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(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(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(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0)
506 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
507 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
508 struct xdr_netobj *label)
512 struct dentry *dentry;
514 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
518 dentry = fhp->fh_dentry;
520 inode_lock(d_inode(dentry));
521 host_error = security_inode_setsecctx(dentry, label->data, label->len);
522 inode_unlock(d_inode(dentry));
523 return nfserrno(host_error);
526 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
527 struct xdr_netobj *label)
529 return nfserr_notsupp;
533 __be32 nfsd4_clone_file_range(struct nfsd_file *nf_src, u64 src_pos,
534 struct nfsd_file *nf_dst, u64 dst_pos, u64 count, bool sync)
536 struct file *src = nf_src->nf_file;
537 struct file *dst = nf_dst->nf_file;
542 since = READ_ONCE(dst->f_wb_err);
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 = filemap_check_wb_err(dst->f_mapping, since);
559 status = commit_inode_metadata(file_inode(src));
561 nfsd_reset_boot_verifier(net_generic(nf_dst->nf_net,
563 ret = nfserrno(status);
570 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
571 u64 dst_pos, u64 count)
576 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
577 * thread and client rpc slot. The choice of 4MB is somewhat
578 * arbitrary. We might instead base this on r/wsize, or make it
579 * tunable, or use a time instead of a byte limit, or implement
580 * asynchronous copy. In theory a client could also recognize a
581 * limit like this and pipeline multiple COPY requests.
583 count = min_t(u64, count, 1 << 22);
584 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
586 if (ret == -EOPNOTSUPP || ret == -EXDEV)
587 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count,
592 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
593 struct file *file, loff_t offset, loff_t len,
598 if (!S_ISREG(file_inode(file)->i_mode))
601 error = vfs_fallocate(file, flags, offset, len);
603 error = commit_metadata(fhp);
605 return nfserrno(error);
607 #endif /* defined(CONFIG_NFSD_V4) */
609 #ifdef CONFIG_NFSD_V3
611 * Check server access rights to a file system object
617 static struct accessmap nfs3_regaccess[] = {
618 { NFS3_ACCESS_READ, NFSD_MAY_READ },
619 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
620 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
621 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
623 #ifdef CONFIG_NFSD_V4
624 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
625 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
626 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
632 static struct accessmap nfs3_diraccess[] = {
633 { NFS3_ACCESS_READ, NFSD_MAY_READ },
634 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
635 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
636 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
637 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
639 #ifdef CONFIG_NFSD_V4
640 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
641 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
642 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
648 static struct accessmap nfs3_anyaccess[] = {
649 /* Some clients - Solaris 2.6 at least, make an access call
650 * to the server to check for access for things like /dev/null
651 * (which really, the server doesn't care about). So
652 * We provide simple access checking for them, looking
653 * mainly at mode bits, and we make sure to ignore read-only
656 { NFS3_ACCESS_READ, NFSD_MAY_READ },
657 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
658 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
659 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
665 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
667 struct accessmap *map;
668 struct svc_export *export;
669 struct dentry *dentry;
670 u32 query, result = 0, sresult = 0;
673 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
677 export = fhp->fh_export;
678 dentry = fhp->fh_dentry;
680 if (d_is_reg(dentry))
681 map = nfs3_regaccess;
682 else if (d_is_dir(dentry))
683 map = nfs3_diraccess;
685 map = nfs3_anyaccess;
689 for (; map->access; map++) {
690 if (map->access & query) {
693 sresult |= map->access;
695 err2 = nfsd_permission(rqstp, export, dentry, map->how);
698 result |= map->access;
701 /* the following error codes just mean the access was not allowed,
702 * rather than an error occurred */
706 /* simply don't "or" in the access bit. */
716 *supported = sresult;
721 #endif /* CONFIG_NFSD_V3 */
723 int nfsd_open_break_lease(struct inode *inode, int access)
727 if (access & NFSD_MAY_NOT_BREAK_LEASE)
729 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
730 return break_lease(inode, mode | O_NONBLOCK);
734 * Open an existing file or directory.
735 * The may_flags argument indicates the type of open (read/write/lock)
736 * and additional flags.
737 * N.B. After this call fhp needs an fh_put
740 __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
741 int may_flags, struct file **filp)
746 int flags = O_RDONLY|O_LARGEFILE;
750 path.mnt = fhp->fh_export->ex_path.mnt;
751 path.dentry = fhp->fh_dentry;
752 inode = d_inode(path.dentry);
754 /* Disallow write access to files with the append-only bit set
755 * or any access when mandatory locking enabled
758 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
761 * We must ignore files (but only files) which might have mandatory
762 * locks on them because there is no way to know if the accesser has
765 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
771 host_err = nfsd_open_break_lease(inode, may_flags);
772 if (host_err) /* NOMEM or WOULDBLOCK */
775 if (may_flags & NFSD_MAY_WRITE) {
776 if (may_flags & NFSD_MAY_READ)
777 flags = O_RDWR|O_LARGEFILE;
779 flags = O_WRONLY|O_LARGEFILE;
782 file = dentry_open(&path, flags, current_cred());
784 host_err = PTR_ERR(file);
788 host_err = ima_file_check(file, may_flags);
794 if (may_flags & NFSD_MAY_64BIT_COOKIE)
795 file->f_mode |= FMODE_64BITHASH;
797 file->f_mode |= FMODE_32BITHASH;
801 err = nfserrno(host_err);
807 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
808 int may_flags, struct file **filp)
812 validate_process_creds();
814 * If we get here, then the client has already done an "open",
815 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
816 * in case a chmod has now revoked permission.
818 * Arguably we should also allow the owner override for
819 * directories, but we never have and it doesn't seem to have
820 * caused anyone a problem. If we were to change this, note
821 * also that our filldir callbacks would need a variant of
822 * lookup_one_len that doesn't check permissions.
825 may_flags |= NFSD_MAY_OWNER_OVERRIDE;
826 err = fh_verify(rqstp, fhp, type, may_flags);
828 err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
829 validate_process_creds();
834 nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
835 int may_flags, struct file **filp)
839 validate_process_creds();
840 err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
841 validate_process_creds();
846 * Grab and keep cached pages associated with a file in the svc_rqst
847 * so that they can be passed to the network sendmsg/sendpage routines
848 * directly. They will be released after the sending has completed.
851 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
852 struct splice_desc *sd)
854 struct svc_rqst *rqstp = sd->u.data;
855 struct page **pp = rqstp->rq_next_page;
856 struct page *page = buf->page;
861 if (rqstp->rq_res.page_len == 0) {
863 put_page(*rqstp->rq_next_page);
864 *(rqstp->rq_next_page++) = page;
865 rqstp->rq_res.page_base = buf->offset;
866 rqstp->rq_res.page_len = size;
867 } else if (page != pp[-1]) {
869 if (*rqstp->rq_next_page)
870 put_page(*rqstp->rq_next_page);
871 *(rqstp->rq_next_page++) = page;
872 rqstp->rq_res.page_len += size;
874 rqstp->rq_res.page_len += size;
879 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
880 struct splice_desc *sd)
882 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
885 static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
888 if (expected != 0 && len == 0)
890 if (offset+len >= i_size_read(file_inode(file)))
895 static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
896 struct file *file, loff_t offset,
897 unsigned long *count, u32 *eof, ssize_t host_err)
900 nfsdstats.io_read += host_err;
901 *eof = nfsd_eof_on_read(file, offset, host_err, *count);
903 fsnotify_access(file);
904 trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
907 trace_nfsd_read_err(rqstp, fhp, offset, host_err);
908 return nfserrno(host_err);
912 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
913 struct file *file, loff_t offset, unsigned long *count,
916 struct splice_desc sd = {
924 trace_nfsd_read_splice(rqstp, fhp, offset, *count);
925 rqstp->rq_next_page = rqstp->rq_respages + 1;
926 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
927 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
930 __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
931 struct file *file, loff_t offset,
932 struct kvec *vec, int vlen, unsigned long *count,
935 struct iov_iter iter;
936 loff_t ppos = offset;
939 trace_nfsd_read_vector(rqstp, fhp, offset, *count);
940 iov_iter_kvec(&iter, READ, vec, vlen, *count);
941 host_err = vfs_iter_read(file, &iter, &ppos, 0);
942 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
946 * Gathered writes: If another process is currently writing to the file,
947 * there's a high chance this is another nfsd (triggered by a bulk write
948 * from a client's biod). Rather than syncing the file with each write
949 * request, we sleep for 10 msec.
951 * I don't know if this roughly approximates C. Juszak's idea of
952 * gathered writes, but it's a nice and simple solution (IMHO), and it
955 * Note: we do this only in the NFSv2 case, since v3 and higher have a
956 * better tool (separate unstable writes and commits) for solving this
959 static int wait_for_concurrent_writes(struct file *file)
961 struct inode *inode = file_inode(file);
962 static ino_t last_ino;
963 static dev_t last_dev;
966 if (atomic_read(&inode->i_writecount) > 1
967 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
968 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
970 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
973 if (inode->i_state & I_DIRTY) {
974 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
975 err = vfs_fsync(file, 0);
977 last_ino = inode->i_ino;
978 last_dev = inode->i_sb->s_dev;
983 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
984 loff_t offset, struct kvec *vec, int vlen,
985 unsigned long *cnt, int stable,
988 struct file *file = nf->nf_file;
989 struct svc_export *exp;
990 struct iov_iter iter;
996 unsigned int pflags = current->flags;
999 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
1001 if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
1003 * We want throttling in balance_dirty_pages()
1004 * and shrink_inactive_list() to only consider
1005 * the backingdev we are writing to, so that nfs to
1006 * localhost doesn't cause nfsd to lock up due to all
1007 * the client's dirty pages or its congested queue.
1009 current->flags |= PF_LOCAL_THROTTLE;
1011 exp = fhp->fh_export;
1012 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
1014 if (!EX_ISSYNC(exp))
1015 stable = NFS_UNSTABLE;
1017 if (stable && !use_wgather)
1020 iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);
1021 since = READ_ONCE(file->f_wb_err);
1022 if (flags & RWF_SYNC) {
1024 nfsd_copy_boot_verifier(verf,
1025 net_generic(SVC_NET(rqstp),
1027 host_err = vfs_iter_write(file, &iter, &pos, flags);
1029 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
1033 nfsd_copy_boot_verifier(verf,
1034 net_generic(SVC_NET(rqstp),
1036 host_err = vfs_iter_write(file, &iter, &pos, flags);
1039 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
1044 nfsdstats.io_write += *cnt;
1045 fsnotify_modify(file);
1046 host_err = filemap_check_wb_err(file->f_mapping, since);
1050 if (stable && use_wgather) {
1051 host_err = wait_for_concurrent_writes(file);
1053 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp),
1058 if (host_err >= 0) {
1059 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
1062 trace_nfsd_write_err(rqstp, fhp, offset, host_err);
1063 nfserr = nfserrno(host_err);
1065 if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
1066 current_restore_flags(pflags, PF_LOCAL_THROTTLE);
1071 * Read data from a file. count must contain the requested read count
1072 * on entry. On return, *count contains the number of bytes actually read.
1073 * N.B. After this call fhp needs an fh_put
1075 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1076 loff_t offset, struct kvec *vec, int vlen, unsigned long *count,
1079 struct nfsd_file *nf;
1083 trace_nfsd_read_start(rqstp, fhp, offset, *count);
1084 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
1089 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
1090 err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
1092 err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count, eof);
1096 trace_nfsd_read_done(rqstp, fhp, offset, *count);
1102 * Write data to a file.
1103 * The stable flag requests synchronous writes.
1104 * N.B. After this call fhp needs an fh_put
1107 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
1108 struct kvec *vec, int vlen, unsigned long *cnt, int stable,
1111 struct nfsd_file *nf;
1114 trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
1116 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_WRITE, &nf);
1120 err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,
1121 vlen, cnt, stable, verf);
1124 trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
1128 #ifdef CONFIG_NFSD_V3
1130 * Commit all pending writes to stable storage.
1132 * Note: we only guarantee that data that lies within the range specified
1133 * by the 'offset' and 'count' parameters will be synced.
1135 * Unfortunately we cannot lock the file to make sure we return full WCC
1136 * data to the client, as locking happens lower down in the filesystem.
1139 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1140 loff_t offset, unsigned long count, __be32 *verf)
1142 struct nfsd_file *nf;
1143 loff_t end = LLONG_MAX;
1144 __be32 err = nfserr_inval;
1149 end = offset + (loff_t)count - 1;
1154 err = nfsd_file_acquire(rqstp, fhp,
1155 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &nf);
1158 if (EX_ISSYNC(fhp->fh_export)) {
1159 errseq_t since = READ_ONCE(nf->nf_file->f_wb_err);
1162 err2 = vfs_fsync_range(nf->nf_file, offset, end, 0);
1165 nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net,
1167 err2 = filemap_check_wb_err(nf->nf_file->f_mapping,
1169 err = nfserrno(err2);
1172 err = nfserr_notsupp;
1175 nfsd_reset_boot_verifier(net_generic(nf->nf_net,
1177 err = nfserrno(err2);
1180 nfsd_copy_boot_verifier(verf, net_generic(nf->nf_net,
1187 #endif /* CONFIG_NFSD_V3 */
1190 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1194 * Mode has already been set earlier in create:
1196 iap->ia_valid &= ~ATTR_MODE;
1198 * Setting uid/gid works only for root. Irix appears to
1199 * send along the gid on create when it tries to implement
1200 * setgid directories via NFS:
1202 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1203 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1205 return nfsd_setattr(rqstp, resfhp, iap, 0, (time64_t)0);
1206 /* Callers expect file metadata to be committed here */
1207 return nfserrno(commit_metadata(resfhp));
1210 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1211 * setting size to 0 may fail for some specific file systems by the permission
1212 * checking which requires WRITE permission but the mode is 000.
1213 * we ignore the resizing(to 0) on the just new created file, since the size is
1214 * 0 after file created.
1216 * call this only after vfs_create() is called.
1219 nfsd_check_ignore_resizing(struct iattr *iap)
1221 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1222 iap->ia_valid &= ~ATTR_SIZE;
1225 /* The parent directory should already be locked: */
1227 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
1228 char *fname, int flen, struct iattr *iap,
1229 int type, dev_t rdev, struct svc_fh *resfhp)
1231 struct dentry *dentry, *dchild;
1237 dentry = fhp->fh_dentry;
1238 dirp = d_inode(dentry);
1240 dchild = dget(resfhp->fh_dentry);
1241 if (!fhp->fh_locked) {
1242 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
1248 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
1252 if (!(iap->ia_valid & ATTR_MODE))
1254 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1256 if (!IS_POSIXACL(dirp))
1257 iap->ia_mode &= ~current_umask();
1263 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1265 nfsd_check_ignore_resizing(iap);
1268 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1269 if (!host_err && unlikely(d_unhashed(dchild))) {
1271 d = lookup_one_len(dchild->d_name.name,
1273 dchild->d_name.len);
1275 host_err = PTR_ERR(d);
1278 if (unlikely(d_is_negative(d))) {
1280 err = nfserr_serverfault;
1283 dput(resfhp->fh_dentry);
1284 resfhp->fh_dentry = dget(d);
1285 err = fh_update(resfhp);
1296 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1299 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1306 err = nfsd_create_setattr(rqstp, resfhp, iap);
1309 * nfsd_create_setattr already committed the child. Transactional
1310 * filesystems had a chance to commit changes for both parent and
1311 * child simultaneously making the following commit_metadata a
1314 err2 = nfserrno(commit_metadata(fhp));
1318 * Update the file handle to get the new inode info.
1321 err = fh_update(resfhp);
1327 err = nfserrno(host_err);
1332 * Create a filesystem object (regular, directory, special).
1333 * Note that the parent directory is left locked.
1335 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1338 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1339 char *fname, int flen, struct iattr *iap,
1340 int type, dev_t rdev, struct svc_fh *resfhp)
1342 struct dentry *dentry, *dchild = NULL;
1346 if (isdotent(fname, flen))
1347 return nfserr_exist;
1349 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
1353 dentry = fhp->fh_dentry;
1355 host_err = fh_want_write(fhp);
1357 return nfserrno(host_err);
1359 fh_lock_nested(fhp, I_MUTEX_PARENT);
1360 dchild = lookup_one_len(fname, dentry, flen);
1361 host_err = PTR_ERR(dchild);
1363 return nfserrno(host_err);
1364 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1366 * We unconditionally drop our ref to dchild as fh_compose will have
1367 * already grabbed its own ref for it.
1372 return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
1376 #ifdef CONFIG_NFSD_V3
1379 * NFSv3 and NFSv4 version of nfsd_create
1382 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1383 char *fname, int flen, struct iattr *iap,
1384 struct svc_fh *resfhp, int createmode, u32 *verifier,
1385 bool *truncp, bool *created)
1387 struct dentry *dentry, *dchild = NULL;
1391 __u32 v_mtime=0, v_atime=0;
1397 if (isdotent(fname, flen))
1399 if (!(iap->ia_valid & ATTR_MODE))
1401 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
1405 dentry = fhp->fh_dentry;
1406 dirp = d_inode(dentry);
1408 host_err = fh_want_write(fhp);
1412 fh_lock_nested(fhp, I_MUTEX_PARENT);
1415 * Compose the response file handle.
1417 dchild = lookup_one_len(fname, dentry, flen);
1418 host_err = PTR_ERR(dchild);
1422 /* If file doesn't exist, check for permissions to create one */
1423 if (d_really_is_negative(dchild)) {
1424 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1429 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1433 if (nfsd_create_is_exclusive(createmode)) {
1434 /* solaris7 gets confused (bugid 4218508) if these have
1435 * the high bit set, so just clear the high bits. If this is
1436 * ever changed to use different attrs for storing the
1437 * verifier, then do_open_lookup() will also need to be fixed
1440 v_mtime = verifier[0]&0x7fffffff;
1441 v_atime = verifier[1]&0x7fffffff;
1444 if (d_really_is_positive(dchild)) {
1447 switch (createmode) {
1448 case NFS3_CREATE_UNCHECKED:
1449 if (! d_is_reg(dchild))
1452 /* in nfsv4, we need to treat this case a little
1453 * differently. we don't want to truncate the
1454 * file now; this would be wrong if the OPEN
1455 * fails for some other reason. furthermore,
1456 * if the size is nonzero, we should ignore it
1457 * according to spec!
1459 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1462 iap->ia_valid &= ATTR_SIZE;
1466 case NFS3_CREATE_EXCLUSIVE:
1467 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1468 && d_inode(dchild)->i_atime.tv_sec == v_atime
1469 && d_inode(dchild)->i_size == 0 ) {
1475 case NFS4_CREATE_EXCLUSIVE4_1:
1476 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1477 && d_inode(dchild)->i_atime.tv_sec == v_atime
1478 && d_inode(dchild)->i_size == 0 ) {
1484 case NFS3_CREATE_GUARDED:
1491 if (!IS_POSIXACL(dirp))
1492 iap->ia_mode &= ~current_umask();
1494 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1502 nfsd_check_ignore_resizing(iap);
1504 if (nfsd_create_is_exclusive(createmode)) {
1505 /* Cram the verifier into atime/mtime */
1506 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1507 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1508 /* XXX someone who knows this better please fix it for nsec */
1509 iap->ia_mtime.tv_sec = v_mtime;
1510 iap->ia_atime.tv_sec = v_atime;
1511 iap->ia_mtime.tv_nsec = 0;
1512 iap->ia_atime.tv_nsec = 0;
1516 err = nfsd_create_setattr(rqstp, resfhp, iap);
1519 * nfsd_create_setattr already committed the child
1520 * (and possibly also the parent).
1523 err = nfserrno(commit_metadata(fhp));
1526 * Update the filehandle to get the new inode info.
1529 err = fh_update(resfhp);
1533 if (dchild && !IS_ERR(dchild))
1539 err = nfserrno(host_err);
1542 #endif /* CONFIG_NFSD_V3 */
1545 * Read a symlink. On entry, *lenp must contain the maximum path length that
1546 * fits into the buffer. On return, it contains the true length.
1547 * N.B. After this call fhp needs an fh_put
1550 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1555 DEFINE_DELAYED_CALL(done);
1558 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1562 path.mnt = fhp->fh_export->ex_path.mnt;
1563 path.dentry = fhp->fh_dentry;
1565 if (unlikely(!d_is_symlink(path.dentry)))
1566 return nfserr_inval;
1570 link = vfs_get_link(path.dentry, &done);
1572 return nfserrno(PTR_ERR(link));
1577 memcpy(buf, link, *lenp);
1578 do_delayed_call(&done);
1583 * Create a symlink and look up its inode
1584 * N.B. After this call _both_ fhp and resfhp need an fh_put
1587 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1588 char *fname, int flen,
1590 struct svc_fh *resfhp)
1592 struct dentry *dentry, *dnew;
1597 if (!flen || path[0] == '\0')
1600 if (isdotent(fname, flen))
1603 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1607 host_err = fh_want_write(fhp);
1612 dentry = fhp->fh_dentry;
1613 dnew = lookup_one_len(fname, dentry, flen);
1614 host_err = PTR_ERR(dnew);
1618 host_err = vfs_symlink(d_inode(dentry), dnew, path);
1619 err = nfserrno(host_err);
1621 err = nfserrno(commit_metadata(fhp));
1626 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1628 if (err==0) err = cerr;
1633 err = nfserrno(host_err);
1639 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1642 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1643 char *name, int len, struct svc_fh *tfhp)
1645 struct dentry *ddir, *dnew, *dold;
1650 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1653 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1657 if (d_is_dir(tfhp->fh_dentry))
1663 if (isdotent(name, len))
1666 host_err = fh_want_write(tfhp);
1668 err = nfserrno(host_err);
1672 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1673 ddir = ffhp->fh_dentry;
1674 dirp = d_inode(ddir);
1676 dnew = lookup_one_len(name, ddir, len);
1677 host_err = PTR_ERR(dnew);
1681 dold = tfhp->fh_dentry;
1684 if (d_really_is_negative(dold))
1686 host_err = vfs_link(dold, dirp, dnew, NULL);
1688 err = nfserrno(commit_metadata(ffhp));
1690 err = nfserrno(commit_metadata(tfhp));
1692 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1695 err = nfserrno(host_err);
1701 fh_drop_write(tfhp);
1706 err = nfserrno(host_err);
1711 nfsd_close_cached_files(struct dentry *dentry)
1713 struct inode *inode = d_inode(dentry);
1715 if (inode && S_ISREG(inode->i_mode))
1716 nfsd_file_close_inode_sync(inode);
1720 nfsd_has_cached_files(struct dentry *dentry)
1723 struct inode *inode = d_inode(dentry);
1725 if (inode && S_ISREG(inode->i_mode))
1726 ret = nfsd_file_is_cached(inode);
1732 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1735 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1736 struct svc_fh *tfhp, char *tname, int tlen)
1738 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1739 struct inode *fdir, *tdir;
1742 bool has_cached = false;
1744 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1747 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1751 fdentry = ffhp->fh_dentry;
1752 fdir = d_inode(fdentry);
1754 tdentry = tfhp->fh_dentry;
1755 tdir = d_inode(tdentry);
1758 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1761 err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev;
1762 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1764 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
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)
1801 if (nfsd_has_cached_files(ndentry)) {
1805 host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
1807 host_err = commit_metadata(tfhp);
1809 host_err = commit_metadata(ffhp);
1817 err = nfserrno(host_err);
1819 * We cannot rely on fh_unlock on the two filehandles,
1820 * as that would do the wrong thing if the two directories
1821 * were the same, so again we do it by hand.
1824 fill_post_wcc(ffhp);
1825 fill_post_wcc(tfhp);
1827 unlock_rename(tdentry, fdentry);
1828 ffhp->fh_locked = tfhp->fh_locked = false;
1829 fh_drop_write(ffhp);
1832 * If the target dentry has cached open files, then we need to try to
1833 * close them prior to doing the rename. Flushing delayed fput
1834 * shouldn't be done with locks held however, so we delay it until this
1835 * point and then reattempt the whole shebang.
1839 nfsd_close_cached_files(ndentry);
1848 * Unlink a file or directory
1849 * N.B. After this call fhp needs an fh_put
1852 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1853 char *fname, int flen)
1855 struct dentry *dentry, *rdentry;
1861 if (!flen || isdotent(fname, flen))
1863 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1867 host_err = fh_want_write(fhp);
1871 fh_lock_nested(fhp, I_MUTEX_PARENT);
1872 dentry = fhp->fh_dentry;
1873 dirp = d_inode(dentry);
1875 rdentry = lookup_one_len(fname, dentry, flen);
1876 host_err = PTR_ERR(rdentry);
1877 if (IS_ERR(rdentry))
1878 goto out_drop_write;
1880 if (d_really_is_negative(rdentry)) {
1883 goto out_drop_write;
1887 type = d_inode(rdentry)->i_mode & S_IFMT;
1889 if (type != S_IFDIR) {
1890 nfsd_close_cached_files(rdentry);
1891 host_err = vfs_unlink(dirp, rdentry, NULL);
1893 host_err = vfs_rmdir(dirp, rdentry);
1897 host_err = commit_metadata(fhp);
1903 if (host_err == -EBUSY) {
1904 /* name is mounted-on. There is no perfect
1907 if (nfsd_v4client(rqstp))
1908 err = nfserr_file_open;
1912 err = nfserrno(host_err);
1919 * We do this buffering because we must not call back into the file
1920 * system's ->lookup() method from the filldir callback. That may well
1921 * deadlock a number of file systems.
1923 * This is based heavily on the implementation of same in XFS.
1925 struct buffered_dirent {
1929 unsigned int d_type;
1933 struct readdir_data {
1934 struct dir_context ctx;
1940 static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
1941 int namlen, loff_t offset, u64 ino,
1942 unsigned int d_type)
1944 struct readdir_data *buf =
1945 container_of(ctx, struct readdir_data, ctx);
1946 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1947 unsigned int reclen;
1949 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1950 if (buf->used + reclen > PAGE_SIZE) {
1955 de->namlen = namlen;
1956 de->offset = offset;
1958 de->d_type = d_type;
1959 memcpy(de->name, name, namlen);
1960 buf->used += reclen;
1965 static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func,
1966 struct readdir_cd *cdp, loff_t *offsetp)
1968 struct buffered_dirent *de;
1972 struct readdir_data buf = {
1973 .ctx.actor = nfsd_buffered_filldir,
1974 .dirent = (void *)__get_free_page(GFP_KERNEL)
1978 return nfserrno(-ENOMEM);
1983 unsigned int reclen;
1985 cdp->err = nfserr_eof; /* will be cleared on successful read */
1989 host_err = iterate_dir(file, &buf.ctx);
2001 de = (struct buffered_dirent *)buf.dirent;
2003 offset = de->offset;
2005 if (func(cdp, de->name, de->namlen, de->offset,
2006 de->ino, de->d_type))
2009 if (cdp->err != nfs_ok)
2012 reclen = ALIGN(sizeof(*de) + de->namlen,
2015 de = (struct buffered_dirent *)((char *)de + reclen);
2017 if (size > 0) /* We bailed out early */
2020 offset = vfs_llseek(file, 0, SEEK_CUR);
2023 free_page((unsigned long)(buf.dirent));
2026 return nfserrno(host_err);
2033 * Read entries from a directory.
2034 * The NFSv3/4 verifier we ignore for now.
2037 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
2038 struct readdir_cd *cdp, nfsd_filldir_t func)
2042 loff_t offset = *offsetp;
2043 int may_flags = NFSD_MAY_READ;
2045 /* NFSv2 only supports 32 bit cookies */
2046 if (rqstp->rq_vers > 2)
2047 may_flags |= NFSD_MAY_64BIT_COOKIE;
2049 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
2053 offset = vfs_llseek(file, offset, SEEK_SET);
2055 err = nfserrno((int)offset);
2059 err = nfsd_buffered_readdir(file, func, cdp, offsetp);
2061 if (err == nfserr_eof || err == nfserr_toosmall)
2062 err = nfs_ok; /* can still be found in ->err */
2070 * Get file system stats
2071 * N.B. After this call fhp needs an fh_put
2074 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
2078 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
2080 struct path path = {
2081 .mnt = fhp->fh_export->ex_path.mnt,
2082 .dentry = fhp->fh_dentry,
2084 if (vfs_statfs(&path, stat))
2090 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
2092 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
2095 #ifdef CONFIG_NFSD_V4
2097 * Helper function to translate error numbers. In the case of xattr operations,
2098 * some error codes need to be translated outside of the standard translations.
2100 * ENODATA needs to be translated to nfserr_noxattr.
2101 * E2BIG to nfserr_xattr2big.
2103 * Additionally, vfs_listxattr can return -ERANGE. This means that the
2104 * file has too many extended attributes to retrieve inside an
2105 * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
2106 * filesystems will allow the adding of extended attributes until they hit
2107 * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
2108 * So, at that point, the attributes are present and valid, but can't
2109 * be retrieved using listxattr, since the upper level xattr code enforces
2110 * the XATTR_LIST_MAX limit.
2112 * This bug means that we need to deal with listxattr returning -ERANGE. The
2113 * best mapping is to return TOOSMALL.
2116 nfsd_xattr_errno(int err)
2120 return nfserr_noxattr;
2122 return nfserr_xattr2big;
2124 return nfserr_toosmall;
2126 return nfserrno(err);
2130 * Retrieve the specified user extended attribute. To avoid always
2131 * having to allocate the maximum size (since we are not getting
2132 * a maximum size from the RPC), do a probe + alloc. Hold a reader
2133 * lock on i_rwsem to prevent the extended attribute from changing
2134 * size while we're doing this.
2137 nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2138 void **bufp, int *lenp)
2143 struct inode *inode;
2144 struct dentry *dentry;
2146 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2151 dentry = fhp->fh_dentry;
2152 inode = d_inode(dentry);
2154 inode_lock_shared(inode);
2156 len = vfs_getxattr(dentry, name, NULL, 0);
2159 * Zero-length attribute, just return.
2168 err = nfsd_xattr_errno(len);
2173 err = nfserr_toosmall;
2177 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2179 err = nfserr_jukebox;
2183 len = vfs_getxattr(dentry, name, buf, len);
2187 err = nfsd_xattr_errno(len);
2194 inode_unlock_shared(inode);
2200 * Retrieve the xattr names. Since we can't know how many are
2201 * user extended attributes, we must get all attributes here,
2202 * and have the XDR encode filter out the "user." ones.
2204 * While this could always just allocate an XATTR_LIST_MAX
2205 * buffer, that's a waste, so do a probe + allocate. To
2206 * avoid any changes between the probe and allocate, wrap
2207 * this in inode_lock.
2210 nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
2216 struct inode *inode;
2217 struct dentry *dentry;
2219 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2223 dentry = fhp->fh_dentry;
2224 inode = d_inode(dentry);
2227 inode_lock_shared(inode);
2229 len = vfs_listxattr(dentry, NULL, 0);
2231 err = nfsd_xattr_errno(len);
2235 if (len > XATTR_LIST_MAX) {
2236 err = nfserr_xattr2big;
2241 * We're holding i_rwsem - use GFP_NOFS.
2243 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2245 err = nfserr_jukebox;
2249 len = vfs_listxattr(dentry, buf, len);
2252 err = nfsd_xattr_errno(len);
2261 inode_unlock_shared(inode);
2267 * Removexattr and setxattr need to call fh_lock to both lock the inode
2268 * and set the change attribute. Since the top-level vfs_removexattr
2269 * and vfs_setxattr calls already do their own inode_lock calls, call
2270 * the _locked variant. Pass in a NULL pointer for delegated_inode,
2271 * and let the client deal with NFS4ERR_DELAY (same as with e.g.
2272 * setattr and remove).
2275 nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
2280 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2284 ret = fh_want_write(fhp);
2286 return nfserrno(ret);
2290 ret = __vfs_removexattr_locked(fhp->fh_dentry, name, NULL);
2295 return nfsd_xattr_errno(ret);
2299 nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2300 void *buf, u32 len, u32 flags)
2305 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2309 ret = fh_want_write(fhp);
2311 return nfserrno(ret);
2314 ret = __vfs_setxattr_locked(fhp->fh_dentry, name, buf, len, flags,
2320 return nfsd_xattr_errno(ret);
2325 * Check for a user's access permissions to this inode.
2328 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2329 struct dentry *dentry, int acc)
2331 struct inode *inode = d_inode(dentry);
2334 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
2337 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2339 (acc & NFSD_MAY_READ)? " read" : "",
2340 (acc & NFSD_MAY_WRITE)? " write" : "",
2341 (acc & NFSD_MAY_EXEC)? " exec" : "",
2342 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2343 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2344 (acc & NFSD_MAY_LOCK)? " lock" : "",
2345 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2347 IS_IMMUTABLE(inode)? " immut" : "",
2348 IS_APPEND(inode)? " append" : "",
2349 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2350 dprintk(" owner %d/%d user %d/%d\n",
2351 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2354 /* Normally we reject any write/sattr etc access on a read-only file
2355 * system. But if it is IRIX doing check on write-access for a
2356 * device special file, we ignore rofs.
2358 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2359 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2360 if (exp_rdonly(rqstp, exp) ||
2361 __mnt_is_readonly(exp->ex_path.mnt))
2363 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2366 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2369 if (acc & NFSD_MAY_LOCK) {
2370 /* If we cannot rely on authentication in NLM requests,
2371 * just allow locks, otherwise require read permission, or
2374 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2377 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2380 * The file owner always gets access permission for accesses that
2381 * would normally be checked at open time. This is to make
2382 * file access work even when the client has done a fchmod(fd, 0).
2384 * However, `cp foo bar' should fail nevertheless when bar is
2385 * readonly. A sensible way to do this might be to reject all
2386 * attempts to truncate a read-only file, because a creat() call
2387 * always implies file truncation.
2388 * ... but this isn't really fair. A process may reasonably call
2389 * ftruncate on an open file descriptor on a file with perm 000.
2390 * We must trust the client to do permission checking - using "ACCESS"
2393 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2394 uid_eq(inode->i_uid, current_fsuid()))
2397 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2398 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
2400 /* Allow read access to binaries even when mode 111 */
2401 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2402 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2403 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2404 err = inode_permission(inode, MAY_EXEC);
2406 return err? nfserrno(err) : 0;