On Sun, Mar 16, 2014 at 10:00:30PM -0400, tytso@xxxxxxx wrote:
> On Mon, Mar 17, 2014 at 12:56:59AM +0400, a3at.mail@xxxxxxxxx wrote:
> > After I tested ext4 dev branch (eb3e7abb161ad5), without any xfs-tests complaints,
> > I understand what goes wrong, you have not last version of
> > this patch, the latest is v3.
> > (Actually you have description from last patch, but not the latest changes.)
>
> What I did was to take your v3 version of the patch, and then since
> that patch removed the label failed_mount5, I changed instances of
> failed_mount4a to failed_mount5, just for aesthetic reasons.
/me wonders if it would be easier just to do something like this:
ext4: don't crash when validating block bitmap
If EXT4FS_DEBUG is defined, ext4_validate_block_bitmap is called via
ext4_count_free_clusters before sb->s_group_info is set up. When this
happens, the kernel crashes because group info hasn't been loaded.
Forego marking the group corrupt for now; not setting BH_Verified
means we'll revisit the bitmap if something went wrong.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/ext4/balloc.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 2f35689..b375768 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -355,7 +355,10 @@ void ext4_validate_block_bitmap(struct super_block *sb,
struct buffer_head *bh)
{
ext4_fsblk_t blk;
- struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
+ struct ext4_group_info *grp = NULL;
+
+ if (EXT4_SB(sb)->s_group_info)
+ grp = ext4_get_group_info(sb, block_group);
if (buffer_verified(bh))
return;
@@ -366,14 +369,18 @@ void ext4_validate_block_bitmap(struct super_block *sb,
ext4_unlock_group(sb, block_group);
ext4_error(sb, "bg %u: block %llu: invalid block bitmap",
block_group, blk);
- set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
+ if (grp)
+ set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
+ &grp->bb_state);
return;
}
if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
desc, bh))) {
ext4_unlock_group(sb, block_group);
ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
- set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
+ if (grp)
+ set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT,
+ &grp->bb_state);
return;
}
set_buffer_verified(bh);
--
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
