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
)
566 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
567 * thread and client rpc slot. The choice of 4MB is somewhat
568 * arbitrary. We might instead base this on r/wsize, or make it
569 * tunable, or use a time instead of a byte limit, or implement
570 * asynchronous copy. In theory a client could also recognize a
571 * limit like this and pipeline multiple COPY requests.
573 count
= min_t(u64
, count
, 1 << 22);
574 ret
= vfs_copy_file_range(src
, src_pos
, dst
, dst_pos
, count
, 0);
576 if (ret
== -EOPNOTSUPP
|| ret
== -EXDEV
)
577 ret
= generic_copy_file_range(src
, src_pos
, dst
, dst_pos
,
582 __be32
nfsd4_vfs_fallocate(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
583 struct file
*file
, loff_t offset
, loff_t len
,
588 if (!S_ISREG(file_inode(file
)->i_mode
))
591 error
= vfs_fallocate(file
, flags
, offset
, len
);
593 error
= commit_metadata(fhp
);
595 return nfserrno(error
);
597 #endif /* defined(CONFIG_NFSD_V4) */
599 #ifdef CONFIG_NFSD_V3
601 * Check server access rights to a file system object
607 static struct accessmap nfs3_regaccess
[] = {
608 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
609 { NFS3_ACCESS_EXECUTE
, NFSD_MAY_EXEC
},
610 { NFS3_ACCESS_MODIFY
, NFSD_MAY_WRITE
|NFSD_MAY_TRUNC
},
611 { NFS3_ACCESS_EXTEND
, NFSD_MAY_WRITE
},
613 #ifdef CONFIG_NFSD_V4
614 { NFS4_ACCESS_XAREAD
, NFSD_MAY_READ
},
615 { NFS4_ACCESS_XAWRITE
, NFSD_MAY_WRITE
},
616 { NFS4_ACCESS_XALIST
, NFSD_MAY_READ
},
622 static struct accessmap nfs3_diraccess
[] = {
623 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
624 { NFS3_ACCESS_LOOKUP
, NFSD_MAY_EXEC
},
625 { NFS3_ACCESS_MODIFY
, NFSD_MAY_EXEC
|NFSD_MAY_WRITE
|NFSD_MAY_TRUNC
},
626 { NFS3_ACCESS_EXTEND
, NFSD_MAY_EXEC
|NFSD_MAY_WRITE
},
627 { NFS3_ACCESS_DELETE
, NFSD_MAY_REMOVE
},
629 #ifdef CONFIG_NFSD_V4
630 { NFS4_ACCESS_XAREAD
, NFSD_MAY_READ
},
631 { NFS4_ACCESS_XAWRITE
, NFSD_MAY_WRITE
},
632 { NFS4_ACCESS_XALIST
, NFSD_MAY_READ
},
638 static struct accessmap nfs3_anyaccess
[] = {
639 /* Some clients - Solaris 2.6 at least, make an access call
640 * to the server to check for access for things like /dev/null
641 * (which really, the server doesn't care about). So
642 * We provide simple access checking for them, looking
643 * mainly at mode bits, and we make sure to ignore read-only
646 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
647 { NFS3_ACCESS_EXECUTE
, NFSD_MAY_EXEC
},
648 { NFS3_ACCESS_MODIFY
, NFSD_MAY_WRITE
|NFSD_MAY_LOCAL_ACCESS
},
649 { NFS3_ACCESS_EXTEND
, NFSD_MAY_WRITE
|NFSD_MAY_LOCAL_ACCESS
},
655 nfsd_access(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, u32
*access
, u32
*supported
)
657 struct accessmap
*map
;
658 struct svc_export
*export
;
659 struct dentry
*dentry
;
660 u32 query
, result
= 0, sresult
= 0;
663 error
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_NOP
);
667 export
= fhp
->fh_export
;
668 dentry
= fhp
->fh_dentry
;
670 if (d_is_reg(dentry
))
671 map
= nfs3_regaccess
;
672 else if (d_is_dir(dentry
))
673 map
= nfs3_diraccess
;
675 map
= nfs3_anyaccess
;
679 for (; map
->access
; map
++) {
680 if (map
->access
& query
) {
683 sresult
|= map
->access
;
685 err2
= nfsd_permission(rqstp
, export
, dentry
, map
->how
);
688 result
|= map
->access
;
691 /* the following error codes just mean the access was not allowed,
692 * rather than an error occurred */
696 /* simply don't "or" in the access bit. */
706 *supported
= sresult
;
711 #endif /* CONFIG_NFSD_V3 */
713 int nfsd_open_break_lease(struct inode
*inode
, int access
)
717 if (access
& NFSD_MAY_NOT_BREAK_LEASE
)
719 mode
= (access
& NFSD_MAY_WRITE
) ? O_WRONLY
: O_RDONLY
;
720 return break_lease(inode
, mode
| O_NONBLOCK
);
724 * Open an existing file or directory.
725 * The may_flags argument indicates the type of open (read/write/lock)
726 * and additional flags.
727 * N.B. After this call fhp needs an fh_put
730 __nfsd_open(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, umode_t type
,
731 int may_flags
, struct file
**filp
)
736 int flags
= O_RDONLY
|O_LARGEFILE
;
740 path
.mnt
= fhp
->fh_export
->ex_path
.mnt
;
741 path
.dentry
= fhp
->fh_dentry
;
742 inode
= d_inode(path
.dentry
);
744 /* Disallow write access to files with the append-only bit set
745 * or any access when mandatory locking enabled
748 if (IS_APPEND(inode
) && (may_flags
& NFSD_MAY_WRITE
))
754 host_err
= nfsd_open_break_lease(inode
, may_flags
);
755 if (host_err
) /* NOMEM or WOULDBLOCK */
758 if (may_flags
& NFSD_MAY_WRITE
) {
759 if (may_flags
& NFSD_MAY_READ
)
760 flags
= O_RDWR
|O_LARGEFILE
;
762 flags
= O_WRONLY
|O_LARGEFILE
;
765 file
= dentry_open(&path
, flags
, current_cred());
767 host_err
= PTR_ERR(file
);
771 host_err
= ima_file_check(file
, may_flags
);
777 if (may_flags
& NFSD_MAY_64BIT_COOKIE
)
778 file
->f_mode
|= FMODE_64BITHASH
;
780 file
->f_mode
|= FMODE_32BITHASH
;
784 err
= nfserrno(host_err
);
790 nfsd_open(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, umode_t type
,
791 int may_flags
, struct file
**filp
)
795 validate_process_creds();
797 * If we get here, then the client has already done an "open",
798 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
799 * in case a chmod has now revoked permission.
801 * Arguably we should also allow the owner override for
802 * directories, but we never have and it doesn't seem to have
803 * caused anyone a problem. If we were to change this, note
804 * also that our filldir callbacks would need a variant of
805 * lookup_one_len that doesn't check permissions.
808 may_flags
|= NFSD_MAY_OWNER_OVERRIDE
;
809 err
= fh_verify(rqstp
, fhp
, type
, may_flags
);
811 err
= __nfsd_open(rqstp
, fhp
, type
, may_flags
, filp
);
812 validate_process_creds();
817 nfsd_open_verified(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, umode_t type
,
818 int may_flags
, struct file
**filp
)
822 validate_process_creds();
823 err
= __nfsd_open(rqstp
, fhp
, type
, may_flags
, filp
);
824 validate_process_creds();
829 * Grab and keep cached pages associated with a file in the svc_rqst
830 * so that they can be passed to the network sendmsg/sendpage routines
831 * directly. They will be released after the sending has completed.
834 nfsd_splice_actor(struct pipe_inode_info
*pipe
, struct pipe_buffer
*buf
,
835 struct splice_desc
*sd
)
837 struct svc_rqst
*rqstp
= sd
->u
.data
;
838 struct page
**pp
= rqstp
->rq_next_page
;
839 struct page
*page
= buf
->page
;
841 if (rqstp
->rq_res
.page_len
== 0) {
842 svc_rqst_replace_page(rqstp
, page
);
843 rqstp
->rq_res
.page_base
= buf
->offset
;
844 } else if (page
!= pp
[-1]) {
845 svc_rqst_replace_page(rqstp
, page
);
847 rqstp
->rq_res
.page_len
+= sd
->len
;
852 static int nfsd_direct_splice_actor(struct pipe_inode_info
*pipe
,
853 struct splice_desc
*sd
)
855 return __splice_from_pipe(pipe
, sd
, nfsd_splice_actor
);
858 static u32
nfsd_eof_on_read(struct file
*file
, loff_t offset
, ssize_t len
,
861 if (expected
!= 0 && len
== 0)
863 if (offset
+len
>= i_size_read(file_inode(file
)))
868 static __be32
nfsd_finish_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
869 struct file
*file
, loff_t offset
,
870 unsigned long *count
, u32
*eof
, ssize_t host_err
)
873 nfsd_stats_io_read_add(fhp
->fh_export
, host_err
);
874 *eof
= nfsd_eof_on_read(file
, offset
, host_err
, *count
);
876 fsnotify_access(file
);
877 trace_nfsd_read_io_done(rqstp
, fhp
, offset
, *count
);
880 trace_nfsd_read_err(rqstp
, fhp
, offset
, host_err
);
881 return nfserrno(host_err
);
885 __be32
nfsd_splice_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
886 struct file
*file
, loff_t offset
, unsigned long *count
,
889 struct splice_desc sd
= {
897 trace_nfsd_read_splice(rqstp
, fhp
, offset
, *count
);
898 rqstp
->rq_next_page
= rqstp
->rq_respages
+ 1;
899 host_err
= splice_direct_to_actor(file
, &sd
, nfsd_direct_splice_actor
);
900 return nfsd_finish_read(rqstp
, fhp
, file
, offset
, count
, eof
, host_err
);
903 __be32
nfsd_readv(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
904 struct file
*file
, loff_t offset
,
905 struct kvec
*vec
, int vlen
, unsigned long *count
,
908 struct iov_iter iter
;
909 loff_t ppos
= offset
;
912 trace_nfsd_read_vector(rqstp
, fhp
, offset
, *count
);
913 iov_iter_kvec(&iter
, READ
, vec
, vlen
, *count
);
914 host_err
= vfs_iter_read(file
, &iter
, &ppos
, 0);
915 return nfsd_finish_read(rqstp
, fhp
, file
, offset
, count
, eof
, host_err
);
919 * Gathered writes: If another process is currently writing to the file,
920 * there's a high chance this is another nfsd (triggered by a bulk write
921 * from a client's biod). Rather than syncing the file with each write
922 * request, we sleep for 10 msec.
924 * I don't know if this roughly approximates C. Juszak's idea of
925 * gathered writes, but it's a nice and simple solution (IMHO), and it
928 * Note: we do this only in the NFSv2 case, since v3 and higher have a
929 * better tool (separate unstable writes and commits) for solving this
932 static int wait_for_concurrent_writes(struct file
*file
)
934 struct inode
*inode
= file_inode(file
);
935 static ino_t last_ino
;
936 static dev_t last_dev
;
939 if (atomic_read(&inode
->i_writecount
) > 1
940 || (last_ino
== inode
->i_ino
&& last_dev
== inode
->i_sb
->s_dev
)) {
941 dprintk("nfsd: write defer %d\n", task_pid_nr(current
));
943 dprintk("nfsd: write resume %d\n", task_pid_nr(current
));
946 if (inode
->i_state
& I_DIRTY
) {
947 dprintk("nfsd: write sync %d\n", task_pid_nr(current
));
948 err
= vfs_fsync(file
, 0);
950 last_ino
= inode
->i_ino
;
951 last_dev
= inode
->i_sb
->s_dev
;
956 nfsd_vfs_write(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct nfsd_file
*nf
,
957 loff_t offset
, struct kvec
*vec
, int vlen
,
958 unsigned long *cnt
, int stable
,
961 struct file
*file
= nf
->nf_file
;
962 struct super_block
*sb
= file_inode(file
)->i_sb
;
963 struct svc_export
*exp
;
964 struct iov_iter iter
;
970 unsigned long exp_op_flags
= 0;
971 unsigned int pflags
= current
->flags
;
973 bool restore_flags
= false;
975 trace_nfsd_write_opened(rqstp
, fhp
, offset
, *cnt
);
978 exp_op_flags
= sb
->s_export_op
->flags
;
980 if (test_bit(RQ_LOCAL
, &rqstp
->rq_flags
) &&
981 !(exp_op_flags
& EXPORT_OP_REMOTE_FS
)) {
983 * We want throttling in balance_dirty_pages()
984 * and shrink_inactive_list() to only consider
985 * the backingdev we are writing to, so that nfs to
986 * localhost doesn't cause nfsd to lock up due to all
987 * the client's dirty pages or its congested queue.
989 current
->flags
|= PF_LOCAL_THROTTLE
;
990 restore_flags
= true;
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
, vec
, vlen
, *cnt
);
1003 since
= READ_ONCE(file
->f_wb_err
);
1004 if (flags
& RWF_SYNC
) {
1006 nfsd_copy_boot_verifier(verf
,
1007 net_generic(SVC_NET(rqstp
),
1009 host_err
= vfs_iter_write(file
, &iter
, &pos
, flags
);
1011 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp
),
1015 nfsd_copy_boot_verifier(verf
,
1016 net_generic(SVC_NET(rqstp
),
1018 host_err
= vfs_iter_write(file
, &iter
, &pos
, flags
);
1021 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp
),
1026 nfsd_stats_io_write_add(exp
, *cnt
);
1027 fsnotify_modify(file
);
1028 host_err
= filemap_check_wb_err(file
->f_mapping
, since
);
1032 if (stable
&& use_wgather
) {
1033 host_err
= wait_for_concurrent_writes(file
);
1035 nfsd_reset_boot_verifier(net_generic(SVC_NET(rqstp
),
1040 if (host_err
>= 0) {
1041 trace_nfsd_write_io_done(rqstp
, fhp
, offset
, *cnt
);
1044 trace_nfsd_write_err(rqstp
, fhp
, offset
, host_err
);
1045 nfserr
= nfserrno(host_err
);
1048 current_restore_flags(pflags
, PF_LOCAL_THROTTLE
);
1053 * Read data from a file. count must contain the requested read count
1054 * on entry. On return, *count contains the number of bytes actually read.
1055 * N.B. After this call fhp needs an fh_put
1057 __be32
nfsd_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1058 loff_t offset
, struct kvec
*vec
, int vlen
, unsigned long *count
,
1061 struct nfsd_file
*nf
;
1065 trace_nfsd_read_start(rqstp
, fhp
, offset
, *count
);
1066 err
= nfsd_file_acquire(rqstp
, fhp
, NFSD_MAY_READ
, &nf
);
1071 if (file
->f_op
->splice_read
&& test_bit(RQ_SPLICE_OK
, &rqstp
->rq_flags
))
1072 err
= nfsd_splice_read(rqstp
, fhp
, file
, offset
, count
, eof
);
1074 err
= nfsd_readv(rqstp
, fhp
, file
, offset
, vec
, vlen
, count
, eof
);
1078 trace_nfsd_read_done(rqstp
, fhp
, offset
, *count
);
1084 * Write data to a file.
1085 * The stable flag requests synchronous writes.
1086 * N.B. After this call fhp needs an fh_put
1089 nfsd_write(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, loff_t offset
,
1090 struct kvec
*vec
, int vlen
, unsigned long *cnt
, int stable
,
1093 struct nfsd_file
*nf
;
1096 trace_nfsd_write_start(rqstp
, fhp
, offset
, *cnt
);
1098 err
= nfsd_file_acquire(rqstp
, fhp
, NFSD_MAY_WRITE
, &nf
);
1102 err
= nfsd_vfs_write(rqstp
, fhp
, nf
, offset
, vec
,
1103 vlen
, cnt
, stable
, verf
);
1106 trace_nfsd_write_done(rqstp
, fhp
, offset
, *cnt
);
1110 #ifdef CONFIG_NFSD_V3
1112 * Commit all pending writes to stable storage.
1114 * Note: we only guarantee that data that lies within the range specified
1115 * by the 'offset' and 'count' parameters will be synced.
1117 * Unfortunately we cannot lock the file to make sure we return full WCC
1118 * data to the client, as locking happens lower down in the filesystem.
1121 nfsd_commit(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1122 loff_t offset
, unsigned long count
, __be32
*verf
)
1124 struct nfsd_file
*nf
;
1125 loff_t end
= LLONG_MAX
;
1126 __be32 err
= nfserr_inval
;
1131 end
= offset
+ (loff_t
)count
- 1;
1136 err
= nfsd_file_acquire(rqstp
, fhp
,
1137 NFSD_MAY_WRITE
|NFSD_MAY_NOT_BREAK_LEASE
, &nf
);
1140 if (EX_ISSYNC(fhp
->fh_export
)) {
1141 errseq_t since
= READ_ONCE(nf
->nf_file
->f_wb_err
);
1144 err2
= vfs_fsync_range(nf
->nf_file
, offset
, end
, 0);
1147 nfsd_copy_boot_verifier(verf
, net_generic(nf
->nf_net
,
1149 err2
= filemap_check_wb_err(nf
->nf_file
->f_mapping
,
1151 err
= nfserrno(err2
);
1154 err
= nfserr_notsupp
;
1157 nfsd_reset_boot_verifier(net_generic(nf
->nf_net
,
1159 err
= nfserrno(err2
);
1162 nfsd_copy_boot_verifier(verf
, net_generic(nf
->nf_net
,
1169 #endif /* CONFIG_NFSD_V3 */
1172 nfsd_create_setattr(struct svc_rqst
*rqstp
, struct svc_fh
*resfhp
,
1176 * Mode has already been set earlier in create:
1178 iap
->ia_valid
&= ~ATTR_MODE
;
1180 * Setting uid/gid works only for root. Irix appears to
1181 * send along the gid on create when it tries to implement
1182 * setgid directories via NFS:
1184 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID
))
1185 iap
->ia_valid
&= ~(ATTR_UID
|ATTR_GID
);
1187 return nfsd_setattr(rqstp
, resfhp
, iap
, 0, (time64_t
)0);
1188 /* Callers expect file metadata to be committed here */
1189 return nfserrno(commit_metadata(resfhp
));
1192 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1193 * setting size to 0 may fail for some specific file systems by the permission
1194 * checking which requires WRITE permission but the mode is 000.
1195 * we ignore the resizing(to 0) on the just new created file, since the size is
1196 * 0 after file created.
1198 * call this only after vfs_create() is called.
1201 nfsd_check_ignore_resizing(struct iattr
*iap
)
1203 if ((iap
->ia_valid
& ATTR_SIZE
) && (iap
->ia_size
== 0))
1204 iap
->ia_valid
&= ~ATTR_SIZE
;
1207 /* The parent directory should already be locked: */
1209 nfsd_create_locked(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1210 char *fname
, int flen
, struct iattr
*iap
,
1211 int type
, dev_t rdev
, struct svc_fh
*resfhp
)
1213 struct dentry
*dentry
, *dchild
;
1219 dentry
= fhp
->fh_dentry
;
1220 dirp
= d_inode(dentry
);
1222 dchild
= dget(resfhp
->fh_dentry
);
1223 if (!fhp
->fh_locked
) {
1224 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
1230 err
= nfsd_permission(rqstp
, fhp
->fh_export
, dentry
, NFSD_MAY_CREATE
);
1234 if (!(iap
->ia_valid
& ATTR_MODE
))
1236 iap
->ia_mode
= (iap
->ia_mode
& S_IALLUGO
) | type
;
1238 if (!IS_POSIXACL(dirp
))
1239 iap
->ia_mode
&= ~current_umask();
1245 host_err
= vfs_create(&init_user_ns
, dirp
, dchild
, iap
->ia_mode
, true);
1247 nfsd_check_ignore_resizing(iap
);
1250 host_err
= vfs_mkdir(&init_user_ns
, dirp
, dchild
, iap
->ia_mode
);
1251 if (!host_err
&& unlikely(d_unhashed(dchild
))) {
1253 d
= lookup_one_len(dchild
->d_name
.name
,
1255 dchild
->d_name
.len
);
1257 host_err
= PTR_ERR(d
);
1260 if (unlikely(d_is_negative(d
))) {
1262 err
= nfserr_serverfault
;
1265 dput(resfhp
->fh_dentry
);
1266 resfhp
->fh_dentry
= dget(d
);
1267 err
= fh_update(resfhp
);
1278 host_err
= vfs_mknod(&init_user_ns
, dirp
, dchild
,
1279 iap
->ia_mode
, rdev
);
1282 printk(KERN_WARNING
"nfsd: bad file type %o in nfsd_create\n",
1289 err
= nfsd_create_setattr(rqstp
, resfhp
, iap
);
1292 * nfsd_create_setattr already committed the child. Transactional
1293 * filesystems had a chance to commit changes for both parent and
1294 * child simultaneously making the following commit_metadata a
1297 err2
= nfserrno(commit_metadata(fhp
));
1301 * Update the file handle to get the new inode info.
1304 err
= fh_update(resfhp
);
1310 err
= nfserrno(host_err
);
1315 * Create a filesystem object (regular, directory, special).
1316 * Note that the parent directory is left locked.
1318 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1321 nfsd_create(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1322 char *fname
, int flen
, struct iattr
*iap
,
1323 int type
, dev_t rdev
, struct svc_fh
*resfhp
)
1325 struct dentry
*dentry
, *dchild
= NULL
;
1329 if (isdotent(fname
, flen
))
1330 return nfserr_exist
;
1332 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_NOP
);
1336 dentry
= fhp
->fh_dentry
;
1338 host_err
= fh_want_write(fhp
);
1340 return nfserrno(host_err
);
1342 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1343 dchild
= lookup_one_len(fname
, dentry
, flen
);
1344 host_err
= PTR_ERR(dchild
);
1346 return nfserrno(host_err
);
1347 err
= fh_compose(resfhp
, fhp
->fh_export
, dchild
, fhp
);
1349 * We unconditionally drop our ref to dchild as fh_compose will have
1350 * already grabbed its own ref for it.
1355 return nfsd_create_locked(rqstp
, fhp
, fname
, flen
, iap
, type
,
1359 #ifdef CONFIG_NFSD_V3
1362 * NFSv3 and NFSv4 version of nfsd_create
1365 do_nfsd_create(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1366 char *fname
, int flen
, struct iattr
*iap
,
1367 struct svc_fh
*resfhp
, int createmode
, u32
*verifier
,
1368 bool *truncp
, bool *created
)
1370 struct dentry
*dentry
, *dchild
= NULL
;
1374 __u32 v_mtime
=0, v_atime
=0;
1380 if (isdotent(fname
, flen
))
1382 if (!(iap
->ia_valid
& ATTR_MODE
))
1384 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_EXEC
);
1388 dentry
= fhp
->fh_dentry
;
1389 dirp
= d_inode(dentry
);
1391 host_err
= fh_want_write(fhp
);
1395 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1398 * Compose the response file handle.
1400 dchild
= lookup_one_len(fname
, dentry
, flen
);
1401 host_err
= PTR_ERR(dchild
);
1405 /* If file doesn't exist, check for permissions to create one */
1406 if (d_really_is_negative(dchild
)) {
1407 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1412 err
= fh_compose(resfhp
, fhp
->fh_export
, dchild
, fhp
);
1416 if (nfsd_create_is_exclusive(createmode
)) {
1417 /* solaris7 gets confused (bugid 4218508) if these have
1418 * the high bit set, so just clear the high bits. If this is
1419 * ever changed to use different attrs for storing the
1420 * verifier, then do_open_lookup() will also need to be fixed
1423 v_mtime
= verifier
[0]&0x7fffffff;
1424 v_atime
= verifier
[1]&0x7fffffff;
1427 if (d_really_is_positive(dchild
)) {
1430 switch (createmode
) {
1431 case NFS3_CREATE_UNCHECKED
:
1432 if (! d_is_reg(dchild
))
1435 /* in nfsv4, we need to treat this case a little
1436 * differently. we don't want to truncate the
1437 * file now; this would be wrong if the OPEN
1438 * fails for some other reason. furthermore,
1439 * if the size is nonzero, we should ignore it
1440 * according to spec!
1442 *truncp
= (iap
->ia_valid
& ATTR_SIZE
) && !iap
->ia_size
;
1445 iap
->ia_valid
&= ATTR_SIZE
;
1449 case NFS3_CREATE_EXCLUSIVE
:
1450 if ( d_inode(dchild
)->i_mtime
.tv_sec
== v_mtime
1451 && d_inode(dchild
)->i_atime
.tv_sec
== v_atime
1452 && d_inode(dchild
)->i_size
== 0 ) {
1458 case NFS4_CREATE_EXCLUSIVE4_1
:
1459 if ( d_inode(dchild
)->i_mtime
.tv_sec
== v_mtime
1460 && d_inode(dchild
)->i_atime
.tv_sec
== v_atime
1461 && d_inode(dchild
)->i_size
== 0 ) {
1467 case NFS3_CREATE_GUARDED
:
1474 if (!IS_POSIXACL(dirp
))
1475 iap
->ia_mode
&= ~current_umask();
1477 host_err
= vfs_create(&init_user_ns
, dirp
, dchild
, iap
->ia_mode
, true);
1485 nfsd_check_ignore_resizing(iap
);
1487 if (nfsd_create_is_exclusive(createmode
)) {
1488 /* Cram the verifier into atime/mtime */
1489 iap
->ia_valid
= ATTR_MTIME
|ATTR_ATIME
1490 | ATTR_MTIME_SET
|ATTR_ATIME_SET
;
1491 /* XXX someone who knows this better please fix it for nsec */
1492 iap
->ia_mtime
.tv_sec
= v_mtime
;
1493 iap
->ia_atime
.tv_sec
= v_atime
;
1494 iap
->ia_mtime
.tv_nsec
= 0;
1495 iap
->ia_atime
.tv_nsec
= 0;
1499 err
= nfsd_create_setattr(rqstp
, resfhp
, iap
);
1502 * nfsd_create_setattr already committed the child
1503 * (and possibly also the parent).
1506 err
= nfserrno(commit_metadata(fhp
));
1509 * Update the filehandle to get the new inode info.
1512 err
= fh_update(resfhp
);
1516 if (dchild
&& !IS_ERR(dchild
))
1522 err
= nfserrno(host_err
);
1525 #endif /* CONFIG_NFSD_V3 */
1528 * Read a symlink. On entry, *lenp must contain the maximum path length that
1529 * fits into the buffer. On return, it contains the true length.
1530 * N.B. After this call fhp needs an fh_put
1533 nfsd_readlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *buf
, int *lenp
)
1538 DEFINE_DELAYED_CALL(done
);
1541 err
= fh_verify(rqstp
, fhp
, S_IFLNK
, NFSD_MAY_NOP
);
1545 path
.mnt
= fhp
->fh_export
->ex_path
.mnt
;
1546 path
.dentry
= fhp
->fh_dentry
;
1548 if (unlikely(!d_is_symlink(path
.dentry
)))
1549 return nfserr_inval
;
1553 link
= vfs_get_link(path
.dentry
, &done
);
1555 return nfserrno(PTR_ERR(link
));
1560 memcpy(buf
, link
, *lenp
);
1561 do_delayed_call(&done
);
1566 * Create a symlink and look up its inode
1567 * N.B. After this call _both_ fhp and resfhp need an fh_put
1570 nfsd_symlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1571 char *fname
, int flen
,
1573 struct svc_fh
*resfhp
)
1575 struct dentry
*dentry
, *dnew
;
1580 if (!flen
|| path
[0] == '\0')
1583 if (isdotent(fname
, flen
))
1586 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1590 host_err
= fh_want_write(fhp
);
1595 dentry
= fhp
->fh_dentry
;
1596 dnew
= lookup_one_len(fname
, dentry
, flen
);
1597 host_err
= PTR_ERR(dnew
);
1601 host_err
= vfs_symlink(&init_user_ns
, d_inode(dentry
), dnew
, path
);
1602 err
= nfserrno(host_err
);
1605 err
= nfserrno(commit_metadata(fhp
));
1609 cerr
= fh_compose(resfhp
, fhp
->fh_export
, dnew
, fhp
);
1611 if (err
==0) err
= cerr
;
1616 err
= nfserrno(host_err
);
1622 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1625 nfsd_link(struct svc_rqst
*rqstp
, struct svc_fh
*ffhp
,
1626 char *name
, int len
, struct svc_fh
*tfhp
)
1628 struct dentry
*ddir
, *dnew
, *dold
;
1633 err
= fh_verify(rqstp
, ffhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1636 err
= fh_verify(rqstp
, tfhp
, 0, NFSD_MAY_NOP
);
1640 if (d_is_dir(tfhp
->fh_dentry
))
1646 if (isdotent(name
, len
))
1649 host_err
= fh_want_write(tfhp
);
1651 err
= nfserrno(host_err
);
1655 fh_lock_nested(ffhp
, I_MUTEX_PARENT
);
1656 ddir
= ffhp
->fh_dentry
;
1657 dirp
= d_inode(ddir
);
1659 dnew
= lookup_one_len(name
, ddir
, len
);
1660 host_err
= PTR_ERR(dnew
);
1664 dold
= tfhp
->fh_dentry
;
1667 if (d_really_is_negative(dold
))
1669 host_err
= vfs_link(dold
, &init_user_ns
, dirp
, dnew
, NULL
);
1672 err
= nfserrno(commit_metadata(ffhp
));
1674 err
= nfserrno(commit_metadata(tfhp
));
1676 if (host_err
== -EXDEV
&& rqstp
->rq_vers
== 2)
1679 err
= nfserrno(host_err
);
1685 fh_drop_write(tfhp
);
1690 err
= nfserrno(host_err
);
1695 nfsd_close_cached_files(struct dentry
*dentry
)
1697 struct inode
*inode
= d_inode(dentry
);
1699 if (inode
&& S_ISREG(inode
->i_mode
))
1700 nfsd_file_close_inode_sync(inode
);
1704 nfsd_has_cached_files(struct dentry
*dentry
)
1707 struct inode
*inode
= d_inode(dentry
);
1709 if (inode
&& S_ISREG(inode
->i_mode
))
1710 ret
= nfsd_file_is_cached(inode
);
1716 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1719 nfsd_rename(struct svc_rqst
*rqstp
, struct svc_fh
*ffhp
, char *fname
, int flen
,
1720 struct svc_fh
*tfhp
, char *tname
, int tlen
)
1722 struct dentry
*fdentry
, *tdentry
, *odentry
, *ndentry
, *trap
;
1723 struct inode
*fdir
, *tdir
;
1726 bool close_cached
= false;
1728 err
= fh_verify(rqstp
, ffhp
, S_IFDIR
, NFSD_MAY_REMOVE
);
1731 err
= fh_verify(rqstp
, tfhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1735 fdentry
= ffhp
->fh_dentry
;
1736 fdir
= d_inode(fdentry
);
1738 tdentry
= tfhp
->fh_dentry
;
1739 tdir
= d_inode(tdentry
);
1742 if (!flen
|| isdotent(fname
, flen
) || !tlen
|| isdotent(tname
, tlen
))
1746 host_err
= fh_want_write(ffhp
);
1748 err
= nfserrno(host_err
);
1752 /* cannot use fh_lock as we need deadlock protective ordering
1753 * so do it by hand */
1754 trap
= lock_rename(tdentry
, fdentry
);
1755 ffhp
->fh_locked
= tfhp
->fh_locked
= true;
1759 odentry
= lookup_one_len(fname
, fdentry
, flen
);
1760 host_err
= PTR_ERR(odentry
);
1761 if (IS_ERR(odentry
))
1765 if (d_really_is_negative(odentry
))
1768 if (odentry
== trap
)
1771 ndentry
= lookup_one_len(tname
, tdentry
, tlen
);
1772 host_err
= PTR_ERR(ndentry
);
1773 if (IS_ERR(ndentry
))
1775 host_err
= -ENOTEMPTY
;
1776 if (ndentry
== trap
)
1780 if (ffhp
->fh_export
->ex_path
.mnt
!= tfhp
->fh_export
->ex_path
.mnt
)
1782 if (ffhp
->fh_export
->ex_path
.dentry
!= tfhp
->fh_export
->ex_path
.dentry
)
1785 if ((ndentry
->d_sb
->s_export_op
->flags
& EXPORT_OP_CLOSE_BEFORE_UNLINK
) &&
1786 nfsd_has_cached_files(ndentry
)) {
1787 close_cached
= true;
1790 struct renamedata rd
= {
1791 .old_mnt_userns
= &init_user_ns
,
1793 .old_dentry
= odentry
,
1794 .new_mnt_userns
= &init_user_ns
,
1796 .new_dentry
= ndentry
,
1798 host_err
= vfs_rename(&rd
);
1800 host_err
= commit_metadata(tfhp
);
1802 host_err
= commit_metadata(ffhp
);
1810 err
= nfserrno(host_err
);
1812 * We cannot rely on fh_unlock on the two filehandles,
1813 * as that would do the wrong thing if the two directories
1814 * were the same, so again we do it by hand.
1816 if (!close_cached
) {
1817 fill_post_wcc(ffhp
);
1818 fill_post_wcc(tfhp
);
1820 unlock_rename(tdentry
, fdentry
);
1821 ffhp
->fh_locked
= tfhp
->fh_locked
= false;
1822 fh_drop_write(ffhp
);
1825 * If the target dentry has cached open files, then we need to try to
1826 * close them prior to doing the rename. Flushing delayed fput
1827 * shouldn't be done with locks held however, so we delay it until this
1828 * point and then reattempt the whole shebang.
1831 close_cached
= false;
1832 nfsd_close_cached_files(ndentry
);
1841 * Unlink a file or directory
1842 * N.B. After this call fhp needs an fh_put
1845 nfsd_unlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, int type
,
1846 char *fname
, int flen
)
1848 struct dentry
*dentry
, *rdentry
;
1850 struct inode
*rinode
;
1855 if (!flen
|| isdotent(fname
, flen
))
1857 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_REMOVE
);
1861 host_err
= fh_want_write(fhp
);
1865 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1866 dentry
= fhp
->fh_dentry
;
1867 dirp
= d_inode(dentry
);
1869 rdentry
= lookup_one_len(fname
, dentry
, flen
);
1870 host_err
= PTR_ERR(rdentry
);
1871 if (IS_ERR(rdentry
))
1872 goto out_drop_write
;
1874 if (d_really_is_negative(rdentry
)) {
1877 goto out_drop_write
;
1879 rinode
= d_inode(rdentry
);
1883 type
= d_inode(rdentry
)->i_mode
& S_IFMT
;
1885 if (type
!= S_IFDIR
) {
1886 if (rdentry
->d_sb
->s_export_op
->flags
& EXPORT_OP_CLOSE_BEFORE_UNLINK
)
1887 nfsd_close_cached_files(rdentry
);
1888 host_err
= vfs_unlink(&init_user_ns
, dirp
, rdentry
, NULL
);
1890 host_err
= vfs_rmdir(&init_user_ns
, dirp
, rdentry
);
1895 host_err
= commit_metadata(fhp
);
1897 iput(rinode
); /* truncate the inode here */
1902 if (host_err
== -EBUSY
) {
1903 /* name is mounted-on. There is no perfect
1906 if (nfsd_v4client(rqstp
))
1907 err
= nfserr_file_open
;
1911 err
= nfserrno(host_err
);
1918 * We do this buffering because we must not call back into the file
1919 * system's ->lookup() method from the filldir callback. That may well
1920 * deadlock a number of file systems.
1922 * This is based heavily on the implementation of same in XFS.
1924 struct buffered_dirent
{
1928 unsigned int d_type
;
1932 struct readdir_data
{
1933 struct dir_context ctx
;
1939 static int nfsd_buffered_filldir(struct dir_context
*ctx
, const char *name
,
1940 int namlen
, loff_t offset
, u64 ino
,
1941 unsigned int d_type
)
1943 struct readdir_data
*buf
=
1944 container_of(ctx
, struct readdir_data
, ctx
);
1945 struct buffered_dirent
*de
= (void *)(buf
->dirent
+ buf
->used
);
1946 unsigned int reclen
;
1948 reclen
= ALIGN(sizeof(struct buffered_dirent
) + namlen
, sizeof(u64
));
1949 if (buf
->used
+ reclen
> PAGE_SIZE
) {
1954 de
->namlen
= namlen
;
1955 de
->offset
= offset
;
1957 de
->d_type
= d_type
;
1958 memcpy(de
->name
, name
, namlen
);
1959 buf
->used
+= reclen
;
1964 static __be32
nfsd_buffered_readdir(struct file
*file
, struct svc_fh
*fhp
,
1965 nfsd_filldir_t func
, struct readdir_cd
*cdp
,
1968 struct buffered_dirent
*de
;
1972 struct readdir_data buf
= {
1973 .ctx
.actor
= nfsd_buffered_filldir
,
1974 .dirent
= (void *)__get_free_page(GFP_KERNEL
)
1978 return nfserrno(-ENOMEM
);
1983 unsigned int reclen
;
1985 cdp
->err
= nfserr_eof
; /* will be cleared on successful read */
1989 host_err
= iterate_dir(file
, &buf
.ctx
);
2001 de
= (struct buffered_dirent
*)buf
.dirent
;
2003 offset
= de
->offset
;
2005 if (func(cdp
, de
->name
, de
->namlen
, de
->offset
,
2006 de
->ino
, de
->d_type
))
2009 if (cdp
->err
!= nfs_ok
)
2012 trace_nfsd_dirent(fhp
, de
->ino
, de
->name
, de
->namlen
);
2014 reclen
= ALIGN(sizeof(*de
) + de
->namlen
,
2017 de
= (struct buffered_dirent
*)((char *)de
+ reclen
);
2019 if (size
> 0) /* We bailed out early */
2022 offset
= vfs_llseek(file
, 0, SEEK_CUR
);
2025 free_page((unsigned long)(buf
.dirent
));
2028 return nfserrno(host_err
);
2035 * Read entries from a directory.
2036 * The NFSv3/4 verifier we ignore for now.
2039 nfsd_readdir(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, loff_t
*offsetp
,
2040 struct readdir_cd
*cdp
, nfsd_filldir_t func
)
2044 loff_t offset
= *offsetp
;
2045 int may_flags
= NFSD_MAY_READ
;
2047 /* NFSv2 only supports 32 bit cookies */
2048 if (rqstp
->rq_vers
> 2)
2049 may_flags
|= NFSD_MAY_64BIT_COOKIE
;
2051 err
= nfsd_open(rqstp
, fhp
, S_IFDIR
, may_flags
, &file
);
2055 offset
= vfs_llseek(file
, offset
, SEEK_SET
);
2057 err
= nfserrno((int)offset
);
2061 err
= nfsd_buffered_readdir(file
, fhp
, func
, cdp
, offsetp
);
2063 if (err
== nfserr_eof
|| err
== nfserr_toosmall
)
2064 err
= nfs_ok
; /* can still be found in ->err */
2072 * Get file system stats
2073 * N.B. After this call fhp needs an fh_put
2076 nfsd_statfs(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct kstatfs
*stat
, int access
)
2080 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_NOP
| access
);
2082 struct path path
= {
2083 .mnt
= fhp
->fh_export
->ex_path
.mnt
,
2084 .dentry
= fhp
->fh_dentry
,
2086 if (vfs_statfs(&path
, stat
))
2092 static int exp_rdonly(struct svc_rqst
*rqstp
, struct svc_export
*exp
)
2094 return nfsexp_flags(rqstp
, exp
) & NFSEXP_READONLY
;
2097 #ifdef CONFIG_NFSD_V4
2099 * Helper function to translate error numbers. In the case of xattr operations,
2100 * some error codes need to be translated outside of the standard translations.
2102 * ENODATA needs to be translated to nfserr_noxattr.
2103 * E2BIG to nfserr_xattr2big.
2105 * Additionally, vfs_listxattr can return -ERANGE. This means that the
2106 * file has too many extended attributes to retrieve inside an
2107 * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
2108 * filesystems will allow the adding of extended attributes until they hit
2109 * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
2110 * So, at that point, the attributes are present and valid, but can't
2111 * be retrieved using listxattr, since the upper level xattr code enforces
2112 * the XATTR_LIST_MAX limit.
2114 * This bug means that we need to deal with listxattr returning -ERANGE. The
2115 * best mapping is to return TOOSMALL.
2118 nfsd_xattr_errno(int err
)
2122 return nfserr_noxattr
;
2124 return nfserr_xattr2big
;
2126 return nfserr_toosmall
;
2128 return nfserrno(err
);
2132 * Retrieve the specified user extended attribute. To avoid always
2133 * having to allocate the maximum size (since we are not getting
2134 * a maximum size from the RPC), do a probe + alloc. Hold a reader
2135 * lock on i_rwsem to prevent the extended attribute from changing
2136 * size while we're doing this.
2139 nfsd_getxattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *name
,
2140 void **bufp
, int *lenp
)
2145 struct inode
*inode
;
2146 struct dentry
*dentry
;
2148 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_READ
);
2153 dentry
= fhp
->fh_dentry
;
2154 inode
= d_inode(dentry
);
2156 inode_lock_shared(inode
);
2158 len
= vfs_getxattr(&init_user_ns
, dentry
, name
, NULL
, 0);
2161 * Zero-length attribute, just return.
2170 err
= nfsd_xattr_errno(len
);
2175 err
= nfserr_toosmall
;
2179 buf
= kvmalloc(len
, GFP_KERNEL
| GFP_NOFS
);
2181 err
= nfserr_jukebox
;
2185 len
= vfs_getxattr(&init_user_ns
, dentry
, name
, buf
, len
);
2189 err
= nfsd_xattr_errno(len
);
2196 inode_unlock_shared(inode
);
2202 * Retrieve the xattr names. Since we can't know how many are
2203 * user extended attributes, we must get all attributes here,
2204 * and have the XDR encode filter out the "user." ones.
2206 * While this could always just allocate an XATTR_LIST_MAX
2207 * buffer, that's a waste, so do a probe + allocate. To
2208 * avoid any changes between the probe and allocate, wrap
2209 * this in inode_lock.
2212 nfsd_listxattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char **bufp
,
2218 struct inode
*inode
;
2219 struct dentry
*dentry
;
2221 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_READ
);
2225 dentry
= fhp
->fh_dentry
;
2226 inode
= d_inode(dentry
);
2229 inode_lock_shared(inode
);
2231 len
= vfs_listxattr(dentry
, NULL
, 0);
2233 err
= nfsd_xattr_errno(len
);
2237 if (len
> XATTR_LIST_MAX
) {
2238 err
= nfserr_xattr2big
;
2243 * We're holding i_rwsem - use GFP_NOFS.
2245 buf
= kvmalloc(len
, GFP_KERNEL
| GFP_NOFS
);
2247 err
= nfserr_jukebox
;
2251 len
= vfs_listxattr(dentry
, buf
, len
);
2254 err
= nfsd_xattr_errno(len
);
2263 inode_unlock_shared(inode
);
2269 * Removexattr and setxattr need to call fh_lock to both lock the inode
2270 * and set the change attribute. Since the top-level vfs_removexattr
2271 * and vfs_setxattr calls already do their own inode_lock calls, call
2272 * the _locked variant. Pass in a NULL pointer for delegated_inode,
2273 * and let the client deal with NFS4ERR_DELAY (same as with e.g.
2274 * setattr and remove).
2277 nfsd_removexattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *name
)
2282 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_WRITE
);
2286 ret
= fh_want_write(fhp
);
2288 return nfserrno(ret
);
2292 ret
= __vfs_removexattr_locked(&init_user_ns
, fhp
->fh_dentry
,
2298 return nfsd_xattr_errno(ret
);
2302 nfsd_setxattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *name
,
2303 void *buf
, u32 len
, u32 flags
)
2308 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_WRITE
);
2312 ret
= fh_want_write(fhp
);
2314 return nfserrno(ret
);
2317 ret
= __vfs_setxattr_locked(&init_user_ns
, fhp
->fh_dentry
, name
, buf
,
2323 return nfsd_xattr_errno(ret
);
2328 * Check for a user's access permissions to this inode.
2331 nfsd_permission(struct svc_rqst
*rqstp
, struct svc_export
*exp
,
2332 struct dentry
*dentry
, int acc
)
2334 struct inode
*inode
= d_inode(dentry
);
2337 if ((acc
& NFSD_MAY_MASK
) == NFSD_MAY_NOP
)
2340 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2342 (acc
& NFSD_MAY_READ
)? " read" : "",
2343 (acc
& NFSD_MAY_WRITE
)? " write" : "",
2344 (acc
& NFSD_MAY_EXEC
)? " exec" : "",
2345 (acc
& NFSD_MAY_SATTR
)? " sattr" : "",
2346 (acc
& NFSD_MAY_TRUNC
)? " trunc" : "",
2347 (acc
& NFSD_MAY_LOCK
)? " lock" : "",
2348 (acc
& NFSD_MAY_OWNER_OVERRIDE
)? " owneroverride" : "",
2350 IS_IMMUTABLE(inode
)? " immut" : "",
2351 IS_APPEND(inode
)? " append" : "",
2352 __mnt_is_readonly(exp
->ex_path
.mnt
)? " ro" : "");
2353 dprintk(" owner %d/%d user %d/%d\n",
2354 inode
->i_uid
, inode
->i_gid
, current_fsuid(), current_fsgid());
2357 /* Normally we reject any write/sattr etc access on a read-only file
2358 * system. But if it is IRIX doing check on write-access for a
2359 * device special file, we ignore rofs.
2361 if (!(acc
& NFSD_MAY_LOCAL_ACCESS
))
2362 if (acc
& (NFSD_MAY_WRITE
| NFSD_MAY_SATTR
| NFSD_MAY_TRUNC
)) {
2363 if (exp_rdonly(rqstp
, exp
) ||
2364 __mnt_is_readonly(exp
->ex_path
.mnt
))
2366 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode
))
2369 if ((acc
& NFSD_MAY_TRUNC
) && IS_APPEND(inode
))
2372 if (acc
& NFSD_MAY_LOCK
) {
2373 /* If we cannot rely on authentication in NLM requests,
2374 * just allow locks, otherwise require read permission, or
2377 if (exp
->ex_flags
& NFSEXP_NOAUTHNLM
)
2380 acc
= NFSD_MAY_READ
| NFSD_MAY_OWNER_OVERRIDE
;
2383 * The file owner always gets access permission for accesses that
2384 * would normally be checked at open time. This is to make
2385 * file access work even when the client has done a fchmod(fd, 0).
2387 * However, `cp foo bar' should fail nevertheless when bar is
2388 * readonly. A sensible way to do this might be to reject all
2389 * attempts to truncate a read-only file, because a creat() call
2390 * always implies file truncation.
2391 * ... but this isn't really fair. A process may reasonably call
2392 * ftruncate on an open file descriptor on a file with perm 000.
2393 * We must trust the client to do permission checking - using "ACCESS"
2396 if ((acc
& NFSD_MAY_OWNER_OVERRIDE
) &&
2397 uid_eq(inode
->i_uid
, current_fsuid()))
2400 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2401 err
= inode_permission(&init_user_ns
, inode
,
2402 acc
& (MAY_READ
| MAY_WRITE
| MAY_EXEC
));
2404 /* Allow read access to binaries even when mode 111 */
2405 if (err
== -EACCES
&& S_ISREG(inode
->i_mode
) &&
2406 (acc
== (NFSD_MAY_READ
| NFSD_MAY_OWNER_OVERRIDE
) ||
2407 acc
== (NFSD_MAY_READ
| NFSD_MAY_READ_IF_EXEC
)))
2408 err
= inode_permission(&init_user_ns
, inode
, MAY_EXEC
);
2410 return err
? nfserrno(err
) : 0;