tree c90a31068b55da76f7e99d1d41981c779f918921
parent dc046b10c8b7d4f40befe457acb82340bf8b0699
author Liu Bo <bo.li.liu@oracle.com> 1410325130 +0800
committer Chris Mason <clm@fb.com> 1410986305 -0700

Btrfs: fix loop writing of async reclaim

One of my tests shows that when we really don't have space to reclaim via
flush_space and also run out of space, this async reclaim work loops on adding
itself into the workqueue and keeps writing something to disk according to
iostat's results, and these writes mainly comes from commit_transaction which
writes super_block.  This's unacceptable as it can be bad to disks, especially
memeory storages.

This adds a check to avoid the above situation.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>