Yan, Zheng
2009-Aug-25 14:39 UTC
[PATCH 3/4] do not reuse objectid of deleted snapshot/subvol
The new back refernece format does not allow reusing objectid of
deleted snapshot/subvol. So use ++highest_objectid to allocate
objectid for new snapshot/subvol.
Since we use ++highest_objectid to allocate objectid for both
new inode and new snapshot/subvol, This patch also removes
''find hole'' code in btrfs_find_free_objectid.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
---
diff -urp 3/fs/btrfs/ctree.h 4/fs/btrfs/ctree.h
--- 3/fs/btrfs/ctree.h 2009-08-24 10:38:34.280386024 +0800
+++ 4/fs/btrfs/ctree.h 2009-08-24 10:39:12.200349458 +0800
@@ -998,8 +998,8 @@ struct btrfs_root {
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 -urp 3/fs/btrfs/disk-io.c 4/fs/btrfs/disk-io.c
--- 3/fs/btrfs/disk-io.c 2009-08-24 10:36:43.009349000 +0800
+++ 4/fs/btrfs/disk-io.c 2009-08-24 10:39:12.202348481 +0800
@@ -893,8 +893,7 @@ static int __setup_root(u32 nodesize, u3
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;
@@ -1093,7 +1092,6 @@ struct btrfs_root *btrfs_read_fs_root_no
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;
@@ -1108,7 +1106,7 @@ struct btrfs_root *btrfs_read_fs_root_no
kfree(root);
return ERR_PTR(ret);
}
- goto insert;
+ goto out;
}
__setup_root(tree_root->nodesize, tree_root->leafsize,
@@ -1118,39 +1116,30 @@ struct btrfs_root *btrfs_read_fs_root_no
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 -urp 3/fs/btrfs/inode.c 4/fs/btrfs/inode.c
--- 3/fs/btrfs/inode.c 2009-08-24 10:38:34.284098975 +0800
+++ 4/fs/btrfs/inode.c 2009-08-24 10:39:12.205349181 +0800
@@ -3675,9 +3675,6 @@ static struct inode *btrfs_new_inode(str
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 -urp 3/fs/btrfs/inode-item.c 4/fs/btrfs/inode-item.c
--- 3/fs/btrfs/inode-item.c 2009-08-24 10:36:35.733099000 +0800
+++ 4/fs/btrfs/inode-item.c 2009-08-24 10:39:12.206349392 +0800
@@ -177,8 +177,6 @@ int btrfs_insert_empty_inode(struct btrf
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 -urp 3/fs/btrfs/inode-map.c 4/fs/btrfs/inode-map.c
--- 3/fs/btrfs/inode-map.c 2009-08-24 10:36:35.734100000 +0800
+++ 4/fs/btrfs/inode-map.c 2009-08-25 13:12:02.360309951 +0800
@@ -43,9 +43,10 @@ int btrfs_find_highest_inode(struct btrf
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 +54,28 @@ 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;
}
+
diff -urp 3/fs/btrfs/tree-log.c 4/fs/btrfs/tree-log.c
--- 3/fs/btrfs/tree-log.c 2009-08-24 10:38:34.290099887 +0800
+++ 4/fs/btrfs/tree-log.c 2009-08-24 10:39:12.209349324 +0800
@@ -2959,7 +2959,6 @@ int btrfs_recover_log_trees(struct btrfs
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,
@@ -3018,11 +3017,6 @@ again:
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;
--
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