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/*

 * 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       8.9 (Berkeley) 3/30/95

 * $Id: buf.h,v 1.2 2001-09-27 12:02:00 chris Exp $

 */

#ifndef _SYS_BUF_H_

#define _SYS_BUF_H_

#include <sys/queue.h>

#define NOLIST ((struct buf *)0x87654321)

struct buf;

struct iodone_chain {

        long    ic_prev_flags;

        void    (*ic_prev_iodone) __P((struct buf *));

        void    *ic_prev_iodone_chain;

        struct {

                long    ia_long;

                void    *ia_ptr;

        }       ic_args[5];

};

typedef TAILQ_HEAD(buf_queue_head, buf) buf_queue_head, *buf_queue_head_t;

/*

 * 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. */

        TAILQ_ENTRY(buf) b_act;         /* Device driver queue when active. *new* */

        struct  proc *b_proc;           /* Associated proc; NULL if kernel. */

        long    b_flags;                /* B_* flags. */

        unsigned short b_qindex;        /* buffer queue index */

        unsigned char b_usecount;       /* buffer use count */

        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;

        caddr_t b_kvabase;              /* base kva for buffer */

        int     b_kvasize;              /* size of kva for buffer */

        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 *));

                                        /* For nested b_iodone's. */

        struct  iodone_chain *b_iodone_chain;

        struct  vnode *b_vp;            /* Device vnode. */

        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. */

        daddr_t b_pblkno;               /* physical block number */

        caddr_t b_savekva;              /* saved kva for transfer while bouncing */

        void    *b_driver1;             /* for private use by the driver */

        void    *b_driver2;             /* for private use by the driver */

        void    *b_spc;

        union   cluster_info {

                TAILQ_HEAD(cluster_list_head, buf) cluster_head;

                TAILQ_ENTRY(buf) cluster_entry;

        } b_cluster;

        struct  vm_page *b_pages[btoc(MAXPHYS)];

        int             b_npages;

};

/* Device driver compatibility definitions. */

#define b_data   b_un.b_addr            /* b_un.b_addr is not changeable. */

/*

 * These flags are kept in b_flags.

 */

#define B_AGE           0x00000001      /* Move to age queue when I/O done. */

#define B_NEEDCOMMIT    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_MALLOC        0x00010000      /* malloced b_data */

#define B_CLUSTEROK     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_RELBUF        0x00400000      /* Release VMIO buffer. */

#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. */

#define B_PAGING        0x04000000      /* volatile paging I/O -- bypass VMIO */

#define B_ORDERED       0x08000000      /* Must guarantee I/O ordering */

#define B_VMIO          0x20000000      /* VMIO flag */

#define B_CLUSTER       0x40000000      /* pagein op, so swap() can count it */

#define B_BOUNCE        0x80000000      /* bounce buffer flag */

/*

 * number of buffer hash entries

 */

#define BUFHSZ 512

/*

 * buffer hash table calculation, originally by David Greenman

 */

#define BUFHASH(vnp, bn)        \

        (&bufhashtbl[(((unsigned long)(vnp) >> 7)+(int)(bn)) % BUFHSZ])

/*

 * Definitions for the buffer free lists.

 */

#define BUFFER_QUEUES   6       /* number of free buffer queues */

extern LIST_HEAD(bufhashhdr, buf) bufhashtbl[BUFHSZ], invalhash;

extern TAILQ_HEAD(bqueues, buf) bufqueues[BUFFER_QUEUES];

#define QUEUE_NONE      0        /* on no queue */

#define QUEUE_LOCKED    1       /* locked buffers */

#define QUEUE_LRU       2       /* useful buffers */

#define QUEUE_VMIO      3       /* VMIO buffers */

#define QUEUE_AGE       4       /* not-useful buffers */

#define QUEUE_EMPTY     5       /* empty buffer headers*/

/*

 * Zero out the buffer's data area.

 */

#define clrbuf(bp) {                                                    \

        bzero((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

extern int      nbuf;                   /* The number of buffer headers */

extern struct   buf *buf;               /* The buffer headers. */

extern char     *buffers;               /* The buffer contents. */

extern int      bufpages;               /* Number of memory pages in the buffer pool. */

extern struct   buf *swbuf;             /* Swap I/O buffer headers. */

extern int      nswbuf;                 /* Number of swap I/O buffer headers. */

extern TAILQ_HEAD(swqueue, buf) bswlist;

void    bufinit __P((void));

void    bremfree __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     bwrite __P((struct buf *));

void    bdwrite __P((struct buf *));

void    bawrite __P((struct buf *));

int     bowrite __P((struct buf *));

void    brelse __P((struct buf *));

void    bqrelse __P((struct buf *));

int     vfs_bio_awrite __P((struct buf *));

struct buf *     getpbuf __P((void));

struct buf *incore __P((struct vnode *, daddr_t));

struct buf *gbincore __P((struct vnode *, daddr_t));

int     inmem __P((struct vnode *, daddr_t));

struct buf *getblk __P((struct vnode *, daddr_t, int, int, int));

struct buf *geteblk __P((int));

int     allocbuf __P((struct buf *, int));

int     biowait __P((struct buf *));

void    biodone __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 **));

int     cluster_wbuild __P((struct vnode *, long, daddr_t, int));

void    cluster_write __P((struct buf *, u_quad_t));

int     physio __P((void (*)(struct buf *), struct buf *, dev_t,

            int, u_int (*)(struct buf *), struct uio *));

u_int   minphys __P((struct buf *));

void    vfs_bio_clrbuf __P((struct buf *));

void    vfs_busy_pages __P((struct buf *, int clear_modify));

void    vfs_unbusy_pages(struct buf *);

void    vwakeup __P((struct buf *));

void    vmapbuf __P((struct buf *));

void    vunmapbuf __P((struct buf *));

void    relpbuf __P((struct buf *));

void    brelvp __P((struct buf *));

void    bgetvp __P((struct vnode *, struct buf *));

void    pbgetvp __P((struct vnode *, struct buf *));

void    pbrelvp __P((struct buf *));

void    reassignbuf __P((struct buf *, struct vnode *));

struct  buf *trypbuf __P((void));

void    vm_bounce_alloc __P((struct buf *));

void    vm_bounce_free __P((struct buf *));

vm_offset_t     vm_bounce_kva_alloc __P((int));

void    vm_bounce_kva_alloc_free __P((vm_offset_t, int));

#endif /* KERNEL */

#endif /* !_SYS_BUF_H_ */