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| author | Christoph Hellwig <hch@infradead.org> | 2010-07-20 17:51:16 +1000 |
|---|---|---|
| committer | Alex Elder <aelder@sgi.com> | 2010-07-26 13:16:52 -0500 |
| commit | 939d723b721eef71060201738653a73443ff4510 (patch) | |
| tree | 3965391cebe9f1e0c1acb0b394c50c1b83312aa3 /fs/xfs/linux-2.6/xfs_buf.c | |
| parent | a64afb057b607c04383ab5fb53c51421ba18c434 (diff) | |
| download | kernel_samsung_espresso10-939d723b721eef71060201738653a73443ff4510.zip kernel_samsung_espresso10-939d723b721eef71060201738653a73443ff4510.tar.gz kernel_samsung_espresso10-939d723b721eef71060201738653a73443ff4510.tar.bz2 | |
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 <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/linux-2.6/xfs_buf.c')
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_buf.c | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index f4d4e70..ea79072 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) { |