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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>
This commit is contained in:
Al Viro 2013-03-16 15:12:40 -04:00
parent 328e6d9014
commit 97216be09e
1 changed files with 30 additions and 23 deletions
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53
fs/namespace.c
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@ -1121,11 +1121,21 @@ EXPORT_SYMBOL(may_umount);
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 release_mounts(struct list_head *head)
}
}
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 @@ static int do_umount(struct mount *mnt, int flags)
return retval;
}
down_write(&namespace_sem);
namespace_lock();
br_write_lock(&vfsmount_lock);
event++;
@ -1412,7 +1419,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
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 @@ struct vfsmount *collect_mounts(struct path *path)
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 @@ static struct mountpoint *lock_mount(struct path *path)
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 @@ static int do_change_type(struct path *path, int flag)
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 @@ static int do_change_type(struct path *path, int flag)
br_write_unlock(&vfsmount_lock);
out_unlock:
up_write(&namespace_sem);
namespace_unlock();
return err;
}
@ -2016,11 +2023,11 @@ int finish_automount(struct vfsmount *m, struct path *path)
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 @@ int finish_automount(struct vfsmount *m, struct path *path)
*/
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 @@ void mark_mounts_for_expiry(struct list_head *mounts)
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 @@ static struct mnt_namespace *dup_mnt_ns(struct mnt_namespace *mnt_ns,
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 @@ void put_mnt_ns(struct mnt_namespace *ns)
{
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);