On 2018/10/23 下午5:41, Su Yue wrote:
> From: Su Yanjun <suyj.fnst@xxxxxxxxxxxxxx>
>
> It may cost more time to search all extent data of correspond files but
> should not influence total speed too much cause that only corrupted
> extent items are participated in.
Sorry, I didn't really get the point of the modification from the commit
message.
Would you please explain the purpose of this patch first?
Thanks,
Qu
>
> Signed-off-by: Su Yanjun <suyj.fnst@xxxxxxxxxxxxxx>
> ---
> check/main.c | 110 ++++++++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 92 insertions(+), 18 deletions(-)
>
> diff --git a/check/main.c b/check/main.c
> index bd1f322e0f12..90d9fd570287 100644
> --- a/check/main.c
> +++ b/check/main.c
> @@ -7015,6 +7015,89 @@ out:
> return ret ? ret : nr_del;
> }
>
> +/*
> + * Based extent backref item, we find all file extent items in the fs tree. By
> + * the info we can rebuild the extent backref item
> + */
> +static int __find_possible_backrefs(struct btrfs_root *root,
> + u64 owner, u64 offset, u64 bytenr, u64 *refs_ret,
> + u64 *bytes_ret)
> +{
> + int ret = 0;
> + struct btrfs_path path;
> + struct btrfs_key key;
> + struct btrfs_key found_key;
> + struct btrfs_file_extent_item *fi;
> + struct extent_buffer *leaf;
> + u64 backref_offset, disk_bytenr;
> + int slot;
> +
> + btrfs_init_path(&path);
> +
> + key.objectid = owner;
> + key.type = BTRFS_INODE_ITEM_KEY;
> + key.offset = 0;
> +
> + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
> + if (ret > 0)
> + ret = -ENOENT;
> + if (ret) {
> + btrfs_release_path(&path);
> + return ret;
> + }
> +
> + btrfs_release_path(&path);
> +
> + key.objectid = owner;
> + key.type = BTRFS_EXTENT_DATA_KEY;
> + key.offset = 0;
> +
> + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
> + if (ret < 0) {
> + btrfs_release_path(&path);
> + return ret;
> + }
> +
> + while (1) {
> + leaf = path.nodes[0];
> + slot = path.slots[0];
> +
> + if (slot >= btrfs_header_nritems(leaf)) {
> + ret = btrfs_next_leaf(root, &path);
> + if (ret) {
> + if (ret > 0)
> + ret = 0;
> + break;
> + }
> +
> + leaf = path.nodes[0];
> + slot = path.slots[0];
> + }
> +
> + btrfs_item_key_to_cpu(leaf, &found_key, slot);
> + if ((found_key.objectid != owner) ||
> + (found_key.type != BTRFS_EXTENT_DATA_KEY))
> + break;
> +
> + fi = btrfs_item_ptr(leaf, slot,
> + struct btrfs_file_extent_item);
> +
> + backref_offset = found_key.offset -
> + btrfs_file_extent_offset(leaf, fi);
> + disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
> + *bytes_ret = btrfs_file_extent_disk_num_bytes(leaf,
> + fi);
> + if ((disk_bytenr == bytenr) &&
> + (backref_offset == offset)) {
> + (*refs_ret)++;
> + }
> + path.slots[0]++;
> + }
> +
> + btrfs_release_path(&path);
> + return ret;
> +}
> +
> static int find_possible_backrefs(struct btrfs_fs_info *info,
> struct btrfs_path *path,
> struct cache_tree *extent_cache,
> @@ -7024,9 +7107,9 @@ static int find_possible_backrefs(struct btrfs_fs_info *info,
> struct extent_backref *back, *tmp;
> struct data_backref *dback;
> struct cache_extent *cache;
> - struct btrfs_file_extent_item *fi;
> struct btrfs_key key;
> u64 bytenr, bytes;
> + u64 refs;
> int ret;
>
> rbtree_postorder_for_each_entry_safe(back, tmp,
> @@ -7054,24 +7137,15 @@ static int find_possible_backrefs(struct btrfs_fs_info *info,
> if (IS_ERR(root))
> return PTR_ERR(root);
>
> - key.objectid = dback->owner;
> - key.type = BTRFS_EXTENT_DATA_KEY;
> - key.offset = dback->offset;
> - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
> - if (ret) {
> - btrfs_release_path(path);
> - if (ret < 0)
> - return ret;
> - /* Didn't find it, we can carry on */
> - ret = 0;
> + refs = 0;
> + bytes = 0;
> + ret = __find_possible_backrefs(root, dback->owner,
> + dback->offset, rec->start, &refs, &bytes);
> + if (ret)
> continue;
> - }
>
> - fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
> - struct btrfs_file_extent_item);
> - bytenr = btrfs_file_extent_disk_bytenr(path->nodes[0], fi);
> - bytes = btrfs_file_extent_disk_num_bytes(path->nodes[0], fi);
> - btrfs_release_path(path);
> + bytenr = rec->start;
> +
> cache = lookup_cache_extent(extent_cache, bytenr, 1);
> if (cache) {
> struct extent_record *tmp;
> @@ -7090,7 +7164,7 @@ static int find_possible_backrefs(struct btrfs_fs_info *info,
> continue;
> }
>
> - dback->found_ref += 1;
> + dback->found_ref += refs;
> dback->disk_bytenr = bytenr;
> dback->bytes = bytes;
>
>
