/* * 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; typedef enum { XBF_READ = (1 << 0), /* buffer intended for reading from device */ XBF_WRITE = (1 << 1), /* buffer intended for writing to device */ XBF_MAPPED = (1 << 2), /* buffer mapped (b_addr valid) */ XBF_ASYNC = (1 << 4), /* initiator will not wait for completion */ XBF_DONE = (1 << 5), /* all pages in the buffer uptodate */ XBF_DELWRI = (1 << 6), /* buffer has dirty pages */ XBF_STALE = (1 << 7), /* buffer has been staled, do not find it */ XBF_FS_MANAGED = (1 << 8), /* filesystem controls freeing memory */ XBF_ORDERED = (1 << 11), /* use ordered writes */ XBF_READ_AHEAD = (1 << 12), /* asynchronous read-ahead */ /* flags used only as arguments to access routines */ XBF_LOCK = (1 << 14), /* lock requested */ XBF_TRYLOCK = (1 << 15), /* lock requested, but do not wait */ XBF_DONT_BLOCK = (1 << 16), /* do not block in current thread */ /* flags used only internally */ _XBF_PAGE_CACHE = (1 << 17),/* backed by pagecache */ _XBF_PAGES = (1 << 18), /* backed by refcounted pages */ _XBF_RUN_QUEUES = (1 << 19),/* run block device task queue */ _XBF_DELWRI_Q = (1 << 21), /* buffer on delwri queue */ /* * Special flag for supporting metadata blocks smaller than a FSB. * * In this case we can have multiple xfs_buf_t on a single page and * need to lock out concurrent xfs_buf_t readers as they only * serialise access to the buffer. * * If the FSB size >= PAGE_CACHE_SIZE case, we have no serialisation * between reads of the page. Hence we can have one thread read the * page and modify it, but then race with another thread that thinks * the page is not up-to-date and hence reads it again. * * The result is that the first modifcation to the page is lost. * This sort of AGF/AGI reading race can happen when unlinking inodes * that require truncation and results in the AGI unlinked list * modifications being lost. */ _XBF_PAGE_LOCKED = (1 << 22), /* * If we try a barrier write, but it fails we have to communicate * this to the upper layers. Unfortunately b_error gets overwritten * when the buffer is re-issued so we have to add another flag to * keep this information. */ _XFS_BARRIER_FAILED = (1 << 23), } xfs_buf_flags_t; typedef enum { XBT_FORCE_SLEEP = 0, XBT_FORCE_FLUSH = 1, } xfs_buftarg_flags_t; typedef struct xfs_bufhash { struct list_head bh_list; spinlock_t bh_lock; } xfs_bufhash_t; typedef struct xfs_buftarg { dev_t bt_dev; struct block_device *bt_bdev; struct address_space *bt_mapping; unsigned int bt_bsize; unsigned int bt_sshift; size_t bt_smask; /* per device buffer hash table */ uint bt_hashmask; uint bt_hashshift; xfs_bufhash_t *bt_hash; /* per device delwri queue */ struct task_struct *bt_task; struct list_head bt_list; struct list_head bt_delwrite_queue; spinlock_t bt_delwrite_lock; unsigned long bt_flags; } xfs_buftarg_t; /* * xfs_buf_t: Buffer structure for pagecache-based buffers * * This buffer structure is used by the pagecache buffer management routines * to refer to an assembly of pages forming a logical buffer. * * The buffer structure is used on a temporary basis only, and discarded when * released. The real data storage is recorded in the pagecache. Buffers are * hashed to the block device on which the file system resides. */ struct xfs_buf; typedef void (*xfs_buf_iodone_t)(struct xfs_buf *); typedef void (*xfs_buf_relse_t)(struct xfs_buf *); typedef int (*xfs_buf_bdstrat_t)(struct xfs_buf *); #define XB_PAGES 2 typedef struct xfs_buf { struct semaphore b_sema; /* semaphore for lockables */ unsigned long b_queuetime; /* time buffer was queued */ atomic_t b_pin_count; /* pin count */ wait_queue_head_t b_waiters; /* unpin waiters */ struct list_head b_list; xfs_buf_flags_t b_flags; /* status flags */ struct list_head b_hash_list; /* hash table list */ xfs_bufhash_t *b_hash; /* hash table list start */ xfs_buftarg_t *b_target; /* buffer target (device) */ atomic_t b_hold; /* reference count */ xfs_daddr_t b_bn; /* block number for I/O */ xfs_off_t b_file_offset; /* offset in file */ size_t b_buffer_length;/* size of buffer in bytes */ size_t b_count_desired;/* desired transfer size */ void *b_addr; /* virtual address of buffer */ struct work_struct b_iodone_work; atomic_t b_io_remaining; /* #outstanding I/O requests */ xfs_buf_iodone_t b_iodone; /* I/O completion function */ xfs_buf_relse_t b_relse; /* releasing function */ xfs_buf_bdstrat_t b_strat; /* pre-write function */ struct completion b_iowait; /* queue for I/O waiters */ void *b_fspriv; void *b_fspriv2; struct xfs_mount *b_mount; unsigned short b_error; /* error code on I/O */ unsigned int b_page_count; /* size of page array */ unsigned int b_offset; /* page offset in first page */ struct page **b_pages; /* array of page pointers */ struct page *b_page_array[XB_PAGES]; /* inline pages */ #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_flags(xfs_buftarg_t *, xfs_off_t, size_t, xfs_buf_flags_t); #define xfs_buf_get(target, blkno, len, flags) \ xfs_buf_get_flags((target), (blkno), (len), XBF_LOCK | XBF_MAPPED) extern xfs_buf_t *xfs_buf_read_flags(xfs_buftarg_t *, xfs_off_t, size_t, xfs_buf_flags_t); #define xfs_buf_read(target, blkno, len, flags) \ xfs_buf_read_flags((target), (blkno), (len), XBF_LOCK | XBF_MAPPED) extern xfs_buf_t *xfs_buf_get_empty(size_t, xfs_buftarg_t *); extern xfs_buf_t *xfs_buf_get_noaddr(size_t, xfs_buftarg_t *); 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, xfs_buf_flags_t); /* 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_cond_lock(xfs_buf_t *); extern int xfs_buf_lock_value(xfs_buf_t *); extern void xfs_buf_lock(xfs_buf_t *); extern void xfs_buf_unlock(xfs_buf_t *); /* Buffer Read and Write Routines */ extern int xfs_bawrite(void *mp, xfs_buf_t *bp); extern void xfs_bdwrite(void *mp, xfs_buf_t *bp); 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, xfs_caddr_t, xfs_buf_rw_t); static inline int xfs_buf_iostrategy(xfs_buf_t *bp) { return bp->b_strat ? bp->b_strat(bp) : xfs_buf_iorequest(bp); } 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); /* Pinning Buffer Storage in Memory */ extern void xfs_buf_pin(xfs_buf_t *); extern void xfs_buf_unpin(xfs_buf_t *); extern int xfs_buf_ispin(xfs_buf_t *); /* Delayed Write Buffer Routines */ extern void xfs_buf_delwri_dequeue(xfs_buf_t *); /* Buffer Daemon Setup Routines */ extern int xfs_buf_init(void); extern void xfs_buf_terminate(void); #ifdef XFS_BUF_TRACE extern ktrace_t *xfs_buf_trace_buf; extern void xfs_buf_trace(xfs_buf_t *, char *, void *, void *); #else #define xfs_buf_trace(bp,id,ptr,ra) do { } while (0) #endif #define xfs_buf_target_name(target) \ ({ char __b[BDEVNAME_SIZE]; bdevname((target)->bt_bdev, __b); __b; }) #define XFS_B_ASYNC XBF_ASYNC #define XFS_B_DELWRI XBF_DELWRI #define XFS_B_READ XBF_READ #define XFS_B_WRITE XBF_WRITE #define XFS_B_STALE XBF_STALE #define XFS_BUF_TRYLOCK XBF_TRYLOCK #define XFS_INCORE_TRYLOCK XBF_TRYLOCK #define XFS_BUF_LOCK XBF_LOCK #define XFS_BUF_MAPPED XBF_MAPPED #define BUF_BUSY XBF_DONT_BLOCK #define XFS_BUF_BFLAGS(bp) ((bp)->b_flags) #define XFS_BUF_ZEROFLAGS(bp) ((bp)->b_flags &= \ ~(XBF_READ|XBF_WRITE|XBF_ASYNC|XBF_DELWRI|XBF_ORDERED)) #define XFS_BUF_STALE(bp) ((bp)->b_flags |= XFS_B_STALE) #define XFS_BUF_UNSTALE(bp) ((bp)->b_flags &= ~XFS_B_STALE) #define XFS_BUF_ISSTALE(bp) ((bp)->b_flags & XFS_B_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_MANAGE XBF_FS_MANAGED #define XFS_BUF_UNMANAGE(bp) ((bp)->b_flags &= ~XBF_FS_MANAGED) #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_ERROR(bp,no) xfs_buf_ioerror(bp,no) #define XFS_BUF_GETERROR(bp) xfs_buf_geterror(bp) #define XFS_BUF_ISERROR(bp) (xfs_buf_geterror(bp) ? 1 : 0) #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_BUSY(bp) do { } while (0) #define XFS_BUF_UNBUSY(bp) do { } while (0) #define XFS_BUF_ISBUSY(bp) (1) #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_ORDERED(bp) ((bp)->b_flags |= XBF_ORDERED) #define XFS_BUF_UNORDERED(bp) ((bp)->b_flags &= ~XBF_ORDERED) #define XFS_BUF_ISORDERED(bp) ((bp)->b_flags & XBF_ORDERED) #define XFS_BUF_HOLD(bp) xfs_buf_hold(bp) #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_IODONE_FUNC(bp) ((bp)->b_iodone) #define XFS_BUF_SET_IODONE_FUNC(bp, func) ((bp)->b_iodone = (func)) #define XFS_BUF_CLR_IODONE_FUNC(bp) ((bp)->b_iodone = NULL) #define XFS_BUF_SET_BDSTRAT_FUNC(bp, func) ((bp)->b_strat = (func)) #define XFS_BUF_CLR_BDSTRAT_FUNC(bp) ((bp)->b_strat = NULL) #define XFS_BUF_FSPRIVATE(bp, type) ((type)(bp)->b_fspriv) #define XFS_BUF_SET_FSPRIVATE(bp, val) ((bp)->b_fspriv = (void*)(val)) #define XFS_BUF_FSPRIVATE2(bp, type) ((type)(bp)->b_fspriv2) #define XFS_BUF_SET_FSPRIVATE2(bp, val) ((bp)->b_fspriv2 = (void*)(val)) #define XFS_BUF_SET_START(bp) do { } while (0) #define XFS_BUF_SET_BRELSE_FUNC(bp, func) ((bp)->b_relse = (func)) #define XFS_BUF_PTR(bp) (xfs_caddr_t)((bp)->b_addr) #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)) #define XFS_BUF_SET_VTYPE_REF(bp, type, ref) do { } while (0) #define XFS_BUF_SET_VTYPE(bp, type) do { } while (0) #define XFS_BUF_SET_REF(bp, ref) do { } while (0) #define XFS_BUF_ISPINNED(bp) xfs_buf_ispin(bp) #define XFS_BUF_VALUSEMA(bp) xfs_buf_lock_value(bp) #define XFS_BUF_CPSEMA(bp) (xfs_buf_cond_lock(bp) == 0) #define XFS_BUF_VSEMA(bp) xfs_buf_unlock(bp) #define XFS_BUF_PSEMA(bp,x) xfs_buf_lock(bp) #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) { if (!bp->b_relse) xfs_buf_unlock(bp); xfs_buf_rele(bp); } #define xfs_bpin(bp) xfs_buf_pin(bp) #define xfs_bunpin(bp) xfs_buf_unpin(bp) #define xfs_buftrace(id, bp) \ xfs_buf_trace(bp, id, NULL, (void *)__builtin_return_address(0)) #define xfs_biodone(bp) xfs_buf_ioend(bp, 0) #define xfs_biomove(bp, off, len, data, rw) \ xfs_buf_iomove((bp), (off), (len), (data), \ ((rw) == XFS_B_WRITE) ? XBRW_WRITE : XBRW_READ) #define xfs_biozero(bp, off, len) \ xfs_buf_iomove((bp), (off), (len), NULL, XBRW_ZERO) static inline int XFS_bwrite(xfs_buf_t *bp) { int iowait = (bp->b_flags & XBF_ASYNC) == 0; int error = 0; if (!iowait) bp->b_flags |= _XBF_RUN_QUEUES; xfs_buf_delwri_dequeue(bp); xfs_buf_iostrategy(bp); if (iowait) { error = xfs_buf_iowait(bp); xfs_buf_relse(bp); } return error; } #define XFS_bdstrat(bp) xfs_buf_iorequest(bp) #define xfs_iowait(bp) xfs_buf_iowait(bp) #define xfs_baread(target, rablkno, ralen) \ xfs_buf_readahead((target), (rablkno), (ralen), XBF_DONT_BLOCK) /* * Handling of buftargs. */ extern xfs_buftarg_t *xfs_alloc_buftarg(struct block_device *, int); 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__ */