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 <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3b6df71..746a9ac 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1007,8 +1007,8 @@
u32 stripesize;
u32 type;
- u64 highest_inode;
- u64 last_inode_alloc;
+
+ u64 highest_objectid;
int ref_cows;
int track_dirty;
u64 defrag_trans_start;
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 16dae12..790f4b6 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -895,8 +895,7 @@
root->fs_info = fs_info;
root->objectid = objectid;
root->last_trans = 0;
- root->highest_inode = 0;
- root->last_inode_alloc = 0;
+ root->highest_objectid = 0;
root->name = NULL;
root->in_sysfs = 0;
root->inode_tree.rb_node = NULL;
@@ -1095,7 +1094,6 @@
struct btrfs_fs_info *fs_info = tree_root->fs_info;
struct btrfs_path *path;
struct extent_buffer *l;
- u64 highest_inode;
u64 generation;
u32 blocksize;
int ret = 0;
@@ -1110,7 +1108,7 @@
kfree(root);
return ERR_PTR(ret);
}
- goto insert;
+ goto out;
}
__setup_root(tree_root->nodesize, tree_root->leafsize,
@@ -1120,39 +1118,30 @@
path = btrfs_alloc_path();
BUG_ON(!path);
ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
- if (ret != 0) {
- if (ret > 0)
- ret = -ENOENT;
- goto out;
+ if (ret == 0) {
+ l = path->nodes[0];
+ read_extent_buffer(l, &root->root_item,
+ btrfs_item_ptr_offset(l, path->slots[0]),
+ sizeof(root->root_item));
+ memcpy(&root->root_key, location, sizeof(*location));
}
- l = path->nodes[0];
- read_extent_buffer(l, &root->root_item,
- btrfs_item_ptr_offset(l, path->slots[0]),
- sizeof(root->root_item));
- memcpy(&root->root_key, location, sizeof(*location));
- ret = 0;
-out:
- btrfs_release_path(root, path);
btrfs_free_path(path);
if (ret) {
- kfree(root);
+ if (ret > 0)
+ ret = -ENOENT;
return ERR_PTR(ret);
}
+
generation = btrfs_root_generation(&root->root_item);
blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
blocksize, generation);
root->commit_root = btrfs_root_node(root);
BUG_ON(!root->node);
-insert:
- if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
+out:
+ if (location->objectid != BTRFS_TREE_LOG_OBJECTID)
root->ref_cows = 1;
- ret = btrfs_find_highest_inode(root, &highest_inode);
- if (ret == 0) {
- root->highest_inode = highest_inode;
- root->last_inode_alloc = highest_inode;
- }
- }
+
return root;
}
diff --git a/fs/btrfs/inode-item.c b/fs/btrfs/inode-item.c
index 6b627c6..fc6f4a7 100644
--- a/fs/btrfs/inode-item.c
+++ b/fs/btrfs/inode-item.c
@@ -177,8 +177,6 @@
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(struct btrfs_inode_item));
- if (ret == 0 && objectid > root->highest_inode)
- root->highest_inode = objectid;
return ret;
}
diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index 9abbced..c56eb59 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -43,9 +43,10 @@
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 @@
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;
+
+ if (unlikely(root->highest_objectid < BTRFS_FIRST_FREE_OBJECTID)) {
+ ret = btrfs_find_highest_inode(root, &root->highest_objectid);
+ if (ret)
+ goto out;
}
- 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;
-
- 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;
}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 81ba665..9e81f31 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3624,9 +3624,6 @@
if (ret != 0)
goto fail;
- if (objectid > root->highest_inode)
- root->highest_inode = objectid;
-
inode->i_uid = current_fsuid();
if (dir && (dir->i_mode & S_ISGID)) {
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index f4a7b62..6e674d7 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -2951,7 +2951,6 @@
struct btrfs_key tmp_key;
struct btrfs_root *log;
struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
- u64 highest_inode;
struct walk_control wc = {
.process_func = process_one_buffer,
.stage = 0,
@@ -3010,11 +3009,6 @@
path);
BUG_ON(ret);
}
- ret = btrfs_find_highest_inode(wc.replay_dest, &highest_inode);
- if (ret == 0) {
- wc.replay_dest->highest_inode = highest_inode;
- wc.replay_dest->last_inode_alloc = highest_inode;
- }
key.offset = found_key.offset - 1;
wc.replay_dest->log_root = NULL;
