From: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx> commit cd84bbbac12a173a381a64c6ec8b76a5277b87b5 upstream. Commit 5d1b1b3f492f ("ext4: fix BUG when calling ext4_error with locked block group") introduces ext4_grp_locked_error to handle unlocking a group in error cases. Otherwise, there is a possibility of a sleep while atomic. However, since 43c73221b3b1 ("ext4: replace BUG_ON with WARN_ON in mb_find_extent()"), mb_find_extent() has contained a ext4_error() call while a group spinlock is held. Replace this with ext4_grp_locked_error. Fixes: 43c73221b3b1 ("ext4: replace BUG_ON with WARN_ON in mb_find_extent()") Cc: <stable@xxxxxxxxxxxxxxx> # 4.14+ Signed-off-by: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx> Reviewed-by: Lukas Czerner <lczerner@xxxxxxxxxx> Reviewed-by: Junxiao Bi <junxiao.bi@xxxxxxxxxx> Link: https://lore.kernel.org/r/20210623232114.34457-1-stephen.s.brennan@xxxxxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/mballoc.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -1574,10 +1574,11 @@ static int mb_find_extent(struct ext4_bu if (ex->fe_start + ex->fe_len > EXT4_CLUSTERS_PER_GROUP(e4b->bd_sb)) { /* Should never happen! (but apparently sometimes does?!?) */ WARN_ON(1); - ext4_error(e4b->bd_sb, "corruption or bug in mb_find_extent " - "block=%d, order=%d needed=%d ex=%u/%d/%d@%u", - block, order, needed, ex->fe_group, ex->fe_start, - ex->fe_len, ex->fe_logical); + ext4_grp_locked_error(e4b->bd_sb, e4b->bd_group, 0, 0, + "corruption or bug in mb_find_extent " + "block=%d, order=%d needed=%d ex=%u/%d/%d@%u", + block, order, needed, ex->fe_group, ex->fe_start, + ex->fe_len, ex->fe_logical); ex->fe_len = 0; ex->fe_start = 0; ex->fe_group = 0;