Bcache failures are nasty, because they leave a mix of old and new data on the disk. In this case, there was very little dirty data, but of course the tree roots were dirty and out-of-sync.
fileserver:/usr/src/btrfs-progs# ./btrfs --version Btrfs v3.18.2 kernel version 3.18 [ 572.573566] BTRFS info (device bcache0): enabling auto recovery [ 572.573619] BTRFS info (device bcache0): disk space caching is enabled [ 574.266055] BTRFS (device bcache0): parent transid verify failed on 7567956930560 wanted 613690 found 613681 [ 574.276952] BTRFS (device bcache0): parent transid verify failed on 7567956930560 wanted 613690 found 613681 [ 574.277008] BTRFS: failed to read tree root on bcache0 [ 574.277187] BTRFS (device bcache0): parent transid verify failed on 7567956930560 wanted 613690 found 613681 [ 574.277356] BTRFS (device bcache0): parent transid verify failed on 7567956930560 wanted 613690 found 613681 [ 574.277398] BTRFS: failed to read tree root on bcache0 [ 574.285955] BTRFS (device bcache0): parent transid verify failed on 7567965720576 wanted 613689 found 613694 [ 574.298741] BTRFS (device bcache0): parent transid verify failed on 7567965720576 wanted 613689 found 610499 [ 574.298804] BTRFS: failed to read tree root on bcache0 [ 575.047079] BTRFS (device bcache0): bad tree block start 0 7567954464768 [ 575.111495] BTRFS (device bcache0): parent transid verify failed on 7567954464768 wanted 613688 found 613685 [ 575.111559] BTRFS: failed to read tree root on bcache0 [ 575.121749] BTRFS (device bcache0): bad tree block start 0 7567954214912 [ 575.131803] BTRFS (device bcache0): parent transid verify failed on 7567954214912 wanted 613687 found 613680 [ 575.131866] BTRFS: failed to read tree root on bcache0 [ 575.180101] BTRFS: open_ctree failed all the btrfs tools throw up their hands with similar errors: ileserver:/usr/src/btrfs-progs# btrfs restore /dev/bcache0 -l parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 Ignoring transid failure Couldn't setup extent tree Couldn't setup device tree Could not open root, trying backup super parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 Ignoring transid failure Couldn't setup extent tree Couldn't setup device tree Could not open root, trying backup super parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 Ignoring transid failure Couldn't setup extent tree Couldn't setup device tree Could not open root, trying backup super fileserver:/usr/src/btrfs-progs# ./btrfsck --repair /dev/bcache0 --init-extent-tree enabling repair mode parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 Ignoring transid failure Couldn't setup extent tree Couldn't setup device tree Couldn't open file system Annoyingly: # ./btrfs-image -c9 -t4 -s -w /dev/bcache0 /tmp/test.out parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 parent transid verify failed on 7567956930560 wanted 613690 found 613681 Ignoring transid failure Couldn't setup extent tree Open ctree failed create failed (Success) So I can't even send an image for people to look at. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html