From 939d723b721eef71060201738653a73443ff4510 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 20 Jul 2010 17:51:16 +1000 Subject: xfs: kill the b_strat callback in xfs_buf The b_strat callback is used by xfs_buf_iostrategy to perform additional checks before submitting a buffer. It is used in xfs_bwrite and when writing out delayed buffers. In xfs_bwrite it we can de-virtualize the call easily as b_strat is set a few lines above the call to xfs_buf_iostrategy. For the delayed buffers the rationale is a bit more complicated: - there are three callers of xfs_buf_delwri_queue, which places buffers on the delwri list: (1) xfs_bdwrite - this sets up b_strat, so it's fine (2) xfs_buf_iorequest. None of the callers can have XBF_DELWRI set: - xlog_bdstrat is only used for log buffers, which are never delwri - _xfs_buf_read explicitly clears the delwri flag - xfs_buf_iodone_work retries log buffers only - xfsbdstrat - only used for reads, superblock writes without the delwri flag, log I/O and file zeroing with explicitly allocated buffers. - xfs_buf_iostrategy - only calls xfs_buf_iorequest if b_strat is not set (3) xfs_buf_unlock - only puts the buffer on the delwri list if the DELWRI flag is already set. The DELWRI flag is only ever set in xfs_bwrite, xfs_buf_iodone_callbacks, or xfs_trans_log_buf. For xfs_buf_iodone_callbacks and xfs_trans_log_buf we require an initialized buf item, which means b_strat was set to xfs_bdstrat_cb in xfs_buf_item_init. Conclusion: we can just get rid of the callback and replace it with explicit calls to xfs_bdstrat_cb. Signed-off-by: Christoph Hellwig Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/linux-2.6/xfs_buf.c | 10 +++------- fs/xfs/linux-2.6/xfs_buf.h | 8 -------- 2 files changed, 3 insertions(+), 15 deletions(-) (limited to 'fs/xfs/linux-2.6') diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index f4d4e708a8d..ea79072f521 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -987,13 +987,12 @@ xfs_bwrite( { int error; - bp->b_strat = xfs_bdstrat_cb; bp->b_mount = mp; bp->b_flags |= XBF_WRITE; bp->b_flags &= ~(XBF_ASYNC | XBF_READ); xfs_buf_delwri_dequeue(bp); - xfs_buf_iostrategy(bp); + xfs_bdstrat_cb(bp); error = xfs_buf_iowait(bp); if (error) @@ -1009,7 +1008,6 @@ xfs_bdwrite( { trace_xfs_buf_bdwrite(bp, _RET_IP_); - bp->b_strat = xfs_bdstrat_cb; bp->b_mount = mp; bp->b_flags &= ~XBF_READ; @@ -1044,7 +1042,6 @@ xfs_bioerror( XFS_BUF_UNDONE(bp); XFS_BUF_STALE(bp); - XFS_BUF_CLR_BDSTRAT_FUNC(bp); xfs_biodone(bp); return EIO; @@ -1074,7 +1071,6 @@ xfs_bioerror_relse( XFS_BUF_DONE(bp); XFS_BUF_STALE(bp); XFS_BUF_CLR_IODONE_FUNC(bp); - XFS_BUF_CLR_BDSTRAT_FUNC(bp); if (!(fl & XBF_ASYNC)) { /* * Mark b_error and B_ERROR _both_. @@ -1869,7 +1865,7 @@ xfsbufd( struct xfs_buf *bp; bp = list_first_entry(&tmp, struct xfs_buf, b_list); list_del_init(&bp->b_list); - xfs_buf_iostrategy(bp); + xfs_bdstrat_cb(bp); count++; } if (count) @@ -1916,7 +1912,7 @@ xfs_flush_buftarg( bp->b_flags &= ~XBF_ASYNC; list_add(&bp->b_list, &wait_list); } - xfs_buf_iostrategy(bp); + xfs_bdstrat_cb(bp); } if (wait) { diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h index 814f9e83b51..d072e5ff923 100644 --- a/fs/xfs/linux-2.6/xfs_buf.h +++ b/fs/xfs/linux-2.6/xfs_buf.h @@ -187,7 +187,6 @@ typedef struct xfs_buf { 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; @@ -245,11 +244,6 @@ 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); -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; @@ -321,8 +315,6 @@ extern void xfs_buf_terminate(void); #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)) -- cgit v1.2.3-70-g09d2