Btrfs: Integrate metadata reservation with start_transaction
Besides simplify the code, this change makes sure all metadata
reservation for normal metadata operations are released after
committing transaction.
Changes since V1:
Add code that check if unlink and rmdir will free space.
Add ENOSPC handling for clone ioctl.
Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 21ad37c..2616491 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -165,53 +165,89 @@
TRANS_USERSPACE,
};
-static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
- int num_blocks, int type)
+static int may_wait_transaction(struct btrfs_root *root, int type)
{
- struct btrfs_trans_handle *h =
- kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
- int ret;
-
- mutex_lock(&root->fs_info->trans_mutex);
if (!root->fs_info->log_root_recovering &&
((type == TRANS_START && !root->fs_info->open_ioctl_trans) ||
type == TRANS_USERSPACE))
+ return 1;
+ return 0;
+}
+
+static struct btrfs_trans_handle *start_transaction(struct btrfs_root *root,
+ u64 num_items, int type)
+{
+ struct btrfs_trans_handle *h;
+ struct btrfs_transaction *cur_trans;
+ int retries = 0;
+ int ret;
+again:
+ h = kmem_cache_alloc(btrfs_trans_handle_cachep, GFP_NOFS);
+ if (!h)
+ return ERR_PTR(-ENOMEM);
+
+ mutex_lock(&root->fs_info->trans_mutex);
+ if (may_wait_transaction(root, type))
wait_current_trans(root);
+
ret = join_transaction(root);
BUG_ON(ret);
- h->transid = root->fs_info->running_transaction->transid;
- h->transaction = root->fs_info->running_transaction;
- h->blocks_reserved = num_blocks;
+ cur_trans = root->fs_info->running_transaction;
+ cur_trans->use_count++;
+ mutex_unlock(&root->fs_info->trans_mutex);
+
+ h->transid = cur_trans->transid;
+ h->transaction = cur_trans;
h->blocks_used = 0;
h->block_group = 0;
+ h->bytes_reserved = 0;
h->delayed_ref_updates = 0;
h->block_rsv = NULL;
- if (!current->journal_info && type != TRANS_USERSPACE)
- current->journal_info = h;
+ smp_mb();
+ if (cur_trans->blocked && may_wait_transaction(root, type)) {
+ btrfs_commit_transaction(h, root);
+ goto again;
+ }
- root->fs_info->running_transaction->use_count++;
+ if (num_items > 0) {
+ ret = btrfs_trans_reserve_metadata(h, root, num_items,
+ &retries);
+ if (ret == -EAGAIN) {
+ btrfs_commit_transaction(h, root);
+ goto again;
+ }
+ if (ret < 0) {
+ btrfs_end_transaction(h, root);
+ return ERR_PTR(ret);
+ }
+ }
+
+ mutex_lock(&root->fs_info->trans_mutex);
record_root_in_trans(h, root);
mutex_unlock(&root->fs_info->trans_mutex);
+
+ if (!current->journal_info && type != TRANS_USERSPACE)
+ current->journal_info = h;
return h;
}
struct btrfs_trans_handle *btrfs_start_transaction(struct btrfs_root *root,
- int num_blocks)
+ int num_items)
{
- return start_transaction(root, num_blocks, TRANS_START);
+ return start_transaction(root, num_items, TRANS_START);
}
struct btrfs_trans_handle *btrfs_join_transaction(struct btrfs_root *root,
int num_blocks)
{
- return start_transaction(root, num_blocks, TRANS_JOIN);
+ return start_transaction(root, 0, TRANS_JOIN);
}
struct btrfs_trans_handle *btrfs_start_ioctl_transaction(struct btrfs_root *r,
int num_blocks)
{
- return start_transaction(r, num_blocks, TRANS_USERSPACE);
+ return start_transaction(r, 0, TRANS_USERSPACE);
}
/* wait for a transaction commit to be fully complete */
@@ -312,6 +348,8 @@
count++;
}
+ btrfs_trans_release_metadata(trans, root);
+
mutex_lock(&info->trans_mutex);
cur_trans = info->running_transaction;
WARN_ON(cur_trans != trans->transaction);
@@ -757,47 +795,49 @@
struct btrfs_root *root = pending->root;
struct btrfs_root *parent_root;
struct inode *parent_inode;
+ struct dentry *dentry;
struct extent_buffer *tmp;
struct extent_buffer *old;
int ret;
- u64 objectid;
- int namelen;
u64 index = 0;
-
- parent_inode = pending->dentry->d_parent->d_inode;
- parent_root = BTRFS_I(parent_inode)->root;
+ u64 objectid;
new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
if (!new_root_item) {
- ret = -ENOMEM;
+ pending->error = -ENOMEM;
goto fail;
}
+
ret = btrfs_find_free_objectid(trans, tree_root, 0, &objectid);
- if (ret)
+ if (ret) {
+ pending->error = ret;
goto fail;
+ }
key.objectid = objectid;
- /* record when the snapshot was created in key.offset */
- key.offset = trans->transid;
- btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
+ key.offset = (u64)-1;
+ key.type = BTRFS_ROOT_ITEM_KEY;
- memcpy(&pending->root_key, &key, sizeof(key));
- pending->root_key.offset = (u64)-1;
+ trans->block_rsv = &pending->block_rsv;
+ dentry = pending->dentry;
+ parent_inode = dentry->d_parent->d_inode;
+ parent_root = BTRFS_I(parent_inode)->root;
record_root_in_trans(trans, parent_root);
+
/*
* insert the directory item
*/
- namelen = strlen(pending->name);
ret = btrfs_set_inode_index(parent_inode, &index);
BUG_ON(ret);
ret = btrfs_insert_dir_item(trans, parent_root,
- pending->name, namelen,
- parent_inode->i_ino,
- &pending->root_key, BTRFS_FT_DIR, index);
+ dentry->d_name.name, dentry->d_name.len,
+ parent_inode->i_ino, &key,
+ BTRFS_FT_DIR, index);
BUG_ON(ret);
- btrfs_i_size_write(parent_inode, parent_inode->i_size + namelen * 2);
+ btrfs_i_size_write(parent_inode, parent_inode->i_size +
+ dentry->d_name.len * 2);
ret = btrfs_update_inode(trans, parent_root, parent_inode);
BUG_ON(ret);
@@ -814,22 +854,29 @@
free_extent_buffer(old);
btrfs_set_root_node(new_root_item, tmp);
- ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
- new_root_item);
- BUG_ON(ret);
+ /* record when the snapshot was created in key.offset */
+ key.offset = trans->transid;
+ ret = btrfs_insert_root(trans, tree_root, &key, new_root_item);
btrfs_tree_unlock(tmp);
free_extent_buffer(tmp);
-
- ret = btrfs_add_root_ref(trans, parent_root->fs_info->tree_root,
- pending->root_key.objectid,
- parent_root->root_key.objectid,
- parent_inode->i_ino, index, pending->name,
- namelen);
BUG_ON(ret);
+ /*
+ * insert root back/forward references
+ */
+ ret = btrfs_add_root_ref(trans, tree_root, objectid,
+ parent_root->root_key.objectid,
+ parent_inode->i_ino, index,
+ dentry->d_name.name, dentry->d_name.len);
+ BUG_ON(ret);
+
+ key.offset = (u64)-1;
+ pending->snap = btrfs_read_fs_root_no_name(root->fs_info, &key);
+ BUG_ON(IS_ERR(pending->snap));
fail:
kfree(new_root_item);
- return ret;
+ btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);
+ return 0;
}
/*
@@ -898,6 +945,8 @@
ret = btrfs_run_delayed_refs(trans, root, 0);
BUG_ON(ret);
+ btrfs_trans_release_metadata(trans, root);
+
cur_trans = trans->transaction;
/*
* set the flushing flag so procs in this transaction have to