From: Zheng Liu Date: Tue, 25 Nov 2014 16:44:37 +0000 (-0500) Subject: ext4: cache extent hole in extent status tree for ext4_da_map_blocks() X-Git-Tag: omap-for-v3.19/fixes-rc1~116^2~18 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2f8e0a7c6c89f850ebd5d6c0b9a08317030d1b89;p=pandora-kernel.git ext4: cache extent hole in extent status tree for ext4_da_map_blocks() Currently extent status tree doesn't cache extent hole when a write looks up in extent tree to make sure whether a block has been allocated or not. In this case, we don't put extent hole in extent cache because later this extent might be removed and a new delayed extent might be added back. But it will cause a defect when we do a lot of writes. If we don't put extent hole in extent cache, the following writes also need to access extent tree to look at whether or not a block has been allocated. It brings a cache miss. This commit fixes this defect. Also if the inode doesn't have any extent, this extent hole will be cached as well. Cc: Andreas Dilger Signed-off-by: Zheng Liu Signed-off-by: Jan Kara Signed-off-by: Theodore Ts'o --- Reading git-diff-tree failed