summaryrefslogtreecommitdiff
path: root/virt
diff options
context:
space:
mode:
authorJan Kara <jack@suse.cz>2013-06-04 22:23:41 +0400
committerTheodore Ts'o <tytso@mit.edu>2013-06-04 22:23:41 +0400
commitb0857d309faefaf5443752458e8af1a4b22b3e92 (patch)
treeb6b18b3d41831a205a5f90609abb567fd756e07c /virt
parent2e8fa54e3b48e4ce8c4e9ca4674ffbc973f58be5 (diff)
downloadlinux-b0857d309faefaf5443752458e8af1a4b22b3e92.tar.xz
ext4: defer clearing of PageWriteback after extent conversion
Currently PageWriteback bit gets cleared from put_io_page() called from ext4_end_bio(). This is somewhat inconvenient as extent tree is not fully updated at that time (unwritten extents are not marked as written) so we cannot read the data back yet. This design was dictated by lock ordering as we cannot start a transaction while PageWriteback bit is set (we could easily deadlock with ext4_da_writepages()). But now that we use transaction reservation for extent conversion, locking issues are solved and we can move PageWriteback bit clearing after extent conversion is done. As a result we can remove wait for unwritten extent conversion from ext4_sync_file() because it already implicitely happens through wait_on_page_writeback(). We implement deferring of PageWriteback clearing by queueing completed bios to appropriate io_end and processing all the pages when io_end is going to be freed instead of at the moment ext4_io_end() is called. Reviewed-by: Zheng Liu <wenqing.lz@taobao.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'virt')
0 files changed, 0 insertions, 0 deletions