1 // SPDX-License-Identifier: GPL-2.0
3 * File operations used by nfsd. Some of these have been ripped from
4 * other parts of the kernel because they weren't exported, others
5 * are partial duplicates with added or changed functionality.
7 * Note that several functions dget() the dentry upon which they want
8 * to act, most notably those that create directory entries. Response
9 * dentry's are dput()'d if necessary in the release callback.
10 * So if you notice code paths that apparently fail to dput() the
11 * dentry, don't worry--they have been taken care of.
13 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
14 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
18 #include <linux/file.h>
19 #include <linux/splice.h>
20 #include <linux/falloc.h>
21 #include <linux/fcntl.h>
22 #include <linux/namei.h>
23 #include <linux/delay.h>
24 #include <linux/fsnotify.h>
25 #include <linux/posix_acl_xattr.h>
26 #include <linux/xattr.h>
27 #include <linux/jhash.h>
28 #include <linux/ima.h>
29 #include <linux/slab.h>
30 #include <linux/uaccess.h>
31 #include <linux/exportfs.h>
32 #include <linux/writeback.h>
33 #include <linux/security.h>
37 #endif /* CONFIG_NFSD_V3 */
40 #include "../internal.h"
43 #endif /* CONFIG_NFSD_V4 */
49 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
53 * This is a cache of readahead params that help us choose the proper
54 * readahead strategy. Initially, we set all readahead parameters to 0
55 * and let the VFS handle things.
56 * If you increase the number of cached files very much, you'll need to
57 * add a hash table here.
60 struct raparms
*p_next
;
65 struct file_ra_state p_ra
;
66 unsigned int p_hindex
;
69 struct raparm_hbucket
{
70 struct raparms
*pb_head
;
72 } ____cacheline_aligned_in_smp
;
74 #define RAPARM_HASH_BITS 4
75 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS)
76 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1)
77 static struct raparm_hbucket raparm_hash
[RAPARM_HASH_SIZE
];
80 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
82 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
83 * or nfs_ok having possibly changed *dpp and *expp
86 nfsd_cross_mnt(struct svc_rqst
*rqstp
, struct dentry
**dpp
,
87 struct svc_export
**expp
)
89 struct svc_export
*exp
= *expp
, *exp2
= NULL
;
90 struct dentry
*dentry
= *dpp
;
91 struct path path
= {.mnt
= mntget(exp
->ex_path
.mnt
),
92 .dentry
= dget(dentry
)};
95 err
= follow_down(&path
);
98 if (path
.mnt
== exp
->ex_path
.mnt
&& path
.dentry
== dentry
&&
99 nfsd_mountpoint(dentry
, exp
) == 2) {
100 /* This is only a mountpoint in some other namespace */
105 exp2
= rqst_exp_get_by_name(rqstp
, &path
);
109 * We normally allow NFS clients to continue
110 * "underneath" a mountpoint that is not exported.
111 * The exception is V4ROOT, where no traversal is ever
112 * allowed without an explicit export of the new
115 if (err
== -ENOENT
&& !(exp
->ex_flags
& NFSEXP_V4ROOT
))
120 if (nfsd_v4client(rqstp
) ||
121 (exp
->ex_flags
& NFSEXP_CROSSMOUNT
) || EX_NOHIDE(exp2
)) {
122 /* successfully crossed mount point */
124 * This is subtle: path.dentry is *not* on path.mnt
125 * at this point. The only reason we are safe is that
126 * original mnt is pinned down by exp, so we should
127 * put path *before* putting exp
130 path
.dentry
= dentry
;
140 static void follow_to_parent(struct path
*path
)
144 while (path
->dentry
== path
->mnt
->mnt_root
&& follow_up(path
))
146 dp
= dget_parent(path
->dentry
);
151 static int nfsd_lookup_parent(struct svc_rqst
*rqstp
, struct dentry
*dparent
, struct svc_export
**exp
, struct dentry
**dentryp
)
153 struct svc_export
*exp2
;
154 struct path path
= {.mnt
= mntget((*exp
)->ex_path
.mnt
),
155 .dentry
= dget(dparent
)};
157 follow_to_parent(&path
);
159 exp2
= rqst_exp_parent(rqstp
, &path
);
160 if (PTR_ERR(exp2
) == -ENOENT
) {
161 *dentryp
= dget(dparent
);
162 } else if (IS_ERR(exp2
)) {
164 return PTR_ERR(exp2
);
166 *dentryp
= dget(path
.dentry
);
175 * For nfsd purposes, we treat V4ROOT exports as though there was an
176 * export at *every* directory.
178 * '1' if this dentry *must* be an export point,
179 * '2' if it might be, if there is really a mount here, and
180 * '0' if there is no chance of an export point here.
182 int nfsd_mountpoint(struct dentry
*dentry
, struct svc_export
*exp
)
184 if (!d_inode(dentry
))
186 if (exp
->ex_flags
& NFSEXP_V4ROOT
)
188 if (nfsd4_is_junction(dentry
))
190 if (d_mountpoint(dentry
))
192 * Might only be a mountpoint in a different namespace,
193 * but we need to check.
200 nfsd_lookup_dentry(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
201 const char *name
, unsigned int len
,
202 struct svc_export
**exp_ret
, struct dentry
**dentry_ret
)
204 struct svc_export
*exp
;
205 struct dentry
*dparent
;
206 struct dentry
*dentry
;
209 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp
), len
,name
);
211 dparent
= fhp
->fh_dentry
;
212 exp
= exp_get(fhp
->fh_export
);
214 /* Lookup the name, but don't follow links */
215 if (isdotent(name
, len
)) {
217 dentry
= dget(dparent
);
218 else if (dparent
!= exp
->ex_path
.dentry
)
219 dentry
= dget_parent(dparent
);
220 else if (!EX_NOHIDE(exp
) && !nfsd_v4client(rqstp
))
221 dentry
= dget(dparent
); /* .. == . just like at / */
223 /* checking mountpoint crossing is very different when stepping up */
224 host_err
= nfsd_lookup_parent(rqstp
, dparent
, &exp
, &dentry
);
230 * In the nfsd4_open() case, this may be held across
231 * subsequent open and delegation acquisition which may
232 * need to take the child's i_mutex:
234 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
235 dentry
= lookup_one_len(name
, dparent
, len
);
236 host_err
= PTR_ERR(dentry
);
239 if (nfsd_mountpoint(dentry
, exp
)) {
241 * We don't need the i_mutex after all. It's
242 * still possible we could open this (regular
243 * files can be mountpoints too), but the
244 * i_mutex is just there to prevent renames of
245 * something that we might be about to delegate,
246 * and a mountpoint won't be renamed:
249 if ((host_err
= nfsd_cross_mnt(rqstp
, &dentry
, &exp
))) {
255 *dentry_ret
= dentry
;
261 return nfserrno(host_err
);
265 * Look up one component of a pathname.
266 * N.B. After this call _both_ fhp and resfh need an fh_put
268 * If the lookup would cross a mountpoint, and the mounted filesystem
269 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
270 * accepted as it stands and the mounted directory is
271 * returned. Otherwise the covered directory is returned.
272 * NOTE: this mountpoint crossing is not supported properly by all
273 * clients and is explicitly disallowed for NFSv3
274 * NeilBrown <neilb@cse.unsw.edu.au>
277 nfsd_lookup(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, const char *name
,
278 unsigned int len
, struct svc_fh
*resfh
)
280 struct svc_export
*exp
;
281 struct dentry
*dentry
;
284 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_EXEC
);
287 err
= nfsd_lookup_dentry(rqstp
, fhp
, name
, len
, &exp
, &dentry
);
290 err
= check_nfsd_access(exp
, rqstp
);
294 * Note: we compose the file handle now, but as the
295 * dentry may be negative, it may need to be updated.
297 err
= fh_compose(resfh
, exp
, dentry
, fhp
);
298 if (!err
&& d_really_is_negative(dentry
))
307 * Commit metadata changes to stable storage.
310 commit_metadata(struct svc_fh
*fhp
)
312 struct inode
*inode
= d_inode(fhp
->fh_dentry
);
313 const struct export_operations
*export_ops
= inode
->i_sb
->s_export_op
;
315 if (!EX_ISSYNC(fhp
->fh_export
))
318 if (export_ops
->commit_metadata
)
319 return export_ops
->commit_metadata(inode
);
320 return sync_inode_metadata(inode
, 1);
324 * Go over the attributes and take care of the small differences between
325 * NFS semantics and what Linux expects.
328 nfsd_sanitize_attrs(struct inode
*inode
, struct iattr
*iap
)
330 /* sanitize the mode change */
331 if (iap
->ia_valid
& ATTR_MODE
) {
332 iap
->ia_mode
&= S_IALLUGO
;
333 iap
->ia_mode
|= (inode
->i_mode
& ~S_IALLUGO
);
336 /* Revoke setuid/setgid on chown */
337 if (!S_ISDIR(inode
->i_mode
) &&
338 ((iap
->ia_valid
& ATTR_UID
) || (iap
->ia_valid
& ATTR_GID
))) {
339 iap
->ia_valid
|= ATTR_KILL_PRIV
;
340 if (iap
->ia_valid
& ATTR_MODE
) {
341 /* we're setting mode too, just clear the s*id bits */
342 iap
->ia_mode
&= ~S_ISUID
;
343 if (iap
->ia_mode
& S_IXGRP
)
344 iap
->ia_mode
&= ~S_ISGID
;
346 /* set ATTR_KILL_* bits and let VFS handle it */
347 iap
->ia_valid
|= (ATTR_KILL_SUID
| ATTR_KILL_SGID
);
353 nfsd_get_write_access(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
356 struct inode
*inode
= d_inode(fhp
->fh_dentry
);
359 if (iap
->ia_size
< inode
->i_size
) {
362 err
= nfsd_permission(rqstp
, fhp
->fh_export
, fhp
->fh_dentry
,
363 NFSD_MAY_TRUNC
| NFSD_MAY_OWNER_OVERRIDE
);
368 host_err
= get_write_access(inode
);
372 host_err
= locks_verify_truncate(inode
, NULL
, iap
->ia_size
);
374 goto out_put_write_access
;
377 out_put_write_access
:
378 put_write_access(inode
);
380 return nfserrno(host_err
);
384 * Set various file attributes. After this call fhp needs an fh_put.
387 nfsd_setattr(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct iattr
*iap
,
388 int check_guard
, time_t guardtime
)
390 struct dentry
*dentry
;
392 int accmode
= NFSD_MAY_SATTR
;
396 bool get_write_count
;
397 bool size_change
= (iap
->ia_valid
& ATTR_SIZE
);
399 if (iap
->ia_valid
& (ATTR_ATIME
| ATTR_MTIME
| ATTR_SIZE
))
400 accmode
|= NFSD_MAY_WRITE
|NFSD_MAY_OWNER_OVERRIDE
;
401 if (iap
->ia_valid
& ATTR_SIZE
)
404 /* Callers that do fh_verify should do the fh_want_write: */
405 get_write_count
= !fhp
->fh_dentry
;
408 err
= fh_verify(rqstp
, fhp
, ftype
, accmode
);
411 if (get_write_count
) {
412 host_err
= fh_want_write(fhp
);
417 dentry
= fhp
->fh_dentry
;
418 inode
= d_inode(dentry
);
420 /* Ignore any mode updates on symlinks */
421 if (S_ISLNK(inode
->i_mode
))
422 iap
->ia_valid
&= ~ATTR_MODE
;
427 nfsd_sanitize_attrs(inode
, iap
);
429 if (check_guard
&& guardtime
!= inode
->i_ctime
.tv_sec
)
430 return nfserr_notsync
;
433 * The size case is special, it changes the file in addition to the
434 * attributes, and file systems don't expect it to be mixed with
435 * "random" attribute changes. We thus split out the size change
436 * into a separate call to ->setattr, and do the rest as a separate
440 err
= nfsd_get_write_access(rqstp
, fhp
, iap
);
448 * RFC5661, Section 18.30.4:
449 * Changing the size of a file with SETATTR indirectly
450 * changes the time_modify and change attributes.
452 * (and similar for the older RFCs)
454 struct iattr size_attr
= {
455 .ia_valid
= ATTR_SIZE
| ATTR_CTIME
| ATTR_MTIME
,
456 .ia_size
= iap
->ia_size
,
459 host_err
= notify_change(dentry
, &size_attr
, NULL
);
462 iap
->ia_valid
&= ~ATTR_SIZE
;
465 * Avoid the additional setattr call below if the only other
466 * attribute that the client sends is the mtime, as we update
467 * it as part of the size change above.
469 if ((iap
->ia_valid
& ~ATTR_MTIME
) == 0)
473 iap
->ia_valid
|= ATTR_CTIME
;
474 host_err
= notify_change(dentry
, iap
, NULL
);
479 put_write_access(inode
);
482 host_err
= commit_metadata(fhp
);
483 return nfserrno(host_err
);
486 #if defined(CONFIG_NFSD_V4)
488 * NFS junction information is stored in an extended attribute.
490 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
493 * nfsd4_is_junction - Test if an object could be an NFS junction
495 * @dentry: object to test
497 * Returns 1 if "dentry" appears to contain NFS junction information.
498 * Otherwise 0 is returned.
500 int nfsd4_is_junction(struct dentry
*dentry
)
502 struct inode
*inode
= d_inode(dentry
);
506 if (inode
->i_mode
& S_IXUGO
)
508 if (!(inode
->i_mode
& S_ISVTX
))
510 if (vfs_getxattr(dentry
, NFSD_JUNCTION_XATTR_NAME
, NULL
, 0) <= 0)
514 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
515 __be32
nfsd4_set_nfs4_label(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
516 struct xdr_netobj
*label
)
520 struct dentry
*dentry
;
522 error
= fh_verify(rqstp
, fhp
, 0 /* S_IFREG */, NFSD_MAY_SATTR
);
526 dentry
= fhp
->fh_dentry
;
528 inode_lock(d_inode(dentry
));
529 host_error
= security_inode_setsecctx(dentry
, label
->data
, label
->len
);
530 inode_unlock(d_inode(dentry
));
531 return nfserrno(host_error
);
534 __be32
nfsd4_set_nfs4_label(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
535 struct xdr_netobj
*label
)
537 return nfserr_notsupp
;
541 __be32
nfsd4_clone_file_range(struct file
*src
, u64 src_pos
, struct file
*dst
,
542 u64 dst_pos
, u64 count
)
544 return nfserrno(vfs_clone_file_range(src
, src_pos
, dst
, dst_pos
,
548 ssize_t
nfsd_copy_file_range(struct file
*src
, u64 src_pos
, struct file
*dst
,
549 u64 dst_pos
, u64 count
)
553 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
554 * thread and client rpc slot. The choice of 4MB is somewhat
555 * arbitrary. We might instead base this on r/wsize, or make it
556 * tunable, or use a time instead of a byte limit, or implement
557 * asynchronous copy. In theory a client could also recognize a
558 * limit like this and pipeline multiple COPY requests.
560 count
= min_t(u64
, count
, 1 << 22);
561 return vfs_copy_file_range(src
, src_pos
, dst
, dst_pos
, count
, 0);
564 __be32
nfsd4_vfs_fallocate(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
565 struct file
*file
, loff_t offset
, loff_t len
,
570 if (!S_ISREG(file_inode(file
)->i_mode
))
573 error
= vfs_fallocate(file
, flags
, offset
, len
);
575 error
= commit_metadata(fhp
);
577 return nfserrno(error
);
579 #endif /* defined(CONFIG_NFSD_V4) */
581 #ifdef CONFIG_NFSD_V3
583 * Check server access rights to a file system object
589 static struct accessmap nfs3_regaccess
[] = {
590 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
591 { NFS3_ACCESS_EXECUTE
, NFSD_MAY_EXEC
},
592 { NFS3_ACCESS_MODIFY
, NFSD_MAY_WRITE
|NFSD_MAY_TRUNC
},
593 { NFS3_ACCESS_EXTEND
, NFSD_MAY_WRITE
},
598 static struct accessmap nfs3_diraccess
[] = {
599 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
600 { NFS3_ACCESS_LOOKUP
, NFSD_MAY_EXEC
},
601 { NFS3_ACCESS_MODIFY
, NFSD_MAY_EXEC
|NFSD_MAY_WRITE
|NFSD_MAY_TRUNC
},
602 { NFS3_ACCESS_EXTEND
, NFSD_MAY_EXEC
|NFSD_MAY_WRITE
},
603 { NFS3_ACCESS_DELETE
, NFSD_MAY_REMOVE
},
608 static struct accessmap nfs3_anyaccess
[] = {
609 /* Some clients - Solaris 2.6 at least, make an access call
610 * to the server to check for access for things like /dev/null
611 * (which really, the server doesn't care about). So
612 * We provide simple access checking for them, looking
613 * mainly at mode bits, and we make sure to ignore read-only
616 { NFS3_ACCESS_READ
, NFSD_MAY_READ
},
617 { NFS3_ACCESS_EXECUTE
, NFSD_MAY_EXEC
},
618 { NFS3_ACCESS_MODIFY
, NFSD_MAY_WRITE
|NFSD_MAY_LOCAL_ACCESS
},
619 { NFS3_ACCESS_EXTEND
, NFSD_MAY_WRITE
|NFSD_MAY_LOCAL_ACCESS
},
625 nfsd_access(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, u32
*access
, u32
*supported
)
627 struct accessmap
*map
;
628 struct svc_export
*export
;
629 struct dentry
*dentry
;
630 u32 query
, result
= 0, sresult
= 0;
633 error
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_NOP
);
637 export
= fhp
->fh_export
;
638 dentry
= fhp
->fh_dentry
;
640 if (d_is_reg(dentry
))
641 map
= nfs3_regaccess
;
642 else if (d_is_dir(dentry
))
643 map
= nfs3_diraccess
;
645 map
= nfs3_anyaccess
;
649 for (; map
->access
; map
++) {
650 if (map
->access
& query
) {
653 sresult
|= map
->access
;
655 err2
= nfsd_permission(rqstp
, export
, dentry
, map
->how
);
658 result
|= map
->access
;
661 /* the following error codes just mean the access was not allowed,
662 * rather than an error occurred */
666 /* simply don't "or" in the access bit. */
676 *supported
= sresult
;
681 #endif /* CONFIG_NFSD_V3 */
683 static int nfsd_open_break_lease(struct inode
*inode
, int access
)
687 if (access
& NFSD_MAY_NOT_BREAK_LEASE
)
689 mode
= (access
& NFSD_MAY_WRITE
) ? O_WRONLY
: O_RDONLY
;
690 return break_lease(inode
, mode
| O_NONBLOCK
);
694 * Open an existing file or directory.
695 * The may_flags argument indicates the type of open (read/write/lock)
696 * and additional flags.
697 * N.B. After this call fhp needs an fh_put
700 nfsd_open(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, umode_t type
,
701 int may_flags
, struct file
**filp
)
706 int flags
= O_RDONLY
|O_LARGEFILE
;
710 validate_process_creds();
713 * If we get here, then the client has already done an "open",
714 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
715 * in case a chmod has now revoked permission.
717 * Arguably we should also allow the owner override for
718 * directories, but we never have and it doesn't seem to have
719 * caused anyone a problem. If we were to change this, note
720 * also that our filldir callbacks would need a variant of
721 * lookup_one_len that doesn't check permissions.
724 may_flags
|= NFSD_MAY_OWNER_OVERRIDE
;
725 err
= fh_verify(rqstp
, fhp
, type
, may_flags
);
729 path
.mnt
= fhp
->fh_export
->ex_path
.mnt
;
730 path
.dentry
= fhp
->fh_dentry
;
731 inode
= d_inode(path
.dentry
);
733 /* Disallow write access to files with the append-only bit set
734 * or any access when mandatory locking enabled
737 if (IS_APPEND(inode
) && (may_flags
& NFSD_MAY_WRITE
))
740 * We must ignore files (but only files) which might have mandatory
741 * locks on them because there is no way to know if the accesser has
744 if (S_ISREG((inode
)->i_mode
) && mandatory_lock(inode
))
750 host_err
= nfsd_open_break_lease(inode
, may_flags
);
751 if (host_err
) /* NOMEM or WOULDBLOCK */
754 if (may_flags
& NFSD_MAY_WRITE
) {
755 if (may_flags
& NFSD_MAY_READ
)
756 flags
= O_RDWR
|O_LARGEFILE
;
758 flags
= O_WRONLY
|O_LARGEFILE
;
761 file
= dentry_open(&path
, flags
, current_cred());
763 host_err
= PTR_ERR(file
);
767 host_err
= ima_file_check(file
, may_flags
);
773 if (may_flags
& NFSD_MAY_64BIT_COOKIE
)
774 file
->f_mode
|= FMODE_64BITHASH
;
776 file
->f_mode
|= FMODE_32BITHASH
;
780 err
= nfserrno(host_err
);
782 validate_process_creds();
787 nfsd_init_raparms(struct file
*file
)
789 struct inode
*inode
= file_inode(file
);
790 dev_t dev
= inode
->i_sb
->s_dev
;
791 ino_t ino
= inode
->i_ino
;
792 struct raparms
*ra
, **rap
, **frap
= NULL
;
795 struct raparm_hbucket
*rab
;
797 hash
= jhash_2words(dev
, ino
, 0xfeedbeef) & RAPARM_HASH_MASK
;
798 rab
= &raparm_hash
[hash
];
800 spin_lock(&rab
->pb_lock
);
801 for (rap
= &rab
->pb_head
; (ra
= *rap
); rap
= &ra
->p_next
) {
802 if (ra
->p_ino
== ino
&& ra
->p_dev
== dev
)
805 if (ra
->p_count
== 0)
808 depth
= nfsdstats
.ra_size
;
810 spin_unlock(&rab
->pb_lock
);
820 if (rap
!= &rab
->pb_head
) {
822 ra
->p_next
= rab
->pb_head
;
826 nfsdstats
.ra_depth
[depth
*10/nfsdstats
.ra_size
]++;
827 spin_unlock(&rab
->pb_lock
);
830 file
->f_ra
= ra
->p_ra
;
834 void nfsd_put_raparams(struct file
*file
, struct raparms
*ra
)
836 struct raparm_hbucket
*rab
= &raparm_hash
[ra
->p_hindex
];
838 spin_lock(&rab
->pb_lock
);
839 ra
->p_ra
= file
->f_ra
;
842 spin_unlock(&rab
->pb_lock
);
846 * Grab and keep cached pages associated with a file in the svc_rqst
847 * so that they can be passed to the network sendmsg/sendpage routines
848 * directly. They will be released after the sending has completed.
851 nfsd_splice_actor(struct pipe_inode_info
*pipe
, struct pipe_buffer
*buf
,
852 struct splice_desc
*sd
)
854 struct svc_rqst
*rqstp
= sd
->u
.data
;
855 struct page
**pp
= rqstp
->rq_next_page
;
856 struct page
*page
= buf
->page
;
861 if (rqstp
->rq_res
.page_len
== 0) {
863 put_page(*rqstp
->rq_next_page
);
864 *(rqstp
->rq_next_page
++) = page
;
865 rqstp
->rq_res
.page_base
= buf
->offset
;
866 rqstp
->rq_res
.page_len
= size
;
867 } else if (page
!= pp
[-1]) {
869 if (*rqstp
->rq_next_page
)
870 put_page(*rqstp
->rq_next_page
);
871 *(rqstp
->rq_next_page
++) = page
;
872 rqstp
->rq_res
.page_len
+= size
;
874 rqstp
->rq_res
.page_len
+= size
;
879 static int nfsd_direct_splice_actor(struct pipe_inode_info
*pipe
,
880 struct splice_desc
*sd
)
882 return __splice_from_pipe(pipe
, sd
, nfsd_splice_actor
);
885 static __be32
nfsd_finish_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
886 struct file
*file
, loff_t offset
,
887 unsigned long *count
, int host_err
)
890 nfsdstats
.io_read
+= host_err
;
892 fsnotify_access(file
);
893 trace_nfsd_read_io_done(rqstp
, fhp
, offset
, *count
);
896 trace_nfsd_read_err(rqstp
, fhp
, offset
, host_err
);
897 return nfserrno(host_err
);
901 __be32
nfsd_splice_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
902 struct file
*file
, loff_t offset
, unsigned long *count
)
904 struct splice_desc sd
= {
912 trace_nfsd_read_splice(rqstp
, fhp
, offset
, *count
);
913 rqstp
->rq_next_page
= rqstp
->rq_respages
+ 1;
914 host_err
= splice_direct_to_actor(file
, &sd
, nfsd_direct_splice_actor
);
915 return nfsd_finish_read(rqstp
, fhp
, file
, offset
, count
, host_err
);
918 __be32
nfsd_readv(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
919 struct file
*file
, loff_t offset
,
920 struct kvec
*vec
, int vlen
, unsigned long *count
)
922 struct iov_iter iter
;
925 trace_nfsd_read_vector(rqstp
, fhp
, offset
, *count
);
926 iov_iter_kvec(&iter
, READ
, vec
, vlen
, *count
);
927 host_err
= vfs_iter_read(file
, &iter
, &offset
, 0);
928 return nfsd_finish_read(rqstp
, fhp
, file
, offset
, count
, host_err
);
932 * Gathered writes: If another process is currently writing to the file,
933 * there's a high chance this is another nfsd (triggered by a bulk write
934 * from a client's biod). Rather than syncing the file with each write
935 * request, we sleep for 10 msec.
937 * I don't know if this roughly approximates C. Juszak's idea of
938 * gathered writes, but it's a nice and simple solution (IMHO), and it
941 * Note: we do this only in the NFSv2 case, since v3 and higher have a
942 * better tool (separate unstable writes and commits) for solving this
945 static int wait_for_concurrent_writes(struct file
*file
)
947 struct inode
*inode
= file_inode(file
);
948 static ino_t last_ino
;
949 static dev_t last_dev
;
952 if (atomic_read(&inode
->i_writecount
) > 1
953 || (last_ino
== inode
->i_ino
&& last_dev
== inode
->i_sb
->s_dev
)) {
954 dprintk("nfsd: write defer %d\n", task_pid_nr(current
));
956 dprintk("nfsd: write resume %d\n", task_pid_nr(current
));
959 if (inode
->i_state
& I_DIRTY
) {
960 dprintk("nfsd: write sync %d\n", task_pid_nr(current
));
961 err
= vfs_fsync(file
, 0);
963 last_ino
= inode
->i_ino
;
964 last_dev
= inode
->i_sb
->s_dev
;
969 nfsd_vfs_write(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct file
*file
,
970 loff_t offset
, struct kvec
*vec
, int vlen
,
971 unsigned long *cnt
, int stable
)
973 struct svc_export
*exp
;
974 struct iov_iter iter
;
979 unsigned int pflags
= current
->flags
;
982 trace_nfsd_write_opened(rqstp
, fhp
, offset
, *cnt
);
984 if (test_bit(RQ_LOCAL
, &rqstp
->rq_flags
))
986 * We want less throttling in balance_dirty_pages()
987 * and shrink_inactive_list() so that nfs to
988 * localhost doesn't cause nfsd to lock up due to all
989 * the client's dirty pages or its congested queue.
991 current
->flags
|= PF_LESS_THROTTLE
;
993 exp
= fhp
->fh_export
;
994 use_wgather
= (rqstp
->rq_vers
== 2) && EX_WGATHER(exp
);
997 stable
= NFS_UNSTABLE
;
999 if (stable
&& !use_wgather
)
1002 iov_iter_kvec(&iter
, WRITE
, vec
, vlen
, *cnt
);
1003 host_err
= vfs_iter_write(file
, &iter
, &pos
, flags
);
1006 nfsdstats
.io_write
+= *cnt
;
1007 fsnotify_modify(file
);
1009 if (stable
&& use_wgather
)
1010 host_err
= wait_for_concurrent_writes(file
);
1013 if (host_err
>= 0) {
1014 trace_nfsd_write_io_done(rqstp
, fhp
, offset
, *cnt
);
1017 trace_nfsd_write_err(rqstp
, fhp
, offset
, host_err
);
1018 nfserr
= nfserrno(host_err
);
1020 if (test_bit(RQ_LOCAL
, &rqstp
->rq_flags
))
1021 current_restore_flags(pflags
, PF_LESS_THROTTLE
);
1026 * Read data from a file. count must contain the requested read count
1027 * on entry. On return, *count contains the number of bytes actually read.
1028 * N.B. After this call fhp needs an fh_put
1030 __be32
nfsd_read(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1031 loff_t offset
, struct kvec
*vec
, int vlen
, unsigned long *count
)
1037 trace_nfsd_read_start(rqstp
, fhp
, offset
, *count
);
1038 err
= nfsd_open(rqstp
, fhp
, S_IFREG
, NFSD_MAY_READ
, &file
);
1042 ra
= nfsd_init_raparms(file
);
1044 if (file
->f_op
->splice_read
&& test_bit(RQ_SPLICE_OK
, &rqstp
->rq_flags
))
1045 err
= nfsd_splice_read(rqstp
, fhp
, file
, offset
, count
);
1047 err
= nfsd_readv(rqstp
, fhp
, file
, offset
, vec
, vlen
, count
);
1050 nfsd_put_raparams(file
, ra
);
1053 trace_nfsd_read_done(rqstp
, fhp
, offset
, *count
);
1059 * Write data to a file.
1060 * The stable flag requests synchronous writes.
1061 * N.B. After this call fhp needs an fh_put
1064 nfsd_write(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, loff_t offset
,
1065 struct kvec
*vec
, int vlen
, unsigned long *cnt
, int stable
)
1067 struct file
*file
= NULL
;
1070 trace_nfsd_write_start(rqstp
, fhp
, offset
, *cnt
);
1072 err
= nfsd_open(rqstp
, fhp
, S_IFREG
, NFSD_MAY_WRITE
, &file
);
1076 err
= nfsd_vfs_write(rqstp
, fhp
, file
, offset
, vec
, vlen
, cnt
, stable
);
1079 trace_nfsd_write_done(rqstp
, fhp
, offset
, *cnt
);
1083 #ifdef CONFIG_NFSD_V3
1085 * Commit all pending writes to stable storage.
1087 * Note: we only guarantee that data that lies within the range specified
1088 * by the 'offset' and 'count' parameters will be synced.
1090 * Unfortunately we cannot lock the file to make sure we return full WCC
1091 * data to the client, as locking happens lower down in the filesystem.
1094 nfsd_commit(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1095 loff_t offset
, unsigned long count
)
1098 loff_t end
= LLONG_MAX
;
1099 __be32 err
= nfserr_inval
;
1104 end
= offset
+ (loff_t
)count
- 1;
1109 err
= nfsd_open(rqstp
, fhp
, S_IFREG
,
1110 NFSD_MAY_WRITE
|NFSD_MAY_NOT_BREAK_LEASE
, &file
);
1113 if (EX_ISSYNC(fhp
->fh_export
)) {
1114 int err2
= vfs_fsync_range(file
, offset
, end
, 0);
1116 if (err2
!= -EINVAL
)
1117 err
= nfserrno(err2
);
1119 err
= nfserr_notsupp
;
1126 #endif /* CONFIG_NFSD_V3 */
1129 nfsd_create_setattr(struct svc_rqst
*rqstp
, struct svc_fh
*resfhp
,
1133 * Mode has already been set earlier in create:
1135 iap
->ia_valid
&= ~ATTR_MODE
;
1137 * Setting uid/gid works only for root. Irix appears to
1138 * send along the gid on create when it tries to implement
1139 * setgid directories via NFS:
1141 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID
))
1142 iap
->ia_valid
&= ~(ATTR_UID
|ATTR_GID
);
1144 return nfsd_setattr(rqstp
, resfhp
, iap
, 0, (time_t)0);
1145 /* Callers expect file metadata to be committed here */
1146 return nfserrno(commit_metadata(resfhp
));
1149 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1150 * setting size to 0 may fail for some specific file systems by the permission
1151 * checking which requires WRITE permission but the mode is 000.
1152 * we ignore the resizing(to 0) on the just new created file, since the size is
1153 * 0 after file created.
1155 * call this only after vfs_create() is called.
1158 nfsd_check_ignore_resizing(struct iattr
*iap
)
1160 if ((iap
->ia_valid
& ATTR_SIZE
) && (iap
->ia_size
== 0))
1161 iap
->ia_valid
&= ~ATTR_SIZE
;
1164 /* The parent directory should already be locked: */
1166 nfsd_create_locked(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1167 char *fname
, int flen
, struct iattr
*iap
,
1168 int type
, dev_t rdev
, struct svc_fh
*resfhp
)
1170 struct dentry
*dentry
, *dchild
;
1176 dentry
= fhp
->fh_dentry
;
1177 dirp
= d_inode(dentry
);
1179 dchild
= dget(resfhp
->fh_dentry
);
1180 if (!fhp
->fh_locked
) {
1181 WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n",
1187 err
= nfsd_permission(rqstp
, fhp
->fh_export
, dentry
, NFSD_MAY_CREATE
);
1191 if (!(iap
->ia_valid
& ATTR_MODE
))
1193 iap
->ia_mode
= (iap
->ia_mode
& S_IALLUGO
) | type
;
1199 host_err
= vfs_create(dirp
, dchild
, iap
->ia_mode
, true);
1201 nfsd_check_ignore_resizing(iap
);
1204 host_err
= vfs_mkdir(dirp
, dchild
, iap
->ia_mode
);
1205 if (!host_err
&& unlikely(d_unhashed(dchild
))) {
1207 d
= lookup_one_len(dchild
->d_name
.name
,
1209 dchild
->d_name
.len
);
1211 host_err
= PTR_ERR(d
);
1214 if (unlikely(d_is_negative(d
))) {
1216 err
= nfserr_serverfault
;
1219 dput(resfhp
->fh_dentry
);
1220 resfhp
->fh_dentry
= dget(d
);
1221 err
= fh_update(resfhp
);
1232 host_err
= vfs_mknod(dirp
, dchild
, iap
->ia_mode
, rdev
);
1235 printk(KERN_WARNING
"nfsd: bad file type %o in nfsd_create\n",
1242 err
= nfsd_create_setattr(rqstp
, resfhp
, iap
);
1245 * nfsd_create_setattr already committed the child. Transactional
1246 * filesystems had a chance to commit changes for both parent and
1247 * child simultaneously making the following commit_metadata a
1250 err2
= nfserrno(commit_metadata(fhp
));
1254 * Update the file handle to get the new inode info.
1257 err
= fh_update(resfhp
);
1263 err
= nfserrno(host_err
);
1268 * Create a filesystem object (regular, directory, special).
1269 * Note that the parent directory is left locked.
1271 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1274 nfsd_create(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1275 char *fname
, int flen
, struct iattr
*iap
,
1276 int type
, dev_t rdev
, struct svc_fh
*resfhp
)
1278 struct dentry
*dentry
, *dchild
= NULL
;
1282 if (isdotent(fname
, flen
))
1283 return nfserr_exist
;
1285 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_NOP
);
1289 dentry
= fhp
->fh_dentry
;
1291 host_err
= fh_want_write(fhp
);
1293 return nfserrno(host_err
);
1295 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1296 dchild
= lookup_one_len(fname
, dentry
, flen
);
1297 host_err
= PTR_ERR(dchild
);
1299 return nfserrno(host_err
);
1300 err
= fh_compose(resfhp
, fhp
->fh_export
, dchild
, fhp
);
1302 * We unconditionally drop our ref to dchild as fh_compose will have
1303 * already grabbed its own ref for it.
1308 return nfsd_create_locked(rqstp
, fhp
, fname
, flen
, iap
, type
,
1312 #ifdef CONFIG_NFSD_V3
1315 * NFSv3 and NFSv4 version of nfsd_create
1318 do_nfsd_create(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1319 char *fname
, int flen
, struct iattr
*iap
,
1320 struct svc_fh
*resfhp
, int createmode
, u32
*verifier
,
1321 bool *truncp
, bool *created
)
1323 struct dentry
*dentry
, *dchild
= NULL
;
1327 __u32 v_mtime
=0, v_atime
=0;
1333 if (isdotent(fname
, flen
))
1335 if (!(iap
->ia_valid
& ATTR_MODE
))
1337 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_EXEC
);
1341 dentry
= fhp
->fh_dentry
;
1342 dirp
= d_inode(dentry
);
1344 host_err
= fh_want_write(fhp
);
1348 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1351 * Compose the response file handle.
1353 dchild
= lookup_one_len(fname
, dentry
, flen
);
1354 host_err
= PTR_ERR(dchild
);
1358 /* If file doesn't exist, check for permissions to create one */
1359 if (d_really_is_negative(dchild
)) {
1360 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1365 err
= fh_compose(resfhp
, fhp
->fh_export
, dchild
, fhp
);
1369 if (nfsd_create_is_exclusive(createmode
)) {
1370 /* solaris7 gets confused (bugid 4218508) if these have
1371 * the high bit set, so just clear the high bits. If this is
1372 * ever changed to use different attrs for storing the
1373 * verifier, then do_open_lookup() will also need to be fixed
1376 v_mtime
= verifier
[0]&0x7fffffff;
1377 v_atime
= verifier
[1]&0x7fffffff;
1380 if (d_really_is_positive(dchild
)) {
1383 switch (createmode
) {
1384 case NFS3_CREATE_UNCHECKED
:
1385 if (! d_is_reg(dchild
))
1388 /* in nfsv4, we need to treat this case a little
1389 * differently. we don't want to truncate the
1390 * file now; this would be wrong if the OPEN
1391 * fails for some other reason. furthermore,
1392 * if the size is nonzero, we should ignore it
1393 * according to spec!
1395 *truncp
= (iap
->ia_valid
& ATTR_SIZE
) && !iap
->ia_size
;
1398 iap
->ia_valid
&= ATTR_SIZE
;
1402 case NFS3_CREATE_EXCLUSIVE
:
1403 if ( d_inode(dchild
)->i_mtime
.tv_sec
== v_mtime
1404 && d_inode(dchild
)->i_atime
.tv_sec
== v_atime
1405 && d_inode(dchild
)->i_size
== 0 ) {
1411 case NFS4_CREATE_EXCLUSIVE4_1
:
1412 if ( d_inode(dchild
)->i_mtime
.tv_sec
== v_mtime
1413 && d_inode(dchild
)->i_atime
.tv_sec
== v_atime
1414 && d_inode(dchild
)->i_size
== 0 ) {
1420 case NFS3_CREATE_GUARDED
:
1427 host_err
= vfs_create(dirp
, dchild
, iap
->ia_mode
, true);
1435 nfsd_check_ignore_resizing(iap
);
1437 if (nfsd_create_is_exclusive(createmode
)) {
1438 /* Cram the verifier into atime/mtime */
1439 iap
->ia_valid
= ATTR_MTIME
|ATTR_ATIME
1440 | ATTR_MTIME_SET
|ATTR_ATIME_SET
;
1441 /* XXX someone who knows this better please fix it for nsec */
1442 iap
->ia_mtime
.tv_sec
= v_mtime
;
1443 iap
->ia_atime
.tv_sec
= v_atime
;
1444 iap
->ia_mtime
.tv_nsec
= 0;
1445 iap
->ia_atime
.tv_nsec
= 0;
1449 err
= nfsd_create_setattr(rqstp
, resfhp
, iap
);
1452 * nfsd_create_setattr already committed the child
1453 * (and possibly also the parent).
1456 err
= nfserrno(commit_metadata(fhp
));
1459 * Update the filehandle to get the new inode info.
1462 err
= fh_update(resfhp
);
1466 if (dchild
&& !IS_ERR(dchild
))
1472 err
= nfserrno(host_err
);
1475 #endif /* CONFIG_NFSD_V3 */
1478 * Read a symlink. On entry, *lenp must contain the maximum path length that
1479 * fits into the buffer. On return, it contains the true length.
1480 * N.B. After this call fhp needs an fh_put
1483 nfsd_readlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, char *buf
, int *lenp
)
1488 DEFINE_DELAYED_CALL(done
);
1491 err
= fh_verify(rqstp
, fhp
, S_IFLNK
, NFSD_MAY_NOP
);
1495 path
.mnt
= fhp
->fh_export
->ex_path
.mnt
;
1496 path
.dentry
= fhp
->fh_dentry
;
1498 if (unlikely(!d_is_symlink(path
.dentry
)))
1499 return nfserr_inval
;
1503 link
= vfs_get_link(path
.dentry
, &done
);
1505 return nfserrno(PTR_ERR(link
));
1510 memcpy(buf
, link
, *lenp
);
1511 do_delayed_call(&done
);
1516 * Create a symlink and look up its inode
1517 * N.B. After this call _both_ fhp and resfhp need an fh_put
1520 nfsd_symlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
,
1521 char *fname
, int flen
,
1523 struct svc_fh
*resfhp
)
1525 struct dentry
*dentry
, *dnew
;
1530 if (!flen
|| path
[0] == '\0')
1533 if (isdotent(fname
, flen
))
1536 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1540 host_err
= fh_want_write(fhp
);
1545 dentry
= fhp
->fh_dentry
;
1546 dnew
= lookup_one_len(fname
, dentry
, flen
);
1547 host_err
= PTR_ERR(dnew
);
1551 host_err
= vfs_symlink(d_inode(dentry
), dnew
, path
);
1552 err
= nfserrno(host_err
);
1554 err
= nfserrno(commit_metadata(fhp
));
1559 cerr
= fh_compose(resfhp
, fhp
->fh_export
, dnew
, fhp
);
1561 if (err
==0) err
= cerr
;
1566 err
= nfserrno(host_err
);
1572 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1575 nfsd_link(struct svc_rqst
*rqstp
, struct svc_fh
*ffhp
,
1576 char *name
, int len
, struct svc_fh
*tfhp
)
1578 struct dentry
*ddir
, *dnew
, *dold
;
1583 err
= fh_verify(rqstp
, ffhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1586 err
= fh_verify(rqstp
, tfhp
, 0, NFSD_MAY_NOP
);
1590 if (d_is_dir(tfhp
->fh_dentry
))
1596 if (isdotent(name
, len
))
1599 host_err
= fh_want_write(tfhp
);
1601 err
= nfserrno(host_err
);
1605 fh_lock_nested(ffhp
, I_MUTEX_PARENT
);
1606 ddir
= ffhp
->fh_dentry
;
1607 dirp
= d_inode(ddir
);
1609 dnew
= lookup_one_len(name
, ddir
, len
);
1610 host_err
= PTR_ERR(dnew
);
1614 dold
= tfhp
->fh_dentry
;
1617 if (d_really_is_negative(dold
))
1619 host_err
= vfs_link(dold
, dirp
, dnew
, NULL
);
1621 err
= nfserrno(commit_metadata(ffhp
));
1623 err
= nfserrno(commit_metadata(tfhp
));
1625 if (host_err
== -EXDEV
&& rqstp
->rq_vers
== 2)
1628 err
= nfserrno(host_err
);
1634 fh_drop_write(tfhp
);
1639 err
= nfserrno(host_err
);
1645 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1648 nfsd_rename(struct svc_rqst
*rqstp
, struct svc_fh
*ffhp
, char *fname
, int flen
,
1649 struct svc_fh
*tfhp
, char *tname
, int tlen
)
1651 struct dentry
*fdentry
, *tdentry
, *odentry
, *ndentry
, *trap
;
1652 struct inode
*fdir
, *tdir
;
1656 err
= fh_verify(rqstp
, ffhp
, S_IFDIR
, NFSD_MAY_REMOVE
);
1659 err
= fh_verify(rqstp
, tfhp
, S_IFDIR
, NFSD_MAY_CREATE
);
1663 fdentry
= ffhp
->fh_dentry
;
1664 fdir
= d_inode(fdentry
);
1666 tdentry
= tfhp
->fh_dentry
;
1667 tdir
= d_inode(tdentry
);
1670 if (!flen
|| isdotent(fname
, flen
) || !tlen
|| isdotent(tname
, tlen
))
1673 host_err
= fh_want_write(ffhp
);
1675 err
= nfserrno(host_err
);
1679 /* cannot use fh_lock as we need deadlock protective ordering
1680 * so do it by hand */
1681 trap
= lock_rename(tdentry
, fdentry
);
1682 ffhp
->fh_locked
= tfhp
->fh_locked
= true;
1686 odentry
= lookup_one_len(fname
, fdentry
, flen
);
1687 host_err
= PTR_ERR(odentry
);
1688 if (IS_ERR(odentry
))
1692 if (d_really_is_negative(odentry
))
1695 if (odentry
== trap
)
1698 ndentry
= lookup_one_len(tname
, tdentry
, tlen
);
1699 host_err
= PTR_ERR(ndentry
);
1700 if (IS_ERR(ndentry
))
1702 host_err
= -ENOTEMPTY
;
1703 if (ndentry
== trap
)
1707 if (ffhp
->fh_export
->ex_path
.mnt
!= tfhp
->fh_export
->ex_path
.mnt
)
1709 if (ffhp
->fh_export
->ex_path
.dentry
!= tfhp
->fh_export
->ex_path
.dentry
)
1712 host_err
= vfs_rename(fdir
, odentry
, tdir
, ndentry
, NULL
, 0);
1714 host_err
= commit_metadata(tfhp
);
1716 host_err
= commit_metadata(ffhp
);
1723 err
= nfserrno(host_err
);
1725 * We cannot rely on fh_unlock on the two filehandles,
1726 * as that would do the wrong thing if the two directories
1727 * were the same, so again we do it by hand.
1729 fill_post_wcc(ffhp
);
1730 fill_post_wcc(tfhp
);
1731 unlock_rename(tdentry
, fdentry
);
1732 ffhp
->fh_locked
= tfhp
->fh_locked
= false;
1733 fh_drop_write(ffhp
);
1740 * Unlink a file or directory
1741 * N.B. After this call fhp needs an fh_put
1744 nfsd_unlink(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, int type
,
1745 char *fname
, int flen
)
1747 struct dentry
*dentry
, *rdentry
;
1753 if (!flen
|| isdotent(fname
, flen
))
1755 err
= fh_verify(rqstp
, fhp
, S_IFDIR
, NFSD_MAY_REMOVE
);
1759 host_err
= fh_want_write(fhp
);
1763 fh_lock_nested(fhp
, I_MUTEX_PARENT
);
1764 dentry
= fhp
->fh_dentry
;
1765 dirp
= d_inode(dentry
);
1767 rdentry
= lookup_one_len(fname
, dentry
, flen
);
1768 host_err
= PTR_ERR(rdentry
);
1769 if (IS_ERR(rdentry
))
1772 if (d_really_is_negative(rdentry
)) {
1779 type
= d_inode(rdentry
)->i_mode
& S_IFMT
;
1781 if (type
!= S_IFDIR
)
1782 host_err
= vfs_unlink(dirp
, rdentry
, NULL
);
1784 host_err
= vfs_rmdir(dirp
, rdentry
);
1786 host_err
= commit_metadata(fhp
);
1790 err
= nfserrno(host_err
);
1796 * We do this buffering because we must not call back into the file
1797 * system's ->lookup() method from the filldir callback. That may well
1798 * deadlock a number of file systems.
1800 * This is based heavily on the implementation of same in XFS.
1802 struct buffered_dirent
{
1806 unsigned int d_type
;
1810 struct readdir_data
{
1811 struct dir_context ctx
;
1817 static int nfsd_buffered_filldir(struct dir_context
*ctx
, const char *name
,
1818 int namlen
, loff_t offset
, u64 ino
,
1819 unsigned int d_type
)
1821 struct readdir_data
*buf
=
1822 container_of(ctx
, struct readdir_data
, ctx
);
1823 struct buffered_dirent
*de
= (void *)(buf
->dirent
+ buf
->used
);
1824 unsigned int reclen
;
1826 reclen
= ALIGN(sizeof(struct buffered_dirent
) + namlen
, sizeof(u64
));
1827 if (buf
->used
+ reclen
> PAGE_SIZE
) {
1832 de
->namlen
= namlen
;
1833 de
->offset
= offset
;
1835 de
->d_type
= d_type
;
1836 memcpy(de
->name
, name
, namlen
);
1837 buf
->used
+= reclen
;
1842 static __be32
nfsd_buffered_readdir(struct file
*file
, nfsd_filldir_t func
,
1843 struct readdir_cd
*cdp
, loff_t
*offsetp
)
1845 struct buffered_dirent
*de
;
1849 struct readdir_data buf
= {
1850 .ctx
.actor
= nfsd_buffered_filldir
,
1851 .dirent
= (void *)__get_free_page(GFP_KERNEL
)
1855 return nfserrno(-ENOMEM
);
1860 unsigned int reclen
;
1862 cdp
->err
= nfserr_eof
; /* will be cleared on successful read */
1866 host_err
= iterate_dir(file
, &buf
.ctx
);
1878 de
= (struct buffered_dirent
*)buf
.dirent
;
1880 offset
= de
->offset
;
1882 if (func(cdp
, de
->name
, de
->namlen
, de
->offset
,
1883 de
->ino
, de
->d_type
))
1886 if (cdp
->err
!= nfs_ok
)
1889 reclen
= ALIGN(sizeof(*de
) + de
->namlen
,
1892 de
= (struct buffered_dirent
*)((char *)de
+ reclen
);
1894 if (size
> 0) /* We bailed out early */
1897 offset
= vfs_llseek(file
, 0, SEEK_CUR
);
1900 free_page((unsigned long)(buf
.dirent
));
1903 return nfserrno(host_err
);
1910 * Read entries from a directory.
1911 * The NFSv3/4 verifier we ignore for now.
1914 nfsd_readdir(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, loff_t
*offsetp
,
1915 struct readdir_cd
*cdp
, nfsd_filldir_t func
)
1919 loff_t offset
= *offsetp
;
1920 int may_flags
= NFSD_MAY_READ
;
1922 /* NFSv2 only supports 32 bit cookies */
1923 if (rqstp
->rq_vers
> 2)
1924 may_flags
|= NFSD_MAY_64BIT_COOKIE
;
1926 err
= nfsd_open(rqstp
, fhp
, S_IFDIR
, may_flags
, &file
);
1930 offset
= vfs_llseek(file
, offset
, SEEK_SET
);
1932 err
= nfserrno((int)offset
);
1936 err
= nfsd_buffered_readdir(file
, func
, cdp
, offsetp
);
1938 if (err
== nfserr_eof
|| err
== nfserr_toosmall
)
1939 err
= nfs_ok
; /* can still be found in ->err */
1947 * Get file system stats
1948 * N.B. After this call fhp needs an fh_put
1951 nfsd_statfs(struct svc_rqst
*rqstp
, struct svc_fh
*fhp
, struct kstatfs
*stat
, int access
)
1955 err
= fh_verify(rqstp
, fhp
, 0, NFSD_MAY_NOP
| access
);
1957 struct path path
= {
1958 .mnt
= fhp
->fh_export
->ex_path
.mnt
,
1959 .dentry
= fhp
->fh_dentry
,
1961 if (vfs_statfs(&path
, stat
))
1967 static int exp_rdonly(struct svc_rqst
*rqstp
, struct svc_export
*exp
)
1969 return nfsexp_flags(rqstp
, exp
) & NFSEXP_READONLY
;
1973 * Check for a user's access permissions to this inode.
1976 nfsd_permission(struct svc_rqst
*rqstp
, struct svc_export
*exp
,
1977 struct dentry
*dentry
, int acc
)
1979 struct inode
*inode
= d_inode(dentry
);
1982 if ((acc
& NFSD_MAY_MASK
) == NFSD_MAY_NOP
)
1985 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
1987 (acc
& NFSD_MAY_READ
)? " read" : "",
1988 (acc
& NFSD_MAY_WRITE
)? " write" : "",
1989 (acc
& NFSD_MAY_EXEC
)? " exec" : "",
1990 (acc
& NFSD_MAY_SATTR
)? " sattr" : "",
1991 (acc
& NFSD_MAY_TRUNC
)? " trunc" : "",
1992 (acc
& NFSD_MAY_LOCK
)? " lock" : "",
1993 (acc
& NFSD_MAY_OWNER_OVERRIDE
)? " owneroverride" : "",
1995 IS_IMMUTABLE(inode
)? " immut" : "",
1996 IS_APPEND(inode
)? " append" : "",
1997 __mnt_is_readonly(exp
->ex_path
.mnt
)? " ro" : "");
1998 dprintk(" owner %d/%d user %d/%d\n",
1999 inode
->i_uid
, inode
->i_gid
, current_fsuid(), current_fsgid());
2002 /* Normally we reject any write/sattr etc access on a read-only file
2003 * system. But if it is IRIX doing check on write-access for a
2004 * device special file, we ignore rofs.
2006 if (!(acc
& NFSD_MAY_LOCAL_ACCESS
))
2007 if (acc
& (NFSD_MAY_WRITE
| NFSD_MAY_SATTR
| NFSD_MAY_TRUNC
)) {
2008 if (exp_rdonly(rqstp
, exp
) ||
2009 __mnt_is_readonly(exp
->ex_path
.mnt
))
2011 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode
))
2014 if ((acc
& NFSD_MAY_TRUNC
) && IS_APPEND(inode
))
2017 if (acc
& NFSD_MAY_LOCK
) {
2018 /* If we cannot rely on authentication in NLM requests,
2019 * just allow locks, otherwise require read permission, or
2022 if (exp
->ex_flags
& NFSEXP_NOAUTHNLM
)
2025 acc
= NFSD_MAY_READ
| NFSD_MAY_OWNER_OVERRIDE
;
2028 * The file owner always gets access permission for accesses that
2029 * would normally be checked at open time. This is to make
2030 * file access work even when the client has done a fchmod(fd, 0).
2032 * However, `cp foo bar' should fail nevertheless when bar is
2033 * readonly. A sensible way to do this might be to reject all
2034 * attempts to truncate a read-only file, because a creat() call
2035 * always implies file truncation.
2036 * ... but this isn't really fair. A process may reasonably call
2037 * ftruncate on an open file descriptor on a file with perm 000.
2038 * We must trust the client to do permission checking - using "ACCESS"
2041 if ((acc
& NFSD_MAY_OWNER_OVERRIDE
) &&
2042 uid_eq(inode
->i_uid
, current_fsuid()))
2045 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2046 err
= inode_permission(inode
, acc
& (MAY_READ
|MAY_WRITE
|MAY_EXEC
));
2048 /* Allow read access to binaries even when mode 111 */
2049 if (err
== -EACCES
&& S_ISREG(inode
->i_mode
) &&
2050 (acc
== (NFSD_MAY_READ
| NFSD_MAY_OWNER_OVERRIDE
) ||
2051 acc
== (NFSD_MAY_READ
| NFSD_MAY_READ_IF_EXEC
)))
2052 err
= inode_permission(inode
, MAY_EXEC
);
2054 return err
? nfserrno(err
) : 0;
2058 nfsd_racache_shutdown(void)
2060 struct raparms
*raparm
, *last_raparm
;
2063 dprintk("nfsd: freeing readahead buffers.\n");
2065 for (i
= 0; i
< RAPARM_HASH_SIZE
; i
++) {
2066 raparm
= raparm_hash
[i
].pb_head
;
2068 last_raparm
= raparm
;
2069 raparm
= raparm
->p_next
;
2072 raparm_hash
[i
].pb_head
= NULL
;
2076 * Initialize readahead param cache
2079 nfsd_racache_init(int cache_size
)
2084 struct raparms
**raparm
= NULL
;
2087 if (raparm_hash
[0].pb_head
)
2089 nperbucket
= DIV_ROUND_UP(cache_size
, RAPARM_HASH_SIZE
);
2090 nperbucket
= max(2, nperbucket
);
2091 cache_size
= nperbucket
* RAPARM_HASH_SIZE
;
2093 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size
);
2095 for (i
= 0; i
< RAPARM_HASH_SIZE
; i
++) {
2096 spin_lock_init(&raparm_hash
[i
].pb_lock
);
2098 raparm
= &raparm_hash
[i
].pb_head
;
2099 for (j
= 0; j
< nperbucket
; j
++) {
2100 *raparm
= kzalloc(sizeof(struct raparms
), GFP_KERNEL
);
2103 raparm
= &(*raparm
)->p_next
;
2108 nfsdstats
.ra_size
= cache_size
;
2112 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2113 nfsd_racache_shutdown();