tree 9c047814f2aaaf0a61a611605a88c3c9f9e3184b
parent bb5574880574fea38c674942cf0360253a2d60fe
author Dmitry Monakhov <dmonakhov@openvz.org> 1348678492 -0400
committer Theodore Ts'o <tytso@mit.edu> 1348678492 -0400

ext4: reimplement uninit extent optimization for move_extent_per_page()

Uninitialized extent may became initialized(parallel writeback task)
at any moment after we drop i_data_sem, so we have to recheck extent's
state after we hold page's lock and i_data_sem.

If we about to change page's mapping we must hold page's lock in order to
serialize other users.

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>