Re: [PATCH] Btrfs: fix memory leak when cloning root's node
From: Jan Schmidt <hidden>
Date: 2012-10-25 13:24:00
Hi liubo, On Thu, October 25, 2012 at 15:17 (+0200), Liu Bo wrote:
quoted hunk ↗ jump to hunk
After cloning root's node, we forgot to dec the src's ref which can lead to a memory leak. Signed-off-by: Liu Bo <redacted> --- Jan, Please add this patch to your pull and notice Chris about it :) I didn't get this bug out since I didn't do rmmod yesterday... thanks, fs/btrfs/ctree.c | 9 ++++++--- 1 files changed, 6 insertions(+), 3 deletions(-)diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index eba44b0..2afa585 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c@@ -1261,16 +1261,19 @@ get_old_root(struct btrfs_root *root, u64 time_seq) tm = tree_mod_log_search(root->fs_info, logical, time_seq); if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { + struct extent_buffer *old;
I'd rather put this in the beginning of the function.
+
btrfs_tree_read_unlock(root->node);
free_extent_buffer(root->node);
blocksize = btrfs_level_size(root, old_root->level);
- eb = read_tree_block(root, logical, blocksize, 0);
- if (!eb) {
+ old = read_tree_block(root, logical, blocksize, 0);
+ if (!old) {
pr_warn("btrfs: failed to read tree block %llu from get_old_root\n",
logical);
WARN_ON(1);
} else {
- eb = btrfs_clone_extent_buffer(eb);
+ eb = btrfs_clone_extent_buffer(old);
+ free_extent_buffer(eb);You meant free_extent_buffer(old) here. Otherwise ok. Thanks, -Jan
}
} else if (old_root) {
btrfs_tree_read_unlock(root->node);