Hi,

I'm having a system where I run ext4 -> LVM -> dm-cache (on the whole disk, so an LVM on top of the dm-cache volume again) -> LVM -> md (RAID-6). It's been reliable over the past few years, but suddenly, I started getting reports of corruption on /, so I restarted. A few volumes were ripe with various forms of corruption, mostly double-cloned blocks, so I did touch /forcefsck, let it fix everything, and upgraded to 4.10.0.

However, this morning, it happened again:

[60084.371367] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm tar: deleted inode referenced: 1213330
[60084.387140] Aborting journal on device dm-27-8.
[60084.397323] EXT4-fs (dm-27): Remounting filesystem read-only
[60084.397344] EXT4-fs error (device dm-27): ext4_journal_check_start:56: Detected aborted journal
[60084.397346] EXT4-fs (dm-27): Remounting filesystem read-only
[60097.051975] EXT4-fs warning (device dm-27): dx_probe:751: inode #1064698: comm tar: Unrecognised inode hash code 16
[60097.062757] EXT4-fs warning (device dm-27): dx_probe:856: inode #1064698: comm tar: Corrupt directory, running e2fsck is recommended
[60097.082758] EXT4-fs warning (device dm-27): dx_probe:751: inode #1064718: comm tar: Unrecognised inode hash code 32
[60097.093544] EXT4-fs warning (device dm-27): dx_probe:856: inode #1064718: comm tar: Corrupt directory, running e2fsck is recommended
[60097.397083] EXT4-fs warning (device dm-27): dx_probe:751: inode #1064533: comm tar: Unrecognised inode hash code 16
[60097.407843] EXT4-fs warning (device dm-27): dx_probe:856: inode #1064533: comm tar: Corrupt directory, running e2fsck is recommended
[60097.508058] EXT4-fs error (device dm-27): ext4_lookup:1604: inode #1064009: comm tar: 'smp-cps.h' linked to parent dir
[60111.315406] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1857201
[60111.331194] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1857199
[60111.351443] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1857208
[60111.371866] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1857203
[60111.392354] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1858416
[60111.412458] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1859508
[60111.432691] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1857207
[60111.453250] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1857205
[60111.473949] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1857211
[60111.494393] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1840154: comm tar: deleted inode referenced: 1857209
[60118.772735] EXT4-fs error: 353 callbacks suppressed
[60118.777828] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1857460
[60118.798438] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1857457
[60118.818908] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1857459
[60118.841219] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1858615
[60118.861083] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1857461
[60118.881539] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1858531
[60118.901990] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1859518
[60118.922453] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1858554
[60118.942455] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1858581
[60118.962787] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1845428: comm tar: deleted inode referenced: 1858586
[69012.993067] EXT4-fs error: 215 callbacks suppressed
[69012.998143] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[69013.016942] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[69013.037263] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[69013.057815] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[69013.077731] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[69013.098168] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[69013.118604] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[69013.139101] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[69013.158520] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[69013.178888] EXT4-fs error (device dm-27): ext4_lookup:1611: inode #1188111: comm find: deleted inode referenced: 1213330
[79334.333925] exim4[12198]: segfault at 7ffdc324fe1c ip 00007fc7b1990d3e sp 00007ffdc324fd60 error 6 in libc-2.24.so[7fc7b194a000+195000]

(dm-27 is my root volume.)

Rough timeline of kernels:

Dec 12: Upgraded from 4.9.0-rc2 to 4.9.0
Feb 13: Upgraded from 4.9.0 to to 4.9.9
Feb 23: Corruption detected (by nightly backup), upgraded to 4.10.0
Feb 24: Corruption detected again

It would seem likely that something happened between 4.9.0 and 4.9.9, but I haven't read the logs. I'll be downgrading to 4.9.0 again to see if that helps.