192 lines
8.3 KiB
C
192 lines
8.3 KiB
C
/* $NetBSD: buf.h,v 1.21 1995/08/12 20:31:53 mycroft Exp $ */
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/*
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* Copyright (c) 1982, 1986, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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* (c) UNIX System Laboratories, Inc.
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* All or some portions of this file are derived from material licensed
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* to the University of California by American Telephone and Telegraph
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* Co. or Unix System Laboratories, Inc. and are reproduced herein with
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* the permission of UNIX System Laboratories, Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)buf.h 8.7 (Berkeley) 1/21/94
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*/
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#ifndef _SYS_BUF_H_
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#define _SYS_BUF_H_
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#include <sys/queue.h>
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#define NOLIST ((struct buf *)0x87654321)
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/*
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* The buffer header describes an I/O operation in the kernel.
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*/
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struct buf {
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LIST_ENTRY(buf) b_hash; /* Hash chain. */
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LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */
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TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */
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struct buf *b_actf, **b_actb; /* Device driver queue when active. */
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struct proc *b_proc; /* Associated proc; NULL if kernel. */
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volatile long b_flags; /* B_* flags. */
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int b_error; /* Errno value. */
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long b_bufsize; /* Allocated buffer size. */
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long b_bcount; /* Valid bytes in buffer. */
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long b_resid; /* Remaining I/O. */
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dev_t b_dev; /* Device associated with buffer. */
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struct {
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caddr_t b_addr; /* Memory, superblocks, indirect etc. */
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} b_un;
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void *b_saveaddr; /* Original b_addr for physio. */
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daddr_t b_lblkno; /* Logical block number. */
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daddr_t b_blkno; /* Underlying physical block number. */
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/* Function to call upon completion. */
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void (*b_iodone) __P((struct buf *));
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struct vnode *b_vp; /* Device vnode. */
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int b_dirtyoff; /* Offset in buffer of dirty region. */
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int b_dirtyend; /* Offset of end of dirty region. */
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struct ucred *b_rcred; /* Read credentials reference. */
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struct ucred *b_wcred; /* Write credentials reference. */
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int b_validoff; /* Offset in buffer of valid region. */
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int b_validend; /* Offset of end of valid region. */
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};
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/*
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* For portability with historic industry practice, the cylinder number has
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* to be maintained in the `b_resid' field.
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*/
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#define b_cylinder b_resid /* Cylinder number for disksort(). */
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/* Device driver compatibility definitions. */
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#define b_active b_bcount /* Driver queue head: drive active. */
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#define b_data b_un.b_addr /* b_un.b_addr is not changeable. */
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#define b_errcnt b_resid /* Retry count while I/O in progress. */
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#define iodone biodone /* Old name for biodone. */
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#define iowait biowait /* Old name for biowait. */
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/*
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* These flags are kept in b_flags.
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*/
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#define B_AGE 0x00000001 /* Move to age queue when I/O done. */
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#define B_APPENDWRITE 0x00000002 /* Append-write in progress. */
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#define B_ASYNC 0x00000004 /* Start I/O, do not wait. */
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#define B_BAD 0x00000008 /* Bad block revectoring in progress. */
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#define B_BUSY 0x00000010 /* I/O in progress. */
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#define B_CACHE 0x00000020 /* Bread found us in the cache. */
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#define B_CALL 0x00000040 /* Call b_iodone from biodone. */
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#define B_DELWRI 0x00000080 /* Delay I/O until buffer reused. */
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#define B_DIRTY 0x00000100 /* Dirty page to be pushed out async. */
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#define B_DONE 0x00000200 /* I/O completed. */
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#define B_EINTR 0x00000400 /* I/O was interrupted */
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#define B_ERROR 0x00000800 /* I/O error occurred. */
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#define B_GATHERED 0x00001000 /* LFS: already in a segment. */
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#define B_INVAL 0x00002000 /* Does not contain valid info. */
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#define B_LOCKED 0x00004000 /* Locked in core (not reusable). */
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#define B_NOCACHE 0x00008000 /* Do not cache block after use. */
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#define B_PAGET 0x00010000 /* Page in/out of page table space. */
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#define B_PGIN 0x00020000 /* Pagein op, so swap() can count it. */
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#define B_PHYS 0x00040000 /* I/O to user memory. */
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#define B_RAW 0x00080000 /* Set by physio for raw transfers. */
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#define B_READ 0x00100000 /* Read buffer. */
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#define B_TAPE 0x00200000 /* Magnetic tape I/O. */
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#define B_UAREA 0x00400000 /* Buffer describes Uarea I/O. */
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#define B_WANTED 0x00800000 /* Process wants this buffer. */
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#define B_WRITE 0x00000000 /* Write buffer (pseudo flag). */
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#define B_WRITEINPROG 0x01000000 /* Write in progress. */
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#define B_XXX 0x02000000 /* Debugging flag. */
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/*
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* This structure describes a clustered I/O. It is stored in the b_saveaddr
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* field of the buffer on which I/O is done. At I/O completion, cluster
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* callback uses the structure to parcel I/O's to individual buffers, and
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* then free's this structure.
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*/
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struct cluster_save {
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long bs_bcount; /* Saved b_bcount. */
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long bs_bufsize; /* Saved b_bufsize. */
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void *bs_saveaddr; /* Saved b_addr. */
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int bs_nchildren; /* Number of associated buffers. */
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struct buf **bs_children; /* List of associated buffers. */
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};
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/*
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* Zero out the buffer's data area.
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*/
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#define clrbuf(bp) { \
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bzero((bp)->b_data, (u_int)(bp)->b_bcount); \
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(bp)->b_resid = 0; \
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}
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/* Flags to low-level allocation routines. */
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#define B_CLRBUF 0x01 /* Request allocated buffer be cleared. */
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#define B_SYNC 0x02 /* Do all allocations synchronously. */
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#ifdef _KERNEL
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int nbuf; /* The number of buffer headers */
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struct buf *buf; /* The buffer headers. */
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char *buffers; /* The buffer contents. */
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int bufpages; /* Number of memory pages in the buffer pool. */
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struct buf *swbuf; /* Swap I/O buffer headers. */
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int nswbuf; /* Number of swap I/O buffer headers. */
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struct buf bswlist; /* Head of swap I/O buffer headers free list. */
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struct buf *bclnlist; /* Head of cleaned page list. */
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__BEGIN_DECLS
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int allocbuf __P((struct buf *, int));
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void bawrite __P((struct buf *));
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void bdwrite __P((struct buf *));
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void biodone __P((struct buf *));
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int biowait __P((struct buf *));
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int bread __P((struct vnode *, daddr_t, int,
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struct ucred *, struct buf **));
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int breada __P((struct vnode *, daddr_t, int, daddr_t, int,
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struct ucred *, struct buf **));
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int breadn __P((struct vnode *, daddr_t, int, daddr_t *, int *, int,
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struct ucred *, struct buf **));
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void brelse __P((struct buf *));
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void bremfree __P((struct buf *));
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void bufinit __P((void));
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int bwrite __P((struct buf *));
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void cluster_callback __P((struct buf *));
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int cluster_read __P((struct vnode *, u_quad_t, daddr_t, long,
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struct ucred *, struct buf **));
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void cluster_write __P((struct buf *, u_quad_t));
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struct buf *getblk __P((struct vnode *, daddr_t, int, int, int));
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struct buf *geteblk __P((int));
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struct buf *getnewbuf __P((int slpflag, int slptimeo));
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struct buf *incore __P((struct vnode *, daddr_t));
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void minphys __P((struct buf *bp));
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int physio __P((void (*strategy)(struct buf *), struct buf *bp, dev_t dev,
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int flags, void (*minphys)(struct buf *), struct uio *uio));
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__END_DECLS
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#endif
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#endif /* !_SYS_BUF_H_ */
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