/* * 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 #include #include #include #include #include #include #include /* * 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_delwrite_queue; spinlock_t bt_delwrite_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); extern xfs_buf_t *xfs_buf_get_empty(size_t, xfs_buftarg_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_mount *mp, struct xfs_buf *bp); extern void xfs_bdwrite(void *mp, xfs_buf_t *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 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_dequeue(xfs_buf_t *); extern void xfs_buf_delwri_promote(xfs_buf_t *); /* Buffer Daemon Setup Routines */ extern int xfs_buf_init(void); extern void xfs_buf_terminate(void); #define xfs_buf_target_name(target) \ ({ char __b[BDEVNAME_SIZE]; bdevname((target)->bt_bdev, __b); __b; }) #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_STALE(bp) xfs_buf_stale(bp); #define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XBF_STALE) #define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XBF_STALE) #define XFS_BUF_SUPER_STALE(bp) do { \ XFS_BUF_STALE(bp); \ xfs_buf_delwri_dequeue(bp); \ XFS_BUF_DONE(bp); \ } while (0) #define XFS_BUF_DELAYWRITE(bp) ((bp)->b_flags |= XBF_DELWRI) #define XFS_BUF_UNDELAYWRITE(bp) xfs_buf_delwri_dequeue(bp) #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_SET_PTR(bp, val, cnt) xfs_buf_associate_memory(bp, val, cnt) #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); } #define XFS_BUF_SET_VTYPE_REF(bp, type, ref) xfs_buf_set_ref(bp, ref) #define XFS_BUF_SET_VTYPE(bp, type) do { } while (0) #define XFS_BUF_ISPINNED(bp) atomic_read(&((bp)->b_pin_count)) #define XFS_BUF_FINISH_IOWAIT(bp) complete(&bp->b_iowait); #define XFS_BUF_SET_TARGET(bp, target) ((bp)->b_target = (target)) #define XFS_BUF_TARGET(bp) ((bp)->b_target) #define XFS_BUFTARG_NAME(target) xfs_buf_target_name(target) 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); #ifdef CONFIG_KDB_MODULES extern struct list_head *xfs_get_buftarg_list(void); #endif #define xfs_getsize_buftarg(buftarg) block_size((buftarg)->bt_bdev) #define xfs_readonly_buftarg(buftarg) bdev_read_only((buftarg)->bt_bdev) #define xfs_binval(buftarg) xfs_flush_buftarg(buftarg, 1) #define XFS_bflush(buftarg) xfs_flush_buftarg(buftarg, 1) #endif /* __XFS_BUF_H__ */