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_ATIME | ATTR_MTIME | ATTR_SIZE))
400 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
401 if (iap->ia_valid & ATTR_SIZE)
404 /* Callers that do fh_verify should do the fh_want_write: */
405 get_write_count = !fhp->fh_dentry;
408 err = fh_verify(rqstp, fhp, ftype, accmode);
411 if (get_write_count) {
412 host_err = fh_want_write(fhp);
417 dentry = fhp->fh_dentry;
418 inode = d_inode(dentry);
420 /* Ignore any mode updates on symlinks */
421 if (S_ISLNK(inode->i_mode))
422 iap->ia_valid &= ~ATTR_MODE;
427 nfsd_sanitize_attrs(inode, iap);
429 if (check_guard && guardtime != inode->i_ctime.tv_sec)
430 return nfserr_notsync;
433 * The size case is special, it changes the file in addition to the
434 * attributes, and file systems don't expect it to be mixed with
435 * "random" attribute changes. We thus split out the size change
436 * into a separate call to ->setattr, and do the rest as a separate
440 err = nfsd_get_write_access(rqstp, fhp, iap);
448 * RFC5661, Section 18.30.4:
449 * Changing the size of a file with SETATTR indirectly
450 * changes the time_modify and change attributes.
452 * (and similar for the older RFCs)
454 struct iattr size_attr = {
455 .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
456 .ia_size = iap->ia_size,
459 host_err = notify_change(dentry, &size_attr, NULL);
462 iap->ia_valid &= ~ATTR_SIZE;
465 * Avoid the additional setattr call below if the only other
466 * attribute that the client sends is the mtime, as we update
467 * it as part of the size change above.
469 if ((iap->ia_valid & ~ATTR_MTIME) == 0)
473 iap->ia_valid |= ATTR_CTIME;
474 host_err = notify_change(dentry, iap, NULL);
479 put_write_access(inode);
482 host_err = commit_metadata(fhp);
483 return nfserrno(host_err);
486 #if defined(CONFIG_NFSD_V4)
488 * NFS junction information is stored in an extended attribute.
490 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
493 * nfsd4_is_junction - Test if an object could be an NFS junction
495 * @dentry: object to test
497 * Returns 1 if "dentry" appears to contain NFS junction information.
498 * Otherwise 0 is returned.
500 int nfsd4_is_junction(struct dentry *dentry)
502 struct inode *inode = d_inode(dentry);
506 if (inode->i_mode & S_IXUGO)
508 if (!(inode->i_mode & S_ISVTX))
510 if (vfs_getxattr(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0)
514 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
515 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
516 struct xdr_netobj *label)
520 struct dentry *dentry;
522 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
526 dentry = fhp->fh_dentry;
528 inode_lock(d_inode(dentry));
529 host_error = security_inode_setsecctx(dentry, label->data, label->len);
530 inode_unlock(d_inode(dentry));
531 return nfserrno(host_error);
534 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
535 struct xdr_netobj *label)
537 return nfserr_notsupp;
541 __be32 nfsd4_clone_file_range(struct file *src, u64 src_pos, struct file *dst,
542 u64 dst_pos, u64 count)
544 return nfserrno(vfs_clone_file_range(src, src_pos, dst, dst_pos,
548 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
549 u64 dst_pos, u64 count)
553 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
554 * thread and client rpc slot. The choice of 4MB is somewhat
555 * arbitrary. We might instead base this on r/wsize, or make it
556 * tunable, or use a time instead of a byte limit, or implement
557 * asynchronous copy. In theory a client could also recognize a
558 * limit like this and pipeline multiple COPY requests.
560 count = min_t(u64, count, 1 << 22);
561 return vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
564 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
565 struct file *file, loff_t offset, loff_t len,
570 if (!S_ISREG(file_inode(file)->i_mode))
573 error = vfs_fallocate(file, flags, offset, len);
575 error = commit_metadata(fhp);
577 return nfserrno(error);
579 #endif /* defined(CONFIG_NFSD_V4) */
581 #ifdef CONFIG_NFSD_V3
583 * Check server access rights to a file system object
589 static struct accessmap nfs3_regaccess[] = {
590 { NFS3_ACCESS_READ, NFSD_MAY_READ },
591 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
592 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
593 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
598 static struct accessmap nfs3_diraccess[] = {
599 { NFS3_ACCESS_READ, NFSD_MAY_READ },
600 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
601 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
602 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
603 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
608 static struct accessmap nfs3_anyaccess[] = {
609 /* Some clients - Solaris 2.6 at least, make an access call
610 * to the server to check for access for things like /dev/null
611 * (which really, the server doesn't care about). So
612 * We provide simple access checking for them, looking
613 * mainly at mode bits, and we make sure to ignore read-only
616 { NFS3_ACCESS_READ, NFSD_MAY_READ },
617 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
618 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
619 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
625 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
627 struct accessmap *map;
628 struct svc_export *export;
629 struct dentry *dentry;
630 u32 query, result = 0, sresult = 0;
633 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
637 export = fhp->fh_export;
638 dentry = fhp->fh_dentry;
640 if (d_is_reg(dentry))
641 map = nfs3_regaccess;
642 else if (d_is_dir(dentry))
643 map = nfs3_diraccess;
645 map = nfs3_anyaccess;
649 for (; map->access; map++) {
650 if (map->access & query) {
653 sresult |= map->access;
655 err2 = nfsd_permission(rqstp, export, dentry, map->how);
658 result |= map->access;
661 /* the following error codes just mean the access was not allowed,
662 * rather than an error occurred */
666 /* simply don't "or" in the access bit. */
676 *supported = sresult;
681 #endif /* CONFIG_NFSD_V3 */
683 static int nfsd_open_break_lease(struct inode *inode, int access)
687 if (access & NFSD_MAY_NOT_BREAK_LEASE)
689 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
690 return break_lease(inode, mode | O_NONBLOCK);
694 * Open an existing file or directory.
695 * The may_flags argument indicates the type of open (read/write/lock)
696 * and additional flags.
697 * N.B. After this call fhp needs an fh_put
700 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
701 int may_flags, struct file **filp)
706 int flags = O_RDONLY|O_LARGEFILE;
710 validate_process_creds();
713 * If we get here, then the client has already done an "open",
714 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
715 * in case a chmod has now revoked permission.
717 * Arguably we should also allow the owner override for
718 * directories, but we never have and it doesn't seem to have
719 * caused anyone a problem. If we were to change this, note
720 * also that our filldir callbacks would need a variant of
721 * lookup_one_len that doesn't check permissions.
724 may_flags |= NFSD_MAY_OWNER_OVERRIDE;
725 err = fh_verify(rqstp, fhp, type, may_flags);
729 path.mnt = fhp->fh_export->ex_path.mnt;
730 path.dentry = fhp->fh_dentry;
731 inode = d_inode(path.dentry);
733 /* Disallow write access to files with the append-only bit set
734 * or any access when mandatory locking enabled
737 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
740 * We must ignore files (but only files) which might have mandatory
741 * locks on them because there is no way to know if the accesser has
744 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
750 host_err = nfsd_open_break_lease(inode, may_flags);
751 if (host_err) /* NOMEM or WOULDBLOCK */
754 if (may_flags & NFSD_MAY_WRITE) {
755 if (may_flags & NFSD_MAY_READ)
756 flags = O_RDWR|O_LARGEFILE;
758 flags = O_WRONLY|O_LARGEFILE;
761 file = dentry_open(&path, flags, current_cred());
763 host_err = PTR_ERR(file);
767 host_err = ima_file_check(file, may_flags);
773 if (may_flags & NFSD_MAY_64BIT_COOKIE)
774 file->f_mode |= FMODE_64BITHASH;
776 file->f_mode |= FMODE_32BITHASH;
780 err = nfserrno(host_err);
782 validate_process_creds();
787 nfsd_init_raparms(struct file *file)
789 struct inode *inode = file_inode(file);
790 dev_t dev = inode->i_sb->s_dev;
791 ino_t ino = inode->i_ino;
792 struct raparms *ra, **rap, **frap = NULL;
795 struct raparm_hbucket *rab;
797 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
798 rab = &raparm_hash[hash];
800 spin_lock(&rab->pb_lock);
801 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
802 if (ra->p_ino == ino && ra->p_dev == dev)
805 if (ra->p_count == 0)
808 depth = nfsdstats.ra_size;
810 spin_unlock(&rab->pb_lock);
820 if (rap != &rab->pb_head) {
822 ra->p_next = rab->pb_head;
826 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
827 spin_unlock(&rab->pb_lock);
830 file->f_ra = ra->p_ra;
834 void nfsd_put_raparams(struct file *file, struct raparms *ra)
836 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
838 spin_lock(&rab->pb_lock);
839 ra->p_ra = file->f_ra;
842 spin_unlock(&rab->pb_lock);
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 __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
886 struct file *file, loff_t offset,
887 unsigned long *count, int host_err)
890 nfsdstats.io_read += host_err;
892 fsnotify_access(file);
893 trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
896 trace_nfsd_read_err(rqstp, fhp, offset, host_err);
897 return nfserrno(host_err);
901 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
902 struct file *file, loff_t offset, unsigned long *count)
904 struct splice_desc sd = {
912 trace_nfsd_read_splice(rqstp, fhp, offset, *count);
913 rqstp->rq_next_page = rqstp->rq_respages + 1;
914 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
915 return nfsd_finish_read(rqstp, fhp, file, offset, count, host_err);
918 __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
919 struct file *file, loff_t offset,
920 struct kvec *vec, int vlen, unsigned long *count)
922 struct iov_iter iter;
925 trace_nfsd_read_vector(rqstp, fhp, offset, *count);
926 iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count);
927 host_err = vfs_iter_read(file, &iter, &offset, 0);
928 return nfsd_finish_read(rqstp, fhp, file, offset, count, host_err);
932 * Gathered writes: If another process is currently writing to the file,
933 * there's a high chance this is another nfsd (triggered by a bulk write
934 * from a client's biod). Rather than syncing the file with each write
935 * request, we sleep for 10 msec.
937 * I don't know if this roughly approximates C. Juszak's idea of
938 * gathered writes, but it's a nice and simple solution (IMHO), and it
941 * Note: we do this only in the NFSv2 case, since v3 and higher have a
942 * better tool (separate unstable writes and commits) for solving this
945 static int wait_for_concurrent_writes(struct file *file)
947 struct inode *inode = file_inode(file);
948 static ino_t last_ino;
949 static dev_t last_dev;
952 if (atomic_read(&inode->i_writecount) > 1
953 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
954 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
956 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
959 if (inode->i_state & I_DIRTY) {
960 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
961 err = vfs_fsync(file, 0);
963 last_ino = inode->i_ino;
964 last_dev = inode->i_sb->s_dev;
969 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
970 loff_t offset, struct kvec *vec, int vlen,
971 unsigned long *cnt, int stable)
973 struct svc_export *exp;
974 struct iov_iter iter;
979 unsigned int pflags = current->flags;
982 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
984 if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
986 * We want less throttling in balance_dirty_pages()
987 * and shrink_inactive_list() so that nfs to
988 * localhost doesn't cause nfsd to lock up due to all
989 * the client's dirty pages or its congested queue.
991 current->flags |= PF_LESS_THROTTLE;
993 exp = fhp->fh_export;
994 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
997 stable = NFS_UNSTABLE;
999 if (stable && !use_wgather)
1002 iov_iter_kvec(&iter, WRITE | ITER_KVEC, vec, vlen, *cnt);
1003 host_err = vfs_iter_write(file, &iter, &pos, flags);
1006 nfsdstats.io_write += *cnt;
1007 fsnotify_modify(file);
1009 if (stable && use_wgather)
1010 host_err = wait_for_concurrent_writes(file);
1013 if (host_err >= 0) {
1014 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
1017 trace_nfsd_write_err(rqstp, fhp, offset, host_err);
1018 nfserr = nfserrno(host_err);
1020 if (test_bit(RQ_LOCAL, &rqstp->rq_flags))
1021 current_restore_flags(pflags, PF_LESS_THROTTLE);
1026 * Read data from a file. count must contain the requested read count
1027 * on entry. On return, *count contains the number of bytes actually read.
1028 * N.B. After this call fhp needs an fh_put
1030 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1031 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
1037 trace_nfsd_read_start(rqstp, fhp, offset, *count);
1038 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
1042 ra = nfsd_init_raparms(file);
1044 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
1045 err = nfsd_splice_read(rqstp, fhp, file, offset, count);
1047 err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count);
1050 nfsd_put_raparams(file, ra);
1053 trace_nfsd_read_done(rqstp, fhp, offset, *count);
1059 * Write data to a file.
1060 * The stable flag requests synchronous writes.
1061 * N.B. After this call fhp needs an fh_put
1064 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
1065 struct kvec *vec, int vlen, unsigned long *cnt, int stable)
1067 struct file *file = NULL;
1070 trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
1072 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1076 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, stable);
1079 trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
1083 #ifdef CONFIG_NFSD_V3
1085 * Commit all pending writes to stable storage.
1087 * Note: we only guarantee that data that lies within the range specified
1088 * by the 'offset' and 'count' parameters will be synced.
1090 * Unfortunately we cannot lock the file to make sure we return full WCC
1091 * data to the client, as locking happens lower down in the filesystem.
1094 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1095 loff_t offset, unsigned long count)
1098 loff_t end = LLONG_MAX;
1099 __be32 err = nfserr_inval;
1104 end = offset + (loff_t)count - 1;
1109 err = nfsd_open(rqstp, fhp, S_IFREG,
1110 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file);
1113 if (EX_ISSYNC(fhp->fh_export)) {
1114 int err2 = vfs_fsync_range(file, offset, end, 0);
1116 if (err2 != -EINVAL)
1117 err = nfserrno(err2);
1119 err = nfserr_notsupp;
1126 #endif /* CONFIG_NFSD_V3 */
1129 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1133 * Mode has already been set earlier in create:
1135 iap->ia_valid &= ~ATTR_MODE;
1137 * Setting uid/gid works only for root. Irix appears to
1138 * send along the gid on create when it tries to implement
1139 * setgid directories via NFS:
1141 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1142 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1144 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1145 /* Callers expect file metadata to be committed here */
1146 return nfserrno(commit_metadata(resfhp));
1149 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1150 * setting size to 0 may fail for some specific file systems by the permission
1151 * checking which requires WRITE permission but the mode is 000.
1152 * we ignore the resizing(to 0) on the just new created file, since the size is
1153 * 0 after file created.
1155 * call this only after vfs_create() is called.
1158 nfsd_check_ignore_resizing(struct iattr *iap)
1160 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1161 iap->ia_valid &= ~ATTR_SIZE;
1164 /* The parent directory should already be locked: */
1166 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
1167 char *fname, int flen, struct iattr *iap,
1168 int type, dev_t rdev, struct svc_fh *resfhp)
1170 struct dentry *dentry, *dchild;
1176 dentry = fhp->fh_dentry;
1177 dirp = d_inode(dentry);
1179 dchild = dget(resfhp->fh_dentry);
1180 if (!fhp->fh_locked) {
1181 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
1187 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
1191 if (!(iap->ia_valid & ATTR_MODE))
1193 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1199 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1201 nfsd_check_ignore_resizing(iap);
1204 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1205 if (!host_err && unlikely(d_unhashed(dchild))) {
1207 d = lookup_one_len(dchild->d_name.name,
1209 dchild->d_name.len);
1211 host_err = PTR_ERR(d);
1214 if (unlikely(d_is_negative(d))) {
1216 err = nfserr_serverfault;
1219 dput(resfhp->fh_dentry);
1220 resfhp->fh_dentry = dget(d);
1221 err = fh_update(resfhp);
1232 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1235 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1242 err = nfsd_create_setattr(rqstp, resfhp, iap);
1245 * nfsd_create_setattr already committed the child. Transactional
1246 * filesystems had a chance to commit changes for both parent and
1247 * child simultaneously making the following commit_metadata a
1250 err2 = nfserrno(commit_metadata(fhp));
1254 * Update the file handle to get the new inode info.
1257 err = fh_update(resfhp);
1263 err = nfserrno(host_err);
1268 * Create a filesystem object (regular, directory, special).
1269 * Note that the parent directory is left locked.
1271 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1274 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1275 char *fname, int flen, struct iattr *iap,
1276 int type, dev_t rdev, struct svc_fh *resfhp)
1278 struct dentry *dentry, *dchild = NULL;
1283 if (isdotent(fname, flen))
1284 return nfserr_exist;
1286 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
1290 dentry = fhp->fh_dentry;
1291 dirp = d_inode(dentry);
1293 host_err = fh_want_write(fhp);
1295 return nfserrno(host_err);
1297 fh_lock_nested(fhp, I_MUTEX_PARENT);
1298 dchild = lookup_one_len(fname, dentry, flen);
1299 host_err = PTR_ERR(dchild);
1301 return nfserrno(host_err);
1302 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1304 * We unconditionally drop our ref to dchild as fh_compose will have
1305 * already grabbed its own ref for it.
1310 return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type,
1314 #ifdef CONFIG_NFSD_V3
1317 * NFSv3 and NFSv4 version of nfsd_create
1320 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1321 char *fname, int flen, struct iattr *iap,
1322 struct svc_fh *resfhp, int createmode, u32 *verifier,
1323 bool *truncp, bool *created)
1325 struct dentry *dentry, *dchild = NULL;
1329 __u32 v_mtime=0, v_atime=0;
1335 if (isdotent(fname, flen))
1337 if (!(iap->ia_valid & ATTR_MODE))
1339 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
1343 dentry = fhp->fh_dentry;
1344 dirp = d_inode(dentry);
1346 host_err = fh_want_write(fhp);
1350 fh_lock_nested(fhp, I_MUTEX_PARENT);
1353 * Compose the response file handle.
1355 dchild = lookup_one_len(fname, dentry, flen);
1356 host_err = PTR_ERR(dchild);
1360 /* If file doesn't exist, check for permissions to create one */
1361 if (d_really_is_negative(dchild)) {
1362 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1367 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1371 if (nfsd_create_is_exclusive(createmode)) {
1372 /* solaris7 gets confused (bugid 4218508) if these have
1373 * the high bit set, so just clear the high bits. If this is
1374 * ever changed to use different attrs for storing the
1375 * verifier, then do_open_lookup() will also need to be fixed
1378 v_mtime = verifier[0]&0x7fffffff;
1379 v_atime = verifier[1]&0x7fffffff;
1382 if (d_really_is_positive(dchild)) {
1385 switch (createmode) {
1386 case NFS3_CREATE_UNCHECKED:
1387 if (! d_is_reg(dchild))
1390 /* in nfsv4, we need to treat this case a little
1391 * differently. we don't want to truncate the
1392 * file now; this would be wrong if the OPEN
1393 * fails for some other reason. furthermore,
1394 * if the size is nonzero, we should ignore it
1395 * according to spec!
1397 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1400 iap->ia_valid &= ATTR_SIZE;
1404 case NFS3_CREATE_EXCLUSIVE:
1405 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1406 && d_inode(dchild)->i_atime.tv_sec == v_atime
1407 && d_inode(dchild)->i_size == 0 ) {
1412 case NFS4_CREATE_EXCLUSIVE4_1:
1413 if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime
1414 && d_inode(dchild)->i_atime.tv_sec == v_atime
1415 && d_inode(dchild)->i_size == 0 ) {
1421 case NFS3_CREATE_GUARDED:
1428 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1436 nfsd_check_ignore_resizing(iap);
1438 if (nfsd_create_is_exclusive(createmode)) {
1439 /* Cram the verifier into atime/mtime */
1440 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1441 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1442 /* XXX someone who knows this better please fix it for nsec */
1443 iap->ia_mtime.tv_sec = v_mtime;
1444 iap->ia_atime.tv_sec = v_atime;
1445 iap->ia_mtime.tv_nsec = 0;
1446 iap->ia_atime.tv_nsec = 0;
1450 err = nfsd_create_setattr(rqstp, resfhp, iap);
1453 * nfsd_create_setattr already committed the child
1454 * (and possibly also the parent).
1457 err = nfserrno(commit_metadata(fhp));
1460 * Update the filehandle to get the new inode info.
1463 err = fh_update(resfhp);
1467 if (dchild && !IS_ERR(dchild))
1473 err = nfserrno(host_err);
1476 #endif /* CONFIG_NFSD_V3 */
1479 * Read a symlink. On entry, *lenp must contain the maximum path length that
1480 * fits into the buffer. On return, it contains the true length.
1481 * N.B. After this call fhp needs an fh_put
1484 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1489 DEFINE_DELAYED_CALL(done);
1492 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1496 path.mnt = fhp->fh_export->ex_path.mnt;
1497 path.dentry = fhp->fh_dentry;
1499 if (unlikely(!d_is_symlink(path.dentry)))
1500 return nfserr_inval;
1504 link = vfs_get_link(path.dentry, &done);
1506 return nfserrno(PTR_ERR(link));
1511 memcpy(buf, link, *lenp);
1512 do_delayed_call(&done);
1517 * Create a symlink and look up its inode
1518 * N.B. After this call _both_ fhp and resfhp need an fh_put
1521 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1522 char *fname, int flen,
1524 struct svc_fh *resfhp)
1526 struct dentry *dentry, *dnew;
1531 if (!flen || path[0] == '\0')
1534 if (isdotent(fname, flen))
1537 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1541 host_err = fh_want_write(fhp);
1546 dentry = fhp->fh_dentry;
1547 dnew = lookup_one_len(fname, dentry, flen);
1548 host_err = PTR_ERR(dnew);
1552 host_err = vfs_symlink(d_inode(dentry), dnew, path);
1553 err = nfserrno(host_err);
1555 err = nfserrno(commit_metadata(fhp));
1560 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1562 if (err==0) err = cerr;
1567 err = nfserrno(host_err);
1573 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1576 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1577 char *name, int len, struct svc_fh *tfhp)
1579 struct dentry *ddir, *dnew, *dold;
1584 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1587 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1591 if (d_is_dir(tfhp->fh_dentry))
1597 if (isdotent(name, len))
1600 host_err = fh_want_write(tfhp);
1602 err = nfserrno(host_err);
1606 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1607 ddir = ffhp->fh_dentry;
1608 dirp = d_inode(ddir);
1610 dnew = lookup_one_len(name, ddir, len);
1611 host_err = PTR_ERR(dnew);
1615 dold = tfhp->fh_dentry;
1618 if (d_really_is_negative(dold))
1620 host_err = vfs_link(dold, dirp, dnew, NULL);
1622 err = nfserrno(commit_metadata(ffhp));
1624 err = nfserrno(commit_metadata(tfhp));
1626 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1629 err = nfserrno(host_err);
1635 fh_drop_write(tfhp);
1640 err = nfserrno(host_err);
1646 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1649 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1650 struct svc_fh *tfhp, char *tname, int tlen)
1652 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1653 struct inode *fdir, *tdir;
1657 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1660 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1664 fdentry = ffhp->fh_dentry;
1665 fdir = d_inode(fdentry);
1667 tdentry = tfhp->fh_dentry;
1668 tdir = d_inode(tdentry);
1671 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1674 host_err = fh_want_write(ffhp);
1676 err = nfserrno(host_err);
1680 /* cannot use fh_lock as we need deadlock protective ordering
1681 * so do it by hand */
1682 trap = lock_rename(tdentry, fdentry);
1683 ffhp->fh_locked = tfhp->fh_locked = true;
1687 odentry = lookup_one_len(fname, fdentry, flen);
1688 host_err = PTR_ERR(odentry);
1689 if (IS_ERR(odentry))
1693 if (d_really_is_negative(odentry))
1696 if (odentry == trap)
1699 ndentry = lookup_one_len(tname, tdentry, tlen);
1700 host_err = PTR_ERR(ndentry);
1701 if (IS_ERR(ndentry))
1703 host_err = -ENOTEMPTY;
1704 if (ndentry == trap)
1708 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1710 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
1713 host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
1715 host_err = commit_metadata(tfhp);
1717 host_err = commit_metadata(ffhp);
1724 err = nfserrno(host_err);
1726 * We cannot rely on fh_unlock on the two filehandles,
1727 * as that would do the wrong thing if the two directories
1728 * were the same, so again we do it by hand.
1730 fill_post_wcc(ffhp);
1731 fill_post_wcc(tfhp);
1732 unlock_rename(tdentry, fdentry);
1733 ffhp->fh_locked = tfhp->fh_locked = false;
1734 fh_drop_write(ffhp);
1741 * Unlink a file or directory
1742 * N.B. After this call fhp needs an fh_put
1745 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1746 char *fname, int flen)
1748 struct dentry *dentry, *rdentry;
1754 if (!flen || isdotent(fname, flen))
1756 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1760 host_err = fh_want_write(fhp);
1764 fh_lock_nested(fhp, I_MUTEX_PARENT);
1765 dentry = fhp->fh_dentry;
1766 dirp = d_inode(dentry);
1768 rdentry = lookup_one_len(fname, dentry, flen);
1769 host_err = PTR_ERR(rdentry);
1770 if (IS_ERR(rdentry))
1773 if (d_really_is_negative(rdentry)) {
1780 type = d_inode(rdentry)->i_mode & S_IFMT;
1782 if (type != S_IFDIR)
1783 host_err = vfs_unlink(dirp, rdentry, NULL);
1785 host_err = vfs_rmdir(dirp, rdentry);
1787 host_err = commit_metadata(fhp);
1791 err = nfserrno(host_err);
1797 * We do this buffering because we must not call back into the file
1798 * system's ->lookup() method from the filldir callback. That may well
1799 * deadlock a number of file systems.
1801 * This is based heavily on the implementation of same in XFS.
1803 struct buffered_dirent {
1807 unsigned int d_type;
1811 struct readdir_data {
1812 struct dir_context ctx;
1818 static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
1819 int namlen, loff_t offset, u64 ino,
1820 unsigned int d_type)
1822 struct readdir_data *buf =
1823 container_of(ctx, struct readdir_data, ctx);
1824 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1825 unsigned int reclen;
1827 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1828 if (buf->used + reclen > PAGE_SIZE) {
1833 de->namlen = namlen;
1834 de->offset = offset;
1836 de->d_type = d_type;
1837 memcpy(de->name, name, namlen);
1838 buf->used += reclen;
1843 static __be32 nfsd_buffered_readdir(struct file *file, nfsd_filldir_t func,
1844 struct readdir_cd *cdp, loff_t *offsetp)
1846 struct buffered_dirent *de;
1850 struct readdir_data buf = {
1851 .ctx.actor = nfsd_buffered_filldir,
1852 .dirent = (void *)__get_free_page(GFP_KERNEL)
1856 return nfserrno(-ENOMEM);
1861 unsigned int reclen;
1863 cdp->err = nfserr_eof; /* will be cleared on successful read */
1867 host_err = iterate_dir(file, &buf.ctx);
1879 de = (struct buffered_dirent *)buf.dirent;
1881 offset = de->offset;
1883 if (func(cdp, de->name, de->namlen, de->offset,
1884 de->ino, de->d_type))
1887 if (cdp->err != nfs_ok)
1890 reclen = ALIGN(sizeof(*de) + de->namlen,
1893 de = (struct buffered_dirent *)((char *)de + reclen);
1895 if (size > 0) /* We bailed out early */
1898 offset = vfs_llseek(file, 0, SEEK_CUR);
1901 free_page((unsigned long)(buf.dirent));
1904 return nfserrno(host_err);
1911 * Read entries from a directory.
1912 * The NFSv3/4 verifier we ignore for now.
1915 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1916 struct readdir_cd *cdp, nfsd_filldir_t func)
1920 loff_t offset = *offsetp;
1921 int may_flags = NFSD_MAY_READ;
1923 /* NFSv2 only supports 32 bit cookies */
1924 if (rqstp->rq_vers > 2)
1925 may_flags |= NFSD_MAY_64BIT_COOKIE;
1927 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
1931 offset = vfs_llseek(file, offset, SEEK_SET);
1933 err = nfserrno((int)offset);
1937 err = nfsd_buffered_readdir(file, func, cdp, offsetp);
1939 if (err == nfserr_eof || err == nfserr_toosmall)
1940 err = nfs_ok; /* can still be found in ->err */
1948 * Get file system stats
1949 * N.B. After this call fhp needs an fh_put
1952 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
1956 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
1958 struct path path = {
1959 .mnt = fhp->fh_export->ex_path.mnt,
1960 .dentry = fhp->fh_dentry,
1962 if (vfs_statfs(&path, stat))
1968 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
1970 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
1974 * Check for a user's access permissions to this inode.
1977 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
1978 struct dentry *dentry, int acc)
1980 struct inode *inode = d_inode(dentry);
1983 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
1986 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
1988 (acc & NFSD_MAY_READ)? " read" : "",
1989 (acc & NFSD_MAY_WRITE)? " write" : "",
1990 (acc & NFSD_MAY_EXEC)? " exec" : "",
1991 (acc & NFSD_MAY_SATTR)? " sattr" : "",
1992 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
1993 (acc & NFSD_MAY_LOCK)? " lock" : "",
1994 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
1996 IS_IMMUTABLE(inode)? " immut" : "",
1997 IS_APPEND(inode)? " append" : "",
1998 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
1999 dprintk(" owner %d/%d user %d/%d\n",
2000 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2003 /* Normally we reject any write/sattr etc access on a read-only file
2004 * system. But if it is IRIX doing check on write-access for a
2005 * device special file, we ignore rofs.
2007 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2008 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2009 if (exp_rdonly(rqstp, exp) ||
2010 __mnt_is_readonly(exp->ex_path.mnt))
2012 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2015 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2018 if (acc & NFSD_MAY_LOCK) {
2019 /* If we cannot rely on authentication in NLM requests,
2020 * just allow locks, otherwise require read permission, or
2023 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2026 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2029 * The file owner always gets access permission for accesses that
2030 * would normally be checked at open time. This is to make
2031 * file access work even when the client has done a fchmod(fd, 0).
2033 * However, `cp foo bar' should fail nevertheless when bar is
2034 * readonly. A sensible way to do this might be to reject all
2035 * attempts to truncate a read-only file, because a creat() call
2036 * always implies file truncation.
2037 * ... but this isn't really fair. A process may reasonably call
2038 * ftruncate on an open file descriptor on a file with perm 000.
2039 * We must trust the client to do permission checking - using "ACCESS"
2042 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2043 uid_eq(inode->i_uid, current_fsuid()))
2046 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2047 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
2049 /* Allow read access to binaries even when mode 111 */
2050 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2051 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2052 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2053 err = inode_permission(inode, MAY_EXEC);
2055 return err? nfserrno(err) : 0;
2059 nfsd_racache_shutdown(void)
2061 struct raparms *raparm, *last_raparm;
2064 dprintk("nfsd: freeing readahead buffers.\n");
2066 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2067 raparm = raparm_hash[i].pb_head;
2069 last_raparm = raparm;
2070 raparm = raparm->p_next;
2073 raparm_hash[i].pb_head = NULL;
2077 * Initialize readahead param cache
2080 nfsd_racache_init(int cache_size)
2085 struct raparms **raparm = NULL;
2088 if (raparm_hash[0].pb_head)
2090 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
2091 nperbucket = max(2, nperbucket);
2092 cache_size = nperbucket * RAPARM_HASH_SIZE;
2094 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
2096 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2097 spin_lock_init(&raparm_hash[i].pb_lock);
2099 raparm = &raparm_hash[i].pb_head;
2100 for (j = 0; j < nperbucket; j++) {
2101 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
2104 raparm = &(*raparm)->p_next;
2109 nfsdstats.ra_size = cache_size;
2113 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2114 nfsd_racache_shutdown();