No, it isn't gone after all, it just happened again:
Jun 13 15:20:37 oberon kernel: [117379.592167] EXT4-fs error (device dm-1): ext4_mb_generate_buddy:756: group 1, block bitmap and bg descriptor inconsistent: 19382 vs 19381 free clusters Jun 13 15:20:37 oberon kernel: [117379.592903] Aborting journal on device dm-1-8. Jun 13 15:20:37 oberon kernel: [117379.593659] EXT4-fs (dm-1): Remounting filesystem read-only
$ uname -a Linux oberon 3.13.0-54-generic #91-Ubuntu SMP Tue May 26 19:15:08 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
No, it isn't gone after all, it just happened again:
Jun 13 15:20:37 oberon kernel: [117379.592167] EXT4-fs error (device dm-1): ext4_mb_ generate_ buddy:756: group 1, block bitmap and bg descriptor inconsistent: 19382 vs 19381 free clusters
Jun 13 15:20:37 oberon kernel: [117379.592903] Aborting journal on device dm-1-8.
Jun 13 15:20:37 oberon kernel: [117379.593659] EXT4-fs (dm-1): Remounting filesystem read-only
$ uname -a
Linux oberon 3.13.0-54-generic #91-Ubuntu SMP Tue May 26 19:15:08 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux