54029ac3b790673152be0facebb6884016b908a8
[dragonfly.git] / sys / vfs / hammer / hammer_subs.c
1 /*
2  * Copyright (c) 2007 The DragonFly Project.  All rights reserved.
3  * 
4  * This code is derived from software contributed to The DragonFly Project
5  * by Matthew Dillon <dillon@backplane.com>
6  * 
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in
15  *    the documentation and/or other materials provided with the
16  *    distribution.
17  * 3. Neither the name of The DragonFly Project nor the names of its
18  *    contributors may be used to endorse or promote products derived
19  *    from this software without specific, prior written permission.
20  * 
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  * 
34  * $DragonFly: src/sys/vfs/hammer/hammer_subs.c,v 1.7 2007/11/27 07:48:52 dillon Exp $
35  */
36 /*
37  * HAMMER structural locking
38  */
39
40 #include "hammer.h"
41 #include <sys/dirent.h>
42
43 void
44 hammer_lock_ex(struct hammer_lock *lock)
45 {
46         thread_t td = curthread;
47
48         KKASSERT(lock->refs > 0);
49         crit_enter();
50         if (lock->locktd != td) {
51                 while (lock->locktd != NULL || lock->lockcount) {
52                         lock->wanted = 1;
53                         kprintf("hammer_lock_ex: held by %p\n", lock->locktd);
54                         tsleep(lock, 0, "hmrlck", 0);
55                         kprintf("hammer_lock_ex: try again\n");
56                 }
57                 lock->locktd = td;
58         }
59         ++lock->lockcount;
60         crit_exit();
61 }
62
63 /*
64  * Try to obtain an exclusive lock
65  */
66 int
67 hammer_lock_ex_try(struct hammer_lock *lock)
68 {
69         thread_t td = curthread;
70
71         KKASSERT(lock->refs > 0);
72         crit_enter();
73         if (lock->locktd != td) {
74                 if (lock->locktd != NULL || lock->lockcount)
75                         return(EAGAIN);
76                 lock->locktd = td;
77         }
78         ++lock->lockcount;
79         crit_exit();
80         return(0);
81 }
82
83
84 void
85 hammer_lock_sh(struct hammer_lock *lock)
86 {
87         KKASSERT(lock->refs > 0);
88         crit_enter();
89         while (lock->locktd != NULL) {
90                 if (lock->locktd == curthread) {
91                         ++lock->lockcount;
92                         crit_exit();
93                         return;
94                 }
95                 lock->wanted = 1;
96                 tsleep(lock, 0, "hmrlck", 0);
97         }
98         KKASSERT(lock->lockcount <= 0);
99         --lock->lockcount;
100         crit_exit();
101 }
102
103 void
104 hammer_downgrade(struct hammer_lock *lock)
105 {
106         KKASSERT(lock->lockcount == 1);
107         crit_enter();
108         lock->lockcount = -1;
109         lock->locktd = NULL;
110         if (lock->wanted) {
111                 lock->wanted = 0;
112                 wakeup(lock);
113         }
114         crit_exit();
115         /* XXX memory barrier */
116 }
117
118 void
119 hammer_unlock(struct hammer_lock *lock)
120 {
121         crit_enter();
122         KKASSERT(lock->lockcount != 0);
123         if (lock->lockcount < 0) {
124                 if (++lock->lockcount == 0 && lock->wanted) {
125                         lock->wanted = 0;
126                         wakeup(lock);
127                 }
128         } else {
129                 KKASSERT(lock->locktd == curthread);
130                 if (--lock->lockcount == 0) {
131                         lock->locktd = NULL;
132                         if (lock->wanted) {
133                                 lock->wanted = 0;
134                                 wakeup(lock);
135                         }
136                 }
137
138         }
139         crit_exit();
140 }
141
142 void
143 hammer_ref(struct hammer_lock *lock)
144 {
145         crit_enter();
146         ++lock->refs;
147         crit_exit();
148 }
149
150 void
151 hammer_unref(struct hammer_lock *lock)
152 {
153         crit_enter();
154         KKASSERT(lock->refs > 0);
155         --lock->refs;
156         crit_exit();
157 }
158
159 u_int32_t
160 hammer_to_unix_xid(uuid_t *uuid)
161 {
162         return(*(u_int32_t *)&uuid->node[2]);
163 }
164
165 void
166 hammer_guid_to_uuid(uuid_t *uuid, u_int32_t guid)
167 {
168         bzero(uuid, sizeof(*uuid));
169         *(u_int32_t *)&uuid->node[2] = guid;
170 }
171
172 void
173 hammer_to_timespec(hammer_tid_t tid, struct timespec *ts)
174 {
175         ts->tv_sec = tid / 1000000000;
176         ts->tv_nsec = tid % 1000000000;
177 }
178
179 hammer_tid_t
180 hammer_timespec_to_transid(struct timespec *ts)
181 {
182         hammer_tid_t tid;
183
184         tid = ts->tv_nsec + (unsigned long)ts->tv_sec * 1000000000LL;
185         return(tid);
186 }
187
188
189 /*
190  * Convert a HAMMER filesystem object type to a vnode type
191  */
192 enum vtype
193 hammer_get_vnode_type(u_int8_t obj_type)
194 {
195         switch(obj_type) {
196         case HAMMER_OBJTYPE_DIRECTORY:
197                 return(VDIR);
198         case HAMMER_OBJTYPE_REGFILE:
199                 return(VREG);
200         case HAMMER_OBJTYPE_DBFILE:
201                 return(VDATABASE);
202         case HAMMER_OBJTYPE_FIFO:
203                 return(VFIFO);
204         case HAMMER_OBJTYPE_CDEV:
205                 return(VCHR);
206         case HAMMER_OBJTYPE_BDEV:
207                 return(VBLK);
208         case HAMMER_OBJTYPE_SOFTLINK:
209                 return(VLNK);
210         default:
211                 return(VBAD);
212         }
213         /* not reached */
214 }
215
216 int
217 hammer_get_dtype(u_int8_t obj_type)
218 {
219         switch(obj_type) {
220         case HAMMER_OBJTYPE_DIRECTORY:
221                 return(DT_DIR);
222         case HAMMER_OBJTYPE_REGFILE:
223                 return(DT_REG);
224         case HAMMER_OBJTYPE_DBFILE:
225                 return(DT_DBF);
226         case HAMMER_OBJTYPE_FIFO:
227                 return(DT_FIFO);
228         case HAMMER_OBJTYPE_CDEV:
229                 return(DT_CHR);
230         case HAMMER_OBJTYPE_BDEV:
231                 return(DT_BLK);
232         case HAMMER_OBJTYPE_SOFTLINK:
233                 return(DT_LNK);
234         default:
235                 return(DT_UNKNOWN);
236         }
237         /* not reached */
238 }
239
240 u_int8_t
241 hammer_get_obj_type(enum vtype vtype)
242 {
243         switch(vtype) {
244         case VDIR:
245                 return(HAMMER_OBJTYPE_DIRECTORY);
246         case VREG:
247                 return(HAMMER_OBJTYPE_REGFILE);
248         case VDATABASE:
249                 return(HAMMER_OBJTYPE_DBFILE);
250         case VFIFO:
251                 return(HAMMER_OBJTYPE_FIFO);
252         case VCHR:
253                 return(HAMMER_OBJTYPE_CDEV);
254         case VBLK:
255                 return(HAMMER_OBJTYPE_BDEV);
256         case VLNK:
257                 return(HAMMER_OBJTYPE_SOFTLINK);
258         default:
259                 return(HAMMER_OBJTYPE_UNKNOWN);
260         }
261         /* not reached */
262 }
263
264 /*
265  * Return a namekey hash.   The 64 bit namekey hash consists of a 32 bit
266  * crc in the MSB and 0 in the LSB.  The caller will use the low bits to
267  * generate a unique key and will scan all entries with the same upper
268  * 32 bits when issuing a lookup.
269  *
270  * We strip bit 63 in order to provide a positive key, this way a seek
271  * offset of 0 will represent the base of the directory.
272  */
273 int64_t
274 hammer_directory_namekey(void *name, int len)
275 {
276         int64_t key;
277
278         key = (int64_t)(crc32(name, len) & 0x7FFFFFFF) << 32;
279         return(key);
280 }
281
282 hammer_tid_t
283 hammer_now_tid(void)
284 {
285         struct timespec ts;
286         hammer_tid_t tid;
287
288         getnanotime(&ts);
289         tid = ts.tv_sec * 1000000000LL + ts.tv_nsec;
290         return(tid);
291 }
292