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
249 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
250 unsigned int len, struct svc_fh *resfh)
252 struct svc_export *exp;
253 struct dentry *dentry;
256 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
259 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
262 err = check_nfsd_access(exp, rqstp);
266 * Note: we compose the file handle now, but as the
267 * dentry may be negative, it may need to be updated.
269 err = fh_compose(resfh, exp, dentry, fhp);
270 if (!err && d_really_is_negative(dentry))
279 * Commit metadata changes to stable storage.
282 commit_inode_metadata(struct inode *inode)
284 const struct export_operations *export_ops = inode->i_sb->s_export_op;
286 if (export_ops->commit_metadata)
287 return export_ops->commit_metadata(inode);
288 return sync_inode_metadata(inode, 1);
292 commit_metadata(struct svc_fh *fhp)
294 struct inode *inode = d_inode(fhp->fh_dentry);
296 if (!EX_ISSYNC(fhp->fh_export))
298 return commit_inode_metadata(inode);
302 * Go over the attributes and take care of the small differences between
303 * NFS semantics and what Linux expects.
306 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
308 /* sanitize the mode change */
309 if (iap->ia_valid & ATTR_MODE) {
310 iap->ia_mode &= S_IALLUGO;
311 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
314 /* Revoke setuid/setgid on chown */
315 if (!S_ISDIR(inode->i_mode) &&
316 ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
317 iap->ia_valid |= ATTR_KILL_PRIV;
318 if (iap->ia_valid & ATTR_MODE) {
319 /* we're setting mode too, just clear the s*id bits */
320 iap->ia_mode &= ~S_ISUID;
321 if (iap->ia_mode & S_IXGRP)
322 iap->ia_mode &= ~S_ISGID;
324 /* set ATTR_KILL_* bits and let VFS handle it */
325 iap->ia_valid |= ATTR_KILL_SUID;
327 setattr_should_drop_sgid(&init_user_ns, inode);
333 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
336 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);
346 return nfserrno(get_write_access(inode));
350 * Set various file attributes. After this call fhp needs an fh_put.
353 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
354 int check_guard, time64_t guardtime)
356 struct dentry *dentry;
358 int accmode = NFSD_MAY_SATTR;
362 bool get_write_count;
363 bool size_change = (iap->ia_valid & ATTR_SIZE);
365 if (iap->ia_valid & ATTR_SIZE) {
366 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
371 * If utimes(2) and friends are called with times not NULL, we should
372 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
373 * will return EACCES, when the caller's effective UID does not match
374 * the owner of the file, and the caller is not privileged. In this
375 * situation, we should return EPERM(notify_change will return this).
377 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) {
378 accmode |= NFSD_MAY_OWNER_OVERRIDE;
379 if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET)))
380 accmode |= NFSD_MAY_WRITE;
383 /* Callers that do fh_verify should do the fh_want_write: */
384 get_write_count = !fhp->fh_dentry;
387 err = fh_verify(rqstp, fhp, ftype, accmode);
390 if (get_write_count) {
391 host_err = fh_want_write(fhp);
396 dentry = fhp->fh_dentry;
397 inode = d_inode(dentry);
399 /* Ignore any mode updates on symlinks */
400 if (S_ISLNK(inode->i_mode))
401 iap->ia_valid &= ~ATTR_MODE;
406 nfsd_sanitize_attrs(inode, iap);
408 if (check_guard && guardtime != inode->i_ctime.tv_sec)
409 return nfserr_notsync;
412 * The size case is special, it changes the file in addition to the
413 * attributes, and file systems don't expect it to be mixed with
414 * "random" attribute changes. We thus split out the size change
415 * into a separate call to ->setattr, and do the rest as a separate
419 err = nfsd_get_write_access(rqstp, fhp, iap);
427 * RFC5661, Section 18.30.4:
428 * Changing the size of a file with SETATTR indirectly
429 * changes the time_modify and change attributes.
431 * (and similar for the older RFCs)
433 struct iattr size_attr = {
434 .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
435 .ia_size = iap->ia_size,
439 if (iap->ia_size < 0)
442 host_err = notify_change(&init_user_ns, dentry, &size_attr, NULL);
445 iap->ia_valid &= ~ATTR_SIZE;
448 * Avoid the additional setattr call below if the only other
449 * attribute that the client sends is the mtime, as we update
450 * it as part of the size change above.
452 if ((iap->ia_valid & ~ATTR_MTIME) == 0)
456 iap->ia_valid |= ATTR_CTIME;
457 host_err = notify_change(&init_user_ns, dentry, iap, NULL);
462 put_write_access(inode);
465 host_err = commit_metadata(fhp);
466 return nfserrno(host_err);
469 #if defined(CONFIG_NFSD_V4)
471 * NFS junction information is stored in an extended attribute.
473 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
476 * nfsd4_is_junction - Test if an object could be an NFS junction
478 * @dentry: object to test
480 * Returns 1 if "dentry" appears to contain NFS junction information.
481 * Otherwise 0 is returned.
483 int nfsd4_is_junction(struct dentry *dentry)
485 struct inode *inode = d_inode(dentry);
489 if (inode->i_mode & S_IXUGO)
491 if (!(inode->i_mode & S_ISVTX))
493 if (vfs_getxattr(&init_user_ns, dentry, NFSD_JUNCTION_XATTR_NAME,
498 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
499 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
500 struct xdr_netobj *label)
504 struct dentry *dentry;
506 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
510 dentry = fhp->fh_dentry;
512 inode_lock(d_inode(dentry));
513 host_error = security_inode_setsecctx(dentry, label->data, label->len);
514 inode_unlock(d_inode(dentry));
515 return nfserrno(host_error);
518 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
519 struct xdr_netobj *label)
521 return nfserr_notsupp;
525 __be32 nfsd4_clone_file_range(struct nfsd_file *nf_src, u64 src_pos,
526 struct nfsd_file *nf_dst, u64 dst_pos, u64 count, bool sync)
528 struct file *src = nf_src->nf_file;
529 struct file *dst = nf_dst->nf_file;
534 since = READ_ONCE(dst->f_wb_err);
535 cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
537 ret = nfserrno(cloned);
540 if (count && cloned != count) {
541 ret = nfserrno(-EINVAL);
545 loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
546 int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
549 status = filemap_check_wb_err(dst->f_mapping, since);
551 status = commit_inode_metadata(file_inode(src));
553 nfsd_reset_boot_verifier(net_generic(nf_dst->nf_net,
555 ret = nfserrno(status);
562 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
563 u64 dst_pos, u64 count)
568 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
569 * thread and client rpc slot. The choice of 4MB is somewhat
570 * arbitrary. We might instead base this on r/wsize, or make it
571 * tunable, or use a time instead of a byte limit, or implement
572 * asynchronous copy. In theory a client could also recognize a
573 * limit like this and pipeline multiple COPY requests.
575 count = min_t(u64, count, 1 << 22);
576 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
578 if (ret == -EOPNOTSUPP || ret == -EXDEV)
579 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count,
584 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
585 struct file *file, loff_t offset, loff_t len,
590 if (!S_ISREG(file_inode(file)->i_mode))
593 error = vfs_fallocate(file, flags, offset, len);
595 error = commit_metadata(fhp);
597 return nfserrno(error);
599 #endif /* defined(CONFIG_NFSD_V4) */
601 #ifdef CONFIG_NFSD_V3
603 * Check server access rights to a file system object
609 static struct accessmap nfs3_regaccess[] = {
610 { NFS3_ACCESS_READ, NFSD_MAY_READ },
611 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
612 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
613 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
615 #ifdef CONFIG_NFSD_V4
616 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
617 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
618 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
624 static struct accessmap nfs3_diraccess[] = {
625 { NFS3_ACCESS_READ, NFSD_MAY_READ },
626 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
627 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
628 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
629 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
631 #ifdef CONFIG_NFSD_V4
632 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
633 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
634 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
640 static struct accessmap nfs3_anyaccess[] = {
641 /* Some clients - Solaris 2.6 at least, make an access call
642 * to the server to check for access for things like /dev/null
643 * (which really, the server doesn't care about). So
644 * We provide simple access checking for them, looking
645 * mainly at mode bits, and we make sure to ignore read-only
648 { NFS3_ACCESS_READ, NFSD_MAY_READ },
649 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
650 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
651 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
657 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
659 struct accessmap *map;
660 struct svc_export *export;
661 struct dentry *dentry;
662 u32 query, result = 0, sresult = 0;
665 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
669 export = fhp->fh_export;
670 dentry = fhp->fh_dentry;
672 if (d_is_reg(dentry))
673 map = nfs3_regaccess;
674 else if (d_is_dir(dentry))
675 map = nfs3_diraccess;
677 map = nfs3_anyaccess;
681 for (; map->access; map++) {
682 if (map->access & query) {
685 sresult |= map->access;
687 err2 = nfsd_permission(rqstp, export, dentry, map->how);
690 result |= map->access;
693 /* the following error codes just mean the access was not allowed,
694 * rather than an error occurred */
698 /* simply don't "or" in the access bit. */
708 *supported = sresult;
713 #endif /* CONFIG_NFSD_V3 */
715 int nfsd_open_break_lease(struct inode *inode, int access)
719 if (access & NFSD_MAY_NOT_BREAK_LEASE)
721 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
722 return break_lease(inode, mode | O_NONBLOCK);
726 * Open an existing file or directory.
727 * The may_flags argument indicates the type of open (read/write/lock)
728 * and additional flags.
729 * N.B. After this call fhp needs an fh_put
732 __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
733 int may_flags, struct file **filp)
738 int flags = O_RDONLY|O_LARGEFILE;
742 path.mnt = fhp->fh_export->ex_path.mnt;
743 path.dentry = fhp->fh_dentry;
744 inode = d_inode(path.dentry);
746 /* Disallow write access to files with the append-only bit set
747 * or any access when mandatory locking enabled
750 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
756 host_err = nfsd_open_break_lease(inode, may_flags);
757 if (host_err) /* NOMEM or WOULDBLOCK */
760 if (may_flags & NFSD_MAY_WRITE) {
761 if (may_flags & NFSD_MAY_READ)
762 flags = O_RDWR|O_LARGEFILE;
764 flags = O_WRONLY|O_LARGEFILE;
767 file = dentry_open(&path, flags, current_cred());
769 host_err = PTR_ERR(file);
773 host_err = ima_file_check(file, may_flags);
779 if (may_flags & NFSD_MAY_64BIT_COOKIE)
780 file->f_mode |= FMODE_64BITHASH;
782 file->f_mode |= FMODE_32BITHASH;
786 err = nfserrno(host_err);
792 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
793 int may_flags, struct file **filp)
797 validate_process_creds();
799 * If we get here, then the client has already done an "open",
800 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
801 * in case a chmod has now revoked permission.
803 * Arguably we should also allow the owner override for
804 * directories, but we never have and it doesn't seem to have
805 * caused anyone a problem. If we were to change this, note
806 * also that our filldir callbacks would need a variant of
807 * lookup_one_len that doesn't check permissions.
810 may_flags |= NFSD_MAY_OWNER_OVERRIDE;
811 err = fh_verify(rqstp, fhp, type, may_flags);
813 err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
814 validate_process_creds();
819 nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
820 int may_flags, struct file **filp)
824 validate_process_creds();
825 err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
826 validate_process_creds();
831 * Grab and keep cached pages associated with a file in the svc_rqst
832 * so that they can be passed to the network sendmsg/sendpage routines
833 * directly. They will be released after the sending has completed.
836 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
837 struct splice_desc *sd)
839 struct svc_rqst *rqstp = sd->u.data;
840 struct page **pp = rqstp->rq_next_page;
841 struct page *page = buf->page;
843 if (rqstp->rq_res.page_len == 0) {
844 svc_rqst_replace_page(rqstp, page);
845 rqstp->rq_res.page_base = buf->offset;
846 } else if (page != pp[-1]) {
847 svc_rqst_replace_page(rqstp, page);
849 rqstp->rq_res.page_len += sd->len;
854 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
855 struct splice_desc *sd)
857 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
860 static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
863 if (expected != 0 && len == 0)
865 if (offset+len >= i_size_read(file_inode(file)))
870 static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
871 struct file *file, loff_t offset,
872 unsigned long *count, u32 *eof, ssize_t host_err)
875 nfsd_stats_io_read_add(fhp->fh_export, host_err);
876 *eof = nfsd_eof_on_read(file, offset, host_err, *count);
878 fsnotify_access(file);
879 trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
882 trace_nfsd_read_err(rqstp, fhp, offset, host_err);
883 return nfserrno(host_err);
887 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
888 struct file *file, loff_t offset, unsigned long *count,
891 struct splice_desc sd = {
899 trace_nfsd_read_splice(rqstp, fhp, offset, *count);
900 rqstp->rq_next_page = rqstp->rq_respages + 1;
901 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
902 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
905 __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
906 struct file *file, loff_t offset,
907 struct kvec *vec, int vlen, unsigned long *count,
910 struct iov_iter iter;
911 loff_t ppos = offset;
914 trace_nfsd_read_vector(rqstp, fhp, offset, *count);
915 iov_iter_kvec(&iter, READ, vec, vlen, *count);
916 host_err = vfs_iter_read(file, &iter, &ppos, 0);
917 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
921 * Gathered writes: If another process is currently writing to the file,
922 * there's a high chance this is another nfsd (triggered by a bulk write
923 * from a client's biod). Rather than syncing the file with each write
924 * request, we sleep for 10 msec.
926 * I don't know if this roughly approximates C. Juszak's idea of
927 * gathered writes, but it's a nice and simple solution (IMHO), and it
930 * Note: we do this only in the NFSv2 case, since v3 and higher have a
931 * better tool (separate unstable writes and commits) for solving this
934 static int wait_for_concurrent_writes(struct file *file)
936 struct inode *inode = file_inode(file);
937 static ino_t last_ino;
938 static dev_t last_dev;
941 if (atomic_read(&inode->i_writecount) > 1
942 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
943 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
945 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
948 if (inode->i_state & I_DIRTY) {
949 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
950 err = vfs_fsync(file, 0);
952 last_ino = inode->i_ino;
953 last_dev = inode->i_sb->s_dev;
958 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
959 loff_t offset, struct kvec *vec, int vlen,
960 unsigned long *cnt, int stable,
963 struct file *file = nf->nf_file;
964 struct super_block *sb = file_inode(file)->i_sb;
965 struct svc_export *exp;
966 struct iov_iter iter;
972 unsigned long exp_op_flags = 0;
973 unsigned int pflags = current->flags;
975 bool restore_flags = false;
977 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
980 exp_op_flags = sb->s_export_op->flags;
982 if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&
983 !(exp_op_flags & EXPORT_OP_REMOTE_FS)) {
985 * We want throttling in balance_dirty_pages()
986 * and shrink_inactive_list() to only consider
987 * the backingdev we are writing to, so that nfs to
988 * localhost doesn't cause nfsd to lock up due to all
989 * the client's dirty pages or its congested queue.
991 current->flags |= PF_LOCAL_THROTTLE;
992 restore_flags = true;
995 exp = fhp->fh_export;
996 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
999 stable = NFS_UNSTABLE;
1001 if (stable && !use_wgather)
1004 iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);
1005 since = READ_ONCE(file->f_wb_err);
1006 if (flags & RWF_SYNC) {
1008 nfsd_copy_boot_verifier(verf,
1009 net_generic(SVC_NET(rqstp),
1011 host_err = vfs_iter_write(file, &iter, &pos, flags);
1013 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
1017 nfsd_copy_boot_verifier(verf,
1018 net_generic(SVC_NET(rqstp),
1020 host_err = vfs_iter_write(file, &iter, &pos, flags);
1023 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
1028 nfsd_stats_io_write_add(exp, *cnt);
1029 fsnotify_modify(file);
1030 host_err = filemap_check_wb_err(file->f_mapping, since);
1034 if (stable && use_wgather) {
1035 host_err = wait_for_concurrent_writes(file);
1037 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
1042 if (host_err >= 0) {
1043 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
1046 trace_nfsd_write_err(rqstp, fhp, offset, host_err);
1047 nfserr = nfserrno(host_err);
1050 current_restore_flags(pflags, PF_LOCAL_THROTTLE);
1055 * Read data from a file. count must contain the requested read count
1056 * on entry. On return, *count contains the number of bytes actually read.
1057 * N.B. After this call fhp needs an fh_put
1059 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1060 loff_t offset, struct kvec *vec, int vlen, unsigned long *count,
1063 struct nfsd_file *nf;
1067 trace_nfsd_read_start(rqstp, fhp, offset, *count);
1068 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
1073 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
1074 err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
1076 err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count, eof);
1080 trace_nfsd_read_done(rqstp, fhp, offset, *count);
1086 * Write data to a file.
1087 * The stable flag requests synchronous writes.
1088 * N.B. After this call fhp needs an fh_put
1091 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
1092 struct kvec *vec, int vlen, unsigned long *cnt, int stable,
1095 struct nfsd_file *nf;
1098 trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
1100 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_WRITE, &nf);
1104 err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,
1105 vlen, cnt, stable, verf);
1108 trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
1112 #ifdef CONFIG_NFSD_V3
1114 * nfsd_commit - Commit pending writes to stable storage
1115 * @rqstp: RPC request being processed
1116 * @fhp: NFS filehandle
1117 * @offset: raw offset from beginning of file
1118 * @count: raw count of bytes to sync
1119 * @verf: filled in with the server's current write verifier
1121 * Note: we guarantee that data that lies within the range specified
1122 * by the 'offset' and 'count' parameters will be synced. The server
1123 * is permitted to sync data that lies outside this range at the
1126 * Unfortunately we cannot lock the file to make sure we return full WCC
1127 * data to the client, as locking happens lower down in the filesystem.
1130 * An nfsstat value in network byte order.
1133 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, u64 offset,
1134 u32 count, __be32 *verf)
1138 struct nfsd_net *nn;
1139 struct nfsd_file *nf;
1142 err = nfsd_file_acquire(rqstp, fhp,
1143 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &nf);
1148 * Convert the client-provided (offset, count) range to a
1149 * (start, end) range. If the client-provided range falls
1150 * outside the maximum file size of the underlying FS,
1151 * clamp the sync range appropriately.
1155 maxbytes = (u64)fhp->fh_dentry->d_sb->s_maxbytes;
1156 if (offset < maxbytes) {
1158 if (count && (offset + count - 1 < maxbytes))
1159 end = offset + count - 1;
1162 nn = net_generic(nf->nf_net, nfsd_net_id);
1163 if (EX_ISSYNC(fhp->fh_export)) {
1164 errseq_t since = READ_ONCE(nf->nf_file->f_wb_err);
1167 err2 = vfs_fsync_range(nf->nf_file, start, end, 0);
1170 nfsd_copy_boot_verifier(verf, nn);
1171 err2 = filemap_check_wb_err(nf->nf_file->f_mapping,
1173 err = nfserrno(err2);
1176 err = nfserr_notsupp;
1179 nfsd_reset_boot_verifier(nn);
1180 err = nfserrno(err2);
1183 nfsd_copy_boot_verifier(verf, nn);
1189 #endif /* CONFIG_NFSD_V3 */
1192 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1196 * Mode has already been set earlier in create:
1198 iap->ia_valid &= ~ATTR_MODE;
1200 * Setting uid/gid works only for root. Irix appears to
1201 * send along the gid on create when it tries to implement
1202 * setgid directories via NFS:
1204 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1205 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1207 return nfsd_setattr(rqstp, resfhp, iap, 0, (time64_t)0);
1208 /* Callers expect file metadata to be committed here */
1209 return nfserrno(commit_metadata(resfhp));
1212 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1213 * setting size to 0 may fail for some specific file systems by the permission
1214 * checking which requires WRITE permission but the mode is 000.
1215 * we ignore the resizing(to 0) on the just new created file, since the size is
1216 * 0 after file created.
1218 * call this only after vfs_create() is called.
1221 nfsd_check_ignore_resizing(struct iattr *iap)
1223 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1224 iap->ia_valid &= ~ATTR_SIZE;
1227 /* The parent directory should already be locked: */
1229 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
1230 char *fname, int flen, struct iattr *iap,
1231 int type, dev_t rdev, struct svc_fh *resfhp)
1233 struct dentry *dentry, *dchild;
1239 dentry = fhp->fh_dentry;
1240 dirp = d_inode(dentry);
1242 dchild = dget(resfhp->fh_dentry);
1243 if (!fhp->fh_locked) {
1244 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
1250 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
1254 if (!(iap->ia_valid & ATTR_MODE))
1256 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1258 if (!IS_POSIXACL(dirp))
1259 iap->ia_mode &= ~current_umask();
1265 host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true);
1267 nfsd_check_ignore_resizing(iap);
1270 host_err = vfs_mkdir(&init_user_ns, dirp, dchild, iap->ia_mode);
1271 if (!host_err && unlikely(d_unhashed(dchild))) {
1273 d = lookup_one_len(dchild->d_name.name,
1275 dchild->d_name.len);
1277 host_err = PTR_ERR(d);
1280 if (unlikely(d_is_negative(d))) {
1282 err = nfserr_serverfault;
1285 dput(resfhp->fh_dentry);
1286 resfhp->fh_dentry = dget(d);
1287 err = fh_update(resfhp);
1298 host_err = vfs_mknod(&init_user_ns, dirp, dchild,
1299 iap->ia_mode, rdev);
1302 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1309 err = nfsd_create_setattr(rqstp, resfhp, iap);
1312 * nfsd_create_setattr already committed the child. Transactional
1313 * filesystems had a chance to commit changes for both parent and
1314 * child simultaneously making the following commit_metadata a
1317 err2 = nfserrno(commit_metadata(fhp));
1321 * Update the file handle to get the new inode info.
1324 err = fh_update(resfhp);
1330 err = nfserrno(host_err);
1335 * Create a filesystem object (regular, directory, special).
1336 * Note that the parent directory is left locked.
1338 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1341 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1342 char *fname, int flen, struct iattr *iap,
1343 int type, dev_t rdev, struct svc_fh *resfhp)
1345 struct dentry *dentry, *dchild = NULL;
1349 if (isdotent(fname, flen))
1350 return nfserr_exist;
1352 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
1356 dentry = fhp->fh_dentry;
1358 host_err = fh_want_write(fhp);
1360 return nfserrno(host_err);
1362 fh_lock_nested(fhp, I_MUTEX_PARENT);
1363 dchild = lookup_one_len(fname, dentry, flen);
1364 host_err = PTR_ERR(dchild);
1366 return nfserrno(host_err);
1367 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1369 * We unconditionally drop our ref to dchild as fh_compose will have
1370 * already grabbed its own ref for it.
1375 return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
1379 #ifdef CONFIG_NFSD_V3
1382 * NFSv3 and NFSv4 version of nfsd_create
1385 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1386 char *fname, int flen, struct iattr *iap,
1387 struct svc_fh *resfhp, int createmode, u32 *verifier,
1388 bool *truncp, bool *created)
1390 struct dentry *dentry, *dchild = NULL;
1394 __u32 v_mtime=0, v_atime=0;
1400 if (isdotent(fname, flen))
1402 if (!(iap->ia_valid & ATTR_MODE))
1404 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
1408 dentry = fhp->fh_dentry;
1409 dirp = d_inode(dentry);
1411 host_err = fh_want_write(fhp);
1415 fh_lock_nested(fhp, I_MUTEX_PARENT);
1418 * Compose the response file handle.
1420 dchild = lookup_one_len(fname, dentry, flen);
1421 host_err = PTR_ERR(dchild);
1425 /* If file doesn't exist, check for permissions to create one */
1426 if (d_really_is_negative(dchild)) {
1427 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1432 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1436 if (nfsd_create_is_exclusive(createmode)) {
1437 /* solaris7 gets confused (bugid 4218508) if these have
1438 * the high bit set, so just clear the high bits. If this is
1439 * ever changed to use different attrs for storing the
1440 * verifier, then do_open_lookup() will also need to be fixed
1443 v_mtime = verifier[0]&0x7fffffff;
1444 v_atime = verifier[1]&0x7fffffff;
1447 if (d_really_is_positive(dchild)) {
1450 switch (createmode) {
1451 case NFS3_CREATE_UNCHECKED:
1452 if (! d_is_reg(dchild))
1455 /* in nfsv4, we need to treat this case a little
1456 * differently. we don't want to truncate the
1457 * file now; this would be wrong if the OPEN
1458 * fails for some other reason. furthermore,
1459 * if the size is nonzero, we should ignore it
1460 * according to spec!
1462 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1465 iap->ia_valid &= ATTR_SIZE;
1469 case NFS3_CREATE_EXCLUSIVE:
1470 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1471 && d_inode(dchild)->i_atime.tv_sec == v_atime
1472 && d_inode(dchild)->i_size == 0 ) {
1478 case NFS4_CREATE_EXCLUSIVE4_1:
1479 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1480 && d_inode(dchild)->i_atime.tv_sec == v_atime
1481 && d_inode(dchild)->i_size == 0 ) {
1487 case NFS3_CREATE_GUARDED:
1494 if (!IS_POSIXACL(dirp))
1495 iap->ia_mode &= ~current_umask();
1497 host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true);
1505 nfsd_check_ignore_resizing(iap);
1507 if (nfsd_create_is_exclusive(createmode)) {
1508 /* Cram the verifier into atime/mtime */
1509 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1510 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1511 /* XXX someone who knows this better please fix it for nsec */
1512 iap->ia_mtime.tv_sec = v_mtime;
1513 iap->ia_atime.tv_sec = v_atime;
1514 iap->ia_mtime.tv_nsec = 0;
1515 iap->ia_atime.tv_nsec = 0;
1519 err = nfsd_create_setattr(rqstp, resfhp, iap);
1522 * nfsd_create_setattr already committed the child
1523 * (and possibly also the parent).
1526 err = nfserrno(commit_metadata(fhp));
1529 * Update the filehandle to get the new inode info.
1532 err = fh_update(resfhp);
1536 if (dchild && !IS_ERR(dchild))
1542 err = nfserrno(host_err);
1545 #endif /* CONFIG_NFSD_V3 */
1548 * Read a symlink. On entry, *lenp must contain the maximum path length that
1549 * fits into the buffer. On return, it contains the true length.
1550 * N.B. After this call fhp needs an fh_put
1553 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1558 DEFINE_DELAYED_CALL(done);
1561 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1565 path.mnt = fhp->fh_export->ex_path.mnt;
1566 path.dentry = fhp->fh_dentry;
1568 if (unlikely(!d_is_symlink(path.dentry)))
1569 return nfserr_inval;
1573 link = vfs_get_link(path.dentry, &done);
1575 return nfserrno(PTR_ERR(link));
1580 memcpy(buf, link, *lenp);
1581 do_delayed_call(&done);
1586 * Create a symlink and look up its inode
1587 * N.B. After this call _both_ fhp and resfhp need an fh_put
1590 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1591 char *fname, int flen,
1593 struct svc_fh *resfhp)
1595 struct dentry *dentry, *dnew;
1600 if (!flen || path[0] == '\0')
1603 if (isdotent(fname, flen))
1606 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1610 host_err = fh_want_write(fhp);
1615 dentry = fhp->fh_dentry;
1616 dnew = lookup_one_len(fname, dentry, flen);
1617 host_err = PTR_ERR(dnew);
1621 host_err = vfs_symlink(&init_user_ns, d_inode(dentry), dnew, path);
1622 err = nfserrno(host_err);
1625 err = nfserrno(commit_metadata(fhp));
1629 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1631 if (err==0) err = cerr;
1636 err = nfserrno(host_err);
1642 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1645 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1646 char *name, int len, struct svc_fh *tfhp)
1648 struct dentry *ddir, *dnew, *dold;
1653 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1656 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1660 if (d_is_dir(tfhp->fh_dentry))
1666 if (isdotent(name, len))
1669 host_err = fh_want_write(tfhp);
1671 err = nfserrno(host_err);
1675 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1676 ddir = ffhp->fh_dentry;
1677 dirp = d_inode(ddir);
1679 dnew = lookup_one_len(name, ddir, len);
1680 host_err = PTR_ERR(dnew);
1684 dold = tfhp->fh_dentry;
1687 if (d_really_is_negative(dold))
1689 host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL);
1692 err = nfserrno(commit_metadata(ffhp));
1694 err = nfserrno(commit_metadata(tfhp));
1696 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1699 err = nfserrno(host_err);
1705 fh_drop_write(tfhp);
1710 err = nfserrno(host_err);
1715 nfsd_close_cached_files(struct dentry *dentry)
1717 struct inode *inode = d_inode(dentry);
1719 if (inode && S_ISREG(inode->i_mode))
1720 nfsd_file_close_inode_sync(inode);
1724 nfsd_has_cached_files(struct dentry *dentry)
1727 struct inode *inode = d_inode(dentry);
1729 if (inode && S_ISREG(inode->i_mode))
1730 ret = nfsd_file_is_cached(inode);
1736 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1739 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1740 struct svc_fh *tfhp, char *tname, int tlen)
1742 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1743 struct inode *fdir, *tdir;
1746 bool close_cached = false;
1748 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1751 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1755 fdentry = ffhp->fh_dentry;
1756 fdir = d_inode(fdentry);
1758 tdentry = tfhp->fh_dentry;
1759 tdir = d_inode(tdentry);
1762 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1766 host_err = fh_want_write(ffhp);
1768 err = nfserrno(host_err);
1772 /* cannot use fh_lock as we need deadlock protective ordering
1773 * so do it by hand */
1774 trap = lock_rename(tdentry, fdentry);
1775 ffhp->fh_locked = tfhp->fh_locked = true;
1779 odentry = lookup_one_len(fname, fdentry, flen);
1780 host_err = PTR_ERR(odentry);
1781 if (IS_ERR(odentry))
1785 if (d_really_is_negative(odentry))
1788 if (odentry == trap)
1791 ndentry = lookup_one_len(tname, tdentry, tlen);
1792 host_err = PTR_ERR(ndentry);
1793 if (IS_ERR(ndentry))
1795 host_err = -ENOTEMPTY;
1796 if (ndentry == trap)
1800 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1802 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
1805 if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) &&
1806 nfsd_has_cached_files(ndentry)) {
1807 close_cached = true;
1810 struct renamedata rd = {
1811 .old_mnt_userns = &init_user_ns,
1813 .old_dentry = odentry,
1814 .new_mnt_userns = &init_user_ns,
1816 .new_dentry = ndentry,
1818 host_err = vfs_rename(&rd);
1820 host_err = commit_metadata(tfhp);
1822 host_err = commit_metadata(ffhp);
1830 err = nfserrno(host_err);
1832 * We cannot rely on fh_unlock on the two filehandles,
1833 * as that would do the wrong thing if the two directories
1834 * were the same, so again we do it by hand.
1836 if (!close_cached) {
1837 fill_post_wcc(ffhp);
1838 fill_post_wcc(tfhp);
1840 unlock_rename(tdentry, fdentry);
1841 ffhp->fh_locked = tfhp->fh_locked = false;
1842 fh_drop_write(ffhp);
1845 * If the target dentry has cached open files, then we need to try to
1846 * close them prior to doing the rename. Flushing delayed fput
1847 * shouldn't be done with locks held however, so we delay it until this
1848 * point and then reattempt the whole shebang.
1851 close_cached = false;
1852 nfsd_close_cached_files(ndentry);
1861 * Unlink a file or directory
1862 * N.B. After this call fhp needs an fh_put
1865 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1866 char *fname, int flen)
1868 struct dentry *dentry, *rdentry;
1870 struct inode *rinode;
1875 if (!flen || isdotent(fname, flen))
1877 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1881 host_err = fh_want_write(fhp);
1885 fh_lock_nested(fhp, I_MUTEX_PARENT);
1886 dentry = fhp->fh_dentry;
1887 dirp = d_inode(dentry);
1889 rdentry = lookup_one_len(fname, dentry, flen);
1890 host_err = PTR_ERR(rdentry);
1891 if (IS_ERR(rdentry))
1892 goto out_drop_write;
1894 if (d_really_is_negative(rdentry)) {
1897 goto out_drop_write;
1899 rinode = d_inode(rdentry);
1903 type = d_inode(rdentry)->i_mode & S_IFMT;
1905 if (type != S_IFDIR) {
1906 if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK)
1907 nfsd_close_cached_files(rdentry);
1908 host_err = vfs_unlink(&init_user_ns, dirp, rdentry, NULL);
1910 host_err = vfs_rmdir(&init_user_ns, dirp, rdentry);
1915 host_err = commit_metadata(fhp);
1917 iput(rinode); /* truncate the inode here */
1922 if (host_err == -EBUSY) {
1923 /* name is mounted-on. There is no perfect
1926 if (nfsd_v4client(rqstp))
1927 err = nfserr_file_open;
1931 err = nfserrno(host_err);
1938 * We do this buffering because we must not call back into the file
1939 * system's ->lookup() method from the filldir callback. That may well
1940 * deadlock a number of file systems.
1942 * This is based heavily on the implementation of same in XFS.
1944 struct buffered_dirent {
1948 unsigned int d_type;
1952 struct readdir_data {
1953 struct dir_context ctx;
1959 static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
1960 int namlen, loff_t offset, u64 ino,
1961 unsigned int d_type)
1963 struct readdir_data *buf =
1964 container_of(ctx, struct readdir_data, ctx);
1965 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1966 unsigned int reclen;
1968 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1969 if (buf->used + reclen > PAGE_SIZE) {
1974 de->namlen = namlen;
1975 de->offset = offset;
1977 de->d_type = d_type;
1978 memcpy(de->name, name, namlen);
1979 buf->used += reclen;
1984 static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,
1985 nfsd_filldir_t func, struct readdir_cd *cdp,
1988 struct buffered_dirent *de;
1992 struct readdir_data buf = {
1993 .ctx.actor = nfsd_buffered_filldir,
1994 .dirent = (void *)__get_free_page(GFP_KERNEL)
1998 return nfserrno(-ENOMEM);
2003 unsigned int reclen;
2005 cdp->err = nfserr_eof; /* will be cleared on successful read */
2009 host_err = iterate_dir(file, &buf.ctx);
2021 de = (struct buffered_dirent *)buf.dirent;
2023 offset = de->offset;
2025 if (func(cdp, de->name, de->namlen, de->offset,
2026 de->ino, de->d_type))
2029 if (cdp->err != nfs_ok)
2032 trace_nfsd_dirent(fhp, de->ino, de->name, de->namlen);
2034 reclen = ALIGN(sizeof(*de) + de->namlen,
2037 de = (struct buffered_dirent *)((char *)de + reclen);
2039 if (size > 0) /* We bailed out early */
2042 offset = vfs_llseek(file, 0, SEEK_CUR);
2045 free_page((unsigned long)(buf.dirent));
2048 return nfserrno(host_err);
2055 * Read entries from a directory.
2056 * The NFSv3/4 verifier we ignore for now.
2059 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
2060 struct readdir_cd *cdp, nfsd_filldir_t func)
2064 loff_t offset = *offsetp;
2065 int may_flags = NFSD_MAY_READ;
2067 /* NFSv2 only supports 32 bit cookies */
2068 if (rqstp->rq_vers > 2)
2069 may_flags |= NFSD_MAY_64BIT_COOKIE;
2071 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
2075 offset = vfs_llseek(file, offset, SEEK_SET);
2077 err = nfserrno((int)offset);
2081 err = nfsd_buffered_readdir(file, fhp, func, cdp, offsetp);
2083 if (err == nfserr_eof || err == nfserr_toosmall)
2084 err = nfs_ok; /* can still be found in ->err */
2092 * Get file system stats
2093 * N.B. After this call fhp needs an fh_put
2096 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
2100 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
2102 struct path path = {
2103 .mnt = fhp->fh_export->ex_path.mnt,
2104 .dentry = fhp->fh_dentry,
2106 if (vfs_statfs(&path, stat))
2112 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
2114 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
2117 #ifdef CONFIG_NFSD_V4
2119 * Helper function to translate error numbers. In the case of xattr operations,
2120 * some error codes need to be translated outside of the standard translations.
2122 * ENODATA needs to be translated to nfserr_noxattr.
2123 * E2BIG to nfserr_xattr2big.
2125 * Additionally, vfs_listxattr can return -ERANGE. This means that the
2126 * file has too many extended attributes to retrieve inside an
2127 * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
2128 * filesystems will allow the adding of extended attributes until they hit
2129 * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
2130 * So, at that point, the attributes are present and valid, but can't
2131 * be retrieved using listxattr, since the upper level xattr code enforces
2132 * the XATTR_LIST_MAX limit.
2134 * This bug means that we need to deal with listxattr returning -ERANGE. The
2135 * best mapping is to return TOOSMALL.
2138 nfsd_xattr_errno(int err)
2142 return nfserr_noxattr;
2144 return nfserr_xattr2big;
2146 return nfserr_toosmall;
2148 return nfserrno(err);
2152 * Retrieve the specified user extended attribute. To avoid always
2153 * having to allocate the maximum size (since we are not getting
2154 * a maximum size from the RPC), do a probe + alloc. Hold a reader
2155 * lock on i_rwsem to prevent the extended attribute from changing
2156 * size while we're doing this.
2159 nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2160 void **bufp, int *lenp)
2165 struct inode *inode;
2166 struct dentry *dentry;
2168 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2173 dentry = fhp->fh_dentry;
2174 inode = d_inode(dentry);
2176 inode_lock_shared(inode);
2178 len = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0);
2181 * Zero-length attribute, just return.
2190 err = nfsd_xattr_errno(len);
2195 err = nfserr_toosmall;
2199 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2201 err = nfserr_jukebox;
2205 len = vfs_getxattr(&init_user_ns, dentry, name, buf, len);
2209 err = nfsd_xattr_errno(len);
2216 inode_unlock_shared(inode);
2222 * Retrieve the xattr names. Since we can't know how many are
2223 * user extended attributes, we must get all attributes here,
2224 * and have the XDR encode filter out the "user." ones.
2226 * While this could always just allocate an XATTR_LIST_MAX
2227 * buffer, that's a waste, so do a probe + allocate. To
2228 * avoid any changes between the probe and allocate, wrap
2229 * this in inode_lock.
2232 nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
2238 struct inode *inode;
2239 struct dentry *dentry;
2241 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2245 dentry = fhp->fh_dentry;
2246 inode = d_inode(dentry);
2249 inode_lock_shared(inode);
2251 len = vfs_listxattr(dentry, NULL, 0);
2253 err = nfsd_xattr_errno(len);
2257 if (len > XATTR_LIST_MAX) {
2258 err = nfserr_xattr2big;
2263 * We're holding i_rwsem - use GFP_NOFS.
2265 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2267 err = nfserr_jukebox;
2271 len = vfs_listxattr(dentry, buf, len);
2274 err = nfsd_xattr_errno(len);
2283 inode_unlock_shared(inode);
2289 * Removexattr and setxattr need to call fh_lock to both lock the inode
2290 * and set the change attribute. Since the top-level vfs_removexattr
2291 * and vfs_setxattr calls already do their own inode_lock calls, call
2292 * the _locked variant. Pass in a NULL pointer for delegated_inode,
2293 * and let the client deal with NFS4ERR_DELAY (same as with e.g.
2294 * setattr and remove).
2297 nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
2302 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2306 ret = fh_want_write(fhp);
2308 return nfserrno(ret);
2312 ret = __vfs_removexattr_locked(&init_user_ns, fhp->fh_dentry,
2318 return nfsd_xattr_errno(ret);
2322 nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2323 void *buf, u32 len, u32 flags)
2328 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2332 ret = fh_want_write(fhp);
2334 return nfserrno(ret);
2337 ret = __vfs_setxattr_locked(&init_user_ns, fhp->fh_dentry, name, buf,
2343 return nfsd_xattr_errno(ret);
2348 * Check for a user's access permissions to this inode.
2351 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2352 struct dentry *dentry, int acc)
2354 struct inode *inode = d_inode(dentry);
2357 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
2360 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2362 (acc & NFSD_MAY_READ)? " read" : "",
2363 (acc & NFSD_MAY_WRITE)? " write" : "",
2364 (acc & NFSD_MAY_EXEC)? " exec" : "",
2365 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2366 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2367 (acc & NFSD_MAY_LOCK)? " lock" : "",
2368 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2370 IS_IMMUTABLE(inode)? " immut" : "",
2371 IS_APPEND(inode)? " append" : "",
2372 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2373 dprintk(" owner %d/%d user %d/%d\n",
2374 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2377 /* Normally we reject any write/sattr etc access on a read-only file
2378 * system. But if it is IRIX doing check on write-access for a
2379 * device special file, we ignore rofs.
2381 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2382 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2383 if (exp_rdonly(rqstp, exp) ||
2384 __mnt_is_readonly(exp->ex_path.mnt))
2386 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2389 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2392 if (acc & NFSD_MAY_LOCK) {
2393 /* If we cannot rely on authentication in NLM requests,
2394 * just allow locks, otherwise require read permission, or
2397 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2400 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2403 * The file owner always gets access permission for accesses that
2404 * would normally be checked at open time. This is to make
2405 * file access work even when the client has done a fchmod(fd, 0).
2407 * However, `cp foo bar' should fail nevertheless when bar is
2408 * readonly. A sensible way to do this might be to reject all
2409 * attempts to truncate a read-only file, because a creat() call
2410 * always implies file truncation.
2411 * ... but this isn't really fair. A process may reasonably call
2412 * ftruncate on an open file descriptor on a file with perm 000.
2413 * We must trust the client to do permission checking - using "ACCESS"
2416 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2417 uid_eq(inode->i_uid, current_fsuid()))
2420 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2421 err = inode_permission(&init_user_ns, inode,
2422 acc & (MAY_READ | MAY_WRITE | MAY_EXEC));
2424 /* Allow read access to binaries even when mode 111 */
2425 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2426 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2427 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2428 err = inode_permission(&init_user_ns, inode, MAY_EXEC);
2430 return err? nfserrno(err) : 0;