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Diffstat (limited to 'sys/sys/buf.h')
| -rw-r--r-- | sys/sys/buf.h | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/sys/sys/buf.h b/sys/sys/buf.h new file mode 100644 index 0000000..ea01ac0 --- /dev/null +++ b/sys/sys/buf.h @@ -0,0 +1,374 @@ +/* $OpenBSD: buf.h,v 1.112 2019/11/29 01:04:08 beck Exp $ */ +/* $NetBSD: buf.h,v 1.25 1997/04/09 21:12:17 mycroft Exp $ */ + +/* + * 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. 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> +#include <sys/tree.h> +#include <sys/mutex.h> +#include <uvm/uvm_extern.h> + +#define NOLIST ((struct buf *)0x87654321) + +struct buf; +struct vnode; + +LIST_HEAD(bufhead, buf); + +/* + * To avoid including <ufs/ffs/softdep.h> + */ + +LIST_HEAD(workhead, worklist); + +/* + * Buffer queues + */ +#define BUFQ_NSCAN_N 128 +#define BUFQ_FIFO 0 +#define BUFQ_NSCAN 1 +#define BUFQ_DEFAULT BUFQ_NSCAN +#define BUFQ_HOWMANY 2 + +/* + * Write limits for bufq - defines high and low water marks for how + * many kva slots are allowed to be consumed to parallelize writes from + * the buffer cache from any individual bufq. + */ +#define BUFQ_HI 128 +#define BUFQ_LOW 64 + +struct bufq_impl; + +struct bufq { + SLIST_ENTRY(bufq) bufq_entries; + struct mutex bufq_mtx; + void *bufq_data; + u_int bufq_outstanding; + u_int bufq_hi; + u_int bufq_low; + int bufq_waiting; + int bufq_stop; + int bufq_type; + const struct bufq_impl *bufq_impl; +}; + +int bufq_init(struct bufq *, int); +int bufq_switch(struct bufq *, int); +void bufq_destroy(struct bufq *); + +void bufq_queue(struct bufq *, struct buf *); +struct buf *bufq_dequeue(struct bufq *); +void bufq_requeue(struct bufq *, struct buf *); +int bufq_peek(struct bufq *); +void bufq_drain(struct bufq *); + +void bufq_wait(struct bufq *); +void bufq_done(struct bufq *, struct buf *); +void bufq_quiesce(void); +void bufq_restart(void); + +/* fifo */ +SIMPLEQ_HEAD(bufq_fifo_head, buf); +struct bufq_fifo { + SIMPLEQ_ENTRY(buf) bqf_entries; +}; + +/* nscan */ +SIMPLEQ_HEAD(bufq_nscan_head, buf); +struct bufq_nscan { + SIMPLEQ_ENTRY(buf) bqf_entries; +}; + +/* bufq link in struct buf */ +union bufq_data { + struct bufq_fifo bufq_data_fifo; + struct bufq_nscan bufq_data_nscan; +}; + +/* + * 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)(struct buf *); + void (*io_complete)(struct buf *); + void (*io_deallocate)(struct buf *); + void (*io_movedeps)(struct buf *, struct buf *); + int (*io_countdeps)(struct buf *, int, int); +} bioops; + +/* The buffer header describes an I/O operation in the kernel. */ +struct buf { + RBT_ENTRY(buf) b_rbbufs; /* vnode "hash" tree */ + LIST_ENTRY(buf) b_list; /* All allocated buffers. */ + LIST_ENTRY(buf) b_vnbufs; /* Buffer's associated vnode. */ + TAILQ_ENTRY(buf) b_freelist; /* Free list position if not active. */ + int cache; /* which cache are we in */ + struct proc *b_proc; /* Associated proc; NULL if kernel. */ + volatile long b_flags; /* B_* flags. */ + long b_bufsize; /* Allocated buffer size. */ + long b_bcount; /* Valid bytes in buffer. */ + size_t b_resid; /* Remaining I/O. */ + int b_error; /* Errno value. */ + dev_t b_dev; /* Device associated with buffer. */ + caddr_t b_data; /* associated data */ + void *b_saveaddr; /* Original b_data for physio. */ + + TAILQ_ENTRY(buf) b_valist; /* LRU of va to reuse. */ + + union bufq_data b_bufq; + struct bufq *b_bq; /* What bufq this buf is on */ + + struct uvm_object *b_pobj; + struct uvm_object b_uobj; /* Object containing the pages */ + off_t b_poffs; /* Offset within object */ + + daddr_t b_lblkno; /* Logical block number. */ + daddr_t b_blkno; /* Underlying physical block number. */ + /* Function to call upon completion. + * Will be called at splbio(). */ + void (*b_iodone)(struct buf *); + struct vnode *b_vp; /* Device vnode. */ + int b_dirtyoff; /* Offset in buffer of dirty region. */ + int b_dirtyend; /* Offset of end of dirty region. */ + int b_validoff; /* Offset in buffer of valid region. */ + int b_validend; /* Offset of end of valid region. */ + struct workhead b_dep; /* List of filesystem dependencies. */ +}; + +TAILQ_HEAD(bufqueue, buf); + +struct bufcache { + int64_t hotbufpages; + int64_t warmbufpages; + int64_t cachepages; + struct bufqueue hotqueue; + struct bufqueue coldqueue; + struct bufqueue warmqueue; +}; + +/* Device driver compatibility definitions. */ +#define b_active b_bcount /* Driver queue head: drive active. */ + +/* + * These flags are kept in b_flags. + */ +#define B_WRITE 0x00000000 /* Write buffer (pseudo flag). */ +#define B_AGE 0x00000001 /* Move to age queue when I/O done. */ +#define B_NEEDCOMMIT 0x00000002 /* Needs committing to stable storage */ +#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_DONE 0x00000100 /* I/O completed. */ +#define B_EINTR 0x00000200 /* I/O was interrupted */ +#define B_ERROR 0x00000400 /* I/O error occurred. */ +#define B_INVAL 0x00000800 /* Does not contain valid info. */ +#define B_NOCACHE 0x00001000 /* Do not cache block after use. */ +#define B_PHYS 0x00002000 /* I/O to user memory. */ +#define B_RAW 0x00004000 /* Set by physio for raw transfers. */ +#define B_READ 0x00008000 /* Read buffer. */ +#define B_WANTED 0x00010000 /* Process wants this buffer. */ +#define B_WRITEINPROG 0x00020000 /* Write in progress. */ +#define B_XXX 0x00040000 /* Debugging flag. */ +#define B_DEFERRED 0x00080000 /* Skipped over for cleaning */ +#define B_SCANNED 0x00100000 /* Block already pushed during sync */ +#define B_PDAEMON 0x00200000 /* I/O started by pagedaemon */ +#define B_RELEASED 0x00400000 /* free this buffer after its kvm */ +#define B_WARM 0x00800000 /* buffer is or has been on the warm queue */ +#define B_COLD 0x01000000 /* buffer is on the cold queue */ +#define B_BC 0x02000000 /* buffer is managed by the cache */ +#define B_DMA 0x04000000 /* buffer is DMA reachable */ + +#define B_BITS "\20\001AGE\002NEEDCOMMIT\003ASYNC\004BAD\005BUSY" \ + "\006CACHE\007CALL\010DELWRI\011DONE\012EINTR\013ERROR" \ + "\014INVAL\015NOCACHE\016PHYS\017RAW\020READ" \ + "\021WANTED\022WRITEINPROG\023XXX(FORMAT)\024DEFERRED" \ + "\025SCANNED\026DAEMON\027RELEASED\030WARM\031COLD\032BC\033DMA" + +/* + * Zero out the buffer's data area. + */ +#define clrbuf(bp) { \ + bzero((bp)->b_data, (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. */ + +struct cluster_info { + daddr_t ci_lastr; /* last read (read-ahead) */ + daddr_t ci_lastw; /* last write (write cluster) */ + daddr_t ci_cstart; /* start block of cluster */ + daddr_t ci_lasta; /* last allocation */ + int ci_clen; /* length of current cluster */ + int ci_ralen; /* Read-ahead length */ + daddr_t ci_maxra; /* last readahead block */ +}; + +#ifdef _KERNEL +__BEGIN_DECLS +/* Kva slots (of size MAXPHYS) reserved for syncer and cleaner. */ +#define RESERVE_SLOTS 4 +/* Buffer cache pages reserved for syncer and cleaner. */ +#define RESERVE_PAGES (RESERVE_SLOTS * MAXPHYS / PAGE_SIZE) +/* Minimum size of the buffer cache, in pages. */ +#define BCACHE_MIN (RESERVE_PAGES * 2) +#define UNCLEAN_PAGES (bcstats.numbufpages - bcstats.numcleanpages) + +extern struct proc *cleanerproc; +extern long bufpages; /* Max number of pages for buffers' data */ +extern struct pool bufpool; +extern struct bufhead bufhead; + +void bawrite(struct buf *); +void bdwrite(struct buf *); +void biodone(struct buf *); +int biowait(struct buf *); +int bread(struct vnode *, daddr_t, int, struct buf **); +int breadn(struct vnode *, daddr_t, int, daddr_t *, int *, int, + struct buf **); +void brelse(struct buf *); +#define bremfree bufcache_take +void bufinit(void); +void buf_dirty(struct buf *); +void buf_undirty(struct buf *); +void buf_adjcnt(struct buf *, long); +int bwrite(struct buf *); +struct buf *getblk(struct vnode *, daddr_t, int, int, uint64_t); +struct buf *geteblk(size_t); +struct buf *incore(struct vnode *, daddr_t); + +/* + * bufcache functions + */ +void bufcache_take(struct buf *); +void bufcache_release(struct buf *); + +int buf_flip_high(struct buf *); +void buf_flip_dma(struct buf *); +struct buf *bufcache_getcleanbuf(int, int); +struct buf *bufcache_getanycleanbuf(void); +struct buf *bufcache_getdirtybuf(void); + +/* + * buf_kvm_init initializes the kvm handling for buffers. + * buf_acquire sets the B_BUSY flag and ensures that the buffer is + * mapped in the kvm. + * buf_release clears the B_BUSY flag and allows the buffer to become + * unmapped. + * buf_unmap is for internal use only. Unmaps the buffer from kvm. + */ +void buf_mem_init(vsize_t); +void buf_acquire(struct buf *); +void buf_acquire_unmapped(struct buf *); +void buf_acquire_nomap(struct buf *); +void buf_map(struct buf *); +void buf_release(struct buf *); +int buf_dealloc_mem(struct buf *); +void buf_fix_mapping(struct buf *, vsize_t); +void buf_alloc_pages(struct buf *, vsize_t); +void buf_free_pages(struct buf *); + +void minphys(struct buf *bp); +int physio(void (*strategy)(struct buf *), dev_t dev, int flags, + void (*minphys)(struct buf *), struct uio *uio); +void brelvp(struct buf *); +void reassignbuf(struct buf *); +void bgetvp(struct vnode *, struct buf *); + +void buf_replacevnode(struct buf *, struct vnode *); +void buf_daemon(void *); +void buf_replacevnode(struct buf *, struct vnode *); +int bread_cluster(struct vnode *, daddr_t, int, struct buf **); + +#ifdef DEBUG +void buf_print(struct buf *); +#endif + +static __inline void +buf_start(struct buf *bp) +{ + if (bioops.io_start) + (*bioops.io_start)(bp); +} + +static __inline void +buf_complete(struct buf *bp) +{ + if (bioops.io_complete) + (*bioops.io_complete)(bp); +} + +static __inline void +buf_deallocate(struct buf *bp) +{ + if (bioops.io_deallocate) + (*bioops.io_deallocate)(bp); +} + +static __inline void +buf_movedeps(struct buf *bp, struct buf *bp2) +{ + if (bioops.io_movedeps) + (*bioops.io_movedeps)(bp, bp2); +} + +static __inline int +buf_countdeps(struct buf *bp, int i, int islocked) +{ + if (bioops.io_countdeps) + return ((*bioops.io_countdeps)(bp, i, islocked)); + else + return (0); +} + +void cluster_write(struct buf *, struct cluster_info *, u_quad_t); + +__END_DECLS +#endif /* _KERNEL */ +#endif /* !_SYS_BUF_H_ */ |