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| author | Miklos Szeredi <mszeredi@suse.cz> | 2012-08-10 17:40:13 +0200 |
|---|---|---|
| committer | John Rigby <john.rigby@linaro.org> | 2012-08-15 23:46:02 -0600 |
| commit | 459b85e362b0f3e607210a257787d2fc18055308 (patch) | |
| tree | 7f2e63c7b9f418f9dc3e72e3d3873ab9c5e944ed | |
| parent | 80e75f84686bc11d7e9de68c484b132b3c69c9b1 (diff) | |
vfs: introduce clone_private_mount()
Overlayfs needs a private clone of the mount, so create a function for
this and export to modules.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
| -rw-r--r-- | fs/namespace.c | 18 | ||||
| -rw-r--r-- | include/linux/mount.h | 3 |
2 files changed, 21 insertions, 0 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 4d31f73e256..b4712ea1d78 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1387,6 +1387,24 @@ void drop_collected_mounts(struct vfsmount *mnt) release_mounts(&umount_list); } +struct vfsmount *clone_private_mount(struct path *path) +{ + struct mount *old_mnt = real_mount(path->mnt); + struct mount *new_mnt; + + if (IS_MNT_UNBINDABLE(old_mnt)) + return ERR_PTR(-EINVAL); + + down_read(&namespace_sem); + new_mnt = clone_mnt(old_mnt, path->dentry, CL_PRIVATE); + up_read(&namespace_sem); + if (!new_mnt) + return ERR_PTR(-ENOMEM); + + return &new_mnt->mnt; +} +EXPORT_SYMBOL_GPL(clone_private_mount); + int iterate_mounts(int (*f)(struct vfsmount *, void *), void *arg, struct vfsmount *root) { diff --git a/include/linux/mount.h b/include/linux/mount.h index d7029f4a191..344a2623eb2 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -66,6 +66,9 @@ extern void mnt_pin(struct vfsmount *mnt); extern void mnt_unpin(struct vfsmount *mnt); extern int __mnt_is_readonly(struct vfsmount *mnt); +struct path; +extern struct vfsmount *clone_private_mount(struct path *path); + struct file_system_type; extern struct vfsmount *vfs_kern_mount(struct file_system_type *type, int flags, const char *name, |