/*
* 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 1.62 1999/01/21 08:29:08 dillon Exp $
*/
#ifndef _SYS_BUF_H_
#define _SYS_BUF_H_
#include <sys/queue.h>
struct buf;
struct mount;
struct vnode;
/*
* To avoid including <ufs/ffs/softdep.h>
*/
LIST_HEAD(workhead, worklist);
/*
* These are currently used only by the soft dependency code, hence
* are stored once in a global variable. If other subsystems wanted
* to use these hooks, a pointer to a set of bio_ops could be added
* to each buffer.
*/
extern struct bio_ops {
void (*io_start) __P((struct buf *));
void (*io_complete) __P((struct buf *));
void (*io_deallocate) __P((struct buf *));
int (*io_fsync) __P((struct vnode *));
int (*io_sync) __P((struct mount *));
} bioops;
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];
};
/*
* The buffer header describes an I/O operation in the kernel.
*/
struct buf {
LIST_ENTRY(buf) b_hash; /* Hash chain. */
TAILQ_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 */
unsigned char b_xflags; /* extra 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. */
caddr_t b_data; /* Memory, superblocks, indirect etc. */
caddr_t b_kvabase; /* base kva for buffer */
int b_kvasize; /* size of kva for buffer */
daddr_t b_lblkno; /* Logical block number. */
daddr_t b_blkno; /* Underlying physical block number. */
off_t b_offset; /* Offset into file */
/* 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 */
void *b_saveaddr; /* Original b_addr for physio. */
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 */
union pager_info {
void *pg_spc;
int pg_reqpage;
} b_pager;
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;
struct workhead b_dep; /* List of filesystem dependencies. */
};
#define b_spc b_pager.pg_spc
/*
* These flags are kept in b_flags.
*
* Notes:
*
* B_ASYNC VOP calls on bp's are usually async whether or not
* B_ASYNC is set, but some subsystems, such as NFS, like
* to know what is best for the caller so they can
* optimize the I/O.
*
* B_PAGING Indicates that bp is being used by the paging system or
* some paging system and that the bp is not linked into
* the b_vp's clean/dirty linked lists or ref counts.
* Buffer vp reassignments are illegal in this case.
*
* B_CACHE This may only be set if the buffer is entirely valid.
* The situation where B_DELWRI is set and B_CACHE gets
* cleared MUST be committed to disk so B_DELWRI can
* also be cleared.
*/
#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_FREEBUF 0x00000100 /* Instruct driver: free blocks */
#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_AVAIL2 0x00001000 /* Available flag */
#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_DIRTY 0x00200000 /* Needs writing later. */
#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_RAM 0x10000000 /* Read ahead mark (flag) */
#define B_VMIO 0x20000000 /* VMIO flag */
#define B_CLUSTER 0x40000000 /* pagein op, so swap() can count it */
#define B_AVAIL1 0x80000000 /* Available flag */
#define PRINT_BUF_FLAGS "\20\40avail1\37cluster\36vmio\35ram\34ordered" \
"\33paging\32xxx\31writeinprog\30wanted\27relbuf\26dirty" \
"\25read\24raw\23phys\22clusterok\21malloc\20nocache" \
"\17locked\16inval\15avail2\14error\13eintr\12done\11freebuf" \
"\10delwri\7call\6cache\5busy\4bad\3async\2needcommit\1age"
/*
* These flags are kept in b_xflags.
*/
#define B_VNDIRTY 0x01 /* On vnode dirty list */
#define B_VNCLEAN 0x02 /* On vnode clean list */
#define NOOFFSET (-1LL) /* No buffer offset calculated yet */
struct buf_queue_head {
TAILQ_HEAD(buf_queue, buf) queue;
daddr_t last_pblkno;
struct buf *insert_point;
struct buf *switch_point;
};
/*
* 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. */
};
static __inline void bufq_init __P((struct buf_queue_head *head));
static __inline void bufq_insert_tail __P((struct buf_queue_head *head,
struct buf *bp));
static __inline void bufq_remove __P((struct buf_queue_head *head,
struct buf *bp));
static __inline struct buf *bufq_first __P((struct buf_queue_head *head));
static __inline void
bufq_init(struct buf_queue_head *head)
{
TAILQ_INIT(&head->queue);
head->last_pblkno = 0;
head->insert_point = NULL;
head->switch_point = NULL;
}
static __inline void
bufq_insert_tail(struct buf_queue_head *head, struct buf *bp)
{
if ((bp->b_flags & B_ORDERED) != 0) {
head->insert_point = bp;
head->switch_point = NULL;
}
TAILQ_INSERT_TAIL(&head->queue, bp, b_act);
}
static __inline void
bufq_remove(struct buf_queue_head *head, struct buf *bp)
{
if (bp == head->switch_point)
head->switch_point = TAILQ_NEXT(bp, b_act);
if (bp == head->insert_point) {
head->insert_point = TAILQ_PREV(bp, buf_queue, b_act);
if (head->insert_point == NULL)
head->last_pblkno = 0;
} else if (bp == TAILQ_FIRST(&head->queue))
head->last_pblkno = bp->b_pblkno;
TAILQ_REMOVE(&head->queue, bp, b_act);
if (TAILQ_FIRST(&head->queue) == head->switch_point)
head->switch_point = NULL;
}
static __inline struct buf *
bufq_first(struct buf_queue_head *head)
{
return (TAILQ_FIRST(&head->queue));
}
/*
* number of buffer hash entries
*/
#define BUFHSZ 512
/*
* buffer hash table calculation, originally by David Greenman
*/
#define BUFHASH(vnp, bn) \
(&bufhashtbl[(((uintptr_t)(vnp) >> 7)+(int)(bn)) % BUFHSZ])
/*
* Definitions for the buffer free lists.
*/
#define BUFFER_QUEUES 6 /* number of free 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 int needsbuffer, numdirtybuffers;
extern TAILQ_HEAD(swqueue, buf) bswlist;
extern TAILQ_HEAD(bqueues, buf) bufqueues[BUFFER_QUEUES];
struct uio;
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 *));
void bdirty __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((int *));
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 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 *, long, int, 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 __P((struct buf *));
void vwakeup __P((struct buf *));
void vmapbuf __P((struct buf *));
void vunmapbuf __P((struct buf *));
void relpbuf __P((struct buf *, int *));
void brelvp __P((struct buf *));
void bgetvp __P((struct vnode *, struct buf *));
void pbgetvp __P((struct vnode *, struct buf *));
void pbrelvp __P((struct buf *));
int allocbuf __P((struct buf *bp, int size));
void reassignbuf __P((struct buf *, struct vnode *));
void pbreassignbuf __P((struct buf *, struct vnode *));
struct buf *trypbuf __P((int *));
void vfs_bio_need_satisfy __P((void));
#endif /* KERNEL */
#endif /* !_SYS_BUF_H_ */
