On Apr 15, 2008 14:17 +0530, Aneesh Kumar K.V wrote: > On Mon, Apr 14, 2008 at 05:40:59PM -0600, Andreas Dilger wrote: > > On Apr 14, 2008 07:50 -0700, Mingming Cao wrote: > > > On Sat, 2008-04-12 at 22:57 +0200, Andi Kleen wrote: > > > > FYI, a system here running various 2.6.25rc kernels (latest upto rc7-git6) > > > > with longer uptimes suddenly decided to fsck one of its file systems > > > > due to an error after reboot. > > > > > > > > The error causing this was: > > > > > > > > kernel: EXT3-fs error (device dm-0): ext3_valid_block_bitmap: Invalid block bitmap - block_group = 285, block = 9338882 > > > > > > > > detected by the 2.6.25rc7-git6 kernel. > > > > > > > > I don't see any ill effects from it and fsck didn't find anything wrong > > > > so it must have been something spurious in memory only (or fsck > > > > fails to check for this condition, but that is hard to imagine) > > > > > > The ext3_valid_block_bitmap() is to check whether the block or inode > > > bitmap block is marked as "used" in the block group bitmap, to prevent > > > allocating blocks from these system meta data blocks. > > > > Right. > > > > > The error messages seems indicating that one of the block group meta > > > data is corrupted, but I don't why fsck doesn't catch this, Andreas? > > > > It might have been corrupted on read (e.g. bad cable, or bad/wrong > > data read from disk the first time). > > > > The message itself isn't very useful though. It should report what it > > thinks is wrong with the bitmap (e.g. whether block/inode bitmaps are > > unallocated, which/how many itable blocks are unallocated). > > debugfs should help to find these details right ? It isn't always possible to run debugfs on a customer system, and the information would be lost after a reboot or an e2fsck. The e2fsck might even happen automatically after an errors=panic reboot and auto e2fsck. Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
