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 */
49 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
53 * This is a cache of readahead params that help us choose the proper
54 * readahead strategy. Initially, we set all readahead parameters to 0
55 * and let the VFS handle things.
56 * If you increase the number of cached files very much, you'll need to
57 * add a hash table here.
60 struct raparms *p_next;
65 struct file_ra_state p_ra;
66 unsigned int p_hindex;
69 struct raparm_hbucket {
70 struct raparms *pb_head;
72 } ____cacheline_aligned_in_smp;
74 #define RAPARM_HASH_BITS 4
75 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS)
76 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1)
77 static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE];
80 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
82 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
83 * or nfs_ok having possibly changed *dpp and *expp
86 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
87 struct svc_export **expp)
89 struct svc_export *exp = *expp, *exp2 = NULL;
90 struct dentry *dentry = *dpp;
91 struct path path = {.mnt = mntget(exp->ex_path.mnt),
92 .dentry = dget(dentry)};
95 err = follow_down(&path);
98 if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
99 nfsd_mountpoint(dentry, exp) == 2) {
100 /* This is only a mountpoint in some other namespace */
105 exp2 = rqst_exp_get_by_name(rqstp, &path);
109 * We normally allow NFS clients to continue
110 * "underneath" a mountpoint that is not exported.
111 * The exception is V4ROOT, where no traversal is ever
112 * allowed without an explicit export of the new
115 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
120 if (nfsd_v4client(rqstp) ||
121 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
122 /* successfully crossed mount point */
124 * This is subtle: path.dentry is *not* on path.mnt
125 * at this point. The only reason we are safe is that
126 * original mnt is pinned down by exp, so we should
127 * put path *before* putting exp
130 path.dentry = dentry;
140 static void follow_to_parent(struct path *path)
144 while (path->dentry == path->mnt->mnt_root && follow_up(path))
146 dp = dget_parent(path->dentry);
151 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
153 struct svc_export *exp2;
154 struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
155 .dentry = dget(dparent)};
157 follow_to_parent(&path);
159 exp2 = rqst_exp_parent(rqstp, &path);
160 if (PTR_ERR(exp2) == -ENOENT) {
161 *dentryp = dget(dparent);
162 } else if (IS_ERR(exp2)) {
164 return PTR_ERR(exp2);
166 *dentryp = dget(path.dentry);
175 * For nfsd purposes, we treat V4ROOT exports as though there was an
176 * export at *every* directory.
178 * '1' if this dentry *must* be an export point,
179 * '2' if it might be, if there is really a mount here, and
180 * '0' if there is no chance of an export point here.
182 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
184 if (!d_inode(dentry))
186 if (exp->ex_flags & NFSEXP_V4ROOT)
188 if (nfsd4_is_junction(dentry))
190 if (d_mountpoint(dentry))
192 * Might only be a mountpoint in a different namespace,
193 * but we need to check.
200 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
201 const char *name, unsigned int len,
202 struct svc_export **exp_ret, struct dentry **dentry_ret)
204 struct svc_export *exp;
205 struct dentry *dparent;
206 struct dentry *dentry;
209 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
211 dparent = fhp->fh_dentry;
212 exp = exp_get(fhp->fh_export);
214 /* Lookup the name, but don't follow links */
215 if (isdotent(name, len)) {
217 dentry = dget(dparent);
218 else if (dparent != exp->ex_path.dentry)
219 dentry = dget_parent(dparent);
220 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
221 dentry = dget(dparent); /* .. == . just like at / */
223 /* checking mountpoint crossing is very different when stepping up */
224 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
230 * In the nfsd4_open() case, this may be held across
231 * subsequent open and delegation acquisition which may
232 * need to take the child's i_mutex:
234 fh_lock_nested(fhp, I_MUTEX_PARENT);
235 dentry = lookup_one_len(name, dparent, len);
236 host_err = PTR_ERR(dentry);
239 if (nfsd_mountpoint(dentry, exp)) {
241 * We don't need the i_mutex after all. It's
242 * still possible we could open this (regular
243 * files can be mountpoints too), but the
244 * i_mutex is just there to prevent renames of
245 * something that we might be about to delegate,
246 * and a mountpoint won't be renamed:
249 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
255 *dentry_ret = dentry;
261 return nfserrno(host_err);
265 * Look up one component of a pathname.
266 * N.B. After this call _both_ fhp and resfh need an fh_put
268 * If the lookup would cross a mountpoint, and the mounted filesystem
269 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
270 * accepted as it stands and the mounted directory is
271 * returned. Otherwise the covered directory is returned.
272 * NOTE: this mountpoint crossing is not supported properly by all
273 * clients and is explicitly disallowed for NFSv3
274 * NeilBrown <neilb@cse.unsw.edu.au>
277 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
278 unsigned int len, struct svc_fh *resfh)
280 struct svc_export *exp;
281 struct dentry *dentry;
284 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
287 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
290 err = check_nfsd_access(exp, rqstp);
294 * Note: we compose the file handle now, but as the
295 * dentry may be negative, it may need to be updated.
297 err = fh_compose(resfh, exp, dentry, fhp);
298 if (!err && d_really_is_negative(dentry))
307 * Commit metadata changes to stable storage.
310 commit_metadata(struct svc_fh *fhp)
312 struct inode *inode = d_inode(fhp->fh_dentry);
313 const struct export_operations *export_ops = inode->i_sb->s_export_op;
315 if (!EX_ISSYNC(fhp->fh_export))
318 if (export_ops->commit_metadata)
319 return export_ops->commit_metadata(inode);
320 return sync_inode_metadata(inode, 1);
324 * Go over the attributes and take care of the small differences between
325 * NFS semantics and what Linux expects.
328 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
330 /* sanitize the mode change */
331 if (iap->ia_valid & ATTR_MODE) {
332 iap->ia_mode &= S_IALLUGO;
333 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
336 /* Revoke setuid/setgid on chown */
337 if (!S_ISDIR(inode->i_mode) &&
338 ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
339 iap->ia_valid |= ATTR_KILL_PRIV;
340 if (iap->ia_valid & ATTR_MODE) {
341 /* we're setting mode too, just clear the s*id bits */
342 iap->ia_mode &= ~S_ISUID;
343 if (iap->ia_mode & S_IXGRP)
344 iap->ia_mode &= ~S_ISGID;
346 /* set ATTR_KILL_* bits and let VFS handle it */
347 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
353 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
356 struct inode *inode = d_inode(fhp->fh_dentry);
359 if (iap->ia_size < inode->i_size) {
362 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
363 NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
368 host_err = get_write_access(inode);
372 host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
374 goto out_put_write_access;
377 out_put_write_access:
378 put_write_access(inode);
380 return nfserrno(host_err);
384 * Set various file attributes. After this call fhp needs an fh_put.
387 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
388 int check_guard, time_t guardtime)
390 struct dentry *dentry;
392 int accmode = NFSD_MAY_SATTR;
396 bool get_write_count;
397 bool size_change = (iap->ia_valid & ATTR_SIZE);
399 if (iap->ia_valid & ATTR_SIZE) {
400 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
405 * If utimes(2) and friends are called with times not NULL, we should
406 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
407 * will return EACCESS, when the caller's effective UID does not match
408 * the owner of the file, and the caller is not privileged. In this
409 * situation, we should return EPERM(notify_change will return this).
411 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) {
412 accmode |= NFSD_MAY_OWNER_OVERRIDE;
413 if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET)))
414 accmode |= NFSD_MAY_WRITE;
417 /* Callers that do fh_verify should do the fh_want_write: */
418 get_write_count = !fhp->fh_dentry;
421 err = fh_verify(rqstp, fhp, ftype, accmode);
424 if (get_write_count) {
425 host_err = fh_want_write(fhp);
430 dentry = fhp->fh_dentry;
431 inode = d_inode(dentry);
433 /* Ignore any mode updates on symlinks */
434 if (S_ISLNK(inode->i_mode))
435 iap->ia_valid &= ~ATTR_MODE;
440 nfsd_sanitize_attrs(inode, iap);
442 if (check_guard && guardtime != inode->i_ctime.tv_sec)
443 return nfserr_notsync;
446 * The size case is special, it changes the file in addition to the
447 * attributes, and file systems don't expect it to be mixed with
448 * "random" attribute changes. We thus split out the size change
449 * into a separate call to ->setattr, and do the rest as a separate
453 err = nfsd_get_write_access(rqstp, fhp, iap);
461 * RFC5661, Section 18.30.4:
462 * Changing the size of a file with SETATTR indirectly
463 * changes the time_modify and change attributes.
465 * (and similar for the older RFCs)
467 struct iattr size_attr = {
468 .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
469 .ia_size = iap->ia_size,
472 host_err = notify_change(dentry, &size_attr, NULL);
475 iap->ia_valid &= ~ATTR_SIZE;
478 * Avoid the additional setattr call below if the only other
479 * attribute that the client sends is the mtime, as we update
480 * it as part of the size change above.
482 if ((iap->ia_valid & ~ATTR_MTIME) == 0)
486 iap->ia_valid |= ATTR_CTIME;
487 host_err = notify_change(dentry, iap, NULL);
492 put_write_access(inode);
495 host_err = commit_metadata(fhp);
496 return nfserrno(host_err);
499 #if defined(CONFIG_NFSD_V4)
501 * NFS junction information is stored in an extended attribute.
503 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
506 * nfsd4_is_junction - Test if an object could be an NFS junction
508 * @dentry: object to test
510 * Returns 1 if "dentry" appears to contain NFS junction information.
511 * Otherwise 0 is returned.
513 int nfsd4_is_junction(struct dentry *dentry)
515 struct inode *inode = d_inode(dentry);
519 if (inode->i_mode & S_IXUGO)
521 if (!(inode->i_mode & S_ISVTX))
523 if (vfs_getxattr(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0)
527 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
528 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
529 struct xdr_netobj *label)
533 struct dentry *dentry;
535 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
539 dentry = fhp->fh_dentry;
541 inode_lock(d_inode(dentry));
542 host_error = security_inode_setsecctx(dentry, label->data, label->len);
543 inode_unlock(d_inode(dentry));
544 return nfserrno(host_error);
547 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
548 struct xdr_netobj *label)
550 return nfserr_notsupp;
554 __be32 nfsd4_clone_file_range(struct file *src, u64 src_pos, struct file *dst,
555 u64 dst_pos, u64 count)
557 return nfserrno(vfs_clone_file_range(src, src_pos, dst, dst_pos,
561 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
562 u64 dst_pos, u64 count)
566 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
567 * thread and client rpc slot. The choice of 4MB is somewhat
568 * arbitrary. We might instead base this on r/wsize, or make it
569 * tunable, or use a time instead of a byte limit, or implement
570 * asynchronous copy. In theory a client could also recognize a
571 * limit like this and pipeline multiple COPY requests.
573 count = min_t(u64, count, 1 << 22);
574 return vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
577 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
578 struct file *file, loff_t offset, loff_t len,
583 if (!S_ISREG(file_inode(file)->i_mode))
586 error = vfs_fallocate(file, flags, offset, len);
588 error = commit_metadata(fhp);
590 return nfserrno(error);
592 #endif /* defined(CONFIG_NFSD_V4) */
594 #ifdef CONFIG_NFSD_V3
596 * Check server access rights to a file system object
602 static struct accessmap nfs3_regaccess[] = {
603 { NFS3_ACCESS_READ, NFSD_MAY_READ },
604 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
605 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
606 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
611 static struct accessmap nfs3_diraccess[] = {
612 { NFS3_ACCESS_READ, NFSD_MAY_READ },
613 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
614 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
615 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
616 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
621 static struct accessmap nfs3_anyaccess[] = {
622 /* Some clients - Solaris 2.6 at least, make an access call
623 * to the server to check for access for things like /dev/null
624 * (which really, the server doesn't care about). So
625 * We provide simple access checking for them, looking
626 * mainly at mode bits, and we make sure to ignore read-only
629 { NFS3_ACCESS_READ, NFSD_MAY_READ },
630 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
631 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
632 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
638 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
640 struct accessmap *map;
641 struct svc_export *export;
642 struct dentry *dentry;
643 u32 query, result = 0, sresult = 0;
646 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
650 export = fhp->fh_export;
651 dentry = fhp->fh_dentry;
653 if (d_is_reg(dentry))
654 map = nfs3_regaccess;
655 else if (d_is_dir(dentry))
656 map = nfs3_diraccess;
658 map = nfs3_anyaccess;
662 for (; map->access; map++) {
663 if (map->access & query) {
666 sresult |= map->access;
668 err2 = nfsd_permission(rqstp, export, dentry, map->how);
671 result |= map->access;
674 /* the following error codes just mean the access was not allowed,
675 * rather than an error occurred */
679 /* simply don't "or" in the access bit. */
689 *supported = sresult;
694 #endif /* CONFIG_NFSD_V3 */
696 static int nfsd_open_break_lease(struct inode *inode, int access)
700 if (access & NFSD_MAY_NOT_BREAK_LEASE)
702 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
703 return break_lease(inode, mode | O_NONBLOCK);
707 * Open an existing file or directory.
708 * The may_flags argument indicates the type of open (read/write/lock)
709 * and additional flags.
710 * N.B. After this call fhp needs an fh_put
713 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
714 int may_flags, struct file **filp)
719 int flags = O_RDONLY|O_LARGEFILE;
723 validate_process_creds();
726 * If we get here, then the client has already done an "open",
727 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
728 * in case a chmod has now revoked permission.
730 * Arguably we should also allow the owner override for
731 * directories, but we never have and it doesn't seem to have
732 * caused anyone a problem. If we were to change this, note
733 * also that our filldir callbacks would need a variant of
734 * lookup_one_len that doesn't check permissions.
737 may_flags |= NFSD_MAY_OWNER_OVERRIDE;
738 err = fh_verify(rqstp, fhp, type, may_flags);
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))
753 * We must ignore files (but only files) which might have mandatory
754 * locks on them because there is no way to know if the accesser has
757 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
763 host_err = nfsd_open_break_lease(inode, may_flags);
764 if (host_err) /* NOMEM or WOULDBLOCK */
767 if (may_flags & NFSD_MAY_WRITE) {
768 if (may_flags & NFSD_MAY_READ)
769 flags = O_RDWR|O_LARGEFILE;
771 flags = O_WRONLY|O_LARGEFILE;
774 file = dentry_open(&path, flags, current_cred());
776 host_err = PTR_ERR(file);
780 host_err = ima_file_check(file, may_flags);
786 if (may_flags & NFSD_MAY_64BIT_COOKIE)
787 file->f_mode |= FMODE_64BITHASH;
789 file->f_mode |= FMODE_32BITHASH;
793 err = nfserrno(host_err);
795 validate_process_creds();
800 nfsd_init_raparms(struct file *file)
802 struct inode *inode = file_inode(file);
803 dev_t dev = inode->i_sb->s_dev;
804 ino_t ino = inode->i_ino;
805 struct raparms *ra, **rap, **frap = NULL;
808 struct raparm_hbucket *rab;
810 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
811 rab = &raparm_hash[hash];
813 spin_lock(&rab->pb_lock);
814 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
815 if (ra->p_ino == ino && ra->p_dev == dev)
818 if (ra->p_count == 0)
821 depth = nfsdstats.ra_size;
823 spin_unlock(&rab->pb_lock);
833 if (rap != &rab->pb_head) {
835 ra->p_next = rab->pb_head;
839 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
840 spin_unlock(&rab->pb_lock);
843 file->f_ra = ra->p_ra;
847 void nfsd_put_raparams(struct file *file, struct raparms *ra)
849 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
851 spin_lock(&rab->pb_lock);
852 ra->p_ra = file->f_ra;
855 spin_unlock(&rab->pb_lock);
859 * Grab and keep cached pages associated with a file in the svc_rqst
860 * so that they can be passed to the network sendmsg/sendpage routines
861 * directly. They will be released after the sending has completed.
864 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
865 struct splice_desc *sd)
867 struct svc_rqst *rqstp = sd->u.data;
868 struct page **pp = rqstp->rq_next_page;
869 struct page *page = buf->page;
874 if (rqstp->rq_res.page_len == 0) {
876 put_page(*rqstp->rq_next_page);
877 *(rqstp->rq_next_page++) = page;
878 rqstp->rq_res.page_base = buf->offset;
879 rqstp->rq_res.page_len = size;
880 } else if (page != pp[-1]) {
882 if (*rqstp->rq_next_page)
883 put_page(*rqstp->rq_next_page);
884 *(rqstp->rq_next_page++) = page;
885 rqstp->rq_res.page_len += size;
887 rqstp->rq_res.page_len += size;
892 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
893 struct splice_desc *sd)
895 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
898 static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
899 struct file *file, loff_t offset,
900 unsigned long *count, int host_err)
903 nfsdstats.io_read += host_err;
905 fsnotify_access(file);
906 trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
909 trace_nfsd_read_err(rqstp, fhp, offset, host_err);
910 return nfserrno(host_err);
914 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
915 struct file *file, loff_t offset, unsigned long *count)
917 struct splice_desc sd = {
925 trace_nfsd_read_splice(rqstp, fhp, offset, *count);
926 rqstp->rq_next_page = rqstp->rq_respages + 1;
927 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
928 return nfsd_finish_read(rqstp, fhp, file, offset, count, host_err);
931 __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
932 struct file *file, loff_t offset,
933 struct kvec *vec, int vlen, unsigned long *count)
935 struct iov_iter iter;
938 trace_nfsd_read_vector(rqstp, fhp, offset, *count);
939 iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count);
940 host_err = vfs_iter_read(file, &iter, &offset, 0);
941 return nfsd_finish_read(rqstp, fhp, file, offset, count, host_err);
945 * Gathered writes: If another process is currently writing to the file,
946 * there's a high chance this is another nfsd (triggered by a bulk write
947 * from a client's biod). Rather than syncing the file with each write
948 * request, we sleep for 10 msec.
950 * I don't know if this roughly approximates C. Juszak's idea of
951 * gathered writes, but it's a nice and simple solution (IMHO), and it
954 * Note: we do this only in the NFSv2 case, since v3 and higher have a
955 * better tool (separate unstable writes and commits) for solving this
958 static int wait_for_concurrent_writes(struct file *file)
960 struct inode *inode = file_inode(file);
961 static ino_t last_ino;
962 static dev_t last_dev;
965 if (atomic_read(&inode->i_writecount) > 1
966 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
967 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
969 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
972 if (inode->i_state & I_DIRTY) {
973 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
974 err = vfs_fsync(file, 0);
976 last_ino = inode->i_ino;
977 last_dev = inode->i_sb->s_dev;
982 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
983 loff_t offset, struct kvec *vec, int vlen,
984 unsigned long *cnt, int stable)
986 struct svc_export *exp;
987 struct iov_iter iter;
992 unsigned int pflags = current->flags;
995 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
997 if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
999 * We want less throttling in balance_dirty_pages()
1000 * and shrink_inactive_list() so that nfs to
1001 * localhost doesn't cause nfsd to lock up due to all
1002 * the client's dirty pages or its congested queue.
1004 current->flags |= PF_LESS_THROTTLE;
1006 exp = fhp->fh_export;
1007 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
1009 if (!EX_ISSYNC(exp))
1010 stable = NFS_UNSTABLE;
1012 if (stable && !use_wgather)
1015 iov_iter_kvec(&iter, WRITE | ITER_KVEC, vec, vlen, *cnt);
1016 host_err = vfs_iter_write(file, &iter, &pos, flags);
1020 nfsdstats.io_write += *cnt;
1021 fsnotify_modify(file);
1023 if (stable && use_wgather)
1024 host_err = wait_for_concurrent_writes(file);
1027 if (host_err >= 0) {
1028 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
1031 trace_nfsd_write_err(rqstp, fhp, offset, host_err);
1032 nfserr = nfserrno(host_err);
1034 if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
1035 current_restore_flags(pflags, PF_LESS_THROTTLE);
1040 * Read data from a file. count must contain the requested read count
1041 * on entry. On return, *count contains the number of bytes actually read.
1042 * N.B. After this call fhp needs an fh_put
1044 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1045 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
1051 trace_nfsd_read_start(rqstp, fhp, offset, *count);
1052 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
1056 ra = nfsd_init_raparms(file);
1058 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
1059 err = nfsd_splice_read(rqstp, fhp, file, offset, count);
1061 err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count);
1064 nfsd_put_raparams(file, ra);
1067 trace_nfsd_read_done(rqstp, fhp, offset, *count);
1073 * Write data to a file.
1074 * The stable flag requests synchronous writes.
1075 * N.B. After this call fhp needs an fh_put
1078 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
1079 struct kvec *vec, int vlen, unsigned long *cnt, int stable)
1081 struct file *file = NULL;
1084 trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
1086 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1090 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, stable);
1093 trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
1097 #ifdef CONFIG_NFSD_V3
1099 * Commit all pending writes to stable storage.
1101 * Note: we only guarantee that data that lies within the range specified
1102 * by the 'offset' and 'count' parameters will be synced.
1104 * Unfortunately we cannot lock the file to make sure we return full WCC
1105 * data to the client, as locking happens lower down in the filesystem.
1108 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1109 loff_t offset, unsigned long count)
1112 loff_t end = LLONG_MAX;
1113 __be32 err = nfserr_inval;
1118 end = offset + (loff_t)count - 1;
1123 err = nfsd_open(rqstp, fhp, S_IFREG,
1124 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file);
1127 if (EX_ISSYNC(fhp->fh_export)) {
1128 int err2 = vfs_fsync_range(file, offset, end, 0);
1130 if (err2 != -EINVAL)
1131 err = nfserrno(err2);
1133 err = nfserr_notsupp;
1140 #endif /* CONFIG_NFSD_V3 */
1143 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1147 * Mode has already been set earlier in create:
1149 iap->ia_valid &= ~ATTR_MODE;
1151 * Setting uid/gid works only for root. Irix appears to
1152 * send along the gid on create when it tries to implement
1153 * setgid directories via NFS:
1155 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1156 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1158 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1159 /* Callers expect file metadata to be committed here */
1160 return nfserrno(commit_metadata(resfhp));
1163 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1164 * setting size to 0 may fail for some specific file systems by the permission
1165 * checking which requires WRITE permission but the mode is 000.
1166 * we ignore the resizing(to 0) on the just new created file, since the size is
1167 * 0 after file created.
1169 * call this only after vfs_create() is called.
1172 nfsd_check_ignore_resizing(struct iattr *iap)
1174 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1175 iap->ia_valid &= ~ATTR_SIZE;
1178 /* The parent directory should already be locked: */
1180 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
1181 char *fname, int flen, struct iattr *iap,
1182 int type, dev_t rdev, struct svc_fh *resfhp)
1184 struct dentry *dentry, *dchild;
1190 dentry = fhp->fh_dentry;
1191 dirp = d_inode(dentry);
1193 dchild = dget(resfhp->fh_dentry);
1194 if (!fhp->fh_locked) {
1195 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
1201 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
1205 if (!(iap->ia_valid & ATTR_MODE))
1207 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1209 if (!IS_POSIXACL(dirp))
1210 iap->ia_mode &= ~current_umask();
1216 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1218 nfsd_check_ignore_resizing(iap);
1221 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1222 if (!host_err && unlikely(d_unhashed(dchild))) {
1224 d = lookup_one_len(dchild->d_name.name,
1226 dchild->d_name.len);
1228 host_err = PTR_ERR(d);
1231 if (unlikely(d_is_negative(d))) {
1233 err = nfserr_serverfault;
1236 dput(resfhp->fh_dentry);
1237 resfhp->fh_dentry = dget(d);
1238 err = fh_update(resfhp);
1249 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1252 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1259 err = nfsd_create_setattr(rqstp, resfhp, iap);
1262 * nfsd_create_setattr already committed the child. Transactional
1263 * filesystems had a chance to commit changes for both parent and
1264 * child simultaneously making the following commit_metadata a
1267 err2 = nfserrno(commit_metadata(fhp));
1271 * Update the file handle to get the new inode info.
1274 err = fh_update(resfhp);
1280 err = nfserrno(host_err);
1285 * Create a filesystem object (regular, directory, special).
1286 * Note that the parent directory is left locked.
1288 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1291 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1292 char *fname, int flen, struct iattr *iap,
1293 int type, dev_t rdev, struct svc_fh *resfhp)
1295 struct dentry *dentry, *dchild = NULL;
1300 if (isdotent(fname, flen))
1301 return nfserr_exist;
1303 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
1307 dentry = fhp->fh_dentry;
1308 dirp = d_inode(dentry);
1310 host_err = fh_want_write(fhp);
1312 return nfserrno(host_err);
1314 fh_lock_nested(fhp, I_MUTEX_PARENT);
1315 dchild = lookup_one_len(fname, dentry, flen);
1316 host_err = PTR_ERR(dchild);
1318 return nfserrno(host_err);
1319 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1321 * We unconditionally drop our ref to dchild as fh_compose will have
1322 * already grabbed its own ref for it.
1327 return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
1331 #ifdef CONFIG_NFSD_V3
1334 * NFSv3 and NFSv4 version of nfsd_create
1337 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1338 char *fname, int flen, struct iattr *iap,
1339 struct svc_fh *resfhp, int createmode, u32 *verifier,
1340 bool *truncp, bool *created)
1342 struct dentry *dentry, *dchild = NULL;
1346 __u32 v_mtime=0, v_atime=0;
1352 if (isdotent(fname, flen))
1354 if (!(iap->ia_valid & ATTR_MODE))
1356 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
1360 dentry = fhp->fh_dentry;
1361 dirp = d_inode(dentry);
1363 host_err = fh_want_write(fhp);
1367 fh_lock_nested(fhp, I_MUTEX_PARENT);
1370 * Compose the response file handle.
1372 dchild = lookup_one_len(fname, dentry, flen);
1373 host_err = PTR_ERR(dchild);
1377 /* If file doesn't exist, check for permissions to create one */
1378 if (d_really_is_negative(dchild)) {
1379 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1384 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1388 if (nfsd_create_is_exclusive(createmode)) {
1389 /* solaris7 gets confused (bugid 4218508) if these have
1390 * the high bit set, so just clear the high bits. If this is
1391 * ever changed to use different attrs for storing the
1392 * verifier, then do_open_lookup() will also need to be fixed
1395 v_mtime = verifier[0]&0x7fffffff;
1396 v_atime = verifier[1]&0x7fffffff;
1399 if (d_really_is_positive(dchild)) {
1402 switch (createmode) {
1403 case NFS3_CREATE_UNCHECKED:
1404 if (! d_is_reg(dchild))
1407 /* in nfsv4, we need to treat this case a little
1408 * differently. we don't want to truncate the
1409 * file now; this would be wrong if the OPEN
1410 * fails for some other reason. furthermore,
1411 * if the size is nonzero, we should ignore it
1412 * according to spec!
1414 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1417 iap->ia_valid &= ATTR_SIZE;
1421 case NFS3_CREATE_EXCLUSIVE:
1422 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1423 && d_inode(dchild)->i_atime.tv_sec == v_atime
1424 && d_inode(dchild)->i_size == 0 ) {
1429 case NFS4_CREATE_EXCLUSIVE4_1:
1430 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1431 && d_inode(dchild)->i_atime.tv_sec == v_atime
1432 && d_inode(dchild)->i_size == 0 ) {
1438 case NFS3_CREATE_GUARDED:
1445 if (!IS_POSIXACL(dirp))
1446 iap->ia_mode &= ~current_umask();
1448 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1456 nfsd_check_ignore_resizing(iap);
1458 if (nfsd_create_is_exclusive(createmode)) {
1459 /* Cram the verifier into atime/mtime */
1460 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1461 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1462 /* XXX someone who knows this better please fix it for nsec */
1463 iap->ia_mtime.tv_sec = v_mtime;
1464 iap->ia_atime.tv_sec = v_atime;
1465 iap->ia_mtime.tv_nsec = 0;
1466 iap->ia_atime.tv_nsec = 0;
1470 err = nfsd_create_setattr(rqstp, resfhp, iap);
1473 * nfsd_create_setattr already committed the child
1474 * (and possibly also the parent).
1477 err = nfserrno(commit_metadata(fhp));
1480 * Update the filehandle to get the new inode info.
1483 err = fh_update(resfhp);
1487 if (dchild && !IS_ERR(dchild))
1493 err = nfserrno(host_err);
1496 #endif /* CONFIG_NFSD_V3 */
1499 * Read a symlink. On entry, *lenp must contain the maximum path length that
1500 * fits into the buffer. On return, it contains the true length.
1501 * N.B. After this call fhp needs an fh_put
1504 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1509 DEFINE_DELAYED_CALL(done);
1512 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1516 path.mnt = fhp->fh_export->ex_path.mnt;
1517 path.dentry = fhp->fh_dentry;
1519 if (unlikely(!d_is_symlink(path.dentry)))
1520 return nfserr_inval;
1524 link = vfs_get_link(path.dentry, &done);
1526 return nfserrno(PTR_ERR(link));
1531 memcpy(buf, link, *lenp);
1532 do_delayed_call(&done);
1537 * Create a symlink and look up its inode
1538 * N.B. After this call _both_ fhp and resfhp need an fh_put
1541 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1542 char *fname, int flen,
1544 struct svc_fh *resfhp)
1546 struct dentry *dentry, *dnew;
1551 if (!flen || path[0] == '\0')
1554 if (isdotent(fname, flen))
1557 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1561 host_err = fh_want_write(fhp);
1566 dentry = fhp->fh_dentry;
1567 dnew = lookup_one_len(fname, dentry, flen);
1568 host_err = PTR_ERR(dnew);
1572 host_err = vfs_symlink(d_inode(dentry), dnew, path);
1573 err = nfserrno(host_err);
1575 err = nfserrno(commit_metadata(fhp));
1580 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1582 if (err==0) err = cerr;
1587 err = nfserrno(host_err);
1593 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1596 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1597 char *name, int len, struct svc_fh *tfhp)
1599 struct dentry *ddir, *dnew, *dold;
1604 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1607 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1611 if (d_is_dir(tfhp->fh_dentry))
1617 if (isdotent(name, len))
1620 host_err = fh_want_write(tfhp);
1622 err = nfserrno(host_err);
1626 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1627 ddir = ffhp->fh_dentry;
1628 dirp = d_inode(ddir);
1630 dnew = lookup_one_len(name, ddir, len);
1631 host_err = PTR_ERR(dnew);
1635 dold = tfhp->fh_dentry;
1638 if (d_really_is_negative(dold))
1640 host_err = vfs_link(dold, dirp, dnew, NULL);
1642 err = nfserrno(commit_metadata(ffhp));
1644 err = nfserrno(commit_metadata(tfhp));
1646 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1649 err = nfserrno(host_err);
1655 fh_drop_write(tfhp);
1660 err = nfserrno(host_err);
1666 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1669 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1670 struct svc_fh *tfhp, char *tname, int tlen)
1672 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1673 struct inode *fdir, *tdir;
1677 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1680 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1684 fdentry = ffhp->fh_dentry;
1685 fdir = d_inode(fdentry);
1687 tdentry = tfhp->fh_dentry;
1688 tdir = d_inode(tdentry);
1691 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1694 host_err = fh_want_write(ffhp);
1696 err = nfserrno(host_err);
1700 /* cannot use fh_lock as we need deadlock protective ordering
1701 * so do it by hand */
1702 trap = lock_rename(tdentry, fdentry);
1703 ffhp->fh_locked = tfhp->fh_locked = true;
1707 odentry = lookup_one_len(fname, fdentry, flen);
1708 host_err = PTR_ERR(odentry);
1709 if (IS_ERR(odentry))
1713 if (d_really_is_negative(odentry))
1716 if (odentry == trap)
1719 ndentry = lookup_one_len(tname, tdentry, tlen);
1720 host_err = PTR_ERR(ndentry);
1721 if (IS_ERR(ndentry))
1723 host_err = -ENOTEMPTY;
1724 if (ndentry == trap)
1728 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1730 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
1733 host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
1735 host_err = commit_metadata(tfhp);
1737 host_err = commit_metadata(ffhp);
1744 err = nfserrno(host_err);
1746 * We cannot rely on fh_unlock on the two filehandles,
1747 * as that would do the wrong thing if the two directories
1748 * were the same, so again we do it by hand.
1750 fill_post_wcc(ffhp);
1751 fill_post_wcc(tfhp);
1752 unlock_rename(tdentry, fdentry);
1753 ffhp->fh_locked = tfhp->fh_locked = false;
1754 fh_drop_write(ffhp);
1761 * Unlink a file or directory
1762 * N.B. After this call fhp needs an fh_put
1765 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1766 char *fname, int flen)
1768 struct dentry *dentry, *rdentry;
1774 if (!flen || isdotent(fname, flen))
1776 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1780 host_err = fh_want_write(fhp);
1784 fh_lock_nested(fhp, I_MUTEX_PARENT);
1785 dentry = fhp->fh_dentry;
1786 dirp = d_inode(dentry);
1788 rdentry = lookup_one_len(fname, dentry, flen);
1789 host_err = PTR_ERR(rdentry);
1790 if (IS_ERR(rdentry))
1793 if (d_really_is_negative(rdentry)) {
1800 type = d_inode(rdentry)->i_mode & S_IFMT;
1802 if (type != S_IFDIR)
1803 host_err = vfs_unlink(dirp, rdentry, NULL);
1805 host_err = vfs_rmdir(dirp, rdentry);
1807 host_err = commit_metadata(fhp);
1811 err = nfserrno(host_err);
1817 * We do this buffering because we must not call back into the file
1818 * system's ->lookup() method from the filldir callback. That may well
1819 * deadlock a number of file systems.
1821 * This is based heavily on the implementation of same in XFS.
1823 struct buffered_dirent {
1827 unsigned int d_type;
1831 struct readdir_data {
1832 struct dir_context ctx;
1838 static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
1839 int namlen, loff_t offset, u64 ino,
1840 unsigned int d_type)
1842 struct readdir_data *buf =
1843 container_of(ctx, struct readdir_data, ctx);
1844 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1845 unsigned int reclen;
1847 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1848 if (buf->used + reclen > PAGE_SIZE) {
1853 de->namlen = namlen;
1854 de->offset = offset;
1856 de->d_type = d_type;
1857 memcpy(de->name, name, namlen);
1858 buf->used += reclen;
1863 static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func,
1864 struct readdir_cd *cdp, loff_t *offsetp)
1866 struct buffered_dirent *de;
1870 struct readdir_data buf = {
1871 .ctx.actor = nfsd_buffered_filldir,
1872 .dirent = (void *)__get_free_page(GFP_KERNEL)
1876 return nfserrno(-ENOMEM);
1881 unsigned int reclen;
1883 cdp->err = nfserr_eof; /* will be cleared on successful read */
1887 host_err = iterate_dir(file, &buf.ctx);
1899 de = (struct buffered_dirent *)buf.dirent;
1901 offset = de->offset;
1903 if (func(cdp, de->name, de->namlen, de->offset,
1904 de->ino, de->d_type))
1907 if (cdp->err != nfs_ok)
1910 reclen = ALIGN(sizeof(*de) + de->namlen,
1913 de = (struct buffered_dirent *)((char *)de + reclen);
1915 if (size > 0) /* We bailed out early */
1918 offset = vfs_llseek(file, 0, SEEK_CUR);
1921 free_page((unsigned long)(buf.dirent));
1924 return nfserrno(host_err);
1931 * Read entries from a directory.
1932 * The NFSv3/4 verifier we ignore for now.
1935 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1936 struct readdir_cd *cdp, nfsd_filldir_t func)
1940 loff_t offset = *offsetp;
1941 int may_flags = NFSD_MAY_READ;
1943 /* NFSv2 only supports 32 bit cookies */
1944 if (rqstp->rq_vers > 2)
1945 may_flags |= NFSD_MAY_64BIT_COOKIE;
1947 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
1951 offset = vfs_llseek(file, offset, SEEK_SET);
1953 err = nfserrno((int)offset);
1957 err = nfsd_buffered_readdir(file, func, cdp, offsetp);
1959 if (err == nfserr_eof || err == nfserr_toosmall)
1960 err = nfs_ok; /* can still be found in ->err */
1968 * Get file system stats
1969 * N.B. After this call fhp needs an fh_put
1972 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
1976 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
1978 struct path path = {
1979 .mnt = fhp->fh_export->ex_path.mnt,
1980 .dentry = fhp->fh_dentry,
1982 if (vfs_statfs(&path, stat))
1988 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
1990 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
1994 * Check for a user's access permissions to this inode.
1997 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
1998 struct dentry *dentry, int acc)
2000 struct inode *inode = d_inode(dentry);
2003 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
2006 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2008 (acc & NFSD_MAY_READ)? " read" : "",
2009 (acc & NFSD_MAY_WRITE)? " write" : "",
2010 (acc & NFSD_MAY_EXEC)? " exec" : "",
2011 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2012 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2013 (acc & NFSD_MAY_LOCK)? " lock" : "",
2014 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2016 IS_IMMUTABLE(inode)? " immut" : "",
2017 IS_APPEND(inode)? " append" : "",
2018 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2019 dprintk(" owner %d/%d user %d/%d\n",
2020 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2023 /* Normally we reject any write/sattr etc access on a read-only file
2024 * system. But if it is IRIX doing check on write-access for a
2025 * device special file, we ignore rofs.
2027 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2028 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2029 if (exp_rdonly(rqstp, exp) ||
2030 __mnt_is_readonly(exp->ex_path.mnt))
2032 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2035 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2038 if (acc & NFSD_MAY_LOCK) {
2039 /* If we cannot rely on authentication in NLM requests,
2040 * just allow locks, otherwise require read permission, or
2043 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2046 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2049 * The file owner always gets access permission for accesses that
2050 * would normally be checked at open time. This is to make
2051 * file access work even when the client has done a fchmod(fd, 0).
2053 * However, `cp foo bar' should fail nevertheless when bar is
2054 * readonly. A sensible way to do this might be to reject all
2055 * attempts to truncate a read-only file, because a creat() call
2056 * always implies file truncation.
2057 * ... but this isn't really fair. A process may reasonably call
2058 * ftruncate on an open file descriptor on a file with perm 000.
2059 * We must trust the client to do permission checking - using "ACCESS"
2062 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2063 uid_eq(inode->i_uid, current_fsuid()))
2066 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2067 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
2069 /* Allow read access to binaries even when mode 111 */
2070 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2071 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2072 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2073 err = inode_permission(inode, MAY_EXEC);
2075 return err? nfserrno(err) : 0;
2079 nfsd_racache_shutdown(void)
2081 struct raparms *raparm, *last_raparm;
2084 dprintk("nfsd: freeing readahead buffers.\n");
2086 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2087 raparm = raparm_hash[i].pb_head;
2089 last_raparm = raparm;
2090 raparm = raparm->p_next;
2093 raparm_hash[i].pb_head = NULL;
2097 * Initialize readahead param cache
2100 nfsd_racache_init(int cache_size)
2105 struct raparms **raparm = NULL;
2108 if (raparm_hash[0].pb_head)
2110 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
2111 nperbucket = max(2, nperbucket);
2112 cache_size = nperbucket * RAPARM_HASH_SIZE;
2114 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
2116 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2117 spin_lock_init(&raparm_hash[i].pb_lock);
2119 raparm = &raparm_hash[i].pb_head;
2120 for (j = 0; j < nperbucket; j++) {
2121 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
2124 raparm = &(*raparm)->p_next;
2129 nfsdstats.ra_size = cache_size;
2133 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2134 nfsd_racache_shutdown();