buf.h revision 285402
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 * 4. 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: stable/10/sys/sys/buf.h 285402 2015-07-11 19:11:40Z kib $ 36 */ 37 38#ifndef _SYS_BUF_H_ 39#define _SYS_BUF_H_ 40 41#include <sys/bufobj.h> 42#include <sys/queue.h> 43#include <sys/lock.h> 44#include <sys/lockmgr.h> 45 46struct bio; 47struct buf; 48struct bufobj; 49struct mount; 50struct vnode; 51struct uio; 52 53/* 54 * To avoid including <ufs/ffs/softdep.h> 55 */ 56LIST_HEAD(workhead, worklist); 57/* 58 * These are currently used only by the soft dependency code, hence 59 * are stored once in a global variable. If other subsystems wanted 60 * to use these hooks, a pointer to a set of bio_ops could be added 61 * to each buffer. 62 */ 63extern struct bio_ops { 64 void (*io_start)(struct buf *); 65 void (*io_complete)(struct buf *); 66 void (*io_deallocate)(struct buf *); 67 int (*io_countdeps)(struct buf *, int); 68} bioops; 69 70struct vm_object; 71 72typedef unsigned char b_xflags_t; 73 74/* 75 * The buffer header describes an I/O operation in the kernel. 76 * 77 * NOTES: 78 * b_bufsize, b_bcount. b_bufsize is the allocation size of the 79 * buffer, either DEV_BSIZE or PAGE_SIZE aligned. b_bcount is the 80 * originally requested buffer size and can serve as a bounds check 81 * against EOF. For most, but not all uses, b_bcount == b_bufsize. 82 * 83 * b_dirtyoff, b_dirtyend. Buffers support piecemeal, unaligned 84 * ranges of dirty data that need to be written to backing store. 85 * The range is typically clipped at b_bcount ( not b_bufsize ). 86 * 87 * b_resid. Number of bytes remaining in I/O. After an I/O operation 88 * completes, b_resid is usually 0 indicating 100% success. 89 * 90 * All fields are protected by the buffer lock except those marked: 91 * V - Protected by owning bufobj lock 92 * Q - Protected by the buf queue lock 93 * D - Protected by an dependency implementation specific lock 94 */ 95struct buf { 96 struct bufobj *b_bufobj; 97 long b_bcount; 98 void *b_caller1; 99 caddr_t b_data; 100 int b_error; 101 uint8_t b_iocmd; 102 uint8_t b_ioflags; 103 off_t b_iooffset; 104 long b_resid; 105 void (*b_iodone)(struct buf *); 106 daddr_t b_blkno; /* Underlying physical block number. */ 107 off_t b_offset; /* Offset into file. */ 108 TAILQ_ENTRY(buf) b_bobufs; /* (V) Buffer's associated vnode. */ 109 uint32_t b_vflags; /* (V) BV_* flags */ 110 TAILQ_ENTRY(buf) b_freelist; /* (Q) Free list position inactive. */ 111 unsigned short b_qindex; /* (Q) buffer queue index */ 112 uint32_t b_flags; /* B_* flags. */ 113 b_xflags_t b_xflags; /* extra flags */ 114 struct lock b_lock; /* Buffer lock */ 115 long b_bufsize; /* Allocated buffer size. */ 116 long b_runningbufspace; /* when I/O is running, pipelining */ 117 caddr_t b_kvabase; /* base kva for buffer */ 118 caddr_t b_kvaalloc; /* allocated kva for B_KVAALLOC */ 119 int b_kvasize; /* size of kva for buffer */ 120 daddr_t b_lblkno; /* Logical block number. */ 121 struct vnode *b_vp; /* Device vnode. */ 122 int b_dirtyoff; /* Offset in buffer of dirty region. */ 123 int b_dirtyend; /* Offset of end of dirty region. */ 124 struct ucred *b_rcred; /* Read credentials reference. */ 125 struct ucred *b_wcred; /* Write credentials reference. */ 126 void *b_saveaddr; /* Original b_addr for physio. */ 127 union pager_info { 128 int pg_reqpage; 129 } b_pager; 130 union cluster_info { 131 TAILQ_HEAD(cluster_list_head, buf) cluster_head; 132 TAILQ_ENTRY(buf) cluster_entry; 133 } b_cluster; 134 struct vm_page *b_pages[btoc(MAXPHYS)]; 135 int b_npages; 136 struct workhead b_dep; /* (D) List of filesystem dependencies. */ 137 void *b_fsprivate1; 138 void *b_fsprivate2; 139 void *b_fsprivate3; 140 int b_pin_count; 141}; 142 143#define b_object b_bufobj->bo_object 144 145/* 146 * These flags are kept in b_flags. 147 * 148 * Notes: 149 * 150 * B_ASYNC VOP calls on bp's are usually async whether or not 151 * B_ASYNC is set, but some subsystems, such as NFS, like 152 * to know what is best for the caller so they can 153 * optimize the I/O. 154 * 155 * B_PAGING Indicates that bp is being used by the paging system or 156 * some paging system and that the bp is not linked into 157 * the b_vp's clean/dirty linked lists or ref counts. 158 * Buffer vp reassignments are illegal in this case. 159 * 160 * B_CACHE This may only be set if the buffer is entirely valid. 161 * The situation where B_DELWRI is set and B_CACHE is 162 * clear MUST be committed to disk by getblk() so 163 * B_DELWRI can also be cleared. See the comments for 164 * getblk() in kern/vfs_bio.c. If B_CACHE is clear, 165 * the caller is expected to clear BIO_ERROR and B_INVAL, 166 * set BIO_READ, and initiate an I/O. 167 * 168 * The 'entire buffer' is defined to be the range from 169 * 0 through b_bcount. 170 * 171 * B_MALLOC Request that the buffer be allocated from the malloc 172 * pool, DEV_BSIZE aligned instead of PAGE_SIZE aligned. 173 * 174 * B_CLUSTEROK This flag is typically set for B_DELWRI buffers 175 * by filesystems that allow clustering when the buffer 176 * is fully dirty and indicates that it may be clustered 177 * with other adjacent dirty buffers. Note the clustering 178 * may not be used with the stage 1 data write under NFS 179 * but may be used for the commit rpc portion. 180 * 181 * B_VMIO Indicates that the buffer is tied into an VM object. 182 * The buffer's data is always PAGE_SIZE aligned even 183 * if b_bufsize and b_bcount are not. ( b_bufsize is 184 * always at least DEV_BSIZE aligned, though ). 185 * 186 * B_DIRECT Hint that we should attempt to completely free 187 * the pages underlying the buffer. B_DIRECT is 188 * sticky until the buffer is released and typically 189 * only has an effect when B_RELBUF is also set. 190 * 191 */ 192 193#define B_AGE 0x00000001 /* Move to age queue when I/O done. */ 194#define B_NEEDCOMMIT 0x00000002 /* Append-write in progress. */ 195#define B_ASYNC 0x00000004 /* Start I/O, do not wait. */ 196#define B_DIRECT 0x00000008 /* direct I/O flag (pls free vmio) */ 197#define B_DEFERRED 0x00000010 /* Skipped over for cleaning */ 198#define B_CACHE 0x00000020 /* Bread found us in the cache. */ 199#define B_VALIDSUSPWRT 0x00000040 /* Valid write during suspension. */ 200#define B_DELWRI 0x00000080 /* Delay I/O until buffer reused. */ 201#define B_PERSISTENT 0x00000100 /* Perm. ref'ed while EXT2FS mounted. */ 202#define B_DONE 0x00000200 /* I/O completed. */ 203#define B_EINTR 0x00000400 /* I/O was interrupted */ 204#define B_UNMAPPED 0x00000800 /* KVA is not mapped. */ 205#define B_KVAALLOC 0x00001000 /* But allocated. */ 206#define B_INVAL 0x00002000 /* Does not contain valid info. */ 207#define B_BARRIER 0x00004000 /* Write this and all preceeding first. */ 208#define B_NOCACHE 0x00008000 /* Do not cache block after use. */ 209#define B_MALLOC 0x00010000 /* malloced b_data */ 210#define B_CLUSTEROK 0x00020000 /* Pagein op, so swap() can count it. */ 211#define B_000400000 0x00040000 /* Available flag. */ 212#define B_000800000 0x00080000 /* Available flag. */ 213#define B_00100000 0x00100000 /* Available flag. */ 214#define B_DIRTY 0x00200000 /* Needs writing later (in EXT2FS). */ 215#define B_RELBUF 0x00400000 /* Release VMIO buffer. */ 216#define B_00800000 0x00800000 /* Available flag. */ 217#define B_NOCOPY 0x01000000 /* Don't copy-on-write this buf. */ 218#define B_INFREECNT 0x02000000 /* buf is counted in numfreebufs */ 219#define B_PAGING 0x04000000 /* volatile paging I/O -- bypass VMIO */ 220#define B_MANAGED 0x08000000 /* Managed by FS. */ 221#define B_RAM 0x10000000 /* Read ahead mark (flag) */ 222#define B_VMIO 0x20000000 /* VMIO flag */ 223#define B_CLUSTER 0x40000000 /* pagein op, so swap() can count it */ 224#define B_REMFREE 0x80000000 /* Delayed bremfree */ 225 226#define PRINT_BUF_FLAGS "\20\40remfree\37cluster\36vmio\35ram\34managed" \ 227 "\33paging\32infreecnt\31nocopy\30b23\27relbuf\26dirty\25b20" \ 228 "\24b19\23b18\22clusterok\21malloc\20nocache\17b14\16inval" \ 229 "\15kvaalloc\14unmapped\13eintr\12done\11persist\10delwri" \ 230 "\7validsuspwrt\6cache\5deferred\4direct\3async\2needcommit\1age" 231 232/* 233 * These flags are kept in b_xflags. 234 */ 235#define BX_VNDIRTY 0x00000001 /* On vnode dirty list */ 236#define BX_VNCLEAN 0x00000002 /* On vnode clean list */ 237#define BX_BKGRDWRITE 0x00000010 /* Do writes in background */ 238#define BX_BKGRDMARKER 0x00000020 /* Mark buffer for splay tree */ 239#define BX_ALTDATA 0x00000040 /* Holds extended data */ 240 241#define PRINT_BUF_XFLAGS "\20\7altdata\6bkgrdmarker\5bkgrdwrite\2clean\1dirty" 242 243#define NOOFFSET (-1LL) /* No buffer offset calculated yet */ 244 245/* 246 * These flags are kept in b_vflags. 247 */ 248#define BV_SCANNED 0x00000001 /* VOP_FSYNC funcs mark written bufs */ 249#define BV_BKGRDINPROG 0x00000002 /* Background write in progress */ 250#define BV_BKGRDWAIT 0x00000004 /* Background write waiting */ 251#define BV_BKGRDERR 0x00000008 /* Error from background write */ 252 253#define PRINT_BUF_VFLAGS "\20\4bkgrderr\3bkgrdwait\2bkgrdinprog\1scanned" 254 255#ifdef _KERNEL 256/* 257 * Buffer locking 258 */ 259extern const char *buf_wmesg; /* Default buffer lock message */ 260#define BUF_WMESG "bufwait" 261#include <sys/proc.h> /* XXX for curthread */ 262#include <sys/mutex.h> 263 264/* 265 * Initialize a lock. 266 */ 267#define BUF_LOCKINIT(bp) \ 268 lockinit(&(bp)->b_lock, PRIBIO + 4, buf_wmesg, 0, 0) 269/* 270 * 271 * Get a lock sleeping non-interruptably until it becomes available. 272 */ 273#define BUF_LOCK(bp, locktype, interlock) \ 274 _lockmgr_args_rw(&(bp)->b_lock, (locktype), (interlock), \ 275 LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, \ 276 LOCK_FILE, LOCK_LINE) 277 278/* 279 * Get a lock sleeping with specified interruptably and timeout. 280 */ 281#define BUF_TIMELOCK(bp, locktype, interlock, wmesg, catch, timo) \ 282 _lockmgr_args_rw(&(bp)->b_lock, (locktype) | LK_TIMELOCK, \ 283 (interlock), (wmesg), (PRIBIO + 4) | (catch), (timo), \ 284 LOCK_FILE, LOCK_LINE) 285 286/* 287 * Release a lock. Only the acquiring process may free the lock unless 288 * it has been handed off to biodone. 289 */ 290#define BUF_UNLOCK(bp) do { \ 291 KASSERT(((bp)->b_flags & B_REMFREE) == 0, \ 292 ("BUF_UNLOCK %p while B_REMFREE is still set.", (bp))); \ 293 \ 294 (void)_lockmgr_args(&(bp)->b_lock, LK_RELEASE, NULL, \ 295 LK_WMESG_DEFAULT, LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, \ 296 LOCK_FILE, LOCK_LINE); \ 297} while (0) 298 299/* 300 * Check if a buffer lock is recursed. 301 */ 302#define BUF_LOCKRECURSED(bp) \ 303 lockmgr_recursed(&(bp)->b_lock) 304 305/* 306 * Check if a buffer lock is currently held. 307 */ 308#define BUF_ISLOCKED(bp) \ 309 lockstatus(&(bp)->b_lock) 310/* 311 * Free a buffer lock. 312 */ 313#define BUF_LOCKFREE(bp) \ 314 lockdestroy(&(bp)->b_lock) 315 316/* 317 * Print informations on a buffer lock. 318 */ 319#define BUF_LOCKPRINTINFO(bp) \ 320 lockmgr_printinfo(&(bp)->b_lock) 321 322/* 323 * Buffer lock assertions. 324 */ 325#if defined(INVARIANTS) && defined(INVARIANT_SUPPORT) 326#define BUF_ASSERT_LOCKED(bp) \ 327 _lockmgr_assert(&(bp)->b_lock, KA_LOCKED, LOCK_FILE, LOCK_LINE) 328#define BUF_ASSERT_SLOCKED(bp) \ 329 _lockmgr_assert(&(bp)->b_lock, KA_SLOCKED, LOCK_FILE, LOCK_LINE) 330#define BUF_ASSERT_XLOCKED(bp) \ 331 _lockmgr_assert(&(bp)->b_lock, KA_XLOCKED, LOCK_FILE, LOCK_LINE) 332#define BUF_ASSERT_UNLOCKED(bp) \ 333 _lockmgr_assert(&(bp)->b_lock, KA_UNLOCKED, LOCK_FILE, LOCK_LINE) 334#define BUF_ASSERT_HELD(bp) 335#define BUF_ASSERT_UNHELD(bp) 336#else 337#define BUF_ASSERT_LOCKED(bp) 338#define BUF_ASSERT_SLOCKED(bp) 339#define BUF_ASSERT_XLOCKED(bp) 340#define BUF_ASSERT_UNLOCKED(bp) 341#define BUF_ASSERT_HELD(bp) 342#define BUF_ASSERT_UNHELD(bp) 343#endif 344 345#ifdef _SYS_PROC_H_ /* Avoid #include <sys/proc.h> pollution */ 346/* 347 * When initiating asynchronous I/O, change ownership of the lock to the 348 * kernel. Once done, the lock may legally released by biodone. The 349 * original owning process can no longer acquire it recursively, but must 350 * wait until the I/O is completed and the lock has been freed by biodone. 351 */ 352#define BUF_KERNPROC(bp) \ 353 _lockmgr_disown(&(bp)->b_lock, LOCK_FILE, LOCK_LINE) 354#endif 355 356/* 357 * Find out if the lock has waiters or not. 358 */ 359#define BUF_LOCKWAITERS(bp) \ 360 lockmgr_waiters(&(bp)->b_lock) 361 362#endif /* _KERNEL */ 363 364struct buf_queue_head { 365 TAILQ_HEAD(buf_queue, buf) queue; 366 daddr_t last_pblkno; 367 struct buf *insert_point; 368 struct buf *switch_point; 369}; 370 371/* 372 * This structure describes a clustered I/O. It is stored in the b_saveaddr 373 * field of the buffer on which I/O is done. At I/O completion, cluster 374 * callback uses the structure to parcel I/O's to individual buffers, and 375 * then free's this structure. 376 */ 377struct cluster_save { 378 long bs_bcount; /* Saved b_bcount. */ 379 long bs_bufsize; /* Saved b_bufsize. */ 380 void *bs_saveaddr; /* Saved b_addr. */ 381 int bs_nchildren; /* Number of associated buffers. */ 382 struct buf **bs_children; /* List of associated buffers. */ 383}; 384 385#ifdef _KERNEL 386 387static __inline int 388bwrite(struct buf *bp) 389{ 390 391 KASSERT(bp->b_bufobj != NULL, ("bwrite: no bufobj bp=%p", bp)); 392 KASSERT(bp->b_bufobj->bo_ops != NULL, ("bwrite: no bo_ops bp=%p", bp)); 393 KASSERT(bp->b_bufobj->bo_ops->bop_write != NULL, 394 ("bwrite: no bop_write bp=%p", bp)); 395 return (BO_WRITE(bp->b_bufobj, bp)); 396} 397 398static __inline void 399bstrategy(struct buf *bp) 400{ 401 402 KASSERT(bp->b_bufobj != NULL, ("bstrategy: no bufobj bp=%p", bp)); 403 KASSERT(bp->b_bufobj->bo_ops != NULL, 404 ("bstrategy: no bo_ops bp=%p", bp)); 405 KASSERT(bp->b_bufobj->bo_ops->bop_strategy != NULL, 406 ("bstrategy: no bop_strategy bp=%p", bp)); 407 BO_STRATEGY(bp->b_bufobj, bp); 408} 409 410static __inline void 411buf_start(struct buf *bp) 412{ 413 if (bioops.io_start) 414 (*bioops.io_start)(bp); 415} 416 417static __inline void 418buf_complete(struct buf *bp) 419{ 420 if (bioops.io_complete) 421 (*bioops.io_complete)(bp); 422} 423 424static __inline void 425buf_deallocate(struct buf *bp) 426{ 427 if (bioops.io_deallocate) 428 (*bioops.io_deallocate)(bp); 429} 430 431static __inline int 432buf_countdeps(struct buf *bp, int i) 433{ 434 if (bioops.io_countdeps) 435 return ((*bioops.io_countdeps)(bp, i)); 436 else 437 return (0); 438} 439 440#endif /* _KERNEL */ 441 442/* 443 * Zero out the buffer's data area. 444 */ 445#define clrbuf(bp) { \ 446 bzero((bp)->b_data, (u_int)(bp)->b_bcount); \ 447 (bp)->b_resid = 0; \ 448} 449 450/* 451 * Flags for getblk's last parameter. 452 */ 453#define GB_LOCK_NOWAIT 0x0001 /* Fail if we block on a buf lock. */ 454#define GB_NOCREAT 0x0002 /* Don't create a buf if not found. */ 455#define GB_NOWAIT_BD 0x0004 /* Do not wait for bufdaemon. */ 456#define GB_UNMAPPED 0x0008 /* Do not mmap buffer pages. */ 457#define GB_KVAALLOC 0x0010 /* But allocate KVA. */ 458 459#ifdef _KERNEL 460extern int nbuf; /* The number of buffer headers */ 461extern long maxswzone; /* Max KVA for swap structures */ 462extern long maxbcache; /* Max KVA for buffer cache */ 463extern long runningbufspace; 464extern long hibufspace; 465extern int dirtybufthresh; 466extern int bdwriteskip; 467extern int dirtybufferflushes; 468extern int altbufferflushes; 469extern struct buf *buf; /* The buffer headers. */ 470extern struct buf *swbuf; /* Swap I/O buffer headers. */ 471extern int nswbuf; /* Number of swap I/O buffer headers. */ 472extern int cluster_pbuf_freecnt; /* Number of pbufs for clusters */ 473extern int vnode_pbuf_freecnt; /* Number of pbufs for vnode pager */ 474extern caddr_t unmapped_buf; 475 476void runningbufwakeup(struct buf *); 477void waitrunningbufspace(void); 478caddr_t kern_vfs_bio_buffer_alloc(caddr_t v, long physmem_est); 479void bufinit(void); 480void bdata2bio(struct buf *bp, struct bio *bip); 481void bwillwrite(void); 482int buf_dirty_count_severe(void); 483void bremfree(struct buf *); 484void bremfreef(struct buf *); /* XXX Force bremfree, only for nfs. */ 485#define bread(vp, blkno, size, cred, bpp) \ 486 breadn_flags(vp, blkno, size, NULL, NULL, 0, cred, 0, bpp) 487#define bread_gb(vp, blkno, size, cred, gbflags, bpp) \ 488 breadn_flags(vp, blkno, size, NULL, NULL, 0, cred, \ 489 gbflags, bpp) 490#define breadn(vp, blkno, size, rablkno, rabsize, cnt, cred, bpp) \ 491 breadn_flags(vp, blkno, size, rablkno, rabsize, cnt, cred, 0, bpp) 492int breadn_flags(struct vnode *, daddr_t, int, daddr_t *, int *, int, 493 struct ucred *, int, struct buf **); 494void breada(struct vnode *, daddr_t *, int *, int, struct ucred *); 495void bdwrite(struct buf *); 496void bawrite(struct buf *); 497void babarrierwrite(struct buf *); 498int bbarrierwrite(struct buf *); 499void bdirty(struct buf *); 500void bundirty(struct buf *); 501void bufstrategy(struct bufobj *, struct buf *); 502void brelse(struct buf *); 503void bqrelse(struct buf *); 504int vfs_bio_awrite(struct buf *); 505void vfs_drain_busy_pages(struct buf *bp); 506struct buf * getpbuf(int *); 507struct buf *incore(struct bufobj *, daddr_t); 508struct buf *gbincore(struct bufobj *, daddr_t); 509struct buf *getblk(struct vnode *, daddr_t, int, int, int, int); 510struct buf *geteblk(int, int); 511int bufwait(struct buf *); 512int bufwrite(struct buf *); 513void bufdone(struct buf *); 514void bufdone_finish(struct buf *); 515void bd_speedup(void); 516 517int cluster_read(struct vnode *, u_quad_t, daddr_t, long, 518 struct ucred *, long, int, int, struct buf **); 519int cluster_wbuild(struct vnode *, long, daddr_t, int, int); 520void cluster_write(struct vnode *, struct buf *, u_quad_t, int, int); 521void vfs_bio_bzero_buf(struct buf *bp, int base, int size); 522void vfs_bio_set_valid(struct buf *, int base, int size); 523void vfs_bio_clrbuf(struct buf *); 524void vfs_busy_pages(struct buf *, int clear_modify); 525void vfs_unbusy_pages(struct buf *); 526int vmapbuf(struct buf *, int); 527void vunmapbuf(struct buf *); 528void relpbuf(struct buf *, int *); 529void brelvp(struct buf *); 530void bgetvp(struct vnode *, struct buf *); 531void pbgetbo(struct bufobj *bo, struct buf *bp); 532void pbgetvp(struct vnode *, struct buf *); 533void pbrelbo(struct buf *); 534void pbrelvp(struct buf *); 535int allocbuf(struct buf *bp, int size); 536void reassignbuf(struct buf *); 537struct buf *trypbuf(int *); 538void bwait(struct buf *, u_char, const char *); 539void bdone(struct buf *); 540void bpin(struct buf *); 541void bunpin(struct buf *); 542void bunpin_wait(struct buf *); 543 544#endif /* _KERNEL */ 545 546#endif /* !_SYS_BUF_H_ */ 547