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.
37 #include <sys/kernel.h>
38 #include <sys/param.h>
39 #include <sys/namei.h>
43 #include <sys/systm.h>
44 #include <sys/vnode.h>
45 #include <sys/vmmeter.h>
48 #include <vm/vm_object.h>
49 #include <vm/vm_page.h>
50 #include <vm/vm_pager.h>
51 #include <vm/vm_extern.h>
53 #include <vfs/tmpfs/tmpfs.h>
54 #include <vfs/tmpfs/tmpfs_vnops.h>
56 static ino_t tmpfs_fetch_ino(struct tmpfs_mount *);
58 static int tmpfs_dirtree_compare(struct tmpfs_dirent *a,
59 struct tmpfs_dirent *b);
60 RB_GENERATE(tmpfs_dirtree, tmpfs_dirent, rb_node, tmpfs_dirtree_compare);
62 static int tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a,
63 struct tmpfs_dirent *b);
64 RB_GENERATE(tmpfs_dirtree_cookie, tmpfs_dirent,
65 rb_cookienode, tmpfs_dirtree_compare_cookie);
68 /* --------------------------------------------------------------------- */
71 * Allocates a new node of type 'type' inside the 'tmp' mount point, with
72 * its owner set to 'uid', its group to 'gid' and its mode set to 'mode',
73 * using the credentials of the process 'p'.
75 * If the node type is set to 'VDIR', then the parent parameter must point
76 * to the parent directory of the node being created. It may only be NULL
77 * while allocating the root node.
79 * If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter
80 * specifies the device the node represents.
82 * If the node type is set to 'VLNK', then the parameter target specifies
83 * the file name of the target file for the symbolic link that is being
86 * Note that new nodes are retrieved from the available list if it has
87 * items or, if it is empty, from the node pool as long as there is enough
88 * space to create them.
90 * Returns zero on success or an appropriate error code on failure.
93 tmpfs_alloc_node(struct tmpfs_mount *tmp, enum vtype type,
94 uid_t uid, gid_t gid, mode_t mode,
95 char *target, int rmajor, int rminor,
96 struct tmpfs_node **node)
98 struct tmpfs_node *nnode;
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 = objcache_get(tmp->tm_node_pool, M_WAITOK | M_NULLOK);
112 /* Generic initialization. */
113 nnode->tn_type = type;
115 nnode->tn_ctime = nnode->tn_mtime = nnode->tn_atime
117 nnode->tn_ctimensec = nnode->tn_mtimensec = nnode->tn_atimensec
121 nnode->tn_mode = mode;
122 nnode->tn_id = tmpfs_fetch_ino(tmp);
123 nnode->tn_advlock.init_done = 0;
124 KKASSERT(nnode->tn_links == 0);
126 /* Type-specific initialization. */
127 switch (nnode->tn_type) {
130 rdev = makeudev(rmajor, rminor);
131 if (rdev == NOUDEV) {
132 objcache_put(tmp->tm_node_pool, nnode);
135 nnode->tn_rdev = rdev;
139 RB_INIT(&nnode->tn_dir.tn_dirtree);
140 RB_INIT(&nnode->tn_dir.tn_cookietree);
150 nnode->tn_size = strlen(target);
151 nnode->tn_link = kmalloc(nnode->tn_size + 1, tmp->tm_name_zone,
152 M_WAITOK | M_NULLOK);
153 if (nnode->tn_link == NULL) {
154 objcache_put(tmp->tm_node_pool, nnode);
157 bcopy(target, nnode->tn_link, nnode->tn_size);
158 nnode->tn_link[nnode->tn_size] = '\0';
162 nnode->tn_reg.tn_aobj = swap_pager_alloc(NULL, 0,
164 nnode->tn_reg.tn_aobj_pages = 0;
166 vm_object_set_flag(nnode->tn_reg.tn_aobj, OBJ_NOPAGEIN);
170 panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type);
173 TMPFS_NODE_LOCK(nnode);
175 LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries);
176 tmp->tm_nodes_inuse++;
178 TMPFS_NODE_UNLOCK(nnode);
184 /* --------------------------------------------------------------------- */
187 * Destroys the node pointed to by node from the file system 'tmp'.
188 * If the node does not belong to the given mount point, the results are
191 * If the node references a directory; no entries are allowed because
192 * their removal could need a recursive algorithm, something forbidden in
193 * kernel space. Furthermore, there is not need to provide such
194 * functionality (recursive removal) because the only primitives offered
195 * to the user are the removal of empty directories and the deletion of
198 * Note that nodes are not really deleted; in fact, when a node has been
199 * allocated, it cannot be deleted during the whole life of the file
200 * system. Instead, they are moved to the available list and remain there
203 * A caller must have TMPFS_NODE_LOCK(node) and this function unlocks it.
206 tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node)
208 vm_pindex_t pages = 0;
211 TMPFS_ASSERT_ELOCKED(node);
212 KKASSERT(node->tn_vnode == NULL);
213 KKASSERT((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0);
217 LIST_REMOVE(node, tn_entries);
218 tmp->tm_nodes_inuse--;
220 TMPFS_NODE_UNLOCK(node); /* Caller has this lock */
222 switch (node->tn_type) {
224 /* Do not do anything. VNON is provided to let the
225 * allocation routine clean itself easily by avoiding
226 * duplicating code in it. */
235 * The parent link can be NULL if this is the root
236 * node or if it is a directory node that was rmdir'd.
238 * XXX what if node is a directory which still contains
239 * directory entries (e.g. due to a forced umount) ?
242 KKASSERT(node->tn_dir.tn_parent == NULL);
245 * If the root node is being destroyed don't leave a
246 * dangling pointer in tmpfs_mount.
248 if (node == tmp->tm_root)
257 kfree(node->tn_link, tmp->tm_name_zone);
258 node->tn_link = NULL;
263 if (node->tn_reg.tn_aobj != NULL)
264 vm_object_deallocate(node->tn_reg.tn_aobj);
265 node->tn_reg.tn_aobj = NULL;
266 pages = node->tn_reg.tn_aobj_pages;
270 panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type);
274 * Clean up fields for the next allocation. The objcache only ctors
277 tmpfs_node_ctor(node, NULL, 0);
278 objcache_put(tmp->tm_node_pool, node);
279 /* node is now invalid */
282 atomic_add_long(&tmp->tm_pages_used, -(long)pages);
285 /* --------------------------------------------------------------------- */
288 * Allocates a new directory entry for the node node with a name of name.
289 * The new directory entry is returned in *de.
291 * The link count of node is increased by one to reflect the new object
294 * Returns zero on success or an appropriate error code on failure.
297 tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
298 const char *name, uint16_t len, struct tmpfs_dirent **de)
300 struct tmpfs_dirent *nde;
302 nde = objcache_get(tmp->tm_dirent_pool, M_WAITOK);
303 nde->td_name = kmalloc(len + 1, tmp->tm_name_zone, M_WAITOK | M_NULLOK);
304 if (nde->td_name == NULL) {
305 objcache_put(tmp->tm_dirent_pool, nde);
309 nde->td_namelen = len;
310 bcopy(name, nde->td_name, len);
311 nde->td_name[len] = '\0';
315 TMPFS_NODE_LOCK(node);
317 TMPFS_NODE_UNLOCK(node);
324 /* --------------------------------------------------------------------- */
327 * Frees a directory entry. It is the caller's responsibility to destroy
328 * the node referenced by it if needed.
330 * The link count of node is decreased by one to reflect the removal of an
331 * object that referenced it. This only happens if 'node_exists' is true;
332 * otherwise the function will not access the node referred to by the
333 * directory entry, as it may already have been released from the outside.
336 tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de)
338 struct tmpfs_node *node;
342 TMPFS_NODE_LOCK(node);
343 TMPFS_ASSERT_ELOCKED(node);
344 KKASSERT(node->tn_links > 0);
346 TMPFS_NODE_UNLOCK(node);
348 kfree(de->td_name, tmp->tm_name_zone);
352 objcache_put(tmp->tm_dirent_pool, de);
355 /* --------------------------------------------------------------------- */
358 * Allocates a new vnode for the node node or returns a new reference to
359 * an existing one if the node had already a vnode referencing it. The
360 * resulting locked vnode is returned in *vpp.
362 * Returns zero on success or an appropriate error code on failure.
365 tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag,
373 * Interlocked extraction from node. This can race many things.
374 * We have to get a soft reference on the vnode while we hold
375 * the node locked, then acquire it properly and check for races.
377 TMPFS_NODE_LOCK(node);
378 if ((vp = node->tn_vnode) != NULL) {
379 KKASSERT((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0);
381 TMPFS_NODE_UNLOCK(node);
383 if (vget(vp, lkflag | LK_EXCLUSIVE) != 0) {
387 if (node->tn_vnode != vp) {
398 * This should never happen.
400 if (node->tn_vpstate & TMPFS_VNODE_DOOMED) {
401 TMPFS_NODE_UNLOCK(node);
407 * Interlock against other calls to tmpfs_alloc_vp() trying to
408 * allocate and assign a vp to node.
410 if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) {
411 node->tn_vpstate |= TMPFS_VNODE_WANT;
412 error = tsleep(&node->tn_vpstate, PINTERLOCKED | PCATCH,
413 "tmpfs_alloc_vp", 0);
414 TMPFS_NODE_UNLOCK(node);
419 node->tn_vpstate |= TMPFS_VNODE_ALLOCATING;
420 TMPFS_NODE_UNLOCK(node);
423 * Allocate a new vnode (may block). The ALLOCATING flag should
424 * prevent a race against someone else assigning node->tn_vnode.
426 error = getnewvnode(VT_TMPFS, mp, &vp, VLKTIMEOUT, LK_CANRECURSE);
430 KKASSERT(node->tn_vnode == NULL);
431 KKASSERT(vp != NULL);
433 vp->v_type = node->tn_type;
435 /* Type-specific initialization. */
436 switch (node->tn_type) {
445 * VMIO is mandatory. Tmpfs also supports KVABIO
446 * for its tmpfs_strategy().
448 vsetflags(vp, VKVABIO);
449 vinitvmio(vp, node->tn_size, TMPFS_BLKSIZE, -1);
454 vp->v_ops = &mp->mnt_vn_fifo_ops;
460 panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type);
465 TMPFS_NODE_LOCK(node);
467 KKASSERT(node->tn_vpstate & TMPFS_VNODE_ALLOCATING);
468 node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING;
471 if (node->tn_vpstate & TMPFS_VNODE_WANT) {
472 node->tn_vpstate &= ~TMPFS_VNODE_WANT;
473 TMPFS_NODE_UNLOCK(node);
474 wakeup(&node->tn_vpstate);
476 TMPFS_NODE_UNLOCK(node);
482 KKASSERT(IFF(error == 0, *vpp != NULL && vn_islocked(*vpp)));
484 TMPFS_NODE_LOCK(node);
485 KKASSERT(*vpp == node->tn_vnode);
486 TMPFS_NODE_UNLOCK(node);
492 /* --------------------------------------------------------------------- */
495 * Destroys the association between the vnode vp and the node it
499 tmpfs_free_vp(struct vnode *vp)
501 struct tmpfs_node *node;
503 node = VP_TO_TMPFS_NODE(vp);
505 TMPFS_NODE_LOCK(node);
506 KKASSERT(lockinuse(TMPFS_NODE_MTX(node)));
507 node->tn_vnode = NULL;
509 TMPFS_NODE_UNLOCK(node);
512 /* --------------------------------------------------------------------- */
515 * Allocates a new file of type 'type' and adds it to the parent directory
516 * 'dvp'; this addition is done using the component name given in 'cnp'.
517 * The ownership of the new file is automatically assigned based on the
518 * credentials of the caller (through 'cnp'), the group is set based on
519 * the parent directory and the mode is determined from the 'vap' argument.
520 * If successful, *vpp holds a vnode to the newly created file and zero
521 * is returned. Otherwise *vpp is NULL and the function returns an
522 * appropriate error code.
525 tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap,
526 struct namecache *ncp, struct ucred *cred, char *target)
529 struct tmpfs_dirent *de;
530 struct tmpfs_mount *tmp;
531 struct tmpfs_node *dnode;
532 struct tmpfs_node *node;
534 tmp = VFS_TO_TMPFS(dvp->v_mount);
535 dnode = VP_TO_TMPFS_DIR(dvp);
539 * If the directory was removed but a process was CD'd into it,
540 * we do not allow any more file/dir creation within it. Otherwise
541 * we will lose track of it.
543 KKASSERT(dnode->tn_type == VDIR);
544 if (dnode != tmp->tm_root && dnode->tn_dir.tn_parent == NULL)
548 * Make sure the link count does not overflow.
550 if (vap->va_type == VDIR && dnode->tn_links >= LINK_MAX)
553 /* Allocate a node that represents the new file. */
554 error = tmpfs_alloc_node(tmp, vap->va_type, cred->cr_uid,
555 dnode->tn_gid, vap->va_mode, target,
556 vap->va_rmajor, vap->va_rminor, &node);
559 TMPFS_NODE_LOCK(node);
561 /* Allocate a directory entry that points to the new file. */
562 error = tmpfs_alloc_dirent(tmp, node, ncp->nc_name, ncp->nc_nlen, &de);
564 tmpfs_free_node(tmp, node);
569 /* Allocate a vnode for the new file. */
570 error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp);
572 tmpfs_free_dirent(tmp, de);
573 tmpfs_free_node(tmp, node);
579 * Now that all required items are allocated, we can proceed to
580 * insert the new node into the directory, an operation that
583 tmpfs_dir_attach(dnode, de);
584 TMPFS_NODE_UNLOCK(node);
589 /* --------------------------------------------------------------------- */
592 * Attaches the directory entry de to the directory represented by dnode.
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 tmpfs_node *dnode, struct tmpfs_dirent *de)
599 struct tmpfs_node *node = de->td_node;
601 TMPFS_NODE_LOCK(dnode);
602 if (node && node->tn_type == VDIR) {
603 TMPFS_NODE_LOCK(node);
605 node->tn_status |= TMPFS_NODE_CHANGED;
606 node->tn_dir.tn_parent = dnode;
608 TMPFS_NODE_UNLOCK(node);
610 RB_INSERT(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de);
611 RB_INSERT(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de);
612 dnode->tn_size += sizeof(struct tmpfs_dirent);
613 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
615 TMPFS_NODE_UNLOCK(dnode);
618 /* --------------------------------------------------------------------- */
621 * Detaches the directory entry de from the directory represented by dnode.
622 * Note that this does not change the link count of the node pointed by
623 * the directory entry, as this is done by tmpfs_free_dirent.
626 tmpfs_dir_detach(struct tmpfs_node *dnode, struct tmpfs_dirent *de)
628 struct tmpfs_node *node = de->td_node;
630 TMPFS_NODE_LOCK(dnode);
631 RB_REMOVE(tmpfs_dirtree, &dnode->tn_dir.tn_dirtree, de);
632 RB_REMOVE(tmpfs_dirtree_cookie, &dnode->tn_dir.tn_cookietree, de);
633 dnode->tn_size -= sizeof(struct tmpfs_dirent);
634 dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED |
636 TMPFS_NODE_UNLOCK(dnode);
639 * Clean out the tn_parent pointer immediately when removing a
642 * Removal of the parent linkage also cleans out the extra tn_links
643 * count we had on both node and dnode.
645 * node can be NULL (typ during a forced umount), in which case
646 * the mount code is dealing with the linkages from a linked list
649 if (node && node->tn_type == VDIR && node->tn_dir.tn_parent) {
650 TMPFS_NODE_LOCK(dnode);
651 TMPFS_NODE_LOCK(node);
652 KKASSERT(node->tn_dir.tn_parent == dnode);
655 node->tn_dir.tn_parent = NULL;
656 TMPFS_NODE_UNLOCK(node);
657 TMPFS_NODE_UNLOCK(dnode);
661 /* --------------------------------------------------------------------- */
664 * Looks for a directory entry in the directory represented by node.
665 * 'ncp' describes the name of the entry to look for. Note that the .
666 * and .. components are not allowed as they do not physically exist
667 * within directories.
669 * Returns a pointer to the entry when found, otherwise NULL.
671 * Caller must hold the node locked (shared ok)
673 struct tmpfs_dirent *
674 tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f,
675 struct namecache *ncp)
677 struct tmpfs_dirent *de;
678 int len = ncp->nc_nlen;
679 struct tmpfs_dirent wanted;
681 wanted.td_namelen = len;
682 wanted.td_name = ncp->nc_name;
684 TMPFS_VALIDATE_DIR(node);
686 de = RB_FIND(tmpfs_dirtree, &node->tn_dir.tn_dirtree, &wanted);
688 KKASSERT(f == NULL || f == de->td_node);
693 /* --------------------------------------------------------------------- */
696 * Helper function for tmpfs_readdir. Creates a '.' entry for the given
697 * directory and returns it in the uio space. The function returns 0
698 * on success, -1 if there was not enough space in the uio structure to
699 * hold the directory entry or an appropriate error code if another
703 tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio)
707 TMPFS_VALIDATE_DIR(node);
708 KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOT);
710 if (vop_write_dirent(&error, uio, node->tn_id, DT_DIR, 1, "."))
713 uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT;
717 /* --------------------------------------------------------------------- */
720 * Helper function for tmpfs_readdir. Creates a '..' entry for the given
721 * directory and returns it in the uio space. The function returns 0
722 * on success, -1 if there was not enough space in the uio structure to
723 * hold the directory entry or an appropriate error code if another
727 tmpfs_dir_getdotdotdent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
733 TMPFS_VALIDATE_DIR(node);
734 KKASSERT(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
736 if (node->tn_dir.tn_parent) {
737 TMPFS_NODE_LOCK(node);
738 if (node->tn_dir.tn_parent)
739 d_ino = node->tn_dir.tn_parent->tn_id;
741 d_ino = tmp->tm_root->tn_id;
742 TMPFS_NODE_UNLOCK(node);
744 d_ino = tmp->tm_root->tn_id;
747 if (vop_write_dirent(&error, uio, d_ino, DT_DIR, 2, ".."))
750 struct tmpfs_dirent *de;
751 de = RB_MIN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree);
753 uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
755 uio->uio_offset = tmpfs_dircookie(de);
760 /* --------------------------------------------------------------------- */
763 * Lookup a directory entry by its associated cookie.
765 * Must be called with the directory node locked (shared ok)
767 struct lubycookie_info {
769 struct tmpfs_dirent *de;
773 lubycookie_cmp(struct tmpfs_dirent *de, void *arg)
775 struct lubycookie_info *info = arg;
776 off_t cookie = tmpfs_dircookie(de);
778 if (cookie < info->cookie)
780 if (cookie > info->cookie)
786 lubycookie_callback(struct tmpfs_dirent *de, void *arg)
788 struct lubycookie_info *info = arg;
790 if (tmpfs_dircookie(de) == info->cookie) {
797 struct tmpfs_dirent *
798 tmpfs_dir_lookupbycookie(struct tmpfs_node *node, off_t cookie)
800 struct lubycookie_info info;
802 info.cookie = cookie;
804 RB_SCAN(tmpfs_dirtree_cookie, &node->tn_dir.tn_cookietree,
805 lubycookie_cmp, lubycookie_callback, &info);
809 /* --------------------------------------------------------------------- */
812 * Helper function for tmpfs_readdir. Returns as much directory entries
813 * as can fit in the uio space. The read starts at uio->uio_offset.
814 * The function returns 0 on success, -1 if there was not enough space
815 * in the uio structure to hold the directory entry or an appropriate
816 * error code if another error happens.
818 * Caller must hold the node locked (shared ok)
821 tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, off_t *cntp)
825 struct tmpfs_dirent *de;
827 TMPFS_VALIDATE_DIR(node);
830 * Locate the first directory entry we have to return. We have cached
831 * the last readdir in the node, so use those values if appropriate.
832 * Otherwise do a linear scan to find the requested entry.
834 startcookie = uio->uio_offset;
835 KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOT);
836 KKASSERT(startcookie != TMPFS_DIRCOOKIE_DOTDOT);
838 if (startcookie == TMPFS_DIRCOOKIE_EOF)
841 de = tmpfs_dir_lookupbycookie(node, startcookie);
846 * Read as much entries as possible; i.e., until we reach the end of
847 * the directory or we exhaust uio space.
853 /* Create a dirent structure representing the current
854 * tmpfs_node and fill it. */
855 d_ino = de->td_node->tn_id;
856 switch (de->td_node->tn_type) {
886 panic("tmpfs_dir_getdents: type %p %d",
887 de->td_node, (int)de->td_node->tn_type);
889 KKASSERT(de->td_namelen < 256); /* 255 + 1 */
891 if (vop_write_dirent(&error, uio, d_ino, d_type,
892 de->td_namelen, de->td_name)) {
898 de = RB_NEXT(tmpfs_dirtree_cookie,
899 node->tn_dir.tn_cookietree, de);
900 } while (error == 0 && uio->uio_resid > 0 && de != NULL);
902 /* Update the offset and cache. */
904 uio->uio_offset = TMPFS_DIRCOOKIE_EOF;
906 uio->uio_offset = tmpfs_dircookie(de);
912 /* --------------------------------------------------------------------- */
915 * Resizes the aobj associated to the regular file pointed to by vp to
916 * the size newsize. 'vp' must point to a vnode that represents a regular
917 * file. 'newsize' must be positive.
919 * pass trivial as 1 when buf content will be overwritten, otherwise set 0
922 * Returns zero on success or an appropriate error code on failure.
924 * Caller must hold the node exclusively locked.
927 tmpfs_reg_resize(struct vnode *vp, off_t newsize, int trivial)
930 vm_pindex_t newpages, oldpages;
931 struct tmpfs_mount *tmp;
932 struct tmpfs_node *node;
936 KKASSERT(vp->v_type == VREG);
937 KKASSERT(newsize >= 0);
940 node = VP_TO_TMPFS_NODE(vp);
941 tmp = VFS_TO_TMPFS(vp->v_mount);
944 * Convert the old and new sizes to the number of pages needed to
945 * store them. It may happen that we do not need to do anything
946 * because the last allocated page can accommodate the change on
949 oldsize = node->tn_size;
950 oldpages = round_page64(oldsize) / PAGE_SIZE;
951 KKASSERT(oldpages == node->tn_reg.tn_aobj_pages);
952 newpages = round_page64(newsize) / PAGE_SIZE;
954 if (newpages > oldpages &&
955 tmp->tm_pages_used + newpages - oldpages > tmp->tm_pages_max) {
959 node->tn_reg.tn_aobj_pages = newpages;
960 node->tn_size = newsize;
962 if (newpages != oldpages)
963 atomic_add_long(&tmp->tm_pages_used, (newpages - oldpages));
966 * When adjusting the vnode filesize and its VM object we must
967 * also adjust our backing VM object (aobj). The blocksize
968 * used must match the block sized we use for the buffer cache.
970 * The backing VM object may contain VM pages as well as swap
971 * assignments if we previously renamed main object pages into
972 * it during deactivation.
974 if (newsize < oldsize) {
979 error = nvtruncbuf(vp, newsize, TMPFS_BLKSIZE, -1, 0);
980 aobj = node->tn_reg.tn_aobj;
983 nsize = vp->v_object->size;
986 swap_pager_freespace(aobj, nsize,
988 vm_object_page_remove(aobj, nsize, osize,
995 error = nvextendbuf(vp, oldsize, newsize,
996 TMPFS_BLKSIZE, TMPFS_BLKSIZE,
998 aobj = node->tn_reg.tn_aobj;
1000 aobj->size = vp->v_object->size;
1007 /* --------------------------------------------------------------------- */
1010 * Change flags of the given vnode.
1011 * Caller should execute tmpfs_update on vp after a successful execution.
1012 * The vnode must be locked on entry and remain locked on exit.
1015 tmpfs_chflags(struct vnode *vp, int vaflags, struct ucred *cred)
1018 struct tmpfs_node *node;
1021 KKASSERT(vn_islocked(vp));
1023 node = VP_TO_TMPFS_NODE(vp);
1024 flags = node->tn_flags;
1026 /* Disallow this operation if the file system is mounted read-only. */
1027 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1029 error = vop_helper_setattr_flags(&flags, vaflags, node->tn_uid, cred);
1031 /* Actually change the flags on the node itself */
1033 TMPFS_NODE_LOCK(node);
1034 node->tn_flags = flags;
1035 node->tn_status |= TMPFS_NODE_CHANGED;
1036 TMPFS_NODE_UNLOCK(node);
1039 KKASSERT(vn_islocked(vp));
1044 /* --------------------------------------------------------------------- */
1047 * Change access mode on the given vnode.
1048 * Caller should execute tmpfs_update on vp after a successful execution.
1049 * The vnode must be locked on entry and remain locked on exit.
1052 tmpfs_chmod(struct vnode *vp, mode_t vamode, struct ucred *cred)
1054 struct tmpfs_node *node;
1058 KKASSERT(vn_islocked(vp));
1060 node = VP_TO_TMPFS_NODE(vp);
1062 /* Disallow this operation if the file system is mounted read-only. */
1063 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1066 /* Immutable or append-only files cannot be modified, either. */
1067 if (node->tn_flags & (IMMUTABLE | APPEND))
1070 cur_mode = node->tn_mode;
1071 error = vop_helper_chmod(vp, vamode, cred, node->tn_uid, node->tn_gid,
1075 (node->tn_mode & ALLPERMS) != (cur_mode & ALLPERMS)) {
1076 TMPFS_NODE_LOCK(node);
1077 node->tn_mode &= ~ALLPERMS;
1078 node->tn_mode |= cur_mode & ALLPERMS;
1080 node->tn_status |= TMPFS_NODE_CHANGED;
1081 TMPFS_NODE_UNLOCK(node);
1084 KKASSERT(vn_islocked(vp));
1089 /* --------------------------------------------------------------------- */
1092 * Change ownership of the given vnode. At least one of uid or gid must
1093 * be different than VNOVAL. If one is set to that value, the attribute
1095 * Caller should execute tmpfs_update on vp after a successful execution.
1096 * The vnode must be locked on entry and remain locked on exit.
1099 tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred)
1104 struct tmpfs_node *node;
1107 KKASSERT(vn_islocked(vp));
1108 node = VP_TO_TMPFS_NODE(vp);
1110 /* Disallow this operation if the file system is mounted read-only. */
1111 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1114 /* Immutable or append-only files cannot be modified, either. */
1115 if (node->tn_flags & (IMMUTABLE | APPEND))
1118 cur_uid = node->tn_uid;
1119 cur_gid = node->tn_gid;
1120 cur_mode = node->tn_mode;
1121 error = vop_helper_chown(vp, uid, gid, cred,
1122 &cur_uid, &cur_gid, &cur_mode);
1125 TMPFS_NODE_LOCK(node);
1126 if (cur_uid != node->tn_uid ||
1127 cur_gid != node->tn_gid ||
1128 cur_mode != node->tn_mode) {
1129 node->tn_uid = cur_uid;
1130 node->tn_gid = cur_gid;
1131 node->tn_mode = cur_mode;
1132 node->tn_status |= TMPFS_NODE_CHANGED;
1134 TMPFS_NODE_UNLOCK(node);
1140 /* --------------------------------------------------------------------- */
1143 * Change size of the given vnode.
1144 * Caller should execute tmpfs_update on vp after a successful execution.
1145 * The vnode must be locked on entry and remain locked on exit.
1148 tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred)
1151 struct tmpfs_node *node;
1153 KKASSERT(vn_islocked(vp));
1155 node = VP_TO_TMPFS_NODE(vp);
1157 /* Decide whether this is a valid operation based on the file type. */
1159 switch (vp->v_type) {
1164 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1173 /* Allow modifications of special files even if in the file
1174 * system is mounted read-only (we are not modifying the
1175 * files themselves, but the objects they represent). */
1179 /* Anything else is unsupported. */
1183 /* Immutable or append-only files cannot be modified, either. */
1184 if (node->tn_flags & (IMMUTABLE | APPEND))
1187 error = tmpfs_truncate(vp, size);
1188 /* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
1189 * for us, as will update tn_status; no need to do that here. */
1191 KKASSERT(vn_islocked(vp));
1196 /* --------------------------------------------------------------------- */
1199 * Change access and modification times of the given vnode.
1200 * Caller should execute tmpfs_update on vp after a successful execution.
1201 * The vnode must be locked on entry and remain locked on exit.
1204 tmpfs_chtimes(struct vnode *vp, struct timespec *atime, struct timespec *mtime,
1205 int vaflags, struct ucred *cred)
1207 struct tmpfs_node *node;
1209 KKASSERT(vn_islocked(vp));
1211 node = VP_TO_TMPFS_NODE(vp);
1213 /* Disallow this operation if the file system is mounted read-only. */
1214 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1217 /* Immutable or append-only files cannot be modified, either. */
1218 if (node->tn_flags & (IMMUTABLE | APPEND))
1221 TMPFS_NODE_LOCK(node);
1222 if (atime->tv_sec != VNOVAL && atime->tv_nsec != VNOVAL)
1223 node->tn_status |= TMPFS_NODE_ACCESSED;
1225 if (mtime->tv_sec != VNOVAL && mtime->tv_nsec != VNOVAL) {
1226 node->tn_status |= TMPFS_NODE_MODIFIED;
1227 vclrflags(vp, VLASTWRITETS);
1230 TMPFS_NODE_UNLOCK(node);
1232 tmpfs_itimes(vp, atime, mtime);
1234 KKASSERT(vn_islocked(vp));
1239 /* --------------------------------------------------------------------- */
1240 /* Sync timestamps */
1242 tmpfs_itimes(struct vnode *vp, const struct timespec *acc,
1243 const struct timespec *mod)
1245 struct tmpfs_node *node;
1246 struct timespec now;
1248 node = VP_TO_TMPFS_NODE(vp);
1250 if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
1251 TMPFS_NODE_CHANGED)) == 0)
1254 vfs_timestamp(&now);
1256 TMPFS_NODE_LOCK(node);
1257 if (node->tn_status & TMPFS_NODE_ACCESSED) {
1260 node->tn_atime = acc->tv_sec;
1261 node->tn_atimensec = acc->tv_nsec;
1263 if (node->tn_status & TMPFS_NODE_MODIFIED) {
1266 node->tn_mtime = mod->tv_sec;
1267 node->tn_mtimensec = mod->tv_nsec;
1269 if (node->tn_status & TMPFS_NODE_CHANGED) {
1270 node->tn_ctime = now.tv_sec;
1271 node->tn_ctimensec = now.tv_nsec;
1274 node->tn_status &= ~(TMPFS_NODE_ACCESSED |
1275 TMPFS_NODE_MODIFIED |
1276 TMPFS_NODE_CHANGED);
1277 TMPFS_NODE_UNLOCK(node);
1280 /* --------------------------------------------------------------------- */
1283 tmpfs_update(struct vnode *vp)
1285 tmpfs_itimes(vp, NULL, NULL);
1288 /* --------------------------------------------------------------------- */
1291 * Caller must hold an exclusive node lock.
1294 tmpfs_truncate(struct vnode *vp, off_t length)
1297 struct tmpfs_node *node;
1299 node = VP_TO_TMPFS_NODE(vp);
1306 if (node->tn_size == length) {
1311 if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
1315 error = tmpfs_reg_resize(vp, length, 1);
1318 node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
1326 /* --------------------------------------------------------------------- */
1329 tmpfs_fetch_ino(struct tmpfs_mount *tmp)
1334 ret = tmp->tm_ino++;
1341 tmpfs_dirtree_compare(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
1343 if (a->td_namelen > b->td_namelen)
1345 else if (a->td_namelen < b->td_namelen)
1348 return strncmp(a->td_name, b->td_name, a->td_namelen);
1352 tmpfs_dirtree_compare_cookie(struct tmpfs_dirent *a, struct tmpfs_dirent *b)