/* * Copyright (c) 2000-2016 Apple Computer, 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_H_ #define _SYS_BUF_H_ #include <sys/cdefs.h> #include <sys/kernel_types.h> #include <sys/ucred.h> #include <mach/memory_object_types.h> #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 (deprecated) */ #define B_ENCRYPTED_IO 0x00004000 /* Encrypted I/O */ #define B_STATICCONTENT 0x00008000 /* Buffer is likely to remain unaltered */ /* * make sure to check when adding flags that * that the new flags don't overlap the definitions * in buf_internal.h */ __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 bp); /*! * @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. */ void buf_markinvalid(buf_t bp); /*! * @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 bp); void buf_markclean(buf_t); /*! * @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. */ void buf_markeintr(buf_t bp); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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. */ void buf_setdirtyoff(buf_t bp, 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. */ void buf_setdirtyend(buf_t bp, 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 bp); /*! * @function buf_seterror * @abstract Set an error value on a buffer. * @param bp Buffer whose error value to set. */ void buf_seterror(buf_t bp, 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 */ void buf_setflags(buf_t bp, int32_t flags); /*! * @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 */ void buf_clearflags(buf_t bp, int32_t flags); /*! * @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 bp); /*! * @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. */ void buf_reset(buf_t bp, int32_t flags); /*! * @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 bp, caddr_t *io_addr); /*! * @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. * @return 0 for success, EINVAL if unable to unmap buffer. */ errno_t buf_unmap(buf_t bp); /*! * @function buf_setdrvdata * @abstract Set driver-specific data on a buffer. * @param bp Buffer whose driver-data to set. * @param drvdata Opaque driver data. */ void buf_setdrvdata(buf_t bp, void *drvdata); /*! * @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 bp); /*! * @function buf_setfsprivate * @abstract Set filesystem-specific data on a buffer. * @param bp Buffer whose filesystem data to set. * @param fsprivate Opaque filesystem data. */ void buf_setfsprivate(buf_t bp, void *fsprivate); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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. */ void buf_setblkno(buf_t bp, daddr64_t blkno); /*! * @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. */ void buf_setlblkno(buf_t bp, daddr64_t lblkno); /*! * @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 bp); /*! * @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 bp); /*! * @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 bp); /*! * @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. */ void buf_setcount(buf_t bp, uint32_t bcount); /*! * @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. */ void buf_setsize(buf_t bp, 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. */ void buf_setresid(buf_t bp, uint32_t resid); /*! * @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. */ void buf_setdataptr(buf_t bp, uintptr_t data); /*! * @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 bp); /*! * @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 bp); /*! * @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. */ void buf_setvnode(buf_t bp, vnode_t vp); /*! * @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 bp); /*! * @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 bp, vnode_t vp); /*! * @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 devvp, void *ap); /* * 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 vp vnode 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 vp, daddr64_t lblkno, int flags); /*! * @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 bp); /*! * @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 bp, void (*callback)(buf_t, void *), void *transaction); /*! * @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. * @param 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 bp, upl_t upl, uint32_t offset); /*! * @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 bp, int io_offset, int io_size, void (*iodone)(buf_t, void *), void *arg); /*! * @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 vp); /*! * @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. */ void buf_free(buf_t bp); /* * 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 vp The vnode 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 vp, int flags, int slpflag, int slptimeo); /* * 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(). */ void buf_flushdirtyblks(vnode_t vp, int wait, int flags, const char *msg); /*! * @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 flags * 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. */ void buf_iterate(vnode_t vp, int (*callout)(buf_t, void *), int flags, void *arg); /*! * @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. */ void buf_clear(buf_t bp); /*! * @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. * @return EWOULDBLOCK if write count is high and "throttle" is zero; otherwise, errors from VNOP_BWRITE. */ errno_t buf_bawrite(buf_t bp); /*! * @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. * @return EAGAIN for return_error != 0 case, 0 for succeess, errors from buf_bawrite. */ errno_t buf_bdwrite(buf_t bp); /*! * @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 bp); /*! * @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. */ void buf_biodone(buf_t bp); /*! * @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 bp); /*! * @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. */ void buf_brelse(buf_t bp); /*! * @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 vp, daddr64_t blkno, int size, kauth_cred_t cred, buf_t *bpp); /*! * @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 vp, daddr64_t blkno, int size, daddr64_t *rablks, int *rasizes, int nrablks, kauth_cred_t cred, buf_t *bpp); /*! * @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(). */ errno_t buf_meta_bread(vnode_t vp, daddr64_t blkno, int size, kauth_cred_t cred, buf_t *bpp); /*! * @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 vp, daddr64_t blkno, int size, daddr64_t *rablks, int *rasizes, int nrablks, kauth_cred_t cred, buf_t *bpp); /*! * @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 (*f_strategy)(buf_t), buf_t bp, dev_t dev, int flags, u_int (*f_minphys)(buf_t), struct uio *uio, int blocksize); /* * Flags for operation type in getblk() */ #define BLK_READ 0x01 /* buffer for read */ #define BLK_WRITE 0x02 /* buffer for write */ #define BLK_META 0x10 /* buffer for metadata */ /* * 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 vp, daddr64_t blkno, int size, int slpflag, int slptimeo, int operation); /*! * @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 size); /*! * @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 */ void buf_clear_redundancy_flags(buf_t bp, uint32_t flags); /*! * @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 bp); /*! * @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 */ void buf_set_redundancy_flags(buf_t bp, uint32_t flags); /*! * @function buf_attr * @abstract Gets the attributes for this buf. * @param bp Buffer whose attributes to get. * @return bufattr_t. */ bufattr_t buf_attr(buf_t bp); /*! * @function buf_markstatic * @abstract Mark a buffer as being likely to contain static data. * @param bp Buffer to mark. */ void buf_markstatic(buf_t bp); /*! * @function buf_static * @abstract Check if a buffer contains static data. * @param bp Buffer to test. * @return Nonzero if buffer has static data, 0 otherwise. */ int buf_static(buf_t bp); /*! * @function bufattr_markiosched * @abstract Mark a buffer as belonging to an io scheduled mount point * @param bap Buffer attributes to mark. * @discussion Marks the buffer so that spec_strategy() will know that it belongs to an io scheduled mount point */ void bufattr_markioscheduled(bufattr_t bap); /*! * @function bufattr_iosched * @abstract Check if a buffer is marked as io scheduled * @param bap Buffer attributes to test. * @return Nonzero if the buffer is marked io scheduled, 0 otherwise. */ int bufattr_ioscheduled(bufattr_t bap); #ifdef KERNEL_PRIVATE void buf_setfilter(buf_t, void (*)(buf_t, void *), void *, void(**)(buf_t, void *), void **); /* bufattr allocation/duplication/deallocation functions */ bufattr_t bufattr_alloc(void); bufattr_t bufattr_dup(bufattr_t bap); void bufattr_free(bufattr_t bap); /*! * @function bufattr_cpx * @abstract Returns a pointer to a cpx_t structure. * @param bap Buffer Attribute whose cpx_t structure you wish to get. * @return Returns a cpx_t structure, or NULL if not valid */ struct cpx *bufattr_cpx(bufattr_t bap); /*! * @function bufattr_setcpx * @abstract Set the cp_ctx on a buffer attribute. * @param bap Buffer Attribute that you wish to change */ void bufattr_setcpx(bufattr_t bap, struct cpx *cpx); /*! * @function bufattr_cpoff * @abstract Gets the file offset on the buffer. * @param bap Buffer Attribute whose file offset value is used */ uint64_t bufattr_cpoff(bufattr_t bap); /*! * @function bufattr_setcpoff * @abstract Set the file offset for a content protected I/O on * a buffer attribute. * @param bap Buffer Attribute whose cp file offset has to be set */ void bufattr_setcpoff(bufattr_t bap, uint64_t); /*! * @function bufattr_rawencrypted * @abstract Check if a buffer contains raw encrypted data. * @param bap Buffer attribute to test. * @return Nonzero if buffer has raw encrypted data, 0 otherwise. */ int bufattr_rawencrypted(bufattr_t bap); /*! * @function bufattr_markgreedymode * @abstract Mark a buffer to use the greedy mode for writing. * @param bap Buffer attributes to mark. * @discussion Greedy Mode: request improved write performance from the underlying device at the expense of storage efficiency */ void bufattr_markgreedymode(bufattr_t bap); /*! * @function bufattr_greedymode * @abstract Check if a buffer is written using the Greedy Mode * @param bap Buffer attributes to test. * @discussion Greedy Mode: request improved write performance from the underlying device at the expense of storage efficiency * @return Nonzero if buffer uses greedy mode, 0 otherwise. */ int bufattr_greedymode(bufattr_t bap); /*! * @function bufattr_markisochronous * @abstract Mark a buffer to use the isochronous throughput mode for writing. * @param bap Buffer attributes to mark. * @discussion isochronous mode: request improved write performance from the underlying device at the expense of storage efficiency */ void bufattr_markisochronous(bufattr_t bap); /*! * @function bufattr_isochronous * @abstract Check if a buffer is written using the isochronous * @param bap Buffer attributes to test. * @discussion isochronous mode: request improved write performance from the underlying device at the expense of storage efficiency * @return Nonzero if buffer uses isochronous mode, 0 otherwise. */ int bufattr_isochronous(bufattr_t bap); /*! * @function bufattr_throttled * @abstract Check if a buffer is throttled. * @param bap Buffer attribute to test. * @return Nonzero if the buffer is throttled, 0 otherwise. */ int bufattr_throttled(bufattr_t bap); /*! * @function bufattr_passive * @abstract Check if a buffer is marked passive. * @param bap Buffer attribute to test. * @return Nonzero if the buffer is marked passive, 0 otherwise. */ int bufattr_passive(bufattr_t bap); /*! * @function bufattr_nocache * @abstract Check if a buffer has nocache attribute. * @param bap Buffer attribute to test. * @return Nonzero if the buffer is not cached, 0 otherwise. */ int bufattr_nocache(bufattr_t bap); /*! * @function bufattr_meta * @abstract Check if a buffer has the bufattr meta attribute. * @param bap Buffer attribute to test. * @return Nonzero if the buffer has meta attribute, 0 otherwise. */ int bufattr_meta(bufattr_t bap); /*! * @function bufattr_markmeta * @abstract Set the bufattr meta attribute. * @param bap Buffer attribute to manipulate. */ void bufattr_markmeta(bufattr_t bap); /*! * @function bufattr_delayidlesleep * @abstract Check if a buffer is marked to delay idle sleep on disk IO. * @param bap Buffer attribute to test. * @return Nonzero if the buffer is marked to delay idle sleep on disk IO, 0 otherwise. */ int bufattr_delayidlesleep(bufattr_t bap); /*! * @function buf_kernel_addrperm_addr * @abstract Obfuscate the buf pointers. * @param addr Buf_t pointer. * @return Obfuscated pointer if addr is non zero, 0 otherwise. */ vm_offset_t buf_kernel_addrperm_addr(void * addr); /*! * @function bufattr_markquickcomplete * @abstract Mark a buffer to hint quick completion to the driver. * @discussion This flag hints the storage driver that some thread is waiting for this I/O to complete. * It should therefore attempt to complete it as soon as possible at the cost of device efficiency. * @param bap Buffer attributes to mark. */ void bufattr_markquickcomplete(bufattr_t bap); /*! * @function bufattr_quickcomplete * @abstract Check if a buffer is marked for quick completion * @discussion This flag hints the storage driver that some thread is waiting for this I/O to complete. * It should therefore attempt to complete it as soon as possible at the cost of device efficiency. * @param bap Buffer attribute to test. * @return Nonzero if the buffer is marked for quick completion, 0 otherwise. */ int bufattr_quickcomplete(bufattr_t bap); int count_lock_queue(void); /* * 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 */ errno_t buf_acquire(buf_t, int, int, int); buf_t buf_create_shadow_priv(buf_t bp, boolean_t force_copy, uintptr_t external_storage, void (*iodone)(buf_t, void *), void *arg); void buf_drop(buf_t); #endif /* KERNEL_PRIVATE */ __END_DECLS /* 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_ */