xref: /freebsd/sys/fs/tmpfs/tmpfs.h (revision dc318a4ffabcbfa23bb56a33403aad36e6de30af)
1 /*	$NetBSD: tmpfs.h,v 1.26 2007/02/22 06:37:00 thorpej Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-2-Clause-NetBSD
5  *
6  * Copyright (c) 2005, 2006 The NetBSD Foundation, Inc.
7  * All rights reserved.
8  *
9  * This code is derived from software contributed to The NetBSD Foundation
10  * by Julio M. Merino Vidal, developed as part of Google's Summer of Code
11  * 2005 program.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
23  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
24  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
25  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
26  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32  * POSSIBILITY OF SUCH DAMAGE.
33  *
34  * $FreeBSD$
35  */
36 
37 #ifndef _FS_TMPFS_TMPFS_H_
38 #define _FS_TMPFS_TMPFS_H_
39 
40 #include <sys/cdefs.h>
41 #include <sys/queue.h>
42 #include <sys/tree.h>
43 
44 #ifdef	_SYS_MALLOC_H_
45 MALLOC_DECLARE(M_TMPFSNAME);
46 #endif
47 
48 #define	OBJ_TMPFS	OBJ_PAGERPRIV1	/* has tmpfs vnode allocated */
49 #define	OBJ_TMPFS_VREF	OBJ_PAGERPRIV2	/* vnode is referenced */
50 
51 /*
52  * Internal representation of a tmpfs directory entry.
53  */
54 
55 LIST_HEAD(tmpfs_dir_duphead, tmpfs_dirent);
56 
57 struct tmpfs_dirent {
58 	/*
59 	 * Depending on td_cookie flag entry can be of 3 types:
60 	 * - regular -- no hash collisions, stored in RB-Tree
61 	 * - duphead -- synthetic linked list head for dup entries
62 	 * - dup -- stored in linked list instead of RB-Tree
63 	 */
64 	union {
65 		/* regular and duphead entry types */
66 		RB_ENTRY(tmpfs_dirent)		td_entries;
67 
68 		/* dup entry type */
69 		struct {
70 			LIST_ENTRY(tmpfs_dirent) entries;
71 			LIST_ENTRY(tmpfs_dirent) index_entries;
72 		} td_dup;
73 	} uh;
74 
75 	uint32_t			td_cookie;
76 	uint32_t			td_hash;
77 	u_int				td_namelen;
78 
79 	/*
80 	 * Pointer to the node this entry refers to.  In case this field
81 	 * is NULL, the node is a whiteout.
82 	 */
83 	struct tmpfs_node *		td_node;
84 
85 	union {
86 		/*
87 		 * The name of the entry, allocated from a string pool.  This
88 		 * string is not required to be zero-terminated.
89 		 */
90 		char *			td_name;	/* regular, dup */
91 		struct tmpfs_dir_duphead td_duphead;	/* duphead */
92 	} ud;
93 };
94 
95 /*
96  * A directory in tmpfs holds a collection of directory entries, which
97  * in turn point to other files (which can be directories themselves).
98  *
99  * In tmpfs, this collection is managed by a RB-Tree, whose head is
100  * defined by the struct tmpfs_dir type.
101  *
102  * It is important to notice that directories do not have entries for . and
103  * .. as other file systems do.  These can be generated when requested
104  * based on information available by other means, such as the pointer to
105  * the node itself in the former case or the pointer to the parent directory
106  * in the latter case.  This is done to simplify tmpfs's code and, more
107  * importantly, to remove redundancy.
108  */
109 RB_HEAD(tmpfs_dir, tmpfs_dirent);
110 
111 /*
112  * Each entry in a directory has a cookie that identifies it.  Cookies
113  * supersede offsets within directories because, given how tmpfs stores
114  * directories in memory, there is no such thing as an offset.
115  *
116  * The '.', '..' and the end of directory markers have fixed cookies which
117  * cannot collide with the cookies generated by other entries.  The cookies
118  * for the other entries are generated based on the file name hash value or
119  * unique number in case of name hash collision.
120  *
121  * To preserve compatibility cookies are limited to 31 bits.
122  */
123 
124 #define	TMPFS_DIRCOOKIE_DOT		0
125 #define	TMPFS_DIRCOOKIE_DOTDOT		1
126 #define	TMPFS_DIRCOOKIE_EOF		2
127 #define	TMPFS_DIRCOOKIE_MASK		((off_t)0x3fffffffU)
128 #define	TMPFS_DIRCOOKIE_MIN		((off_t)0x00000004U)
129 #define	TMPFS_DIRCOOKIE_DUP		((off_t)0x40000000U)
130 #define	TMPFS_DIRCOOKIE_DUPHEAD		((off_t)0x80000000U)
131 #define	TMPFS_DIRCOOKIE_DUP_MIN		TMPFS_DIRCOOKIE_DUP
132 #define	TMPFS_DIRCOOKIE_DUP_MAX		\
133 	(TMPFS_DIRCOOKIE_DUP | TMPFS_DIRCOOKIE_MASK)
134 
135 /*
136  * Internal representation of a tmpfs file system node.
137  *
138  * This structure is splitted in two parts: one holds attributes common
139  * to all file types and the other holds data that is only applicable to
140  * a particular type.  The code must be careful to only access those
141  * attributes that are actually allowed by the node's type.
142  *
143  * Below is the key of locks used to protected the fields in the following
144  * structures.
145  * (v)  vnode lock in exclusive mode
146  * (vi) vnode lock in exclusive mode, or vnode lock in shared vnode and
147  *	tn_interlock
148  * (i)  tn_interlock
149  * (m)  tmpfs_mount tm_allnode_lock
150  * (c)  stable after creation
151  */
152 struct tmpfs_node {
153 	/*
154 	 * Doubly-linked list entry which links all existing nodes for
155 	 * a single file system.  This is provided to ease the removal
156 	 * of all nodes during the unmount operation, and to support
157 	 * the implementation of VOP_VNTOCNP().  tn_attached is false
158 	 * when the node is removed from list and unlocked.
159 	 */
160 	LIST_ENTRY(tmpfs_node)	tn_entries;	/* (m) */
161 
162 	/* Node identifier. */
163 	ino_t			tn_id;		/* (c) */
164 
165 	/*
166 	 * The node's type.  Any of 'VBLK', 'VCHR', 'VDIR', 'VFIFO',
167 	 * 'VLNK', 'VREG' and 'VSOCK' is allowed.  The usage of vnode
168 	 * types instead of a custom enumeration is to make things simpler
169 	 * and faster, as we do not need to convert between two types.
170 	 */
171 	enum vtype		tn_type;	/* (c) */
172 
173 	/*
174 	 * See the top comment. Reordered here to fill LP64 hole.
175 	 */
176 	bool			tn_attached;	/* (m) */
177 
178 	/*
179 	 * Node's internal status.  This is used by several file system
180 	 * operations to do modifications to the node in a delayed
181 	 * fashion.
182 	 *
183 	 * tn_accessed has a dedicated byte to allow update by store without
184 	 * using atomics.  This provides a micro-optimization to e.g.
185 	 * tmpfs_read_pgcache().
186 	 */
187 	uint8_t			tn_status;	/* (vi) */
188 	uint8_t			tn_accessed;	/* unlocked */
189 
190 	/*
191 	 * The node size.  It does not necessarily match the real amount
192 	 * of memory consumed by it.
193 	 */
194 	off_t			tn_size;	/* (v) */
195 
196 	/* Generic node attributes. */
197 	uid_t			tn_uid;		/* (v) */
198 	gid_t			tn_gid;		/* (v) */
199 	mode_t			tn_mode;	/* (v) */
200 	int			tn_links;	/* (v) */
201 	u_long			tn_flags;	/* (v) */
202 	struct timespec		tn_atime;	/* (vi) */
203 	struct timespec		tn_mtime;	/* (vi) */
204 	struct timespec		tn_ctime;	/* (vi) */
205 	struct timespec		tn_birthtime;	/* (v) */
206 	unsigned long		tn_gen;		/* (c) */
207 
208 	/*
209 	 * As there is a single vnode for each active file within the
210 	 * system, care has to be taken to avoid allocating more than one
211 	 * vnode per file.  In order to do this, a bidirectional association
212 	 * is kept between vnodes and nodes.
213 	 *
214 	 * Whenever a vnode is allocated, its v_data field is updated to
215 	 * point to the node it references.  At the same time, the node's
216 	 * tn_vnode field is modified to point to the new vnode representing
217 	 * it.  Further attempts to allocate a vnode for this same node will
218 	 * result in returning a new reference to the value stored in
219 	 * tn_vnode.
220 	 *
221 	 * May be NULL when the node is unused (that is, no vnode has been
222 	 * allocated for it or it has been reclaimed).
223 	 */
224 	struct vnode *		tn_vnode;	/* (i) */
225 
226 	/*
227 	 * Interlock to protect tn_vpstate, and tn_status under shared
228 	 * vnode lock.
229 	 */
230 	struct mtx	tn_interlock;
231 
232 	/*
233 	 * Identify if current node has vnode assiocate with
234 	 * or allocating vnode.
235 	 */
236 	int		tn_vpstate;		/* (i) */
237 
238 	/* Transient refcounter on this node. */
239 	u_int		tn_refcount;		/* 0<->1 (m) + (i) */
240 
241 	/* misc data field for different tn_type node */
242 	union {
243 		/* Valid when tn_type == VBLK || tn_type == VCHR. */
244 		dev_t			tn_rdev;	/* (c) */
245 
246 		/* Valid when tn_type == VDIR. */
247 		struct tn_dir {
248 			/*
249 			 * Pointer to the parent directory.  The root
250 			 * directory has a pointer to itself in this field;
251 			 * this property identifies the root node.
252 			 */
253 			struct tmpfs_node *	tn_parent;
254 
255 			/*
256 			 * Head of a tree that links the contents of
257 			 * the directory together.
258 			 */
259 			struct tmpfs_dir	tn_dirhead;
260 
261 			/*
262 			 * Head of a list the contains fake directory entries
263 			 * heads, i.e. entries with TMPFS_DIRCOOKIE_DUPHEAD
264 			 * flag.
265 			 */
266 			struct tmpfs_dir_duphead tn_dupindex;
267 
268 			/*
269 			 * Number and pointer of the first directory entry
270 			 * returned by the readdir operation if it were
271 			 * called again to continue reading data from the
272 			 * same directory as before.  This is used to speed
273 			 * up reads of long directories, assuming that no
274 			 * more than one read is in progress at a given time.
275 			 * Otherwise, these values are discarded.
276 			 */
277 			off_t			tn_readdir_lastn;
278 			struct tmpfs_dirent *	tn_readdir_lastp;
279 		} tn_dir;
280 
281 		/* Valid when tn_type == VLNK. */
282 		/* The link's target, allocated from a string pool. */
283 		struct tn_link {
284 			char *			tn_link_target;	/* (c) */
285 			char 			tn_link_smr;	/* (c) */
286 		} tn_link;
287 
288 		/* Valid when tn_type == VREG. */
289 		struct tn_reg {
290 			/*
291 			 * The contents of regular files stored in a
292 			 * tmpfs file system are represented by a
293 			 * single anonymous memory object (aobj, for
294 			 * short).  The aobj provides direct access to
295 			 * any position within the file.  It is a task
296 			 * of the memory management subsystem to issue
297 			 * the required page ins or page outs whenever
298 			 * a position within the file is accessed.
299 			 */
300 			vm_object_t		tn_aobj;	/* (c) */
301 			struct tmpfs_mount	*tn_tmp;	/* (c) */
302 		} tn_reg;
303 	} tn_spec;	/* (v) */
304 };
305 LIST_HEAD(tmpfs_node_list, tmpfs_node);
306 
307 #define tn_rdev tn_spec.tn_rdev
308 #define tn_dir tn_spec.tn_dir
309 #define tn_link_target tn_spec.tn_link.tn_link_target
310 #define tn_link_smr tn_spec.tn_link.tn_link_smr
311 #define tn_reg tn_spec.tn_reg
312 #define tn_fifo tn_spec.tn_fifo
313 
314 #define	TMPFS_LINK_MAX INT_MAX
315 
316 #define TMPFS_NODE_LOCK(node) mtx_lock(&(node)->tn_interlock)
317 #define TMPFS_NODE_UNLOCK(node) mtx_unlock(&(node)->tn_interlock)
318 #define TMPFS_NODE_MTX(node) (&(node)->tn_interlock)
319 #define	TMPFS_NODE_ASSERT_LOCKED(node) mtx_assert(TMPFS_NODE_MTX(node), \
320     MA_OWNED)
321 
322 #ifdef INVARIANTS
323 #define TMPFS_ASSERT_LOCKED(node) do {					\
324 		MPASS((node) != NULL);					\
325 		MPASS((node)->tn_vnode != NULL);			\
326 		ASSERT_VOP_LOCKED((node)->tn_vnode, "tmpfs assert");	\
327 	} while (0)
328 #else
329 #define TMPFS_ASSERT_LOCKED(node) (void)0
330 #endif
331 
332 /* tn_vpstate */
333 #define TMPFS_VNODE_ALLOCATING	1
334 #define TMPFS_VNODE_WANT	2
335 #define TMPFS_VNODE_DOOMED	4
336 #define	TMPFS_VNODE_WRECLAIM	8
337 
338 /* tn_status */
339 #define	TMPFS_NODE_MODIFIED	0x01
340 #define	TMPFS_NODE_CHANGED	0x02
341 
342 /*
343  * Internal representation of a tmpfs mount point.
344  */
345 struct tmpfs_mount {
346 	/*
347 	 * Original value of the "size" parameter, for reference purposes,
348 	 * mostly.
349 	 */
350 	off_t			tm_size_max;
351 	/*
352 	 * Maximum number of memory pages available for use by the file
353 	 * system, set during mount time.  This variable must never be
354 	 * used directly as it may be bigger than the current amount of
355 	 * free memory; in the extreme case, it will hold the ULONG_MAX
356 	 * value.
357 	 */
358 	u_long			tm_pages_max;
359 
360 	/* Number of pages in use by the file system. */
361 	u_long			tm_pages_used;
362 
363 	/*
364 	 * Pointer to the node representing the root directory of this
365 	 * file system.
366 	 */
367 	struct tmpfs_node *	tm_root;
368 
369 	/*
370 	 * Maximum number of possible nodes for this file system; set
371 	 * during mount time.  We need a hard limit on the maximum number
372 	 * of nodes to avoid allocating too much of them; their objects
373 	 * cannot be released until the file system is unmounted.
374 	 * Otherwise, we could easily run out of memory by creating lots
375 	 * of empty files and then simply removing them.
376 	 */
377 	ino_t			tm_nodes_max;
378 
379 	/* unrhdr used to allocate inode numbers */
380 	struct unrhdr64		tm_ino_unr;
381 
382 	/* Number of nodes currently that are in use. */
383 	ino_t			tm_nodes_inuse;
384 
385 	/* Refcounter on this struct tmpfs_mount. */
386 	uint64_t		tm_refcount;
387 
388 	/* maximum representable file size */
389 	u_int64_t		tm_maxfilesize;
390 
391 	/*
392 	 * The used list contains all nodes that are currently used by
393 	 * the file system; i.e., they refer to existing files.
394 	 */
395 	struct tmpfs_node_list	tm_nodes_used;
396 
397 	/* All node lock to protect the node list and tmp_pages_used. */
398 	struct mtx		tm_allnode_lock;
399 
400 	/* Read-only status. */
401 	bool			tm_ronly;
402 	/* Do not use namecache. */
403 	bool			tm_nonc;
404 	/* Do not update mtime on writes through mmaped areas. */
405 	bool			tm_nomtime;
406 };
407 #define	TMPFS_LOCK(tm) mtx_lock(&(tm)->tm_allnode_lock)
408 #define	TMPFS_UNLOCK(tm) mtx_unlock(&(tm)->tm_allnode_lock)
409 #define	TMPFS_MP_ASSERT_LOCKED(tm) mtx_assert(&(tm)->tm_allnode_lock, MA_OWNED)
410 
411 /*
412  * This structure maps a file identifier to a tmpfs node.  Used by the
413  * NFS code.
414  */
415 struct tmpfs_fid_data {
416 	ino_t			tfd_id;
417 	unsigned long		tfd_gen;
418 };
419 _Static_assert(sizeof(struct tmpfs_fid_data) <= MAXFIDSZ,
420     "(struct tmpfs_fid_data) is larger than (struct fid).fid_data");
421 
422 struct tmpfs_dir_cursor {
423 	struct tmpfs_dirent	*tdc_current;
424 	struct tmpfs_dirent	*tdc_tree;
425 };
426 
427 #ifdef _KERNEL
428 /*
429  * Prototypes for tmpfs_subr.c.
430  */
431 
432 void	tmpfs_ref_node(struct tmpfs_node *node);
433 int	tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *, enum vtype,
434 	    uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *,
435 	    const char *, dev_t, struct tmpfs_node **);
436 int	tmpfs_fo_close(struct file *fp, struct thread *td);
437 void	tmpfs_free_node(struct tmpfs_mount *, struct tmpfs_node *);
438 bool	tmpfs_free_node_locked(struct tmpfs_mount *, struct tmpfs_node *, bool);
439 void	tmpfs_free_tmp(struct tmpfs_mount *);
440 int	tmpfs_alloc_dirent(struct tmpfs_mount *, struct tmpfs_node *,
441 	    const char *, u_int, struct tmpfs_dirent **);
442 void	tmpfs_free_dirent(struct tmpfs_mount *, struct tmpfs_dirent *);
443 void	tmpfs_dirent_init(struct tmpfs_dirent *, const char *, u_int);
444 void	tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj);
445 int	tmpfs_alloc_vp(struct mount *, struct tmpfs_node *, int,
446 	    struct vnode **);
447 void	tmpfs_free_vp(struct vnode *);
448 int	tmpfs_alloc_file(struct vnode *, struct vnode **, struct vattr *,
449 	    struct componentname *, const char *);
450 void	tmpfs_check_mtime(struct vnode *);
451 void	tmpfs_dir_attach(struct vnode *, struct tmpfs_dirent *);
452 void	tmpfs_dir_detach(struct vnode *, struct tmpfs_dirent *);
453 void	tmpfs_dir_destroy(struct tmpfs_mount *, struct tmpfs_node *);
454 struct tmpfs_dirent *	tmpfs_dir_lookup(struct tmpfs_node *node,
455 			    struct tmpfs_node *f,
456 			    struct componentname *cnp);
457 int	tmpfs_dir_getdents(struct tmpfs_mount *, struct tmpfs_node *,
458 	    struct uio *, int, u_long *, int *);
459 int	tmpfs_dir_whiteout_add(struct vnode *, struct componentname *);
460 void	tmpfs_dir_whiteout_remove(struct vnode *, struct componentname *);
461 int	tmpfs_reg_resize(struct vnode *, off_t, boolean_t);
462 int	tmpfs_chflags(struct vnode *, u_long, struct ucred *, struct thread *);
463 int	tmpfs_chmod(struct vnode *, mode_t, struct ucred *, struct thread *);
464 int	tmpfs_chown(struct vnode *, uid_t, gid_t, struct ucred *,
465 	    struct thread *);
466 int	tmpfs_chsize(struct vnode *, u_quad_t, struct ucred *, struct thread *);
467 int	tmpfs_chtimes(struct vnode *, struct vattr *, struct ucred *cred,
468 	    struct thread *);
469 void	tmpfs_itimes(struct vnode *, const struct timespec *,
470 	    const struct timespec *);
471 
472 void	tmpfs_set_accessed(struct tmpfs_mount *tm, struct tmpfs_node *node);
473 void	tmpfs_set_status(struct tmpfs_mount *tm, struct tmpfs_node *node,
474 	    int status);
475 int	tmpfs_truncate(struct vnode *, off_t);
476 struct tmpfs_dirent *tmpfs_dir_first(struct tmpfs_node *dnode,
477 	    struct tmpfs_dir_cursor *dc);
478 struct tmpfs_dirent *tmpfs_dir_next(struct tmpfs_node *dnode,
479 	    struct tmpfs_dir_cursor *dc);
480 static __inline void
481 tmpfs_update(struct vnode *vp)
482 {
483 
484 	tmpfs_itimes(vp, NULL, NULL);
485 }
486 
487 /*
488  * Convenience macros to simplify some logical expressions.
489  */
490 #define IMPLIES(a, b) (!(a) || (b))
491 #define IFF(a, b) (IMPLIES(a, b) && IMPLIES(b, a))
492 
493 /*
494  * Checks that the directory entry pointed by 'de' matches the name 'name'
495  * with a length of 'len'.
496  */
497 #define TMPFS_DIRENT_MATCHES(de, name, len) \
498     (de->td_namelen == len && \
499     bcmp((de)->ud.td_name, (name), (de)->td_namelen) == 0)
500 
501 /*
502  * Ensures that the node pointed by 'node' is a directory and that its
503  * contents are consistent with respect to directories.
504  */
505 #define TMPFS_VALIDATE_DIR(node) do { \
506 	MPASS((node)->tn_type == VDIR); \
507 	MPASS((node)->tn_size % sizeof(struct tmpfs_dirent) == 0); \
508 } while (0)
509 
510 /*
511  * Amount of memory pages to reserve for the system (e.g., to not use by
512  * tmpfs).
513  */
514 #if !defined(TMPFS_PAGES_MINRESERVED)
515 #define TMPFS_PAGES_MINRESERVED		(4 * 1024 * 1024 / PAGE_SIZE)
516 #endif
517 
518 size_t tmpfs_mem_avail(void);
519 size_t tmpfs_pages_used(struct tmpfs_mount *tmp);
520 int tmpfs_subr_init(void);
521 void tmpfs_subr_uninit(void);
522 
523 extern int tmpfs_pager_type;
524 
525 /*
526  * Macros/functions to convert from generic data structures to tmpfs
527  * specific ones.
528  */
529 
530 static inline struct tmpfs_mount *
531 VFS_TO_TMPFS(struct mount *mp)
532 {
533 	struct tmpfs_mount *tmp;
534 
535 	MPASS(mp != NULL && mp->mnt_data != NULL);
536 	tmp = (struct tmpfs_mount *)mp->mnt_data;
537 	return (tmp);
538 }
539 
540 static inline struct tmpfs_node *
541 VP_TO_TMPFS_NODE(struct vnode *vp)
542 {
543 	struct tmpfs_node *node;
544 
545 	MPASS(vp != NULL && vp->v_data != NULL);
546 	node = (struct tmpfs_node *)vp->v_data;
547 	return (node);
548 }
549 
550 #define	VP_TO_TMPFS_NODE_SMR(vp)	\
551 	((struct tmpfs_node *)vn_load_v_data_smr(vp))
552 
553 static inline struct tmpfs_node *
554 VP_TO_TMPFS_DIR(struct vnode *vp)
555 {
556 	struct tmpfs_node *node;
557 
558 	node = VP_TO_TMPFS_NODE(vp);
559 	TMPFS_VALIDATE_DIR(node);
560 	return (node);
561 }
562 
563 static inline bool
564 tmpfs_use_nc(struct vnode *vp)
565 {
566 
567 	return (!(VFS_TO_TMPFS(vp->v_mount)->tm_nonc));
568 }
569 
570 static inline void
571 tmpfs_update_getattr(struct vnode *vp)
572 {
573 	struct tmpfs_node *node;
574 
575 	node = VP_TO_TMPFS_NODE(vp);
576 	if (__predict_false((node->tn_status & (TMPFS_NODE_MODIFIED |
577 	    TMPFS_NODE_CHANGED)) != 0 || node->tn_accessed))
578 		tmpfs_update(vp);
579 }
580 
581 extern struct fileops tmpfs_fnops;
582 
583 #endif /* _KERNEL */
584 
585 #endif /* _FS_TMPFS_TMPFS_H_ */
586