X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/e5568f75972dfc723778653c11cb6b4dc825716a..7ee9d059c4eecf68ae4f8b0fb99ae2471eda79af:/bsd/sys/buf.h?ds=sidebyside diff --git a/bsd/sys/buf.h b/bsd/sys/buf.h index 86ceeeb96..f1d7f924b 100644 --- a/bsd/sys/buf.h +++ b/bsd/sys/buf.h @@ -1,23 +1,29 @@ /* - * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * - * The contents of this file constitute Original Code as defined in and - * are subject to the Apple Public Source License Version 1.1 (the - * "License"). You may not use this file except in compliance with the - * License. Please obtain a copy of the License at - * http://www.apple.com/publicsource and read it before using this file. + * 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. * - * This Original Code and all software distributed under the License are - * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER + * 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 OR NON-INFRINGEMENT. Please see the - * License for the specific language governing rights and limitations - * under the License. + * 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_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */ /* @@ -63,226 +69,991 @@ #ifndef _SYS_BUF_H_ #define _SYS_BUF_H_ -#include - -#ifdef KERNEL -#include -#include -#include #include +#include +#include +#include -#ifdef __APPLE_API_PRIVATE - -#define NOLIST ((struct buf *)0x87654321) +#define B_WRITE 0x00000000 /* Write buffer (pseudo flag). */ +#define B_READ 0x00000001 /* Read buffer. */ +#define B_ASYNC 0x00000002 /* Start I/O, do not wait. */ +#define B_NOCACHE 0x00000004 /* Do not cache block after use. */ +#define B_DELWRI 0x00000008 /* Delay I/O until buffer reused. */ +#define B_LOCKED 0x00000010 /* Locked in core (not reusable). */ +#define B_PHYS 0x00000020 /* I/O to user memory. */ +#define B_CLUSTER 0x00000040 /* UPL based I/O generated by cluster layer */ +#define B_PAGEIO 0x00000080 /* Page in/out */ +#define B_META 0x00000100 /* buffer contains meta-data. */ +#define B_RAW 0x00000200 /* Set by physio for raw transfers. */ +#define B_FUA 0x00000400 /* Write-through disk cache(if supported) */ +#define B_PASSIVE 0x00000800 /* PASSIVE I/Os are ignored by THROTTLE I/O */ +#define B_IOSTREAMING 0x00001000 /* sequential access pattern detected */ +#define B_THROTTLED_IO 0x00002000 /* low priority I/O */ +#define B_ENCRYPTED_IO 0x00004000 /* Encrypted I/O */ /* - * 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. */ - struct proc *b_proc; /* Associated proc; NULL if kernel. */ - volatile long b_flags; /* B_* 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. */ - struct { - caddr_t b_addr; /* Memory, superblocks, indirect etc.*/ - } b_un; - void *b_saveaddr; /* Original b_addr for physio. */ - daddr_t b_lblkno; /* Logical block number. */ - daddr_t b_blkno; /* Underlying physical block number. */ - /* Function to call upon completion. */ - void (*b_iodone) __P((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 ucred *b_rcred; /* Read credentials reference. */ - struct ucred *b_wcred; /* Write credentials reference. */ - int b_timestamp; /* timestamp for queuing operation */ - long b_vectorcount; /* number of vectors in b_vectorlist */ - void *b_vectorlist; /* vector list for I/O */ - void *b_pagelist; /* to save pagelist info */ - long b_vects[2]; /* vectorlist when b_vectorcount is 1 */ - long b_whichq; /* the free list the buffer belongs to */ - TAILQ_ENTRY(buf) b_act; /* Device driver queue when active */ - void *b_drvdata; /* Device driver private use */ -}; + * make sure to check when adding flags that + * that the new flags don't overlap the definitions + * in buf_internal.h + */ -/* - * For portability with historic industry practice, the cylinder number has - * to be maintained in the `b_resid' field. +__BEGIN_DECLS + +/*! + @function buf_markaged + @abstract Mark a buffer as "aged," i.e. as a good candidate to be discarded and reused after buf_brelse(). + @param bp Buffer to mark. + */ +void buf_markaged(buf_t); + +/*! + @function buf_markinvalid + @abstract Mark a buffer as not having valid data and being ready for immediate reuse after buf_brelse(). + @param bp Buffer to mark. */ -#define b_cylinder b_resid /* Cylinder number for disksort(). */ +void buf_markinvalid(buf_t); -/* Device driver compatibility definitions. */ -#define b_active b_bcount /* Driver queue head: drive active. */ -#define b_data b_un.b_addr /* b_un.b_addr is not changeable. */ -#define b_errcnt b_resid /* Retry count while I/O in progress. */ -#define iodone biodone /* Old name for biodone. */ -#define iowait biowait /* Old name for biowait. */ +/*! + @function buf_markdelayed + @abstract Mark a buffer as a delayed write: mark it dirty without actually scheduling I/O. + @discussion Data will be flushed to disk at some later time, not with brelse(). A sync()/fsync() + or pressure necessitating reuse of the buffer will cause it to be written back to disk. + @param bp Buffer to mark. + */ +void buf_markdelayed(buf_t); -/* 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_real_bp b_saveaddr -#define b_iostate b_rcred +void buf_markclean(buf_t); -/* journaling uses this cluster i/o field for its own - * purposes because meta data buf's should never go - * through the clustering code. +/*! + @function buf_markeintr + @abstract Mark a buffer as having been interrupted during I/O. + @discussion Waiters for I/O to complete (buf_biowait()) will return with EINTR when woken up. + buf_markeintr does not itself do a wakeup. + @param bp Buffer to mark. */ -#define b_transaction b_vectorlist +void buf_markeintr(buf_t); - +/*! + @function buf_markfua + @abstract Mark a buffer for write through disk cache, if disk supports it. + @param bp Buffer to mark. + */ +void buf_markfua(buf_t); + +/*! + @function buf_fua + @abstract Check if a buffer is marked for write through disk caches. + @param bp Buffer to test. + @return Nonzero if buffer is marked for write-through, 0 if not. + */ +int buf_fua(buf_t); + +/*! + @function buf_valid + @abstract Check if a buffer contains valid data. + @param bp Buffer to test. + @return Nonzero if buffer has valid data, 0 if not. + */ +int buf_valid(buf_t); + +/*! + @function buf_fromcache + @abstract Check if a buffer's data was found in core. + @discussion Will return truth after a buf_getblk that finds a valid buffer in the cache or the relevant + data in core (but not in a buffer). + @param bp Buffer to test. + @return Nonzero if we got this buffer's data without doing I/O, 0 if not. + */ +int buf_fromcache(buf_t); + +/*! + @function buf_upl + @abstract Get the upl (Universal Page List) associated with a buffer. + @discussion Buffers allocated with buf_alloc() are not returned with a upl, and + traditional buffers only have a upl while an I/O is in progress. + @param bp Buffer whose upl to grab. + @return Buffer's upl if it has one, else NULL. + */ +void * buf_upl(buf_t); + +/*! + @function buf_uploffset + @abstract Get the offset into a UPL at which this buffer begins. + @discussion This function should only be called on iobufs, i.e. buffers allocated with buf_alloc(). + @param bp Buffer whose uploffset to grab. + @return Buffer's uploffset--does not check whether that value makes sense for this buffer. + */ +uint32_t buf_uploffset(buf_t); + +/*! + @function buf_rcred + @abstract Get the credential associated with a buffer for reading. + @discussion No reference is taken; if the credential is to be held on to persistently, an additional + reference must be taken with kauth_cred_ref. + @param bp Buffer whose credential to grab. + @return Credential if it exists, else NULL. + */ +kauth_cred_t buf_rcred(buf_t); + +/*! + @function buf_wcred + @abstract Get the credential associated with a buffer for writing. + @discussion No reference is taken; if the credential is to be held on to persistently, an additional + reference must be taken with kauth_cred_ref. + @param bp Buffer whose credential to grab. + @return Credential if it exists, else NULL. + */ +kauth_cred_t buf_wcred(buf_t); + +/*! + @function buf_proc + @abstract Get the process associated with this buffer. + @discussion buf_proc() will generally return NULL; a process is currently only associated with + a buffer in the event of a physio() call. + @param bp Buffer whose associated process to find. + @return Associated process, possibly NULL. + */ +proc_t buf_proc(buf_t); + +/*! + @function buf_dirtyoff + @abstract Get the starting offset of the dirty region associated with a buffer. + @discussion The dirty offset is zero unless someone explicitly calls buf_setdirtyoff() (which the kernel does not). + @param bp Buffer whose dirty offset to get. + @return Dirty offset (0 if not explicitly changed). + */ +uint32_t buf_dirtyoff(buf_t); + +/*! + @function buf_dirtyend + @abstract Get the ending offset of the dirty region associated with a buffer. + @discussion If the buffer's data was found incore and dirty, the dirty end is the size of the block; otherwise, unless + someone outside of xnu explicitly changes it by calling buf_setdirtyend(), it will be zero. + @param bp Buffer whose dirty end to get. + @return 0 if buffer is found clean; size of buffer if found dirty. Can be set to any value by callers of buf_setdirtyend(). + */ +uint32_t buf_dirtyend(buf_t); + +/*! + @function buf_setdirtyoff + @abstract Set the starting offset of the dirty region associated with a buffer. + @discussion This value is zero unless someone set it explicitly. + @param bp Buffer whose dirty end to set. + @return void. + */ +void buf_setdirtyoff(buf_t, uint32_t); + +/*! + @function buf_setdirtyend + @abstract Set the ending offset of the dirty region associated with a buffer. + @discussion If the buffer's data was found incore and dirty, the dirty end is the size of the block; otherwise, unless + someone outside of xnu explicitly changes it by calling buf_setdirtyend(), it will be zero. + @param bp Buffer whose dirty end to set. + @return void. + */ +void buf_setdirtyend(buf_t, uint32_t); + +/*! + @function buf_error + @abstract Get the error value associated with a buffer. + @discussion Errors are set with buf_seterror(). + @param bp Buffer whose error value to retrieve. + @return Error value, directly. + */ +errno_t buf_error(buf_t); + +/*! + @function buf_seterror + @abstract Set an error value on a buffer. + @param bp Buffer whose error value to set. + @return void. + */ +void buf_seterror(buf_t, errno_t); + +/*! + @function buf_setflags + @abstract Set flags on a buffer. + @discussion: buffer_flags |= flags + @param bp Buffer whose flags to set. + @param flags Flags to add to buffer's mask. B_LOCKED/B_NOCACHE/B_ASYNC/B_READ/B_WRITE/B_PAGEIO/B_FUA + @return void. + */ +void buf_setflags(buf_t, int32_t); + +/*! + @function buf_clearflags + @abstract Clear flags on a buffer. + @discussion: buffer_flags &= ~flags + @param bp Buffer whose flags to clear. + @param flags Flags to remove from buffer's mask. B_LOCKED/B_NOCACHE/B_ASYNC/B_READ/B_WRITE/B_PAGEIO/B_FUA + @return void. + */ +void buf_clearflags(buf_t, int32_t); + +/*! + @function buf_flags + @abstract Get flags set on a buffer. + @discussion Valid flags are B_LOCKED/B_NOCACHE/B_ASYNC/B_READ/B_WRITE/B_PAGEIO/B_FUA. + @param bp Buffer whose flags to grab. + @return flags. + */ +int32_t buf_flags(buf_t); + +/*! + @function buf_reset + @abstract Reset I/O flag state on a buffer. + @discussion Clears current flags on a buffer (internal and external) and allows some new flags to be set. + Used perhaps to prepare an iobuf for reuse. + @param bp Buffer whose flags to grab. + @param flags Flags to set on buffer: B_READ, B_WRITE, B_ASYNC, B_NOCACHE. + @return void. + */ +void buf_reset(buf_t, int32_t); + +/*! + @function buf_map + @abstract Get virtual mappings for buffer data. + @discussion For buffers created through buf_getblk() (i.e. traditional buffer cache usage), + buf_map() just returns the address at which data was mapped by but_getblk(). For a B_CLUSTER buffer, i.e. an iobuf + whose upl state is managed manually, there are two possibilities. If the buffer was created + with an underlying "real" buffer through cluster_bp(), the mapping of the "real" buffer is returned. + Otherwise, the buffer was created with buf_alloc() and buf_setupl() was subsequently called; buf_map() + will call ubc_upl_map() to get a mapping for the buffer's upl and return the start of that mapping + plus the buffer's upl offset (set in buf_setupl()). In the last case, buf_unmap() must later be called + to tear down the mapping. NOTE: buf_map() does not set the buffer data pointer; this must be done with buf_setdataptr(). + @param bp Buffer whose mapping to find or create. + @param io_addr Destination for mapping address. + @return 0 for success, ENOMEM if unable to map the buffer. + */ +errno_t buf_map(buf_t, caddr_t *); + +/*! + @function buf_unmap + @abstract Release mappings for buffer data. + @discussion For buffers created through buf_getblk() (i.e. traditional buffer cache usage), + buf_unmap() does nothing; buf_brelse() will take care of unmapping. For a B_CLUSTER buffer, i.e. an iobuf + whose upl state is managed manually, there are two possibilities. If the buffer was created + with an underlying "real" buffer through cluster_bp(), buf_unmap() does nothing; buf_brelse() on the + underlying buffer will tear down the mapping. Otherwise, the buffer was created with buf_alloc() and + buf_setupl() was subsequently called; buf_map() created the mapping. In this case, buf_unmap() will + unmap the buffer. + @param bp Buffer whose mapping to find or create. + @param io_addr Destination for mapping address. + @return 0 for success, EINVAL if unable to unmap buffer. + */ +errno_t buf_unmap(buf_t); + +/*! + @function buf_setdrvdata + @abstract Set driver-specific data on a buffer. + @param bp Buffer whose driver-data to set. + @param drvdata Opaque driver data. + @return void. + */ +void buf_setdrvdata(buf_t, void *); + +/*! + @function buf_setdrvdata + @abstract Get driver-specific data from a buffer. + @param bp Buffer whose driver data to get. + @return Opaque driver data. + */ +void * buf_drvdata(buf_t); + +/*! + @function buf_setfsprivate + @abstract Set filesystem-specific data on a buffer. + @param bp Buffer whose filesystem data to set. + @param fsprivate Opaque filesystem data. + @return void. + */ +void buf_setfsprivate(buf_t, void *); + +/*! + @function buf_fsprivate + @abstract Get filesystem-specific data from a buffer. + @param bp Buffer whose filesystem data to get. + @return Opaque filesystem data. + */ +void * buf_fsprivate(buf_t); + +/*! + @function buf_blkno + @abstract Get physical block number associated with a buffer, in the sense of VNOP_BLOCKMAP. + @discussion When a buffer's physical block number is the same is its logical block number, then the physical + block number is considered uninitialized. A physical block number of -1 indicates that there is no valid + physical mapping (e.g. the logical block is invalid or corresponds to a sparse region in a file). Physical + block number is normally set by the cluster layer or by buf_getblk(). + @param bp Buffer whose physical block number to get. + @return Block number. + */ +daddr64_t buf_blkno(buf_t); + +/*! + @function buf_lblkno + @abstract Get logical block number associated with a buffer. + @discussion Logical block number is set on traditionally-used buffers by an argument passed to buf_getblk(), + for example by buf_bread(). + @param bp Buffer whose logical block number to get. + @return Block number. + */ +daddr64_t buf_lblkno(buf_t); + +/*! + @function buf_setblkno + @abstract Set physical block number associated with a buffer. + @discussion Physical block number is generally set by the cluster layer or by buf_getblk(). + @param bp Buffer whose physical block number to set. + @param blkno Block number to set. + @return void. + */ +void buf_setblkno(buf_t, daddr64_t); + +/*! + @function buf_setlblkno + @abstract Set logical block number associated with a buffer. + @discussion Logical block number is set on traditionally-used buffers by an argument passed to buf_getblk(), + for example by buf_bread(). + @param bp Buffer whose logical block number to set. + @param lblkno Block number to set. + @return void. + */ +void buf_setlblkno(buf_t, daddr64_t); + +/*! + @function buf_count + @abstract Get count of valid bytes in a buffer. This may be less than the space allocated to the buffer. + @param bp Buffer whose byte count to get. + @return Byte count. + */ +uint32_t buf_count(buf_t); + +/*! + @function buf_size + @abstract Get size of data region allocated to a buffer. + @discussion May be larger than amount of valid data in buffer. + @param bp Buffer whose size to get. + @return Size. + */ +uint32_t buf_size(buf_t); + +/*! + @function buf_resid + @abstract Get a count of bytes which were not consumed by an I/O on a buffer. + @discussion Set when an I/O operations completes. + @param bp Buffer whose outstanding count to get. + @return Count of unwritten/unread bytes. + */ +uint32_t buf_resid(buf_t); + +/*! + @function buf_setcount + @abstract Set count of valid bytes in a buffer. This may be less than the space allocated to the buffer. + @param bp Buffer whose byte count to set. + @param bcount Count to set. + @return void. + */ +void buf_setcount(buf_t, uint32_t); + +/*! + @function buf_setsize + @abstract Set size of data region allocated to a buffer. + @discussion May be larger than amount of valid data in buffer. Should be used by + code which is manually providing storage for an iobuf, one allocated with buf_alloc(). + @param bp Buffer whose size to set. + @return void. + */ +void buf_setsize(buf_t, uint32_t); + +/*! + @function buf_setresid + @abstract Set a count of bytes outstanding for I/O in a buffer. + @discussion Set when an I/O operations completes. Examples: called by IOStorageFamily when I/O + completes, often called on an "original" buffer when using a manipulated buffer to perform I/O + on behalf of the first. + @param bp Buffer whose outstanding count to set. + @return Count of unwritten/unread bytes. + */ +void buf_setresid(buf_t, uint32_t); + +/*! + @function buf_setdataptr + @abstract Set the address at which a buffer's data will be stored. + @discussion In traditional buffer use, the data pointer will be set automatically. This routine is + useful with iobufs (allocated with buf_alloc()). + @param bp Buffer whose data pointer to set. + @param data Pointer to data region. + @return void. + */ +void buf_setdataptr(buf_t, uintptr_t); + +/*! + @function buf_dataptr + @abstract Get the address at which a buffer's data is stored; for iobufs, this must + be set with buf_setdataptr(). See buf_map(). + @param bp Buffer whose data pointer to retrieve. + @return Data pointer; NULL if unset. + */ +uintptr_t buf_dataptr(buf_t); + +/*! + @function buf_vnode + @abstract Get the vnode associated with a buffer. + @discussion Every buffer is associated with a file. Because there is an I/O in flight, + there is an iocount on this vnode; it is returned WITHOUT an extra iocount, and vnode_put() + need NOT be called. + @param bp Buffer whose vnode to retrieve. + @return Buffer's vnode. + */ +vnode_t buf_vnode(buf_t); + +/*! + @function buf_setvnode + @abstract Set the vnode associated with a buffer. + @discussion This call need not be used on traditional buffers; it is for use with iobufs. + @param bp Buffer whose vnode to set. + @param vp The vnode to attach to the buffer. + @return void. + */ +void buf_setvnode(buf_t, vnode_t); + +/*! + @function buf_device + @abstract Get the device ID associated with a buffer. + @discussion In traditional buffer use, this value is NODEV until buf_strategy() is called unless + buf_getblk() was passed a device vnode. It is set on an iobuf if buf_alloc() is passed a device + vnode or if buf_setdevice() is called. + @param bp Buffer whose device ID to retrieve. + @return Device id. + */ +dev_t buf_device(buf_t); + +/*! + @function buf_setdevice + @abstract Set the device associated with a buffer. + @discussion A buffer's device is set in buf_strategy() (or in buf_getblk() if the file is a device). + It is also set on an iobuf if buf_alloc() is passed a device vnode. + @param bp Buffer whose device ID to set. + @param vp Device to set on the buffer. + @return 0 for success, EINVAL if vp is not a device file. + */ +errno_t buf_setdevice(buf_t, vnode_t); + +/*! + @function buf_strategy + @abstract Pass an I/O request for a buffer down to the device layer. + @discussion This is one of the most important routines in the buffer cache layer. For buffers obtained + through buf_getblk, it handles finding physical block numbers for the I/O (with VNOP_BLKTOOFF and + VNOP_BLOCKMAP), packaging the I/O into page-sized chunks, and initiating I/O on the disk by calling + the device's strategy routine. If a buffer's UPL has been set manually with buf_setupl(), it assumes + that the request is already correctly configured with a block number and a size divisible by page size + and will just call directly to the device. + @param devvp Device on which to perform I/O + @param ap vnop_strategy_args structure (most importantly, a buffer). + @return 0 for success, or errors from filesystem or device layers. + */ +errno_t buf_strategy(vnode_t, void *); + +/* + * Flags for buf_invalblkno() + */ +#define BUF_WAIT 0x01 + +/*! + @function buf_invalblkno + @abstract Invalidate a filesystem logical block in a file. + @discussion buf_invalblkno() tries to make the data for a given block in a file + invalid; if the buffer for that block is found in core and is not busy, we mark it + invalid and call buf_brelse() (see "flags" param for what happens if the buffer is busy). + buf_brelse(), noticing that it is invalid, will + will return the buffer to the empty-buffer list and tell the VM subsystem to abandon + the relevant pages. Data will not be written to backing store--it will be cast aside. + Note that this function will only work if the block in question has been + obtained with a buf_getblk(). If data has been read into core without using + traditional buffer cache routines, buf_invalblkno() will not be able to invalidate it--this + includes the use of iobufs. + @param bp Buffer whose block to invalidate. + @param lblkno Logical block number. + @param flags BUF_WAIT: wait for busy buffers to become unbusy and invalidate them then. Otherwise, + just return EBUSY for busy blocks. + @return 0 for success, EINVAL if vp is not a device file. + */ +errno_t buf_invalblkno(vnode_t, daddr64_t, int); + +/*! + @function buf_callback + @abstract Get the function set to be called when I/O on a buffer completes. + @discussion A function returned by buf_callback was originally set with buf_setcallback(). + @param bp Buffer whose callback to get. + @return 0 for success, or errors from filesystem or device layers. + */ +void * buf_callback(buf_t); + +/*! + @function buf_setcallback + @abstract Set a function to be called once when I/O on a buffer completes. + @discussion A one-shot callout set with buf_setcallback() will be called from buf_biodone() + when I/O completes. It will be passed the "transaction" argument as well as the buffer. + buf_setcallback() also marks the buffer as B_ASYNC. + @param bp Buffer whose callback to set. + @param callback function to use as callback. + @param transaction Additional argument to callback function. + @return 0; always succeeds. + */ +errno_t buf_setcallback(buf_t, void (*)(buf_t, void *), void *); + +/*! + @function buf_setupl + @abstract Set the UPL (Universal Page List), and offset therein, on a buffer. + @discussion buf_setupl() should only be called on buffers allocated with buf_alloc(). + A subsequent call to buf_map() will map the UPL and give back the address at which data + begins. After buf_setupl() is called, a buffer is marked B_CLUSTER; when this is the case, + buf_strategy() assumes that a buffer is correctly configured to be passed to the device + layer without modification. Passing a NULL upl will clear the upl and the B_CLUSTER flag on the + buffer. + @param bp Buffer whose upl to set. + @param upl UPL to set in the buffer. + @parma offset Offset within upl at which relevant data begin. + @return 0 for success, EINVAL if the buffer was not allocated with buf_alloc(). + */ +errno_t buf_setupl(buf_t, upl_t, uint32_t); + +/*! + @function buf_clone + @abstract Clone a buffer with a restricted range and an optional callback. + @discussion Generates a buffer which is identical to its "bp" argument except that + it spans a subset of the data of the original. The buffer to be cloned should + have been allocated with buf_alloc(). Checks its arguments to make sure + that the data subset is coherent. Optionally, adds a callback function and argument to it + to be called when I/O completes (as with buf_setcallback(), but B_ASYNC is not set). If the original buffer had + a upl set through buf_setupl(), this upl is copied to the new buffer; otherwise, the original's + data pointer is used raw. The buffer must be released with buf_free(). + @param bp Buffer to clone. + @param io_offset Offset, relative to start of data in original buffer, at which new buffer's data will begin. + @param io_size Size of buffer region in new buffer, in the sense of buf_count(). + @param iodone Callback to be called from buf_biodone() when I/O completes, in the sense of buf_setcallback(). + @param arg Argument to pass to iodone() callback. + @return NULL if io_offset/io_size combination is invalid for the buffer to be cloned; otherwise, the new buffer. + */ +buf_t buf_clone(buf_t, int, int, void (*)(buf_t, void *), void *); + + +/*! + @function buf_create_shadow + @abstract Create a shadow buffer with optional private storage and an optional callback. + @param bp Buffer to shadow. + @param force_copy If TRUE, do not link the shadaow to 'bp' and if 'external_storage' == NULL, + force a copy of the data associated with 'bp'. + @param external_storage If non-NULL, associate it with the new buffer as its storage instead of the + storage currently associated with 'bp'. + @param iodone Callback to be called from buf_biodone() when I/O completes, in the sense of buf_setcallback(). + @param arg Argument to pass to iodone() callback. + @return NULL if the buffer to be shadowed is not B_META or a primary buffer (i.e. not a shadow buffer); otherwise, the new buffer. +*/ + +buf_t buf_create_shadow(buf_t bp, boolean_t force_copy, uintptr_t external_storage, void (*iodone)(buf_t, void *), void *arg); + + +/*! + @function buf_shadow + @abstract returns true if 'bp' is a shadow of another buffer. + @param bp Buffer to query. + @return 1 if 'bp' is a shadow, 0 otherwise. +*/ +int buf_shadow(buf_t bp); + + +/*! + @function buf_alloc + @abstract Allocate an uninitialized buffer. + @discussion A buffer returned by buf_alloc() is marked as busy and as an iobuf; it has no storage set up and must be + set up using buf_setdataptr() or buf_setupl()/buf_map(). + @param vp vnode to associate with the buffer: optionally NULL. If vp is a device file, then + the buffer's associated device will be set. If vp is NULL, it can be set later with buf_setvnode(). + @return New buffer. + */ +buf_t buf_alloc(vnode_t); + +/*! + @function buf_free + @abstract Free a buffer that was allocated with buf_alloc(). + @discussion The storage (UPL, data pointer) associated with an iobuf must be freed manually. + @param bp The buffer to free. + @return void. + */ +void buf_free(buf_t); /* - * These flags are kept in b_flags. - */ -#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_DIRTY 0x00000100 /* Dirty page to be pushed out async. */ -#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_WASDIRTY 0x00001000 /* page was found dirty in the VM cache */ -#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_PAGEOUT 0x00010000 /* Page out indicator... */ -#define B_PGIN 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_TAPE 0x00200000 /* Magnetic tape I/O. */ -#define B_PAGELIST 0x00400000 /* Buffer describes pagelist I/O. */ -#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_HDRALLOC 0x02000000 /* zone allocated buffer header */ -#define B_NORELSE 0x04000000 /* don't brelse() in bwrite() */ -#define B_NEED_IODONE 0x08000000 - /* need to do a biodone on the */ - /* real_bp associated with a cluster_io */ -#define B_COMMIT_UPL 0x10000000 - /* commit pages in upl when */ - /* I/O completes/fails */ -#define B_ZALLOC 0x20000000 /* b_data is zalloc()ed */ -#define B_META 0x40000000 /* buffer contains meta-data. */ -#define B_VECTORLIST 0x80000000 /* Used by device drivers. */ + * flags for buf_invalidateblks + */ +#define BUF_WRITE_DATA 0x0001 /* write data blocks first */ +#define BUF_SKIP_META 0x0002 /* skip over metadata blocks */ +#define BUF_INVALIDATE_LOCKED 0x0004 /* force B_LOCKED blocks to be invalidated */ +/*! + @function buf_invalidateblks + @abstract Invalidate all the blocks associated with a vnode. + @discussion This function does for all blocks associated with a vnode what buf_invalblkno does for one block. + Again, it will only be able to invalidate data which were populated with traditional buffer cache routines, + i.e. by buf_getblk() and callers thereof. Unlike buf_invalblkno(), it can be made to write dirty data to disk + rather than casting it aside. + @param bp The buffer whose data to invalidate. + @param flags BUF_WRITE_DATA: write dirty data to disk with VNOP_BWRITE() before kicking buffer cache entries out. + BUF_SKIP_META: do not invalidate metadata blocks. + @param slpflag Flags to pass to "msleep" while waiting to acquire busy buffers. + @param slptimeo Timeout in "hz" (1/100 second) to wait for a buffer to become unbusy before waking from sleep + and re-starting the scan. + @return 0 for success, error values from msleep(). + */ +int buf_invalidateblks(vnode_t, int, int, int); /* - * Zero out the buffer's data area. + * flags for buf_flushdirtyblks and buf_iterate + */ +#define BUF_SKIP_NONLOCKED 0x01 +#define BUF_SKIP_LOCKED 0x02 +#define BUF_SCAN_CLEAN 0x04 /* scan the clean buffers */ +#define BUF_SCAN_DIRTY 0x08 /* scan the dirty buffers */ +#define BUF_NOTIFY_BUSY 0x10 /* notify the caller about the busy pages during the scan */ + + +#define BUF_RETURNED 0 +#define BUF_RETURNED_DONE 1 +#define BUF_CLAIMED 2 +#define BUF_CLAIMED_DONE 3 +/*! + @function buf_flushdirtyblks + @abstract Write dirty file blocks to disk. + @param vp The vnode whose blocks to flush. + @param wait Wait for writes to complete before returning. + @param flags Can pass zero, meaning "flush all dirty buffers." + BUF_SKIP_NONLOCKED: Skip buffers which are not busy when we encounter them. + BUF_SKIP_LOCKED: Skip buffers which are busy when we encounter them. + @param msg String to pass to msleep(). + @return void. + */ +void buf_flushdirtyblks(vnode_t, int, int, const char *); + +/*! + @function buf_iterate + @abstract Perform some operation on all buffers associated with a vnode. + @param vp The vnode whose buffers to scan. + @param callout Function to call on each buffer. Should return one of: + BUF_RETURNED: buf_iterate() should call buf_brelse() on the buffer. + BUF_RETURNED_DONE: buf_iterate() should call buf_brelse() on the buffer and then stop iterating. + BUF_CLAIMED: buf_iterate() should continue iterating (and not call buf_brelse()). + BUF_CLAIMED_DONE: buf_iterate() should stop iterating (and not call buf_brelse()). + @param flag + BUF_SKIP_NONLOCKED: Skip buffers which are not busy when we encounter them. BUF_SKIP_LOCKED: Skip buffers which are busy when we encounter them. + BUF_SCAN_CLEAN: Call out on clean buffers. + BUF_SCAN_DIRTY: Call out on dirty buffers. + BUF_NOTIFY_BUSY: If a buffer cannot be acquired, pass a NULL buffer to callout; otherwise, + that buffer will be silently skipped. + @param arg Argument to pass to callout in addition to buffer. + @return void. + */ +void buf_iterate(vnode_t, int (*)(buf_t, void *), int, void *); + +/*! + @function buf_clear + @abstract Zero out the storage associated with a buffer. + @discussion Calls buf_map() to get the buffer's data address; for a B_CLUSTER + buffer (one which has had buf_setupl() called on it), it tries to map the buffer's + UPL into memory; should only be called once during the life cycle of an iobuf (one allocated + with buf_alloc()). + @param bp The buffer to zero out. + @return void. + */ +void buf_clear(buf_t); + +/*! + @function buf_bawrite + @abstract Start an asychronous write on a buffer. + @discussion Calls VNOP_BWRITE to start the process of propagating an asynchronous write down to the device layer. + Callers can wait for writes to complete at their discretion using buf_biowait(). When this function is called, + data should already have been written to the buffer's data region. + @param bp The buffer on which to initiate I/O. + @param throttle If "throttle" is nonzero and more than VNODE_ASYNC_THROTTLE writes are in progress on this file, + buf_bawrite() will block until the write count drops below VNODE_ASYNC_THROTTLE. If "throttle" is zero and the write + count is high, it will fail with EWOULDBLOCK; the caller can decide whether to make a blocking call or pursue + other opportunities. + @return EWOULDBLOCK if write count is high and "throttle" is zero; otherwise, errors from VNOP_BWRITE. + */ +errno_t buf_bawrite(buf_t); + +/*! + @function buf_bdwrite + @abstract Mark a buffer for delayed write. + @discussion Marks a buffer as waiting for delayed write and the current I/O as complete; data will be written to backing store + before the buffer is reused, but it will not be queued for I/O immediately. Note that for buffers allocated + with buf_alloc(), there are no such guarantees; you must take care of your own flushing to disk. If + the number of delayed writes pending on the system is greater than an internal limit and the caller has not + requested otherwise [see return_error] , buf_bdwrite() will unilaterally launch an asynchronous I/O with buf_bawrite() to keep the pile of + delayed writes from getting too large. + @param bp The buffer to mark for delayed write. + @param return_error If the number of pending delayed writes systemwide is larger than an internal limit, + return EAGAIN rather than doing an asynchronous write. + @return EAGAIN for return_error != 0 case, 0 for succeess, errors from buf_bawrite. + */ +errno_t buf_bdwrite(buf_t); + +/*! + @function buf_bwrite + @abstract Write a buffer's data to backing store. + @discussion Once the data in a buffer has been modified, buf_bwrite() starts sending it to disk by calling + VNOP_STRATEGY. Unless B_ASYNC has been set on the buffer (by buf_setflags() or otherwise), data will have + been written to disk when buf_bwrite() returns. See Bach (p 56). + @param bp The buffer to write to disk. + @return 0 for success; errors from buf_biowait(). + */ +errno_t buf_bwrite(buf_t); + +/*! + @function buf_biodone + @abstract Mark an I/O as completed. + @discussion buf_biodone() should be called by whosoever decides that an I/O on a buffer is complete; for example, + IOStorageFamily. It clears the dirty flag on a buffer and signals on the vnode that a write has completed + with vnode_writedone(). If a callout or filter has been set on the buffer, that function is called. In the case + of a callout, that function is expected to take care of cleaning up and freeing the buffer. + Otherwise, if the buffer is marked B_ASYNC (e.g. it was passed to buf_bawrite()), then buf_biodone() + considers itself justified in calling buf_brelse() to return it to free lists--no one is waiting for it. Finally, + waiters on the bp (e.g. in buf_biowait()) are woken up. + @param bp The buffer to mark as done with I/O. + @return void. + */ +void buf_biodone(buf_t); + +/*! + @function buf_biowait + @abstract Wait for I/O on a buffer to complete. + @discussion Waits for I/O on a buffer to finish, as marked by a buf_biodone() call. + @param bp The buffer to wait on. + @return 0 for a successful wait; nonzero the buffer has been marked as EINTR or had an error set on it. + */ +errno_t buf_biowait(buf_t); + +/*! + @function buf_brelse + @abstract Release any claim to a buffer, sending it back to free lists. + @discussion buf_brelse() cleans up buffer state and releases a buffer to the free lists. If the buffer + is not marked invalid and its pages are dirty (e.g. a delayed write was made), its data will be commited + to backing store. If it is marked invalid, its data will be discarded completely. + A valid, cacheable buffer will be put on a list and kept in the buffer hash so it + can be found again; otherwise, it will be dissociated from its vnode and treated as empty. Which list a valid + buffer is placed on depends on the use of buf_markaged(), whether it is metadata, and the B_LOCKED flag. A + B_LOCKED buffer will not be available for reuse by other files, though its data may be paged out. + Note that buf_brelse() is intended for use with traditionally allocated buffers. + @param bp The buffer to release. + @retrn void. + */ +void buf_brelse(buf_t); + +/*! + @function buf_bread + @abstract Synchronously read a block of a file. + @discussion buf_bread() is the traditional way to read a single logical block of a file through the buffer cache. + It tries to find the buffer and corresponding page(s) in core, calls VNOP_STRATEGY if necessary to bring the data + into memory, and waits for I/O to complete. It should not be used to read blocks of greater than 4K (one VM page) + in size; use cluster routines for large reads. Indeed, the cluster layer is a more efficient choice for reading DATA + unless you need some finely-tuned semantics that it cannot provide. + @param vp The file from which to read. + @param blkno The logical (filesystem) block number to read. + @param size Size of block; do not use for sizes > 4K. + @param cred Credential to store and use for reading from disk if data are not already in core. + @param bpp Destination pointer for buffer. + @return 0 for success, or an error from buf_biowait(). + */ +errno_t buf_bread(vnode_t, daddr64_t, int, kauth_cred_t, buf_t *); + +/*! + @function buf_breadn + @abstract Read a block from a file with read-ahead. + @discussion buf_breadn() reads one block synchronously in the style of buf_bread() and fires + off a specified set of asynchronous reads to improve the likelihood of future cache hits. + It should not be used to read blocks of greater than 4K (one VM page) in size; use cluster + routines for large reads. Indeed, the cluster layer is a more efficient choice for reading DATA + unless you need some finely-tuned semantics that it cannot provide. + @param vp The file from which to read. + @param blkno The logical (filesystem) block number to read synchronously. + @param size Size of block; do not use for sizes > 4K. + @param rablks Array of logical block numbers for asynchronous read-aheads. + @param rasizes Array of block sizes for asynchronous read-aheads, each index corresponding to same index in "rablks." + @param nrablks Number of entries in read-ahead arrays. + @param cred Credential to store and use for reading from disk if data are not already in core. + @param bpp Destination pointer for buffer. + @return 0 for success, or an error from buf_biowait(). + */ +errno_t buf_breadn(vnode_t, daddr64_t, int, daddr64_t *, int *, int, kauth_cred_t, buf_t *); + +/*! + @function buf_meta_bread + @abstract Synchronously read a metadata block of a file. + @discussion buf_meta_bread() is the traditional way to read a single logical block of a file through the buffer cache. + It tries to find the buffer and corresponding page(s) in core, calls VNOP_STRATEGY if necessary to bring the data + into memory, and waits for I/O to complete. It should not be used to read blocks of greater than 4K (one VM page) + in size; use cluster routines for large reads. Reading meta-data through the traditional buffer cache, unlike + reading data, is efficient and encouraged, especially if the blocks being read are significantly smaller than page size. + @param vp The file from which to read. + @param blkno The logical (filesystem) block number to read. + @param size Size of block; do not use for sizes > 4K. + @param cred Credential to store and use for reading from disk if data are not already in core. + @param bpp Destination pointer for buffer. + @return 0 for success, or an error from buf_biowait(). */ -#define clrbuf(bp) { \ - bzero((bp)->b_data, (u_int)(bp)->b_bcount); \ - (bp)->b_resid = 0; \ -} +errno_t buf_meta_bread(vnode_t, daddr64_t, int, kauth_cred_t, buf_t *); + +/*! + @function buf_meta_breadn + @abstract Read a metadata block from a file with read-ahead. + @discussion buf_meta_breadn() reads one block synchronously in the style of buf_meta_bread() and fires + off a specified set of asynchronous reads to improve the likelihood of future cache hits. + It should not be used to read blocks of greater than 4K (one VM page) in size; use cluster + routines for large reads. + @param vp The file from which to read. + @param blkno The logical (filesystem) block number to read synchronously. + @param size Size of block; do not use for sizes > 4K. + @param rablks Array of logical block numbers for asynchronous read-aheads. + @param rasizes Array of block sizes for asynchronous read-aheads, each index corresponding to same index in "rablks." + @param nrablks Number of entries in read-ahead arrays. + @param cred Credential to store and use for reading from disk if data are not already in core. + @param bpp Destination pointer for buffer. + @return 0 for success, or an error from buf_biowait(). + */ +errno_t buf_meta_breadn(vnode_t, daddr64_t, int, daddr64_t *, int *, int, kauth_cred_t, buf_t *); + +/*! + @function minphys + @abstract Adjust a buffer's count to be no more than maximum physical I/O transfer size for the host architecture. + @discussion physio() takes as a parameter a function to bound transfer sizes for each VNOP_STRATEGY() call. minphys() + is a default implementation. It calls buf_setcount() to make the buffer's count the min() of its current count + and the max I/O size for the host architecture. + @param bp The buffer whose byte count to modify. + @return New byte count. + */ +u_int minphys(buf_t bp); + +/*! + @function physio + @abstract Perform I/O on a device to/from target memory described by a uio. + @discussion physio() allows I/O directly from a device to user-space memory. It waits + for all I/O to complete before returning. + @param f_strategy Strategy routine to call to initiate I/O. + @param bp Buffer to configure and pass to strategy routine; can be NULL. + @param dev Device on which to perform I/O. + @param flags B_READ or B_WRITE. + @param f_minphys Function which calls buf_setcount() to set a byte count which is suitably + small for the device in question. Returns byte count that has been set (or unchanged) on the buffer. + @param uio UIO describing the I/O operation. + @param blocksize Logical block size for this vnode. + @return 0 for success; EFAULT for an invalid uio; errors from buf_biowait(). + */ +int physio(void (*)(buf_t), buf_t, dev_t, int , u_int (*)(buf_t), struct uio *, int ); -/* 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 */ -/* Flags for operation type in getblk() */ +/* + * Flags for operation type in getblk() + */ #define BLK_READ 0x01 /* buffer for read */ #define BLK_WRITE 0x02 /* buffer for write */ -#define BLK_PAGEIN 0x04 /* buffer for pagein */ -#define BLK_PAGEOUT 0x08 /* buffer for pageout */ #define BLK_META 0x10 /* buffer for metadata */ -#define BLK_CLREAD 0x20 /* buffer for cluster read */ -#define BLK_CLWRITE 0x40 /* buffer for cluster write */ +/* + * modifier for above flags... if set, getblk will only return + * a bp that is already valid... i.e. found in the cache + */ +#define BLK_ONLYVALID 0x80000000 + +/*! + @function buf_getblk + @abstract Traditional buffer cache routine to get a buffer corresponding to a logical block in a file. + @discussion buf_getblk() gets a buffer, not necessarily containing valid data, representing a block in a file. + A metadata buffer will be returned with its own zone-allocated storage, managed by the traditional buffer-cache + layer, whereas data buffers will be returned hooked into backing by the UBC (which in fact controls the caching of data). + buf_getblk() first looks for the buffer header in cache; if the buffer is in-core but busy, buf_getblk() will wait for it to become + unbusy, depending on the slpflag and slptimeo parameters. If the buffer is found unbusy and is a metadata buffer, + it must already contain valid data and will be returned directly; data buffers will have a UPL configured to + prepare for interaction with the underlying UBC. If the buffer is found in core, it will be marked as such + and buf_fromcache() will return truth. A buffer is allocated and initialized (but not filled with data) + if none is found in core. buf_bread(), buf_breadn(), buf_meta_bread(), and buf_meta_breadn() all + return buffers obtained with buf_getblk(). + @param vp File for which to get block. + @param blkno Logical block number. + @param size Size of block. + @param slpflag Flag to pass to msleep() while waiting for buffer to become unbusy. + @param slptimeo Time, in milliseconds, to wait for buffer to become unbusy. 0 means to wait indefinitely. + @param operation BLK_READ: want a read buffer. BLK_WRITE: want a write buffer. BLK_META: want a metadata buffer. BLK_ONLYVALID: + only return buffers which are found in core (do not allocate anew), and do not change buffer size. The last remark means + that if a given logical block is found in core with a different size than what is requested, the buffer size will not be modified. + @return Buffer found in core or newly allocated, either containing valid data or ready for I/O. + */ +buf_t buf_getblk(vnode_t, daddr64_t, int, int, int, int); -extern int nbuf; /* The number of buffer headers */ -extern struct buf *buf; /* The buffer headers. */ +/*! + @function buf_geteblk + @abstract Get a metadata buffer which is marked invalid and not associated with any vnode. + @discussion A buffer is returned with zone-allocated storage of the specified size, marked B_META and invalid. + It has no vnode and is not visible in the buffer hash. + @param size Size of buffer. + @return Always returns a new buffer. + */ +buf_t buf_geteblk(int); -#endif /* __APPLE_API_PRIVATE */ +/*! + @function buf_clear_redundancy_flags + @abstract Clear flags on a buffer. + @discussion: buffer_redundancy_flags &= ~flags + @param bp Buffer whose flags to clear. + @param flags Flags to remove from buffer's mask + @return void. + */ +void buf_clear_redundancy_flags(buf_t, uint32_t); +/*! + @function buf_redundancyflags + @abstract Get redundancy flags set on a buffer. + @param bp Buffer whose redundancy flags to grab. + @return flags. + */ +uint32_t buf_redundancy_flags(buf_t); -#ifdef __APPLE_API_UNSTABLE -/* Macros to clear/set/test flags. */ -#define SET(t, f) (t) |= (f) -#define CLR(t, f) (t) &= ~(f) -#define ISSET(t, f) ((t) & (f)) -#endif /* __APPLE_API_UNSTABLE */ +/*! + @function buf_setredundancyflags + @abstract Set redundancy flags on a buffer. + @discussion: buffer_redundancy_flags |= flags + @param bp Buffer whose flags to set. + @param flags Flags to add to buffer's redundancy flags + @return void. + */ +void buf_set_redundancy_flags(buf_t, uint32_t); -#ifdef __APPLE_API_PRIVATE -/* - * Definitions for the buffer free lists. +#ifdef KERNEL_PRIVATE +void buf_setfilter(buf_t, void (*)(buf_t, void *), void *, void (**)(buf_t, void *), void **); + + +/*! + @function buf_getcpaddr + @abstract Set the address of cp_entry on a buffer. + @param bp Buffer whose cp entry value has to be set + @return void. */ -#define BQUEUES 6 /* number of free buffer queues */ +void buf_setcpaddr(buf_t, void *); + +/*! + @function buf_getcpaddr + @abstract Get the address of cp_entry on a buffer. + @param bp Buffer whose error value to set. + @return int. + */ +void *buf_getcpaddr(buf_t); +#endif /* KERNEL_PRIVATE */ -#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 */ -#endif /* __APPLE_API_PRIVATE */ -__BEGIN_DECLS -#ifdef __APPLE_API_UNSTABLE -int allocbuf __P((struct buf *, int)); -void bawrite __P((struct buf *)); -void bdwrite __P((struct buf *)); -void biodone __P((struct buf *)); -int biowait __P((struct buf *)); -int bread __P((struct vnode *, daddr_t, int, - struct ucred *, struct buf **)); -int meta_bread __P((struct vnode *, daddr_t, int, - struct ucred *, struct buf **)); -int breada __P((struct vnode *, daddr_t, int, daddr_t, int, - struct ucred *, struct buf **)); -int breadn __P((struct vnode *, daddr_t, int, daddr_t *, int *, int, - struct ucred *, struct buf **)); -int meta_breadn __P((struct vnode *, daddr_t, int, daddr_t *, int *, int, - struct ucred *, struct buf **)); -void brelse __P((struct buf *)); -void bremfree __P((struct buf *)); -void bufinit __P((void)); -void bwillwrite __P((void)); -int bwrite __P((struct buf *)); -struct buf *getblk __P((struct vnode *, daddr_t, int, int, int, int)); -struct buf *geteblk __P((int)); -struct buf *incore __P((struct vnode *, daddr_t)); -u_int minphys __P((struct buf *bp)); -int physio __P((void (*)(struct buf *), struct buf *, dev_t, int , u_int (*)(struct buf *), struct uio *, int )); -int count_busy_buffers __P((void)); -struct buf *alloc_io_buf __P((struct vnode *, int)); -void free_io_buf __P((struct buf *)); -void reassignbuf __P((struct buf *, struct vnode *)); -#endif /* __APPLE_API_UNSTABLE */ __END_DECLS -#ifdef __APPLE_API_PRIVATE -/* - * 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 /* __APPLE_API_PRIVATE */ - -#endif /* KERNEL */ + +/* Macros to clear/set/test flags. */ +#define SET(t, f) (t) |= (f) +#define CLR(t, f) (t) &= ~(f) +#define ISSET(t, f) ((t) & (f)) + + #endif /* !_SYS_BUF_H_ */