On Fri, Jan 11, 2013 at 06:53:46PM +0800, Zheng Liu wrote: > From: Zheng Liu <wenqing.lz@xxxxxxxxxx> > > After tracking all extent status, we already have a extent cache in memory. > Every time we want to lookup a block mapping, we can first try to lookup it in > extent status tree to avoid a potential disk I/O. > > A new function called ext4_es_lookup_extent is defined to finish this work. > When we try to lookup a block mapping, we always call ext4_map_blocks and/or > ext4_da_map_blocks. So in these functions we first try to lookup a block > mapping in extent status tree. > > CC: Jan kara <jack@xxxxxxx> > CC: "Theodore Ts'o" <tytso@xxxxxxx> > Signed-off-by: Zheng Liu <wenqing.lz@xxxxxxxxxx> Once we apply this this patch, we should be able to remove the the single-entry extent cache in fs/ext4/extents.c --- ext4_ext_put_in_cache(), ext4_ext_put_gap_in_cache(), ext4_ext_in_cache() --- since the extent status tree makes this code redundant (and will do a better job). This would be a good follow up, cleanup patch. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
