This is a note to let you know that I've just added the patch titled ext4: fix race in ext4_mb_add_n_trim() to the 3.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ext4-fix-race-in-ext4_mb_add_n_trim.patch and it can be found in the queue-3.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f1167009711032b0d747ec89a632a626c901a1ad Mon Sep 17 00:00:00 2001 From: Niu Yawei <yawei.niu@xxxxxxxxx> Date: Fri, 1 Feb 2013 21:31:27 -0500 Subject: ext4: fix race in ext4_mb_add_n_trim() From: Niu Yawei <yawei.niu@xxxxxxxxx> commit f1167009711032b0d747ec89a632a626c901a1ad upstream. In ext4_mb_add_n_trim(), lg_prealloc_lock should be taken when changing the lg_prealloc_list. Signed-off-by: Niu Yawei <yawei.niu@xxxxxxxxx> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ext4/mballoc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -4136,7 +4136,7 @@ static void ext4_mb_add_n_trim(struct ex /* The max size of hash table is PREALLOC_TB_SIZE */ order = PREALLOC_TB_SIZE - 1; /* Add the prealloc space to lg */ - rcu_read_lock(); + spin_lock(&lg->lg_prealloc_lock); list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order], pa_inode_list) { spin_lock(&tmp_pa->pa_lock); @@ -4160,12 +4160,12 @@ static void ext4_mb_add_n_trim(struct ex if (!added) list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list[order]); - rcu_read_unlock(); + spin_unlock(&lg->lg_prealloc_lock); /* Now trim the list to be not more than 8 elements */ if (lg_prealloc_count > 8) { ext4_mb_discard_lg_preallocations(sb, lg, - order, lg_prealloc_count); + order, lg_prealloc_count); return; } return ; Patches currently in stable-queue which might be from yawei.niu@xxxxxxxxx are queue-3.8/ext4-fix-race-in-ext4_mb_add_n_trim.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html