/* * Copyright (c) 2000-2008 Apple Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. The rights granted to you under the License * may not be used to create, or enable the creation or redistribution of, * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */ /* * 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 */ #ifndef _SYS_BUF_INTERNAL_H_ #define _SYS_BUF_INTERNAL_H_ #include <sys/appleapiopts.h> #ifdef KERNEL #include <sys/queue.h> #include <sys/errno.h> #include <sys/vm.h> #include <sys/cdefs.h> #include <sys/buf.h> #include <sys/lock.h> #define NOLIST ((struct buf *)0x87654321) /* * 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. */ int b_timestamp; /* timestamp for queuing operation */ int b_whichq; /* the free list the buffer belongs to */ volatile uint32_t b_flags; /* B_* flags. */ volatile uint32_t b_lflags; /* BL_BUSY | BL_WANTED flags... protected by buf_mtx */ int b_error; /* errno value. */ int b_bufsize; /* Allocated buffer size. */ int b_bcount; /* Valid bytes in buffer. */ int b_resid; /* Remaining I/O. */ dev_t b_dev; /* Device associated with buffer. */ uintptr_t b_datap; /* Memory, superblocks, indirect etc.*/ daddr64_t b_lblkno; /* Logical block number. */ daddr64_t b_blkno; /* Underlying physical block number. */ void (*b_iodone)(buf_t, void *); /* Function to call upon completion. */ vnode_t b_vp; /* File vnode for data, device vnode for metadata. */ kauth_cred_t b_rcred; /* Read credentials reference. */ kauth_cred_t b_wcred; /* Write credentials reference. */ void * b_upl; /* Pointer to UPL */ buf_t b_real_bp; /* used to track bp generated through cluster_bp */ TAILQ_ENTRY(buf) b_act; /* Device driver queue when active */ void * b_drvdata; /* Device driver private use */ void * b_fsprivate; /* filesystem private use */ void * b_transaction; /* journal private use */ 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. */ proc_t b_proc; /* Associated proc; NULL if kernel. */ #if CONFIG_PROTECT struct cprotect *b_cpentry; /* address of cp_entry, to be passed further down */ #endif /* CONFIG_PROTECT */ #ifdef JOE_DEBUG void * b_owner; int b_tag; void * b_lastbrelse; void * b_stackbrelse[6]; void * b_stackgetblk[6]; #endif }; /* cluster_io definitions for use with io bufs */ #define b_uploffset b_bufsize #define b_trans_head b_freelist.tqe_prev #define b_trans_next b_freelist.tqe_next #define b_iostate b_rcred #define b_cliodone b_wcred /* * These flags are kept in b_lflags... * buf_mtxp must be held before examining/updating */ #define BL_BUSY 0x00000001 /* I/O in progress. */ #define BL_WANTED 0x00000002 /* Process wants this buffer. */ #define BL_IOBUF 0x00000004 /* buffer allocated via 'buf_alloc' */ #define BL_CALLDONE 0x00000008 /* callback routine on B_CALL bp has completed */ #define BL_WANTDEALLOC 0x00000010 /* buffer should be put on empty list when clean */ /* * Parameters for buffer cache garbage collection */ #define BUF_STALE_THRESHHOLD 30 /* Collect if untouched in the last 30 seconds */ #define BUF_MAX_GC_COUNT 1000 /* Generally 6-8 MB */ /* * mask used by buf_flags... these are the readable external flags */ #define BUF_X_RDFLAGS (B_PHYS | B_RAW | B_LOCKED | B_ASYNC | B_READ | B_WRITE | B_PAGEIO |\ B_META | B_CLUSTER | B_DELWRI | B_FUA | B_PASSIVE | B_IOSTREAMING | B_THROTTLED_IO) /* * mask used by buf_clearflags/buf_setflags... these are the writable external flags */ #define BUF_X_WRFLAGS (B_PHYS | B_RAW | B_LOCKED | B_ASYNC | B_READ | B_WRITE | B_PAGEIO |\ B_NOCACHE | B_FUA | B_PASSIVE | B_IOSTREAMING) /* * These flags are kept in b_flags... access is lockless * External flags are defined in buf.h and cannot overlap * the internal flags * * these flags are internal... there definition may change */ #define B_CACHE 0x00010000 /* getblk found us in the cache. */ #define B_DONE 0x00020000 /* I/O completed. */ #define B_INVAL 0x00040000 /* Does not contain valid info. */ #define B_ERROR 0x00080000 /* I/O error occurred. */ #define B_EINTR 0x00100000 /* I/O was interrupted */ #define B_AGE 0x00200000 /* Move to age queue when I/O done. */ #define B_FILTER 0x00400000 /* call b_iodone from biodone as an in-line filter */ #define B_CALL 0x00800000 /* Call b_iodone from biodone, assumes b_iodone consumes bp */ #define B_EOT 0x01000000 /* last buffer in a transaction list created by cluster_io */ #define B_WASDIRTY 0x02000000 /* page was found dirty in the VM cache */ #define B_HDRALLOC 0x04000000 /* zone allocated buffer header */ #define B_ZALLOC 0x08000000 /* b_datap is zalloc()ed */ /* * private flags used by the journal layer */ #define B_NORELSE 0x10000000 /* don't brelse() in bwrite() */ /* * private flags used by by the cluster layer */ #define B_NEED_IODONE 0x20000000 /* need biodone on the real_bp associated with a cluster_io */ #define B_COMMIT_UPL 0x40000000 /* commit/abort the UPL on I/O success/failure */ /* Flags to low-level allocation routines. */ #define B_CLRBUF 0x01 /* Request allocated buffer be cleared. */ #define B_SYNC 0x02 /* Do all allocations synchronously. */ #define B_NOBUFF 0x04 /* Do not allocate struct buf */ extern int niobuf_headers; /* The number of IO buffer headers for cluster IO */ extern int nbuf_headers; /* The number of buffer headers */ extern int max_nbuf_headers; /* The max number of buffer headers */ extern int nbuf_hashelements; /* The number of elements in bufhash */ extern struct buf *buf_headers; /* The buffer headers. */ /* * Definitions for the buffer free lists. */ #define BQUEUES 6 /* number of free buffer queues */ #define BQ_LOCKED 0 /* super-blocks &c */ #define BQ_LRU 1 /* lru, useful buffers */ #define BQ_AGE 2 /* rubbish */ #define BQ_EMPTY 3 /* buffer headers with no memory */ #define BQ_META 4 /* buffer containing metadata */ #define BQ_LAUNDRY 5 /* buffers that need cleaning */ __BEGIN_DECLS buf_t alloc_io_buf(vnode_t, int); void free_io_buf(buf_t); int allocbuf(struct buf *, int); void bufinit(void) __attribute__((section("__TEXT, initcode"))); /* * Flags for buf_acquire */ #define BAC_NOWAIT 0x01 /* Don't wait if buffer is busy */ #define BAC_REMOVE 0x02 /* Remove from free list once buffer is acquired */ #define BAC_SKIP_NONLOCKED 0x04 /* Don't return LOCKED buffers */ #define BAC_SKIP_LOCKED 0x08 /* Only return LOCKED buffers */ void buf_list_lock(void); void buf_list_unlock(void); void buf_biowait_callback(buf_t); void cluster_init(void) __attribute__((section("__TEXT, initcode"))); void buf_drop(buf_t); errno_t buf_acquire(buf_t, int, int, int); int count_busy_buffers(void); int count_lock_queue(void); __END_DECLS /* * Stats on usefulness of the buffer cache */ struct bufstats { long bufs_incore; /* found incore */ long bufs_busyincore; /* found incore. was busy */ long bufs_vmhits; /* not incore. found in VM */ long bufs_miss; /* not incore. not in VM */ long bufs_sleeps; /* buffer starvation */ long bufs_eblk; /* Calls to geteblk */ long bufs_iobufmax; /* Max. number of IO buffers used */ long bufs_iobufinuse; /* number of IO buffers in use */ long bufs_iobufsleeps; /* IO buffer starvation */ }; #endif /* KERNEL */ #endif /* !_SYS_BUF_H_ */