From 5ce14bbcdd1b5d9233d26a1e89faf3a26c820c58 Mon Sep 17 00:00:00 2001 From: Chris Mason Date: Tue, 11 Sep 2007 11:15:39 -0400 Subject: [PATCH] Btrfs: Find and remove dead roots the first time a root is loaded. Dead roots are trees left over after a crash, and they were either in the process of being removed or were waiting to be removed when the box crashed. Before, a search of the entire tree of root pointers was done on mount looking for dead roots. Now, the search is done the first time we load a root. This makes mount faster when there are a large number of snapshots, and it enables the block accounting code to properly update the block counts on the latest root as old versions of the root are reaped after a crash. Signed-off-by: Chris Mason --- fs/btrfs/ctree.h | 3 ++- fs/btrfs/disk-io.c | 9 ++++----- fs/btrfs/root-tree.c | 16 +++++++++++++--- fs/btrfs/transaction.c | 6 ++++-- fs/btrfs/transaction.h | 3 ++- 5 files changed, 25 insertions(+), 12 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 03e1c4ad341b..6d6e94b63803 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -1148,7 +1148,8 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, struct btrfs_root *item); int btrfs_find_last_root(struct btrfs_root *root, u64 objectid, struct btrfs_root_item *item, struct btrfs_key *key); -int btrfs_find_dead_roots(struct btrfs_root *root); +int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid, + struct btrfs_root *latest_root); /* dir-item.c */ int btrfs_insert_dir_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, int name_len, u64 dir, diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 6c953a0e0aa3..4296839eea1a 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -426,6 +426,10 @@ struct btrfs_root *btrfs_read_fs_root(struct btrfs_fs_info *fs_info, return ERR_PTR(ret); } + ret = btrfs_find_dead_roots(fs_info->tree_root, + root->root_key.objectid, root); + BUG_ON(ret); + return root; } @@ -522,11 +526,6 @@ struct btrfs_root *open_ctree(struct super_block *sb) btrfs_read_block_groups(extent_root); fs_info->generation = btrfs_super_generation(disk_super) + 1; - ret = btrfs_find_dead_roots(tree_root); - if (ret) { - mutex_unlock(&fs_info->fs_mutex); - goto fail_tree_root; - } mutex_unlock(&fs_info->fs_mutex); return tree_root; diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c index 402f67821c14..3b5926dfbeba 100644 --- a/fs/btrfs/root-tree.c +++ b/fs/btrfs/root-tree.c @@ -93,7 +93,8 @@ int btrfs_insert_root(struct btrfs_trans_handle *trans, struct btrfs_root return ret; } -int btrfs_find_dead_roots(struct btrfs_root *root) +int btrfs_find_dead_roots(struct btrfs_root *root, u64 objectid, + struct btrfs_root *latest) { struct btrfs_root *dead_root; struct btrfs_item *item; @@ -105,7 +106,7 @@ int btrfs_find_dead_roots(struct btrfs_root *root) struct btrfs_leaf *leaf; int slot; - key.objectid = 0; + key.objectid = objectid; key.flags = 0; btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY); key.offset = 0; @@ -131,15 +132,24 @@ int btrfs_find_dead_roots(struct btrfs_root *root) btrfs_disk_key_to_cpu(&key, &item->key); if (btrfs_key_type(&key) != BTRFS_ROOT_ITEM_KEY) goto next; + + if (key.objectid < objectid) + goto next; + + if (key.objectid > objectid) + break; + ri = btrfs_item_ptr(leaf, slot, struct btrfs_root_item); if (btrfs_root_refs(ri) != 0) goto next; + dead_root = btrfs_read_fs_root_no_radix(root->fs_info, &key); if (IS_ERR(dead_root)) { ret = PTR_ERR(dead_root); goto err; } - ret = btrfs_add_dead_root(dead_root, + + ret = btrfs_add_dead_root(dead_root, latest, &root->fs_info->dead_roots); if (ret) goto err; diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c index 2b15daa3a9f2..29755593de65 100644 --- a/fs/btrfs/transaction.c +++ b/fs/btrfs/transaction.c @@ -239,7 +239,9 @@ struct dirty_root { struct btrfs_root *latest_root; }; -int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list) +int btrfs_add_dead_root(struct btrfs_root *root, + struct btrfs_root *latest, + struct list_head *dead_list) { struct dirty_root *dirty; @@ -247,6 +249,7 @@ int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list) if (!dirty) return -ENOMEM; dirty->root = root; + dirty->latest_root = latest; list_add(&dirty->list, dead_list); return 0; } @@ -412,7 +415,6 @@ static int drop_dirty_roots(struct btrfs_root *tree_root, while(1) { trans = btrfs_start_transaction(tree_root, 1); - ret = btrfs_drop_snapshot(trans, dirty->root); if (ret != -EAGAIN) { break; diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h index e451783a1a4d..4bc328cbb24c 100644 --- a/fs/btrfs/transaction.h +++ b/fs/btrfs/transaction.h @@ -78,7 +78,8 @@ void btrfs_transaction_flush_work(struct btrfs_root *root); void btrfs_transaction_queue_work(struct btrfs_root *root, int delay); void btrfs_init_transaction_sys(void); void btrfs_exit_transaction_sys(void); -int btrfs_add_dead_root(struct btrfs_root *root, struct list_head *dead_list); +int btrfs_add_dead_root(struct btrfs_root *root, struct btrfs_root *latest, + struct list_head *dead_list); int btrfs_defrag_dirty_roots(struct btrfs_fs_info *info); int btrfs_defrag_root(struct btrfs_root *root, int cacheonly); int btrfs_clean_old_snapshots(struct btrfs_root *root); -- 2.20.1