Commit 41e5b7ed authored Jun 08, 2015 by Lukas Czerner Committed by Theodore Ts'o Jun 08, 2015

ext4: verify block bitmap even after fresh initialization



If we want to rely on the buffer_verified() flag of the block bitmap
buffer, we have to set it consistently. However currently if we're
initializing uninitialized block bitmap in
ext4_read_block_bitmap_nowait() we're not going to set buffer verified
at all.

We can do this by simply setting the flag on the buffer, but I think
it's actually better to run ext4_validate_block_bitmap() to make sure
that what we did in the ext4_init_block_bitmap() is right.

So run ext4_validate_block_bitmap() even after the block bitmap
initialization. Also bail out early from ext4_validate_block_bitmap() if
we see corrupt bitmap, since we already know it's corrupt and we do not
need to verify that.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

parent 6ccaf3e2

fs/ext4/balloc.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -369,7 +369,7 @@ static void ext4_validate_block_bitmap(struct super_block *sb,
		struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
		struct ext4_sb_info *sbi = EXT4_SB(sb);

		if (buffer_verified(bh))
		if (buffer_verified(bh) \|\| EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
		return;

		ext4_lock_group(sb, block_group);
		@@ -446,7 +446,7 @@ ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
		unlock_buffer(bh);
		if (err)
		ext4_error(sb, "Checksum bad for grp %u", block_group);
		return bh;
		goto verify;
		}
		ext4_unlock_group(sb, block_group);
		if (buffer_uptodate(bh)) {

Admin message