https://bugzilla.kernel.org/show_bug.cgi?id=42723 Theodore Tso <tytso@xxxxxxx> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED CC| |tytso@xxxxxxx Resolution| |PATCH_ALREADY_AVAILABLE --- Comment #8 from Theodore Tso <tytso@xxxxxxx> 2012-10-30 20:55:48 --- I'm pretty sure the bug the user was seeing is the one which was introduced in 3.2, and was fixed by commit b0dd6b70f0fd, which landed in 3.5, and then backported to 3.2.20 and 3.4.3. Birger first saw it in 3.2, and fell back to 3.1.7 where he didn't see it. And the symptoms matched up. So that's almost certainly it. Note: the file system wasn't actually corrupted at all; ext4 was just confused. :-) commit b0dd6b70f0fda17ae9762fbb72d98e40a4f66556 Author: Theodore Ts'o <tytso@xxxxxxx> Date: Thu Jun 7 18:56:06 2012 -0400 ext4: fix the free blocks calculation for ext3 file systems w/ uninit_bg Ext3 filesystems that are converted to use as many ext4 file system features as possible will enable uninit_bg to speed up e2fsck times. These file systems will have a native ext3 layout of inode tables and block allocation bitmaps (as opposed to ext4's flex_bg layout). Unfortunately, in these cases, when first allocating a block in an uninitialized block group, ext4 would incorrectly calculate the number of free blocks in that block group, and then errorneously report that the file system was corrupt: EXT4-fs error (device vdd): ext4_mb_generate_buddy:741: group 30, 32254 clusters in bitmap, 3 This problem can be reproduced via: mke2fs -q -t ext4 -O ^flex_bg /dev/vdd 5g mount -t ext4 /dev/vdd /mnt fallocate -l 4600m /mnt/test The problem was caused by a bone headed mistake in the check to see if a particular metadata block was part of the block group. Many thanks to Kees Cook for finding and bisecting the buggy commit which introduced this bug (commit fd034a84e1, present since v3.2). Reported-by: Sander Eikelenboom <linux@xxxxxxxxxxxxxx> Reported-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> Tested-by: Kees Cook <keescook@xxxxxxxxxxxx> Cc: stable@xxxxxxxxxx -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are watching the assignee of the bug. -- 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
