From 21ca38e7dfa11ca45cef3e6c8a6cb6881c4fdd01 Mon Sep 17 00:00:00 2001 From: Lu Fengqi Date: Tue, 26 Jul 2016 14:26:50 +0800 Subject: [PATCH] btrfs-progs: check: introduce low_memory mode fs_tree check Introduce a new function check_fs_roots_v2() for check fs_tree in low_memory mode. It call check_fs_root_v2() to check fs_root, and call check_root_ref() to check root_ref. Signed-off-by: Lu Fengqi Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- cmds-check.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 100 insertions(+), 6 deletions(-) diff --git a/cmds-check.c b/cmds-check.c index ede612d5..fbd6a201 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -4751,8 +4751,8 @@ static int check_root_ref(struct btrfs_root *root, struct btrfs_key *ref_key, struct btrfs_key key; struct btrfs_root_ref *ref; struct btrfs_root_ref *backref; - char ref_name[BTRFS_NAME_LEN]; - char backref_name[BTRFS_NAME_LEN]; + char ref_name[BTRFS_NAME_LEN] = {0}; + char backref_name[BTRFS_NAME_LEN] = {0}; u64 ref_dirid; u64 ref_seq; u32 ref_namelen; @@ -4827,6 +4827,94 @@ out: return err; } +/* + * Check all fs/file tree in low_memory mode. + * + * 1. for fs tree root item, call check_fs_root_v2() + * 2. for fs tree root ref/backref, call check_root_ref() + * + * Return 0 if no error occurred. + */ +static int check_fs_roots_v2(struct btrfs_fs_info *fs_info) +{ + struct btrfs_root *tree_root = fs_info->tree_root; + struct btrfs_root *cur_root = NULL; + struct btrfs_path *path; + struct btrfs_key key; + struct extent_buffer *node; + unsigned int ext_ref; + int slot; + int ret; + int err = 0; + + ext_ref = btrfs_fs_incompat(fs_info, + BTRFS_FEATURE_INCOMPAT_EXTENDED_IREF); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = BTRFS_FS_TREE_OBJECTID; + key.offset = 0; + key.type = BTRFS_ROOT_ITEM_KEY; + + ret = btrfs_search_slot(NULL, tree_root, &key, path, 0, 0); + if (ret < 0) { + err = ret; + goto out; + } else if (ret > 0) { + err = -ENOENT; + goto out; + } + + while (1) { + node = path->nodes[0]; + slot = path->slots[0]; + btrfs_item_key_to_cpu(node, &key, slot); + if (key.objectid > BTRFS_LAST_FREE_OBJECTID) + goto out; + if (key.type == BTRFS_ROOT_ITEM_KEY && + fs_root_objectid(key.objectid)) { + if (key.objectid == BTRFS_TREE_RELOC_OBJECTID) { + cur_root = btrfs_read_fs_root_no_cache(fs_info, + &key); + } else { + key.offset = (u64)-1; + cur_root = btrfs_read_fs_root(fs_info, &key); + } + + if (IS_ERR(cur_root)) { + error("Fail to read fs/subvol tree: %lld", + key.objectid); + err = -EIO; + goto next; + } + + ret = check_fs_root_v2(cur_root, ext_ref); + err |= ret; + + if (key.objectid == BTRFS_TREE_RELOC_OBJECTID) + btrfs_free_fs_root(cur_root); + } else if (key.type == BTRFS_ROOT_REF_KEY || + key.type == BTRFS_ROOT_BACKREF_KEY) { + ret = check_root_ref(tree_root, &key, node, slot); + err |= ret; + } +next: + ret = btrfs_next_item(tree_root, path); + if (ret > 0) + goto out; + if (ret < 0) { + err = ret; + goto out; + } + } + +out: + btrfs_free_path(path); + return err; +} + static int all_backpointers_checked(struct extent_record *rec, int print_errs) { struct list_head *cur = rec->backrefs.next; @@ -12536,7 +12624,10 @@ int cmd_check(int argc, char **argv) BTRFS_FEATURE_INCOMPAT_NO_HOLES); if (!ctx.progress_enabled) fprintf(stderr, "checking fs roots\n"); - ret = check_fs_roots(root, &root_cache); + if (check_mode == CHECK_MODE_LOWMEM) + ret = check_fs_roots_v2(root->fs_info); + else + ret = check_fs_roots(root, &root_cache); if (ret) goto out; @@ -12546,9 +12637,12 @@ int cmd_check(int argc, char **argv) goto out; fprintf(stderr, "checking root refs\n"); - ret = check_root_refs(root, &root_cache); - if (ret) - goto out; + /* For low memory mode, check_fs_roots_v2 handles root refs */ + if (check_mode != CHECK_MODE_LOWMEM) { + ret = check_root_refs(root, &root_cache); + if (ret) + goto out; + } while (repair && !list_empty(&root->fs_info->recow_ebs)) { struct extent_buffer *eb;