Hi Ted,
Could you check this patch?
(2012/08/30 20:16), Akira Fujita wrote:
> mke2fs -m option can set reserved blocks ratio up to 50%.
> But if the last BG is not big enough to support the necessary data
> structures, reserved blocks ratio can exceed 50%
> and we never succeed in e2fsck with that FS.
> This bug happens on ext2, ext3 and ext4.
>
> To fix this, the patch recalculates reserved blocks count
> if FS blocks count is changed in mke2fs because of
> the last BG's size.
>
> Steps to reproduce:
>
> 1. Create a FS which has the overhead for the last BG
> and specify 50 % for reserved blocks ratio
> # mke2fs -m 50 -t ext4 DEV 1025M
>
> mke2fs 1.42.5 (29-Jul-2012)
> warning: 256 blocks unused.
>
> Filesystem label=
> OS type: Linux
> Block size=4096 (log=2)
> Fragment size=4096 (log=2)
> Stride=0 blocks, Stripe width=0 blocks
> 656640 inodes, 2621440 blocks
> 1310848 blocks (50.00%) reserved for the super user
> ~~~~~~~ <-- Reserved blocks exceed 50% of FS blocks count!
>
> 2. e2fsck outputs filesystem corruption
> # e2fsck DEV
>
> e2fsck 1.42.5 (29-Jul-2012)
> Corruption found in superblock. (r_blocks_count = 1310848).
>
> The superblock could not be read or does not describe a correct ext2
> filesystem. If the device is valid and it really contains an ext2
> filesystem (and not swap or ufs or something else), then the superblock
> is corrupt, and you might try running e2fsck with an alternate superblock:
> e2fsck -b 32768 <device>
>
>
> Signed-off-by: Akira Fujita <a-fujita@xxxxxxxxxxxx>
> ---
> lib/ext2fs/initialize.c | 9 +++++++++
> 1 files changed, 9 insertions(+), 0 deletions(-)
> diff --git a/lib/ext2fs/initialize.c b/lib/ext2fs/initialize.c
> index 5a6f8ea..3567722 100644
> --- a/lib/ext2fs/initialize.c
> +++ b/lib/ext2fs/initialize.c
> @@ -101,6 +101,7 @@ errcode_t ext2fs_initialize(const char *name, int flags,
> unsigned reserved_inos;
> char *buf = 0;
> char c;
> + double reserved_ratio;
>
> if (!param || !ext2fs_blocks_count(param))
> return EXT2_ET_INVALID_ARGUMENT;
> @@ -391,6 +392,14 @@ ipg_retry:
> if (rem && (rem < overhead+50)) {
> ext2fs_blocks_count_set(super, ext2fs_blocks_count(super) -
> rem);
> + /*
> + * If blocks count is changed, we need to recalculate
> + * reserved blocks count not to exceed 50%.
> + */
> + reserved_ratio = 100.0 * ext2fs_r_blocks_count(param) /
> + ext2fs_blocks_count(param);
> + ext2fs_r_blocks_count_set(super, reserved_ratio *
> + ext2fs_blocks_count(super) / 100.0);
>
> goto retry;
> }
> --
> 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
>
--
Akira Fujita <a-fujita@xxxxxxxxxxxxx>
The First Fundamental Software Development Group,
Platform Division, NEC Software Tohoku, Ltd.
--
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
