1 /* $NetBSD: tmpfs.h,v 1.26 2007/02/22 06:37:00 thorpej Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-2-Clause
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
35 #ifndef _FS_TMPFS_TMPFS_H_
36 #define _FS_TMPFS_TMPFS_H_
37
38 #include <sys/cdefs.h>
39 #include <sys/queue.h>
40 #include <sys/tree.h>
41
42 #ifdef _SYS_MALLOC_H_
43 MALLOC_DECLARE(M_TMPFSNAME);
44 #endif
45
46 #define OBJ_TMPFS OBJ_PAGERPRIV1 /* has tmpfs vnode allocated */
47 #define OBJ_TMPFS_VREF OBJ_PAGERPRIV2 /* vnode is referenced */
48
49 /*
50 * Internal representation of a tmpfs directory entry.
51 */
52
53 LIST_HEAD(tmpfs_dir_duphead, tmpfs_dirent);
54
55 struct tmpfs_dirent {
56 /*
57 * Depending on td_cookie flag entry can be of 3 types:
58 * - regular -- no hash collisions, stored in RB-Tree
59 * - duphead -- synthetic linked list head for dup entries
60 * - dup -- stored in linked list instead of RB-Tree
61 */
62 union {
63 /* regular and duphead entry types */
64 RB_ENTRY(tmpfs_dirent) td_entries;
65
66 /* dup entry type */
67 struct {
68 LIST_ENTRY(tmpfs_dirent) entries;
69 LIST_ENTRY(tmpfs_dirent) index_entries;
70 } td_dup;
71 } uh;
72
73 uint32_t td_cookie;
74 uint32_t td_hash;
75 u_int td_namelen;
76
77 /*
78 * Pointer to the node this entry refers to. In case this field
79 * is NULL, the node is a whiteout.
80 */
81 struct tmpfs_node * td_node;
82
83 union {
84 /*
85 * The name of the entry, allocated from a string pool. This
86 * string is not required to be zero-terminated.
87 */
88 char * td_name; /* regular, dup */
89 struct tmpfs_dir_duphead td_duphead; /* duphead */
90 } ud;
91 };
92
93 /*
94 * A directory in tmpfs holds a collection of directory entries, which
95 * in turn point to other files (which can be directories themselves).
96 *
97 * In tmpfs, this collection is managed by a RB-Tree, whose head is
98 * defined by the struct tmpfs_dir type.
99 *
100 * It is important to notice that directories do not have entries for . and
101 * .. as other file systems do. These can be generated when requested
102 * based on information available by other means, such as the pointer to
103 * the node itself in the former case or the pointer to the parent directory
104 * in the latter case. This is done to simplify tmpfs's code and, more
105 * importantly, to remove redundancy.
106 */
107 RB_HEAD(tmpfs_dir, tmpfs_dirent);
108
109 /*
110 * Each entry in a directory has a cookie that identifies it. Cookies
111 * supersede offsets within directories because, given how tmpfs stores
112 * directories in memory, there is no such thing as an offset.
113 *
114 * The '.', '..' and the end of directory markers have fixed cookies which
115 * cannot collide with the cookies generated by other entries. The cookies
116 * for the other entries are generated based on the file name hash value or
117 * unique number in case of name hash collision.
118 *
119 * To preserve compatibility cookies are limited to 31 bits.
120 */
121
122 #define TMPFS_DIRCOOKIE_DOT 0
123 #define TMPFS_DIRCOOKIE_DOTDOT 1
124 #define TMPFS_DIRCOOKIE_EOF 2
125 #define TMPFS_DIRCOOKIE_MASK ((off_t)0x3fffffffU)
126 #define TMPFS_DIRCOOKIE_MIN ((off_t)0x00000004U)
127 #define TMPFS_DIRCOOKIE_DUP ((off_t)0x40000000U)
128 #define TMPFS_DIRCOOKIE_DUPHEAD ((off_t)0x80000000U)
129 #define TMPFS_DIRCOOKIE_DUP_MIN TMPFS_DIRCOOKIE_DUP
130 #define TMPFS_DIRCOOKIE_DUP_MAX \
131 (TMPFS_DIRCOOKIE_DUP | TMPFS_DIRCOOKIE_MASK)
132
133 /*
134 * Internal representation of a tmpfs extended attribute entry.
135 */
136 LIST_HEAD(tmpfs_extattr_list, tmpfs_extattr);
137
138 struct tmpfs_extattr {
139 LIST_ENTRY(tmpfs_extattr) ea_extattrs;
140 int ea_namespace; /* attr namespace */
141 char *ea_name; /* attr name */
142 unsigned char ea_namelen; /* attr name length */
143 char *ea_value; /* attr value buffer */
144 ssize_t ea_size; /* attr value size */
145 };
146
147 /*
148 * Internal representation of a tmpfs file system node.
149 *
150 * This structure is splitted in two parts: one holds attributes common
151 * to all file types and the other holds data that is only applicable to
152 * a particular type. The code must be careful to only access those
153 * attributes that are actually allowed by the node's type.
154 *
155 * Below is the key of locks used to protected the fields in the following
156 * structures.
157 * (v) vnode lock in exclusive mode
158 * (vi) vnode lock in exclusive mode, or vnode lock in shared vnode and
159 * tn_interlock
160 * (i) tn_interlock
161 * (m) tmpfs_mount tm_allnode_lock
162 * (c) stable after creation
163 * (v) tn_reg.tn_aobj vm_object lock
164 */
165 struct tmpfs_node {
166 /*
167 * Doubly-linked list entry which links all existing nodes for
168 * a single file system. This is provided to ease the removal
169 * of all nodes during the unmount operation, and to support
170 * the implementation of VOP_VNTOCNP(). tn_attached is false
171 * when the node is removed from list and unlocked.
172 */
173 LIST_ENTRY(tmpfs_node) tn_entries; /* (m) */
174
175 /* Node identifier. */
176 ino_t tn_id; /* (c) */
177
178 /*
179 * The node's type. Any of 'VBLK', 'VCHR', 'VDIR', 'VFIFO',
180 * 'VLNK', 'VREG' and 'VSOCK' is allowed. The usage of vnode
181 * types instead of a custom enumeration is to make things simpler
182 * and faster, as we do not need to convert between two types.
183 */
184 __enum_uint8(vtype) tn_type; /* (c) */
185
186 /*
187 * See the top comment. Reordered here to fill LP64 hole.
188 */
189 bool tn_attached; /* (m) */
190
191 /*
192 * Node's internal status. This is used by several file system
193 * operations to do modifications to the node in a delayed
194 * fashion.
195 *
196 * tn_accessed has a dedicated byte to allow update by store without
197 * using atomics. This provides a micro-optimization to e.g.
198 * tmpfs_read_pgcache().
199 */
200 uint8_t tn_status; /* (vi) */
201 uint8_t tn_accessed; /* unlocked */
202
203 /*
204 * The node size. It does not necessarily match the real amount
205 * of memory consumed by it.
206 */
207 off_t tn_size; /* (v) */
208
209 /* Generic node attributes. */
210 uid_t tn_uid; /* (v) */
211 gid_t tn_gid; /* (v) */
212 mode_t tn_mode; /* (v) */
213 int tn_links; /* (v) */
214 u_long tn_flags; /* (v) */
215 struct timespec tn_atime; /* (vi) */
216 struct timespec tn_mtime; /* (vi) */
217 struct timespec tn_ctime; /* (vi) */
218 struct timespec tn_birthtime; /* (v) */
219 unsigned long tn_gen; /* (c) */
220
221 /*
222 * As there is a single vnode for each active file within the
223 * system, care has to be taken to avoid allocating more than one
224 * vnode per file. In order to do this, a bidirectional association
225 * is kept between vnodes and nodes.
226 *
227 * Whenever a vnode is allocated, its v_data field is updated to
228 * point to the node it references. At the same time, the node's
229 * tn_vnode field is modified to point to the new vnode representing
230 * it. Further attempts to allocate a vnode for this same node will
231 * result in returning a new reference to the value stored in
232 * tn_vnode.
233 *
234 * May be NULL when the node is unused (that is, no vnode has been
235 * allocated for it or it has been reclaimed).
236 */
237 struct vnode * tn_vnode; /* (i) */
238
239 /*
240 * Interlock to protect tn_vpstate, and tn_status under shared
241 * vnode lock.
242 */
243 struct mtx tn_interlock;
244
245 /*
246 * Identify if current node has vnode assiocate with
247 * or allocating vnode.
248 */
249 int tn_vpstate; /* (i) */
250
251 /* Transient refcounter on this node. */
252 u_int tn_refcount; /* 0<->1 (m) + (i) */
253
254 /* Extended attributes of this node. */
255 struct tmpfs_extattr_list tn_extattrs; /* (v) */
256
257 /* misc data field for different tn_type node */
258 union {
259 /* Valid when tn_type == VBLK || tn_type == VCHR. */
260 dev_t tn_rdev; /* (c) */
261
262 /* Valid when tn_type == VDIR. */
263 struct tn_dir {
264 /*
265 * Pointer to the parent directory. The root
266 * directory has a pointer to itself in this field;
267 * this property identifies the root node.
268 */
269 struct tmpfs_node * tn_parent;
270
271 /*
272 * Head of a tree that links the contents of
273 * the directory together.
274 */
275 struct tmpfs_dir tn_dirhead;
276
277 /*
278 * Head of a list the contains fake directory entries
279 * heads, i.e. entries with TMPFS_DIRCOOKIE_DUPHEAD
280 * flag.
281 */
282 struct tmpfs_dir_duphead tn_dupindex;
283
284 /*
285 * Number and pointer of the first directory entry
286 * returned by the readdir operation if it were
287 * called again to continue reading data from the
288 * same directory as before. This is used to speed
289 * up reads of long directories, assuming that no
290 * more than one read is in progress at a given time.
291 * Otherwise, these values are discarded.
292 */
293 off_t tn_readdir_lastn;
294 struct tmpfs_dirent * tn_readdir_lastp;
295
296 /*
297 * Total size of whiteout directory entries. This
298 * must be a multiple of sizeof(struct tmpfs_dirent)
299 * and is used to determine whether a directory is
300 * empty (excluding whiteout entries) during rename/
301 * rmdir operations.
302 */
303 off_t tn_wht_size; /* (v) */
304 } tn_dir;
305
306 /* Valid when tn_type == VLNK. */
307 /* The link's target, allocated from a string pool. */
308 struct tn_link {
309 char * tn_link_target; /* (c) */
310 char tn_link_smr; /* (c) */
311 } tn_link;
312
313 /* Valid when tn_type == VREG. */
314 struct tn_reg {
315 /*
316 * The contents of regular files stored in a
317 * tmpfs file system are represented by a
318 * single anonymous memory object (aobj, for
319 * short). The aobj provides direct access to
320 * any position within the file. It is a task
321 * of the memory management subsystem to issue
322 * the required page ins or page outs whenever
323 * a position within the file is accessed.
324 */
325 vm_object_t tn_aobj; /* (c) */
326 struct tmpfs_mount *tn_tmp; /* (c) */
327 vm_pindex_t tn_pages; /* (v) */
328 } tn_reg;
329 } tn_spec; /* (v) */
330 };
331 LIST_HEAD(tmpfs_node_list, tmpfs_node);
332
333 #define tn_rdev tn_spec.tn_rdev
334 #define tn_dir tn_spec.tn_dir
335 #define tn_link_target tn_spec.tn_link.tn_link_target
336 #define tn_link_smr tn_spec.tn_link.tn_link_smr
337 #define tn_reg tn_spec.tn_reg
338 #define tn_fifo tn_spec.tn_fifo
339
340 #define TMPFS_LINK_MAX INT_MAX
341
342 #define TMPFS_NODE_LOCK(node) mtx_lock(&(node)->tn_interlock)
343 #define TMPFS_NODE_UNLOCK(node) mtx_unlock(&(node)->tn_interlock)
344 #define TMPFS_NODE_MTX(node) (&(node)->tn_interlock)
345 #define TMPFS_NODE_ASSERT_LOCKED(node) mtx_assert(TMPFS_NODE_MTX(node), \
346 MA_OWNED)
347
348 #ifdef INVARIANTS
349 #define TMPFS_ASSERT_LOCKED(node) do { \
350 MPASS((node) != NULL); \
351 MPASS((node)->tn_vnode != NULL); \
352 ASSERT_VOP_LOCKED((node)->tn_vnode, "tmpfs assert"); \
353 } while (0)
354 #else
355 #define TMPFS_ASSERT_LOCKED(node) (void)0
356 #endif
357
358 /* tn_vpstate */
359 #define TMPFS_VNODE_ALLOCATING 1
360 #define TMPFS_VNODE_WANT 2
361 #define TMPFS_VNODE_DOOMED 4
362 #define TMPFS_VNODE_WRECLAIM 8
363
364 /* tn_status */
365 #define TMPFS_NODE_MODIFIED 0x01
366 #define TMPFS_NODE_CHANGED 0x02
367
368 /*
369 * Internal representation of a tmpfs mount point.
370 */
371 struct tmpfs_mount {
372 /*
373 * Original value of the "size" parameter, for reference purposes,
374 * mostly.
375 */
376 off_t tm_size_max;
377 /*
378 * Maximum number of memory pages available for use by the file
379 * system, set during mount time. This variable must never be
380 * used directly as it may be bigger than the current amount of
381 * free memory; in the extreme case, it will hold the ULONG_MAX
382 * value.
383 */
384 u_long tm_pages_max;
385
386 /* Number of pages in use by the file system. */
387 u_long tm_pages_used;
388
389 /*
390 * Pointer to the node representing the root directory of this
391 * file system.
392 */
393 struct tmpfs_node * tm_root;
394
395 /*
396 * Maximum number of possible nodes for this file system; set
397 * during mount time. We need a hard limit on the maximum number
398 * of nodes to avoid allocating too much of them; their objects
399 * cannot be released until the file system is unmounted.
400 * Otherwise, we could easily run out of memory by creating lots
401 * of empty files and then simply removing them.
402 */
403 ino_t tm_nodes_max;
404
405 /* unrhdr used to allocate inode numbers */
406 struct unrhdr64 tm_ino_unr;
407
408 /* Number of nodes currently that are in use. */
409 ino_t tm_nodes_inuse;
410
411 /* Memory used by extended attributes */
412 uint64_t tm_ea_memory_inuse;
413
414 /* Maximum memory available for extended attributes */
415 uint64_t tm_ea_memory_max;
416
417 /* Refcounter on this struct tmpfs_mount. */
418 uint64_t tm_refcount;
419
420 /* maximum representable file size */
421 u_int64_t tm_maxfilesize;
422
423 /*
424 * The used list contains all nodes that are currently used by
425 * the file system; i.e., they refer to existing files.
426 */
427 struct tmpfs_node_list tm_nodes_used;
428
429 /* All node lock to protect the node list and tmp_pages_used. */
430 struct mtx tm_allnode_lock;
431
432 /* Read-only status. */
433 bool tm_ronly;
434 /* Do not use namecache. */
435 bool tm_nonc;
436 /* Do not update mtime on writes through mmaped areas. */
437 bool tm_nomtime;
438
439 /* Read from page cache directly. */
440 bool tm_pgread;
441 };
442 #define TMPFS_LOCK(tm) mtx_lock(&(tm)->tm_allnode_lock)
443 #define TMPFS_UNLOCK(tm) mtx_unlock(&(tm)->tm_allnode_lock)
444 #define TMPFS_MP_ASSERT_LOCKED(tm) mtx_assert(&(tm)->tm_allnode_lock, MA_OWNED)
445
446 /*
447 * This structure maps a file identifier to a tmpfs node. Used by the
448 * NFS code.
449 */
450 struct tmpfs_fid_data {
451 ino_t tfd_id;
452 unsigned long tfd_gen;
453 };
454 _Static_assert(sizeof(struct tmpfs_fid_data) <= MAXFIDSZ,
455 "(struct tmpfs_fid_data) is larger than (struct fid).fid_data");
456
457 struct tmpfs_dir_cursor {
458 struct tmpfs_dirent *tdc_current;
459 struct tmpfs_dirent *tdc_tree;
460 };
461
462 #ifdef _KERNEL
463 /*
464 * Prototypes for tmpfs_subr.c.
465 */
466
467 void tmpfs_ref_node(struct tmpfs_node *node);
468 int tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *, __enum_uint8(vtype),
469 uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *,
470 const char *, dev_t, struct tmpfs_node **);
471 int tmpfs_fo_close(struct file *fp, struct thread *td);
472 void tmpfs_free_node(struct tmpfs_mount *, struct tmpfs_node *);
473 bool tmpfs_free_node_locked(struct tmpfs_mount *, struct tmpfs_node *, bool);
474 void tmpfs_free_tmp(struct tmpfs_mount *);
475 int tmpfs_alloc_dirent(struct tmpfs_mount *, struct tmpfs_node *,
476 const char *, u_int, struct tmpfs_dirent **);
477 void tmpfs_free_dirent(struct tmpfs_mount *, struct tmpfs_dirent *);
478 void tmpfs_dirent_init(struct tmpfs_dirent *, const char *, u_int);
479 void tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj);
480 int tmpfs_alloc_vp(struct mount *, struct tmpfs_node *, int,
481 struct vnode **);
482 void tmpfs_free_vp(struct vnode *);
483 int tmpfs_alloc_file(struct vnode *, struct vnode **, struct vattr *,
484 struct componentname *, const char *);
485 void tmpfs_check_mtime(struct vnode *);
486 void tmpfs_dir_attach(struct vnode *, struct tmpfs_dirent *);
487 void tmpfs_dir_detach(struct vnode *, struct tmpfs_dirent *);
488 void tmpfs_dir_destroy(struct tmpfs_mount *, struct tmpfs_node *);
489 struct tmpfs_dirent * tmpfs_dir_lookup(struct tmpfs_node *node,
490 struct tmpfs_node *f,
491 struct componentname *cnp);
492 int tmpfs_dir_getdents(struct tmpfs_mount *, struct tmpfs_node *,
493 struct uio *, int, uint64_t *, int *);
494 int tmpfs_dir_whiteout_add(struct vnode *, struct componentname *);
495 void tmpfs_dir_whiteout_remove(struct vnode *, struct componentname *);
496 void tmpfs_dir_clear_whiteouts(struct vnode *);
497 int tmpfs_reg_resize(struct vnode *, off_t, boolean_t);
498 int tmpfs_reg_punch_hole(struct vnode *vp, off_t *, off_t *);
499 int tmpfs_chflags(struct vnode *, u_long, struct ucred *, struct thread *);
500 int tmpfs_chmod(struct vnode *, mode_t, struct ucred *, struct thread *);
501 int tmpfs_chown(struct vnode *, uid_t, gid_t, struct ucred *,
502 struct thread *);
503 int tmpfs_chsize(struct vnode *, u_quad_t, struct ucred *, struct thread *);
504 int tmpfs_chtimes(struct vnode *, struct vattr *, struct ucred *cred,
505 struct thread *);
506 void tmpfs_itimes(struct vnode *, const struct timespec *,
507 const struct timespec *);
508
509 void tmpfs_set_accessed(struct tmpfs_mount *tm, struct tmpfs_node *node);
510 void tmpfs_set_status(struct tmpfs_mount *tm, struct tmpfs_node *node,
511 int status);
512 int tmpfs_truncate(struct vnode *, off_t);
513 struct tmpfs_dirent *tmpfs_dir_first(struct tmpfs_node *dnode,
514 struct tmpfs_dir_cursor *dc);
515 struct tmpfs_dirent *tmpfs_dir_next(struct tmpfs_node *dnode,
516 struct tmpfs_dir_cursor *dc);
517 bool tmpfs_pages_check_avail(struct tmpfs_mount *tmp, size_t req_pages);
518 void tmpfs_extattr_free(struct tmpfs_extattr* ea);
519 static __inline void
tmpfs_update(struct vnode * vp)520 tmpfs_update(struct vnode *vp)
521 {
522
523 tmpfs_itimes(vp, NULL, NULL);
524 }
525
526 /*
527 * Convenience macros to simplify some logical expressions.
528 */
529 #define IMPLIES(a, b) (!(a) || (b))
530
531 /*
532 * Checks that the directory entry pointed by 'de' matches the name 'name'
533 * with a length of 'len'.
534 */
535 #define TMPFS_DIRENT_MATCHES(de, name, len) \
536 (de->td_namelen == len && \
537 bcmp((de)->ud.td_name, (name), (de)->td_namelen) == 0)
538
539 /*
540 * Ensures that the node pointed by 'node' is a directory and that its
541 * contents are consistent with respect to directories.
542 */
543 #define TMPFS_VALIDATE_DIR(node) do { \
544 MPASS((node)->tn_type == VDIR); \
545 MPASS((node)->tn_size % sizeof(struct tmpfs_dirent) == 0); \
546 MPASS((node)->tn_dir.tn_wht_size % sizeof(struct tmpfs_dirent) == 0); \
547 MPASS((node)->tn_dir.tn_wht_size <= (node)->tn_size); \
548 } while (0)
549
550 /*
551 * Amount of memory pages to reserve for the system (e.g., to not use by
552 * tmpfs).
553 */
554 #if !defined(TMPFS_PAGES_MINRESERVED)
555 #define TMPFS_PAGES_MINRESERVED (4 * 1024 * 1024 / PAGE_SIZE)
556 #endif
557
558 /*
559 * Percent of available memory + swap available to use by tmpfs file systems
560 * without a size limit.
561 */
562 #if !defined(TMPFS_MEM_PERCENT)
563 #define TMPFS_MEM_PERCENT 100
564 #endif
565
566 /*
567 * Amount of memory to reserve for extended attributes.
568 */
569 #if !defined(TMPFS_EA_MEMORY_RESERVED)
570 #define TMPFS_EA_MEMORY_RESERVED (16 * 1024 * 1024)
571 #endif
572
573 size_t tmpfs_mem_avail(void);
574 size_t tmpfs_pages_used(struct tmpfs_mount *tmp);
575 int tmpfs_subr_init(void);
576 void tmpfs_subr_uninit(void);
577
578 extern int tmpfs_pager_type;
579
580 /*
581 * Macros/functions to convert from generic data structures to tmpfs
582 * specific ones.
583 */
584
585 static inline struct vnode *
VM_TO_TMPFS_VP(vm_object_t obj)586 VM_TO_TMPFS_VP(vm_object_t obj)
587 {
588 struct tmpfs_node *node;
589
590 if ((obj->flags & OBJ_TMPFS) == 0)
591 return (NULL);
592
593 /*
594 * swp_priv is the back-pointer to the tmpfs node, if any,
595 * which uses the vm object as backing store. The object
596 * handle is not used to avoid locking sw_alloc_sx on tmpfs
597 * node instantiation/destroy.
598 */
599 node = obj->un_pager.swp.swp_priv;
600 return (node->tn_vnode);
601 }
602
603 static inline struct tmpfs_mount *
VM_TO_TMPFS_MP(vm_object_t obj)604 VM_TO_TMPFS_MP(vm_object_t obj)
605 {
606 struct tmpfs_node *node;
607
608 if ((obj->flags & OBJ_TMPFS) == 0)
609 return (NULL);
610
611 node = obj->un_pager.swp.swp_priv;
612 MPASS(node->tn_type == VREG);
613 return (node->tn_reg.tn_tmp);
614 }
615
616 static inline struct tmpfs_mount *
VFS_TO_TMPFS(struct mount * mp)617 VFS_TO_TMPFS(struct mount *mp)
618 {
619 struct tmpfs_mount *tmp;
620
621 MPASS(mp != NULL && mp->mnt_data != NULL);
622 tmp = (struct tmpfs_mount *)mp->mnt_data;
623 return (tmp);
624 }
625
626 static inline struct tmpfs_node *
VP_TO_TMPFS_NODE(struct vnode * vp)627 VP_TO_TMPFS_NODE(struct vnode *vp)
628 {
629 struct tmpfs_node *node;
630
631 MPASS(vp != NULL && vp->v_data != NULL);
632 node = (struct tmpfs_node *)vp->v_data;
633 return (node);
634 }
635
636 #define VP_TO_TMPFS_NODE_SMR(vp) \
637 ((struct tmpfs_node *)vn_load_v_data_smr(vp))
638
639 static inline struct tmpfs_node *
VP_TO_TMPFS_DIR(struct vnode * vp)640 VP_TO_TMPFS_DIR(struct vnode *vp)
641 {
642 struct tmpfs_node *node;
643
644 node = VP_TO_TMPFS_NODE(vp);
645 TMPFS_VALIDATE_DIR(node);
646 return (node);
647 }
648
649 static inline bool
tmpfs_use_nc(struct vnode * vp)650 tmpfs_use_nc(struct vnode *vp)
651 {
652
653 return (!(VFS_TO_TMPFS(vp->v_mount)->tm_nonc));
654 }
655
656 static inline void
tmpfs_update_getattr(struct vnode * vp)657 tmpfs_update_getattr(struct vnode *vp)
658 {
659 struct tmpfs_node *node;
660
661 node = VP_TO_TMPFS_NODE(vp);
662 if (__predict_false((node->tn_status & (TMPFS_NODE_MODIFIED |
663 TMPFS_NODE_CHANGED)) != 0 || node->tn_accessed))
664 tmpfs_update(vp);
665 }
666
667 extern struct fileops tmpfs_fnops;
668
669 #endif /* _KERNEL */
670
671 #endif /* _FS_TMPFS_TMPFS_H_ */
672