From 25e293c2a2916b58cdafb8219c0e93d6277762d7 Mon Sep 17 00:00:00 2001 From: Wang Shilong Date: Thu, 26 Dec 2013 13:10:50 +0800 Subject: [PATCH] Btrfs: fix an oops when we fail to merge reloc roots Previously, we will free reloc root memory and then force filesystem to be readonly. The problem is that there may be another thread commiting transaction which will try to access freed reloc root during merging reloc roots process. To keep consistency snapshots shared space, we should allow snapshot finished if possible, so here we don't free reloc root memory. signed-off-by: Wang Shilong Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/relocation.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 277b8e371fa5..9189f9e3c359 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -2311,9 +2311,6 @@ void free_reloc_roots(struct list_head *list) reloc_root = list_entry(list->next, struct btrfs_root, root_list); __del_reloc_root(reloc_root); - free_extent_buffer(reloc_root->node); - free_extent_buffer(reloc_root->commit_root); - kfree(reloc_root); } } @@ -2355,10 +2352,9 @@ int merge_reloc_roots(struct reloc_control *rc) ret = merge_reloc_root(rc, root); if (ret) { - __del_reloc_root(reloc_root); - free_extent_buffer(reloc_root->node); - free_extent_buffer(reloc_root->commit_root); - kfree(reloc_root); + if (list_empty(&reloc_root->root_list)) + list_add_tail(&reloc_root->root_list, + &reloc_roots); goto out; } } else { -- GitLab