filesystem errors

[Andras Simon]

Recently, I noticed messages like the following on two laptops with
very different hardware, but both running Fedora 21, updated daily:

/var/log/messages-20150216:Feb 12 18:47:36 lenov kernel:
[181055.262390] EXT4-fs error (device sda3): __ext4_new_inode:1010:
comm NetworkManager: failed to insert inode 262402: doubly allocated?
/var/log/messages-20150224:Feb 23 21:54:30 lenov kernel:
[510707.869736] EXT4-fs error (device sda3):
ext4_mb_generate_buddy:757: group 34, block bitmap and bg descriptor
inconsistent: 15366 vs 15373 free clusters

On both machines, the affected partition is the root partition. The
problem is bad enough that it needs an fsck from a rescue disk.
smartctl -a /dev/sda doesn't signal any error, but the disks failing
on different machines simultaneously is unlikely anyway, especially
that this happened  sometime in January, too, also with the same
laptops, also roughly at the same time.

I don't know if this is relevant, but both laptops are hibernated usually.

Has anyone else noticed something like this?

Andras