1 /* 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * (c) UNIX System Laboratories, Inc. 5 * All or some portions of this file are derived from material licensed 6 * to the University of California by American Telephone and Telegraph 7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 8 * the permission of UNIX System Laboratories, Inc. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#)buf.h 8.9 (Berkeley) 3/30/95 39 * $FreeBSD: src/sys/sys/buf.h,v 1.88.2.10 2003/01/25 19:02:23 dillon Exp $ 40 * $DragonFly: src/sys/sys/buf2.h,v 1.21 2008/01/28 07:19:06 nth Exp $ 41 */ 42 43 #ifndef _SYS_BUF2_H_ 44 #define _SYS_BUF2_H_ 45 46 #ifdef _KERNEL 47 48 #ifndef _SYS_BUF_H_ 49 #include <sys/buf.h> /* crit_*() functions */ 50 #endif 51 #ifndef _SYS_GLOBALDATA_H_ 52 #include <sys/globaldata.h> /* curthread */ 53 #endif 54 #ifndef _SYS_THREAD2_H_ 55 #include <sys/thread2.h> /* crit_*() functions */ 56 #endif 57 #ifndef _SYS_SPINLOCK2_H_ 58 #include <sys/spinlock2.h> /* crit_*() functions */ 59 #endif 60 #ifndef _SYS_MOUNT_H_ 61 #include <sys/mount.h> 62 #endif 63 #ifndef _SYS_VNODE_H_ 64 #include <sys/vnode.h> 65 #endif 66 67 /* 68 * Initialize a lock. 69 */ 70 #define BUF_LOCKINIT(bp) \ 71 lockinit(&(bp)->b_lock, buf_wmesg, 0, 0) 72 73 /* 74 * 75 * Get a lock sleeping non-interruptably until it becomes available. 76 * 77 * XXX lk_wmesg can race, but should not result in any operational issues. 78 */ 79 static __inline int 80 BUF_LOCK(struct buf *bp, int locktype) 81 { 82 bp->b_lock.lk_wmesg = buf_wmesg; 83 return (lockmgr(&(bp)->b_lock, locktype)); 84 } 85 /* 86 * Get a lock sleeping with specified interruptably and timeout. 87 * 88 * XXX lk_timo can race against other entities calling BUF_TIMELOCK, 89 * but will not interfere with entities calling BUF_LOCK since LK_TIMELOCK 90 * will not be set in that case. 91 * 92 * XXX lk_wmesg can race, but should not result in any operational issues. 93 */ 94 static __inline int 95 BUF_TIMELOCK(struct buf *bp, int locktype, char *wmesg, int timo) 96 { 97 bp->b_lock.lk_wmesg = wmesg; 98 bp->b_lock.lk_timo = timo; 99 return (lockmgr(&(bp)->b_lock, locktype | LK_TIMELOCK)); 100 } 101 /* 102 * Release a lock. Only the acquiring process may free the lock unless 103 * it has been handed off to biodone. 104 */ 105 static __inline void 106 BUF_UNLOCK(struct buf *bp) 107 { 108 lockmgr(&(bp)->b_lock, LK_RELEASE); 109 } 110 111 /* 112 * When initiating asynchronous I/O, change ownership of the lock to the 113 * kernel. Once done, the lock may legally released by biodone. The 114 * original owning process can no longer acquire it recursively, but must 115 * wait until the I/O is completed and the lock has been freed by biodone. 116 */ 117 static __inline void 118 BUF_KERNPROC(struct buf *bp) 119 { 120 lockmgr_kernproc(&(bp)->b_lock); 121 } 122 /* 123 * Find out the number of references to a lock. 124 * 125 * The non-blocking version should only be used for assertions in cases 126 * where the buffer is expected to be owned or otherwise data stable. 127 */ 128 static __inline int 129 BUF_REFCNT(struct buf *bp) 130 { 131 return (lockcount(&(bp)->b_lock)); 132 } 133 134 static __inline int 135 BUF_REFCNTNB(struct buf *bp) 136 { 137 return (lockcountnb(&(bp)->b_lock)); 138 } 139 140 /* 141 * Free a buffer lock. 142 */ 143 #define BUF_LOCKFREE(bp) \ 144 if (BUF_REFCNTNB(bp) > 0) \ 145 panic("free locked buf") 146 147 static __inline void 148 bioq_init(struct bio_queue_head *bioq) 149 { 150 TAILQ_INIT(&bioq->queue); 151 bioq->off_unused = 0; 152 bioq->reorder = 0; 153 bioq->transition = NULL; 154 bioq->bio_unused = NULL; 155 } 156 157 static __inline void 158 bioq_insert_tail(struct bio_queue_head *bioq, struct bio *bio) 159 { 160 bioq->transition = NULL; 161 TAILQ_INSERT_TAIL(&bioq->queue, bio, bio_act); 162 } 163 164 static __inline void 165 bioq_remove(struct bio_queue_head *bioq, struct bio *bio) 166 { 167 /* 168 * Adjust read insertion point when removing the bioq. The 169 * bio after the insert point is a write so move backwards 170 * one (NULL will indicate all the reads have cleared). 171 */ 172 if (bio == bioq->transition) 173 bioq->transition = TAILQ_NEXT(bio, bio_act); 174 TAILQ_REMOVE(&bioq->queue, bio, bio_act); 175 } 176 177 static __inline struct bio * 178 bioq_first(struct bio_queue_head *bioq) 179 { 180 return (TAILQ_FIRST(&bioq->queue)); 181 } 182 183 /* 184 * biodeps inlines - used by softupdates and HAMMER. 185 */ 186 static __inline void 187 buf_dep_init(struct buf *bp) 188 { 189 bp->b_ops = NULL; 190 LIST_INIT(&bp->b_dep); 191 } 192 193 /* 194 * Precondition: the buffer has some dependencies. 195 */ 196 static __inline void 197 buf_deallocate(struct buf *bp) 198 { 199 struct bio_ops *ops = bp->b_ops; 200 201 KKASSERT(! LIST_EMPTY(&bp->b_dep)); 202 if (ops) 203 ops->io_deallocate(bp); 204 } 205 206 static __inline int 207 buf_countdeps(struct buf *bp, int n) 208 { 209 struct bio_ops *ops = bp->b_ops; 210 int r; 211 212 if (ops) 213 r = ops->io_countdeps(bp, n); 214 else 215 r = 0; 216 return(r); 217 } 218 219 static __inline void 220 buf_start(struct buf *bp) 221 { 222 struct bio_ops *ops = bp->b_ops; 223 224 if (ops) 225 ops->io_start(bp); 226 } 227 228 static __inline void 229 buf_complete(struct buf *bp) 230 { 231 struct bio_ops *ops = bp->b_ops; 232 233 if (ops) 234 ops->io_complete(bp); 235 } 236 237 static __inline int 238 buf_fsync(struct vnode *vp) 239 { 240 struct bio_ops *ops = vp->v_mount->mnt_bioops; 241 int r; 242 243 if (ops) 244 r = ops->io_fsync(vp); 245 else 246 r = 0; 247 return(r); 248 } 249 250 static __inline void 251 buf_movedeps(struct buf *bp1, struct buf *bp2) 252 { 253 struct bio_ops *ops = bp1->b_ops; 254 255 if (ops) 256 ops->io_movedeps(bp1, bp2); 257 } 258 259 static __inline int 260 buf_checkread(struct buf *bp) 261 { 262 struct bio_ops *ops = bp->b_ops; 263 264 if (ops) 265 return(ops->io_checkread(bp)); 266 return(0); 267 } 268 269 static __inline int 270 buf_checkwrite(struct buf *bp) 271 { 272 struct bio_ops *ops = bp->b_ops; 273 274 if (ops) 275 return(ops->io_checkwrite(bp)); 276 return(0); 277 } 278 279 /* 280 * Chained biodone. The bio callback was made and the callback function 281 * wishes to chain the biodone. If no BIO's are left we call bpdone() 282 * with elseit=TRUE (asynchronous completion). 283 */ 284 static __inline void 285 biodone_chain(struct bio *bio) 286 { 287 if (bio->bio_prev) 288 biodone(bio->bio_prev); 289 else 290 bpdone(bio->bio_buf, 1); 291 } 292 293 #endif /* _KERNEL */ 294 295 #endif /* !_SYS_BUF2_H_ */ 296