1 // SPDX-License-Identifier: GPL-2.0
3 * File operations used by nfsd. Some of these have been ripped from
4 * other parts of the kernel because they weren't exported, others
5 * are partial duplicates with added or changed functionality.
7 * Note that several functions dget() the dentry upon which they want
8 * to act, most notably those that create directory entries. Response
9 * dentry's are dput()'d if necessary in the release callback.
10 * So if you notice code paths that apparently fail to dput() the
11 * dentry, don't worry--they have been taken care of.
13 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
14 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
18 #include <linux/file.h>
19 #include <linux/splice.h>
20 #include <linux/falloc.h>
21 #include <linux/fcntl.h>
22 #include <linux/namei.h>
23 #include <linux/delay.h>
24 #include <linux/fsnotify.h>
25 #include <linux/posix_acl_xattr.h>
26 #include <linux/xattr.h>
27 #include <linux/jhash.h>
28 #include <linux/ima.h>
29 #include <linux/slab.h>
30 #include <linux/uaccess.h>
31 #include <linux/exportfs.h>
32 #include <linux/writeback.h>
33 #include <linux/security.h>
37 #endif /* CONFIG_NFSD_V3 */
40 #include "../internal.h"
43 #endif /* CONFIG_NFSD_V4 */
49 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
53 * This is a cache of readahead params that help us choose the proper
54 * readahead strategy. Initially, we set all readahead parameters to 0
55 * and let the VFS handle things.
56 * If you increase the number of cached files very much, you'll need to
57 * add a hash table here.
60 struct raparms
*p_next
;
65 struct file_ra_state p_ra
;
66 unsigned int p_hindex
;
69 struct raparm_hbucket
{
70 struct raparms
*pb_head
;
72 } ____cacheline_aligned_in_smp
;
74 #define RAPARM_HASH_BITS 4
75 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS)
76 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1)
77 static struct raparm_hbucket raparm_hash
[RAPARM_HASH_SIZE
];
80 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
82 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
83 * or nfs_ok having possibly changed *dpp and *expp
86 nfsd_cross_mnt(struct svc_rqst
*rqstp
, struct dentry
**dpp
,
87 struct svc_export
**expp
)
89 struct svc_export
*exp
= *expp
, *exp2
= NULL
;
90 struct dentry
*dentry
= *dpp
;
91 struct path path
= {.mnt
= mntget(exp
->ex_path
.mnt
),
92 .dentry
= dget(dentry
)};
95 err
= follow_down(&path
);
98 if (path
.mnt
== exp
->ex_path
.mnt
&& path
.dentry
== dentry
&&
99 nfsd_mountpoint(dentry
, exp
) == 2) {
100 /* This is only a mountpoint in some other namespace */
105 exp2
= rqst_exp_get_by_name(rqstp
, &path
);
109 * We normally allow NFS clients to continue
110 * "underneath" a mountpoint that is not exported.
111 * The exception is V4ROOT, where no traversal is ever
112 * allowed without an explicit export of the new
115 if (err
== -ENOENT
&& !(exp
->ex_flags
& NFSEXP_V4ROOT
))
120 if (nfsd_v4client(rqstp
) ||
121 (exp
->ex_flags
& NFSEXP_CROSSMOUNT
) || EX_NOHIDE(exp2
)) {
122 /* successfully crossed mount point */
124 * This is subtle: path.dentry is *not* on path.mnt
125 * at this point. The only reason we are safe is that
126 * original mnt is pinned down by exp, so we should
127 * put path *before* putting exp
130 path
.dentry
= dentry
;
140 static void follow_to_parent(struct path
*path
)
144 while (path
->dentry
== path
->mnt
->mnt_root
&& follow_up(path
))
146 dp
= dget_parent(path
->dentry
);
151 static int nfsd_lookup_parent(struct svc_rqst
*rqstp
, struct dentry
*dparent
, struct svc_export
**exp
, struct dentry
**dentryp
)
153 struct svc_export
*exp2
;
154 struct path path
= {.mnt
= mntget((*exp
)->ex_path
.mnt
),
155 .dentry
= dget(dparent
)};
157 follow_to_parent(&path
);
159 exp2
= rqst_exp_parent(rqstp
, &path
);
160 if (PTR_ERR(exp2
) == -ENOENT
) {
161 *dentryp
= dget(dparent
);
162 } else if (IS_ERR(exp2
)) {
164 return PTR_ERR(exp2
);
166 *dentryp
= dget(path
.dentry
);
175 * For nfsd purposes, we treat V4ROOT exports as though there was an
176 * export at *every* directory.
178 * '1' if this dentry *must* be an export point,
179 * '2' if it might be, if there is really a mount here, and
180 * '0' if there is no chance of an export point here.
182 int nfsd_mountpoint(struct dentry
*dentry
, struct svc_export
*exp
)
184 if (!d_inode(dentry
))
186 if (exp
->ex_flags
& NFSEXP_V4ROOT
)
188 if (nfsd4_is_junction(dentry
))
190 if (d_mountpoint(dentry
))
192 * Might only be a mountpoint in a different namespace,
193 * but we need to check.
200 nfsd_lookup_dentry(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
201 const char *name
, unsigned int len
,
202 struct svc_export
**exp_ret
, struct dentry
**dentry_ret
)
204 struct svc_export
*exp
;
205 struct dentry
*dparent
;
206 struct dentry
*dentry
;
209 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp
), len
,name
);
211 dparent
= fhp
->fh_dentry
;
212 exp
= exp_get(fhp
->fh_export
);
214 /* Lookup the name, but don't follow links */
215 if (isdotent(name
, len
)) {
217 dentry
= dget(dparent
);
218 else if (dparent
!= exp
->ex_path
.dentry
)
219 dentry
= dget_parent(dparent
);
220 else if (!EX_NOHIDE(exp
) && !nfsd_v4client(rqstp
))
221 dentry
= dget(dparent
); /* .. == . just like at / */
223 /* checking mountpoint crossing is very different when stepping up */
224 host_err
= nfsd_lookup_parent(rqstp
, dparent
, &exp
, &dentry
);
230 * In the nfsd4_open() case, this may be held across
231 * subsequent open and delegation acquisition which may
232 * need to take the child's i_mutex:
234 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
235 dentry
= lookup_one_len(name
, dparent
, len
);
236 host_err
= PTR_ERR(dentry
);
239 if (nfsd_mountpoint(dentry
, exp
)) {
241 * We don't need the i_mutex after all. It's
242 * still possible we could open this (regular
243 * files can be mountpoints too), but the
244 * i_mutex is just there to prevent renames of
245 * something that we might be about to delegate,
246 * and a mountpoint won't be renamed:
249 if ((host_err
= nfsd_cross_mnt(rqstp
, &dentry
, &exp
))) {
255 *dentry_ret
= dentry
;
261 return nfserrno(host_err
);
265 * Look up one component of a pathname.
266 * N.B. After this call _both_ fhp and resfh need an fh_put
268 * If the lookup would cross a mountpoint, and the mounted filesystem
269 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
270 * accepted as it stands and the mounted directory is
271 * returned. Otherwise the covered directory is returned.
272 * NOTE: this mountpoint crossing is not supported properly by all
273 * clients and is explicitly disallowed for NFSv3
274 * NeilBrown <neilb@cse.unsw.edu.au>
277 nfsd_lookup(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, const char *name
,
278 unsigned int len
, struct svc_fh
*resfh
)
280 struct svc_export
*exp
;
281 struct dentry
*dentry
;
284 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_EXEC
);
287 err
= nfsd_lookup_dentry(rqstp
, fhp
, name
, len
, &exp
, &dentry
);
290 err
= check_nfsd_access(exp
, rqstp
);
294 * Note: we compose the file handle now, but as the
295 * dentry may be negative, it may need to be updated.
297 err
= fh_compose(resfh
, exp
, dentry
, fhp
);
298 if (!err
&& d_really_is_negative(dentry
))
307 * Commit metadata changes to stable storage.
310 commit_metadata(struct svc_fh
*fhp
)
312 struct inode
*inode
= d_inode(fhp
->fh_dentry
);
313 const struct export_operations
*export_ops
= inode
->i_sb
->s_export_op
;
315 if (!EX_ISSYNC(fhp
->fh_export
))
318 if (export_ops
->commit_metadata
)
319 return export_ops
->commit_metadata(inode
);
320 return sync_inode_metadata(inode
, 1);
324 * Go over the attributes and take care of the small differences between
325 * NFS semantics and what Linux expects.
328 nfsd_sanitize_attrs(struct inode
*inode
, struct iattr
*iap
)
330 /* sanitize the mode change */
331 if (iap
->ia_valid
& ATTR_MODE
) {
332 iap
->ia_mode
&= S_IALLUGO
;
333 iap
->ia_mode
|= (inode
->i_mode
& ~S_IALLUGO
);
336 /* Revoke setuid/setgid on chown */
337 if (!S_ISDIR(inode
->i_mode
) &&
338 ((iap
->ia_valid
& ATTR_UID
) || (iap
->ia_valid
& ATTR_GID
))) {
339 iap
->ia_valid
|= ATTR_KILL_PRIV
;
340 if (iap
->ia_valid
& ATTR_MODE
) {
341 /* we're setting mode too, just clear the s*id bits */
342 iap
->ia_mode
&= ~S_ISUID
;
343 if (iap
->ia_mode
& S_IXGRP
)
344 iap
->ia_mode
&= ~S_ISGID
;
346 /* set ATTR_KILL_* bits and let VFS handle it */
347 iap
->ia_valid
|= (ATTR_KILL_SUID
| ATTR_KILL_SGID
);
353 nfsd_get_write_access(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
356 struct inode
*inode
= d_inode(fhp
->fh_dentry
);
359 if (iap
->ia_size
< inode
->i_size
) {
362 err
= nfsd_permission(rqstp
, fhp
->fh_export
, fhp
->fh_dentry
,
363 NFSD_MAY_TRUNC
| NFSD_MAY_OWNER_OVERRIDE
);
368 host_err
= get_write_access(inode
);
372 host_err
= locks_verify_truncate(inode
, NULL
, iap
->ia_size
);
374 goto out_put_write_access
;
377 out_put_write_access
:
378 put_write_access(inode
);
380 return nfserrno(host_err
);
384 * Set various file attributes. After this call fhp needs an fh_put.
387 nfsd_setattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct iattr
*iap
,
388 int check_guard
, time_t guardtime
)
390 struct dentry
*dentry
;
392 int accmode
= NFSD_MAY_SATTR
;
396 bool get_write_count
;
397 bool size_change
= (iap
->ia_valid
& ATTR_SIZE
);
399 if (iap
->ia_valid
& (ATTR_ATIME
| ATTR_MTIME
| ATTR_SIZE
))
400 accmode
|= NFSD_MAY_WRITE
|NFSD_MAY_OWNER_OVERRIDE
;
401 if (iap
->ia_valid
& ATTR_SIZE
)
404 /* Callers that do fh_verify should do the fh_want_write: */
405 get_write_count
= !fhp
->fh_dentry
;
408 err
= fh_verify(rqstp
, fhp
, ftype
, accmode
);
411 if (get_write_count
) {
412 host_err
= fh_want_write(fhp
);
417 dentry
= fhp
->fh_dentry
;
418 inode
= d_inode(dentry
);
420 /* Ignore any mode updates on symlinks */
421 if (S_ISLNK(inode
->i_mode
))
422 iap
->ia_valid
&= ~ATTR_MODE
;
427 nfsd_sanitize_attrs(inode
, iap
);
429 if (check_guard
&& guardtime
!= inode
->i_ctime
.tv_sec
)
430 return nfserr_notsync
;
433 * The size case is special, it changes the file in addition to the
434 * attributes, and file systems don't expect it to be mixed with
435 * "random" attribute changes. We thus split out the size change
436 * into a separate call to ->setattr, and do the rest as a separate
440 err
= nfsd_get_write_access(rqstp
, fhp
, iap
);
448 * RFC5661, Section 18.30.4:
449 * Changing the size of a file with SETATTR indirectly
450 * changes the time_modify and change attributes.
452 * (and similar for the older RFCs)
454 struct iattr size_attr
= {
455 .ia_valid
= ATTR_SIZE
| ATTR_CTIME
| ATTR_MTIME
,
456 .ia_size
= iap
->ia_size
,
459 host_err
= notify_change(dentry
, &size_attr
, NULL
);
462 iap
->ia_valid
&= ~ATTR_SIZE
;
465 * Avoid the additional setattr call below if the only other
466 * attribute that the client sends is the mtime, as we update
467 * it as part of the size change above.
469 if ((iap
->ia_valid
& ~ATTR_MTIME
) == 0)
473 iap
->ia_valid
|= ATTR_CTIME
;
474 host_err
= notify_change(dentry
, iap
, NULL
);
479 put_write_access(inode
);
482 host_err
= commit_metadata(fhp
);
483 return nfserrno(host_err
);
486 #if defined(CONFIG_NFSD_V4)
488 * NFS junction information is stored in an extended attribute.
490 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
493 * nfsd4_is_junction - Test if an object could be an NFS junction
495 * @dentry: object to test
497 * Returns 1 if "dentry" appears to contain NFS junction information.
498 * Otherwise 0 is returned.
500 int nfsd4_is_junction(struct dentry
*dentry
)
502 struct inode
*inode
= d_inode(dentry
);
506 if (inode
->i_mode
& S_IXUGO
)
508 if (!(inode
->i_mode
& S_ISVTX
))
510 if (vfs_getxattr(dentry
, NFSD_JUNCTION_XATTR_NAME
, NULL
, 0) <= 0)
514 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
515 __be32
nfsd4_set_nfs4_label(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
516 struct xdr_netobj
*label
)
520 struct dentry
*dentry
;
522 error
= fh_verify(rqstp
, fhp
, 0 /* S_IFREG */, NFSD_MAY_SATTR
);
526 dentry
= fhp
->fh_dentry
;
528 inode_lock(d_inode(dentry
));
529 host_error
= security_inode_setsecctx(dentry
, label
->data
, label
->len
);
530 inode_unlock(d_inode(dentry
));
531 return nfserrno(host_error
);
534 __be32
nfsd4_set_nfs4_label(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
535 struct xdr_netobj
*label
)
537 return nfserr_notsupp
;
541 __be32
nfsd4_clone_file_range(struct file
*src
, u64 src_pos
, struct file
*dst
,
542 u64 dst_pos
, u64 count
)
544 return nfserrno(vfs_clone_file_range(src
, src_pos
, dst
, dst_pos
,
548 ssize_t
nfsd_copy_file_range(struct file
*src
, u64 src_pos
, struct file
*dst
,
549 u64 dst_pos
, u64 count
)
553 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
554 * thread and client rpc slot. The choice of 4MB is somewhat
555 * arbitrary. We might instead base this on r/wsize, or make it
556 * tunable, or use a time instead of a byte limit, or implement
557 * asynchronous copy. In theory a client could also recognize a
558 * limit like this and pipeline multiple COPY requests.
560 count
= min_t(u64
, count
, 1 << 22);
561 return vfs_copy_file_range(src
, src_pos
, dst
, dst_pos
, count
, 0);
564 __be32
nfsd4_vfs_fallocate(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
565 struct file
*file
, loff_t offset
, loff_t len
,
570 if (!S_ISREG(file_inode(file
)->i_mode
))
573 error
= vfs_fallocate(file
, flags
, offset
, len
);
575 error
= commit_metadata(fhp
);
577 return nfserrno(error
);
579 #endif /* defined(CONFIG_NFSD_V4) */
581 #ifdef CONFIG_NFSD_V3
583 * Check server access rights to a file system object
589 static struct accessmap nfs3_regaccess
[] = {
590 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
591 { NFS3_ACCESS_EXECUTE
, NFSD_MAY_EXEC
},
592 { NFS3_ACCESS_MODIFY
, NFSD_MAY_WRITE
|NFSD_MAY_TRUNC
},
593 { NFS3_ACCESS_EXTEND
, NFSD_MAY_WRITE
},
598 static struct accessmap nfs3_diraccess
[] = {
599 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
600 { NFS3_ACCESS_LOOKUP
, NFSD_MAY_EXEC
},
601 { NFS3_ACCESS_MODIFY
, NFSD_MAY_EXEC
|NFSD_MAY_WRITE
|NFSD_MAY_TRUNC
},
602 { NFS3_ACCESS_EXTEND
, NFSD_MAY_EXEC
|NFSD_MAY_WRITE
},
603 { NFS3_ACCESS_DELETE
, NFSD_MAY_REMOVE
},
608 static struct accessmap nfs3_anyaccess
[] = {
609 /* Some clients - Solaris 2.6 at least, make an access call
610 * to the server to check for access for things like /dev/null
611 * (which really, the server doesn't care about). So
612 * We provide simple access checking for them, looking
613 * mainly at mode bits, and we make sure to ignore read-only
616 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
617 { NFS3_ACCESS_EXECUTE
, NFSD_MAY_EXEC
},
618 { NFS3_ACCESS_MODIFY
, NFSD_MAY_WRITE
|NFSD_MAY_LOCAL_ACCESS
},
619 { NFS3_ACCESS_EXTEND
, NFSD_MAY_WRITE
|NFSD_MAY_LOCAL_ACCESS
},
625 nfsd_access(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, u32
*access
, u32
*supported
)
627 struct accessmap
*map
;
628 struct svc_export
*export
;
629 struct dentry
*dentry
;
630 u32 query
, result
= 0, sresult
= 0;
633 error
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_NOP
);
637 export
= fhp
->fh_export
;
638 dentry
= fhp
->fh_dentry
;
640 if (d_is_reg(dentry
))
641 map
= nfs3_regaccess
;
642 else if (d_is_dir(dentry
))
643 map
= nfs3_diraccess
;
645 map
= nfs3_anyaccess
;
649 for (; map
->access
; map
++) {
650 if (map
->access
& query
) {
653 sresult
|= map
->access
;
655 err2
= nfsd_permission(rqstp
, export
, dentry
, map
->how
);
658 result
|= map
->access
;
661 /* the following error codes just mean the access was not allowed,
662 * rather than an error occurred */
666 /* simply don't "or" in the access bit. */
676 *supported
= sresult
;
681 #endif /* CONFIG_NFSD_V3 */
683 static int nfsd_open_break_lease(struct inode
*inode
, int access
)
687 if (access
& NFSD_MAY_NOT_BREAK_LEASE
)
689 mode
= (access
& NFSD_MAY_WRITE
) ? O_WRONLY
: O_RDONLY
;
690 return break_lease(inode
, mode
| O_NONBLOCK
);
694 * Open an existing file or directory.
695 * The may_flags argument indicates the type of open (read/write/lock)
696 * and additional flags.
697 * N.B. After this call fhp needs an fh_put
700 nfsd_open(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, umode_t type
,
701 int may_flags
, struct file
**filp
)
706 int flags
= O_RDONLY
|O_LARGEFILE
;
710 validate_process_creds();
713 * If we get here, then the client has already done an "open",
714 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
715 * in case a chmod has now revoked permission.
717 * Arguably we should also allow the owner override for
718 * directories, but we never have and it doesn't seem to have
719 * caused anyone a problem. If we were to change this, note
720 * also that our filldir callbacks would need a variant of
721 * lookup_one_len that doesn't check permissions.
724 may_flags
|= NFSD_MAY_OWNER_OVERRIDE
;
725 err
= fh_verify(rqstp
, fhp
, type
, may_flags
);
729 path
.mnt
= fhp
->fh_export
->ex_path
.mnt
;
730 path
.dentry
= fhp
->fh_dentry
;
731 inode
= d_inode(path
.dentry
);
733 /* Disallow write access to files with the append-only bit set
734 * or any access when mandatory locking enabled
737 if (IS_APPEND(inode
) && (may_flags
& NFSD_MAY_WRITE
))
740 * We must ignore files (but only files) which might have mandatory
741 * locks on them because there is no way to know if the accesser has
744 if (S_ISREG((inode
)->i_mode
) && mandatory_lock(inode
))
750 host_err
= nfsd_open_break_lease(inode
, may_flags
);
751 if (host_err
) /* NOMEM or WOULDBLOCK */
754 if (may_flags
& NFSD_MAY_WRITE
) {
755 if (may_flags
& NFSD_MAY_READ
)
756 flags
= O_RDWR
|O_LARGEFILE
;
758 flags
= O_WRONLY
|O_LARGEFILE
;
761 file
= dentry_open(&path
, flags
, current_cred());
763 host_err
= PTR_ERR(file
);
767 host_err
= ima_file_check(file
, may_flags
, 0);
773 if (may_flags
& NFSD_MAY_64BIT_COOKIE
)
774 file
->f_mode
|= FMODE_64BITHASH
;
776 file
->f_mode
|= FMODE_32BITHASH
;
780 err
= nfserrno(host_err
);
782 validate_process_creds();
787 nfsd_init_raparms(struct file
*file
)
789 struct inode
*inode
= file_inode(file
);
790 dev_t dev
= inode
->i_sb
->s_dev
;
791 ino_t ino
= inode
->i_ino
;
792 struct raparms
*ra
, **rap
, **frap
= NULL
;
795 struct raparm_hbucket
*rab
;
797 hash
= jhash_2words(dev
, ino
, 0xfeedbeef) & RAPARM_HASH_MASK
;
798 rab
= &raparm_hash
[hash
];
800 spin_lock(&rab
->pb_lock
);
801 for (rap
= &rab
->pb_head
; (ra
= *rap
); rap
= &ra
->p_next
) {
802 if (ra
->p_ino
== ino
&& ra
->p_dev
== dev
)
805 if (ra
->p_count
== 0)
808 depth
= nfsdstats
.ra_size
;
810 spin_unlock(&rab
->pb_lock
);
820 if (rap
!= &rab
->pb_head
) {
822 ra
->p_next
= rab
->pb_head
;
826 nfsdstats
.ra_depth
[depth
*10/nfsdstats
.ra_size
]++;
827 spin_unlock(&rab
->pb_lock
);
830 file
->f_ra
= ra
->p_ra
;
834 void nfsd_put_raparams(struct file
*file
, struct raparms
*ra
)
836 struct raparm_hbucket
*rab
= &raparm_hash
[ra
->p_hindex
];
838 spin_lock(&rab
->pb_lock
);
839 ra
->p_ra
= file
->f_ra
;
842 spin_unlock(&rab
->pb_lock
);
846 * Grab and keep cached pages associated with a file in the svc_rqst
847 * so that they can be passed to the network sendmsg/sendpage routines
848 * directly. They will be released after the sending has completed.
851 nfsd_splice_actor(struct pipe_inode_info
*pipe
, struct pipe_buffer
*buf
,
852 struct splice_desc
*sd
)
854 struct svc_rqst
*rqstp
= sd
->u
.data
;
855 struct page
**pp
= rqstp
->rq_next_page
;
856 struct page
*page
= buf
->page
;
861 if (rqstp
->rq_res
.page_len
== 0) {
863 put_page(*rqstp
->rq_next_page
);
864 *(rqstp
->rq_next_page
++) = page
;
865 rqstp
->rq_res
.page_base
= buf
->offset
;
866 rqstp
->rq_res
.page_len
= size
;
867 } else if (page
!= pp
[-1]) {
869 if (*rqstp
->rq_next_page
)
870 put_page(*rqstp
->rq_next_page
);
871 *(rqstp
->rq_next_page
++) = page
;
872 rqstp
->rq_res
.page_len
+= size
;
874 rqstp
->rq_res
.page_len
+= size
;
879 static int nfsd_direct_splice_actor(struct pipe_inode_info
*pipe
,
880 struct splice_desc
*sd
)
882 return __splice_from_pipe(pipe
, sd
, nfsd_splice_actor
);
886 nfsd_finish_read(struct file
*file
, unsigned long *count
, int host_err
)
889 nfsdstats
.io_read
+= host_err
;
891 fsnotify_access(file
);
894 return nfserrno(host_err
);
897 __be32
nfsd_splice_read(struct svc_rqst
*rqstp
,
898 struct file
*file
, loff_t offset
, unsigned long *count
)
900 struct splice_desc sd
= {
908 rqstp
->rq_next_page
= rqstp
->rq_respages
+ 1;
909 host_err
= splice_direct_to_actor(file
, &sd
, nfsd_direct_splice_actor
);
910 return nfsd_finish_read(file
, count
, host_err
);
913 __be32
nfsd_readv(struct file
*file
, loff_t offset
, struct kvec
*vec
, int vlen
,
914 unsigned long *count
)
916 struct iov_iter iter
;
919 iov_iter_kvec(&iter
, READ
| ITER_KVEC
, vec
, vlen
, *count
);
920 host_err
= vfs_iter_read(file
, &iter
, &offset
, 0);
922 return nfsd_finish_read(file
, count
, host_err
);
926 * Gathered writes: If another process is currently writing to the file,
927 * there's a high chance this is another nfsd (triggered by a bulk write
928 * from a client's biod). Rather than syncing the file with each write
929 * request, we sleep for 10 msec.
931 * I don't know if this roughly approximates C. Juszak's idea of
932 * gathered writes, but it's a nice and simple solution (IMHO), and it
935 * Note: we do this only in the NFSv2 case, since v3 and higher have a
936 * better tool (separate unstable writes and commits) for solving this
939 static int wait_for_concurrent_writes(struct file
*file
)
941 struct inode
*inode
= file_inode(file
);
942 static ino_t last_ino
;
943 static dev_t last_dev
;
946 if (atomic_read(&inode
->i_writecount
) > 1
947 || (last_ino
== inode
->i_ino
&& last_dev
== inode
->i_sb
->s_dev
)) {
948 dprintk("nfsd: write defer %d\n", task_pid_nr(current
));
950 dprintk("nfsd: write resume %d\n", task_pid_nr(current
));
953 if (inode
->i_state
& I_DIRTY
) {
954 dprintk("nfsd: write sync %d\n", task_pid_nr(current
));
955 err
= vfs_fsync(file
, 0);
957 last_ino
= inode
->i_ino
;
958 last_dev
= inode
->i_sb
->s_dev
;
963 nfsd_vfs_write(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct file
*file
,
964 loff_t offset
, struct kvec
*vec
, int vlen
,
965 unsigned long *cnt
, int stable
)
967 struct svc_export
*exp
;
968 struct iov_iter iter
;
973 unsigned int pflags
= current
->flags
;
976 if (test_bit(RQ_LOCAL
, &rqstp
->rq_flags
))
978 * We want less throttling in balance_dirty_pages()
979 * and shrink_inactive_list() 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_LESS_THROTTLE
;
985 exp
= fhp
->fh_export
;
986 use_wgather
= (rqstp
->rq_vers
== 2) && EX_WGATHER(exp
);
989 stable
= NFS_UNSTABLE
;
991 if (stable
&& !use_wgather
)
994 iov_iter_kvec(&iter
, WRITE
| ITER_KVEC
, vec
, vlen
, *cnt
);
995 host_err
= vfs_iter_write(file
, &iter
, &pos
, flags
);
999 nfsdstats
.io_write
+= host_err
;
1000 fsnotify_modify(file
);
1002 if (stable
&& use_wgather
)
1003 host_err
= wait_for_concurrent_writes(file
);
1006 dprintk("nfsd: write complete host_err=%d\n", host_err
);
1010 err
= nfserrno(host_err
);
1011 if (test_bit(RQ_LOCAL
, &rqstp
->rq_flags
))
1012 current_restore_flags(pflags
, PF_LESS_THROTTLE
);
1017 * Read data from a file. count must contain the requested read count
1018 * on entry. On return, *count contains the number of bytes actually read.
1019 * N.B. After this call fhp needs an fh_put
1021 __be32
nfsd_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1022 loff_t offset
, struct kvec
*vec
, int vlen
, unsigned long *count
)
1028 trace_read_start(rqstp
, fhp
, offset
, vlen
);
1029 err
= nfsd_open(rqstp
, fhp
, S_IFREG
, NFSD_MAY_READ
, &file
);
1033 ra
= nfsd_init_raparms(file
);
1035 trace_read_opened(rqstp
, fhp
, offset
, vlen
);
1037 if (file
->f_op
->splice_read
&& test_bit(RQ_SPLICE_OK
, &rqstp
->rq_flags
))
1038 err
= nfsd_splice_read(rqstp
, file
, offset
, count
);
1040 err
= nfsd_readv(file
, offset
, vec
, vlen
, count
);
1042 trace_read_io_done(rqstp
, fhp
, offset
, vlen
);
1045 nfsd_put_raparams(file
, ra
);
1048 trace_read_done(rqstp
, fhp
, offset
, vlen
);
1054 * Write data to a file.
1055 * The stable flag requests synchronous writes.
1056 * N.B. After this call fhp needs an fh_put
1059 nfsd_write(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, loff_t offset
,
1060 struct kvec
*vec
, int vlen
, unsigned long *cnt
, int stable
)
1062 struct file
*file
= NULL
;
1065 trace_write_start(rqstp
, fhp
, offset
, vlen
);
1067 err
= nfsd_open(rqstp
, fhp
, S_IFREG
, NFSD_MAY_WRITE
, &file
);
1071 trace_write_opened(rqstp
, fhp
, offset
, vlen
);
1072 err
= nfsd_vfs_write(rqstp
, fhp
, file
, offset
, vec
, vlen
, cnt
, stable
);
1073 trace_write_io_done(rqstp
, fhp
, offset
, vlen
);
1076 trace_write_done(rqstp
, fhp
, offset
, vlen
);
1080 #ifdef CONFIG_NFSD_V3
1082 * Commit all pending writes to stable storage.
1084 * Note: we only guarantee that data that lies within the range specified
1085 * by the 'offset' and 'count' parameters will be synced.
1087 * Unfortunately we cannot lock the file to make sure we return full WCC
1088 * data to the client, as locking happens lower down in the filesystem.
1091 nfsd_commit(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1092 loff_t offset
, unsigned long count
)
1095 loff_t end
= LLONG_MAX
;
1096 __be32 err
= nfserr_inval
;
1101 end
= offset
+ (loff_t
)count
- 1;
1106 err
= nfsd_open(rqstp
, fhp
, S_IFREG
,
1107 NFSD_MAY_WRITE
|NFSD_MAY_NOT_BREAK_LEASE
, &file
);
1110 if (EX_ISSYNC(fhp
->fh_export
)) {
1111 int err2
= vfs_fsync_range(file
, offset
, end
, 0);
1113 if (err2
!= -EINVAL
)
1114 err
= nfserrno(err2
);
1116 err
= nfserr_notsupp
;
1123 #endif /* CONFIG_NFSD_V3 */
1126 nfsd_create_setattr(struct svc_rqst
*rqstp
, struct svc_fh
*resfhp
,
1130 * Mode has already been set earlier in create:
1132 iap
->ia_valid
&= ~ATTR_MODE
;
1134 * Setting uid/gid works only for root. Irix appears to
1135 * send along the gid on create when it tries to implement
1136 * setgid directories via NFS:
1138 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID
))
1139 iap
->ia_valid
&= ~(ATTR_UID
|ATTR_GID
);
1141 return nfsd_setattr(rqstp
, resfhp
, iap
, 0, (time_t)0);
1142 /* Callers expect file metadata to be committed here */
1143 return nfserrno(commit_metadata(resfhp
));
1146 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1147 * setting size to 0 may fail for some specific file systems by the permission
1148 * checking which requires WRITE permission but the mode is 000.
1149 * we ignore the resizing(to 0) on the just new created file, since the size is
1150 * 0 after file created.
1152 * call this only after vfs_create() is called.
1155 nfsd_check_ignore_resizing(struct iattr
*iap
)
1157 if ((iap
->ia_valid
& ATTR_SIZE
) && (iap
->ia_size
== 0))
1158 iap
->ia_valid
&= ~ATTR_SIZE
;
1161 /* The parent directory should already be locked: */
1163 nfsd_create_locked(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1164 char *fname
, int flen
, struct iattr
*iap
,
1165 int type
, dev_t rdev
, struct svc_fh
*resfhp
)
1167 struct dentry
*dentry
, *dchild
;
1173 dentry
= fhp
->fh_dentry
;
1174 dirp
= d_inode(dentry
);
1176 dchild
= dget(resfhp
->fh_dentry
);
1177 if (!fhp
->fh_locked
) {
1178 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
1184 err
= nfsd_permission(rqstp
, fhp
->fh_export
, dentry
, NFSD_MAY_CREATE
);
1188 if (!(iap
->ia_valid
& ATTR_MODE
))
1190 iap
->ia_mode
= (iap
->ia_mode
& S_IALLUGO
) | type
;
1196 host_err
= vfs_create(dirp
, dchild
, iap
->ia_mode
, true);
1198 nfsd_check_ignore_resizing(iap
);
1201 host_err
= vfs_mkdir(dirp
, dchild
, iap
->ia_mode
);
1207 host_err
= vfs_mknod(dirp
, dchild
, iap
->ia_mode
, rdev
);
1210 printk(KERN_WARNING
"nfsd: bad file type %o in nfsd_create\n",
1217 err
= nfsd_create_setattr(rqstp
, resfhp
, iap
);
1220 * nfsd_create_setattr already committed the child. Transactional
1221 * filesystems had a chance to commit changes for both parent and
1222 * child simultaneously making the following commit_metadata a
1225 err2
= nfserrno(commit_metadata(fhp
));
1229 * Update the file handle to get the new inode info.
1232 err
= fh_update(resfhp
);
1238 err
= nfserrno(host_err
);
1243 * Create a filesystem object (regular, directory, special).
1244 * Note that the parent directory is left locked.
1246 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1249 nfsd_create(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1250 char *fname
, int flen
, struct iattr
*iap
,
1251 int type
, dev_t rdev
, struct svc_fh
*resfhp
)
1253 struct dentry
*dentry
, *dchild
= NULL
;
1258 if (isdotent(fname
, flen
))
1259 return nfserr_exist
;
1261 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_NOP
);
1265 dentry
= fhp
->fh_dentry
;
1266 dirp
= d_inode(dentry
);
1268 host_err
= fh_want_write(fhp
);
1270 return nfserrno(host_err
);
1272 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1273 dchild
= lookup_one_len(fname
, dentry
, flen
);
1274 host_err
= PTR_ERR(dchild
);
1276 return nfserrno(host_err
);
1277 err
= fh_compose(resfhp
, fhp
->fh_export
, dchild
, fhp
);
1279 * We unconditionally drop our ref to dchild as fh_compose will have
1280 * already grabbed its own ref for it.
1285 return nfsd_create_locked(rqstp
, fhp
, fname
, flen
, iap
, type
,
1289 #ifdef CONFIG_NFSD_V3
1292 * NFSv3 and NFSv4 version of nfsd_create
1295 do_nfsd_create(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1296 char *fname
, int flen
, struct iattr
*iap
,
1297 struct svc_fh
*resfhp
, int createmode
, u32
*verifier
,
1298 bool *truncp
, bool *created
)
1300 struct dentry
*dentry
, *dchild
= NULL
;
1304 __u32 v_mtime
=0, v_atime
=0;
1310 if (isdotent(fname
, flen
))
1312 if (!(iap
->ia_valid
& ATTR_MODE
))
1314 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_EXEC
);
1318 dentry
= fhp
->fh_dentry
;
1319 dirp
= d_inode(dentry
);
1321 host_err
= fh_want_write(fhp
);
1325 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1328 * Compose the response file handle.
1330 dchild
= lookup_one_len(fname
, dentry
, flen
);
1331 host_err
= PTR_ERR(dchild
);
1335 /* If file doesn't exist, check for permissions to create one */
1336 if (d_really_is_negative(dchild
)) {
1337 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1342 err
= fh_compose(resfhp
, fhp
->fh_export
, dchild
, fhp
);
1346 if (nfsd_create_is_exclusive(createmode
)) {
1347 /* solaris7 gets confused (bugid 4218508) if these have
1348 * the high bit set, so just clear the high bits. If this is
1349 * ever changed to use different attrs for storing the
1350 * verifier, then do_open_lookup() will also need to be fixed
1353 v_mtime
= verifier
[0]&0x7fffffff;
1354 v_atime
= verifier
[1]&0x7fffffff;
1357 if (d_really_is_positive(dchild
)) {
1360 switch (createmode
) {
1361 case NFS3_CREATE_UNCHECKED
:
1362 if (! d_is_reg(dchild
))
1365 /* in nfsv4, we need to treat this case a little
1366 * differently. we don't want to truncate the
1367 * file now; this would be wrong if the OPEN
1368 * fails for some other reason. furthermore,
1369 * if the size is nonzero, we should ignore it
1370 * according to spec!
1372 *truncp
= (iap
->ia_valid
& ATTR_SIZE
) && !iap
->ia_size
;
1375 iap
->ia_valid
&= ATTR_SIZE
;
1379 case NFS3_CREATE_EXCLUSIVE
:
1380 if ( d_inode(dchild
)->i_mtime
.tv_sec
== v_mtime
1381 && d_inode(dchild
)->i_atime
.tv_sec
== v_atime
1382 && d_inode(dchild
)->i_size
== 0 ) {
1387 case NFS4_CREATE_EXCLUSIVE4_1
:
1388 if ( d_inode(dchild
)->i_mtime
.tv_sec
== v_mtime
1389 && d_inode(dchild
)->i_atime
.tv_sec
== v_atime
1390 && d_inode(dchild
)->i_size
== 0 ) {
1396 case NFS3_CREATE_GUARDED
:
1403 host_err
= vfs_create(dirp
, dchild
, iap
->ia_mode
, true);
1411 nfsd_check_ignore_resizing(iap
);
1413 if (nfsd_create_is_exclusive(createmode
)) {
1414 /* Cram the verifier into atime/mtime */
1415 iap
->ia_valid
= ATTR_MTIME
|ATTR_ATIME
1416 | ATTR_MTIME_SET
|ATTR_ATIME_SET
;
1417 /* XXX someone who knows this better please fix it for nsec */
1418 iap
->ia_mtime
.tv_sec
= v_mtime
;
1419 iap
->ia_atime
.tv_sec
= v_atime
;
1420 iap
->ia_mtime
.tv_nsec
= 0;
1421 iap
->ia_atime
.tv_nsec
= 0;
1425 err
= nfsd_create_setattr(rqstp
, resfhp
, iap
);
1428 * nfsd_create_setattr already committed the child
1429 * (and possibly also the parent).
1432 err
= nfserrno(commit_metadata(fhp
));
1435 * Update the filehandle to get the new inode info.
1438 err
= fh_update(resfhp
);
1442 if (dchild
&& !IS_ERR(dchild
))
1448 err
= nfserrno(host_err
);
1451 #endif /* CONFIG_NFSD_V3 */
1454 * Read a symlink. On entry, *lenp must contain the maximum path length that
1455 * fits into the buffer. On return, it contains the true length.
1456 * N.B. After this call fhp needs an fh_put
1459 nfsd_readlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *buf
, int *lenp
)
1464 DEFINE_DELAYED_CALL(done
);
1467 err
= fh_verify(rqstp
, fhp
, S_IFLNK
, NFSD_MAY_NOP
);
1471 path
.mnt
= fhp
->fh_export
->ex_path
.mnt
;
1472 path
.dentry
= fhp
->fh_dentry
;
1474 if (unlikely(!d_is_symlink(path
.dentry
)))
1475 return nfserr_inval
;
1479 link
= vfs_get_link(path
.dentry
, &done
);
1481 return nfserrno(PTR_ERR(link
));
1486 memcpy(buf
, link
, *lenp
);
1487 do_delayed_call(&done
);
1492 * Create a symlink and look up its inode
1493 * N.B. After this call _both_ fhp and resfhp need an fh_put
1496 nfsd_symlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1497 char *fname
, int flen
,
1499 struct svc_fh
*resfhp
)
1501 struct dentry
*dentry
, *dnew
;
1506 if (!flen
|| path
[0] == '\0')
1509 if (isdotent(fname
, flen
))
1512 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1516 host_err
= fh_want_write(fhp
);
1521 dentry
= fhp
->fh_dentry
;
1522 dnew
= lookup_one_len(fname
, dentry
, flen
);
1523 host_err
= PTR_ERR(dnew
);
1527 host_err
= vfs_symlink(d_inode(dentry
), dnew
, path
);
1528 err
= nfserrno(host_err
);
1530 err
= nfserrno(commit_metadata(fhp
));
1535 cerr
= fh_compose(resfhp
, fhp
->fh_export
, dnew
, fhp
);
1537 if (err
==0) err
= cerr
;
1542 err
= nfserrno(host_err
);
1548 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1551 nfsd_link(struct svc_rqst
*rqstp
, struct svc_fh
*ffhp
,
1552 char *name
, int len
, struct svc_fh
*tfhp
)
1554 struct dentry
*ddir
, *dnew
, *dold
;
1559 err
= fh_verify(rqstp
, ffhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1562 err
= fh_verify(rqstp
, tfhp
, 0, NFSD_MAY_NOP
);
1566 if (d_is_dir(tfhp
->fh_dentry
))
1572 if (isdotent(name
, len
))
1575 host_err
= fh_want_write(tfhp
);
1577 err
= nfserrno(host_err
);
1581 fh_lock_nested(ffhp
, I_MUTEX_PARENT
);
1582 ddir
= ffhp
->fh_dentry
;
1583 dirp
= d_inode(ddir
);
1585 dnew
= lookup_one_len(name
, ddir
, len
);
1586 host_err
= PTR_ERR(dnew
);
1590 dold
= tfhp
->fh_dentry
;
1593 if (d_really_is_negative(dold
))
1595 host_err
= vfs_link(dold
, dirp
, dnew
, NULL
);
1597 err
= nfserrno(commit_metadata(ffhp
));
1599 err
= nfserrno(commit_metadata(tfhp
));
1601 if (host_err
== -EXDEV
&& rqstp
->rq_vers
== 2)
1604 err
= nfserrno(host_err
);
1610 fh_drop_write(tfhp
);
1615 err
= nfserrno(host_err
);
1621 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1624 nfsd_rename(struct svc_rqst
*rqstp
, struct svc_fh
*ffhp
, char *fname
, int flen
,
1625 struct svc_fh
*tfhp
, char *tname
, int tlen
)
1627 struct dentry
*fdentry
, *tdentry
, *odentry
, *ndentry
, *trap
;
1628 struct inode
*fdir
, *tdir
;
1632 err
= fh_verify(rqstp
, ffhp
, S_IFDIR
, NFSD_MAY_REMOVE
);
1635 err
= fh_verify(rqstp
, tfhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1639 fdentry
= ffhp
->fh_dentry
;
1640 fdir
= d_inode(fdentry
);
1642 tdentry
= tfhp
->fh_dentry
;
1643 tdir
= d_inode(tdentry
);
1646 if (!flen
|| isdotent(fname
, flen
) || !tlen
|| isdotent(tname
, tlen
))
1649 host_err
= fh_want_write(ffhp
);
1651 err
= nfserrno(host_err
);
1655 /* cannot use fh_lock as we need deadlock protective ordering
1656 * so do it by hand */
1657 trap
= lock_rename(tdentry
, fdentry
);
1658 ffhp
->fh_locked
= tfhp
->fh_locked
= true;
1662 odentry
= lookup_one_len(fname
, fdentry
, flen
);
1663 host_err
= PTR_ERR(odentry
);
1664 if (IS_ERR(odentry
))
1668 if (d_really_is_negative(odentry
))
1671 if (odentry
== trap
)
1674 ndentry
= lookup_one_len(tname
, tdentry
, tlen
);
1675 host_err
= PTR_ERR(ndentry
);
1676 if (IS_ERR(ndentry
))
1678 host_err
= -ENOTEMPTY
;
1679 if (ndentry
== trap
)
1683 if (ffhp
->fh_export
->ex_path
.mnt
!= tfhp
->fh_export
->ex_path
.mnt
)
1685 if (ffhp
->fh_export
->ex_path
.dentry
!= tfhp
->fh_export
->ex_path
.dentry
)
1688 host_err
= vfs_rename(fdir
, odentry
, tdir
, ndentry
, NULL
, 0);
1690 host_err
= commit_metadata(tfhp
);
1692 host_err
= commit_metadata(ffhp
);
1699 err
= nfserrno(host_err
);
1701 * We cannot rely on fh_unlock on the two filehandles,
1702 * as that would do the wrong thing if the two directories
1703 * were the same, so again we do it by hand.
1705 fill_post_wcc(ffhp
);
1706 fill_post_wcc(tfhp
);
1707 unlock_rename(tdentry
, fdentry
);
1708 ffhp
->fh_locked
= tfhp
->fh_locked
= false;
1709 fh_drop_write(ffhp
);
1716 * Unlink a file or directory
1717 * N.B. After this call fhp needs an fh_put
1720 nfsd_unlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, int type
,
1721 char *fname
, int flen
)
1723 struct dentry
*dentry
, *rdentry
;
1729 if (!flen
|| isdotent(fname
, flen
))
1731 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_REMOVE
);
1735 host_err
= fh_want_write(fhp
);
1739 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1740 dentry
= fhp
->fh_dentry
;
1741 dirp
= d_inode(dentry
);
1743 rdentry
= lookup_one_len(fname
, dentry
, flen
);
1744 host_err
= PTR_ERR(rdentry
);
1745 if (IS_ERR(rdentry
))
1748 if (d_really_is_negative(rdentry
)) {
1755 type
= d_inode(rdentry
)->i_mode
& S_IFMT
;
1757 if (type
!= S_IFDIR
)
1758 host_err
= vfs_unlink(dirp
, rdentry
, NULL
);
1760 host_err
= vfs_rmdir(dirp
, rdentry
);
1762 host_err
= commit_metadata(fhp
);
1766 err
= nfserrno(host_err
);
1772 * We do this buffering because we must not call back into the file
1773 * system's ->lookup() method from the filldir callback. That may well
1774 * deadlock a number of file systems.
1776 * This is based heavily on the implementation of same in XFS.
1778 struct buffered_dirent
{
1782 unsigned int d_type
;
1786 struct readdir_data
{
1787 struct dir_context ctx
;
1793 static int nfsd_buffered_filldir(struct dir_context
*ctx
, const char *name
,
1794 int namlen
, loff_t offset
, u64 ino
,
1795 unsigned int d_type
)
1797 struct readdir_data
*buf
=
1798 container_of(ctx
, struct readdir_data
, ctx
);
1799 struct buffered_dirent
*de
= (void *)(buf
->dirent
+ buf
->used
);
1800 unsigned int reclen
;
1802 reclen
= ALIGN(sizeof(struct buffered_dirent
) + namlen
, sizeof(u64
));
1803 if (buf
->used
+ reclen
> PAGE_SIZE
) {
1808 de
->namlen
= namlen
;
1809 de
->offset
= offset
;
1811 de
->d_type
= d_type
;
1812 memcpy(de
->name
, name
, namlen
);
1813 buf
->used
+= reclen
;
1818 static __be32
nfsd_buffered_readdir(struct file
*file
, nfsd_filldir_t func
,
1819 struct readdir_cd
*cdp
, loff_t
*offsetp
)
1821 struct buffered_dirent
*de
;
1825 struct readdir_data buf
= {
1826 .ctx
.actor
= nfsd_buffered_filldir
,
1827 .dirent
= (void *)__get_free_page(GFP_KERNEL
)
1831 return nfserrno(-ENOMEM
);
1836 unsigned int reclen
;
1838 cdp
->err
= nfserr_eof
; /* will be cleared on successful read */
1842 host_err
= iterate_dir(file
, &buf
.ctx
);
1854 de
= (struct buffered_dirent
*)buf
.dirent
;
1856 offset
= de
->offset
;
1858 if (func(cdp
, de
->name
, de
->namlen
, de
->offset
,
1859 de
->ino
, de
->d_type
))
1862 if (cdp
->err
!= nfs_ok
)
1865 reclen
= ALIGN(sizeof(*de
) + de
->namlen
,
1868 de
= (struct buffered_dirent
*)((char *)de
+ reclen
);
1870 if (size
> 0) /* We bailed out early */
1873 offset
= vfs_llseek(file
, 0, SEEK_CUR
);
1876 free_page((unsigned long)(buf
.dirent
));
1879 return nfserrno(host_err
);
1886 * Read entries from a directory.
1887 * The NFSv3/4 verifier we ignore for now.
1890 nfsd_readdir(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, loff_t
*offsetp
,
1891 struct readdir_cd
*cdp
, nfsd_filldir_t func
)
1895 loff_t offset
= *offsetp
;
1896 int may_flags
= NFSD_MAY_READ
;
1898 /* NFSv2 only supports 32 bit cookies */
1899 if (rqstp
->rq_vers
> 2)
1900 may_flags
|= NFSD_MAY_64BIT_COOKIE
;
1902 err
= nfsd_open(rqstp
, fhp
, S_IFDIR
, may_flags
, &file
);
1906 offset
= vfs_llseek(file
, offset
, SEEK_SET
);
1908 err
= nfserrno((int)offset
);
1912 err
= nfsd_buffered_readdir(file
, func
, cdp
, offsetp
);
1914 if (err
== nfserr_eof
|| err
== nfserr_toosmall
)
1915 err
= nfs_ok
; /* can still be found in ->err */
1923 * Get file system stats
1924 * N.B. After this call fhp needs an fh_put
1927 nfsd_statfs(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct kstatfs
*stat
, int access
)
1931 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_NOP
| access
);
1933 struct path path
= {
1934 .mnt
= fhp
->fh_export
->ex_path
.mnt
,
1935 .dentry
= fhp
->fh_dentry
,
1937 if (vfs_statfs(&path
, stat
))
1943 static int exp_rdonly(struct svc_rqst
*rqstp
, struct svc_export
*exp
)
1945 return nfsexp_flags(rqstp
, exp
) & NFSEXP_READONLY
;
1949 * Check for a user's access permissions to this inode.
1952 nfsd_permission(struct svc_rqst
*rqstp
, struct svc_export
*exp
,
1953 struct dentry
*dentry
, int acc
)
1955 struct inode
*inode
= d_inode(dentry
);
1958 if ((acc
& NFSD_MAY_MASK
) == NFSD_MAY_NOP
)
1961 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
1963 (acc
& NFSD_MAY_READ
)? " read" : "",
1964 (acc
& NFSD_MAY_WRITE
)? " write" : "",
1965 (acc
& NFSD_MAY_EXEC
)? " exec" : "",
1966 (acc
& NFSD_MAY_SATTR
)? " sattr" : "",
1967 (acc
& NFSD_MAY_TRUNC
)? " trunc" : "",
1968 (acc
& NFSD_MAY_LOCK
)? " lock" : "",
1969 (acc
& NFSD_MAY_OWNER_OVERRIDE
)? " owneroverride" : "",
1971 IS_IMMUTABLE(inode
)? " immut" : "",
1972 IS_APPEND(inode
)? " append" : "",
1973 __mnt_is_readonly(exp
->ex_path
.mnt
)? " ro" : "");
1974 dprintk(" owner %d/%d user %d/%d\n",
1975 inode
->i_uid
, inode
->i_gid
, current_fsuid(), current_fsgid());
1978 /* Normally we reject any write/sattr etc access on a read-only file
1979 * system. But if it is IRIX doing check on write-access for a
1980 * device special file, we ignore rofs.
1982 if (!(acc
& NFSD_MAY_LOCAL_ACCESS
))
1983 if (acc
& (NFSD_MAY_WRITE
| NFSD_MAY_SATTR
| NFSD_MAY_TRUNC
)) {
1984 if (exp_rdonly(rqstp
, exp
) ||
1985 __mnt_is_readonly(exp
->ex_path
.mnt
))
1987 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode
))
1990 if ((acc
& NFSD_MAY_TRUNC
) && IS_APPEND(inode
))
1993 if (acc
& NFSD_MAY_LOCK
) {
1994 /* If we cannot rely on authentication in NLM requests,
1995 * just allow locks, otherwise require read permission, or
1998 if (exp
->ex_flags
& NFSEXP_NOAUTHNLM
)
2001 acc
= NFSD_MAY_READ
| NFSD_MAY_OWNER_OVERRIDE
;
2004 * The file owner always gets access permission for accesses that
2005 * would normally be checked at open time. This is to make
2006 * file access work even when the client has done a fchmod(fd, 0).
2008 * However, `cp foo bar' should fail nevertheless when bar is
2009 * readonly. A sensible way to do this might be to reject all
2010 * attempts to truncate a read-only file, because a creat() call
2011 * always implies file truncation.
2012 * ... but this isn't really fair. A process may reasonably call
2013 * ftruncate on an open file descriptor on a file with perm 000.
2014 * We must trust the client to do permission checking - using "ACCESS"
2017 if ((acc
& NFSD_MAY_OWNER_OVERRIDE
) &&
2018 uid_eq(inode
->i_uid
, current_fsuid()))
2021 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2022 err
= inode_permission(inode
, acc
& (MAY_READ
|MAY_WRITE
|MAY_EXEC
));
2024 /* Allow read access to binaries even when mode 111 */
2025 if (err
== -EACCES
&& S_ISREG(inode
->i_mode
) &&
2026 (acc
== (NFSD_MAY_READ
| NFSD_MAY_OWNER_OVERRIDE
) ||
2027 acc
== (NFSD_MAY_READ
| NFSD_MAY_READ_IF_EXEC
)))
2028 err
= inode_permission(inode
, MAY_EXEC
);
2030 return err
? nfserrno(err
) : 0;
2034 nfsd_racache_shutdown(void)
2036 struct raparms
*raparm
, *last_raparm
;
2039 dprintk("nfsd: freeing readahead buffers.\n");
2041 for (i
= 0; i
< RAPARM_HASH_SIZE
; i
++) {
2042 raparm
= raparm_hash
[i
].pb_head
;
2044 last_raparm
= raparm
;
2045 raparm
= raparm
->p_next
;
2048 raparm_hash
[i
].pb_head
= NULL
;
2052 * Initialize readahead param cache
2055 nfsd_racache_init(int cache_size
)
2060 struct raparms
**raparm
= NULL
;
2063 if (raparm_hash
[0].pb_head
)
2065 nperbucket
= DIV_ROUND_UP(cache_size
, RAPARM_HASH_SIZE
);
2066 nperbucket
= max(2, nperbucket
);
2067 cache_size
= nperbucket
* RAPARM_HASH_SIZE
;
2069 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size
);
2071 for (i
= 0; i
< RAPARM_HASH_SIZE
; i
++) {
2072 spin_lock_init(&raparm_hash
[i
].pb_lock
);
2074 raparm
= &raparm_hash
[i
].pb_head
;
2075 for (j
= 0; j
< nperbucket
; j
++) {
2076 *raparm
= kzalloc(sizeof(struct raparms
), GFP_KERNEL
);
2079 raparm
= &(*raparm
)->p_next
;
2084 nfsdstats
.ra_size
= cache_size
;
2088 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2089 nfsd_racache_shutdown();