1 | /* $NetBSD: tmpfs.h,v 1.52 2015/07/06 10:07:12 hannken Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (c) 2005, 2006, 2007 The NetBSD Foundation, Inc. |
5 | * All rights reserved. |
6 | * |
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 |
9 | * 2005 program. |
10 | * |
11 | * Redistribution and use in source and binary forms, with or without |
12 | * modification, are permitted provided that the following conditions |
13 | * are met: |
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. |
19 | * |
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. |
31 | */ |
32 | |
33 | #ifndef _FS_TMPFS_TMPFS_H_ |
34 | #define _FS_TMPFS_TMPFS_H_ |
35 | |
36 | #if !defined(_KERNEL) && !defined(_KMEMUSER) |
37 | #error "not supposed to be exposed to userland" |
38 | #endif |
39 | |
40 | #include <sys/dirent.h> |
41 | #include <sys/mount.h> |
42 | #include <sys/pool.h> |
43 | #include <sys/queue.h> |
44 | #include <sys/vnode.h> |
45 | |
46 | /* |
47 | * Internal representation of a tmpfs directory entry. |
48 | * |
49 | * All fields are protected by vnode lock. |
50 | */ |
51 | typedef struct tmpfs_dirent { |
52 | TAILQ_ENTRY(tmpfs_dirent) td_entries; |
53 | |
54 | /* Pointer to the inode this entry refers to. */ |
55 | struct tmpfs_node * td_node; |
56 | |
57 | /* Sequence number, see tmpfs_dir_getseq(). */ |
58 | uint32_t td_seq; |
59 | |
60 | /* Name and its length. */ |
61 | char * td_name; |
62 | uint16_t td_namelen; |
63 | } tmpfs_dirent_t; |
64 | |
65 | TAILQ_HEAD(tmpfs_dir, tmpfs_dirent); |
66 | |
67 | /* |
68 | * Internal representation of a tmpfs file system node -- inode. |
69 | * |
70 | * This structure is split in two parts: one holds attributes common |
71 | * to all file types and the other holds data that is only applicable to |
72 | * a particular type. |
73 | * |
74 | * All fields are protected by vnode lock. The vnode association itself |
75 | * is protected by vcache. |
76 | */ |
77 | typedef struct tmpfs_node { |
78 | LIST_ENTRY(tmpfs_node) tn_entries; |
79 | |
80 | /* |
81 | * Each inode has a corresponding vnode. It is a bi-directional |
82 | * association. Whenever vnode is allocated, its v_data field is |
83 | * set to the inode it reference, and tmpfs_node_t::tn_vnode is |
84 | * set to point to the said vnode. |
85 | * |
86 | * Further attempts to allocate a vnode for this same node will |
87 | * result in returning a new reference to the value stored in |
88 | * tn_vnode. It may be NULL when the node is unused (that is, |
89 | * no vnode has been allocated or it has been reclaimed). |
90 | */ |
91 | vnode_t * tn_vnode; |
92 | |
93 | /* Prevent node from being reclaimed. */ |
94 | uint32_t tn_holdcount; |
95 | |
96 | /* Directory entry. Only a hint, since hard link can have multiple. */ |
97 | tmpfs_dirent_t * tn_dirent_hint; |
98 | |
99 | /* The inode type: VBLK, VCHR, VDIR, VFIFO, VLNK, VREG or VSOCK. */ |
100 | enum vtype tn_type; |
101 | |
102 | /* Inode identifier and generation number. */ |
103 | ino_t tn_id; |
104 | uint32_t tn_gen; |
105 | |
106 | /* The inode size. */ |
107 | off_t tn_size; |
108 | |
109 | /* Generic node attributes. */ |
110 | uid_t tn_uid; |
111 | gid_t tn_gid; |
112 | mode_t tn_mode; |
113 | int tn_flags; |
114 | nlink_t tn_links; |
115 | struct timespec tn_atime; |
116 | struct timespec tn_mtime; |
117 | struct timespec tn_ctime; |
118 | struct timespec tn_birthtime; |
119 | |
120 | /* Head of byte-level lock list (used by tmpfs_advlock). */ |
121 | struct lockf * tn_lockf; |
122 | |
123 | union { |
124 | /* Type case: VBLK or VCHR. */ |
125 | struct { |
126 | dev_t tn_rdev; |
127 | } tn_dev; |
128 | |
129 | /* Type case: VDIR. */ |
130 | struct { |
131 | /* Parent directory (root inode points to itself). */ |
132 | struct tmpfs_node * tn_parent; |
133 | |
134 | /* List of directory entries. */ |
135 | struct tmpfs_dir tn_dir; |
136 | |
137 | /* Last given sequence number and their arena. */ |
138 | uint32_t tn_next_seq; |
139 | void * tn_seq_arena; |
140 | |
141 | /* |
142 | * Pointer of the last directory entry returned |
143 | * by the readdir(3) operation. |
144 | */ |
145 | struct tmpfs_dirent * tn_readdir_lastp; |
146 | } tn_dir; |
147 | |
148 | /* Type case: VLNK. */ |
149 | struct tn_lnk { |
150 | /* The link's target. */ |
151 | char * tn_link; |
152 | } tn_lnk; |
153 | |
154 | /* Type case: VREG. */ |
155 | struct tn_reg { |
156 | /* Underlying UVM object to store contents. */ |
157 | struct uvm_object * tn_aobj; |
158 | size_t tn_aobj_pages; |
159 | } tn_reg; |
160 | } tn_spec; |
161 | } tmpfs_node_t; |
162 | |
163 | #if defined(_KERNEL) |
164 | |
165 | VFS_PROTOS(tmpfs); |
166 | |
167 | LIST_HEAD(tmpfs_node_list, tmpfs_node); |
168 | |
169 | #define TMPFS_MAXNAMLEN 255 |
170 | /* Validate maximum td_namelen length. */ |
171 | CTASSERT(TMPFS_MAXNAMLEN < UINT16_MAX); |
172 | |
173 | /* |
174 | * Reserved values for the virtual entries (the first must be 0) and EOF. |
175 | * The start/end of the incremental range, see tmpfs_dir_getseq(). |
176 | */ |
177 | #define TMPFS_DIRSEQ_DOT 0 |
178 | #define TMPFS_DIRSEQ_DOTDOT 1 |
179 | #define TMPFS_DIRSEQ_EOF 2 |
180 | |
181 | #define TMPFS_DIRSEQ_START 3 /* inclusive */ |
182 | #define TMPFS_DIRSEQ_END (1U << 30) /* exclusive */ |
183 | |
184 | /* Mark to indicate that the number is not set. */ |
185 | #define TMPFS_DIRSEQ_NONE (1U << 31) |
186 | |
187 | /* Flags: time update requests. */ |
188 | #define TMPFS_UPDATE_ATIME 0x01 |
189 | #define TMPFS_UPDATE_MTIME 0x02 |
190 | #define TMPFS_UPDATE_CTIME 0x04 |
191 | |
192 | /* |
193 | * Bits indicating whiteout use for the directory. |
194 | * We abuse tmpfs_node_t::tn_gen for that. |
195 | */ |
196 | #define TMPFS_WHITEOUT_BIT (1U << 31) |
197 | #define TMPFS_NODE_GEN_MASK (TMPFS_WHITEOUT_BIT - 1) |
198 | |
199 | #define TMPFS_NODE_GEN(node) \ |
200 | ((node)->tn_gen & TMPFS_NODE_GEN_MASK) |
201 | |
202 | /* White-out inode indicator. */ |
203 | #define TMPFS_NODE_WHITEOUT ((tmpfs_node_t *)-1) |
204 | |
205 | /* |
206 | * Bit indicating this node must be reclaimed when holdcount reaches zero. |
207 | * Ored into tmpfs_node_t::tn_holdcount. |
208 | */ |
209 | #define TMPFS_NODE_RECLAIMED (1U << 30) |
210 | |
211 | /* |
212 | * Internal representation of a tmpfs mount point. |
213 | */ |
214 | typedef struct tmpfs_mount { |
215 | /* Limit and number of bytes in use by the file system. */ |
216 | uint64_t tm_mem_limit; |
217 | uint64_t tm_bytes_used; |
218 | kmutex_t tm_acc_lock; |
219 | |
220 | /* Pointer to the root inode. */ |
221 | tmpfs_node_t * tm_root; |
222 | |
223 | /* Maximum number of possible nodes for this file system. */ |
224 | unsigned int tm_nodes_max; |
225 | |
226 | /* Number of nodes currently allocated. */ |
227 | unsigned int tm_nodes_cnt; |
228 | |
229 | /* List of inodes and the lock protecting it. */ |
230 | kmutex_t tm_lock; |
231 | struct tmpfs_node_list tm_nodes; |
232 | } tmpfs_mount_t; |
233 | |
234 | /* |
235 | * This structure maps a file identifier to a tmpfs node. Used by the |
236 | * NFS code. |
237 | */ |
238 | typedef struct tmpfs_fid { |
239 | uint16_t tf_len; |
240 | uint16_t tf_pad; |
241 | uint32_t tf_gen; |
242 | ino_t tf_id; |
243 | } tmpfs_fid_t; |
244 | |
245 | /* |
246 | * Prototypes for tmpfs_subr.c. |
247 | */ |
248 | |
249 | void tmpfs_free_node(tmpfs_mount_t *, tmpfs_node_t *); |
250 | |
251 | int tmpfs_construct_node(vnode_t *, vnode_t **, struct vattr *, |
252 | struct componentname *, char *); |
253 | |
254 | int tmpfs_alloc_dirent(tmpfs_mount_t *, const char *, uint16_t, |
255 | tmpfs_dirent_t **); |
256 | void tmpfs_free_dirent(tmpfs_mount_t *, tmpfs_dirent_t *); |
257 | void tmpfs_dir_attach(tmpfs_node_t *, tmpfs_dirent_t *, tmpfs_node_t *); |
258 | void tmpfs_dir_detach(tmpfs_node_t *, tmpfs_dirent_t *); |
259 | |
260 | tmpfs_dirent_t *tmpfs_dir_lookup(tmpfs_node_t *, struct componentname *); |
261 | tmpfs_dirent_t *tmpfs_dir_cached(tmpfs_node_t *); |
262 | |
263 | uint32_t tmpfs_dir_getseq(tmpfs_node_t *, tmpfs_dirent_t *); |
264 | tmpfs_dirent_t *tmpfs_dir_lookupbyseq(tmpfs_node_t *, off_t); |
265 | int tmpfs_dir_getdents(tmpfs_node_t *, struct uio *, off_t *); |
266 | |
267 | int tmpfs_reg_resize(vnode_t *, off_t); |
268 | |
269 | int tmpfs_chflags(vnode_t *, int, kauth_cred_t, lwp_t *); |
270 | int tmpfs_chmod(vnode_t *, mode_t, kauth_cred_t, lwp_t *); |
271 | int tmpfs_chown(vnode_t *, uid_t, gid_t, kauth_cred_t, lwp_t *); |
272 | int tmpfs_chsize(vnode_t *, u_quad_t, kauth_cred_t, lwp_t *); |
273 | int tmpfs_chtimes(vnode_t *, const struct timespec *, |
274 | const struct timespec *, const struct timespec *, int, |
275 | kauth_cred_t, lwp_t *); |
276 | void tmpfs_update(vnode_t *, unsigned); |
277 | |
278 | /* |
279 | * Prototypes for tmpfs_mem.c. |
280 | */ |
281 | |
282 | void tmpfs_mntmem_init(tmpfs_mount_t *, uint64_t); |
283 | void tmpfs_mntmem_destroy(tmpfs_mount_t *); |
284 | int tmpfs_mntmem_set(tmpfs_mount_t *, uint64_t); |
285 | |
286 | size_t tmpfs_mem_info(bool); |
287 | uint64_t tmpfs_bytes_max(tmpfs_mount_t *); |
288 | size_t tmpfs_pages_avail(tmpfs_mount_t *); |
289 | bool tmpfs_mem_incr(tmpfs_mount_t *, size_t); |
290 | void tmpfs_mem_decr(tmpfs_mount_t *, size_t); |
291 | |
292 | tmpfs_dirent_t *tmpfs_dirent_get(tmpfs_mount_t *); |
293 | void tmpfs_dirent_put(tmpfs_mount_t *, tmpfs_dirent_t *); |
294 | |
295 | tmpfs_node_t * tmpfs_node_get(tmpfs_mount_t *); |
296 | void tmpfs_node_put(tmpfs_mount_t *, tmpfs_node_t *); |
297 | |
298 | char * tmpfs_strname_alloc(tmpfs_mount_t *, size_t); |
299 | void tmpfs_strname_free(tmpfs_mount_t *, char *, size_t); |
300 | bool tmpfs_strname_neqlen(struct componentname *, struct componentname *); |
301 | |
302 | /* |
303 | * Ensures that the node pointed by 'node' is a directory and that its |
304 | * contents are consistent with respect to directories. |
305 | */ |
306 | #define TMPFS_VALIDATE_DIR(node) \ |
307 | KASSERT((node)->tn_vnode == NULL || VOP_ISLOCKED((node)->tn_vnode)); \ |
308 | KASSERT((node)->tn_type == VDIR); \ |
309 | KASSERT((node)->tn_size % sizeof(tmpfs_dirent_t) == 0); |
310 | |
311 | /* |
312 | * Routines to convert VFS structures to tmpfs internal ones. |
313 | */ |
314 | |
315 | static inline tmpfs_mount_t * |
316 | VFS_TO_TMPFS(struct mount *mp) |
317 | { |
318 | tmpfs_mount_t *tmp = mp->mnt_data; |
319 | |
320 | KASSERT(tmp != NULL); |
321 | return tmp; |
322 | } |
323 | |
324 | static inline tmpfs_node_t * |
325 | VP_TO_TMPFS_DIR(vnode_t *vp) |
326 | { |
327 | tmpfs_node_t *node = vp->v_data; |
328 | |
329 | KASSERT(node != NULL); |
330 | TMPFS_VALIDATE_DIR(node); |
331 | return node; |
332 | } |
333 | |
334 | #endif /* defined(_KERNEL) */ |
335 | |
336 | static __inline tmpfs_node_t * |
337 | VP_TO_TMPFS_NODE(vnode_t *vp) |
338 | { |
339 | tmpfs_node_t *node = vp->v_data; |
340 | #ifdef KASSERT |
341 | KASSERT(node != NULL); |
342 | #endif |
343 | return node; |
344 | } |
345 | |
346 | #endif /* _FS_TMPFS_TMPFS_H_ */ |
347 | |