1 /* $NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad Exp $ */
4 * Copyright (c) 2005 The NetBSD Foundation, Inc.
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
20 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
21 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
22 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
34 * Efficient memory file system supporting functions.
36 #include <sys/cdefs.h>
38 #include <sys/kernel.h>
39 #include <sys/param.h>
40 #include <sys/namei.h>
43 #include <sys/spinlock2.h>
45 #include <sys/systm.h>
46 #include <sys/vnode.h>
47 #include <sys/vmmeter.h>
49 #include <sys/mplock2.h>
52 #include <vm/vm_object.h>
53 #include <vm/vm_page.h>
54 #include <vm/vm_pager.h>
55 #include <vm/vm_extern.h>
57 #include <vfs/tmpfs/tmpfs.h>
58 #include <vfs/tmpfs/tmpfs_fifoops.h>
59 #include <vfs/tmpfs/tmpfs_vnops.h>
61 static ino_t t_ino
= 2;
62 static struct spinlock ino_lock
;
63 static ino_t
tmpfs_fetch_ino(void);
65 /* --------------------------------------------------------------------- */
68 * Allocates a new node of type 'type' inside the 'tmp' mount point, with
69 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode',
70 * using the credentials of the process 'p'.
72 * If the node type is set to 'VDIR', then the parent parameter must point
73 * to the parent directory of the node being created. It may only be NULL
74 * while allocating the root node.
76 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter
77 * specifies the device the node represents.
79 * If the node type is set to 'VLNK', then the parameter target specifies
80 * the file name of the target file for the symbolic link that is being
83 * Note that new nodes are retrieved from the available list if it has
84 * items or, if it is empty, from the node pool as long as there is enough
85 * space to create them.
87 * Returns zero on success or an appropriate error code on failure.
90 tmpfs_alloc_node(struct tmpfs_mount
*tmp
, enum vtype type
,
91 uid_t uid
, gid_t gid
, mode_t mode
, struct tmpfs_node
*parent
,
92 char *target
, int rmajor
, int rminor
, struct tmpfs_node
**node
)
94 struct tmpfs_node
*nnode
;
98 /* If the root directory of the 'tmp' file system is not yet
99 * allocated, this must be the request to do it. */
100 KKASSERT(IMPLIES(tmp
->tm_root
== NULL
, parent
== NULL
&& type
== VDIR
));
102 KKASSERT(IFF(type
== VLNK
, target
!= NULL
));
103 KKASSERT(IFF(type
== VBLK
|| type
== VCHR
, rmajor
!= VNOVAL
));
105 if (tmp
->tm_nodes_inuse
> tmp
->tm_nodes_max
)
108 nnode
= (struct tmpfs_node
*)objcache_get(tmp
->tm_node_pool
, M_WAITOK
);
110 /* Generic initialization. */
111 nnode
->tn_type
= type
;
113 nnode
->tn_ctime
= nnode
->tn_mtime
= nnode
->tn_atime
115 nnode
->tn_ctimensec
= nnode
->tn_mtimensec
= nnode
->tn_atimensec
119 nnode
->tn_mode
= mode
;
120 nnode
->tn_id
= tmpfs_fetch_ino();
122 /* Type-specific initialization. */
123 switch (nnode
->tn_type
) {
126 rdev
= makeudev(rmajor
, rminor
);
127 if (rdev
== NOUDEV
) {
130 nnode
->tn_rdev
= rdev
;
134 TAILQ_INIT(&nnode
->tn_dir
.tn_dirhead
);
135 KKASSERT(parent
!= nnode
);
136 KKASSERT(IMPLIES(parent
== NULL
, tmp
->tm_root
== NULL
));
137 nnode
->tn_dir
.tn_parent
= parent
;
138 nnode
->tn_dir
.tn_readdir_lastn
= 0;
139 nnode
->tn_dir
.tn_readdir_lastp
= NULL
;
143 TMPFS_NODE_LOCK(parent
);
145 TMPFS_NODE_UNLOCK(parent
);
155 KKASSERT((strlen(target
) +1) < MAXPATHLEN
);
156 nnode
->tn_size
= strlen(target
);
157 nnode
->tn_link
= kmalloc(nnode
->tn_size
+ 1, M_TMPFSNAME
,
159 bcopy(target
, nnode
->tn_link
, nnode
->tn_size
);
160 nnode
->tn_link
[nnode
->tn_size
] = '\0';
164 nnode
->tn_reg
.tn_aobj
=
165 vm_pager_allocate(OBJT_SWAP
, NULL
, 0, VM_PROT_DEFAULT
, 0);
166 nnode
->tn_reg
.tn_aobj_pages
= 0;
171 panic("tmpfs_alloc_node: type %p %d", nnode
, (int)nnode
->tn_type
);
174 TMPFS_NODE_LOCK(nnode
);
176 LIST_INSERT_HEAD(&tmp
->tm_nodes_used
, nnode
, tn_entries
);
177 tmp
->tm_nodes_inuse
++;
179 TMPFS_NODE_UNLOCK(nnode
);
185 /* --------------------------------------------------------------------- */
188 * Destroys the node pointed to by node from the file system 'tmp'.
189 * If the node does not belong to the given mount point, the results are
192 * If the node references a directory; no entries are allowed because
193 * their removal could need a recursive algorithm, something forbidden in
194 * kernel space. Furthermore, there is not need to provide such
195 * functionality (recursive removal) because the only primitives offered
196 * to the user are the removal of empty directories and the deletion of
199 * Note that nodes are not really deleted; in fact, when a node has been
200 * allocated, it cannot be deleted during the whole life of the file
201 * system. Instead, they are moved to the available list and remain there
205 tmpfs_free_node(struct tmpfs_mount
*tmp
, struct tmpfs_node
*node
)
210 TMPFS_ASSERT_ELOCKED(node
);
211 KKASSERT(node
->tn_vnode
== NULL
);
212 KKASSERT((node
->tn_vpstate
& TMPFS_VNODE_ALLOCATING
) == 0);
216 LIST_REMOVE(node
, tn_entries
);
217 tmp
->tm_nodes_inuse
--;
219 TMPFS_NODE_UNLOCK(node
);
221 switch (node
->tn_type
) {
223 /* Do not do anything. VNON is provided to let the
224 * allocation routine clean itself easily by avoiding
225 * duplicating code in it. */
234 * The parent link can be NULL if this is the root
239 KKASSERT(node
->tn_dir
.tn_parent
|| node
== tmp
->tm_root
);
240 if (node
->tn_dir
.tn_parent
) {
241 TMPFS_NODE_LOCK(node
->tn_dir
.tn_parent
);
242 node
->tn_dir
.tn_parent
->tn_links
--;
245 * If the parent directory has no more links and
246 * no vnode ref nothing is going to come along
247 * and clean it up unless we do it here.
249 if (node
->tn_dir
.tn_parent
->tn_links
== 0 &&
250 node
->tn_dir
.tn_parent
->tn_vnode
== NULL
) {
251 tmpfs_free_node(tmp
, node
->tn_dir
.tn_parent
);
252 /* eats parent lock */
254 TMPFS_NODE_UNLOCK(node
->tn_dir
.tn_parent
);
256 node
->tn_dir
.tn_parent
= NULL
;
260 * If the root node is being destroyed don't leave a
261 * dangling pointer in tmpfs_mount.
263 if (node
== tmp
->tm_root
)
272 kfree(node
->tn_link
, M_TMPFSNAME
);
273 node
->tn_link
= NULL
;
277 if (node
->tn_reg
.tn_aobj
!= NULL
)
278 vm_pager_deallocate(node
->tn_reg
.tn_aobj
);
279 node
->tn_reg
.tn_aobj
= NULL
;
280 pages
= node
->tn_reg
.tn_aobj_pages
;
284 panic("tmpfs_free_node: type %p %d", node
, (int)node
->tn_type
);
288 * Clean up fields for the next allocation. The objcache only ctors
291 tmpfs_node_ctor(node
, NULL
, 0);
292 objcache_put(tmp
->tm_node_pool
, node
);
293 /* node is now invalid */
296 tmp
->tm_pages_used
-= pages
;
300 /* --------------------------------------------------------------------- */
303 * Allocates a new directory entry for the node node with a name of name.
304 * The new directory entry is returned in *de.
306 * The link count of node is increased by one to reflect the new object
309 * Returns zero on success or an appropriate error code on failure.
312 tmpfs_alloc_dirent(struct tmpfs_mount
*tmp
, struct tmpfs_node
*node
,
313 const char *name
, uint16_t len
, struct tmpfs_dirent
**de
)
315 struct tmpfs_dirent
*nde
;
318 nde
= (struct tmpfs_dirent
*)objcache_get(tmp
->tm_dirent_pool
, M_WAITOK
);
319 nde
->td_name
= kmalloc(len
+ 1, M_TMPFSNAME
, M_WAITOK
);
320 nde
->td_namelen
= len
;
321 bcopy(name
, nde
->td_name
, len
);
322 nde
->td_name
[len
] = '\0';
326 TMPFS_NODE_LOCK(node
);
328 TMPFS_NODE_UNLOCK(node
);
335 /* --------------------------------------------------------------------- */
338 * Frees a directory entry. It is the caller's responsibility to destroy
339 * the node referenced by it if needed.
341 * The link count of node is decreased by one to reflect the removal of an
342 * object that referenced it. This only happens if 'node_exists' is true;
343 * otherwise the function will not access the node referred to by the
344 * directory entry, as it may already have been released from the outside.
347 tmpfs_free_dirent(struct tmpfs_mount
*tmp
, struct tmpfs_dirent
*de
)
349 struct tmpfs_node
*node
;
353 TMPFS_NODE_LOCK(node
);
354 TMPFS_ASSERT_ELOCKED(node
);
355 KKASSERT(node
->tn_links
> 0);
357 TMPFS_NODE_UNLOCK(node
);
359 kfree(de
->td_name
, M_TMPFSNAME
);
363 objcache_put(tmp
->tm_dirent_pool
, de
);
366 /* --------------------------------------------------------------------- */
369 * Allocates a new vnode for the node node or returns a new reference to
370 * an existing one if the node had already a vnode referencing it. The
371 * resulting locked vnode is returned in *vpp.
373 * Returns zero on success or an appropriate error code on failure.
376 tmpfs_alloc_vp(struct mount
*mp
, struct tmpfs_node
*node
, int lkflag
,
383 TMPFS_NODE_LOCK(node
);
384 if ((vp
= node
->tn_vnode
) != NULL
) {
385 KKASSERT((node
->tn_vpstate
& TMPFS_VNODE_DOOMED
) == 0);
386 TMPFS_NODE_UNLOCK(node
);
387 (void) vget(vp
, lkflag
| LK_EXCLUSIVE
| LK_RETRY
);
390 * Make sure the vnode is still there after
391 * getting the interlock to avoid racing a free.
393 if (node
->tn_vnode
== NULL
|| node
->tn_vnode
!= vp
) {
402 * This should never happen.
404 if (node
->tn_vpstate
& TMPFS_VNODE_DOOMED
) {
405 TMPFS_NODE_UNLOCK(node
);
412 * otherwise lock the vp list while we call getnewvnode
413 * since that can block.
415 if (node
->tn_vpstate
& TMPFS_VNODE_ALLOCATING
) {
416 node
->tn_vpstate
|= TMPFS_VNODE_WANT
;
417 error
= tsleep((caddr_t
) &node
->tn_vpstate
,
418 PINTERLOCKED
| PCATCH
, "tmpfs_alloc_vp", 0);
419 TMPFS_NODE_UNLOCK(node
);
425 node
->tn_vpstate
|= TMPFS_VNODE_ALLOCATING
;
427 TMPFS_NODE_UNLOCK(node
);
429 /* Get a new vnode and associate it with our node. */
430 error
= getnewvnode(VT_TMPFS
, mp
, &vp
, VLKTIMEOUT
, LK_CANRECURSE
);
433 KKASSERT(vp
!= NULL
);
436 vp
->v_type
= node
->tn_type
;
438 /* Type-specific initialization. */
439 switch (node
->tn_type
) {
447 vinitvmio(vp
, node
->tn_size
);
450 if (node
->tn_size
>= vp
->v_mount
->mnt_maxsymlinklen
)
451 vinitvmio(vp
, node
->tn_size
);
454 vp
->v_ops
= &mp
->mnt_vn_fifo_ops
;
457 vinitvmio(vp
, node
->tn_size
);
461 panic("tmpfs_alloc_vp: type %p %d", node
, (int)node
->tn_type
);
467 TMPFS_NODE_LOCK(node
);
469 KKASSERT(node
->tn_vpstate
& TMPFS_VNODE_ALLOCATING
);
470 node
->tn_vpstate
&= ~TMPFS_VNODE_ALLOCATING
;
473 if (node
->tn_vpstate
& TMPFS_VNODE_WANT
) {
474 node
->tn_vpstate
&= ~TMPFS_VNODE_WANT
;
475 TMPFS_NODE_UNLOCK(node
);
476 wakeup((caddr_t
) &node
->tn_vpstate
);
478 TMPFS_NODE_UNLOCK(node
);
483 KKASSERT(IFF(error
== 0, *vpp
!= NULL
&& vn_islocked(*vpp
)));
485 TMPFS_NODE_LOCK(node
);
486 KKASSERT(*vpp
== node
->tn_vnode
);
487 TMPFS_NODE_UNLOCK(node
);
493 /* --------------------------------------------------------------------- */
496 * Destroys the association between the vnode vp and the node it
500 tmpfs_free_vp(struct vnode
*vp
)
502 struct tmpfs_node
*node
;
504 node
= VP_TO_TMPFS_NODE(vp
);
506 TMPFS_NODE_LOCK(node
);
507 KKASSERT(lockcount(TMPFS_NODE_MTX(node
)) > 0);
508 node
->tn_vnode
= NULL
;
509 TMPFS_NODE_UNLOCK(node
);
513 /* --------------------------------------------------------------------- */
516 * Allocates a new file of type 'type' and adds it to the parent directory
517 * 'dvp'; this addition is done using the component name given in 'cnp'.
518 * The ownership of the new file is automatically assigned based on the
519 * credentials of the caller (through 'cnp'), the group is set based on
520 * the parent directory and the mode is determined from the 'vap' argument.
521 * If successful, *vpp holds a vnode to the newly created file and zero
522 * is returned. Otherwise *vpp is NULL and the function returns an
523 * appropriate error code.
526 tmpfs_alloc_file(struct vnode
*dvp
, struct vnode
**vpp
, struct vattr
*vap
,
527 struct namecache
*ncp
, struct ucred
*cred
, char *target
)
530 struct tmpfs_dirent
*de
;
531 struct tmpfs_mount
*tmp
;
532 struct tmpfs_node
*dnode
;
533 struct tmpfs_node
*node
;
534 struct tmpfs_node
*parent
;
536 tmp
= VFS_TO_TMPFS(dvp
->v_mount
);
537 dnode
= VP_TO_TMPFS_DIR(dvp
);
540 /* If the entry we are creating is a directory, we cannot overflow
541 * the number of links of its parent, because it will get a new
543 if (vap
->va_type
== VDIR
) {
544 /* Ensure that we do not overflow the maximum number of links
545 * imposed by the system. */
546 KKASSERT(dnode
->tn_links
<= LINK_MAX
);
547 if (dnode
->tn_links
== LINK_MAX
) {
552 KKASSERT(parent
!= NULL
);
556 /* Allocate a node that represents the new file. */
557 error
= tmpfs_alloc_node(tmp
, vap
->va_type
, cred
->cr_uid
,
558 dnode
->tn_gid
, vap
->va_mode
, parent
, target
, vap
->va_rmajor
, vap
->va_rminor
, &node
);
561 TMPFS_NODE_LOCK(node
);
563 /* Allocate a directory entry that points to the new file. */
564 error
= tmpfs_alloc_dirent(tmp
, node
, ncp
->nc_name
, ncp
->nc_nlen
, &de
);
566 tmpfs_free_node(tmp
, node
);
571 /* Allocate a vnode for the new file. */
572 error
= tmpfs_alloc_vp(dvp
->v_mount
, node
, LK_EXCLUSIVE
, vpp
);
574 tmpfs_free_dirent(tmp
, de
);
575 tmpfs_free_node(tmp
, node
);
580 /* Now that all required items are allocated, we can proceed to
581 * insert the new node into the directory, an operation that
583 tmpfs_dir_attach(dvp
, de
);
584 TMPFS_NODE_UNLOCK(node
);
589 /* --------------------------------------------------------------------- */
592 * Attaches the directory entry de to the directory represented by vp.
593 * Note that this does not change the link count of the node pointed by
594 * the directory entry, as this is done by tmpfs_alloc_dirent.
597 tmpfs_dir_attach(struct vnode
*vp
, struct tmpfs_dirent
*de
)
599 struct tmpfs_node
*dnode
;
601 dnode
= VP_TO_TMPFS_DIR(vp
);
603 TAILQ_INSERT_TAIL(&dnode
->tn_dir
.tn_dirhead
, de
, td_entries
);
605 TMPFS_NODE_LOCK(dnode
);
606 TMPFS_ASSERT_ELOCKED(dnode
);
607 dnode
->tn_size
+= sizeof(struct tmpfs_dirent
);
608 dnode
->tn_status
|= TMPFS_NODE_ACCESSED
| TMPFS_NODE_CHANGED
| \
610 TMPFS_NODE_UNLOCK(dnode
);
613 /* --------------------------------------------------------------------- */
616 * Detaches the directory entry de from the directory represented by vp.
617 * Note that this does not change the link count of the node pointed by
618 * the directory entry, as this is done by tmpfs_free_dirent.
621 tmpfs_dir_detach(struct vnode
*vp
, struct tmpfs_dirent
*de
)
623 struct tmpfs_node
*dnode
;
625 dnode
= VP_TO_TMPFS_DIR(vp
);
628 if (dnode
->tn_dir
.tn_readdir_lastp
== de
) {
629 dnode
->tn_dir
.tn_readdir_lastn
= 0;
630 dnode
->tn_dir
.tn_readdir_lastp
= NULL
;
632 TAILQ_REMOVE(&dnode
->tn_dir
.tn_dirhead
, de
, td_entries
);
634 TMPFS_NODE_LOCK(dnode
);
635 TMPFS_ASSERT_ELOCKED(dnode
);
636 dnode
->tn_size
-= sizeof(struct tmpfs_dirent
);
637 dnode
->tn_status
|= TMPFS_NODE_ACCESSED
| TMPFS_NODE_CHANGED
| \
639 TMPFS_NODE_UNLOCK(dnode
);
642 /* --------------------------------------------------------------------- */
645 * Looks for a directory entry in the directory represented by node.
646 * 'ncp' describes the name of the entry to look for. Note that the .
647 * and .. components are not allowed as they do not physically exist
648 * within directories.
650 * Returns a pointer to the entry when found, otherwise NULL.
652 struct tmpfs_dirent
*
653 tmpfs_dir_lookup(struct tmpfs_node
*node
, struct tmpfs_node
*f
,
654 struct namecache
*ncp
)
656 struct tmpfs_dirent
*de
;
657 int len
= ncp
->nc_nlen
;
659 TMPFS_VALIDATE_DIR(node
);
661 TAILQ_FOREACH(de
, &node
->tn_dir
.tn_dirhead
, td_entries
) {
662 if (f
!= NULL
&& de
->td_node
!= f
)
664 if (len
== de
->td_namelen
) {
665 if (!memcmp(ncp
->nc_name
, de
->td_name
, len
))
670 TMPFS_NODE_LOCK(node
);
671 node
->tn_status
|= TMPFS_NODE_ACCESSED
;
672 TMPFS_NODE_UNLOCK(node
);
677 /* --------------------------------------------------------------------- */
680 * Helper function for tmpfs_readdir. Creates a '.' entry for the given
681 * directory and returns it in the uio space. The function returns 0
682 * on success, -1 if there was not enough space in the uio structure to
683 * hold the directory entry or an appropriate error code if another
687 tmpfs_dir_getdotdent(struct tmpfs_node
*node
, struct uio
*uio
)
693 TMPFS_VALIDATE_DIR(node
);
694 KKASSERT(uio
->uio_offset
== TMPFS_DIRCOOKIE_DOT
);
696 dent
.d_ino
= node
->tn_id
;
697 dent
.d_type
= DT_DIR
;
699 dent
.d_name
[0] = '.';
700 dent
.d_name
[1] = '\0';
701 dirsize
= _DIRENT_DIRSIZ(&dent
);
703 if (dirsize
> uio
->uio_resid
)
706 error
= uiomove((caddr_t
)&dent
, dirsize
, uio
);
708 uio
->uio_offset
= TMPFS_DIRCOOKIE_DOTDOT
;
711 node
->tn_status
|= TMPFS_NODE_ACCESSED
;
716 /* --------------------------------------------------------------------- */
719 * Helper function for tmpfs_readdir. Creates a '..' entry for the given
720 * directory and returns it in the uio space. The function returns 0
721 * on success, -1 if there was not enough space in the uio structure to
722 * hold the directory entry or an appropriate error code if another
726 tmpfs_dir_getdotdotdent(struct tmpfs_node
*node
, struct uio
*uio
)
732 TMPFS_VALIDATE_DIR(node
);
733 KKASSERT(uio
->uio_offset
== TMPFS_DIRCOOKIE_DOTDOT
);
736 * Return ENOENT if the current node is already removed.
738 if (node
->tn_dir
.tn_parent
== NULL
) {
742 TMPFS_NODE_LOCK(node
->tn_dir
.tn_parent
);
743 dent
.d_ino
= node
->tn_dir
.tn_parent
->tn_id
;
744 TMPFS_NODE_UNLOCK(node
->tn_dir
.tn_parent
);
746 dent
.d_type
= DT_DIR
;
748 dent
.d_name
[0] = '.';
749 dent
.d_name
[1] = '.';
750 dent
.d_name
[2] = '\0';
751 dirsize
= _DIRENT_DIRSIZ(&dent
);
753 if (dirsize
> uio
->uio_resid
)
756 error
= uiomove((caddr_t
)&dent
, dirsize
, uio
);
758 struct tmpfs_dirent
*de
;
760 de
= TAILQ_FIRST(&node
->tn_dir
.tn_dirhead
);
762 uio
->uio_offset
= TMPFS_DIRCOOKIE_EOF
;
764 uio
->uio_offset
= tmpfs_dircookie(de
);
768 node
->tn_status
|= TMPFS_NODE_ACCESSED
;
773 /* --------------------------------------------------------------------- */
776 * Lookup a directory entry by its associated cookie.
778 struct tmpfs_dirent
*
779 tmpfs_dir_lookupbycookie(struct tmpfs_node
*node
, off_t cookie
)
781 struct tmpfs_dirent
*de
;
783 if (cookie
== node
->tn_dir
.tn_readdir_lastn
&&
784 node
->tn_dir
.tn_readdir_lastp
!= NULL
) {
785 return node
->tn_dir
.tn_readdir_lastp
;
788 TAILQ_FOREACH(de
, &node
->tn_dir
.tn_dirhead
, td_entries
) {
789 if (tmpfs_dircookie(de
) == cookie
) {
797 /* --------------------------------------------------------------------- */
800 * Helper function for tmpfs_readdir. Returns as much directory entries
801 * as can fit in the uio space. The read starts at uio->uio_offset.
802 * The function returns 0 on success, -1 if there was not enough space
803 * in the uio structure to hold the directory entry or an appropriate
804 * error code if another error happens.
807 tmpfs_dir_getdents(struct tmpfs_node
*node
, struct uio
*uio
, off_t
*cntp
)
811 struct tmpfs_dirent
*de
;
813 TMPFS_VALIDATE_DIR(node
);
815 /* Locate the first directory entry we have to return. We have cached
816 * the last readdir in the node, so use those values if appropriate.
817 * Otherwise do a linear scan to find the requested entry. */
818 startcookie
= uio
->uio_offset
;
819 KKASSERT(startcookie
!= TMPFS_DIRCOOKIE_DOT
);
820 KKASSERT(startcookie
!= TMPFS_DIRCOOKIE_DOTDOT
);
821 if (startcookie
== TMPFS_DIRCOOKIE_EOF
) {
824 de
= tmpfs_dir_lookupbycookie(node
, startcookie
);
830 /* Read as much entries as possible; i.e., until we reach the end of
831 * the directory or we exhaust uio space. */
836 /* Create a dirent structure representing the current
837 * tmpfs_node and fill it. */
838 d
.d_ino
= de
->td_node
->tn_id
;
839 switch (de
->td_node
->tn_type
) {
869 panic("tmpfs_dir_getdents: type %p %d",
870 de
->td_node
, (int)de
->td_node
->tn_type
);
872 d
.d_namlen
= de
->td_namelen
;
873 KKASSERT(de
->td_namelen
< sizeof(d
.d_name
));
874 bcopy(de
->td_name
, d
.d_name
, d
.d_namlen
);
875 d
.d_name
[d
.d_namlen
] = '\0';
876 reclen
= _DIRENT_RECLEN(d
.d_namlen
);
878 /* Stop reading if the directory entry we are treating is
879 * bigger than the amount of data that can be returned. */
880 if (reclen
> uio
->uio_resid
) {
885 /* Copy the new dirent structure into the output buffer and
886 * advance pointers. */
887 error
= uiomove((caddr_t
)&d
, reclen
, uio
);
890 de
= TAILQ_NEXT(de
, td_entries
);
891 } while (error
== 0 && uio
->uio_resid
> 0 && de
!= NULL
);
893 /* Update the offset and cache. */
895 uio
->uio_offset
= TMPFS_DIRCOOKIE_EOF
;
896 node
->tn_dir
.tn_readdir_lastn
= 0;
897 node
->tn_dir
.tn_readdir_lastp
= NULL
;
899 node
->tn_dir
.tn_readdir_lastn
= uio
->uio_offset
= tmpfs_dircookie(de
);
900 node
->tn_dir
.tn_readdir_lastp
= de
;
902 node
->tn_status
|= TMPFS_NODE_ACCESSED
;
907 /* --------------------------------------------------------------------- */
910 * Resizes the aobj associated to the regular file pointed to by vp to
911 * the size newsize. 'vp' must point to a vnode that represents a regular
912 * file. 'newsize' must be positive.
914 * pass trivial as 1 when buf content will be overwritten, otherwise set 0
917 * Returns zero on success or an appropriate error code on failure.
920 tmpfs_reg_resize(struct vnode
*vp
, off_t newsize
, int trivial
)
923 size_t newpages
, oldpages
;
924 struct tmpfs_mount
*tmp
;
925 struct tmpfs_node
*node
;
929 KKASSERT(vp
->v_type
== VREG
);
930 KKASSERT(newsize
>= 0);
933 node
= VP_TO_TMPFS_NODE(vp
);
934 tmp
= VFS_TO_TMPFS(vp
->v_mount
);
936 /* Convert the old and new sizes to the number of pages needed to
937 * store them. It may happen that we do not need to do anything
938 * because the last allocated page can accommodate the change on
940 oldsize
= node
->tn_size
;
941 oldpages
= round_page(oldsize
) / PAGE_SIZE
;
942 KKASSERT(oldpages
== node
->tn_reg
.tn_aobj_pages
);
943 newpages
= round_page(newsize
) / PAGE_SIZE
;
945 if (newpages
> oldpages
&&
946 newpages
- oldpages
> TMPFS_PAGES_AVAIL(tmp
)) {
952 tmp
->tm_pages_used
+= (newpages
- oldpages
);
955 TMPFS_NODE_LOCK(node
);
956 node
->tn_reg
.tn_aobj_pages
= newpages
;
957 node
->tn_size
= newsize
;
958 TMPFS_NODE_UNLOCK(node
);
961 * When adjusting the vnode filesize and its VM object we must
962 * also adjust our backing VM object (aobj). The blocksize
963 * used must match the block sized we use for the buffer cache.
965 if (newsize
< oldsize
) {
969 error
= nvtruncbuf(vp
, newsize
, BSIZE
, -1);
970 aobj
= node
->tn_reg
.tn_aobj
;
973 if (osize
> vp
->v_object
->size
) {
975 vm_object_page_remove(aobj
, vp
->v_object
->size
,
982 error
= nvextendbuf(vp
, oldsize
, newsize
, BSIZE
, BSIZE
,
984 aobj
= node
->tn_reg
.tn_aobj
;
986 aobj
->size
= vp
->v_object
->size
;
993 /* --------------------------------------------------------------------- */
996 * Change flags of the given vnode.
997 * Caller should execute tmpfs_update on vp after a successful execution.
998 * The vnode must be locked on entry and remain locked on exit.
1001 tmpfs_chflags(struct vnode
*vp
, int flags
, struct ucred
*cred
)
1004 struct tmpfs_node
*node
;
1007 KKASSERT(vn_islocked(vp
));
1009 node
= VP_TO_TMPFS_NODE(vp
);
1011 /* Disallow this operation if the file system is mounted read-only. */
1012 if (vp
->v_mount
->mnt_flag
& MNT_RDONLY
)
1015 fmode
= FFLAGS(node
->tn_flags
);
1017 if (((fmode
& (FREAD
| FWRITE
)) == 0) || (fmode
& O_CREAT
))
1019 if (fmode
& (FWRITE
| O_TRUNC
)) {
1020 if (vp
->v_type
== VDIR
) {
1023 error
= vn_writechk(vp
, NULL
);
1032 error
= VOP_ACCESS(vp
, mode
, cred
);
1037 * Unprivileged processes are not permitted to unset system
1038 * flags, or modify flags if any system flags are set.
1040 TMPFS_NODE_LOCK(node
);
1041 if (!priv_check_cred(cred
, PRIV_VFS_SYSFLAGS
, 0)) {
1044 & (SF_NOUNLINK
| SF_IMMUTABLE
| SF_APPEND
)) {
1045 error
= securelevel_gt(cred
, 0);
1049 /* Snapshot flag cannot be set or cleared */
1050 if (((flags
& SF_SNAPSHOT
) != 0 &&
1051 (node
->tn_flags
& SF_SNAPSHOT
) == 0) ||
1052 ((flags
& SF_SNAPSHOT
) == 0 &&
1053 (node
->tn_flags
& SF_SNAPSHOT
) != 0))
1056 node
->tn_flags
= flags
;
1059 & (SF_NOUNLINK
| SF_IMMUTABLE
| SF_APPEND
) ||
1060 (flags
& UF_SETTABLE
) != flags
)
1062 node
->tn_flags
&= SF_SETTABLE
;
1063 node
->tn_flags
|= (flags
& UF_SETTABLE
);
1065 node
->tn_status
|= TMPFS_NODE_CHANGED
;
1066 TMPFS_NODE_UNLOCK(node
);
1068 KKASSERT(vn_islocked(vp
));
1073 /* --------------------------------------------------------------------- */
1076 * Change access mode on the given vnode.
1077 * Caller should execute tmpfs_update on vp after a successful execution.
1078 * The vnode must be locked on entry and remain locked on exit.
1081 tmpfs_chmod(struct vnode
*vp
, mode_t mode
, struct ucred
*cred
)
1084 struct tmpfs_node
*node
;
1087 KKASSERT(vn_islocked(vp
));
1089 node
= VP_TO_TMPFS_NODE(vp
);
1091 /* Disallow this operation if the file system is mounted read-only. */
1092 if (vp
->v_mount
->mnt_flag
& MNT_RDONLY
)
1095 /* Immutable or append-only files cannot be modified, either. */
1096 if (node
->tn_flags
& (IMMUTABLE
| APPEND
))
1099 fmode
= FFLAGS(node
->tn_flags
);
1101 if (((fmode
& (FREAD
| FWRITE
)) == 0) || (fmode
& O_CREAT
))
1103 if (fmode
& (FWRITE
| O_TRUNC
)) {
1104 if (vp
->v_type
== VDIR
) {
1107 error
= vn_writechk(vp
, NULL
);
1116 error
= VOP_ACCESS(vp
, accmode
, cred
);
1122 * Privileged processes may set the sticky bit on non-directories,
1123 * as well as set the setgid bit on a file with a group that the
1124 * process is not a member of.
1126 if (vp
->v_type
!= VDIR
&& (mode
& S_ISTXT
)) {
1127 if (priv_check_cred(cred
, PRIV_VFS_STICKYFILE
, 0))
1130 if (!groupmember(node
->tn_gid
, cred
) && (mode
& S_ISGID
)) {
1131 error
= priv_check_cred(cred
, PRIV_VFS_SETGID
, 0);
1137 TMPFS_NODE_LOCK(node
);
1138 node
->tn_mode
&= ~ALLPERMS
;
1139 node
->tn_mode
|= mode
& ALLPERMS
;
1141 node
->tn_status
|= TMPFS_NODE_CHANGED
;
1142 TMPFS_NODE_UNLOCK(node
);
1144 KKASSERT(vn_islocked(vp
));
1149 /* --------------------------------------------------------------------- */
1152 * Change ownership of the given vnode. At least one of uid or gid must
1153 * be different than VNOVAL. If one is set to that value, the attribute
1155 * Caller should execute tmpfs_update on vp after a successful execution.
1156 * The vnode must be locked on entry and remain locked on exit.
1159 tmpfs_chown(struct vnode
*vp
, uid_t uid
, gid_t gid
, struct ucred
*cred
)
1162 struct tmpfs_node
*node
;
1167 KKASSERT(vn_islocked(vp
));
1169 node
= VP_TO_TMPFS_NODE(vp
);
1171 /* Assign default values if they are unknown. */
1172 KKASSERT(uid
!= VNOVAL
|| gid
!= VNOVAL
);
1177 KKASSERT(uid
!= VNOVAL
&& gid
!= VNOVAL
);
1179 /* Disallow this operation if the file system is mounted read-only. */
1180 if (vp
->v_mount
->mnt_flag
& MNT_RDONLY
)
1183 /* Immutable or append-only files cannot be modified, either. */
1184 if (node
->tn_flags
& (IMMUTABLE
| APPEND
))
1187 fmode
= FFLAGS(node
->tn_flags
);
1189 if (((fmode
& (FREAD
| FWRITE
)) == 0) || (fmode
& O_CREAT
))
1191 if (fmode
& (FWRITE
| O_TRUNC
)) {
1192 if (vp
->v_type
== VDIR
) {
1195 error
= vn_writechk(vp
, NULL
);
1204 error
= VOP_ACCESS(vp
, mode
, cred
);
1210 * To change the owner of a file, or change the group of a file to a
1211 * group of which we are not a member, the caller must have
1214 if ((uid
!= node
->tn_uid
||
1215 (gid
!= node
->tn_gid
&& !groupmember(gid
, cred
))) &&
1216 (error
= priv_check_cred(cred
, PRIV_VFS_CHOWN
, 0)))
1219 ogid
= node
->tn_gid
;
1220 ouid
= node
->tn_uid
;
1222 TMPFS_NODE_LOCK(node
);
1226 node
->tn_status
|= TMPFS_NODE_CHANGED
;
1228 if ((node
->tn_mode
& (S_ISUID
| S_ISGID
)) && (ouid
!= uid
|| ogid
!= gid
)) {
1229 if (priv_check_cred(cred
, PRIV_VFS_RETAINSUGID
, 0))
1230 node
->tn_mode
&= ~(S_ISUID
| S_ISGID
);
1232 TMPFS_NODE_UNLOCK(node
);
1234 KKASSERT(vn_islocked(vp
));
1239 /* --------------------------------------------------------------------- */
1242 * Change size of the given vnode.
1243 * Caller should execute tmpfs_update on vp after a successful execution.
1244 * The vnode must be locked on entry and remain locked on exit.
1247 tmpfs_chsize(struct vnode
*vp
, u_quad_t size
, struct ucred
*cred
)
1250 struct tmpfs_node
*node
;
1252 KKASSERT(vn_islocked(vp
));
1254 node
= VP_TO_TMPFS_NODE(vp
);
1256 /* Decide whether this is a valid operation based on the file type. */
1258 switch (vp
->v_type
) {
1263 if (vp
->v_mount
->mnt_flag
& MNT_RDONLY
)
1272 /* Allow modifications of special files even if in the file
1273 * system is mounted read-only (we are not modifying the
1274 * files themselves, but the objects they represent). */
1278 /* Anything else is unsupported. */
1282 /* Immutable or append-only files cannot be modified, either. */
1283 if (node
->tn_flags
& (IMMUTABLE
| APPEND
))
1286 error
= tmpfs_truncate(vp
, size
);
1287 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
1288 * for us, as will update tn_status; no need to do that here. */
1290 KKASSERT(vn_islocked(vp
));
1295 /* --------------------------------------------------------------------- */
1298 * Change access and modification times of the given vnode.
1299 * Caller should execute tmpfs_update on vp after a successful execution.
1300 * The vnode must be locked on entry and remain locked on exit.
1303 tmpfs_chtimes(struct vnode
*vp
, struct timespec
*atime
, struct timespec
*mtime
,
1304 int vaflags
, struct ucred
*cred
)
1307 struct tmpfs_node
*node
;
1310 KKASSERT(vn_islocked(vp
));
1312 node
= VP_TO_TMPFS_NODE(vp
);
1314 /* Disallow this operation if the file system is mounted read-only. */
1315 if (vp
->v_mount
->mnt_flag
& MNT_RDONLY
)
1318 /* Immutable or append-only files cannot be modified, either. */
1319 if (node
->tn_flags
& (IMMUTABLE
| APPEND
))
1322 /* Determine if the user have proper privilege to update time. */
1323 fmode
= FFLAGS(node
->tn_flags
);
1325 if (((fmode
& (FREAD
| FWRITE
)) == 0) || (fmode
& O_CREAT
))
1327 if (fmode
& (FWRITE
| O_TRUNC
)) {
1328 if (vp
->v_type
== VDIR
) {
1331 error
= vn_writechk(vp
, NULL
);
1341 if (vaflags
& VA_UTIMES_NULL
) {
1342 error
= VOP_ACCESS(vp
, mode
, cred
);
1344 error
= VOP_ACCESS(vp
, VWRITE
, cred
);
1346 error
= VOP_ACCESS(vp
, mode
, cred
);
1351 TMPFS_NODE_LOCK(node
);
1352 if (atime
->tv_sec
!= VNOVAL
&& atime
->tv_nsec
!= VNOVAL
)
1353 node
->tn_status
|= TMPFS_NODE_ACCESSED
;
1355 if (mtime
->tv_sec
!= VNOVAL
&& mtime
->tv_nsec
!= VNOVAL
)
1356 node
->tn_status
|= TMPFS_NODE_MODIFIED
;
1358 TMPFS_NODE_UNLOCK(node
);
1360 tmpfs_itimes(vp
, atime
, mtime
);
1362 KKASSERT(vn_islocked(vp
));
1367 /* --------------------------------------------------------------------- */
1368 /* Sync timestamps */
1370 tmpfs_itimes(struct vnode
*vp
, const struct timespec
*acc
,
1371 const struct timespec
*mod
)
1373 struct tmpfs_node
*node
;
1374 struct timespec now
;
1376 node
= VP_TO_TMPFS_NODE(vp
);
1378 if ((node
->tn_status
& (TMPFS_NODE_ACCESSED
| TMPFS_NODE_MODIFIED
|
1379 TMPFS_NODE_CHANGED
)) == 0)
1382 vfs_timestamp(&now
);
1384 TMPFS_NODE_LOCK(node
);
1385 if (node
->tn_status
& TMPFS_NODE_ACCESSED
) {
1388 node
->tn_atime
= acc
->tv_sec
;
1389 node
->tn_atimensec
= acc
->tv_nsec
;
1391 if (node
->tn_status
& TMPFS_NODE_MODIFIED
) {
1394 node
->tn_mtime
= mod
->tv_sec
;
1395 node
->tn_mtimensec
= mod
->tv_nsec
;
1397 if (node
->tn_status
& TMPFS_NODE_CHANGED
) {
1398 node
->tn_ctime
= now
.tv_sec
;
1399 node
->tn_ctimensec
= now
.tv_nsec
;
1402 ~(TMPFS_NODE_ACCESSED
| TMPFS_NODE_MODIFIED
| TMPFS_NODE_CHANGED
);
1403 TMPFS_NODE_UNLOCK(node
);
1406 /* --------------------------------------------------------------------- */
1409 tmpfs_update(struct vnode
*vp
)
1412 tmpfs_itimes(vp
, NULL
, NULL
);
1415 /* --------------------------------------------------------------------- */
1418 tmpfs_truncate(struct vnode
*vp
, off_t length
)
1421 struct tmpfs_node
*node
;
1423 node
= VP_TO_TMPFS_NODE(vp
);
1430 if (node
->tn_size
== length
) {
1435 if (length
> VFS_TO_TMPFS(vp
->v_mount
)->tm_maxfilesize
)
1439 error
= tmpfs_reg_resize(vp
, length
, 1);
1442 TMPFS_NODE_LOCK(node
);
1443 node
->tn_status
|= TMPFS_NODE_CHANGED
| TMPFS_NODE_MODIFIED
;
1444 TMPFS_NODE_UNLOCK(node
);
1453 /* --------------------------------------------------------------------- */
1456 tmpfs_fetch_ino(void)
1460 spin_lock_wr(&ino_lock
);
1462 spin_unlock_wr(&ino_lock
);