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/slab.h>
30 #include <linux/uaccess.h>
31 #include <linux/exportfs.h>
32 #include <linux/writeback.h>
33 #include <linux/security.h>
37 #endif /* CONFIG_NFSD_V3 */
40 #include "../internal.h"
43 #endif /* CONFIG_NFSD_V4 */
47 #include "filecache.h"
50 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
53 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
55 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
56 * or nfs_ok having possibly changed *dpp and *expp
59 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
60 struct svc_export **expp)
62 struct svc_export *exp = *expp, *exp2 = NULL;
63 struct dentry *dentry = *dpp;
64 struct path path = {.mnt = mntget(exp->ex_path.mnt),
65 .dentry = dget(dentry)};
68 err = follow_down(&path);
71 if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
72 nfsd_mountpoint(dentry, exp) == 2) {
73 /* This is only a mountpoint in some other namespace */
78 exp2 = rqst_exp_get_by_name(rqstp, &path);
82 * We normally allow NFS clients to continue
83 * "underneath" a mountpoint that is not exported.
84 * The exception is V4ROOT, where no traversal is ever
85 * allowed without an explicit export of the new
88 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
93 if (nfsd_v4client(rqstp) ||
94 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
95 /* successfully crossed mount point */
97 * This is subtle: path.dentry is *not* on path.mnt
98 * at this point. The only reason we are safe is that
99 * original mnt is pinned down by exp, so we should
100 * put path *before* putting exp
103 path.dentry = dentry;
113 static void follow_to_parent(struct path *path)
117 while (path->dentry == path->mnt->mnt_root && follow_up(path))
119 dp = dget_parent(path->dentry);
124 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
126 struct svc_export *exp2;
127 struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
128 .dentry = dget(dparent)};
130 follow_to_parent(&path);
132 exp2 = rqst_exp_parent(rqstp, &path);
133 if (PTR_ERR(exp2) == -ENOENT) {
134 *dentryp = dget(dparent);
135 } else if (IS_ERR(exp2)) {
137 return PTR_ERR(exp2);
139 *dentryp = dget(path.dentry);
148 * For nfsd purposes, we treat V4ROOT exports as though there was an
149 * export at *every* directory.
151 * '1' if this dentry *must* be an export point,
152 * '2' if it might be, if there is really a mount here, and
153 * '0' if there is no chance of an export point here.
155 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
157 if (!d_inode(dentry))
159 if (exp->ex_flags & NFSEXP_V4ROOT)
161 if (nfsd4_is_junction(dentry))
163 if (d_mountpoint(dentry))
165 * Might only be a mountpoint in a different namespace,
166 * but we need to check.
173 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
174 const char *name, unsigned int len,
175 struct svc_export **exp_ret, struct dentry **dentry_ret)
177 struct svc_export *exp;
178 struct dentry *dparent;
179 struct dentry *dentry;
182 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
184 dparent = fhp->fh_dentry;
185 exp = exp_get(fhp->fh_export);
187 /* Lookup the name, but don't follow links */
188 if (isdotent(name, len)) {
190 dentry = dget(dparent);
191 else if (dparent != exp->ex_path.dentry)
192 dentry = dget_parent(dparent);
193 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
194 dentry = dget(dparent); /* .. == . just like at / */
196 /* checking mountpoint crossing is very different when stepping up */
197 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
203 * In the nfsd4_open() case, this may be held across
204 * subsequent open and delegation acquisition which may
205 * need to take the child's i_mutex:
207 fh_lock_nested(fhp, I_MUTEX_PARENT);
208 dentry = lookup_one_len(name, dparent, len);
209 host_err = PTR_ERR(dentry);
212 if (nfsd_mountpoint(dentry, exp)) {
214 * We don't need the i_mutex after all. It's
215 * still possible we could open this (regular
216 * files can be mountpoints too), but the
217 * i_mutex is just there to prevent renames of
218 * something that we might be about to delegate,
219 * and a mountpoint won't be renamed:
222 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
228 *dentry_ret = dentry;
234 return nfserrno(host_err);
238 * Look up one component of a pathname.
239 * N.B. After this call _both_ fhp and resfh need an fh_put
241 * If the lookup would cross a mountpoint, and the mounted filesystem
242 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
243 * accepted as it stands and the mounted directory is
244 * returned. Otherwise the covered directory is returned.
245 * NOTE: this mountpoint crossing is not supported properly by all
246 * clients and is explicitly disallowed for NFSv3
247 * NeilBrown <neilb@cse.unsw.edu.au>
250 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
251 unsigned int len, struct svc_fh *resfh)
253 struct svc_export *exp;
254 struct dentry *dentry;
257 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
260 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
263 err = check_nfsd_access(exp, rqstp);
267 * Note: we compose the file handle now, but as the
268 * dentry may be negative, it may need to be updated.
270 err = fh_compose(resfh, exp, dentry, fhp);
271 if (!err && d_really_is_negative(dentry))
280 * Commit metadata changes to stable storage.
283 commit_inode_metadata(struct inode *inode)
285 const struct export_operations *export_ops = inode->i_sb->s_export_op;
287 if (export_ops->commit_metadata)
288 return export_ops->commit_metadata(inode);
289 return sync_inode_metadata(inode, 1);
293 commit_metadata(struct svc_fh *fhp)
295 struct inode *inode = d_inode(fhp->fh_dentry);
297 if (!EX_ISSYNC(fhp->fh_export))
299 return commit_inode_metadata(inode);
303 * Go over the attributes and take care of the small differences between
304 * NFS semantics and what Linux expects.
307 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
309 /* sanitize the mode change */
310 if (iap->ia_valid & ATTR_MODE) {
311 iap->ia_mode &= S_IALLUGO;
312 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
315 /* Revoke setuid/setgid on chown */
316 if (!S_ISDIR(inode->i_mode) &&
317 ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
318 iap->ia_valid |= ATTR_KILL_PRIV;
319 if (iap->ia_valid & ATTR_MODE) {
320 /* we're setting mode too, just clear the s*id bits */
321 iap->ia_mode &= ~S_ISUID;
322 if (iap->ia_mode & S_IXGRP)
323 iap->ia_mode &= ~S_ISGID;
325 /* set ATTR_KILL_* bits and let VFS handle it */
326 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
332 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
335 struct inode *inode = d_inode(fhp->fh_dentry);
338 if (iap->ia_size < inode->i_size) {
341 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
342 NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
347 host_err = get_write_access(inode);
351 host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
353 goto out_put_write_access;
356 out_put_write_access:
357 put_write_access(inode);
359 return nfserrno(host_err);
363 * Set various file attributes. After this call fhp needs an fh_put.
366 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
367 int check_guard, time64_t guardtime)
369 struct dentry *dentry;
371 int accmode = NFSD_MAY_SATTR;
375 bool get_write_count;
376 bool size_change = (iap->ia_valid & ATTR_SIZE);
378 if (iap->ia_valid & ATTR_SIZE) {
379 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
384 * If utimes(2) and friends are called with times not NULL, we should
385 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
386 * will return EACCES, when the caller's effective UID does not match
387 * the owner of the file, and the caller is not privileged. In this
388 * situation, we should return EPERM(notify_change will return this).
390 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) {
391 accmode |= NFSD_MAY_OWNER_OVERRIDE;
392 if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET)))
393 accmode |= NFSD_MAY_WRITE;
396 /* Callers that do fh_verify should do the fh_want_write: */
397 get_write_count = !fhp->fh_dentry;
400 err = fh_verify(rqstp, fhp, ftype, accmode);
403 if (get_write_count) {
404 host_err = fh_want_write(fhp);
409 dentry = fhp->fh_dentry;
410 inode = d_inode(dentry);
412 /* Ignore any mode updates on symlinks */
413 if (S_ISLNK(inode->i_mode))
414 iap->ia_valid &= ~ATTR_MODE;
419 nfsd_sanitize_attrs(inode, iap);
421 if (check_guard && guardtime != inode->i_ctime.tv_sec)
422 return nfserr_notsync;
425 * The size case is special, it changes the file in addition to the
426 * attributes, and file systems don't expect it to be mixed with
427 * "random" attribute changes. We thus split out the size change
428 * into a separate call to ->setattr, and do the rest as a separate
432 err = nfsd_get_write_access(rqstp, fhp, iap);
440 * RFC5661, Section 18.30.4:
441 * Changing the size of a file with SETATTR indirectly
442 * changes the time_modify and change attributes.
444 * (and similar for the older RFCs)
446 struct iattr size_attr = {
447 .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
448 .ia_size = iap->ia_size,
451 host_err = notify_change(&init_user_ns, dentry, &size_attr, NULL);
454 iap->ia_valid &= ~ATTR_SIZE;
457 * Avoid the additional setattr call below if the only other
458 * attribute that the client sends is the mtime, as we update
459 * it as part of the size change above.
461 if ((iap->ia_valid & ~ATTR_MTIME) == 0)
465 iap->ia_valid |= ATTR_CTIME;
466 host_err = notify_change(&init_user_ns, dentry, iap, NULL);
471 put_write_access(inode);
474 host_err = commit_metadata(fhp);
475 return nfserrno(host_err);
478 #if defined(CONFIG_NFSD_V4)
480 * NFS junction information is stored in an extended attribute.
482 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
485 * nfsd4_is_junction - Test if an object could be an NFS junction
487 * @dentry: object to test
489 * Returns 1 if "dentry" appears to contain NFS junction information.
490 * Otherwise 0 is returned.
492 int nfsd4_is_junction(struct dentry *dentry)
494 struct inode *inode = d_inode(dentry);
498 if (inode->i_mode & S_IXUGO)
500 if (!(inode->i_mode & S_ISVTX))
502 if (vfs_getxattr(&init_user_ns, dentry, NFSD_JUNCTION_XATTR_NAME,
507 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
508 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
509 struct xdr_netobj *label)
513 struct dentry *dentry;
515 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
519 dentry = fhp->fh_dentry;
521 inode_lock(d_inode(dentry));
522 host_error = security_inode_setsecctx(dentry, label->data, label->len);
523 inode_unlock(d_inode(dentry));
524 return nfserrno(host_error);
527 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
528 struct xdr_netobj *label)
530 return nfserr_notsupp;
534 __be32 nfsd4_clone_file_range(struct nfsd_file *nf_src, u64 src_pos,
535 struct nfsd_file *nf_dst, u64 dst_pos, u64 count, bool sync)
537 struct file *src = nf_src->nf_file;
538 struct file *dst = nf_dst->nf_file;
542 down_write(&nf_dst->nf_rwsem);
543 cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
545 ret = nfserrno(cloned);
548 if (count && cloned != count) {
549 ret = nfserrno(-EINVAL);
553 loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
554 int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
557 status = commit_inode_metadata(file_inode(src));
559 nfsd_reset_boot_verifier(net_generic(nf_dst->nf_net,
561 ret = nfserrno(status);
565 up_write(&nf_dst->nf_rwsem);
569 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
570 u64 dst_pos, u64 count)
574 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
575 * thread and client rpc slot. The choice of 4MB is somewhat
576 * arbitrary. We might instead base this on r/wsize, or make it
577 * tunable, or use a time instead of a byte limit, or implement
578 * asynchronous copy. In theory a client could also recognize a
579 * limit like this and pipeline multiple COPY requests.
581 count = min_t(u64, count, 1 << 22);
582 return vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
585 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
586 struct file *file, loff_t offset, loff_t len,
591 if (!S_ISREG(file_inode(file)->i_mode))
594 error = vfs_fallocate(file, flags, offset, len);
596 error = commit_metadata(fhp);
598 return nfserrno(error);
600 #endif /* defined(CONFIG_NFSD_V4) */
602 #ifdef CONFIG_NFSD_V3
604 * Check server access rights to a file system object
610 static struct accessmap nfs3_regaccess[] = {
611 { NFS3_ACCESS_READ, NFSD_MAY_READ },
612 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
613 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
614 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
616 #ifdef CONFIG_NFSD_V4
617 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
618 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
619 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
625 static struct accessmap nfs3_diraccess[] = {
626 { NFS3_ACCESS_READ, NFSD_MAY_READ },
627 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
628 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
629 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
630 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
632 #ifdef CONFIG_NFSD_V4
633 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
634 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
635 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
641 static struct accessmap nfs3_anyaccess[] = {
642 /* Some clients - Solaris 2.6 at least, make an access call
643 * to the server to check for access for things like /dev/null
644 * (which really, the server doesn't care about). So
645 * We provide simple access checking for them, looking
646 * mainly at mode bits, and we make sure to ignore read-only
649 { NFS3_ACCESS_READ, NFSD_MAY_READ },
650 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
651 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
652 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
658 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
660 struct accessmap *map;
661 struct svc_export *export;
662 struct dentry *dentry;
663 u32 query, result = 0, sresult = 0;
666 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
670 export = fhp->fh_export;
671 dentry = fhp->fh_dentry;
673 if (d_is_reg(dentry))
674 map = nfs3_regaccess;
675 else if (d_is_dir(dentry))
676 map = nfs3_diraccess;
678 map = nfs3_anyaccess;
682 for (; map->access; map++) {
683 if (map->access & query) {
686 sresult |= map->access;
688 err2 = nfsd_permission(rqstp, export, dentry, map->how);
691 result |= map->access;
694 /* the following error codes just mean the access was not allowed,
695 * rather than an error occurred */
699 /* simply don't "or" in the access bit. */
709 *supported = sresult;
714 #endif /* CONFIG_NFSD_V3 */
716 int nfsd_open_break_lease(struct inode *inode, int access)
720 if (access & NFSD_MAY_NOT_BREAK_LEASE)
722 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
723 return break_lease(inode, mode | O_NONBLOCK);
727 * Open an existing file or directory.
728 * The may_flags argument indicates the type of open (read/write/lock)
729 * and additional flags.
730 * N.B. After this call fhp needs an fh_put
733 __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
734 int may_flags, struct file **filp)
739 int flags = O_RDONLY|O_LARGEFILE;
743 path.mnt = fhp->fh_export->ex_path.mnt;
744 path.dentry = fhp->fh_dentry;
745 inode = d_inode(path.dentry);
747 /* Disallow write access to files with the append-only bit set
748 * or any access when mandatory locking enabled
751 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
754 * We must ignore files (but only files) which might have mandatory
755 * locks on them because there is no way to know if the accesser has
758 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
764 host_err = nfsd_open_break_lease(inode, may_flags);
765 if (host_err) /* NOMEM or WOULDBLOCK */
768 if (may_flags & NFSD_MAY_WRITE) {
769 if (may_flags & NFSD_MAY_READ)
770 flags = O_RDWR|O_LARGEFILE;
772 flags = O_WRONLY|O_LARGEFILE;
775 file = dentry_open(&path, flags, current_cred());
777 host_err = PTR_ERR(file);
781 host_err = ima_file_check(file, may_flags);
787 if (may_flags & NFSD_MAY_64BIT_COOKIE)
788 file->f_mode |= FMODE_64BITHASH;
790 file->f_mode |= FMODE_32BITHASH;
794 err = nfserrno(host_err);
800 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
801 int may_flags, struct file **filp)
805 validate_process_creds();
807 * If we get here, then the client has already done an "open",
808 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
809 * in case a chmod has now revoked permission.
811 * Arguably we should also allow the owner override for
812 * directories, but we never have and it doesn't seem to have
813 * caused anyone a problem. If we were to change this, note
814 * also that our filldir callbacks would need a variant of
815 * lookup_one_len that doesn't check permissions.
818 may_flags |= NFSD_MAY_OWNER_OVERRIDE;
819 err = fh_verify(rqstp, fhp, type, may_flags);
821 err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
822 validate_process_creds();
827 nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
828 int may_flags, struct file **filp)
832 validate_process_creds();
833 err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
834 validate_process_creds();
839 * Grab and keep cached pages associated with a file in the svc_rqst
840 * so that they can be passed to the network sendmsg/sendpage routines
841 * directly. They will be released after the sending has completed.
844 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
845 struct splice_desc *sd)
847 struct svc_rqst *rqstp = sd->u.data;
848 struct page **pp = rqstp->rq_next_page;
849 struct page *page = buf->page;
851 if (rqstp->rq_res.page_len == 0) {
853 put_page(*rqstp->rq_next_page);
854 *(rqstp->rq_next_page++) = page;
855 rqstp->rq_res.page_base = buf->offset;
856 } else if (page != pp[-1]) {
858 if (*rqstp->rq_next_page)
859 put_page(*rqstp->rq_next_page);
860 *(rqstp->rq_next_page++) = page;
862 rqstp->rq_res.page_len += sd->len;
867 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
868 struct splice_desc *sd)
870 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
873 static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
876 if (expected != 0 && len == 0)
878 if (offset+len >= i_size_read(file_inode(file)))
883 static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
884 struct file *file, loff_t offset,
885 unsigned long *count, u32 *eof, ssize_t host_err)
888 nfsd_stats_io_read_add(fhp->fh_export, host_err);
889 *eof = nfsd_eof_on_read(file, offset, host_err, *count);
891 fsnotify_access(file);
892 trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
895 trace_nfsd_read_err(rqstp, fhp, offset, host_err);
896 return nfserrno(host_err);
900 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
901 struct file *file, loff_t offset, unsigned long *count,
904 struct splice_desc sd = {
912 trace_nfsd_read_splice(rqstp, fhp, offset, *count);
913 rqstp->rq_next_page = rqstp->rq_respages + 1;
914 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
915 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
918 __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
919 struct file *file, loff_t offset,
920 struct kvec *vec, int vlen, unsigned long *count,
923 struct iov_iter iter;
924 loff_t ppos = offset;
927 trace_nfsd_read_vector(rqstp, fhp, offset, *count);
928 iov_iter_kvec(&iter, READ, vec, vlen, *count);
929 host_err = vfs_iter_read(file, &iter, &ppos, 0);
930 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
934 * Gathered writes: If another process is currently writing to the file,
935 * there's a high chance this is another nfsd (triggered by a bulk write
936 * from a client's biod). Rather than syncing the file with each write
937 * request, we sleep for 10 msec.
939 * I don't know if this roughly approximates C. Juszak's idea of
940 * gathered writes, but it's a nice and simple solution (IMHO), and it
943 * Note: we do this only in the NFSv2 case, since v3 and higher have a
944 * better tool (separate unstable writes and commits) for solving this
947 static int wait_for_concurrent_writes(struct file *file)
949 struct inode *inode = file_inode(file);
950 static ino_t last_ino;
951 static dev_t last_dev;
954 if (atomic_read(&inode->i_writecount) > 1
955 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
956 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
958 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
961 if (inode->i_state & I_DIRTY) {
962 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
963 err = vfs_fsync(file, 0);
965 last_ino = inode->i_ino;
966 last_dev = inode->i_sb->s_dev;
971 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
972 loff_t offset, struct kvec *vec, int vlen,
973 unsigned long *cnt, int stable,
976 struct file *file = nf->nf_file;
977 struct super_block *sb = file_inode(file)->i_sb;
978 struct svc_export *exp;
979 struct iov_iter iter;
984 unsigned long exp_op_flags = 0;
985 unsigned int pflags = current->flags;
987 bool restore_flags = false;
989 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
992 exp_op_flags = sb->s_export_op->flags;
994 if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&
995 !(exp_op_flags & EXPORT_OP_REMOTE_FS)) {
997 * We want throttling in balance_dirty_pages()
998 * and shrink_inactive_list() to only consider
999 * the backingdev we are writing to, so that nfs to
1000 * localhost doesn't cause nfsd to lock up due to all
1001 * the client's dirty pages or its congested queue.
1003 current->flags |= PF_LOCAL_THROTTLE;
1004 restore_flags = true;
1007 exp = fhp->fh_export;
1008 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
1010 if (!EX_ISSYNC(exp))
1011 stable = NFS_UNSTABLE;
1013 if (stable && !use_wgather)
1016 iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);
1017 if (flags & RWF_SYNC) {
1018 down_write(&nf->nf_rwsem);
1019 host_err = vfs_iter_write(file, &iter, &pos, flags);
1021 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
1023 up_write(&nf->nf_rwsem);
1025 down_read(&nf->nf_rwsem);
1027 nfsd_copy_boot_verifier(verf,
1028 net_generic(SVC_NET(rqstp),
1030 host_err = vfs_iter_write(file, &iter, &pos, flags);
1031 up_read(&nf->nf_rwsem);
1034 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
1039 nfsd_stats_io_write_add(exp, *cnt);
1040 fsnotify_modify(file);
1042 if (stable && use_wgather) {
1043 host_err = wait_for_concurrent_writes(file);
1045 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
1050 if (host_err >= 0) {
1051 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
1054 trace_nfsd_write_err(rqstp, fhp, offset, host_err);
1055 nfserr = nfserrno(host_err);
1058 current_restore_flags(pflags, PF_LOCAL_THROTTLE);
1063 * Read data from a file. count must contain the requested read count
1064 * on entry. On return, *count contains the number of bytes actually read.
1065 * N.B. After this call fhp needs an fh_put
1067 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1068 loff_t offset, struct kvec *vec, int vlen, unsigned long *count,
1071 struct nfsd_file *nf;
1075 trace_nfsd_read_start(rqstp, fhp, offset, *count);
1076 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
1081 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
1082 err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
1084 err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count, eof);
1088 trace_nfsd_read_done(rqstp, fhp, offset, *count);
1094 * Write data to a file.
1095 * The stable flag requests synchronous writes.
1096 * N.B. After this call fhp needs an fh_put
1099 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
1100 struct kvec *vec, int vlen, unsigned long *cnt, int stable,
1103 struct nfsd_file *nf;
1106 trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
1108 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_WRITE, &nf);
1112 err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,
1113 vlen, cnt, stable, verf);
1116 trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
1120 #ifdef CONFIG_NFSD_V3
1122 nfsd_filemap_write_and_wait_range(struct nfsd_file *nf, loff_t offset,
1125 struct address_space *mapping = nf->nf_file->f_mapping;
1126 int ret = filemap_fdatawrite_range(mapping, offset, end);
1130 filemap_fdatawait_range_keep_errors(mapping, offset, end);
1135 * Commit all pending writes to stable storage.
1137 * Note: we only guarantee that data that lies within the range specified
1138 * by the 'offset' and 'count' parameters will be synced.
1140 * Unfortunately we cannot lock the file to make sure we return full WCC
1141 * data to the client, as locking happens lower down in the filesystem.
1144 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1145 loff_t offset, unsigned long count, __be32 *verf)
1147 struct nfsd_file *nf;
1148 loff_t end = LLONG_MAX;
1149 __be32 err = nfserr_inval;
1154 end = offset + (loff_t)count - 1;
1159 err = nfsd_file_acquire(rqstp, fhp,
1160 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &nf);
1163 if (EX_ISSYNC(fhp->fh_export)) {
1164 int err2 = nfsd_filemap_write_and_wait_range(nf, offset, end);
1166 down_write(&nf->nf_rwsem);
1168 err2 = vfs_fsync_range(nf->nf_file, offset, end, 0);
1171 nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net,
1175 err = nfserr_notsupp;
1178 err = nfserrno(err2);
1179 nfsd_reset_boot_verifier(net_generic(nf->nf_net,
1182 up_write(&nf->nf_rwsem);
1184 nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net,
1191 #endif /* CONFIG_NFSD_V3 */
1194 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1198 * Mode has already been set earlier in create:
1200 iap->ia_valid &= ~ATTR_MODE;
1202 * Setting uid/gid works only for root. Irix appears to
1203 * send along the gid on create when it tries to implement
1204 * setgid directories via NFS:
1206 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1207 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1209 return nfsd_setattr(rqstp, resfhp, iap, 0, (time64_t)0);
1210 /* Callers expect file metadata to be committed here */
1211 return nfserrno(commit_metadata(resfhp));
1214 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1215 * setting size to 0 may fail for some specific file systems by the permission
1216 * checking which requires WRITE permission but the mode is 000.
1217 * we ignore the resizing(to 0) on the just new created file, since the size is
1218 * 0 after file created.
1220 * call this only after vfs_create() is called.
1223 nfsd_check_ignore_resizing(struct iattr *iap)
1225 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1226 iap->ia_valid &= ~ATTR_SIZE;
1229 /* The parent directory should already be locked: */
1231 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
1232 char *fname, int flen, struct iattr *iap,
1233 int type, dev_t rdev, struct svc_fh *resfhp)
1235 struct dentry *dentry, *dchild;
1241 dentry = fhp->fh_dentry;
1242 dirp = d_inode(dentry);
1244 dchild = dget(resfhp->fh_dentry);
1245 if (!fhp->fh_locked) {
1246 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
1252 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
1256 if (!(iap->ia_valid & ATTR_MODE))
1258 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1260 if (!IS_POSIXACL(dirp))
1261 iap->ia_mode &= ~current_umask();
1267 host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true);
1269 nfsd_check_ignore_resizing(iap);
1272 host_err = vfs_mkdir(&init_user_ns, dirp, dchild, iap->ia_mode);
1273 if (!host_err && unlikely(d_unhashed(dchild))) {
1275 d = lookup_one_len(dchild->d_name.name,
1277 dchild->d_name.len);
1279 host_err = PTR_ERR(d);
1282 if (unlikely(d_is_negative(d))) {
1284 err = nfserr_serverfault;
1287 dput(resfhp->fh_dentry);
1288 resfhp->fh_dentry = dget(d);
1289 err = fh_update(resfhp);
1300 host_err = vfs_mknod(&init_user_ns, dirp, dchild,
1301 iap->ia_mode, rdev);
1304 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1311 err = nfsd_create_setattr(rqstp, resfhp, iap);
1314 * nfsd_create_setattr already committed the child. Transactional
1315 * filesystems had a chance to commit changes for both parent and
1316 * child simultaneously making the following commit_metadata a
1319 err2 = nfserrno(commit_metadata(fhp));
1323 * Update the file handle to get the new inode info.
1326 err = fh_update(resfhp);
1332 err = nfserrno(host_err);
1337 * Create a filesystem object (regular, directory, special).
1338 * Note that the parent directory is left locked.
1340 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1343 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1344 char *fname, int flen, struct iattr *iap,
1345 int type, dev_t rdev, struct svc_fh *resfhp)
1347 struct dentry *dentry, *dchild = NULL;
1351 if (isdotent(fname, flen))
1352 return nfserr_exist;
1354 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
1358 dentry = fhp->fh_dentry;
1360 host_err = fh_want_write(fhp);
1362 return nfserrno(host_err);
1364 fh_lock_nested(fhp, I_MUTEX_PARENT);
1365 dchild = lookup_one_len(fname, dentry, flen);
1366 host_err = PTR_ERR(dchild);
1368 return nfserrno(host_err);
1369 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1371 * We unconditionally drop our ref to dchild as fh_compose will have
1372 * already grabbed its own ref for it.
1377 return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
1381 #ifdef CONFIG_NFSD_V3
1384 * NFSv3 and NFSv4 version of nfsd_create
1387 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1388 char *fname, int flen, struct iattr *iap,
1389 struct svc_fh *resfhp, int createmode, u32 *verifier,
1390 bool *truncp, bool *created)
1392 struct dentry *dentry, *dchild = NULL;
1396 __u32 v_mtime=0, v_atime=0;
1402 if (isdotent(fname, flen))
1404 if (!(iap->ia_valid & ATTR_MODE))
1406 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
1410 dentry = fhp->fh_dentry;
1411 dirp = d_inode(dentry);
1413 host_err = fh_want_write(fhp);
1417 fh_lock_nested(fhp, I_MUTEX_PARENT);
1420 * Compose the response file handle.
1422 dchild = lookup_one_len(fname, dentry, flen);
1423 host_err = PTR_ERR(dchild);
1427 /* If file doesn't exist, check for permissions to create one */
1428 if (d_really_is_negative(dchild)) {
1429 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1434 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1438 if (nfsd_create_is_exclusive(createmode)) {
1439 /* solaris7 gets confused (bugid 4218508) if these have
1440 * the high bit set, so just clear the high bits. If this is
1441 * ever changed to use different attrs for storing the
1442 * verifier, then do_open_lookup() will also need to be fixed
1445 v_mtime = verifier[0]&0x7fffffff;
1446 v_atime = verifier[1]&0x7fffffff;
1449 if (d_really_is_positive(dchild)) {
1452 switch (createmode) {
1453 case NFS3_CREATE_UNCHECKED:
1454 if (! d_is_reg(dchild))
1457 /* in nfsv4, we need to treat this case a little
1458 * differently. we don't want to truncate the
1459 * file now; this would be wrong if the OPEN
1460 * fails for some other reason. furthermore,
1461 * if the size is nonzero, we should ignore it
1462 * according to spec!
1464 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1467 iap->ia_valid &= ATTR_SIZE;
1471 case NFS3_CREATE_EXCLUSIVE:
1472 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1473 && d_inode(dchild)->i_atime.tv_sec == v_atime
1474 && d_inode(dchild)->i_size == 0 ) {
1480 case NFS4_CREATE_EXCLUSIVE4_1:
1481 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1482 && d_inode(dchild)->i_atime.tv_sec == v_atime
1483 && d_inode(dchild)->i_size == 0 ) {
1489 case NFS3_CREATE_GUARDED:
1496 if (!IS_POSIXACL(dirp))
1497 iap->ia_mode &= ~current_umask();
1499 host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true);
1507 nfsd_check_ignore_resizing(iap);
1509 if (nfsd_create_is_exclusive(createmode)) {
1510 /* Cram the verifier into atime/mtime */
1511 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1512 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1513 /* XXX someone who knows this better please fix it for nsec */
1514 iap->ia_mtime.tv_sec = v_mtime;
1515 iap->ia_atime.tv_sec = v_atime;
1516 iap->ia_mtime.tv_nsec = 0;
1517 iap->ia_atime.tv_nsec = 0;
1521 err = nfsd_create_setattr(rqstp, resfhp, iap);
1524 * nfsd_create_setattr already committed the child
1525 * (and possibly also the parent).
1528 err = nfserrno(commit_metadata(fhp));
1531 * Update the filehandle to get the new inode info.
1534 err = fh_update(resfhp);
1538 if (dchild && !IS_ERR(dchild))
1544 err = nfserrno(host_err);
1547 #endif /* CONFIG_NFSD_V3 */
1550 * Read a symlink. On entry, *lenp must contain the maximum path length that
1551 * fits into the buffer. On return, it contains the true length.
1552 * N.B. After this call fhp needs an fh_put
1555 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1560 DEFINE_DELAYED_CALL(done);
1563 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1567 path.mnt = fhp->fh_export->ex_path.mnt;
1568 path.dentry = fhp->fh_dentry;
1570 if (unlikely(!d_is_symlink(path.dentry)))
1571 return nfserr_inval;
1575 link = vfs_get_link(path.dentry, &done);
1577 return nfserrno(PTR_ERR(link));
1582 memcpy(buf, link, *lenp);
1583 do_delayed_call(&done);
1588 * Create a symlink and look up its inode
1589 * N.B. After this call _both_ fhp and resfhp need an fh_put
1592 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1593 char *fname, int flen,
1595 struct svc_fh *resfhp)
1597 struct dentry *dentry, *dnew;
1602 if (!flen || path[0] == '\0')
1605 if (isdotent(fname, flen))
1608 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1612 host_err = fh_want_write(fhp);
1617 dentry = fhp->fh_dentry;
1618 dnew = lookup_one_len(fname, dentry, flen);
1619 host_err = PTR_ERR(dnew);
1623 host_err = vfs_symlink(&init_user_ns, d_inode(dentry), dnew, path);
1624 err = nfserrno(host_err);
1627 err = nfserrno(commit_metadata(fhp));
1631 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1633 if (err==0) err = cerr;
1638 err = nfserrno(host_err);
1644 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1647 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1648 char *name, int len, struct svc_fh *tfhp)
1650 struct dentry *ddir, *dnew, *dold;
1655 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1658 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1662 if (d_is_dir(tfhp->fh_dentry))
1668 if (isdotent(name, len))
1671 host_err = fh_want_write(tfhp);
1673 err = nfserrno(host_err);
1677 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1678 ddir = ffhp->fh_dentry;
1679 dirp = d_inode(ddir);
1681 dnew = lookup_one_len(name, ddir, len);
1682 host_err = PTR_ERR(dnew);
1686 dold = tfhp->fh_dentry;
1689 if (d_really_is_negative(dold))
1691 host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL);
1694 err = nfserrno(commit_metadata(ffhp));
1696 err = nfserrno(commit_metadata(tfhp));
1698 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1701 err = nfserrno(host_err);
1707 fh_drop_write(tfhp);
1712 err = nfserrno(host_err);
1717 nfsd_close_cached_files(struct dentry *dentry)
1719 struct inode *inode = d_inode(dentry);
1721 if (inode && S_ISREG(inode->i_mode))
1722 nfsd_file_close_inode_sync(inode);
1726 nfsd_has_cached_files(struct dentry *dentry)
1729 struct inode *inode = d_inode(dentry);
1731 if (inode && S_ISREG(inode->i_mode))
1732 ret = nfsd_file_is_cached(inode);
1738 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1741 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1742 struct svc_fh *tfhp, char *tname, int tlen)
1744 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1745 struct inode *fdir, *tdir;
1748 bool close_cached = false;
1750 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1753 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1757 fdentry = ffhp->fh_dentry;
1758 fdir = d_inode(fdentry);
1760 tdentry = tfhp->fh_dentry;
1761 tdir = d_inode(tdentry);
1764 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1768 host_err = fh_want_write(ffhp);
1770 err = nfserrno(host_err);
1774 /* cannot use fh_lock as we need deadlock protective ordering
1775 * so do it by hand */
1776 trap = lock_rename(tdentry, fdentry);
1777 ffhp->fh_locked = tfhp->fh_locked = true;
1781 odentry = lookup_one_len(fname, fdentry, flen);
1782 host_err = PTR_ERR(odentry);
1783 if (IS_ERR(odentry))
1787 if (d_really_is_negative(odentry))
1790 if (odentry == trap)
1793 ndentry = lookup_one_len(tname, tdentry, tlen);
1794 host_err = PTR_ERR(ndentry);
1795 if (IS_ERR(ndentry))
1797 host_err = -ENOTEMPTY;
1798 if (ndentry == trap)
1802 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1804 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
1807 if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) &&
1808 nfsd_has_cached_files(ndentry)) {
1809 close_cached = true;
1812 struct renamedata rd = {
1813 .old_mnt_userns = &init_user_ns,
1815 .old_dentry = odentry,
1816 .new_mnt_userns = &init_user_ns,
1818 .new_dentry = ndentry,
1820 host_err = vfs_rename(&rd);
1822 host_err = commit_metadata(tfhp);
1824 host_err = commit_metadata(ffhp);
1832 err = nfserrno(host_err);
1834 * We cannot rely on fh_unlock on the two filehandles,
1835 * as that would do the wrong thing if the two directories
1836 * were the same, so again we do it by hand.
1838 if (!close_cached) {
1839 fill_post_wcc(ffhp);
1840 fill_post_wcc(tfhp);
1842 unlock_rename(tdentry, fdentry);
1843 ffhp->fh_locked = tfhp->fh_locked = false;
1844 fh_drop_write(ffhp);
1847 * If the target dentry has cached open files, then we need to try to
1848 * close them prior to doing the rename. Flushing delayed fput
1849 * shouldn't be done with locks held however, so we delay it until this
1850 * point and then reattempt the whole shebang.
1853 close_cached = false;
1854 nfsd_close_cached_files(ndentry);
1863 * Unlink a file or directory
1864 * N.B. After this call fhp needs an fh_put
1867 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1868 char *fname, int flen)
1870 struct dentry *dentry, *rdentry;
1872 struct inode *rinode;
1877 if (!flen || isdotent(fname, flen))
1879 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1883 host_err = fh_want_write(fhp);
1887 fh_lock_nested(fhp, I_MUTEX_PARENT);
1888 dentry = fhp->fh_dentry;
1889 dirp = d_inode(dentry);
1891 rdentry = lookup_one_len(fname, dentry, flen);
1892 host_err = PTR_ERR(rdentry);
1893 if (IS_ERR(rdentry))
1894 goto out_drop_write;
1896 if (d_really_is_negative(rdentry)) {
1899 goto out_drop_write;
1901 rinode = d_inode(rdentry);
1905 type = d_inode(rdentry)->i_mode & S_IFMT;
1907 if (type != S_IFDIR) {
1908 if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK)
1909 nfsd_close_cached_files(rdentry);
1910 host_err = vfs_unlink(&init_user_ns, dirp, rdentry, NULL);
1912 host_err = vfs_rmdir(&init_user_ns, dirp, rdentry);
1917 host_err = commit_metadata(fhp);
1919 iput(rinode); /* truncate the inode here */
1924 if (host_err == -EBUSY) {
1925 /* name is mounted-on. There is no perfect
1928 if (nfsd_v4client(rqstp))
1929 err = nfserr_file_open;
1933 err = nfserrno(host_err);
1940 * We do this buffering because we must not call back into the file
1941 * system's ->lookup() method from the filldir callback. That may well
1942 * deadlock a number of file systems.
1944 * This is based heavily on the implementation of same in XFS.
1946 struct buffered_dirent {
1950 unsigned int d_type;
1954 struct readdir_data {
1955 struct dir_context ctx;
1961 static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
1962 int namlen, loff_t offset, u64 ino,
1963 unsigned int d_type)
1965 struct readdir_data *buf =
1966 container_of(ctx, struct readdir_data, ctx);
1967 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1968 unsigned int reclen;
1970 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1971 if (buf->used + reclen > PAGE_SIZE) {
1976 de->namlen = namlen;
1977 de->offset = offset;
1979 de->d_type = d_type;
1980 memcpy(de->name, name, namlen);
1981 buf->used += reclen;
1986 static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,
1987 nfsd_filldir_t func, struct readdir_cd *cdp,
1990 struct buffered_dirent *de;
1994 struct readdir_data buf = {
1995 .ctx.actor = nfsd_buffered_filldir,
1996 .dirent = (void *)__get_free_page(GFP_KERNEL)
2000 return nfserrno(-ENOMEM);
2005 unsigned int reclen;
2007 cdp->err = nfserr_eof; /* will be cleared on successful read */
2011 host_err = iterate_dir(file, &buf.ctx);
2023 de = (struct buffered_dirent *)buf.dirent;
2025 offset = de->offset;
2027 if (func(cdp, de->name, de->namlen, de->offset,
2028 de->ino, de->d_type))
2031 if (cdp->err != nfs_ok)
2034 trace_nfsd_dirent(fhp, de->ino, de->name, de->namlen);
2036 reclen = ALIGN(sizeof(*de) + de->namlen,
2039 de = (struct buffered_dirent *)((char *)de + reclen);
2041 if (size > 0) /* We bailed out early */
2044 offset = vfs_llseek(file, 0, SEEK_CUR);
2047 free_page((unsigned long)(buf.dirent));
2050 return nfserrno(host_err);
2057 * Read entries from a directory.
2058 * The NFSv3/4 verifier we ignore for now.
2061 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
2062 struct readdir_cd *cdp, nfsd_filldir_t func)
2066 loff_t offset = *offsetp;
2067 int may_flags = NFSD_MAY_READ;
2069 /* NFSv2 only supports 32 bit cookies */
2070 if (rqstp->rq_vers > 2)
2071 may_flags |= NFSD_MAY_64BIT_COOKIE;
2073 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
2077 offset = vfs_llseek(file, offset, SEEK_SET);
2079 err = nfserrno((int)offset);
2083 err = nfsd_buffered_readdir(file, fhp, func, cdp, offsetp);
2085 if (err == nfserr_eof || err == nfserr_toosmall)
2086 err = nfs_ok; /* can still be found in ->err */
2094 * Get file system stats
2095 * N.B. After this call fhp needs an fh_put
2098 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
2102 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
2104 struct path path = {
2105 .mnt = fhp->fh_export->ex_path.mnt,
2106 .dentry = fhp->fh_dentry,
2108 if (vfs_statfs(&path, stat))
2114 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
2116 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
2119 #ifdef CONFIG_NFSD_V4
2121 * Helper function to translate error numbers. In the case of xattr operations,
2122 * some error codes need to be translated outside of the standard translations.
2124 * ENODATA needs to be translated to nfserr_noxattr.
2125 * E2BIG to nfserr_xattr2big.
2127 * Additionally, vfs_listxattr can return -ERANGE. This means that the
2128 * file has too many extended attributes to retrieve inside an
2129 * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
2130 * filesystems will allow the adding of extended attributes until they hit
2131 * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
2132 * So, at that point, the attributes are present and valid, but can't
2133 * be retrieved using listxattr, since the upper level xattr code enforces
2134 * the XATTR_LIST_MAX limit.
2136 * This bug means that we need to deal with listxattr returning -ERANGE. The
2137 * best mapping is to return TOOSMALL.
2140 nfsd_xattr_errno(int err)
2144 return nfserr_noxattr;
2146 return nfserr_xattr2big;
2148 return nfserr_toosmall;
2150 return nfserrno(err);
2154 * Retrieve the specified user extended attribute. To avoid always
2155 * having to allocate the maximum size (since we are not getting
2156 * a maximum size from the RPC), do a probe + alloc. Hold a reader
2157 * lock on i_rwsem to prevent the extended attribute from changing
2158 * size while we're doing this.
2161 nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2162 void **bufp, int *lenp)
2167 struct inode *inode;
2168 struct dentry *dentry;
2170 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2175 dentry = fhp->fh_dentry;
2176 inode = d_inode(dentry);
2178 inode_lock_shared(inode);
2180 len = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0);
2183 * Zero-length attribute, just return.
2192 err = nfsd_xattr_errno(len);
2197 err = nfserr_toosmall;
2201 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2203 err = nfserr_jukebox;
2207 len = vfs_getxattr(&init_user_ns, dentry, name, buf, len);
2211 err = nfsd_xattr_errno(len);
2218 inode_unlock_shared(inode);
2224 * Retrieve the xattr names. Since we can't know how many are
2225 * user extended attributes, we must get all attributes here,
2226 * and have the XDR encode filter out the "user." ones.
2228 * While this could always just allocate an XATTR_LIST_MAX
2229 * buffer, that's a waste, so do a probe + allocate. To
2230 * avoid any changes between the probe and allocate, wrap
2231 * this in inode_lock.
2234 nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
2240 struct inode *inode;
2241 struct dentry *dentry;
2243 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2247 dentry = fhp->fh_dentry;
2248 inode = d_inode(dentry);
2251 inode_lock_shared(inode);
2253 len = vfs_listxattr(dentry, NULL, 0);
2255 err = nfsd_xattr_errno(len);
2259 if (len > XATTR_LIST_MAX) {
2260 err = nfserr_xattr2big;
2265 * We're holding i_rwsem - use GFP_NOFS.
2267 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2269 err = nfserr_jukebox;
2273 len = vfs_listxattr(dentry, buf, len);
2276 err = nfsd_xattr_errno(len);
2285 inode_unlock_shared(inode);
2291 * Removexattr and setxattr need to call fh_lock to both lock the inode
2292 * and set the change attribute. Since the top-level vfs_removexattr
2293 * and vfs_setxattr calls already do their own inode_lock calls, call
2294 * the _locked variant. Pass in a NULL pointer for delegated_inode,
2295 * and let the client deal with NFS4ERR_DELAY (same as with e.g.
2296 * setattr and remove).
2299 nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
2304 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2308 ret = fh_want_write(fhp);
2310 return nfserrno(ret);
2314 ret = __vfs_removexattr_locked(&init_user_ns, fhp->fh_dentry,
2320 return nfsd_xattr_errno(ret);
2324 nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2325 void *buf, u32 len, u32 flags)
2330 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2334 ret = fh_want_write(fhp);
2336 return nfserrno(ret);
2339 ret = __vfs_setxattr_locked(&init_user_ns, fhp->fh_dentry, name, buf,
2345 return nfsd_xattr_errno(ret);
2350 * Check for a user's access permissions to this inode.
2353 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2354 struct dentry *dentry, int acc)
2356 struct inode *inode = d_inode(dentry);
2359 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
2362 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2364 (acc & NFSD_MAY_READ)? " read" : "",
2365 (acc & NFSD_MAY_WRITE)? " write" : "",
2366 (acc & NFSD_MAY_EXEC)? " exec" : "",
2367 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2368 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2369 (acc & NFSD_MAY_LOCK)? " lock" : "",
2370 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2372 IS_IMMUTABLE(inode)? " immut" : "",
2373 IS_APPEND(inode)? " append" : "",
2374 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2375 dprintk(" owner %d/%d user %d/%d\n",
2376 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2379 /* Normally we reject any write/sattr etc access on a read-only file
2380 * system. But if it is IRIX doing check on write-access for a
2381 * device special file, we ignore rofs.
2383 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2384 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2385 if (exp_rdonly(rqstp, exp) ||
2386 __mnt_is_readonly(exp->ex_path.mnt))
2388 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2391 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2394 if (acc & NFSD_MAY_LOCK) {
2395 /* If we cannot rely on authentication in NLM requests,
2396 * just allow locks, otherwise require read permission, or
2399 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2402 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2405 * The file owner always gets access permission for accesses that
2406 * would normally be checked at open time. This is to make
2407 * file access work even when the client has done a fchmod(fd, 0).
2409 * However, `cp foo bar' should fail nevertheless when bar is
2410 * readonly. A sensible way to do this might be to reject all
2411 * attempts to truncate a read-only file, because a creat() call
2412 * always implies file truncation.
2413 * ... but this isn't really fair. A process may reasonably call
2414 * ftruncate on an open file descriptor on a file with perm 000.
2415 * We must trust the client to do permission checking - using "ACCESS"
2418 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2419 uid_eq(inode->i_uid, current_fsuid()))
2422 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2423 err = inode_permission(&init_user_ns, inode,
2424 acc & (MAY_READ | MAY_WRITE | MAY_EXEC));
2426 /* Allow read access to binaries even when mode 111 */
2427 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2428 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2429 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2430 err = inode_permission(&init_user_ns, inode, MAY_EXEC);
2432 return err? nfserrno(err) : 0;