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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/xfs_buf_item.c | |
| parent | a64afb057b607c04383ab5fb53c51421ba18c434 (diff) | |
| download | op-kernel-dev-939d723b721eef71060201738653a73443ff4510.zip op-kernel-dev-939d723b721eef71060201738653a73443ff4510.tar.gz | |
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/xfs_buf_item.c')
| -rw-r--r-- | fs/xfs/xfs_buf_item.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index 2a9e4ef..1b09d7a 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -694,7 +694,6 @@ xfs_buf_item_init( */ if (bp->b_mount != mp) bp->b_mount = mp; - XFS_BUF_SET_BDSTRAT_FUNC(bp, xfs_bdstrat_cb); if (XFS_BUF_FSPRIVATE(bp, void *) != NULL) { lip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *); if (lip->li_type == XFS_LI_BUF) { |
