) {
1529 err = nfserrno(host_err);
1532 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1534 * We unconditionally drop our ref to dchild as fh_compose will have
1535 * already grabbed its own ref for it.
1540 fh_fill_pre_attrs(fhp);
1541 err = nfsd_create_locked(rqstp, fhp, attrs, type, rdev, resfhp);
1542 fh_fill_post_attrs(fhp);
1544 inode_unlock(dentry->d_inode);
1549 * Read a symlink. On entry, *lenp must contain the maximum path length that
1550 * fits into the buffer. On return, it contains the true length.
1551 * N.B. After this call fhp needs an fh_put
1554 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1559 DEFINE_DELAYED_CALL(done);
1562 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1566 path.mnt = fhp->fh_export->ex_path.mnt;
1567 path.dentry = fhp->fh_dentry;
1569 if (unlikely(!d_is_symlink(path.dentry)))
1570 return nfserr_inval;
1574 link = vfs_get_link(path.dentry, &done);
1576 return nfserrno(PTR_ERR(link));
1581 memcpy(buf, link, *lenp);
1582 do_delayed_call(&done);
1587 * nfsd_symlink - Create a symlink and look up its inode
1588 * @rqstp: RPC transaction being executed
1589 * @fhp: NFS filehandle of parent directory
1590 * @fname: filename of the new symlink
1591 * @flen: length of @fname
1592 * @path: content of the new symlink (NUL-terminated)
1593 * @attrs: requested attributes of new object
1594 * @resfhp: NFS filehandle of new object
1596 * N.B. After this call _both_ fhp and resfhp need an fh_put
1598 * Returns nfs_ok on success, or an nfsstat in network byte order.
1601 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1602 char *fname, int flen,
1603 char *path, struct nfsd_attrs *attrs,
1604 struct svc_fh *resfhp)
1606 struct dentry *dentry, *dnew;
1611 if (!flen || path[0] == '\0')
1614 if (isdotent(fname, flen))
1617 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1621 host_err = fh_want_write(fhp);
1623 err = nfserrno(host_err);
1627 dentry = fhp->fh_dentry;
1628 inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
1629 dnew = lookup_one_len(fname, dentry, flen);
1631 err = nfserrno(PTR_ERR(dnew));
1632 inode_unlock(dentry->d_inode);
1633 goto out_drop_write;
1635 fh_fill_pre_attrs(fhp);
1636 host_err = vfs_symlink(&nop_mnt_idmap, d_inode(dentry), dnew, path);
1637 err = nfserrno(host_err);
1638 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1640 nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
1641 fh_fill_post_attrs(fhp);
1642 inode_unlock(dentry->d_inode);
1644 err = nfserrno(commit_metadata(fhp));
1646 if (err==0) err = cerr;
1655 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1658 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1659 char *name, int len, struct svc_fh *tfhp)
1661 struct dentry *ddir, *dnew, *dold;
1666 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1669 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1673 if (d_is_dir(tfhp->fh_dentry))
1679 if (isdotent(name, len))
1682 host_err = fh_want_write(tfhp);
1684 err = nfserrno(host_err);
1688 ddir = ffhp->fh_dentry;
1689 dirp = d_inode(ddir);
1690 inode_lock_nested(dirp, I_MUTEX_PARENT);
1692 dnew = lookup_one_len(name, ddir, len);
1694 err = nfserrno(PTR_ERR(dnew));
1698 dold = tfhp->fh_dentry;
1701 if (d_really_is_negative(dold))
1703 fh_fill_pre_attrs(ffhp);
1704 host_err = vfs_link(dold, &nop_mnt_idmap, dirp, dnew, NULL);
1705 fh_fill_post_attrs(ffhp);
1708 err = nfserrno(commit_metadata(ffhp));
1710 err = nfserrno(commit_metadata(tfhp));
1712 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1715 err = nfserrno(host_err);
1719 fh_drop_write(tfhp);
1727 goto out_drop_write;
1731 nfsd_close_cached_files(struct dentry *dentry)
1733 struct inode *inode = d_inode(dentry);
1735 if (inode && S_ISREG(inode->i_mode))
1736 nfsd_file_close_inode_sync(inode);
1740 nfsd_has_cached_files(struct dentry *dentry)
1743 struct inode *inode = d_inode(dentry);
1745 if (inode && S_ISREG(inode->i_mode))
1746 ret = nfsd_file_is_cached(inode);
1752 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1755 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1756 struct svc_fh *tfhp, char *tname, int tlen)
1758 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1759 struct inode *fdir, *tdir;
1762 bool close_cached = false;
1764 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1767 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1771 fdentry = ffhp->fh_dentry;
1772 fdir = d_inode(fdentry);
1774 tdentry = tfhp->fh_dentry;
1775 tdir = d_inode(tdentry);
1778 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1782 host_err = fh_want_write(ffhp);
1784 err = nfserrno(host_err);
1788 trap = lock_rename(tdentry, fdentry);
1789 fh_fill_pre_attrs(ffhp);
1790 fh_fill_pre_attrs(tfhp);
1792 odentry = lookup_one_len(fname, fdentry, flen);
1793 host_err = PTR_ERR(odentry);
1794 if (IS_ERR(odentry))
1798 if (d_really_is_negative(odentry))
1801 if (odentry == trap)
1804 ndentry = lookup_one_len(tname, tdentry, tlen);
1805 host_err = PTR_ERR(ndentry);
1806 if (IS_ERR(ndentry))
1808 host_err = -ENOTEMPTY;
1809 if (ndentry == trap)
1813 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1815 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
1818 if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) &&
1819 nfsd_has_cached_files(ndentry)) {
1820 close_cached = true;
1823 struct renamedata rd = {
1824 .old_mnt_idmap = &nop_mnt_idmap,
1826 .old_dentry = odentry,
1827 .new_mnt_idmap = &nop_mnt_idmap,
1829 .new_dentry = ndentry,
1833 for (retries = 1;;) {
1834 host_err = vfs_rename(&rd);
1835 if (host_err != -EAGAIN || !retries--)
1837 if (!nfsd_wait_for_delegreturn(rqstp, d_inode(odentry)))
1841 host_err = commit_metadata(tfhp);
1843 host_err = commit_metadata(ffhp);
1851 err = nfserrno(host_err);
1853 if (!close_cached) {
1854 fh_fill_post_attrs(ffhp);
1855 fh_fill_post_attrs(tfhp);
1857 unlock_rename(tdentry, fdentry);
1858 fh_drop_write(ffhp);
1861 * If the target dentry has cached open files, then we need to try to
1862 * close them prior to doing the rename. Flushing delayed fput
1863 * shouldn't be done with locks held however, so we delay it until this
1864 * point and then reattempt the whole shebang.
1867 close_cached = false;
1868 nfsd_close_cached_files(ndentry);
1877 * Unlink a file or directory
1878 * N.B. After this call fhp needs an fh_put
1881 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1882 char *fname, int flen)
1884 struct dentry *dentry, *rdentry;
1886 struct inode *rinode;
1891 if (!flen || isdotent(fname, flen))
1893 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1897 host_err = fh_want_write(fhp);
1901 dentry = fhp->fh_dentry;
1902 dirp = d_inode(dentry);
1903 inode_lock_nested(dirp, I_MUTEX_PARENT);
1905 rdentry = lookup_one_len(fname, dentry, flen);
1906 host_err = PTR_ERR(rdentry);
1907 if (IS_ERR(rdentry))
1910 if (d_really_is_negative(rdentry)) {
1915 rinode = d_inode(rdentry);
1919 type = d_inode(rdentry)->i_mode & S_IFMT;
1921 fh_fill_pre_attrs(fhp);
1922 if (type != S_IFDIR) {
1925 if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK)
1926 nfsd_close_cached_files(rdentry);
1928 for (retries = 1;;) {
1929 host_err = vfs_unlink(&nop_mnt_idmap, dirp, rdentry, NULL);
1930 if (host_err != -EAGAIN || !retries--)
1932 if (!nfsd_wait_for_delegreturn(rqstp, rinode))
1936 host_err = vfs_rmdir(&nop_mnt_idmap, dirp, rdentry);
1938 fh_fill_post_attrs(fhp);
1942 host_err = commit_metadata(fhp);
1944 iput(rinode); /* truncate the inode here */
1949 if (host_err == -EBUSY) {
1950 /* name is mounted-on. There is no perfect
1953 if (nfsd_v4client(rqstp))
1954 err = nfserr_file_open;
1958 err = nfserrno(host_err);
1964 goto out_drop_write;
1968 * We do this buffering because we must not call back into the file
1969 * system's ->lookup() method from the filldir callback. That may well
1970 * deadlock a number of file systems.
1972 * This is based heavily on the implementation of same in XFS.
1974 struct buffered_dirent {
1978 unsigned int d_type;
1982 struct readdir_data {
1983 struct dir_context ctx;
1989 static bool nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
1990 int namlen, loff_t offset, u64 ino,
1991 unsigned int d_type)
1993 struct readdir_data *buf =
1994 container_of(ctx, struct readdir_data, ctx);
1995 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1996 unsigned int reclen;
1998 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1999 if (buf->used + reclen > PAGE_SIZE) {
2004 de->namlen = namlen;
2005 de->offset = offset;
2007 de->d_type = d_type;
2008 memcpy(de->name, name, namlen);
2009 buf->used += reclen;
2014 static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,
2015 nfsd_filldir_t func, struct readdir_cd *cdp,
2018 struct buffered_dirent *de;
2022 struct readdir_data buf = {
2023 .ctx.actor = nfsd_buffered_filldir,
2024 .dirent = (void *)__get_free_page(GFP_KERNEL)
2028 return nfserrno(-ENOMEM);
2033 unsigned int reclen;
2035 cdp->err = nfserr_eof; /* will be cleared on successful read */
2039 host_err = iterate_dir(file, &buf.ctx);
2051 de = (struct buffered_dirent *)buf.dirent;
2053 offset = de->offset;
2055 if (func(cdp, de->name, de->namlen, de->offset,
2056 de->ino, de->d_type))
2059 if (cdp->err != nfs_ok)
2062 trace_nfsd_dirent(fhp, de->ino, de->name, de->namlen);
2064 reclen = ALIGN(sizeof(*de) + de->namlen,
2067 de = (struct buffered_dirent *)((char *)de + reclen);
2069 if (size > 0) /* We bailed out early */
2072 offset = vfs_llseek(file, 0, SEEK_CUR);
2075 free_page((unsigned long)(buf.dirent));
2078 return nfserrno(host_err);
2085 * Read entries from a directory.
2086 * The NFSv3/4 verifier we ignore for now.
2089 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
2090 struct readdir_cd *cdp, nfsd_filldir_t func)
2094 loff_t offset = *offsetp;
2095 int may_flags = NFSD_MAY_READ;
2097 /* NFSv2 only supports 32 bit cookies */
2098 if (rqstp->rq_vers > 2)
2099 may_flags |= NFSD_MAY_64BIT_COOKIE;
2101 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
2105 offset = vfs_llseek(file, offset, SEEK_SET);
2107 err = nfserrno((int)offset);
2111 err = nfsd_buffered_readdir(file, fhp, func, cdp, offsetp);
2113 if (err == nfserr_eof || err == nfserr_toosmall)
2114 err = nfs_ok; /* can still be found in ->err */
2122 * Get file system stats
2123 * N.B. After this call fhp needs an fh_put
2126 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
2130 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
2132 struct path path = {
2133 .mnt = fhp->fh_export->ex_path.mnt,
2134 .dentry = fhp->fh_dentry,
2136 if (vfs_statfs(&path, stat))
2142 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
2144 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
2147 #ifdef CONFIG_NFSD_V4
2149 * Helper function to translate error numbers. In the case of xattr operations,
2150 * some error codes need to be translated outside of the standard translations.
2152 * ENODATA needs to be translated to nfserr_noxattr.
2153 * E2BIG to nfserr_xattr2big.
2155 * Additionally, vfs_listxattr can return -ERANGE. This means that the
2156 * file has too many extended attributes to retrieve inside an
2157 * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
2158 * filesystems will allow the adding of extended attributes until they hit
2159 * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
2160 * So, at that point, the attributes are present and valid, but can't
2161 * be retrieved using listxattr, since the upper level xattr code enforces
2162 * the XATTR_LIST_MAX limit.
2164 * This bug means that we need to deal with listxattr returning -ERANGE. The
2165 * best mapping is to return TOOSMALL.
2168 nfsd_xattr_errno(int err)
2172 return nfserr_noxattr;
2174 return nfserr_xattr2big;
2176 return nfserr_toosmall;
2178 return nfserrno(err);
2182 * Retrieve the specified user extended attribute. To avoid always
2183 * having to allocate the maximum size (since we are not getting
2184 * a maximum size from the RPC), do a probe + alloc. Hold a reader
2185 * lock on i_rwsem to prevent the extended attribute from changing
2186 * size while we're doing this.
2189 nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2190 void **bufp, int *lenp)
2195 struct inode *inode;
2196 struct dentry *dentry;
2198 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2203 dentry = fhp->fh_dentry;
2204 inode = d_inode(dentry);
2206 inode_lock_shared(inode);
2208 len = vfs_getxattr(&nop_mnt_idmap, dentry, name, NULL, 0);
2211 * Zero-length attribute, just return.
2220 err = nfsd_xattr_errno(len);
2225 err = nfserr_toosmall;
2229 buf = kvmalloc(len, GFP_KERNEL);
2231 err = nfserr_jukebox;
2235 len = vfs_getxattr(&nop_mnt_idmap, dentry, name, buf, len);
2239 err = nfsd_xattr_errno(len);
2246 inode_unlock_shared(inode);
2252 * Retrieve the xattr names. Since we can't know how many are
2253 * user extended attributes, we must get all attributes here,
2254 * and have the XDR encode filter out the "user." ones.
2256 * While this could always just allocate an XATTR_LIST_MAX
2257 * buffer, that's a waste, so do a probe + allocate. To
2258 * avoid any changes between the probe and allocate, wrap
2259 * this in inode_lock.
2262 nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
2268 struct inode *inode;
2269 struct dentry *dentry;
2271 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2275 dentry = fhp->fh_dentry;
2276 inode = d_inode(dentry);
2279 inode_lock_shared(inode);
2281 len = vfs_listxattr(dentry, NULL, 0);
2283 err = nfsd_xattr_errno(len);
2287 if (len > XATTR_LIST_MAX) {
2288 err = nfserr_xattr2big;
2292 buf = kvmalloc(len, GFP_KERNEL);
2294 err = nfserr_jukebox;
2298 len = vfs_listxattr(dentry, buf, len);
2301 err = nfsd_xattr_errno(len);
2310 inode_unlock_shared(inode);
2316 * nfsd_removexattr - Remove an extended attribute
2317 * @rqstp: RPC transaction being executed
2318 * @fhp: NFS filehandle of object with xattr to remove
2319 * @name: name of xattr to remove (NUL-terminate)
2321 * Pass in a NULL pointer for delegated_inode, and let the client deal
2322 * with NFS4ERR_DELAY (same as with e.g. setattr and remove).
2324 * Returns nfs_ok on success, or an nfsstat in network byte order.
2327 nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
2332 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2336 ret = fh_want_write(fhp);
2338 return nfserrno(ret);
2340 inode_lock(fhp->fh_dentry->d_inode);
2341 fh_fill_pre_attrs(fhp);
2343 ret = __vfs_removexattr_locked(&nop_mnt_idmap, fhp->fh_dentry,
2346 fh_fill_post_attrs(fhp);
2347 inode_unlock(fhp->fh_dentry->d_inode);
2350 return nfsd_xattr_errno(ret);
2354 nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2355 void *buf, u32 len, u32 flags)
2360 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2364 ret = fh_want_write(fhp);
2366 return nfserrno(ret);
2367 inode_lock(fhp->fh_dentry->d_inode);
2368 fh_fill_pre_attrs(fhp);
2370 ret = __vfs_setxattr_locked(&nop_mnt_idmap, fhp->fh_dentry, name, buf,
2372 fh_fill_post_attrs(fhp);
2373 inode_unlock(fhp->fh_dentry->d_inode);
2376 return nfsd_xattr_errno(ret);
2381 * Check for a user's access permissions to this inode.
2384 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2385 struct dentry *dentry, int acc)
2387 struct inode *inode = d_inode(dentry);
2390 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
2393 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2395 (acc & NFSD_MAY_READ)? " read" : "",
2396 (acc & NFSD_MAY_WRITE)? " write" : "",
2397 (acc & NFSD_MAY_EXEC)? " exec" : "",
2398 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2399 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2400 (acc & NFSD_MAY_LOCK)? " lock" : "",
2401 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2403 IS_IMMUTABLE(inode)? " immut" : "",
2404 IS_APPEND(inode)? " append" : "",
2405 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2406 dprintk(" owner %d/%d user %d/%d\n",
2407 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2410 /* Normally we reject any write/sattr etc access on a read-only file
2411 * system. But if it is IRIX doing check on write-access for a
2412 * device special file, we ignore rofs.
2414 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2415 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2416 if (exp_rdonly(rqstp, exp) ||
2417 __mnt_is_readonly(exp->ex_path.mnt))
2419 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2422 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2425 if (acc & NFSD_MAY_LOCK) {
2426 /* If we cannot rely on authentication in NLM requests,
2427 * just allow locks, otherwise require read permission, or
2430 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2433 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2436 * The file owner always gets access permission for accesses that
2437 * would normally be checked at open time. This is to make
2438 * file access work even when the client has done a fchmod(fd, 0).
2440 * However, `cp foo bar' should fail nevertheless when bar is
2441 * readonly. A sensible way to do this might be to reject all
2442 * attempts to truncate a read-only file, because a creat() call
2443 * always implies file truncation.
2444 * ... but this isn't really fair. A process may reasonably call
2445 * ftruncate on an open file descriptor on a file with perm 000.
2446 * We must trust the client to do permission checking - using "ACCESS"
2449 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2450 uid_eq(inode->i_uid, current_fsuid()))
2453 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2454 err = inode_permission(&nop_mnt_idmap, inode,
2455 acc & (MAY_READ | MAY_WRITE | MAY_EXEC));
2457 /* Allow read access to binaries even when mode 111 */
2458 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2459 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2460 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2461 err = inode_permission(&nop_mnt_idmap, inode, MAY_EXEC);
2463 return err? nfserrno(err) : 0;