On Mon, Jul 16, 2018 at 05:13:25PM +0800, Su Yue wrote:
> For big filesystems, there are many items in trees(extent tree
> specially).
> For example, to dump one extent, we usually dump extent tree then pipe
> result to grep. The time-consuming part is that dump tree traverses
> items. And it eats cpu and memory too.
>
> This patch introduces an option '-k u64,u8,u64' for users(developers more
> likely) to appoint a specific key to search and dump, then the path
> from root node down the leaf will be dumped.
> The search of the key costs most time of this way.
>
> Signed-off-by: Su Yue <suy.f...@cn.fujitsu.com>
> ---
> Change log:
> v2:
> Rename btrfs_search_spec_key() to btrfs_search_print_path().
> Rename is_key_spec to is_spec_key_set.
> Move btrfs_search_print_path() after open_ctree(), call it only once.
> Remove duplicate code and replaced with btrfs_print_tree().
> Modify the usage about '-k'.
> All are suggested by Qu Wenruo.
>
> cmds-inspect-dump-tree.c | 41 ++++++++++++++++++++-
> print-tree.c | 77 ++++++++++++++++++++++++++++++++++++++++
> print-tree.h | 2 ++
> 3 files changed, 119 insertions(+), 1 deletion(-)
>
> diff --git a/cmds-inspect-dump-tree.c b/cmds-inspect-dump-tree.c
> index c8acd55a0c3a..80df826af0fd 100644
> --- a/cmds-inspect-dump-tree.c
> +++ b/cmds-inspect-dump-tree.c
> @@ -184,6 +184,21 @@ static u64 treeid_from_string(const char *str, const
> char **end)
> return id;
> }
>
> +static int parse_key(struct btrfs_key *key)
> +{
> +
Extra newline.
> + int ret = sscanf(optarg, "%llu,%hhu,%llu", &key->objectid,
> + &key->type, &key->offset);
Please don't do complex initializations in the declaration block.
And use of the global variable 'optarg' is not good, pass the scanned
string as a parameter.
> + if (ret != 3) {
> + error("error parsing key '%s'\n", optarg);
no "\n" at the end of the string in error(...)
> + ret = -EINVAL;
> + } else {
> + ret = 0;
> + }
> +
> + return ret;
> +}
> +
> const char * const cmd_inspect_dump_tree_usage[] = {
> "btrfs inspect-internal dump-tree [options] device",
> "Dump tree structures from a given device",
> @@ -199,6 +214,7 @@ const char * const cmd_inspect_dump_tree_usage[] = {
> "-u|--uuid print only the uuid tree",
> "-b|--block <block_num> print info from the specified block only",
> "-t|--tree <tree_id> print only tree with the given id (string or
> number)",
> + "-k|--key <u64,u8,u64> search the specific key then print path, must
> with -t(conflicts with others)",
As there are more conflicting options, it would be better to group them
and just put a note about that. The message as you write it does not
provide clear usage instructions.
> "--follow use with -b, to show all children tree blocks
> of <block_num>",
> NULL
> };
> @@ -224,8 +240,10 @@ int cmd_inspect_dump_tree(int argc, char **argv)
> unsigned open_ctree_flags;
> u64 block_only = 0;
> struct btrfs_root *tree_root_scan;
> + struct btrfs_key spec_key = { 0 };
> u64 tree_id = 0;
> bool follow = false;
> + bool is_spec_key_set = false;
>
> /*
> * For debug-tree, we care nothing about extent tree (it's just backref
> @@ -248,10 +266,11 @@ int cmd_inspect_dump_tree(int argc, char **argv)
> { "block", required_argument, NULL, 'b'},
> { "tree", required_argument, NULL, 't'},
> { "follow", no_argument, NULL, GETOPT_VAL_FOLLOW },
> + { "key", required_argument, NULL, 'k'},
> { NULL, 0, NULL, 0 }
> };
>
> - c = getopt_long(argc, argv, "deb:rRut:", long_options, NULL);
> + c = getopt_long(argc, argv, "deb:rRut:k:", long_options, NULL);
> if (c < 0)
> break;
> switch (c) {
> @@ -300,6 +319,12 @@ int cmd_inspect_dump_tree(int argc, char **argv)
> }
> break;
> }
> + case 'k':
> + ret = parse_key(&spec_key);
> + if (ret)
> + exit(1);
> + is_spec_key_set = true;
What if the key is already set?
> + break;
> case GETOPT_VAL_FOLLOW:
> follow = true;
> break;
> @@ -308,6 +333,9 @@ int cmd_inspect_dump_tree(int argc, char **argv)
> }
> }
>
> + if (!tree_id && is_spec_key_set)
> + usage(cmd_inspect_dump_tree_usage);
> +
> if (check_argc_exact(argc - optind, 1))
> usage(cmd_inspect_dump_tree_usage);
>
> @@ -325,6 +353,17 @@ int cmd_inspect_dump_tree(int argc, char **argv)
> goto out;
> }
>
> + if (is_spec_key_set) {
> + root = info->tree_root;
> + if (IS_ERR(root) || !root) {
> + ret = root ? PTR_ERR(root) : -1;
> + error("unable to open %s", argv[optind]);
> + goto out;
> + }
> +
> + btrfs_search_print_path(info, tree_id, &spec_key);
> + goto close_root;
> + }
> if (block_only) {
> root = info->chunk_root;
> leaf = read_tree_block(info, block_only, 0);
> diff --git a/print-tree.c b/print-tree.c
> index a09ecfbb28f0..3868e42d5d29 100644
> --- a/print-tree.c
> +++ b/print-tree.c
> @@ -1459,3 +1459,80 @@ void btrfs_print_tree(struct extent_buffer *eb, int
> follow)
>
> return;
> }
> +
> +void btrfs_search_print_path(struct btrfs_fs_info *fs_info, u64
> root_objectid,
> + struct btrfs_key *skey)
> +{
> + int ret;
> + int level;
> + struct btrfs_root *root;
> + struct btrfs_key key;
> + struct extent_buffer *next;
> + struct extent_buffer *eb;
> + struct btrfs_path path;
> +
> + key.objectid = root_objectid;
> + key.type = BTRFS_ROOT_ITEM_KEY;
> + key.offset = (u64)-1;
> +
> + if (key.objectid == BTRFS_TREE_RELOC_OBJECTID)
> + root = btrfs_read_fs_root_no_cache(fs_info, &key);
> + else
> + root = btrfs_read_fs_root(fs_info, &key);
> +
> + if (IS_ERR(root) || !root) {
> + error("failed to read tree: %lld", key.objectid);
> + return;
> + }
> +
> + btrfs_init_path(&path);
> + ret = btrfs_search_slot(NULL, root, skey, &path, 0, 0);
> + if (ret < 0) {
> + error("error search the key [%llu, %u, %llu] in root %llu",
> + skey->objectid, skey->type, skey->offset, root->objectid);
> + goto out;
> + }
> +
> + if (ret > 0) {
> + if (path.slots[0] > btrfs_header_nritems(path.nodes[0])) {
> + ret = btrfs_next_item(root, &path);
> + if (ret) {
> + error(
> + "error search the key [%llu, %u, %llu] in root %llu, no next key",
> + skey->objectid, skey->type,
> + skey->offset, root->objectid);
> + goto out;
> + }
> + }
> +
> + btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
> + printf("next to search key is [%llu, %u, %llu]\n",
> + key.objectid, key.type, key.offset);
> + }
> +
> + level = btrfs_header_level(root->node);
> + for (; level >= 0 ; level--) {
Why isn't this written as
for (level = btrfs_header_level(root->node); level >= 0; level--) {
?
> + eb = path.nodes[level];
> + next = path.nodes[level - 1];
> +
> + btrfs_print_tree(path.nodes[level], 0);
> +
> + if (level == 0)
> + break;
> + if (btrfs_header_level(next) != btrfs_header_level(eb) - 1) {
> + warning(
> + "eb corrupted: parent bytenr %llu slot %d level
> %d child bytenr %llu level has %d expect %d, skipping the slot",
Unindent strings to the left
> + btrfs_header_bytenr(eb), path.slots[level],
> + btrfs_header_level(eb),
> + btrfs_header_bytenr(next),
> + btrfs_header_level(next),
> + btrfs_header_level(eb) - 1);
> + continue;
> + }
> + }
> +
> +out:
> + if (root_objectid == BTRFS_TREE_RELOC_OBJECTID)
> + btrfs_free_fs_root(root);
> + btrfs_release_path(&path);
> +}
> diff --git a/print-tree.h b/print-tree.h
> index 62667d7f6195..c7694596e0ee 100644
> --- a/print-tree.h
> +++ b/print-tree.h
> @@ -26,4 +26,6 @@ void print_chunk_item(struct extent_buffer *eb, struct
> btrfs_chunk *chunk);
> void print_extent_item(struct extent_buffer *eb, int slot, int metadata);
> void print_objectid(FILE *stream, u64 objectid, u8 type);
> void print_key_type(FILE *stream, u64 objectid, u8 type);
> +void btrfs_search_print_path(struct btrfs_fs_info *info, u64 root_objectid,
> + struct btrfs_key *key);
Newline before #endif please.
> #endif
--
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