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IABSD.fr/src/sys/sys/buf.h
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- sys/sys/buf.h
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/* $OpenBSD: buf.h,v 1.118 2025/06/08 06:23:43 rsadowski 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); /* * 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); void bufq_destroy(struct bufq *); void bufq_queue(struct bufq *, struct buf *); struct buf *bufq_dequeue(struct bufq *); 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; }; /* 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. */ }; TAILQ_HEAD(bufqueue, buf); struct bufcache { int64_t hotbufpages; int64_t warmbufpages; int64_t cachepages; struct bufqueue hotqueue; struct bufqueue coldqueue; struct bufqueue warmqueue; }; /* * 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 *); 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_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_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 *); int buf_realloc_pages(struct buf *, struct uvm_constraint_range *, int); 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 **); __END_DECLS #endif /* _KERNEL */ #endif /* !_SYS_BUF_H_ */