See bug 38663 against RH7.1/e2fsprogs, or 35980 against RH- Wolverine/e2fsprogs. Mount has to read /proc/partitions in one gulp. It doesn't. Failed for me after a hard powerdown (oops) and the resulting fsck-the-world frenzy on startup, before the mount -a. Falure cause is identical (getting out of sync with the text at the 1K boundary), but failure mode not quite so drastic as it doesn't bail out like fsck does. I'll attach a patch tonight when I get the time to put one together. This sucks, but we knew it was coming....
Created attachment 16325 [details] patch to use 16k buffer for /proc/partitions
Created attachment 16326 [details] spec file patch
This problem also exists (in theory) in fdisk.c in util-linux-2.10r. Fdisk has another problem, too, that a quick glance at the source reveals: it never closes the FILE* it got to read /proc/paritions with. I'll submit that as a patch to util-linux with a note to see this bug or the e2fsprogs bug for details. I've left these as normal priority/severity. They may want to be escalated. It's a low frequency occurence bug, but the failure mode can be quite dramatic depending on the circumstances and the partition layout of the individual system affected.
Assigning to util-linux, where mount lives nowadays.
Fixed in util-linux-2.11n-3