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Diffstat (limited to 'fs/xfs/xfs_buf.h')
| -rw-r--r-- | fs/xfs/xfs_buf.h | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h new file mode 100644 index 000000000000..5bab046e859f --- /dev/null +++ b/fs/xfs/xfs_buf.h @@ -0,0 +1,297 @@ +/* + * Copyright (c) 2000-2005 Silicon Graphics, Inc. + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ +#ifndef __XFS_BUF_H__ +#define __XFS_BUF_H__ + +#include <linux/list.h> +#include <linux/types.h> +#include <linux/spinlock.h> +#include <asm/system.h> +#include <linux/mm.h> +#include <linux/fs.h> +#include <linux/buffer_head.h> +#include <linux/uio.h> + +/* + * Base types + */ + +#define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL)) + +#define xfs_buf_ctob(pp) ((pp) * PAGE_CACHE_SIZE) +#define xfs_buf_btoc(dd) (((dd) + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT) +#define xfs_buf_btoct(dd) ((dd) >> PAGE_CACHE_SHIFT) +#define xfs_buf_poff(aa) ((aa) & ~PAGE_CACHE_MASK) + +typedef enum { + XBRW_READ = 1, /* transfer into target memory */ + XBRW_WRITE = 2, /* transfer from target memory */ + XBRW_ZERO = 3, /* Zero target memory */ +} xfs_buf_rw_t; + +#define XBF_READ (1 << 0) /* buffer intended for reading from device */ +#define XBF_WRITE (1 << 1) /* buffer intended for writing to device */ +#define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */ +#define XBF_MAPPED (1 << 3) /* buffer mapped (b_addr valid) */ +#define XBF_ASYNC (1 << 4) /* initiator will not wait for completion */ +#define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */ +#define XBF_DELWRI (1 << 6) /* buffer has dirty pages */ +#define XBF_STALE (1 << 7) /* buffer has been staled, do not find it */ + +/* I/O hints for the BIO layer */ +#define XBF_SYNCIO (1 << 10)/* treat this buffer as synchronous I/O */ +#define XBF_FUA (1 << 11)/* force cache write through mode */ +#define XBF_FLUSH (1 << 12)/* flush the disk cache before a write */ + +/* flags used only as arguments to access routines */ +#define XBF_LOCK (1 << 15)/* lock requested */ +#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */ +#define XBF_DONT_BLOCK (1 << 17)/* do not block in current thread */ + +/* flags used only internally */ +#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */ +#define _XBF_KMEM (1 << 21)/* backed by heap memory */ +#define _XBF_DELWRI_Q (1 << 22)/* buffer on delwri queue */ + +typedef unsigned int xfs_buf_flags_t; + +#define XFS_BUF_FLAGS \ + { XBF_READ, "READ" }, \ + { XBF_WRITE, "WRITE" }, \ + { XBF_READ_AHEAD, "READ_AHEAD" }, \ + { XBF_MAPPED, "MAPPED" }, \ + { XBF_ASYNC, "ASYNC" }, \ + { XBF_DONE, "DONE" }, \ + { XBF_DELWRI, "DELWRI" }, \ + { XBF_STALE, "STALE" }, \ + { XBF_SYNCIO, "SYNCIO" }, \ + { XBF_FUA, "FUA" }, \ + { XBF_FLUSH, "FLUSH" }, \ + { XBF_LOCK, "LOCK" }, /* should never be set */\ + { XBF_TRYLOCK, "TRYLOCK" }, /* ditto */\ + { XBF_DONT_BLOCK, "DONT_BLOCK" }, /* ditto */\ + { _XBF_PAGES, "PAGES" }, \ + { _XBF_KMEM, "KMEM" }, \ + { _XBF_DELWRI_Q, "DELWRI_Q" } + +typedef enum { + XBT_FORCE_SLEEP = 0, + XBT_FORCE_FLUSH = 1, +} xfs_buftarg_flags_t; + +typedef struct xfs_buftarg { + dev_t bt_dev; + struct block_device *bt_bdev; + struct backing_dev_info *bt_bdi; + struct xfs_mount *bt_mount; + unsigned int bt_bsize; + unsigned int bt_sshift; + size_t bt_smask; + + /* per device delwri queue */ + struct task_struct *bt_task; + struct list_head bt_delwri_queue; + spinlock_t bt_delwri_lock; + unsigned long bt_flags; + + /* LRU control structures */ + struct shrinker bt_shrinker; + struct list_head bt_lru; + spinlock_t bt_lru_lock; + unsigned int bt_lru_nr; +} xfs_buftarg_t; + +struct xfs_buf; +typedef void (*xfs_buf_iodone_t)(struct xfs_buf *); + +#define XB_PAGES 2 + +typedef struct xfs_buf { + /* + * first cacheline holds all the fields needed for an uncontended cache + * hit to be fully processed. The semaphore straddles the cacheline + * boundary, but the counter and lock sits on the first cacheline, + * which is the only bit that is touched if we hit the semaphore + * fast-path on locking. + */ + struct rb_node b_rbnode; /* rbtree node */ + xfs_off_t b_file_offset; /* offset in file */ + size_t b_buffer_length;/* size of buffer in bytes */ + atomic_t b_hold; /* reference count */ + atomic_t b_lru_ref; /* lru reclaim ref count */ + xfs_buf_flags_t b_flags; /* status flags */ + struct semaphore b_sema; /* semaphore for lockables */ + + struct list_head b_lru; /* lru list */ + wait_queue_head_t b_waiters; /* unpin waiters */ + struct list_head b_list; + struct xfs_perag *b_pag; /* contains rbtree root */ + xfs_buftarg_t *b_target; /* buffer target (device) */ + xfs_daddr_t b_bn; /* block number for I/O */ + size_t b_count_desired;/* desired transfer size */ + void *b_addr; /* virtual address of buffer */ + struct work_struct b_iodone_work; + xfs_buf_iodone_t b_iodone; /* I/O completion function */ + struct completion b_iowait; /* queue for I/O waiters */ + void *b_fspriv; + struct xfs_trans *b_transp; + struct page **b_pages; /* array of page pointers */ + struct page *b_page_array[XB_PAGES]; /* inline pages */ + unsigned long b_queuetime; /* time buffer was queued */ + atomic_t b_pin_count; /* pin count */ + atomic_t b_io_remaining; /* #outstanding I/O requests */ + unsigned int b_page_count; /* size of page array */ + unsigned int b_offset; /* page offset in first page */ + unsigned short b_error; /* error code on I/O */ +#ifdef XFS_BUF_LOCK_TRACKING + int b_last_holder; +#endif +} xfs_buf_t; + + +/* Finding and Reading Buffers */ +extern xfs_buf_t *_xfs_buf_find(xfs_buftarg_t *, xfs_off_t, size_t, + xfs_buf_flags_t, xfs_buf_t *); +#define xfs_incore(buftarg,blkno,len,lockit) \ + _xfs_buf_find(buftarg, blkno ,len, lockit, NULL) + +extern xfs_buf_t *xfs_buf_get(xfs_buftarg_t *, xfs_off_t, size_t, + xfs_buf_flags_t); +extern xfs_buf_t *xfs_buf_read(xfs_buftarg_t *, xfs_off_t, size_t, + xfs_buf_flags_t); + +struct xfs_buf *xfs_buf_alloc(struct xfs_buftarg *, xfs_off_t, size_t, + xfs_buf_flags_t); +extern void xfs_buf_set_empty(struct xfs_buf *bp, size_t len); +extern xfs_buf_t *xfs_buf_get_uncached(struct xfs_buftarg *, size_t, int); +extern int xfs_buf_associate_memory(xfs_buf_t *, void *, size_t); +extern void xfs_buf_hold(xfs_buf_t *); +extern void xfs_buf_readahead(xfs_buftarg_t *, xfs_off_t, size_t); +struct xfs_buf *xfs_buf_read_uncached(struct xfs_mount *mp, + struct xfs_buftarg *target, + xfs_daddr_t daddr, size_t length, int flags); + +/* Releasing Buffers */ +extern void xfs_buf_free(xfs_buf_t *); +extern void xfs_buf_rele(xfs_buf_t *); + +/* Locking and Unlocking Buffers */ +extern int xfs_buf_trylock(xfs_buf_t *); +extern void xfs_buf_lock(xfs_buf_t *); +extern void xfs_buf_unlock(xfs_buf_t *); +#define xfs_buf_islocked(bp) \ + ((bp)->b_sema.count <= 0) + +/* Buffer Read and Write Routines */ +extern int xfs_bwrite(struct xfs_buf *bp); + +extern void xfsbdstrat(struct xfs_mount *, struct xfs_buf *); +extern int xfs_bdstrat_cb(struct xfs_buf *); + +extern void xfs_buf_ioend(xfs_buf_t *, int); +extern void xfs_buf_ioerror(xfs_buf_t *, int); +extern void xfs_buf_ioerror_alert(struct xfs_buf *, const char *func); +extern int xfs_buf_iorequest(xfs_buf_t *); +extern int xfs_buf_iowait(xfs_buf_t *); +extern void xfs_buf_iomove(xfs_buf_t *, size_t, size_t, void *, + xfs_buf_rw_t); +#define xfs_buf_zero(bp, off, len) \ + xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO) + +static inline int xfs_buf_geterror(xfs_buf_t *bp) +{ + return bp ? bp->b_error : ENOMEM; +} + +/* Buffer Utility Routines */ +extern xfs_caddr_t xfs_buf_offset(xfs_buf_t *, size_t); + +/* Delayed Write Buffer Routines */ +extern void xfs_buf_delwri_queue(struct xfs_buf *); +extern void xfs_buf_delwri_dequeue(struct xfs_buf *); +extern void xfs_buf_delwri_promote(struct xfs_buf *); + +/* Buffer Daemon Setup Routines */ +extern int xfs_buf_init(void); +extern void xfs_buf_terminate(void); + +#define XFS_BUF_ZEROFLAGS(bp) \ + ((bp)->b_flags &= ~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI| \ + XBF_SYNCIO|XBF_FUA|XBF_FLUSH)) + +void xfs_buf_stale(struct xfs_buf *bp); +#define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XBF_STALE) +#define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XBF_STALE) + +#define XFS_BUF_ISDELAYWRITE(bp) ((bp)->b_flags & XBF_DELWRI) + +#define XFS_BUF_DONE(bp) ((bp)->b_flags |= XBF_DONE) +#define XFS_BUF_UNDONE(bp) ((bp)->b_flags &= ~XBF_DONE) +#define XFS_BUF_ISDONE(bp) ((bp)->b_flags & XBF_DONE) + +#define XFS_BUF_ASYNC(bp) ((bp)->b_flags |= XBF_ASYNC) +#define XFS_BUF_UNASYNC(bp) ((bp)->b_flags &= ~XBF_ASYNC) +#define XFS_BUF_ISASYNC(bp) ((bp)->b_flags & XBF_ASYNC) + +#define XFS_BUF_READ(bp) ((bp)->b_flags |= XBF_READ) +#define XFS_BUF_UNREAD(bp) ((bp)->b_flags &= ~XBF_READ) +#define XFS_BUF_ISREAD(bp) ((bp)->b_flags & XBF_READ) + +#define XFS_BUF_WRITE(bp) ((bp)->b_flags |= XBF_WRITE) +#define XFS_BUF_UNWRITE(bp) ((bp)->b_flags &= ~XBF_WRITE) +#define XFS_BUF_ISWRITE(bp) ((bp)->b_flags & XBF_WRITE) + +#define XFS_BUF_ADDR(bp) ((bp)->b_bn) +#define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_bn = (xfs_daddr_t)(bno)) +#define XFS_BUF_OFFSET(bp) ((bp)->b_file_offset) +#define XFS_BUF_SET_OFFSET(bp, off) ((bp)->b_file_offset = (off)) +#define XFS_BUF_COUNT(bp) ((bp)->b_count_desired) +#define XFS_BUF_SET_COUNT(bp, cnt) ((bp)->b_count_desired = (cnt)) +#define XFS_BUF_SIZE(bp) ((bp)->b_buffer_length) +#define XFS_BUF_SET_SIZE(bp, cnt) ((bp)->b_buffer_length = (cnt)) + +static inline void xfs_buf_set_ref(struct xfs_buf *bp, int lru_ref) +{ + atomic_set(&bp->b_lru_ref, lru_ref); +} + +static inline int xfs_buf_ispinned(struct xfs_buf *bp) +{ + return atomic_read(&bp->b_pin_count); +} + +static inline void xfs_buf_relse(xfs_buf_t *bp) +{ + xfs_buf_unlock(bp); + xfs_buf_rele(bp); +} + +/* + * Handling of buftargs. + */ +extern xfs_buftarg_t *xfs_alloc_buftarg(struct xfs_mount *, + struct block_device *, int, const char *); +extern void xfs_free_buftarg(struct xfs_mount *, struct xfs_buftarg *); +extern void xfs_wait_buftarg(xfs_buftarg_t *); +extern int xfs_setsize_buftarg(xfs_buftarg_t *, unsigned int, unsigned int); +extern int xfs_flush_buftarg(xfs_buftarg_t *, int); + +#define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) +#define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) + +#endif /* __XFS_BUF_H__ */ |