On Mon, Oct 29, 2012 at 8:20 PM, Liu Bo <bo.li.liu@xxxxxxxxxx> wrote: > On 10/30/2012 04:06 AM, Mitch Harder wrote: >> On Sat, Oct 27, 2012 at 5:28 AM, Liu Bo <bo.li.liu@xxxxxxxxxx> wrote: >>> This comes from one of btrfs's project ideas, >>> As we defragment files, we break any sharing from other snapshots. >>> The balancing code will preserve the sharing, and defrag needs to grow this >>> as well. >>> >>> Now we're able to fill the blank with this patch, in which we make full use of >>> backref walking stuff. >>> >>> Here is the basic idea, >>> o set the writeback ranges started by defragment with flag EXTENT_DEFRAG >>> o at endio, after we finish updating fs tree, we use backref walking to find >>> all parents of the ranges and re-link them with the new COWed file layout by >>> adding corresponding backrefs. >>> >>> Originally patch by Li Zefan <lizf@xxxxxxxxxxxxxx> >>> Signed-off-by: Liu Bo <bo.li.liu@xxxxxxxxxx> >>> --- >>> v3->v4: >>> - fix duplicated refs bugs detected by mounting with autodefrag, thanks >>> for the bug report from Mitch and Chris. >>> >> >> I'm picking up many WARN_ON messages while testing this patch. >> >> I'm testing a snapshot script that uses kernel git sources along with >> some git manipulations. >> >> The kernel is a 3.6.4 kernel merged with the latest for-linus branch. >> >> I mounted with -o compress-force=lzo,autodefrag. >> >> I also have the second patch in this set (Btrfs: make snapshot-aware >> defrag as a mount option). However, I did not mount with >> 'snap_aware_defrag'. >> >> I did not find any corrupted data, and the partition passes a btrfsck >> without error after these warnings were observed. >> > > Hi Mitch, > > Well, good report, but I don't think it has anything to do with this patch(since you > didn't mount with 'snap_aware_defrag' :) > I've re-run my my testing script with a combination of no compression and lzo compression, combined with no further options, only -o autodefrag, and -o autodefrag,snap_aware_defrag. I only get the WARN_ONs when I run with autodefrag only (no snap_aware_defrag). My logs are clean when I avoid all defrag options, or use both autodefrag and snap_aware_defrag. > After going through the below messages, the bug comes from the space side where we > must have mis-used our reservation somehow. > > So can you show me your script so that I can give it a shot to reproduce locally? > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
