fold release_mounts() into namespace_unlock()
... and provide namespace_lock() as a trivial wrapper;
switch to those two consistently.
Result is patterned after rtnl_lock/rtnl_unlock pair.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/namespace.c b/fs/namespace.c
index fa93d54..ed0708f 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1121,11 +1121,21 @@
static LIST_HEAD(unmounted); /* protected by namespace_sem */
-static void release_mounts(struct list_head *head)
+static void namespace_unlock(void)
{
struct mount *mnt;
- while (!list_empty(head)) {
- mnt = list_first_entry(head, struct mount, mnt_hash);
+ LIST_HEAD(head);
+
+ if (likely(list_empty(&unmounted))) {
+ up_write(&namespace_sem);
+ return;
+ }
+
+ list_splice_init(&unmounted, &head);
+ up_write(&namespace_sem);
+
+ while (!list_empty(&head)) {
+ mnt = list_first_entry(&head, struct mount, mnt_hash);
list_del_init(&mnt->mnt_hash);
if (mnt_has_parent(mnt)) {
struct dentry *dentry;
@@ -1145,12 +1155,9 @@
}
}
-static void namespace_unlock(void)
+static inline void namespace_lock(void)
{
- LIST_HEAD(head);
- list_splice_init(&unmounted, &head);
- up_write(&namespace_sem);
- release_mounts(&head);
+ down_write(&namespace_sem);
}
/*
@@ -1256,7 +1263,7 @@
return retval;
}
- down_write(&namespace_sem);
+ namespace_lock();
br_write_lock(&vfsmount_lock);
event++;
@@ -1412,7 +1419,7 @@
struct vfsmount *collect_mounts(struct path *path)
{
struct mount *tree;
- down_write(&namespace_sem);
+ namespace_lock();
tree = copy_tree(real_mount(path->mnt), path->dentry,
CL_COPY_ALL | CL_PRIVATE);
namespace_unlock();
@@ -1423,7 +1430,7 @@
void drop_collected_mounts(struct vfsmount *mnt)
{
- down_write(&namespace_sem);
+ namespace_lock();
br_write_lock(&vfsmount_lock);
umount_tree(real_mount(mnt), 0);
br_write_unlock(&vfsmount_lock);
@@ -1593,18 +1600,18 @@
mutex_unlock(&dentry->d_inode->i_mutex);
return ERR_PTR(-ENOENT);
}
- down_write(&namespace_sem);
+ namespace_lock();
mnt = lookup_mnt(path);
if (likely(!mnt)) {
struct mountpoint *mp = new_mountpoint(dentry);
if (IS_ERR(mp)) {
- up_write(&namespace_sem);
+ namespace_unlock();
mutex_unlock(&dentry->d_inode->i_mutex);
return mp;
}
return mp;
}
- up_write(&namespace_sem);
+ namespace_unlock();
mutex_unlock(&path->dentry->d_inode->i_mutex);
path_put(path);
path->mnt = mnt;
@@ -1667,7 +1674,7 @@
if (!type)
return -EINVAL;
- down_write(&namespace_sem);
+ namespace_lock();
if (type == MS_SHARED) {
err = invent_group_ids(mnt, recurse);
if (err)
@@ -1680,7 +1687,7 @@
br_write_unlock(&vfsmount_lock);
out_unlock:
- up_write(&namespace_sem);
+ namespace_unlock();
return err;
}
@@ -2016,11 +2023,11 @@
fail:
/* remove m from any expiration list it may be on */
if (!list_empty(&mnt->mnt_expire)) {
- down_write(&namespace_sem);
+ namespace_lock();
br_write_lock(&vfsmount_lock);
list_del_init(&mnt->mnt_expire);
br_write_unlock(&vfsmount_lock);
- up_write(&namespace_sem);
+ namespace_unlock();
}
mntput(m);
mntput(m);
@@ -2034,13 +2041,13 @@
*/
void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list)
{
- down_write(&namespace_sem);
+ namespace_lock();
br_write_lock(&vfsmount_lock);
list_add_tail(&real_mount(mnt)->mnt_expire, expiry_list);
br_write_unlock(&vfsmount_lock);
- up_write(&namespace_sem);
+ namespace_unlock();
}
EXPORT_SYMBOL(mnt_set_expiry);
@@ -2057,7 +2064,7 @@
if (list_empty(mounts))
return;
- down_write(&namespace_sem);
+ namespace_lock();
br_write_lock(&vfsmount_lock);
/* extract from the expiration list every vfsmount that matches the
@@ -2373,7 +2380,7 @@
if (IS_ERR(new_ns))
return new_ns;
- down_write(&namespace_sem);
+ namespace_lock();
/* First pass: copy the tree topology */
copy_flags = CL_COPY_ALL | CL_EXPIRE;
if (user_ns != mnt_ns->user_ns)
@@ -2733,7 +2740,7 @@
{
if (!atomic_dec_and_test(&ns->count))
return;
- down_write(&namespace_sem);
+ namespace_lock();
br_write_lock(&vfsmount_lock);
umount_tree(ns->root, 0);
br_write_unlock(&vfsmount_lock);