Commit 28739eea authored May 24, 2011 by Lukas Czerner Committed by Theodore Ts'o May 24, 2011

ext4: protect bb_first_free in ext4_trim_all_free() with group lock



We should protect reading bd_info->bb_first_free with the group lock
because otherwise we might miss some free blocks. This is not a big deal
at all, but the change to do right thing is really simple, so lets do
that.

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

parent 78944086

fs/ext4/mballoc.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -4825,11 +4825,11 @@ ext4_trim_all_free(struct super_block *sb, ext4_group_t group,
		"information for %u", group);
		return ret;
		}

		bitmap = e4b.bd_bitmap;

		ext4_lock_group(sb, group);
		start = (e4b.bd_info->bb_first_free > start) ?
		e4b.bd_info->bb_first_free : start;
		ext4_lock_group(sb, group);

		while (start < max) {
		start = mb_find_next_zero_bit(bitmap, max, start);