| /* |
| * 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 <linux/mm.h> |
| #include <linux/fs.h> |
| #include <linux/buffer_head.h> |
| #include <linux/uio.h> |
| #include <linux/list_lru.h> |
| |
| /* |
| * Base types |
| */ |
| |
| #define XFS_BUF_DADDR_NULL ((xfs_daddr_t) (-1LL)) |
| |
| 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_ASYNC (1 << 4) /* initiator will not wait for completion */ |
| #define XBF_DONE (1 << 5) /* all pages in the buffer uptodate */ |
| #define XBF_STALE (1 << 6) /* 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_TRYLOCK (1 << 16)/* lock requested, but do not wait */ |
| #define XBF_UNMAPPED (1 << 17)/* do not map the buffer */ |
| |
| /* 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 a delwri queue */ |
| #define _XBF_COMPOUND (1 << 23)/* compound buffer */ |
| #define _XBF_LRU_DISPOSE (1 << 24)/* buffer being discarded */ |
| |
| typedef unsigned int xfs_buf_flags_t; |
| |
| #define XFS_BUF_FLAGS \ |
| { XBF_READ, "READ" }, \ |
| { XBF_WRITE, "WRITE" }, \ |
| { XBF_READ_AHEAD, "READ_AHEAD" }, \ |
| { XBF_ASYNC, "ASYNC" }, \ |
| { XBF_DONE, "DONE" }, \ |
| { XBF_STALE, "STALE" }, \ |
| { XBF_SYNCIO, "SYNCIO" }, \ |
| { XBF_FUA, "FUA" }, \ |
| { XBF_FLUSH, "FLUSH" }, \ |
| { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\ |
| { XBF_UNMAPPED, "UNMAPPED" }, /* ditto */\ |
| { _XBF_PAGES, "PAGES" }, \ |
| { _XBF_KMEM, "KMEM" }, \ |
| { _XBF_DELWRI_Q, "DELWRI_Q" }, \ |
| { _XBF_COMPOUND, "COMPOUND" }, \ |
| { _XBF_LRU_DISPOSE, "LRU_DISPOSE" } |
| |
| 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; |
| |
| /* LRU control structures */ |
| struct shrinker bt_shrinker; |
| struct list_lru bt_lru; |
| } xfs_buftarg_t; |
| |
| struct xfs_buf; |
| typedef void (*xfs_buf_iodone_t)(struct xfs_buf *); |
| |
| |
| #define XB_PAGES 2 |
| |
| struct xfs_buf_map { |
| xfs_daddr_t bm_bn; /* block number for I/O */ |
| int bm_len; /* size of I/O */ |
| }; |
| |
| #define DEFINE_SINGLE_BUF_MAP(map, blkno, numblk) \ |
| struct xfs_buf_map (map) = { .bm_bn = (blkno), .bm_len = (numblk) }; |
| |
| struct xfs_buf_ops { |
| void (*verify_read)(struct xfs_buf *); |
| void (*verify_write)(struct xfs_buf *); |
| }; |
| |
| 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_daddr_t b_bn; /* block number of buffer */ |
| int b_length; /* size of buffer in BBs */ |
| 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 */ |
| |
| /* |
| * concurrent access to b_lru and b_lru_flags are protected by |
| * bt_lru_lock and not by b_sema |
| */ |
| struct list_head b_lru; /* lru list */ |
| xfs_buf_flags_t b_lru_flags; /* internal lru status flags */ |
| 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) */ |
| 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 */ |
| struct xfs_buf_map *b_maps; /* compound buffer map */ |
| struct xfs_buf_map __b_map; /* inline compound buffer map */ |
| int b_map_count; |
| int b_io_length; /* IO size in BBs */ |
| 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 */ |
| const struct xfs_buf_ops *b_ops; |
| |
| #ifdef XFS_BUF_LOCK_TRACKING |
| int b_last_holder; |
| #endif |
| } xfs_buf_t; |
| |
| /* Finding and Reading Buffers */ |
| struct xfs_buf *_xfs_buf_find(struct xfs_buftarg *target, |
| struct xfs_buf_map *map, int nmaps, |
| xfs_buf_flags_t flags, struct xfs_buf *new_bp); |
| |
| static inline struct xfs_buf * |
| xfs_incore( |
| struct xfs_buftarg *target, |
| xfs_daddr_t blkno, |
| size_t numblks, |
| xfs_buf_flags_t flags) |
| { |
| DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
| return _xfs_buf_find(target, &map, 1, flags, NULL); |
| } |
| |
| struct xfs_buf *_xfs_buf_alloc(struct xfs_buftarg *target, |
| struct xfs_buf_map *map, int nmaps, |
| xfs_buf_flags_t flags); |
| |
| static inline struct xfs_buf * |
| xfs_buf_alloc( |
| struct xfs_buftarg *target, |
| xfs_daddr_t blkno, |
| size_t numblks, |
| xfs_buf_flags_t flags) |
| { |
| DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
| return _xfs_buf_alloc(target, &map, 1, flags); |
| } |
| |
| struct xfs_buf *xfs_buf_get_map(struct xfs_buftarg *target, |
| struct xfs_buf_map *map, int nmaps, |
| xfs_buf_flags_t flags); |
| struct xfs_buf *xfs_buf_read_map(struct xfs_buftarg *target, |
| struct xfs_buf_map *map, int nmaps, |
| xfs_buf_flags_t flags, |
| const struct xfs_buf_ops *ops); |
| void xfs_buf_readahead_map(struct xfs_buftarg *target, |
| struct xfs_buf_map *map, int nmaps, |
| const struct xfs_buf_ops *ops); |
| |
| static inline struct xfs_buf * |
| xfs_buf_get( |
| struct xfs_buftarg *target, |
| xfs_daddr_t blkno, |
| size_t numblks, |
| xfs_buf_flags_t flags) |
| { |
| DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
| return xfs_buf_get_map(target, &map, 1, flags); |
| } |
| |
| static inline struct xfs_buf * |
| xfs_buf_read( |
| struct xfs_buftarg *target, |
| xfs_daddr_t blkno, |
| size_t numblks, |
| xfs_buf_flags_t flags, |
| const struct xfs_buf_ops *ops) |
| { |
| DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
| return xfs_buf_read_map(target, &map, 1, flags, ops); |
| } |
| |
| static inline void |
| xfs_buf_readahead( |
| struct xfs_buftarg *target, |
| xfs_daddr_t blkno, |
| size_t numblks, |
| const struct xfs_buf_ops *ops) |
| { |
| DEFINE_SINGLE_BUF_MAP(map, blkno, numblks); |
| return xfs_buf_readahead_map(target, &map, 1, ops); |
| } |
| |
| struct xfs_buf *xfs_buf_get_empty(struct xfs_buftarg *target, size_t numblks); |
| void xfs_buf_set_empty(struct xfs_buf *bp, size_t numblks); |
| int xfs_buf_associate_memory(struct xfs_buf *bp, void *mem, size_t length); |
| |
| struct xfs_buf *xfs_buf_get_uncached(struct xfs_buftarg *target, size_t numblks, |
| int flags); |
| struct xfs_buf *xfs_buf_read_uncached(struct xfs_buftarg *target, |
| xfs_daddr_t daddr, size_t numblks, int flags, |
| const struct xfs_buf_ops *ops); |
| void xfs_buf_hold(struct xfs_buf *bp); |
| |
| /* 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 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 void 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 bool xfs_buf_delwri_queue(struct xfs_buf *, struct list_head *); |
| extern int xfs_buf_delwri_submit(struct list_head *); |
| extern int xfs_buf_delwri_submit_nowait(struct list_head *); |
| |
| /* 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_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_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) |
| |
| /* |
| * These macros use the IO block map rather than b_bn. b_bn is now really |
| * just for the buffer cache index for cached buffers. As IO does not use b_bn |
| * anymore, uncached buffers do not use b_bn at all and hence must modify the IO |
| * map directly. Uncached buffers are not allowed to be discontiguous, so this |
| * is safe to do. |
| * |
| * In future, uncached buffers will pass the block number directly to the io |
| * request function and hence these macros will go away at that point. |
| */ |
| #define XFS_BUF_ADDR(bp) ((bp)->b_maps[0].bm_bn) |
| #define XFS_BUF_SET_ADDR(bp, bno) ((bp)->b_maps[0].bm_bn = (xfs_daddr_t)(bno)) |
| |
| 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); |
| |
| #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__ */ |