From 13a8a7c8c47e542b3cdb45bec3f431f96af79361 Mon Sep 17 00:00:00 2001 From: "Yan, Zheng" Date: Mon, 21 Sep 2009 15:56:00 -0400 Subject: Btrfs: do not reuse objectid of deleted snapshot/subvol The new back reference format does not allow reusing objectid of deleted snapshot/subvol. So we use ++highest_objectid to allocate objectid for new snapshot/subvol. Now we use ++highest_objectid to allocate objectid for both new inode and new snapshot/subvolume, so this patch removes 'find hole' code in btrfs_find_free_objectid. Signed-off-by: Yan Zheng Signed-off-by: Chris Mason --- fs/btrfs/inode-map.c | 93 +++++++++------------------------------------------- 1 file changed, 15 insertions(+), 78 deletions(-) (limited to 'fs/btrfs/inode-map.c') diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c index 9abbced1123..c56eb590917 100644 --- a/fs/btrfs/inode-map.c +++ b/fs/btrfs/inode-map.c @@ -43,9 +43,10 @@ int btrfs_find_highest_inode(struct btrfs_root *root, u64 *objectid) slot = path->slots[0] - 1; l = path->nodes[0]; btrfs_item_key_to_cpu(l, &found_key, slot); - *objectid = found_key.objectid; + *objectid = max_t(u64, found_key.objectid, + BTRFS_FIRST_FREE_OBJECTID - 1); } else { - *objectid = BTRFS_FIRST_FREE_OBJECTID; + *objectid = BTRFS_FIRST_FREE_OBJECTID - 1; } ret = 0; error: @@ -53,91 +54,27 @@ error: return ret; } -/* - * walks the btree of allocated inodes and find a hole. - */ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 dirid, u64 *objectid) { - struct btrfs_path *path; - struct btrfs_key key; int ret; - int slot = 0; - u64 last_ino = 0; - int start_found; - struct extent_buffer *l; - struct btrfs_key search_key; - u64 search_start = dirid; - mutex_lock(&root->objectid_mutex); - if (root->last_inode_alloc >= BTRFS_FIRST_FREE_OBJECTID && - root->last_inode_alloc < BTRFS_LAST_FREE_OBJECTID) { - *objectid = ++root->last_inode_alloc; - mutex_unlock(&root->objectid_mutex); - return 0; - } - path = btrfs_alloc_path(); - BUG_ON(!path); - search_start = max(search_start, (u64)BTRFS_FIRST_FREE_OBJECTID); - search_key.objectid = search_start; - search_key.type = 0; - search_key.offset = 0; - - start_found = 0; - ret = btrfs_search_slot(trans, root, &search_key, path, 0, 0); - if (ret < 0) - goto error; - while (1) { - l = path->nodes[0]; - slot = path->slots[0]; - if (slot >= btrfs_header_nritems(l)) { - ret = btrfs_next_leaf(root, path); - if (ret == 0) - continue; - if (ret < 0) - goto error; - if (!start_found) { - *objectid = search_start; - start_found = 1; - goto found; - } - *objectid = last_ino > search_start ? - last_ino : search_start; - goto found; - } - btrfs_item_key_to_cpu(l, &key, slot); - if (key.objectid >= search_start) { - if (start_found) { - if (last_ino < search_start) - last_ino = search_start; - if (key.objectid > last_ino) { - *objectid = last_ino; - goto found; - } - } else if (key.objectid > search_start) { - *objectid = search_start; - goto found; - } - } - if (key.objectid >= BTRFS_LAST_FREE_OBJECTID) - break; + if (unlikely(root->highest_objectid < BTRFS_FIRST_FREE_OBJECTID)) { + ret = btrfs_find_highest_inode(root, &root->highest_objectid); + if (ret) + goto out; + } - start_found = 1; - last_ino = key.objectid + 1; - path->slots[0]++; + if (unlikely(root->highest_objectid >= BTRFS_LAST_FREE_OBJECTID)) { + ret = -ENOSPC; + goto out; } - BUG_ON(1); -found: - btrfs_release_path(root, path); - btrfs_free_path(path); - BUG_ON(*objectid < search_start); - mutex_unlock(&root->objectid_mutex); - return 0; -error: - btrfs_release_path(root, path); - btrfs_free_path(path); + + *objectid = ++root->highest_objectid; + ret = 0; +out: mutex_unlock(&root->objectid_mutex); return ret; } -- cgit v1.2.3