summaryrefslogtreecommitdiff
path: root/fs/namespace.c
diff options
context:
space:
mode:
authorEric W. Biederman <ebiederm@xmission.com>2014-12-24 16:20:01 +0300
committerEric W. Biederman <ebiederm@xmission.com>2015-04-03 04:34:17 +0300
commite819f152104c9f7c9fe50e1aecce6f5d4bf06d65 (patch)
treee2f08411e078cce21fe838aea1ed7d9ca3be7812 /fs/namespace.c
parenta3b3c5627c8301ac850962b04f645dfab81e6a60 (diff)
downloadlinux-e819f152104c9f7c9fe50e1aecce6f5d4bf06d65.tar.xz
mnt: Improve the umount_tree flags
- Remove the unneeded declaration from pnode.h - Mark umount_tree static as it has no callers outside of namespace.c - Define an enumeration of umount_tree's flags. - Pass umount_tree's flags in by name This removes the magic numbers 0, 1 and 2 making the code a little clearer and makes it possible for there to be lazy unmounts that don't propagate. Which is what __detach_mounts actually wants for example. Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Diffstat (limited to 'fs/namespace.c')
-rw-r--r--fs/namespace.c31
1 files changed, 16 insertions, 15 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index e1ee57206eef..e06e36777b90 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1317,14 +1317,15 @@ static inline void namespace_lock(void)
down_write(&namespace_sem);
}
+enum umount_tree_flags {
+ UMOUNT_SYNC = 1,
+ UMOUNT_PROPAGATE = 2,
+};
/*
* mount_lock must be held
* namespace_sem must be held for write
- * how = 0 => just this tree, don't propagate
- * how = 1 => propagate; we know that nobody else has reference to any victims
- * how = 2 => lazy umount
*/
-void umount_tree(struct mount *mnt, int how)
+static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
{
HLIST_HEAD(tmp_list);
struct mount *p;
@@ -1337,7 +1338,7 @@ void umount_tree(struct mount *mnt, int how)
hlist_for_each_entry(p, &tmp_list, mnt_hash)
list_del_init(&p->mnt_child);
- if (how)
+ if (how & UMOUNT_PROPAGATE)
propagate_umount(&tmp_list);
while (!hlist_empty(&tmp_list)) {
@@ -1347,7 +1348,7 @@ void umount_tree(struct mount *mnt, int how)
list_del_init(&p->mnt_list);
__touch_mnt_namespace(p->mnt_ns);
p->mnt_ns = NULL;
- if (how < 2)
+ if (how & UMOUNT_SYNC)
p->mnt.mnt_flags |= MNT_SYNC_UMOUNT;
pin_insert_group(&p->mnt_umount, &p->mnt_parent->mnt, &unmounted);
@@ -1445,14 +1446,14 @@ static int do_umount(struct mount *mnt, int flags)
if (flags & MNT_DETACH) {
if (!list_empty(&mnt->mnt_list))
- umount_tree(mnt, 2);
+ umount_tree(mnt, UMOUNT_PROPAGATE);
retval = 0;
} else {
shrink_submounts(mnt);
retval = -EBUSY;
if (!propagate_mount_busy(mnt, 2)) {
if (!list_empty(&mnt->mnt_list))
- umount_tree(mnt, 1);
+ umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);
retval = 0;
}
}
@@ -1484,7 +1485,7 @@ void __detach_mounts(struct dentry *dentry)
lock_mount_hash();
while (!hlist_empty(&mp->m_list)) {
mnt = hlist_entry(mp->m_list.first, struct mount, mnt_mp_list);
- umount_tree(mnt, 2);
+ umount_tree(mnt, UMOUNT_PROPAGATE);
}
unlock_mount_hash();
put_mountpoint(mp);
@@ -1646,7 +1647,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
out:
if (res) {
lock_mount_hash();
- umount_tree(res, 0);
+ umount_tree(res, UMOUNT_SYNC);
unlock_mount_hash();
}
return q;
@@ -1670,7 +1671,7 @@ void drop_collected_mounts(struct vfsmount *mnt)
{
namespace_lock();
lock_mount_hash();
- umount_tree(real_mount(mnt), 0);
+ umount_tree(real_mount(mnt), UMOUNT_SYNC);
unlock_mount_hash();
namespace_unlock();
}
@@ -1853,7 +1854,7 @@ static int attach_recursive_mnt(struct mount *source_mnt,
out_cleanup_ids:
while (!hlist_empty(&tree_list)) {
child = hlist_entry(tree_list.first, struct mount, mnt_hash);
- umount_tree(child, 0);
+ umount_tree(child, UMOUNT_SYNC);
}
unlock_mount_hash();
cleanup_group_ids(source_mnt, NULL);
@@ -2033,7 +2034,7 @@ static int do_loopback(struct path *path, const char *old_name,
err = graft_tree(mnt, parent, mp);
if (err) {
lock_mount_hash();
- umount_tree(mnt, 0);
+ umount_tree(mnt, UMOUNT_SYNC);
unlock_mount_hash();
}
out2:
@@ -2404,7 +2405,7 @@ void mark_mounts_for_expiry(struct list_head *mounts)
while (!list_empty(&graveyard)) {
mnt = list_first_entry(&graveyard, struct mount, mnt_expire);
touch_mnt_namespace(mnt->mnt_ns);
- umount_tree(mnt, 1);
+ umount_tree(mnt, UMOUNT_PROPAGATE|UMOUNT_SYNC);
}
unlock_mount_hash();
namespace_unlock();
@@ -2475,7 +2476,7 @@ static void shrink_submounts(struct mount *mnt)
m = list_first_entry(&graveyard, struct mount,
mnt_expire);
touch_mnt_namespace(m->mnt_ns);
- umount_tree(m, 1);
+ umount_tree(m, UMOUNT_PROPAGATE|UMOUNT_SYNC);
}
}
}