On 3/2/20 2:31 PM, David Sterba wrote:
On Mon, Mar 02, 2020 at 01:47:55PM -0500, Josef Bacik wrote:
We were doing the clear dance for the reloc root after doing the drop of
the reloc root, which means we have a giant window where we could miss
having BTRFS_ROOT_DEAD_RELOC_TREE unset and the reloc_root == NULL.
Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
---
fs/btrfs/relocation.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index e60450c44406..acd21c156378 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2291,18 +2291,19 @@ static int clean_dirty_subvols(struct reloc_control *rc)
list_del_init(&root->reloc_dirty_list);
root->reloc_root = NULL;
- if (reloc_root) {
-
- ret2 = btrfs_drop_snapshot(reloc_root, NULL, 0, 1);
- if (ret2 < 0 && !ret)
- ret = ret2;
- }
/*
* Need barrier to ensure clear_bit() only happens after
* root->reloc_root = NULL. Pairs with have_reloc_root.
*/
smp_wmb();
clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state);
+
+ if (reloc_root) {
+
+ ret2 = btrfs_drop_snapshot(reloc_root, NULL, 0, 1);
+ if (ret2 < 0 && !ret)
+ ret = ret2;
+ }
This reverts fix 1fac4a54374f7ef385938f3c6cf7649c0fe4f6cd that moved if
(reloc_root) before the clear_bit.
Hmm we should probably keep this and move the
if (root->reloc_root)
thing after the
if (!rc || !rc->create_reloc_tree ||
root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
return 0;
to properly fix this. I'll add this and send an updated series. Thanks,
Josef
