On 24. 12. 18 14:02, Qu Wenruo wrote:
btrfs check --readonly output please.
btrfs check --readonly is always the most reliable and detailed output
for any possible recovery.
This is very weird because it prints only:
ERROR: cannot open file system
I've tried also "btrfs check -r 75152310272" but it only says:
parent transid verify failed on 75152310272 wanted 2488742 found 2488741
parent transid verify failed on 75152310272 wanted 2488742 found 2488741
Ignoring transid failure
ERROR: cannot open file system
I've tried that because:
backup 3:
backup_tree_root: 75152310272 gen: 2488741 level: 1
Also kernel message for the mount failure could help.
Sorry, my fault, I should start from this point:
Dec 23 21:59:07 tisc5 kernel: [10319.442615] BTRFS: device fsid
be557007-42c9-4079-be16-568997e94cd9 devid 1 transid 2488742 /dev/loop0
Dec 23 22:00:49 tisc5 kernel: [10421.167028] BTRFS info (device loop0):
disk space caching is enabled
Dec 23 22:00:49 tisc5 kernel: [10421.167034] BTRFS info (device loop0):
has skinny extents
Dec 23 22:00:50 tisc5 kernel: [10421.807564] BTRFS critical (device
loop0): corrupt node: root=1 block=75150311424 slot=245, invalid NULL
node pointer
Dec 23 22:00:50 tisc5 kernel: [10421.807653] BTRFS error (device loop0):
failed to read block groups: -5
Dec 23 22:00:50 tisc5 kernel: [10421.877001] BTRFS error (device loop0):
open_ctree failed
So i tried to do:
1) btrfs inspect-internal dump-super (with the snippet posted above)
2) btrfs inspect-internal dump-tree -b 75150311424
And it showed (header + snippet for items 243-248):
node 75150311424 level 1 items 249 free 244 generation 2488741 owner 2
fs uuid be557007-42c9-4079-be16-568997e94cd9
chunk uuid dbe69c7e-2d50-4001-af31-148c5475b48b
...
key (14799519744 EXTENT_ITEM 4096) block 233423224832 (14247023) gen
2484894
key (14811271168 EXTENT_ITEM 135168) block 656310272 (40058) gen 2488049
key (1505328190277054464 UNKNOWN.4 366981796979539968) block 0 (0) gen 0
key (0 UNKNOWN.0 1419267647995904) block 6468220747776 (394788864)
gen 7786775707648
key (12884901888 EXTENT_ITEM 24576) block 816693248 (49847) gen 2484931
key (14902849536 EXTENT_ITEM 131072) block 75135844352 (4585928) gen
2488739
I looked at that numbers quite a while (also in hex) trying to figure
out what has happened (bit flips (it was on SSD), byte shifts (I
suspected bad CPU also ... because it has died after 2 months from
that)) and tried to guess "correct" values for that items ... but no idea:-(
So this why I have asked about that log_root and whether there is a
chance to "log-replay things":-)
Thanks
M.
