[PATCH review 04/11] mnt: Add MNT_UMOUNT flag
Eric W. Biederman
ebiederm at xmission.com
Mon Jan 5 20:46:20 UTC 2015
In some instances it is necessary to know if the the unmounting
process has begun on a mount. Add MNT_UMOUNT to make that reliably
testable.
This fix gets used in fixing locked mounts in MNT_DETACH
Cc: stable at vger.kernel.org
Signed-off-by: "Eric W. Biederman" <ebiederm at xmission.com>
---
fs/namespace.c | 4 +++-
fs/pnode.c | 1 +
include/linux/mount.h | 1 +
3 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index 44478b6e3719..60d4160cd2f4 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1336,8 +1336,10 @@ static void umount_tree(struct mount *mnt, enum umount_tree_flags how)
struct mount *p;
/* Gather the mounts to umount */
- for (p = mnt; p; p = next_mnt(p, mnt))
+ for (p = mnt; p; p = next_mnt(p, mnt)) {
+ p->mnt.mnt_flags |= MNT_UMOUNT;
list_move(&p->mnt_list, &tmp_list);
+ }
/* Hide the mounts from lookup_mnt and mnt_mounts */
list_for_each_entry(p, &tmp_list, mnt_list) {
diff --git a/fs/pnode.c b/fs/pnode.c
index bf012af709dd..ac3aa0d43b90 100644
--- a/fs/pnode.c
+++ b/fs/pnode.c
@@ -384,6 +384,7 @@ static void __propagate_umount(struct mount *mnt)
if (child && list_empty(&child->mnt_mounts)) {
list_del_init(&child->mnt_child);
hlist_del_init_rcu(&child->mnt_hash);
+ child->mnt.mnt_flags |= MNT_UMOUNT;
list_move_tail(&child->mnt_list, &mnt->mnt_list);
}
}
diff --git a/include/linux/mount.h b/include/linux/mount.h
index c2c561dc0114..564beeec5d83 100644
--- a/include/linux/mount.h
+++ b/include/linux/mount.h
@@ -61,6 +61,7 @@ struct mnt_namespace;
#define MNT_DOOMED 0x1000000
#define MNT_SYNC_UMOUNT 0x2000000
#define MNT_MARKED 0x4000000
+#define MNT_UMOUNT 0x8000000
struct vfsmount {
struct dentry *mnt_root; /* root of the mounted tree */
--
2.2.1
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