 a9add83e5a
			
		
	
	
	a9add83e5a
	
	
	
		
			
			Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
		
			
				
	
	
		
			297 lines
		
	
	
	
		
			10 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			297 lines
		
	
	
	
		
			10 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
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|  * All Rights Reserved.
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|  *
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|  * This program is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU General Public License as
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|  * published by the Free Software Foundation.
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|  *
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|  * This program is distributed in the hope that it would be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program; if not, write the Free Software Foundation,
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|  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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|  */
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| #ifndef __XFS_BUF_H__
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| #define __XFS_BUF_H__
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| 
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| #include <linux/list.h>
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| #include <linux/types.h>
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| #include <linux/spinlock.h>
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| #include <asm/system.h>
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| #include <linux/mm.h>
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| #include <linux/fs.h>
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| #include <linux/buffer_head.h>
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| #include <linux/uio.h>
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| 
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| /*
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|  *	Base types
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|  */
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| 
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| #define XFS_BUF_DADDR_NULL	((xfs_daddr_t) (-1LL))
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| 
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| #define xfs_buf_ctob(pp)	((pp) * PAGE_CACHE_SIZE)
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| #define xfs_buf_btoc(dd)	(((dd) + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT)
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| #define xfs_buf_btoct(dd)	((dd) >> PAGE_CACHE_SHIFT)
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| #define xfs_buf_poff(aa)	((aa) & ~PAGE_CACHE_MASK)
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| 
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| typedef enum {
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| 	XBRW_READ = 1,			/* transfer into target memory */
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| 	XBRW_WRITE = 2,			/* transfer from target memory */
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| 	XBRW_ZERO = 3,			/* Zero target memory */
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| } xfs_buf_rw_t;
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| 
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| #define XBF_READ	(1 << 0) /* buffer intended for reading from device */
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| #define XBF_WRITE	(1 << 1) /* buffer intended for writing to device */
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| #define XBF_READ_AHEAD	(1 << 2) /* asynchronous read-ahead */
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| #define XBF_MAPPED	(1 << 3) /* buffer mapped (b_addr valid) */
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| #define XBF_ASYNC	(1 << 4) /* initiator will not wait for completion */
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| #define XBF_DONE	(1 << 5) /* all pages in the buffer uptodate */
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| #define XBF_DELWRI	(1 << 6) /* buffer has dirty pages */
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| #define XBF_STALE	(1 << 7) /* buffer has been staled, do not find it */
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| 
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| /* I/O hints for the BIO layer */
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| #define XBF_SYNCIO	(1 << 10)/* treat this buffer as synchronous I/O */
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| #define XBF_FUA		(1 << 11)/* force cache write through mode */
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| #define XBF_FLUSH	(1 << 12)/* flush the disk cache before a write */
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| 
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| /* flags used only as arguments to access routines */
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| #define XBF_LOCK	(1 << 15)/* lock requested */
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| #define XBF_TRYLOCK	(1 << 16)/* lock requested, but do not wait */
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| #define XBF_DONT_BLOCK	(1 << 17)/* do not block in current thread */
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| 
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| /* flags used only internally */
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| #define _XBF_PAGES	(1 << 20)/* backed by refcounted pages */
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| #define _XBF_KMEM	(1 << 21)/* backed by heap memory */
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| #define _XBF_DELWRI_Q	(1 << 22)/* buffer on delwri queue */
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| 
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| typedef unsigned int xfs_buf_flags_t;
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| 
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| #define XFS_BUF_FLAGS \
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| 	{ XBF_READ,		"READ" }, \
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| 	{ XBF_WRITE,		"WRITE" }, \
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| 	{ XBF_READ_AHEAD,	"READ_AHEAD" }, \
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| 	{ XBF_MAPPED,		"MAPPED" }, \
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| 	{ XBF_ASYNC,		"ASYNC" }, \
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| 	{ XBF_DONE,		"DONE" }, \
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| 	{ XBF_DELWRI,		"DELWRI" }, \
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| 	{ XBF_STALE,		"STALE" }, \
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| 	{ XBF_SYNCIO,		"SYNCIO" }, \
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| 	{ XBF_FUA,		"FUA" }, \
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| 	{ XBF_FLUSH,		"FLUSH" }, \
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| 	{ XBF_LOCK,		"LOCK" },  	/* should never be set */\
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| 	{ XBF_TRYLOCK,		"TRYLOCK" }, 	/* ditto */\
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| 	{ XBF_DONT_BLOCK,	"DONT_BLOCK" },	/* ditto */\
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| 	{ _XBF_PAGES,		"PAGES" }, \
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| 	{ _XBF_KMEM,		"KMEM" }, \
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| 	{ _XBF_DELWRI_Q,	"DELWRI_Q" }
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| 
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| typedef enum {
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| 	XBT_FORCE_SLEEP = 0,
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| 	XBT_FORCE_FLUSH = 1,
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| } xfs_buftarg_flags_t;
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| 
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| typedef struct xfs_buftarg {
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| 	dev_t			bt_dev;
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| 	struct block_device	*bt_bdev;
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| 	struct backing_dev_info	*bt_bdi;
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| 	struct xfs_mount	*bt_mount;
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| 	unsigned int		bt_bsize;
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| 	unsigned int		bt_sshift;
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| 	size_t			bt_smask;
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| 
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| 	/* per device delwri queue */
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| 	struct task_struct	*bt_task;
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| 	struct list_head	bt_delwri_queue;
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| 	spinlock_t		bt_delwri_lock;
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| 	unsigned long		bt_flags;
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| 
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| 	/* LRU control structures */
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| 	struct shrinker		bt_shrinker;
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| 	struct list_head	bt_lru;
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| 	spinlock_t		bt_lru_lock;
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| 	unsigned int		bt_lru_nr;
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| } xfs_buftarg_t;
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| 
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| struct xfs_buf;
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| typedef void (*xfs_buf_iodone_t)(struct xfs_buf *);
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| 
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| #define XB_PAGES	2
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| 
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| typedef struct xfs_buf {
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| 	/*
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| 	 * first cacheline holds all the fields needed for an uncontended cache
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| 	 * hit to be fully processed. The semaphore straddles the cacheline
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| 	 * boundary, but the counter and lock sits on the first cacheline,
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| 	 * which is the only bit that is touched if we hit the semaphore
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| 	 * fast-path on locking.
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| 	 */
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| 	struct rb_node		b_rbnode;	/* rbtree node */
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| 	xfs_off_t		b_file_offset;	/* offset in file */
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| 	size_t			b_buffer_length;/* size of buffer in bytes */
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| 	atomic_t		b_hold;		/* reference count */
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| 	atomic_t		b_lru_ref;	/* lru reclaim ref count */
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| 	xfs_buf_flags_t		b_flags;	/* status flags */
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| 	struct semaphore	b_sema;		/* semaphore for lockables */
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| 
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| 	struct list_head	b_lru;		/* lru list */
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| 	wait_queue_head_t	b_waiters;	/* unpin waiters */
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| 	struct list_head	b_list;
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| 	struct xfs_perag	*b_pag;		/* contains rbtree root */
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| 	xfs_buftarg_t		*b_target;	/* buffer target (device) */
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| 	xfs_daddr_t		b_bn;		/* block number for I/O */
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| 	size_t			b_count_desired;/* desired transfer size */
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| 	void			*b_addr;	/* virtual address of buffer */
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| 	struct work_struct	b_iodone_work;
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| 	xfs_buf_iodone_t	b_iodone;	/* I/O completion function */
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| 	struct completion	b_iowait;	/* queue for I/O waiters */
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| 	void			*b_fspriv;
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| 	struct xfs_trans	*b_transp;
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| 	struct page		**b_pages;	/* array of page pointers */
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| 	struct page		*b_page_array[XB_PAGES]; /* inline pages */
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| 	unsigned long		b_queuetime;	/* time buffer was queued */
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| 	atomic_t		b_pin_count;	/* pin count */
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| 	atomic_t		b_io_remaining;	/* #outstanding I/O requests */
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| 	unsigned int		b_page_count;	/* size of page array */
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| 	unsigned int		b_offset;	/* page offset in first page */
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| 	unsigned short		b_error;	/* error code on I/O */
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| #ifdef XFS_BUF_LOCK_TRACKING
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| 	int			b_last_holder;
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| #endif
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| } xfs_buf_t;
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| 
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| 
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| /* Finding and Reading Buffers */
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| extern xfs_buf_t *_xfs_buf_find(xfs_buftarg_t *, xfs_off_t, size_t,
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| 				xfs_buf_flags_t, xfs_buf_t *);
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| #define xfs_incore(buftarg,blkno,len,lockit) \
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| 	_xfs_buf_find(buftarg, blkno ,len, lockit, NULL)
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| 
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| extern xfs_buf_t *xfs_buf_get(xfs_buftarg_t *, xfs_off_t, size_t,
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| 				xfs_buf_flags_t);
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| extern xfs_buf_t *xfs_buf_read(xfs_buftarg_t *, xfs_off_t, size_t,
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| 				xfs_buf_flags_t);
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| 
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| struct xfs_buf *xfs_buf_alloc(struct xfs_buftarg *, xfs_off_t, size_t,
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| 			      xfs_buf_flags_t);
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| extern void xfs_buf_set_empty(struct xfs_buf *bp, size_t len);
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| extern xfs_buf_t *xfs_buf_get_uncached(struct xfs_buftarg *, size_t, int);
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| extern int xfs_buf_associate_memory(xfs_buf_t *, void *, size_t);
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| extern void xfs_buf_hold(xfs_buf_t *);
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| extern void xfs_buf_readahead(xfs_buftarg_t *, xfs_off_t, size_t);
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| struct xfs_buf *xfs_buf_read_uncached(struct xfs_mount *mp,
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| 				struct xfs_buftarg *target,
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| 				xfs_daddr_t daddr, size_t length, int flags);
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| 
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| /* Releasing Buffers */
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| extern void xfs_buf_free(xfs_buf_t *);
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| extern void xfs_buf_rele(xfs_buf_t *);
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| 
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| /* Locking and Unlocking Buffers */
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| extern int xfs_buf_trylock(xfs_buf_t *);
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| extern void xfs_buf_lock(xfs_buf_t *);
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| extern void xfs_buf_unlock(xfs_buf_t *);
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| #define xfs_buf_islocked(bp) \
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| 	((bp)->b_sema.count <= 0)
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| 
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| /* Buffer Read and Write Routines */
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| extern int xfs_bwrite(struct xfs_buf *bp);
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| 
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| extern void xfsbdstrat(struct xfs_mount *, struct xfs_buf *);
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| extern int xfs_bdstrat_cb(struct xfs_buf *);
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| 
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| extern void xfs_buf_ioend(xfs_buf_t *,	int);
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| extern void xfs_buf_ioerror(xfs_buf_t *, int);
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| extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func);
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| extern int xfs_buf_iorequest(xfs_buf_t *);
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| extern int xfs_buf_iowait(xfs_buf_t *);
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| extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *,
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| 				xfs_buf_rw_t);
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| #define xfs_buf_zero(bp, off, len) \
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| 	    xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO)
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| 
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| static inline int xfs_buf_geterror(xfs_buf_t *bp)
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| {
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| 	return bp ? bp->b_error : ENOMEM;
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| }
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| 
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| /* Buffer Utility Routines */
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| extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t);
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| 
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| /* Delayed Write Buffer Routines */
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| extern void xfs_buf_delwri_queue(struct xfs_buf *);
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| extern void xfs_buf_delwri_dequeue(struct xfs_buf *);
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| extern void xfs_buf_delwri_promote(struct xfs_buf *);
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| 
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| /* Buffer Daemon Setup Routines */
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| extern int xfs_buf_init(void);
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| extern void xfs_buf_terminate(void);
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| 
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| #define XFS_BUF_ZEROFLAGS(bp) \
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| 	((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI| \
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| 			    XBF_SYNCIO|XBF_FUA|XBF_FLUSH))
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| 
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| void xfs_buf_stale(struct xfs_buf *bp);
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| #define XFS_BUF_UNSTALE(bp)	((bp)->b_flags &= ~XBF_STALE)
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| #define XFS_BUF_ISSTALE(bp)	((bp)->b_flags & XBF_STALE)
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| 
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| #define XFS_BUF_ISDELAYWRITE(bp)	((bp)->b_flags & XBF_DELWRI)
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| 
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| #define XFS_BUF_DONE(bp)	((bp)->b_flags |= XBF_DONE)
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| #define XFS_BUF_UNDONE(bp)	((bp)->b_flags &= ~XBF_DONE)
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| #define XFS_BUF_ISDONE(bp)	((bp)->b_flags & XBF_DONE)
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| 
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| #define XFS_BUF_ASYNC(bp)	((bp)->b_flags |= XBF_ASYNC)
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| #define XFS_BUF_UNASYNC(bp)	((bp)->b_flags &= ~XBF_ASYNC)
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| #define XFS_BUF_ISASYNC(bp)	((bp)->b_flags & XBF_ASYNC)
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| 
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| #define XFS_BUF_READ(bp)	((bp)->b_flags |= XBF_READ)
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| #define XFS_BUF_UNREAD(bp)	((bp)->b_flags &= ~XBF_READ)
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| #define XFS_BUF_ISREAD(bp)	((bp)->b_flags & XBF_READ)
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| 
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| #define XFS_BUF_WRITE(bp)	((bp)->b_flags |= XBF_WRITE)
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| #define XFS_BUF_UNWRITE(bp)	((bp)->b_flags &= ~XBF_WRITE)
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| #define XFS_BUF_ISWRITE(bp)	((bp)->b_flags & XBF_WRITE)
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| 
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| #define XFS_BUF_ADDR(bp)		((bp)->b_bn)
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| #define XFS_BUF_SET_ADDR(bp, bno)	((bp)->b_bn = (xfs_daddr_t)(bno))
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| #define XFS_BUF_OFFSET(bp)		((bp)->b_file_offset)
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| #define XFS_BUF_SET_OFFSET(bp, off)	((bp)->b_file_offset = (off))
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| #define XFS_BUF_COUNT(bp)		((bp)->b_count_desired)
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| #define XFS_BUF_SET_COUNT(bp, cnt)	((bp)->b_count_desired = (cnt))
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| #define XFS_BUF_SIZE(bp)		((bp)->b_buffer_length)
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| #define XFS_BUF_SET_SIZE(bp, cnt)	((bp)->b_buffer_length = (cnt))
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| 
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| static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref)
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| {
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| 	atomic_set(&bp->b_lru_ref, lru_ref);
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| }
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| 
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| static inline int xfs_buf_ispinned(struct xfs_buf *bp)
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| {
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| 	return atomic_read(&bp->b_pin_count);
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| }
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| 
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| static inline void xfs_buf_relse(xfs_buf_t *bp)
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| {
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| 	xfs_buf_unlock(bp);
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| 	xfs_buf_rele(bp);
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| }
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| 
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| /*
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|  *	Handling of buftargs.
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|  */
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| extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *,
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| 			struct block_device *, int, const char *);
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| extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *);
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| extern void xfs_wait_buftarg(xfs_buftarg_t *);
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| extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int);
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| extern int xfs_flush_buftarg(xfs_buftarg_t *, int);
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| 
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| #define xfs_getsize_buftarg(buftarg)	block_size((buftarg)->bt_bdev)
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| #define xfs_readonly_buftarg(buftarg)	bdev_read_only((buftarg)->bt_bdev)
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| 
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| #endif	/* __XFS_BUF_H__ */
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