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. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)buf.h 8.9 (Berkeley) 3/30/95 35 * $FreeBSD: src/sys/sys/buf.h,v 1.88.2.10 2003/01/25 19:02:23 dillon Exp $ 36 * $DragonFly: src/sys/sys/buf2.h,v 1.21 2008/01/28 07:19:06 nth Exp $ 37 */ 38 39 #ifndef _SYS_BUF2_H_ 40 #define _SYS_BUF2_H_ 41 42 #ifdef _KERNEL 43 44 #ifndef _SYS_BUF_H_ 45 #include <sys/buf.h> /* crit_*() functions */ 46 #endif 47 #ifndef _SYS_GLOBALDATA_H_ 48 #include <sys/globaldata.h> /* curthread */ 49 #endif 50 #ifndef _SYS_THREAD2_H_ 51 #include <sys/thread2.h> /* crit_*() functions */ 52 #endif 53 #ifndef _SYS_SPINLOCK2_H_ 54 #include <sys/spinlock2.h> /* crit_*() functions */ 55 #endif 56 #ifndef _SYS_MOUNT_H_ 57 #include <sys/mount.h> 58 #endif 59 #ifndef _SYS_VNODE_H_ 60 #include <sys/vnode.h> 61 #endif 62 #ifndef _VM_VM_PAGE_H_ 63 #include <vm/vm_page.h> 64 #endif 65 66 /* 67 * Initialize a lock. 68 */ 69 #define BUF_LOCKINIT(bp) \ 70 lockinit(&(bp)->b_lock, buf_wmesg, 0, 0) 71 72 /* 73 * 74 * Get a lock sleeping non-interruptably until it becomes available. 75 * 76 * XXX lk_wmesg can race, but should not result in any operational issues. 77 */ 78 static __inline int 79 BUF_LOCK(struct buf *bp, int locktype) 80 { 81 bp->b_lock.lk_wmesg = buf_wmesg; 82 return (lockmgr(&(bp)->b_lock, locktype)); 83 } 84 /* 85 * Get a lock sleeping with specified interruptably and timeout. 86 * 87 * XXX lk_timo can race against other entities calling BUF_TIMELOCK, 88 * but will not interfere with entities calling BUF_LOCK since LK_TIMELOCK 89 * will not be set in that case. 90 * 91 * XXX lk_wmesg can race, but should not result in any operational issues. 92 */ 93 static __inline int 94 BUF_TIMELOCK(struct buf *bp, int locktype, char *wmesg, int timo) 95 { 96 bp->b_lock.lk_wmesg = wmesg; 97 bp->b_lock.lk_timo = timo; 98 return (lockmgr(&(bp)->b_lock, locktype | LK_TIMELOCK)); 99 } 100 /* 101 * Release a lock. Only the acquiring process may free the lock unless 102 * it has been handed off to biodone. 103 */ 104 static __inline void 105 BUF_UNLOCK(struct buf *bp) 106 { 107 lockmgr(&(bp)->b_lock, LK_RELEASE); 108 } 109 110 /* 111 * When initiating asynchronous I/O, change ownership of the lock to the 112 * kernel. Once done, the lock may legally released by biodone. The 113 * original owning process can no longer acquire it recursively, but must 114 * wait until the I/O is completed and the lock has been freed by biodone. 115 */ 116 static __inline void 117 BUF_KERNPROC(struct buf *bp) 118 { 119 lockmgr_kernproc(&(bp)->b_lock); 120 } 121 /* 122 * Find out the number of references to a lock. 123 * 124 * The non-blocking version should only be used for assertions in cases 125 * where the buffer is expected to be owned or otherwise data stable. 126 */ 127 static __inline int 128 BUF_REFCNT(struct buf *bp) 129 { 130 return (lockcount(&(bp)->b_lock)); 131 } 132 133 static __inline int 134 BUF_REFCNTNB(struct buf *bp) 135 { 136 return (lockcountnb(&(bp)->b_lock)); 137 } 138 139 /* 140 * Free a buffer lock. 141 */ 142 #define BUF_LOCKFREE(bp) \ 143 if (BUF_REFCNTNB(bp) > 0) \ 144 panic("free locked buf") 145 146 static __inline void 147 bioq_init(struct bio_queue_head *bioq) 148 { 149 TAILQ_INIT(&bioq->queue); 150 bioq->off_unused = 0; 151 bioq->reorder = 0; 152 bioq->transition = NULL; 153 bioq->bio_unused = NULL; 154 } 155 156 static __inline void 157 bioq_insert_tail(struct bio_queue_head *bioq, struct bio *bio) 158 { 159 bioq->transition = NULL; 160 TAILQ_INSERT_TAIL(&bioq->queue, bio, bio_act); 161 } 162 163 static __inline void 164 bioq_remove(struct bio_queue_head *bioq, struct bio *bio) 165 { 166 /* 167 * Adjust read insertion point when removing the bioq. The 168 * bio after the insert point is a write so move backwards 169 * one (NULL will indicate all the reads have cleared). 170 */ 171 if (bio == bioq->transition) 172 bioq->transition = TAILQ_NEXT(bio, bio_act); 173 TAILQ_REMOVE(&bioq->queue, bio, bio_act); 174 } 175 176 static __inline struct bio * 177 bioq_first(struct bio_queue_head *bioq) 178 { 179 return (TAILQ_FIRST(&bioq->queue)); 180 } 181 182 static __inline struct bio * 183 bioq_takefirst(struct bio_queue_head *bioq) 184 { 185 struct bio *bp; 186 187 bp = TAILQ_FIRST(&bioq->queue); 188 if (bp != NULL) 189 bioq_remove(bioq, bp); 190 return (bp); 191 } 192 193 /* 194 * Adjust buffer cache buffer's activity count. This 195 * works similarly to vm_page->act_count. 196 */ 197 static __inline void 198 buf_act_advance(struct buf *bp) 199 { 200 if (bp->b_act_count > ACT_MAX - ACT_ADVANCE) 201 bp->b_act_count = ACT_MAX; 202 else 203 bp->b_act_count += ACT_ADVANCE; 204 } 205 206 static __inline void 207 buf_act_decline(struct buf *bp) 208 { 209 if (bp->b_act_count < ACT_DECLINE) 210 bp->b_act_count = 0; 211 else 212 bp->b_act_count -= ACT_DECLINE; 213 } 214 215 /* 216 * biodeps inlines - used by softupdates and HAMMER. 217 * 218 * All bioops are MPSAFE 219 */ 220 static __inline void 221 buf_dep_init(struct buf *bp) 222 { 223 bp->b_ops = NULL; 224 LIST_INIT(&bp->b_dep); 225 } 226 227 /* 228 * Precondition: the buffer has some dependencies. 229 * 230 * MPSAFE 231 */ 232 static __inline void 233 buf_deallocate(struct buf *bp) 234 { 235 struct bio_ops *ops = bp->b_ops; 236 237 KKASSERT(! LIST_EMPTY(&bp->b_dep)); 238 if (ops) 239 ops->io_deallocate(bp); 240 } 241 242 /* 243 * MPSAFE 244 */ 245 static __inline int 246 buf_countdeps(struct buf *bp, int n) 247 { 248 struct bio_ops *ops = bp->b_ops; 249 int r; 250 251 if (ops) 252 r = ops->io_countdeps(bp, n); 253 else 254 r = 0; 255 return(r); 256 } 257 258 /* 259 * MPSAFE 260 */ 261 static __inline void 262 buf_start(struct buf *bp) 263 { 264 struct bio_ops *ops = bp->b_ops; 265 266 if (ops) 267 ops->io_start(bp); 268 } 269 270 /* 271 * MPSAFE 272 */ 273 static __inline void 274 buf_complete(struct buf *bp) 275 { 276 struct bio_ops *ops = bp->b_ops; 277 278 if (ops) 279 ops->io_complete(bp); 280 } 281 282 /* 283 * MPSAFE 284 */ 285 static __inline int 286 buf_fsync(struct vnode *vp) 287 { 288 struct bio_ops *ops = vp->v_mount->mnt_bioops; 289 int r; 290 291 if (ops) 292 r = ops->io_fsync(vp); 293 else 294 r = 0; 295 return(r); 296 } 297 298 /* 299 * MPSAFE 300 */ 301 static __inline void 302 buf_movedeps(struct buf *bp1, struct buf *bp2) 303 { 304 struct bio_ops *ops = bp1->b_ops; 305 306 if (ops) 307 ops->io_movedeps(bp1, bp2); 308 } 309 310 /* 311 * MPSAFE 312 */ 313 static __inline int 314 buf_checkread(struct buf *bp) 315 { 316 struct bio_ops *ops = bp->b_ops; 317 318 if (ops) 319 return(ops->io_checkread(bp)); 320 return(0); 321 } 322 323 /* 324 * MPSAFE 325 */ 326 static __inline int 327 buf_checkwrite(struct buf *bp) 328 { 329 struct bio_ops *ops = bp->b_ops; 330 331 if (ops) 332 return(ops->io_checkwrite(bp)); 333 return(0); 334 } 335 336 /* 337 * Chained biodone. The bio callback was made and the callback function 338 * wishes to chain the biodone. If no BIO's are left we call bpdone() 339 * with elseit=TRUE (asynchronous completion). 340 * 341 * MPSAFE 342 */ 343 static __inline void 344 biodone_chain(struct bio *bio) 345 { 346 if (bio->bio_prev) 347 biodone(bio->bio_prev); 348 else 349 bpdone(bio->bio_buf, 1); 350 } 351 352 static __inline int 353 bread(struct vnode *vp, off_t loffset, int size, struct buf **bpp) 354 { 355 *bpp = NULL; 356 return(breadnx(vp, loffset, size, NULL, NULL, 0, bpp)); 357 } 358 359 360 static __inline int 361 breadn(struct vnode *vp, off_t loffset, int size, off_t *raoffset, 362 int *rabsize, int cnt, struct buf **bpp) 363 { 364 *bpp = NULL; 365 return(breadnx(vp, loffset, size, raoffset, rabsize, cnt, bpp)); 366 } 367 368 static __inline int 369 cluster_read(struct vnode *vp, off_t filesize, off_t loffset, 370 int blksize, size_t minreq, size_t maxreq, struct buf **bpp) 371 { 372 *bpp = NULL; 373 return(cluster_readx(vp, filesize, loffset, blksize, minreq, 374 maxreq, bpp)); 375 } 376 377 #endif /* _KERNEL */ 378 379 #endif /* !_SYS_BUF2_H_ */ 380