From: Josef Bacik Date: Fri, 24 Jan 2020 14:32:27 +0000 (-0500) Subject: btrfs: hold a ref on fs roots while they're in the radix tree X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=af01d2e53f3343e9f22495e79f07b107374b05a1;p=openwrt%2Fstaging%2Fblogic.git btrfs: hold a ref on fs roots while they're in the radix tree If the root is sitting in the radix tree, we should probably have a ref for the radix tree. Grab a ref on the root when we insert it, and drop it when it gets deleted. Reviewed-by: Nikolay Borisov Signed-off-by: Josef Bacik Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 67e7b0ccdea0..43af9f9b8583 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1513,8 +1513,10 @@ int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info, ret = radix_tree_insert(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid, root); - if (ret == 0) + if (ret == 0) { + btrfs_grab_fs_root(root); set_bit(BTRFS_ROOT_IN_RADIX, &root->state); + } spin_unlock(&fs_info->fs_roots_radix_lock); radix_tree_preload_end(); @@ -3817,6 +3819,8 @@ void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info, spin_lock(&fs_info->fs_roots_radix_lock); radix_tree_delete(&fs_info->fs_roots_radix, (unsigned long)root->root_key.objectid); + if (test_and_clear_bit(BTRFS_ROOT_IN_RADIX, &root->state)) + btrfs_put_fs_root(root); spin_unlock(&fs_info->fs_roots_radix_lock); if (btrfs_root_refs(&root->root_item) == 0)