From: Lukas Czerner Date: Tue, 24 May 2011 22:28:07 +0000 (-0400) Subject: ext4: protect bb_first_free in ext4_trim_all_free() with group lock X-Git-Tag: v3.0-rc1~140^2~13 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=28739eea9cd42598b632972f5cc64a458c5d40b3 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 Signed-off-by: "Theodore Ts'o" --- diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 38a11bf79329..396b01f5c4fb 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -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);