Hello,
I have noticed some files on my workstation home FS (ext4) having very
suspicious timestamp values. This has probably started happening in April when
the machine was running v4.4.3, but the last occurence is from a week ago on
v4.5.6.
The corruption looks like nonsensical atime and/or mtime seconds values (see
below). At the same time, the nanosecond portion of a corrupted time is always
zero. In fact, the nanoseconds for mtime are all zeros for all of the affected
files, even if the seconds part of mtime looks OK.
I can't confidently claim this is an ext4 bug, but it seems likely (there were
no HW failures, power cuts, oopses etc. and fsck found no errors). I would be
glad to debug this further, but currently I have no idea how to reproduce the
corruption. Any hints are welcome.
Best regards,
Tomáš Trnka
debugfs: stat Administrace/pip/pip-krb5-storage.pcap
Inode: 38933641 Type: regular Mode: 0644 Flags: 0x80000
Generation: 2251791665 Version: 0x00000000:00000001
User: 395845 Group: 2001 Size: 802806
File ACL: 0 Directory ACL: 0
Links: 1 Blockcount: 1568
Fragment: Address: 0 Number: 0 Size: 0
ctime: 0x572335f2:32d79df0 -- Fri Apr 29 12:22:42 2016
atime: 0xf9b65000:00000000 -- Thu Oct 5 09:00:16 2102
mtime: 0x57233597:00000000 -- Fri Apr 29 12:21:11 2016
crtime: 0x572335f2:1d9f6f84 -- Fri Apr 29 12:22:42 2016
Size of extra inode fields: 32
Extended attributes stored in inode body:
selinux = "unconfined_u:object_r:user_home_t:s0\000" (37)
EXTENTS:
(0-195):155943077-155943272
debugfs: inode_dump Administrace/pip/pip-krb5-storage.pcap
0000 a481 450a f63f 0c00 0050 b6f9 f235 2357 ..E..?...P...5#W
0020 9735 2357 0000 0000 d107 0100 2006 0000 .5#W........ ...
0040 0000 0800 0100 0000 0af3 0100 0400 0000 ................
0060 0000 0000 0000 0000 c400 0000 a580 4b09 ..............K.
0100 0000 0000 0000 0000 0000 0000 0000 0000 ................
*
0140 0000 0000 319d 3786 0000 0000 0000 0000 ....1.7.........
0160 0000 0000 0000 0000 0600 0000 0000 0000 ................
0200 2000 0000 f09d d732 0000 0000 0000 0000 ......2........
0220 f235 2357 846f 9f1d 0000 0000 0000 0000 .5#W.o..........
0240 0000 02ea 0706 3400 0000 0000 2500 0000 ......4.....%...
0260 0000 0000 7365 6c69 6e75 7800 0000 0000 ....selinux.....
0300 0000 0000 0000 0000 0000 0000 0000 0000 ................
0320 0000 0000 0000 0000 756e 636f 6e66 696e ........unconfin
0340 6564 5f75 3a6f 626a 6563 745f 723a 7573 ed_u:object_r:us
0360 6572 5f68 6f6d 655f 743a 7330 0000 0000 er_home_t:s0....
debugfs: stat tmp/RDP-log.csv
Inode: 39191637 Type: regular Mode: 0755 Flags: 0x80000
Generation: 2606527817 Version: 0x00000000:00000001
User: 395845 Group: 2001 Size: 749186
File ACL: 166150131 Directory ACL: 0
Links: 1 Blockcount: 1472
Fragment: Address: 0 Number: 0 Size: 0
ctime: 0x53c77ea3:78c876a4 -- Thu Jul 17 09:43:31 2014
atime: 0x5773d316:494a0854 -- Wed Jun 29 15:54:30 2016
mtime: 0x987df1f8:00000000 -- Fri Jan 27 01:06:16 2051
crtime: 0x53c77ea0:4e193034 -- Thu Jul 17 09:43:28 2014
Size of extra inode fields: 32
EXTENTS:
(0-182):11657216-11657398
debugfs: inode_dump tmp/RDP-log.csv
0000 ed81 450a 826e 0b00 16d3 7357 a37e c753 ..E..n....sW.~.S
0020 f8f1 7d98 0000 0000 d107 0100 c005 0000 ..}.............
0040 0000 0800 0100 0000 0af3 0100 0400 0000 ................
0060 0000 0000 0000 0000 b700 0000 00e0 b100 ................
0100 0000 0000 0000 0000 0000 0000 0000 0000 ................
*
0140 0000 0000 4975 5c9b f33f e709 0000 0000 ....Iu\..?......
0160 0000 0000 0000 0000 0600 0000 0000 0000 ................
0200 2000 0000 a476 c878 0000 0000 5408 4a49 ....v.x....T.JI
0220 a07e c753 3430 194e 0000 0000 0000 0000 .~.S40.N........
0240 0000 0000 0000 0000 0000 0000 0000 0000 ................
*
debugfs: stat openmpi/kraken16.xml
Inode: 48117428 Type: regular Mode: 0640 Flags: 0x80000
Generation: 3888286010 Version: 0x00000000:00000001
User: 395845 Group: 2001 Size: 32693
File ACL: 0 Directory ACL: 0
Links: 1 Blockcount: 64
Fragment: Address: 0 Number: 0 Size: 0
ctime: 0x5763eb3c:45901c0c -- Fri Jun 17 14:21:16 2016
atime: 0x82779900:00000000 -- Fri May 13 07:07:12 2039
mtime: 0x5763eb07:00000000 -- Fri Jun 17 14:20:23 2016
crtime: 0x5763eb3c:42b3ae24 -- Fri Jun 17 14:21:16 2016
Size of extra inode fields: 32
Extended attributes stored in inode body:
selinux = "unconfined_u:object_r:user_home_t:s0\000" (37)
EXTENTS:
(0-7):192521632-192521639
debugfs: inode_dump openmpi/kraken16.xml
0000 a081 450a b57f 0000 0099 7782 3ceb 6357 ..E.......w.<.cW
0020 07eb 6357 0000 0000 d107 0100 4000 0000 ..cW........@...
0040 0000 0800 0100 0000 0af3 0100 0400 0000 ................
0060 0000 0000 0000 0000 0800 0000 a0a5 790b ..............y.
0100 0000 0000 0000 0000 0000 0000 0000 0000 ................
*
0140 0000 0000 3a89 c2e7 0000 0000 0000 0000 ....:...........
0160 0000 0000 0000 0000 0600 0000 0000 0000 ................
0200 2000 0000 0c1c 9045 0000 0000 0000 0000 ......E........
0220 3ceb 6357 24ae b342 0000 0000 0000 0000 <.cW$..B........
0240 0000 02ea 0706 3400 0000 0000 2500 0000 ......4.....%...
0260 0000 0000 7365 6c69 6e75 7800 0000 0000 ....selinux.....
0300 0000 0000 0000 0000 0000 0000 0000 0000 ................
0320 0000 0000 0000 0000 756e 636f 6e66 696e ........unconfin
0340 6564 5f75 3a6f 626a 6563 745f 723a 7573 ed_u:object_r:us
0360 6572 5f68 6f6d 655f 743a 7330 0000 0000 er_home_t:s0....