v2: Always drop the lock when exiting early.
v3: Make detach_mounts robust about freeing several
mounts on the same mountpoint at one time, and remove
the unneeded mnt_list list test.
Signed-off-by: Eric W. Biederman <ebieder...@twitter.com>
---
fs/mount.h | 1 +
fs/namespace.c | 24 ++++++++++++++++++++++++
2 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/fs/mount.h b/fs/mount.h
index e4342b8dfab1..7a6a2bb3f290 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -79,6 +79,7 @@ static inline int is_mounted(struct vfsmount *mnt)
}
extern struct mount *__lookup_mnt(struct vfsmount *, struct dentry *, int);
+extern void detach_mounts(struct dentry *dentry);
static inline void get_mnt_ns(struct mnt_namespace *ns)
{
diff --git a/fs/namespace.c b/fs/namespace.c
index e4fe22c23e00..78f7c5c9e673 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1295,6 +1295,30 @@ static int do_umount(struct mount *mnt, int flags)
return retval;
}
+void detach_mounts(struct dentry *dentry)
+{
+ struct mountpoint *mp;
+ struct mount *mnt;
+
+ namespace_lock();
+ if (!d_mountpoint(dentry))
+ goto out_unlock;
+
+ mp = new_mountpoint(dentry);
+ if (IS_ERR(mp))
+ goto out_unlock;
+
+ br_write_lock(&vfsmount_lock);
+ while (!list_empty(&mp->m_list)) {
+ mnt = list_first_entry(&mp->m_list, struct mount, mnt_mp_list);
+ umount_tree(mnt, 1);
+ }
+ br_write_unlock(&vfsmount_lock);
+ put_mountpoint(mp);
+out_unlock:
+ namespace_unlock();
+}
+
/*
* Is the caller allowed to modify his namespace?
*/
--
1.7.5.4
--
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