Commits
Li Zefan committed 2a0f7f57699
Btrfs: fix recursive auto-defrag Follow those steps: # mount -o autodefrag /dev/sda7 /mnt # dd if=/dev/urandom of=/mnt/tmp bs=200K count=1 # sync # dd if=/dev/urandom of=/mnt/tmp bs=8K count=1 conv=notrunc and then it'll go into a loop: writeback -> defrag -> writeback ... It's because writeback writes [8K, 200K] and then writes [0, 8K]. I tried to make writeback know if the pages are dirtied by defrag, but the patch was a bit intrusive. Here I simply set writeback_index when we defrag a file. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>