1 // SPDX-License-Identifier: GPL-2.0
3 * File operations used by nfsd. Some of these have been ripped from
4 * other parts of the kernel because they weren't exported, others
5 * are partial duplicates with added or changed functionality.
7 * Note that several functions dget() the dentry upon which they want
8 * to act, most notably those that create directory entries. Response
9 * dentry's are dput()'d if necessary in the release callback.
10 * So if you notice code paths that apparently fail to dput() the
11 * dentry, don't worry--they have been taken care of.
13 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
14 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
18 #include <linux/file.h>
19 #include <linux/splice.h>
20 #include <linux/falloc.h>
21 #include <linux/fcntl.h>
22 #include <linux/namei.h>
23 #include <linux/delay.h>
24 #include <linux/fsnotify.h>
25 #include <linux/posix_acl_xattr.h>
26 #include <linux/xattr.h>
27 #include <linux/jhash.h>
28 #include <linux/ima.h>
29 #include <linux/slab.h>
30 #include <linux/uaccess.h>
31 #include <linux/exportfs.h>
32 #include <linux/writeback.h>
33 #include <linux/security.h>
37 #endif /* CONFIG_NFSD_V3 */
40 #include "../internal.h"
43 #endif /* CONFIG_NFSD_V4 */
47 #include "filecache.h"
50 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
53 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
55 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
56 * or nfs_ok having possibly changed *dpp and *expp
59 nfsd_cross_mnt(struct svc_rqst
*rqstp
, struct dentry
**dpp
,
60 struct svc_export
**expp
)
62 struct svc_export
*exp
= *expp
, *exp2
= NULL
;
63 struct dentry
*dentry
= *dpp
;
64 struct path path
= {.mnt
= mntget(exp
->ex_path
.mnt
),
65 .dentry
= dget(dentry
)};
68 err
= follow_down(&path
);
71 if (path
.mnt
== exp
->ex_path
.mnt
&& path
.dentry
== dentry
&&
72 nfsd_mountpoint(dentry
, exp
) == 2) {
73 /* This is only a mountpoint in some other namespace */
78 exp2
= rqst_exp_get_by_name(rqstp
, &path
);
82 * We normally allow NFS clients to continue
83 * "underneath" a mountpoint that is not exported.
84 * The exception is V4ROOT, where no traversal is ever
85 * allowed without an explicit export of the new
88 if (err
== -ENOENT
&& !(exp
->ex_flags
& NFSEXP_V4ROOT
))
93 if (nfsd_v4client(rqstp
) ||
94 (exp
->ex_flags
& NFSEXP_CROSSMOUNT
) || EX_NOHIDE(exp2
)) {
95 /* successfully crossed mount point */
97 * This is subtle: path.dentry is *not* on path.mnt
98 * at this point. The only reason we are safe is that
99 * original mnt is pinned down by exp, so we should
100 * put path *before* putting exp
103 path
.dentry
= dentry
;
113 static void follow_to_parent(struct path
*path
)
117 while (path
->dentry
== path
->mnt
->mnt_root
&& follow_up(path
))
119 dp
= dget_parent(path
->dentry
);
124 static int nfsd_lookup_parent(struct svc_rqst
*rqstp
, struct dentry
*dparent
, struct svc_export
**exp
, struct dentry
**dentryp
)
126 struct svc_export
*exp2
;
127 struct path path
= {.mnt
= mntget((*exp
)->ex_path
.mnt
),
128 .dentry
= dget(dparent
)};
130 follow_to_parent(&path
);
132 exp2
= rqst_exp_parent(rqstp
, &path
);
133 if (PTR_ERR(exp2
) == -ENOENT
) {
134 *dentryp
= dget(dparent
);
135 } else if (IS_ERR(exp2
)) {
137 return PTR_ERR(exp2
);
139 *dentryp
= dget(path
.dentry
);
148 * For nfsd purposes, we treat V4ROOT exports as though there was an
149 * export at *every* directory.
151 * '1' if this dentry *must* be an export point,
152 * '2' if it might be, if there is really a mount here, and
153 * '0' if there is no chance of an export point here.
155 int nfsd_mountpoint(struct dentry
*dentry
, struct svc_export
*exp
)
157 if (!d_inode(dentry
))
159 if (exp
->ex_flags
& NFSEXP_V4ROOT
)
161 if (nfsd4_is_junction(dentry
))
163 if (d_mountpoint(dentry
))
165 * Might only be a mountpoint in a different namespace,
166 * but we need to check.
173 nfsd_lookup_dentry(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
174 const char *name
, unsigned int len
,
175 struct svc_export
**exp_ret
, struct dentry
**dentry_ret
)
177 struct svc_export
*exp
;
178 struct dentry
*dparent
;
179 struct dentry
*dentry
;
182 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp
), len
,name
);
184 dparent
= fhp
->fh_dentry
;
185 exp
= exp_get(fhp
->fh_export
);
187 /* Lookup the name, but don't follow links */
188 if (isdotent(name
, len
)) {
190 dentry
= dget(dparent
);
191 else if (dparent
!= exp
->ex_path
.dentry
)
192 dentry
= dget_parent(dparent
);
193 else if (!EX_NOHIDE(exp
) && !nfsd_v4client(rqstp
))
194 dentry
= dget(dparent
); /* .. == . just like at / */
196 /* checking mountpoint crossing is very different when stepping up */
197 host_err
= nfsd_lookup_parent(rqstp
, dparent
, &exp
, &dentry
);
203 * In the nfsd4_open() case, this may be held across
204 * subsequent open and delegation acquisition which may
205 * need to take the child's i_mutex:
207 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
208 dentry
= lookup_one_len(name
, dparent
, len
);
209 host_err
= PTR_ERR(dentry
);
212 if (nfsd_mountpoint(dentry
, exp
)) {
214 * We don't need the i_mutex after all. It's
215 * still possible we could open this (regular
216 * files can be mountpoints too), but the
217 * i_mutex is just there to prevent renames of
218 * something that we might be about to delegate,
219 * and a mountpoint won't be renamed:
222 if ((host_err
= nfsd_cross_mnt(rqstp
, &dentry
, &exp
))) {
228 *dentry_ret
= dentry
;
234 return nfserrno(host_err
);
238 * Look up one component of a pathname.
239 * N.B. After this call _both_ fhp and resfh need an fh_put
241 * If the lookup would cross a mountpoint, and the mounted filesystem
242 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
243 * accepted as it stands and the mounted directory is
244 * returned. Otherwise the covered directory is returned.
245 * NOTE: this mountpoint crossing is not supported properly by all
246 * clients and is explicitly disallowed for NFSv3
249 nfsd_lookup(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, const char *name
,
250 unsigned int len
, struct svc_fh
*resfh
)
252 struct svc_export
*exp
;
253 struct dentry
*dentry
;
256 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_EXEC
);
259 err
= nfsd_lookup_dentry(rqstp
, fhp
, name
, len
, &exp
, &dentry
);
262 err
= check_nfsd_access(exp
, rqstp
);
266 * Note: we compose the file handle now, but as the
267 * dentry may be negative, it may need to be updated.
269 err
= fh_compose(resfh
, exp
, dentry
, fhp
);
270 if (!err
&& d_really_is_negative(dentry
))
279 * Commit metadata changes to stable storage.
282 commit_inode_metadata(struct inode
*inode
)
284 const struct export_operations
*export_ops
= inode
->i_sb
->s_export_op
;
286 if (export_ops
->commit_metadata
)
287 return export_ops
->commit_metadata(inode
);
288 return sync_inode_metadata(inode
, 1);
292 commit_metadata(struct svc_fh
*fhp
)
294 struct inode
*inode
= d_inode(fhp
->fh_dentry
);
296 if (!EX_ISSYNC(fhp
->fh_export
))
298 return commit_inode_metadata(inode
);
302 * Go over the attributes and take care of the small differences between
303 * NFS semantics and what Linux expects.
306 nfsd_sanitize_attrs(struct inode
*inode
, struct iattr
*iap
)
308 /* sanitize the mode change */
309 if (iap
->ia_valid
& ATTR_MODE
) {
310 iap
->ia_mode
&= S_IALLUGO
;
311 iap
->ia_mode
|= (inode
->i_mode
& ~S_IALLUGO
);
314 /* Revoke setuid/setgid on chown */
315 if (!S_ISDIR(inode
->i_mode
) &&
316 ((iap
->ia_valid
& ATTR_UID
) || (iap
->ia_valid
& ATTR_GID
))) {
317 iap
->ia_valid
|= ATTR_KILL_PRIV
;
318 if (iap
->ia_valid
& ATTR_MODE
) {
319 /* we're setting mode too, just clear the s*id bits */
320 iap
->ia_mode
&= ~S_ISUID
;
321 if (iap
->ia_mode
& S_IXGRP
)
322 iap
->ia_mode
&= ~S_ISGID
;
324 /* set ATTR_KILL_* bits and let VFS handle it */
325 iap
->ia_valid
|= (ATTR_KILL_SUID
| ATTR_KILL_SGID
);
331 nfsd_get_write_access(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
334 struct inode
*inode
= d_inode(fhp
->fh_dentry
);
336 if (iap
->ia_size
< inode
->i_size
) {
339 err
= nfsd_permission(rqstp
, fhp
->fh_export
, fhp
->fh_dentry
,
340 NFSD_MAY_TRUNC
| NFSD_MAY_OWNER_OVERRIDE
);
344 return nfserrno(get_write_access(inode
));
348 * Set various file attributes. After this call fhp needs an fh_put.
351 nfsd_setattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct iattr
*iap
,
352 int check_guard
, time64_t guardtime
)
354 struct dentry
*dentry
;
356 int accmode
= NFSD_MAY_SATTR
;
360 bool get_write_count
;
361 bool size_change
= (iap
->ia_valid
& ATTR_SIZE
);
363 if (iap
->ia_valid
& ATTR_SIZE
) {
364 accmode
|= NFSD_MAY_WRITE
|NFSD_MAY_OWNER_OVERRIDE
;
369 * If utimes(2) and friends are called with times not NULL, we should
370 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
371 * will return EACCES, when the caller's effective UID does not match
372 * the owner of the file, and the caller is not privileged. In this
373 * situation, we should return EPERM(notify_change will return this).
375 if (iap
->ia_valid
& (ATTR_ATIME
| ATTR_MTIME
)) {
376 accmode
|= NFSD_MAY_OWNER_OVERRIDE
;
377 if (!(iap
->ia_valid
& (ATTR_ATIME_SET
| ATTR_MTIME_SET
)))
378 accmode
|= NFSD_MAY_WRITE
;
381 /* Callers that do fh_verify should do the fh_want_write: */
382 get_write_count
= !fhp
->fh_dentry
;
385 err
= fh_verify(rqstp
, fhp
, ftype
, accmode
);
388 if (get_write_count
) {
389 host_err
= fh_want_write(fhp
);
394 dentry
= fhp
->fh_dentry
;
395 inode
= d_inode(dentry
);
397 /* Ignore any mode updates on symlinks */
398 if (S_ISLNK(inode
->i_mode
))
399 iap
->ia_valid
&= ~ATTR_MODE
;
404 nfsd_sanitize_attrs(inode
, iap
);
406 if (check_guard
&& guardtime
!= inode
->i_ctime
.tv_sec
)
407 return nfserr_notsync
;
410 * The size case is special, it changes the file in addition to the
411 * attributes, and file systems don't expect it to be mixed with
412 * "random" attribute changes. We thus split out the size change
413 * into a separate call to ->setattr, and do the rest as a separate
417 err
= nfsd_get_write_access(rqstp
, fhp
, iap
);
425 * RFC5661, Section 18.30.4:
426 * Changing the size of a file with SETATTR indirectly
427 * changes the time_modify and change attributes.
429 * (and similar for the older RFCs)
431 struct iattr size_attr
= {
432 .ia_valid
= ATTR_SIZE
| ATTR_CTIME
| ATTR_MTIME
,
433 .ia_size
= iap
->ia_size
,
437 if (iap
->ia_size
< 0)
440 host_err
= notify_change(&init_user_ns
, dentry
, &size_attr
, NULL
);
443 iap
->ia_valid
&= ~ATTR_SIZE
;
446 * Avoid the additional setattr call below if the only other
447 * attribute that the client sends is the mtime, as we update
448 * it as part of the size change above.
450 if ((iap
->ia_valid
& ~ATTR_MTIME
) == 0)
454 iap
->ia_valid
|= ATTR_CTIME
;
455 host_err
= notify_change(&init_user_ns
, dentry
, iap
, NULL
);
460 put_write_access(inode
);
463 host_err
= commit_metadata(fhp
);
464 return nfserrno(host_err
);
467 #if defined(CONFIG_NFSD_V4)
469 * NFS junction information is stored in an extended attribute.
471 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
474 * nfsd4_is_junction - Test if an object could be an NFS junction
476 * @dentry: object to test
478 * Returns 1 if "dentry" appears to contain NFS junction information.
479 * Otherwise 0 is returned.
481 int nfsd4_is_junction(struct dentry
*dentry
)
483 struct inode
*inode
= d_inode(dentry
);
487 if (inode
->i_mode
& S_IXUGO
)
489 if (!(inode
->i_mode
& S_ISVTX
))
491 if (vfs_getxattr(&init_user_ns
, dentry
, NFSD_JUNCTION_XATTR_NAME
,
496 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
497 __be32
nfsd4_set_nfs4_label(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
498 struct xdr_netobj
*label
)
502 struct dentry
*dentry
;
504 error
= fh_verify(rqstp
, fhp
, 0 /* S_IFREG */, NFSD_MAY_SATTR
);
508 dentry
= fhp
->fh_dentry
;
510 inode_lock(d_inode(dentry
));
511 host_error
= security_inode_setsecctx(dentry
, label
->data
, label
->len
);
512 inode_unlock(d_inode(dentry
));
513 return nfserrno(host_error
);
516 __be32
nfsd4_set_nfs4_label(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
517 struct xdr_netobj
*label
)
519 return nfserr_notsupp
;
523 __be32
nfsd4_clone_file_range(struct nfsd_file
*nf_src
, u64 src_pos
,
524 struct nfsd_file
*nf_dst
, u64 dst_pos
, u64 count
, bool sync
)
526 struct file
*src
= nf_src
->nf_file
;
527 struct file
*dst
= nf_dst
->nf_file
;
532 since
= READ_ONCE(dst
->f_wb_err
);
533 cloned
= vfs_clone_file_range(src
, src_pos
, dst
, dst_pos
, count
, 0);
535 ret
= nfserrno(cloned
);
538 if (count
&& cloned
!= count
) {
539 ret
= nfserrno(-EINVAL
);
543 loff_t dst_end
= count
? dst_pos
+ count
- 1 : LLONG_MAX
;
544 int status
= vfs_fsync_range(dst
, dst_pos
, dst_end
, 0);
547 status
= filemap_check_wb_err(dst
->f_mapping
, since
);
549 status
= commit_inode_metadata(file_inode(src
));
551 nfsd_reset_boot_verifier(net_generic(nf_dst
->nf_net
,
553 ret
= nfserrno(status
);
560 ssize_t
nfsd_copy_file_range(struct file
*src
, u64 src_pos
, struct file
*dst
,
561 u64 dst_pos
, u64 count
)
565 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
566 * thread and client rpc slot. The choice of 4MB is somewhat
567 * arbitrary. We might instead base this on r/wsize, or make it
568 * tunable, or use a time instead of a byte limit, or implement
569 * asynchronous copy. In theory a client could also recognize a
570 * limit like this and pipeline multiple COPY requests.
572 count
= min_t(u64
, count
, 1 << 22);
573 return vfs_copy_file_range(src
, src_pos
, dst
, dst_pos
, count
, 0);
576 __be32
nfsd4_vfs_fallocate(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
577 struct file
*file
, loff_t offset
, loff_t len
,
582 if (!S_ISREG(file_inode(file
)->i_mode
))
585 error
= vfs_fallocate(file
, flags
, offset
, len
);
587 error
= commit_metadata(fhp
);
589 return nfserrno(error
);
591 #endif /* defined(CONFIG_NFSD_V4) */
593 #ifdef CONFIG_NFSD_V3
595 * Check server access rights to a file system object
601 static struct accessmap nfs3_regaccess
[] = {
602 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
603 { NFS3_ACCESS_EXECUTE
, NFSD_MAY_EXEC
},
604 { NFS3_ACCESS_MODIFY
, NFSD_MAY_WRITE
|NFSD_MAY_TRUNC
},
605 { NFS3_ACCESS_EXTEND
, NFSD_MAY_WRITE
},
607 #ifdef CONFIG_NFSD_V4
608 { NFS4_ACCESS_XAREAD
, NFSD_MAY_READ
},
609 { NFS4_ACCESS_XAWRITE
, NFSD_MAY_WRITE
},
610 { NFS4_ACCESS_XALIST
, NFSD_MAY_READ
},
616 static struct accessmap nfs3_diraccess
[] = {
617 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
618 { NFS3_ACCESS_LOOKUP
, NFSD_MAY_EXEC
},
619 { NFS3_ACCESS_MODIFY
, NFSD_MAY_EXEC
|NFSD_MAY_WRITE
|NFSD_MAY_TRUNC
},
620 { NFS3_ACCESS_EXTEND
, NFSD_MAY_EXEC
|NFSD_MAY_WRITE
},
621 { NFS3_ACCESS_DELETE
, NFSD_MAY_REMOVE
},
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_anyaccess
[] = {
633 /* Some clients - Solaris 2.6 at least, make an access call
634 * to the server to check for access for things like /dev/null
635 * (which really, the server doesn't care about). So
636 * We provide simple access checking for them, looking
637 * mainly at mode bits, and we make sure to ignore read-only
640 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
641 { NFS3_ACCESS_EXECUTE
, NFSD_MAY_EXEC
},
642 { NFS3_ACCESS_MODIFY
, NFSD_MAY_WRITE
|NFSD_MAY_LOCAL_ACCESS
},
643 { NFS3_ACCESS_EXTEND
, NFSD_MAY_WRITE
|NFSD_MAY_LOCAL_ACCESS
},
649 nfsd_access(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, u32
*access
, u32
*supported
)
651 struct accessmap
*map
;
652 struct svc_export
*export
;
653 struct dentry
*dentry
;
654 u32 query
, result
= 0, sresult
= 0;
657 error
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_NOP
);
661 export
= fhp
->fh_export
;
662 dentry
= fhp
->fh_dentry
;
664 if (d_is_reg(dentry
))
665 map
= nfs3_regaccess
;
666 else if (d_is_dir(dentry
))
667 map
= nfs3_diraccess
;
669 map
= nfs3_anyaccess
;
673 for (; map
->access
; map
++) {
674 if (map
->access
& query
) {
677 sresult
|= map
->access
;
679 err2
= nfsd_permission(rqstp
, export
, dentry
, map
->how
);
682 result
|= map
->access
;
685 /* the following error codes just mean the access was not allowed,
686 * rather than an error occurred */
690 /* simply don't "or" in the access bit. */
700 *supported
= sresult
;
705 #endif /* CONFIG_NFSD_V3 */
707 int nfsd_open_break_lease(struct inode
*inode
, int access
)
711 if (access
& NFSD_MAY_NOT_BREAK_LEASE
)
713 mode
= (access
& NFSD_MAY_WRITE
) ? O_WRONLY
: O_RDONLY
;
714 return break_lease(inode
, mode
| O_NONBLOCK
);
718 * Open an existing file or directory.
719 * The may_flags argument indicates the type of open (read/write/lock)
720 * and additional flags.
721 * N.B. After this call fhp needs an fh_put
724 __nfsd_open(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, umode_t type
,
725 int may_flags
, struct file
**filp
)
730 int flags
= O_RDONLY
|O_LARGEFILE
;
734 path
.mnt
= fhp
->fh_export
->ex_path
.mnt
;
735 path
.dentry
= fhp
->fh_dentry
;
736 inode
= d_inode(path
.dentry
);
738 /* Disallow write access to files with the append-only bit set
739 * or any access when mandatory locking enabled
742 if (IS_APPEND(inode
) && (may_flags
& NFSD_MAY_WRITE
))
748 host_err
= nfsd_open_break_lease(inode
, may_flags
);
749 if (host_err
) /* NOMEM or WOULDBLOCK */
752 if (may_flags
& NFSD_MAY_WRITE
) {
753 if (may_flags
& NFSD_MAY_READ
)
754 flags
= O_RDWR
|O_LARGEFILE
;
756 flags
= O_WRONLY
|O_LARGEFILE
;
759 file
= dentry_open(&path
, flags
, current_cred());
761 host_err
= PTR_ERR(file
);
765 host_err
= ima_file_check(file
, may_flags
);
771 if (may_flags
& NFSD_MAY_64BIT_COOKIE
)
772 file
->f_mode
|= FMODE_64BITHASH
;
774 file
->f_mode
|= FMODE_32BITHASH
;
778 err
= nfserrno(host_err
);
784 nfsd_open(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, umode_t type
,
785 int may_flags
, struct file
**filp
)
789 validate_process_creds();
791 * If we get here, then the client has already done an "open",
792 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
793 * in case a chmod has now revoked permission.
795 * Arguably we should also allow the owner override for
796 * directories, but we never have and it doesn't seem to have
797 * caused anyone a problem. If we were to change this, note
798 * also that our filldir callbacks would need a variant of
799 * lookup_one_len that doesn't check permissions.
802 may_flags
|= NFSD_MAY_OWNER_OVERRIDE
;
803 err
= fh_verify(rqstp
, fhp
, type
, may_flags
);
805 err
= __nfsd_open(rqstp
, fhp
, type
, may_flags
, filp
);
806 validate_process_creds();
811 nfsd_open_verified(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, umode_t type
,
812 int may_flags
, struct file
**filp
)
816 validate_process_creds();
817 err
= __nfsd_open(rqstp
, fhp
, type
, may_flags
, filp
);
818 validate_process_creds();
823 * Grab and keep cached pages associated with a file in the svc_rqst
824 * so that they can be passed to the network sendmsg/sendpage routines
825 * directly. They will be released after the sending has completed.
828 nfsd_splice_actor(struct pipe_inode_info
*pipe
, struct pipe_buffer
*buf
,
829 struct splice_desc
*sd
)
831 struct svc_rqst
*rqstp
= sd
->u
.data
;
832 struct page
**pp
= rqstp
->rq_next_page
;
833 struct page
*page
= buf
->page
;
835 if (rqstp
->rq_res
.page_len
== 0) {
836 svc_rqst_replace_page(rqstp
, page
);
837 rqstp
->rq_res
.page_base
= buf
->offset
;
838 } else if (page
!= pp
[-1]) {
839 svc_rqst_replace_page(rqstp
, page
);
841 rqstp
->rq_res
.page_len
+= sd
->len
;
846 static int nfsd_direct_splice_actor(struct pipe_inode_info
*pipe
,
847 struct splice_desc
*sd
)
849 return __splice_from_pipe(pipe
, sd
, nfsd_splice_actor
);
852 static u32
nfsd_eof_on_read(struct file
*file
, loff_t offset
, ssize_t len
,
855 if (expected
!= 0 && len
== 0)
857 if (offset
+len
>= i_size_read(file_inode(file
)))
862 static __be32
nfsd_finish_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
863 struct file
*file
, loff_t offset
,
864 unsigned long *count
, u32
*eof
, ssize_t host_err
)
867 nfsd_stats_io_read_add(fhp
->fh_export
, host_err
);
868 *eof
= nfsd_eof_on_read(file
, offset
, host_err
, *count
);
870 fsnotify_access(file
);
871 trace_nfsd_read_io_done(rqstp
, fhp
, offset
, *count
);
874 trace_nfsd_read_err(rqstp
, fhp
, offset
, host_err
);
875 return nfserrno(host_err
);
879 __be32
nfsd_splice_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
880 struct file
*file
, loff_t offset
, unsigned long *count
,
883 struct splice_desc sd
= {
891 trace_nfsd_read_splice(rqstp
, fhp
, offset
, *count
);
892 rqstp
->rq_next_page
= rqstp
->rq_respages
+ 1;
893 host_err
= splice_direct_to_actor(file
, &sd
, nfsd_direct_splice_actor
);
894 return nfsd_finish_read(rqstp
, fhp
, file
, offset
, count
, eof
, host_err
);
897 __be32
nfsd_readv(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
898 struct file
*file
, loff_t offset
,
899 struct kvec
*vec
, int vlen
, unsigned long *count
,
902 struct iov_iter iter
;
903 loff_t ppos
= offset
;
906 trace_nfsd_read_vector(rqstp
, fhp
, offset
, *count
);
907 iov_iter_kvec(&iter
, READ
, vec
, vlen
, *count
);
908 host_err
= vfs_iter_read(file
, &iter
, &ppos
, 0);
909 return nfsd_finish_read(rqstp
, fhp
, file
, offset
, count
, eof
, host_err
);
913 * Gathered writes: If another process is currently writing to the file,
914 * there's a high chance this is another nfsd (triggered by a bulk write
915 * from a client's biod). Rather than syncing the file with each write
916 * request, we sleep for 10 msec.
918 * I don't know if this roughly approximates C. Juszak's idea of
919 * gathered writes, but it's a nice and simple solution (IMHO), and it
922 * Note: we do this only in the NFSv2 case, since v3 and higher have a
923 * better tool (separate unstable writes and commits) for solving this
926 static int wait_for_concurrent_writes(struct file
*file
)
928 struct inode
*inode
= file_inode(file
);
929 static ino_t last_ino
;
930 static dev_t last_dev
;
933 if (atomic_read(&inode
->i_writecount
) > 1
934 || (last_ino
== inode
->i_ino
&& last_dev
== inode
->i_sb
->s_dev
)) {
935 dprintk("nfsd: write defer %d\n", task_pid_nr(current
));
937 dprintk("nfsd: write resume %d\n", task_pid_nr(current
));
940 if (inode
->i_state
& I_DIRTY
) {
941 dprintk("nfsd: write sync %d\n", task_pid_nr(current
));
942 err
= vfs_fsync(file
, 0);
944 last_ino
= inode
->i_ino
;
945 last_dev
= inode
->i_sb
->s_dev
;
950 nfsd_vfs_write(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct nfsd_file
*nf
,
951 loff_t offset
, struct kvec
*vec
, int vlen
,
952 unsigned long *cnt
, int stable
,
955 struct file
*file
= nf
->nf_file
;
956 struct super_block
*sb
= file_inode(file
)->i_sb
;
957 struct svc_export
*exp
;
958 struct iov_iter iter
;
964 unsigned long exp_op_flags
= 0;
965 unsigned int pflags
= current
->flags
;
967 bool restore_flags
= false;
969 trace_nfsd_write_opened(rqstp
, fhp
, offset
, *cnt
);
972 exp_op_flags
= sb
->s_export_op
->flags
;
974 if (test_bit(RQ_LOCAL
, &rqstp
->rq_flags
) &&
975 !(exp_op_flags
& EXPORT_OP_REMOTE_FS
)) {
977 * We want throttling in balance_dirty_pages()
978 * and shrink_inactive_list() to only consider
979 * the backingdev we are writing to, so that nfs to
980 * localhost doesn't cause nfsd to lock up due to all
981 * the client's dirty pages or its congested queue.
983 current
->flags
|= PF_LOCAL_THROTTLE
;
984 restore_flags
= true;
987 exp
= fhp
->fh_export
;
988 use_wgather
= (rqstp
->rq_vers
== 2) && EX_WGATHER(exp
);
991 stable
= NFS_UNSTABLE
;
993 if (stable
&& !use_wgather
)
996 iov_iter_kvec(&iter
, WRITE
, vec
, vlen
, *cnt
);
997 since
= READ_ONCE(file
->f_wb_err
);
998 if (flags
& RWF_SYNC
) {
1000 nfsd_copy_boot_verifier(verf
,
1001 net_generic(SVC_NET(rqstp
),
1003 host_err
= vfs_iter_write(file
, &iter
, &pos
, flags
);
1005 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp
),
1009 nfsd_copy_boot_verifier(verf
,
1010 net_generic(SVC_NET(rqstp
),
1012 host_err
= vfs_iter_write(file
, &iter
, &pos
, flags
);
1015 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp
),
1020 nfsd_stats_io_write_add(exp
, *cnt
);
1021 fsnotify_modify(file
);
1022 host_err
= filemap_check_wb_err(file
->f_mapping
, since
);
1026 if (stable
&& use_wgather
) {
1027 host_err
= wait_for_concurrent_writes(file
);
1029 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp
),
1034 if (host_err
>= 0) {
1035 trace_nfsd_write_io_done(rqstp
, fhp
, offset
, *cnt
);
1038 trace_nfsd_write_err(rqstp
, fhp
, offset
, host_err
);
1039 nfserr
= nfserrno(host_err
);
1042 current_restore_flags(pflags
, PF_LOCAL_THROTTLE
);
1047 * Read data from a file. count must contain the requested read count
1048 * on entry. On return, *count contains the number of bytes actually read.
1049 * N.B. After this call fhp needs an fh_put
1051 __be32
nfsd_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1052 loff_t offset
, struct kvec
*vec
, int vlen
, unsigned long *count
,
1055 struct nfsd_file
*nf
;
1059 trace_nfsd_read_start(rqstp
, fhp
, offset
, *count
);
1060 err
= nfsd_file_acquire(rqstp
, fhp
, NFSD_MAY_READ
, &nf
);
1065 if (file
->f_op
->splice_read
&& test_bit(RQ_SPLICE_OK
, &rqstp
->rq_flags
))
1066 err
= nfsd_splice_read(rqstp
, fhp
, file
, offset
, count
, eof
);
1068 err
= nfsd_readv(rqstp
, fhp
, file
, offset
, vec
, vlen
, count
, eof
);
1072 trace_nfsd_read_done(rqstp
, fhp
, offset
, *count
);
1078 * Write data to a file.
1079 * The stable flag requests synchronous writes.
1080 * N.B. After this call fhp needs an fh_put
1083 nfsd_write(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, loff_t offset
,
1084 struct kvec
*vec
, int vlen
, unsigned long *cnt
, int stable
,
1087 struct nfsd_file
*nf
;
1090 trace_nfsd_write_start(rqstp
, fhp
, offset
, *cnt
);
1092 err
= nfsd_file_acquire(rqstp
, fhp
, NFSD_MAY_WRITE
, &nf
);
1096 err
= nfsd_vfs_write(rqstp
, fhp
, nf
, offset
, vec
,
1097 vlen
, cnt
, stable
, verf
);
1100 trace_nfsd_write_done(rqstp
, fhp
, offset
, *cnt
);
1104 #ifdef CONFIG_NFSD_V3
1106 * Commit all pending writes to stable storage.
1108 * Note: we only guarantee that data that lies within the range specified
1109 * by the 'offset' and 'count' parameters will be synced.
1111 * Unfortunately we cannot lock the file to make sure we return full WCC
1112 * data to the client, as locking happens lower down in the filesystem.
1115 nfsd_commit(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1116 loff_t offset
, unsigned long count
, __be32
*verf
)
1118 struct nfsd_file
*nf
;
1119 loff_t end
= LLONG_MAX
;
1120 __be32 err
= nfserr_inval
;
1125 end
= offset
+ (loff_t
)count
- 1;
1130 err
= nfsd_file_acquire(rqstp
, fhp
,
1131 NFSD_MAY_WRITE
|NFSD_MAY_NOT_BREAK_LEASE
, &nf
);
1134 if (EX_ISSYNC(fhp
->fh_export
)) {
1135 errseq_t since
= READ_ONCE(nf
->nf_file
->f_wb_err
);
1138 err2
= vfs_fsync_range(nf
->nf_file
, offset
, end
, 0);
1141 nfsd_copy_boot_verifier(verf
, net_generic(nf
->nf_net
,
1143 err2
= filemap_check_wb_err(nf
->nf_file
->f_mapping
,
1145 err
= nfserrno(err2
);
1148 err
= nfserr_notsupp
;
1151 nfsd_reset_boot_verifier(net_generic(nf
->nf_net
,
1153 err
= nfserrno(err2
);
1156 nfsd_copy_boot_verifier(verf
, net_generic(nf
->nf_net
,
1163 #endif /* CONFIG_NFSD_V3 */
1166 nfsd_create_setattr(struct svc_rqst
*rqstp
, struct svc_fh
*resfhp
,
1170 * Mode has already been set earlier in create:
1172 iap
->ia_valid
&= ~ATTR_MODE
;
1174 * Setting uid/gid works only for root. Irix appears to
1175 * send along the gid on create when it tries to implement
1176 * setgid directories via NFS:
1178 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID
))
1179 iap
->ia_valid
&= ~(ATTR_UID
|ATTR_GID
);
1181 return nfsd_setattr(rqstp
, resfhp
, iap
, 0, (time64_t
)0);
1182 /* Callers expect file metadata to be committed here */
1183 return nfserrno(commit_metadata(resfhp
));
1186 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1187 * setting size to 0 may fail for some specific file systems by the permission
1188 * checking which requires WRITE permission but the mode is 000.
1189 * we ignore the resizing(to 0) on the just new created file, since the size is
1190 * 0 after file created.
1192 * call this only after vfs_create() is called.
1195 nfsd_check_ignore_resizing(struct iattr
*iap
)
1197 if ((iap
->ia_valid
& ATTR_SIZE
) && (iap
->ia_size
== 0))
1198 iap
->ia_valid
&= ~ATTR_SIZE
;
1201 /* The parent directory should already be locked: */
1203 nfsd_create_locked(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1204 char *fname
, int flen
, struct iattr
*iap
,
1205 int type
, dev_t rdev
, struct svc_fh
*resfhp
)
1207 struct dentry
*dentry
, *dchild
;
1213 dentry
= fhp
->fh_dentry
;
1214 dirp
= d_inode(dentry
);
1216 dchild
= dget(resfhp
->fh_dentry
);
1217 if (!fhp
->fh_locked
) {
1218 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
1224 err
= nfsd_permission(rqstp
, fhp
->fh_export
, dentry
, NFSD_MAY_CREATE
);
1228 if (!(iap
->ia_valid
& ATTR_MODE
))
1230 iap
->ia_mode
= (iap
->ia_mode
& S_IALLUGO
) | type
;
1232 if (!IS_POSIXACL(dirp
))
1233 iap
->ia_mode
&= ~current_umask();
1239 host_err
= vfs_create(&init_user_ns
, dirp
, dchild
, iap
->ia_mode
, true);
1241 nfsd_check_ignore_resizing(iap
);
1244 host_err
= vfs_mkdir(&init_user_ns
, dirp
, dchild
, iap
->ia_mode
);
1245 if (!host_err
&& unlikely(d_unhashed(dchild
))) {
1247 d
= lookup_one_len(dchild
->d_name
.name
,
1249 dchild
->d_name
.len
);
1251 host_err
= PTR_ERR(d
);
1254 if (unlikely(d_is_negative(d
))) {
1256 err
= nfserr_serverfault
;
1259 dput(resfhp
->fh_dentry
);
1260 resfhp
->fh_dentry
= dget(d
);
1261 err
= fh_update(resfhp
);
1272 host_err
= vfs_mknod(&init_user_ns
, dirp
, dchild
,
1273 iap
->ia_mode
, rdev
);
1276 printk(KERN_WARNING
"nfsd: bad file type %o in nfsd_create\n",
1283 err
= nfsd_create_setattr(rqstp
, resfhp
, iap
);
1286 * nfsd_create_setattr already committed the child. Transactional
1287 * filesystems had a chance to commit changes for both parent and
1288 * child simultaneously making the following commit_metadata a
1291 err2
= nfserrno(commit_metadata(fhp
));
1295 * Update the file handle to get the new inode info.
1298 err
= fh_update(resfhp
);
1304 err
= nfserrno(host_err
);
1309 * Create a filesystem object (regular, directory, special).
1310 * Note that the parent directory is left locked.
1312 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1315 nfsd_create(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1316 char *fname
, int flen
, struct iattr
*iap
,
1317 int type
, dev_t rdev
, struct svc_fh
*resfhp
)
1319 struct dentry
*dentry
, *dchild
= NULL
;
1323 if (isdotent(fname
, flen
))
1324 return nfserr_exist
;
1326 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_NOP
);
1330 dentry
= fhp
->fh_dentry
;
1332 host_err
= fh_want_write(fhp
);
1334 return nfserrno(host_err
);
1336 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1337 dchild
= lookup_one_len(fname
, dentry
, flen
);
1338 host_err
= PTR_ERR(dchild
);
1340 return nfserrno(host_err
);
1341 err
= fh_compose(resfhp
, fhp
->fh_export
, dchild
, fhp
);
1343 * We unconditionally drop our ref to dchild as fh_compose will have
1344 * already grabbed its own ref for it.
1349 return nfsd_create_locked(rqstp
, fhp
, fname
, flen
, iap
, type
,
1353 #ifdef CONFIG_NFSD_V3
1356 * NFSv3 and NFSv4 version of nfsd_create
1359 do_nfsd_create(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1360 char *fname
, int flen
, struct iattr
*iap
,
1361 struct svc_fh
*resfhp
, int createmode
, u32
*verifier
,
1362 bool *truncp
, bool *created
)
1364 struct dentry
*dentry
, *dchild
= NULL
;
1368 __u32 v_mtime
=0, v_atime
=0;
1374 if (isdotent(fname
, flen
))
1376 if (!(iap
->ia_valid
& ATTR_MODE
))
1378 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_EXEC
);
1382 dentry
= fhp
->fh_dentry
;
1383 dirp
= d_inode(dentry
);
1385 host_err
= fh_want_write(fhp
);
1389 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1392 * Compose the response file handle.
1394 dchild
= lookup_one_len(fname
, dentry
, flen
);
1395 host_err
= PTR_ERR(dchild
);
1399 /* If file doesn't exist, check for permissions to create one */
1400 if (d_really_is_negative(dchild
)) {
1401 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1406 err
= fh_compose(resfhp
, fhp
->fh_export
, dchild
, fhp
);
1410 if (nfsd_create_is_exclusive(createmode
)) {
1411 /* solaris7 gets confused (bugid 4218508) if these have
1412 * the high bit set, so just clear the high bits. If this is
1413 * ever changed to use different attrs for storing the
1414 * verifier, then do_open_lookup() will also need to be fixed
1417 v_mtime
= verifier
[0]&0x7fffffff;
1418 v_atime
= verifier
[1]&0x7fffffff;
1421 if (d_really_is_positive(dchild
)) {
1424 switch (createmode
) {
1425 case NFS3_CREATE_UNCHECKED
:
1426 if (! d_is_reg(dchild
))
1429 /* in nfsv4, we need to treat this case a little
1430 * differently. we don't want to truncate the
1431 * file now; this would be wrong if the OPEN
1432 * fails for some other reason. furthermore,
1433 * if the size is nonzero, we should ignore it
1434 * according to spec!
1436 *truncp
= (iap
->ia_valid
& ATTR_SIZE
) && !iap
->ia_size
;
1439 iap
->ia_valid
&= ATTR_SIZE
;
1443 case NFS3_CREATE_EXCLUSIVE
:
1444 if ( d_inode(dchild
)->i_mtime
.tv_sec
== v_mtime
1445 && d_inode(dchild
)->i_atime
.tv_sec
== v_atime
1446 && d_inode(dchild
)->i_size
== 0 ) {
1452 case NFS4_CREATE_EXCLUSIVE4_1
:
1453 if ( d_inode(dchild
)->i_mtime
.tv_sec
== v_mtime
1454 && d_inode(dchild
)->i_atime
.tv_sec
== v_atime
1455 && d_inode(dchild
)->i_size
== 0 ) {
1461 case NFS3_CREATE_GUARDED
:
1468 if (!IS_POSIXACL(dirp
))
1469 iap
->ia_mode
&= ~current_umask();
1471 host_err
= vfs_create(&init_user_ns
, dirp
, dchild
, iap
->ia_mode
, true);
1479 nfsd_check_ignore_resizing(iap
);
1481 if (nfsd_create_is_exclusive(createmode
)) {
1482 /* Cram the verifier into atime/mtime */
1483 iap
->ia_valid
= ATTR_MTIME
|ATTR_ATIME
1484 | ATTR_MTIME_SET
|ATTR_ATIME_SET
;
1485 /* XXX someone who knows this better please fix it for nsec */
1486 iap
->ia_mtime
.tv_sec
= v_mtime
;
1487 iap
->ia_atime
.tv_sec
= v_atime
;
1488 iap
->ia_mtime
.tv_nsec
= 0;
1489 iap
->ia_atime
.tv_nsec
= 0;
1493 err
= nfsd_create_setattr(rqstp
, resfhp
, iap
);
1496 * nfsd_create_setattr already committed the child
1497 * (and possibly also the parent).
1500 err
= nfserrno(commit_metadata(fhp
));
1503 * Update the filehandle to get the new inode info.
1506 err
= fh_update(resfhp
);
1510 if (dchild
&& !IS_ERR(dchild
))
1516 err
= nfserrno(host_err
);
1519 #endif /* CONFIG_NFSD_V3 */
1522 * Read a symlink. On entry, *lenp must contain the maximum path length that
1523 * fits into the buffer. On return, it contains the true length.
1524 * N.B. After this call fhp needs an fh_put
1527 nfsd_readlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *buf
, int *lenp
)
1532 DEFINE_DELAYED_CALL(done
);
1535 err
= fh_verify(rqstp
, fhp
, S_IFLNK
, NFSD_MAY_NOP
);
1539 path
.mnt
= fhp
->fh_export
->ex_path
.mnt
;
1540 path
.dentry
= fhp
->fh_dentry
;
1542 if (unlikely(!d_is_symlink(path
.dentry
)))
1543 return nfserr_inval
;
1547 link
= vfs_get_link(path
.dentry
, &done
);
1549 return nfserrno(PTR_ERR(link
));
1554 memcpy(buf
, link
, *lenp
);
1555 do_delayed_call(&done
);
1560 * Create a symlink and look up its inode
1561 * N.B. After this call _both_ fhp and resfhp need an fh_put
1564 nfsd_symlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1565 char *fname
, int flen
,
1567 struct svc_fh
*resfhp
)
1569 struct dentry
*dentry
, *dnew
;
1574 if (!flen
|| path
[0] == '\0')
1577 if (isdotent(fname
, flen
))
1580 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1584 host_err
= fh_want_write(fhp
);
1589 dentry
= fhp
->fh_dentry
;
1590 dnew
= lookup_one_len(fname
, dentry
, flen
);
1591 host_err
= PTR_ERR(dnew
);
1595 host_err
= vfs_symlink(&init_user_ns
, d_inode(dentry
), dnew
, path
);
1596 err
= nfserrno(host_err
);
1599 err
= nfserrno(commit_metadata(fhp
));
1603 cerr
= fh_compose(resfhp
, fhp
->fh_export
, dnew
, fhp
);
1605 if (err
==0) err
= cerr
;
1610 err
= nfserrno(host_err
);
1616 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1619 nfsd_link(struct svc_rqst
*rqstp
, struct svc_fh
*ffhp
,
1620 char *name
, int len
, struct svc_fh
*tfhp
)
1622 struct dentry
*ddir
, *dnew
, *dold
;
1627 err
= fh_verify(rqstp
, ffhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1630 err
= fh_verify(rqstp
, tfhp
, 0, NFSD_MAY_NOP
);
1634 if (d_is_dir(tfhp
->fh_dentry
))
1640 if (isdotent(name
, len
))
1643 host_err
= fh_want_write(tfhp
);
1645 err
= nfserrno(host_err
);
1649 fh_lock_nested(ffhp
, I_MUTEX_PARENT
);
1650 ddir
= ffhp
->fh_dentry
;
1651 dirp
= d_inode(ddir
);
1653 dnew
= lookup_one_len(name
, ddir
, len
);
1654 host_err
= PTR_ERR(dnew
);
1658 dold
= tfhp
->fh_dentry
;
1661 if (d_really_is_negative(dold
))
1663 host_err
= vfs_link(dold
, &init_user_ns
, dirp
, dnew
, NULL
);
1666 err
= nfserrno(commit_metadata(ffhp
));
1668 err
= nfserrno(commit_metadata(tfhp
));
1670 if (host_err
== -EXDEV
&& rqstp
->rq_vers
== 2)
1673 err
= nfserrno(host_err
);
1679 fh_drop_write(tfhp
);
1684 err
= nfserrno(host_err
);
1689 nfsd_close_cached_files(struct dentry
*dentry
)
1691 struct inode
*inode
= d_inode(dentry
);
1693 if (inode
&& S_ISREG(inode
->i_mode
))
1694 nfsd_file_close_inode_sync(inode
);
1698 nfsd_has_cached_files(struct dentry
*dentry
)
1701 struct inode
*inode
= d_inode(dentry
);
1703 if (inode
&& S_ISREG(inode
->i_mode
))
1704 ret
= nfsd_file_is_cached(inode
);
1710 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1713 nfsd_rename(struct svc_rqst
*rqstp
, struct svc_fh
*ffhp
, char *fname
, int flen
,
1714 struct svc_fh
*tfhp
, char *tname
, int tlen
)
1716 struct dentry
*fdentry
, *tdentry
, *odentry
, *ndentry
, *trap
;
1717 struct inode
*fdir
, *tdir
;
1720 bool close_cached
= false;
1722 err
= fh_verify(rqstp
, ffhp
, S_IFDIR
, NFSD_MAY_REMOVE
);
1725 err
= fh_verify(rqstp
, tfhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1729 fdentry
= ffhp
->fh_dentry
;
1730 fdir
= d_inode(fdentry
);
1732 tdentry
= tfhp
->fh_dentry
;
1733 tdir
= d_inode(tdentry
);
1736 if (!flen
|| isdotent(fname
, flen
) || !tlen
|| isdotent(tname
, tlen
))
1740 host_err
= fh_want_write(ffhp
);
1742 err
= nfserrno(host_err
);
1746 /* cannot use fh_lock as we need deadlock protective ordering
1747 * so do it by hand */
1748 trap
= lock_rename(tdentry
, fdentry
);
1749 ffhp
->fh_locked
= tfhp
->fh_locked
= true;
1753 odentry
= lookup_one_len(fname
, fdentry
, flen
);
1754 host_err
= PTR_ERR(odentry
);
1755 if (IS_ERR(odentry
))
1759 if (d_really_is_negative(odentry
))
1762 if (odentry
== trap
)
1765 ndentry
= lookup_one_len(tname
, tdentry
, tlen
);
1766 host_err
= PTR_ERR(ndentry
);
1767 if (IS_ERR(ndentry
))
1769 host_err
= -ENOTEMPTY
;
1770 if (ndentry
== trap
)
1774 if (ffhp
->fh_export
->ex_path
.mnt
!= tfhp
->fh_export
->ex_path
.mnt
)
1776 if (ffhp
->fh_export
->ex_path
.dentry
!= tfhp
->fh_export
->ex_path
.dentry
)
1779 if ((ndentry
->d_sb
->s_export_op
->flags
& EXPORT_OP_CLOSE_BEFORE_UNLINK
) &&
1780 nfsd_has_cached_files(ndentry
)) {
1781 close_cached
= true;
1784 struct renamedata rd
= {
1785 .old_mnt_userns
= &init_user_ns
,
1787 .old_dentry
= odentry
,
1788 .new_mnt_userns
= &init_user_ns
,
1790 .new_dentry
= ndentry
,
1792 host_err
= vfs_rename(&rd
);
1794 host_err
= commit_metadata(tfhp
);
1796 host_err
= commit_metadata(ffhp
);
1804 err
= nfserrno(host_err
);
1806 * We cannot rely on fh_unlock on the two filehandles,
1807 * as that would do the wrong thing if the two directories
1808 * were the same, so again we do it by hand.
1810 if (!close_cached
) {
1811 fill_post_wcc(ffhp
);
1812 fill_post_wcc(tfhp
);
1814 unlock_rename(tdentry
, fdentry
);
1815 ffhp
->fh_locked
= tfhp
->fh_locked
= false;
1816 fh_drop_write(ffhp
);
1819 * If the target dentry has cached open files, then we need to try to
1820 * close them prior to doing the rename. Flushing delayed fput
1821 * shouldn't be done with locks held however, so we delay it until this
1822 * point and then reattempt the whole shebang.
1825 close_cached
= false;
1826 nfsd_close_cached_files(ndentry
);
1835 * Unlink a file or directory
1836 * N.B. After this call fhp needs an fh_put
1839 nfsd_unlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, int type
,
1840 char *fname
, int flen
)
1842 struct dentry
*dentry
, *rdentry
;
1844 struct inode
*rinode
;
1849 if (!flen
|| isdotent(fname
, flen
))
1851 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_REMOVE
);
1855 host_err
= fh_want_write(fhp
);
1859 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1860 dentry
= fhp
->fh_dentry
;
1861 dirp
= d_inode(dentry
);
1863 rdentry
= lookup_one_len(fname
, dentry
, flen
);
1864 host_err
= PTR_ERR(rdentry
);
1865 if (IS_ERR(rdentry
))
1866 goto out_drop_write
;
1868 if (d_really_is_negative(rdentry
)) {
1871 goto out_drop_write
;
1873 rinode
= d_inode(rdentry
);
1877 type
= d_inode(rdentry
)->i_mode
& S_IFMT
;
1879 if (type
!= S_IFDIR
) {
1880 if (rdentry
->d_sb
->s_export_op
->flags
& EXPORT_OP_CLOSE_BEFORE_UNLINK
)
1881 nfsd_close_cached_files(rdentry
);
1882 host_err
= vfs_unlink(&init_user_ns
, dirp
, rdentry
, NULL
);
1884 host_err
= vfs_rmdir(&init_user_ns
, dirp
, rdentry
);
1889 host_err
= commit_metadata(fhp
);
1891 iput(rinode
); /* truncate the inode here */
1896 if (host_err
== -EBUSY
) {
1897 /* name is mounted-on. There is no perfect
1900 if (nfsd_v4client(rqstp
))
1901 err
= nfserr_file_open
;
1905 err
= nfserrno(host_err
);
1912 * We do this buffering because we must not call back into the file
1913 * system's ->lookup() method from the filldir callback. That may well
1914 * deadlock a number of file systems.
1916 * This is based heavily on the implementation of same in XFS.
1918 struct buffered_dirent
{
1922 unsigned int d_type
;
1926 struct readdir_data
{
1927 struct dir_context ctx
;
1933 static int nfsd_buffered_filldir(struct dir_context
*ctx
, const char *name
,
1934 int namlen
, loff_t offset
, u64 ino
,
1935 unsigned int d_type
)
1937 struct readdir_data
*buf
=
1938 container_of(ctx
, struct readdir_data
, ctx
);
1939 struct buffered_dirent
*de
= (void *)(buf
->dirent
+ buf
->used
);
1940 unsigned int reclen
;
1942 reclen
= ALIGN(sizeof(struct buffered_dirent
) + namlen
, sizeof(u64
));
1943 if (buf
->used
+ reclen
> PAGE_SIZE
) {
1948 de
->namlen
= namlen
;
1949 de
->offset
= offset
;
1951 de
->d_type
= d_type
;
1952 memcpy(de
->name
, name
, namlen
);
1953 buf
->used
+= reclen
;
1958 static __be32
nfsd_buffered_readdir(struct file
*file
, struct svc_fh
*fhp
,
1959 nfsd_filldir_t func
, struct readdir_cd
*cdp
,
1962 struct buffered_dirent
*de
;
1966 struct readdir_data buf
= {
1967 .ctx
.actor
= nfsd_buffered_filldir
,
1968 .dirent
= (void *)__get_free_page(GFP_KERNEL
)
1972 return nfserrno(-ENOMEM
);
1977 unsigned int reclen
;
1979 cdp
->err
= nfserr_eof
; /* will be cleared on successful read */
1983 host_err
= iterate_dir(file
, &buf
.ctx
);
1995 de
= (struct buffered_dirent
*)buf
.dirent
;
1997 offset
= de
->offset
;
1999 if (func(cdp
, de
->name
, de
->namlen
, de
->offset
,
2000 de
->ino
, de
->d_type
))
2003 if (cdp
->err
!= nfs_ok
)
2006 trace_nfsd_dirent(fhp
, de
->ino
, de
->name
, de
->namlen
);
2008 reclen
= ALIGN(sizeof(*de
) + de
->namlen
,
2011 de
= (struct buffered_dirent
*)((char *)de
+ reclen
);
2013 if (size
> 0) /* We bailed out early */
2016 offset
= vfs_llseek(file
, 0, SEEK_CUR
);
2019 free_page((unsigned long)(buf
.dirent
));
2022 return nfserrno(host_err
);
2029 * Read entries from a directory.
2030 * The NFSv3/4 verifier we ignore for now.
2033 nfsd_readdir(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, loff_t
*offsetp
,
2034 struct readdir_cd
*cdp
, nfsd_filldir_t func
)
2038 loff_t offset
= *offsetp
;
2039 int may_flags
= NFSD_MAY_READ
;
2041 /* NFSv2 only supports 32 bit cookies */
2042 if (rqstp
->rq_vers
> 2)
2043 may_flags
|= NFSD_MAY_64BIT_COOKIE
;
2045 err
= nfsd_open(rqstp
, fhp
, S_IFDIR
, may_flags
, &file
);
2049 offset
= vfs_llseek(file
, offset
, SEEK_SET
);
2051 err
= nfserrno((int)offset
);
2055 err
= nfsd_buffered_readdir(file
, fhp
, func
, cdp
, offsetp
);
2057 if (err
== nfserr_eof
|| err
== nfserr_toosmall
)
2058 err
= nfs_ok
; /* can still be found in ->err */
2066 * Get file system stats
2067 * N.B. After this call fhp needs an fh_put
2070 nfsd_statfs(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct kstatfs
*stat
, int access
)
2074 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_NOP
| access
);
2076 struct path path
= {
2077 .mnt
= fhp
->fh_export
->ex_path
.mnt
,
2078 .dentry
= fhp
->fh_dentry
,
2080 if (vfs_statfs(&path
, stat
))
2086 static int exp_rdonly(struct svc_rqst
*rqstp
, struct svc_export
*exp
)
2088 return nfsexp_flags(rqstp
, exp
) & NFSEXP_READONLY
;
2091 #ifdef CONFIG_NFSD_V4
2093 * Helper function to translate error numbers. In the case of xattr operations,
2094 * some error codes need to be translated outside of the standard translations.
2096 * ENODATA needs to be translated to nfserr_noxattr.
2097 * E2BIG to nfserr_xattr2big.
2099 * Additionally, vfs_listxattr can return -ERANGE. This means that the
2100 * file has too many extended attributes to retrieve inside an
2101 * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
2102 * filesystems will allow the adding of extended attributes until they hit
2103 * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
2104 * So, at that point, the attributes are present and valid, but can't
2105 * be retrieved using listxattr, since the upper level xattr code enforces
2106 * the XATTR_LIST_MAX limit.
2108 * This bug means that we need to deal with listxattr returning -ERANGE. The
2109 * best mapping is to return TOOSMALL.
2112 nfsd_xattr_errno(int err
)
2116 return nfserr_noxattr
;
2118 return nfserr_xattr2big
;
2120 return nfserr_toosmall
;
2122 return nfserrno(err
);
2126 * Retrieve the specified user extended attribute. To avoid always
2127 * having to allocate the maximum size (since we are not getting
2128 * a maximum size from the RPC), do a probe + alloc. Hold a reader
2129 * lock on i_rwsem to prevent the extended attribute from changing
2130 * size while we're doing this.
2133 nfsd_getxattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *name
,
2134 void **bufp
, int *lenp
)
2139 struct inode
*inode
;
2140 struct dentry
*dentry
;
2142 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_READ
);
2147 dentry
= fhp
->fh_dentry
;
2148 inode
= d_inode(dentry
);
2150 inode_lock_shared(inode
);
2152 len
= vfs_getxattr(&init_user_ns
, dentry
, name
, NULL
, 0);
2155 * Zero-length attribute, just return.
2164 err
= nfsd_xattr_errno(len
);
2169 err
= nfserr_toosmall
;
2173 buf
= kvmalloc(len
, GFP_KERNEL
| GFP_NOFS
);
2175 err
= nfserr_jukebox
;
2179 len
= vfs_getxattr(&init_user_ns
, dentry
, name
, buf
, len
);
2183 err
= nfsd_xattr_errno(len
);
2190 inode_unlock_shared(inode
);
2196 * Retrieve the xattr names. Since we can't know how many are
2197 * user extended attributes, we must get all attributes here,
2198 * and have the XDR encode filter out the "user." ones.
2200 * While this could always just allocate an XATTR_LIST_MAX
2201 * buffer, that's a waste, so do a probe + allocate. To
2202 * avoid any changes between the probe and allocate, wrap
2203 * this in inode_lock.
2206 nfsd_listxattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char **bufp
,
2212 struct inode
*inode
;
2213 struct dentry
*dentry
;
2215 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_READ
);
2219 dentry
= fhp
->fh_dentry
;
2220 inode
= d_inode(dentry
);
2223 inode_lock_shared(inode
);
2225 len
= vfs_listxattr(dentry
, NULL
, 0);
2227 err
= nfsd_xattr_errno(len
);
2231 if (len
> XATTR_LIST_MAX
) {
2232 err
= nfserr_xattr2big
;
2237 * We're holding i_rwsem - use GFP_NOFS.
2239 buf
= kvmalloc(len
, GFP_KERNEL
| GFP_NOFS
);
2241 err
= nfserr_jukebox
;
2245 len
= vfs_listxattr(dentry
, buf
, len
);
2248 err
= nfsd_xattr_errno(len
);
2257 inode_unlock_shared(inode
);
2263 * Removexattr and setxattr need to call fh_lock to both lock the inode
2264 * and set the change attribute. Since the top-level vfs_removexattr
2265 * and vfs_setxattr calls already do their own inode_lock calls, call
2266 * the _locked variant. Pass in a NULL pointer for delegated_inode,
2267 * and let the client deal with NFS4ERR_DELAY (same as with e.g.
2268 * setattr and remove).
2271 nfsd_removexattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *name
)
2276 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_WRITE
);
2280 ret
= fh_want_write(fhp
);
2282 return nfserrno(ret
);
2286 ret
= __vfs_removexattr_locked(&init_user_ns
, fhp
->fh_dentry
,
2292 return nfsd_xattr_errno(ret
);
2296 nfsd_setxattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *name
,
2297 void *buf
, u32 len
, u32 flags
)
2302 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_WRITE
);
2306 ret
= fh_want_write(fhp
);
2308 return nfserrno(ret
);
2311 ret
= __vfs_setxattr_locked(&init_user_ns
, fhp
->fh_dentry
, name
, buf
,
2317 return nfsd_xattr_errno(ret
);
2322 * Check for a user's access permissions to this inode.
2325 nfsd_permission(struct svc_rqst
*rqstp
, struct svc_export
*exp
,
2326 struct dentry
*dentry
, int acc
)
2328 struct inode
*inode
= d_inode(dentry
);
2331 if ((acc
& NFSD_MAY_MASK
) == NFSD_MAY_NOP
)
2334 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2336 (acc
& NFSD_MAY_READ
)? " read" : "",
2337 (acc
& NFSD_MAY_WRITE
)? " write" : "",
2338 (acc
& NFSD_MAY_EXEC
)? " exec" : "",
2339 (acc
& NFSD_MAY_SATTR
)? " sattr" : "",
2340 (acc
& NFSD_MAY_TRUNC
)? " trunc" : "",
2341 (acc
& NFSD_MAY_LOCK
)? " lock" : "",
2342 (acc
& NFSD_MAY_OWNER_OVERRIDE
)? " owneroverride" : "",
2344 IS_IMMUTABLE(inode
)? " immut" : "",
2345 IS_APPEND(inode
)? " append" : "",
2346 __mnt_is_readonly(exp
->ex_path
.mnt
)? " ro" : "");
2347 dprintk(" owner %d/%d user %d/%d\n",
2348 inode
->i_uid
, inode
->i_gid
, current_fsuid(), current_fsgid());
2351 /* Normally we reject any write/sattr etc access on a read-only file
2352 * system. But if it is IRIX doing check on write-access for a
2353 * device special file, we ignore rofs.
2355 if (!(acc
& NFSD_MAY_LOCAL_ACCESS
))
2356 if (acc
& (NFSD_MAY_WRITE
| NFSD_MAY_SATTR
| NFSD_MAY_TRUNC
)) {
2357 if (exp_rdonly(rqstp
, exp
) ||
2358 __mnt_is_readonly(exp
->ex_path
.mnt
))
2360 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode
))
2363 if ((acc
& NFSD_MAY_TRUNC
) && IS_APPEND(inode
))
2366 if (acc
& NFSD_MAY_LOCK
) {
2367 /* If we cannot rely on authentication in NLM requests,
2368 * just allow locks, otherwise require read permission, or
2371 if (exp
->ex_flags
& NFSEXP_NOAUTHNLM
)
2374 acc
= NFSD_MAY_READ
| NFSD_MAY_OWNER_OVERRIDE
;
2377 * The file owner always gets access permission for accesses that
2378 * would normally be checked at open time. This is to make
2379 * file access work even when the client has done a fchmod(fd, 0).
2381 * However, `cp foo bar' should fail nevertheless when bar is
2382 * readonly. A sensible way to do this might be to reject all
2383 * attempts to truncate a read-only file, because a creat() call
2384 * always implies file truncation.
2385 * ... but this isn't really fair. A process may reasonably call
2386 * ftruncate on an open file descriptor on a file with perm 000.
2387 * We must trust the client to do permission checking - using "ACCESS"
2390 if ((acc
& NFSD_MAY_OWNER_OVERRIDE
) &&
2391 uid_eq(inode
->i_uid
, current_fsuid()))
2394 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2395 err
= inode_permission(&init_user_ns
, inode
,
2396 acc
& (MAY_READ
| MAY_WRITE
| MAY_EXEC
));
2398 /* Allow read access to binaries even when mode 111 */
2399 if (err
== -EACCES
&& S_ISREG(inode
->i_mode
) &&
2400 (acc
== (NFSD_MAY_READ
| NFSD_MAY_OWNER_OVERRIDE
) ||
2401 acc
== (NFSD_MAY_READ
| NFSD_MAY_READ_IF_EXEC
)))
2402 err
= inode_permission(&init_user_ns
, inode
, MAY_EXEC
);
2404 return err
? nfserrno(err
) : 0;