Miao Xie
2013-Feb-28 10:04 UTC
[PATCH 2/3] Btrfs: fix wrong reserved space in qgroup during snap/subv creation
There are two problems in the space reservation of the snapshot/
subvolume creation.
- don''t reserve the space for the root item insertion
- the space which is reserved in the qgroup is different with
the free space reservation. we need reserve free space for
7 items, but in qgroup reservation, we need reserve space only
for 3 items.
So we implement new metadata reservation functions for the
snapshot/subvolume creation.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
fs/btrfs/ctree.h | 9 +++++-
fs/btrfs/extent-tree.c | 65 +++++++++++++++++++++++++++++++++++++++---------
fs/btrfs/ioctl.c | 62 +++++++++++++++++++++++++++++++--------------
fs/btrfs/transaction.c | 4 +--
fs/btrfs/transaction.h | 1 +
5 files changed, 105 insertions(+), 36 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index b355bb4..b98c451 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3068,8 +3068,13 @@ void btrfs_trans_release_metadata(struct
btrfs_trans_handle *trans,
int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans,
struct inode *inode);
void btrfs_orphan_release_metadata(struct inode *inode);
-int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
- struct btrfs_pending_snapshot *pending);
+int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv,
+ int nitems,
+ u64 *qgroup_reserved);
+void btrfs_subvolume_release_metadata(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv,
+ u64 qgroup_reserved);
int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes);
void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes);
int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes);
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 88831fa..b795ed9 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -4496,19 +4496,60 @@ void btrfs_orphan_release_metadata(struct inode *inode)
btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes);
}
-int btrfs_snap_reserve_metadata(struct btrfs_trans_handle *trans,
- struct btrfs_pending_snapshot *pending)
+/*
+ * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation
+ * root: the root of the parent directory
+ * rsv: block reservation
+ * items: the number of items that we need do reservation
+ * qgroup_reserved: used to return the reserved size in qgroup
+ *
+ * This function is used to reserve the space for snapshot/subvolume
+ * creation and deletion. Those operations are different with the
+ * common file/directory operations, they change two fs/file trees
+ * and root tree, the number of items that the qgroup reserves is
+ * different with the free space reservation. So we can not use
+ * the space reseravtion mechanism in start_transaction().
+ */
+int btrfs_subvolume_reserve_metadata(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv,
+ int items,
+ u64 *qgroup_reserved)
{
- struct btrfs_root *root = pending->root;
- struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root);
- struct btrfs_block_rsv *dst_rsv = &pending->block_rsv;
- /*
- * two for root back/forward refs, two for directory entries,
- * one for root of the snapshot and one for parent inode.
- */
- u64 num_bytes = btrfs_calc_trans_metadata_size(root, 6);
- dst_rsv->space_info = src_rsv->space_info;
- return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes);
+ u64 num_bytes;
+ int ret;
+
+ if (root->fs_info->quota_enabled) {
+ /* One for parent inode, two for dir entries */
+ num_bytes = 3 * root->leafsize;
+ ret = btrfs_qgroup_reserve(root, num_bytes);
+ if (ret)
+ return ret;
+ } else {
+ num_bytes = 0;
+ }
+
+ *qgroup_reserved = num_bytes;
+
+ num_bytes = btrfs_calc_trans_metadata_size(root, items);
+ rsv->space_info = __find_space_info(root->fs_info,
+ BTRFS_BLOCK_GROUP_METADATA);
+ ret = btrfs_block_rsv_add(root, rsv, num_bytes,
+ BTRFS_RESERVE_FLUSH_ALL);
+ if (ret) {
+ if (*qgroup_reserved)
+ btrfs_qgroup_free(root, *qgroup_reserved);
+ }
+
+ return ret;
+}
+
+void btrfs_subvolume_release_metadata(struct btrfs_root *root,
+ struct btrfs_block_rsv *rsv,
+ u64 qgroup_reserved)
+{
+ btrfs_block_rsv_release(root, rsv, (u64)-1);
+ if (qgroup_reserved)
+ btrfs_qgroup_free(root, qgroup_reserved);
}
/**
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 75c551d..8046cfc 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -363,7 +363,7 @@ static noinline int btrfs_ioctl_fitrim(struct file *file,
void __user *arg)
return 0;
}
-static noinline int create_subvol(struct btrfs_root *root,
+static noinline int create_subvol(struct inode *dir,
struct dentry *dentry,
char *name, int namelen,
u64 *async_transid,
@@ -374,32 +374,39 @@ static noinline int create_subvol(struct btrfs_root *root,
struct btrfs_root_item root_item;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
+ struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *new_root;
- struct dentry *parent = dentry->d_parent;
- struct inode *dir;
+ struct btrfs_block_rsv block_rsv;
struct timespec cur_time = CURRENT_TIME;
int ret;
int err;
u64 objectid;
u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
u64 index = 0;
+ u64 qgroup_reserved;
uuid_le new_uuid;
ret = btrfs_find_free_objectid(root->fs_info->tree_root, &objectid);
if (ret)
return ret;
- dir = parent->d_inode;
-
+ btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
- * 1 - inode item
- * 2 - refs
- * 1 - root item
- * 2 - dir items
+ * The same as the snapshot creation, please see the comment
+ * of create_snapshot().
*/
- trans = btrfs_start_transaction(root, 6);
- if (IS_ERR(trans))
- return PTR_ERR(trans);
+ ret = btrfs_subvolume_reserve_metadata(root, &block_rsv,
+ 7, &qgroup_reserved);
+ if (ret)
+ return ret;
+
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out;
+ }
+ trans->block_rsv = &block_rsv;
+ trans->bytes_reserved = block_rsv.size;
ret = btrfs_qgroup_inherit(trans, root->fs_info, 0, objectid, inherit);
if (ret)
@@ -515,6 +522,8 @@ static noinline int create_subvol(struct btrfs_root *root,
BUG_ON(ret);
fail:
+ trans->block_rsv = NULL;
+ trans->bytes_reserved = 0;
if (async_transid) {
*async_transid = trans->transid;
err = btrfs_commit_transaction_async(trans, root, 1);
@@ -526,7 +535,8 @@ fail:
if (!ret)
d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
-
+out:
+ btrfs_subvolume_release_metadata(root, &block_rsv, qgroup_reserved);
return ret;
}
@@ -549,21 +559,31 @@ static int create_snapshot(struct btrfs_root *root, struct
inode *dir,
btrfs_init_block_rsv(&pending_snapshot->block_rsv,
BTRFS_BLOCK_RSV_TEMP);
+ /*
+ * 1 - parent dir inode
+ * 2 - dir entries
+ * 1 - root item
+ * 2 - root ref/backref
+ * 1 - root of snapshot
+ */
+ ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
+ &pending_snapshot->block_rsv, 7,
+ &pending_snapshot->qgroup_reserved);
+ if (ret)
+ goto out;
+
pending_snapshot->dentry = dentry;
pending_snapshot->root = root;
pending_snapshot->readonly = readonly;
pending_snapshot->dir = dir;
pending_snapshot->inherit = inherit;
- trans = btrfs_start_transaction(root->fs_info->extent_root, 6);
+ trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto fail;
}
- ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
- BUG_ON(ret);
-
spin_lock(&root->fs_info->trans_lock);
list_add(&pending_snapshot->list,
&trans->transaction->pending_snapshots);
@@ -600,6 +620,10 @@ static int create_snapshot(struct btrfs_root *root, struct
inode *dir,
d_instantiate(dentry, inode);
ret = 0;
fail:
+ btrfs_subvolume_release_metadata(BTRFS_I(dir)->root,
+ &pending_snapshot->block_rsv,
+ pending_snapshot->qgroup_reserved);
+out:
kfree(pending_snapshot);
return ret;
}
@@ -733,8 +757,8 @@ static noinline int btrfs_mksubvol(struct path *parent,
error = create_snapshot(snap_src, dir, dentry, name, namelen,
async_transid, readonly, inherit);
} else {
- error = create_subvol(BTRFS_I(dir)->root, dentry,
- name, namelen, async_transid, inherit);
+ error = create_subvol(dir, dentry, name, namelen,
+ async_transid, inherit);
}
if (!error)
fsnotify_mkdir(dir, dentry);
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index 63390a3..61e34d8 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -1075,7 +1075,7 @@ static noinline int create_pending_snapshot(struct
btrfs_trans_handle *trans,
path = btrfs_alloc_path();
if (!path) {
ret = pending->error = -ENOMEM;
- goto path_alloc_fail;
+ return ret;
}
new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
@@ -1270,8 +1270,6 @@ no_free_objectid:
kfree(new_root_item);
root_item_alloc_fail:
btrfs_free_path(path);
-path_alloc_fail:
- btrfs_block_rsv_release(root, &pending->block_rsv, (u64)-1);
return ret;
}
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index 5f67fba..3c8e0d2 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -90,6 +90,7 @@ struct btrfs_pending_snapshot {
struct btrfs_qgroup_inherit *inherit;
/* block reservation for the operation */
struct btrfs_block_rsv block_rsv;
+ u64 qgroup_reserved;
/* extra metadata reseration for relocation */
int error;
bool readonly;
--
1.6.5.2
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