2 * Copyright (c) 2011-2012 The DragonFly Project. All rights reserved.
4 * This code is derived from software contributed to The DragonFly Project
5 * by Matthew Dillon <dillon@dragonflybsd.org>
6 * by Venkatesh Srinivas <vsrinivas@dragonflybsd.org>
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in
16 * the documentation and/or other materials provided with the
18 * 3. Neither the name of The DragonFly Project nor the names of its
19 * contributors may be used to endorse or promote products derived
20 * from this software without specific, prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
23 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
24 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
25 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
26 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
28 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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35 #include <sys/cdefs.h>
36 #include <sys/cdefs.h>
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/types.h>
42 #include <sys/dirent.h>
49 * HAMMER2 offers shared locks, update locks, and exclusive locks on inodes.
51 * Shared locks allow concurrent access to an inode's fields, but exclude
52 * access by concurrent exclusive locks.
54 * Update locks are interesting -- an update lock will be taken after all
55 * shared locks on an inode are released, but once it is in place, shared
56 * locks may proceed. The update field is signalled by a busy flag in the
57 * inode. Only one update lock may be in place at a given time on an inode.
59 * Exclusive locks prevent concurrent access to the inode.
61 * XXX: What do we use each for? How is visibility to the inode controlled?
66 hammer2_inode_lock_ex(hammer2_inode_t *ip)
68 hammer2_chain_lock(ip->hmp, &ip->chain);
72 hammer2_inode_unlock_ex(hammer2_inode_t *ip)
74 hammer2_chain_unlock(ip->hmp, &ip->chain);
78 hammer2_inode_lock_sh(hammer2_inode_t *ip)
80 KKASSERT(ip->chain.refs > 0);
81 lockmgr(&ip->chain.lk, LK_SHARED);
85 hammer2_inode_unlock_sh(hammer2_inode_t *ip)
87 lockmgr(&ip->chain.lk, LK_RELEASE);
93 * The inode must be exclusively locked while soft-busying or soft-unbusying
94 * an inode. Once busied or unbusied the caller can release the lock.
97 hammer2_inode_busy(hammer2_inode_t *ip)
99 if (ip->chain.busy++ == 0)
100 hammer2_chain_ref(ip->hmp, &ip->chain);
104 hammer2_inode_unbusy(hammer2_inode_t *ip)
106 if (--ip->chain.busy == 0)
107 hammer2_chain_drop(ip->hmp, &ip->chain);
115 hammer2_mount_exlock(hammer2_mount_t *hmp)
117 lockmgr(&hmp->vchain.lk, LK_EXCLUSIVE);
121 hammer2_mount_shlock(hammer2_mount_t *hmp)
123 lockmgr(&hmp->vchain.lk, LK_SHARED);
127 hammer2_mount_unlock(hammer2_mount_t *hmp)
129 lockmgr(&hmp->vchain.lk, LK_RELEASE);
133 * Return the directory entry type for an inode
136 hammer2_get_dtype(hammer2_inode_t *ip)
138 switch(ip->ip_data.type) {
139 case HAMMER2_OBJTYPE_UNKNOWN:
141 case HAMMER2_OBJTYPE_DIRECTORY:
143 case HAMMER2_OBJTYPE_REGFILE:
145 case HAMMER2_OBJTYPE_FIFO:
147 case HAMMER2_OBJTYPE_CDEV: /* not supported */
149 case HAMMER2_OBJTYPE_BDEV: /* not supported */
151 case HAMMER2_OBJTYPE_SOFTLINK:
153 case HAMMER2_OBJTYPE_HARDLINK: /* (never directly associated w/vp) */
155 case HAMMER2_OBJTYPE_SOCKET:
157 case HAMMER2_OBJTYPE_WHITEOUT: /* not supported */
166 * Return the directory entry type for an inode
169 hammer2_get_vtype(hammer2_inode_t *ip)
171 switch(ip->ip_data.type) {
172 case HAMMER2_OBJTYPE_UNKNOWN:
174 case HAMMER2_OBJTYPE_DIRECTORY:
176 case HAMMER2_OBJTYPE_REGFILE:
178 case HAMMER2_OBJTYPE_FIFO:
180 case HAMMER2_OBJTYPE_CDEV: /* not supported */
182 case HAMMER2_OBJTYPE_BDEV: /* not supported */
184 case HAMMER2_OBJTYPE_SOFTLINK:
186 case HAMMER2_OBJTYPE_HARDLINK: /* XXX */
188 case HAMMER2_OBJTYPE_SOCKET:
190 case HAMMER2_OBJTYPE_WHITEOUT: /* not supported */
199 hammer2_get_obj_type(enum vtype vtype)
203 return(HAMMER2_OBJTYPE_DIRECTORY);
205 return(HAMMER2_OBJTYPE_REGFILE);
207 return(HAMMER2_OBJTYPE_FIFO);
209 return(HAMMER2_OBJTYPE_SOCKET);
211 return(HAMMER2_OBJTYPE_CDEV);
213 return(HAMMER2_OBJTYPE_BDEV);
215 return(HAMMER2_OBJTYPE_SOFTLINK);
217 return(HAMMER2_OBJTYPE_UNKNOWN);
223 * Convert a hammer2 64-bit time to a timespec.
226 hammer2_time_to_timespec(u_int64_t xtime, struct timespec *ts)
228 ts->tv_sec = (unsigned long)(xtime / 1000000);
229 ts->tv_nsec = (unsigned int)(xtime % 1000000) * 1000L;
233 * Convert a uuid to a unix uid or gid
236 hammer2_to_unix_xid(uuid_t *uuid)
238 return(*(u_int32_t *)&uuid->node[2]);
242 * Borrow HAMMER1's directory hash algorithm #1 with a few modifications.
243 * The filename is split into fields which are hashed separately and then
246 * Differences include: bit 63 must be set to 1 for HAMMER2 (HAMMER1 sets
247 * it to 0), this is because bit63=0 is used for hidden hardlinked inodes.
248 * (This means we do not need to do a 0-check/or-with-0x100000000 either).
250 * Also, the iscsi crc code is used instead of the old crc32 code.
253 hammer2_dirhash(const unsigned char *name, size_t len)
255 const unsigned char *aname = name;
267 for (i = j = 0; i < len; ++i) {
268 if (aname[i] == '.' ||
273 crcx += hammer2_icrc32(aname + j, i - j);
278 crcx += hammer2_icrc32(aname + j, i - j);
281 * The directory hash utilizes the top 32 bits of the 64-bit key.
282 * Bit 63 must be set to 1.
285 key |= (uint64_t)crcx << 32;
288 * l16 - crc of entire filename
290 * This crc reduces degenerate hash collision conditions
292 crcx = hammer2_icrc32(aname, len);
293 crcx = crcx ^ (crcx << 16);
294 key |= crcx & 0xFFFF0000U;
297 * Set bit 15. This allows readdir to strip bit 63 so a positive
298 * 64-bit cookie/offset can always be returned, and still guarantee
299 * that the values 0x0000-0x7FFF are available for artificial entries.