Re: [PATCH 2/2] btrfs: pretty print leaked root name

Nikolay Borisov
2020-08-21T07:35:42Z

On 20.08.20 г. 23:00 ч., Josef Bacik wrote:
> I'm a actual human being so am incapable of converting u64 to s64 in my
> head, so add a helper to get the pretty name of a root objectid and use
> that helper to spit out the name for any special roots for leaked roots,
> so I don't have to scratch my head and figure out which root I messed up
> the refs for.
>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
> fs/btrfs/disk-io.c | 8 +++++---
> fs/btrfs/print-tree.c | 37 +++++++++++++++++++++++++++++++++++++
> fs/btrfs/print-tree.h | 1 +
> 3 files changed, 43 insertions(+), 3 deletions(-)
>
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index ac6d6fddd5f4..a7358e0f59de 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -1506,11 +1506,13 @@ void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
> struct btrfs_root *root;
>
> while (!list_empty(&fs_info->allocated_roots)) {
> + const char *name = btrfs_root_name(root->root_key.objectid);
> +
> root = list_first_entry(&fs_info->allocated_roots,
> struct btrfs_root, leak_list);
> - btrfs_err(fs_info, "leaked root %llu-%llu refcount %d",
> - root->root_key.objectid, root->root_key.offset,
> - refcount_read(&root->refs));
> + btrfs_err(fs_info, "leaked root %s%lld-%llu refcount %d",

nit: Won't this string result in some rather awkward looking strings,
such as:

"leaked root ROOT_TREE<objectid>-<offset>..." i.e shouldn't the
(objectid,offset) pair be marked with parentheses?

> + name ? name : "", root->root_key.objectid,
> + root->root_key.offset, refcount_read(&root->refs));
> while (refcount_read(&root->refs) > 1)
> btrfs_put_root(root);
> btrfs_put_root(root);
> diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
> index 61f44e78e3c9..c633aec8973d 100644
> --- a/fs/btrfs/print-tree.c
> +++ b/fs/btrfs/print-tree.c
> @@ -7,6 +7,43 @@
> #include "disk-io.h"
> #include "print-tree.h"
>
> +struct name_map {
> + u64 id;
> + const char *name;
> +};
> +
> +static const struct name_map root_map[] = {
> + { BTRFS_ROOT_TREE_OBJECTID, "ROOT_TREE" },
> + { BTRFS_EXTENT_TREE_OBJECTID, "EXTENT_TREE" },
> + { BTRFS_CHUNK_TREE_OBJECTID, "CHUNK_TREE" },
> + { BTRFS_DEV_TREE_OBJECTID, "DEV_TREE" },
> + { BTRFS_FS_TREE_OBJECTID, "FS_TREE" },
> + { BTRFS_ROOT_TREE_DIR_OBJECTID, "ROOT_TREE_DIR" },
> + { BTRFS_CSUM_TREE_OBJECTID, "CSUM_TREE" },
> + { BTRFS_TREE_LOG_OBJECTID, "TREE_LOG" },
> + { BTRFS_QUOTA_TREE_OBJECTID, "QUOTA_TREE" },
> + { BTRFS_TREE_RELOC_OBJECTID, "TREE_RELOC" },
> + { BTRFS_UUID_TREE_OBJECTID, "UUID_TREE" },
> + { BTRFS_FREE_SPACE_TREE_OBJECTID, "FREE_SPACE_TREE" },
> + { BTRFS_DATA_RELOC_TREE_OBJECTID, "DATA_RELOC_TREE" },
> +};
> +
> +const char *btrfs_root_name(u64 objectid)
> +{
> + int i;
> +
> + if (objectid >= BTRFS_FIRST_FREE_OBJECTID &&
> + objectid <= BTRFS_LAST_FREE_OBJECTID)
> + return NULL;
> +
> + for (i = 0; i < ARRAY_SIZE(root_map); i++) {
> + if (root_map[i].id == objectid)
> + return root_map[i].name;
> + }
> +
> + return NULL;
> +}
> +
> static void print_chunk(struct extent_buffer *eb, struct btrfs_chunk *chunk)
> {
> int num_stripes = btrfs_chunk_num_stripes(eb, chunk);
> diff --git a/fs/btrfs/print-tree.h b/fs/btrfs/print-tree.h
> index e6bb38fd75ad..dffdfa495297 100644
> --- a/fs/btrfs/print-tree.h
> +++ b/fs/btrfs/print-tree.h
> @@ -8,5 +8,6 @@
>
> void btrfs_print_leaf(struct extent_buffer *l);
> void btrfs_print_tree(struct extent_buffer *c, bool follow);
> +const char *btrfs_root_name(u64 objectid);
>
> #endif
>