Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit b5cb1600 authored by Josef Bacik's avatar Josef Bacik Committed by Chris Mason
Browse files

Btrfs: fix small race with delalloc flushing waitqueue's 



Everytime we start a new flushing thread, we init the waitqueue if there isn't a
flushing thread running.  The problem with this is we check
space_info->flushing, which we clear right before doing a wake_up on the
flushing waitqueue, which causes problems if we init the waitqueue in the middle
of clearing the flushing flagh and calling wake_up.  This is hard to hit, but
the code is wrong anyway, so init the flushing/allocating waitqueue when
creating the space info and let it be.  I haven't seen the panic since I've been
using this patch.  Thanks,

Signed-off-by: default avatarJosef Bacik <josef@redhat.com>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent 28ecb609

fs/btrfs/extent-tree.c

+4 −5
Original line number Diff line number Diff line
@@ -2676,6 +2676,8 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags, 


	INIT_LIST_HEAD(&found->block_groups);

	init_rwsem(&found->groups_sem);

	init_waitqueue_head(&found->flush_wait);

	init_waitqueue_head(&found->allocate_wait);

	spin_lock_init(&found->lock);

	found->flags = flags;

	found->total_bytes = total_bytes;
@@ -2944,12 +2946,10 @@ static void flush_delalloc(struct btrfs_root *root, 


	spin_lock(&info->lock);



	if (!info->flushing) {

	if (!info->flushing)

		info->flushing = 1;

		init_waitqueue_head(&info->flush_wait);

	} else {

	else

		wait = true;

	}



	spin_unlock(&info->lock);
@@ -3011,7 +3011,6 @@ static int maybe_allocate_chunk(struct btrfs_root *root, 
	if (!info->allocating_chunk) {

		info->force_alloc = 1;

		info->allocating_chunk = 1;

		init_waitqueue_head(&info->allocate_wait);

	} else {

		wait = true;

	}