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Diffstat (limited to 'sys/sys/buf.h')
| -rw-r--r-- | sys/sys/buf.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/sys/sys/buf.h b/sys/sys/buf.h new file mode 100644 index 000000000000..e6c329f239da --- /dev/null +++ b/sys/sys/buf.h @@ -0,0 +1,178 @@ +/* + * Copyright (c) 1982, 1986, 1989, 1993 + * The Regents of the University of California. All rights reserved. + * (c) UNIX System Laboratories, Inc. + * All or some portions of this file are derived from material licensed + * to the University of California by American Telephone and Telegraph + * Co. or Unix System Laboratories, Inc. and are reproduced herein with + * the permission of UNIX System Laboratories, Inc. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)buf.h 8.7 (Berkeley) 1/21/94 + */ + +#ifndef _SYS_BUF_H_ +#define _SYS_BUF_H_ +#include <sys/queue.h> + +#define NOLIST ((struct buf *)0x87654321) + +/* + * The buffer header describes an I/O operation in the kernel. + */ +struct buf { + LIST_ENTRY(buf) b_hash; /* Hash chain. */ + LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */ + TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */ + struct buf *b_actf, **b_actb; /* Device driver queue when active. */ + struct proc *b_proc; /* Associated proc; NULL if kernel. */ + volatile long b_flags; /* B_* flags. */ + int b_error; /* Errno value. */ + long b_bufsize; /* Allocated buffer size. */ + long b_bcount; /* Valid bytes in buffer. */ + long b_resid; /* Remaining I/O. */ + dev_t b_dev; /* Device associated with buffer. */ + struct { + caddr_t b_addr; /* Memory, superblocks, indirect etc. */ + } b_un; + void *b_saveaddr; /* Original b_addr for physio. */ + daddr_t b_lblkno; /* Logical block number. */ + daddr_t b_blkno; /* Underlying physical block number. */ + /* Function to call upon completion. */ + void (*b_iodone) __P((struct buf *)); + struct vnode *b_vp; /* Device vnode. */ + int b_pfcent; /* Center page when swapping cluster. */ + int b_dirtyoff; /* Offset in buffer of dirty region. */ + int b_dirtyend; /* Offset of end of dirty region. */ + struct ucred *b_rcred; /* Read credentials reference. */ + struct ucred *b_wcred; /* Write credentials reference. */ + int b_validoff; /* Offset in buffer of valid region. */ + int b_validend; /* Offset of end of valid region. */ +}; + +/* Device driver compatibility definitions. */ +#define b_active b_bcount /* Driver queue head: drive active. */ +#define b_data b_un.b_addr /* b_un.b_addr is not changeable. */ +#define b_errcnt b_resid /* Retry count while I/O in progress. */ +#define iodone biodone /* Old name for biodone. */ +#define iowait biowait /* Old name for biowait. */ + +/* + * These flags are kept in b_flags. + */ +#define B_AGE 0x00000001 /* Move to age queue when I/O done. */ +#define B_APPENDWRITE 0x00000002 /* Append-write in progress. */ +#define B_ASYNC 0x00000004 /* Start I/O, do not wait. */ +#define B_BAD 0x00000008 /* Bad block revectoring in progress. */ +#define B_BUSY 0x00000010 /* I/O in progress. */ +#define B_CACHE 0x00000020 /* Bread found us in the cache. */ +#define B_CALL 0x00000040 /* Call b_iodone from biodone. */ +#define B_DELWRI 0x00000080 /* Delay I/O until buffer reused. */ +#define B_DIRTY 0x00000100 /* Dirty page to be pushed out async. */ +#define B_DONE 0x00000200 /* I/O completed. */ +#define B_EINTR 0x00000400 /* I/O was interrupted */ +#define B_ERROR 0x00000800 /* I/O error occurred. */ +#define B_GATHERED 0x00001000 /* LFS: already in a segment. */ +#define B_INVAL 0x00002000 /* Does not contain valid info. */ +#define B_LOCKED 0x00004000 /* Locked in core (not reusable). */ +#define B_NOCACHE 0x00008000 /* Do not cache block after use. */ +#define B_PAGET 0x00010000 /* Page in/out of page table space. */ +#define B_PGIN 0x00020000 /* Pagein op, so swap() can count it. */ +#define B_PHYS 0x00040000 /* I/O to user memory. */ +#define B_RAW 0x00080000 /* Set by physio for raw transfers. */ +#define B_READ 0x00100000 /* Read buffer. */ +#define B_TAPE 0x00200000 /* Magnetic tape I/O. */ +#define B_UAREA 0x00400000 /* Buffer describes Uarea I/O. */ +#define B_WANTED 0x00800000 /* Process wants this buffer. */ +#define B_WRITE 0x00000000 /* Write buffer (pseudo flag). */ +#define B_WRITEINPROG 0x01000000 /* Write in progress. */ +#define B_XXX 0x02000000 /* Debugging flag. */ + +/* + * This structure describes a clustered I/O. It is stored in the b_saveaddr + * field of the buffer on which I/O is done. At I/O completion, cluster + * callback uses the structure to parcel I/O's to individual buffers, and + * then free's this structure. + */ +struct cluster_save { + long bs_bcount; /* Saved b_bcount. */ + long bs_bufsize; /* Saved b_bufsize. */ + void *bs_saveaddr; /* Saved b_addr. */ + int bs_nchildren; /* Number of associated buffers. */ + struct buf **bs_children; /* List of associated buffers. */ +}; + +/* + * Zero out the buffer's data area. + */ +#define clrbuf(bp) { \ + blkclr((bp)->b_data, (u_int)(bp)->b_bcount); \ + (bp)->b_resid = 0; \ +} + +/* Flags to low-level allocation routines. */ +#define B_CLRBUF 0x01 /* Request allocated buffer be cleared. */ +#define B_SYNC 0x02 /* Do all allocations synchronously. */ + +#ifdef KERNEL +int nbuf; /* The number of buffer headers */ +struct buf *buf; /* The buffer headers. */ +char *buffers; /* The buffer contents. */ +int bufpages; /* Number of memory pages in the buffer pool. */ +struct buf *swbuf; /* Swap I/O buffer headers. */ +int nswbuf; /* Number of swap I/O buffer headers. */ +struct buf bswlist; /* Head of swap I/O buffer headers free list. */ +struct buf *bclnlist; /* Head of cleaned page list. */ + +__BEGIN_DECLS +int allocbuf __P((struct buf *, int)); +int bawrite __P((struct buf *)); +int bdwrite __P((struct buf *)); +void biodone __P((struct buf *)); +int biowait __P((struct buf *)); +int bread __P((struct vnode *, daddr_t, int, + struct ucred *, struct buf **)); +int breadn __P((struct vnode *, daddr_t, int, daddr_t *, int *, int, + struct ucred *, struct buf **)); +int brelse __P((struct buf *)); +void bufinit __P((void)); +int bwrite __P((struct buf *)); +void cluster_callback __P((struct buf *)); +int cluster_read __P((struct vnode *, u_quad_t, daddr_t, long, + struct ucred *, struct buf **)); +void cluster_write __P((struct buf *, u_quad_t)); +struct buf *getblk __P((struct vnode *, daddr_t, int, int, int)); +struct buf *geteblk __P((int)); +struct buf *getnewbuf __P((int slpflag, int slptimeo)); +struct buf *incore __P((struct vnode *, daddr_t)); +u_int minphys __P((struct buf *bp)); +__END_DECLS +#endif +#endif /* !_SYS_BUF_H_ */ |