tree 25375b739b2e3f65c8dff3d3dd2a78e0724d0f96
parent 06d6cf6959d22037fcec598f4f954db5db3d7356
author Mingming Cao <cmm@us.ibm.com> 1215818851 -0400
committer Theodore Ts'o <tytso@mit.edu> 1215818851 -0400

ext4: Invert lock ordering of page_lock and transaction start in delalloc

With the reverse locking, we need to start a transation before taking
the page lock, so in ext4_da_writepages() we need to break the write-out
into chunks, and restart the journal for each chunck to ensure the
write-out fits in a single transaction.

Updated patch from Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
which fixes delalloc sync hang with journal lock inversion, and address
the performance regression issue.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>