On Sun, Jul 18, 2010 at 04:38:52PM -0400, Christoph Hellwig wrote: > 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@xxxxxx> looks good. Reviewed-by: Dave Chinner <david@xxxxxxxxxxxxx> -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
