/* * 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 struct buf; struct mount; struct vnode; /* * To avoid including */ 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_ */