diff options
| -rw-r--r-- | fs/pnode.c | 32 | ||||
| -rw-r--r-- | fs/pnode.h | 1 |
2 files changed, 30 insertions, 3 deletions
diff --git a/fs/pnode.c b/fs/pnode.c index 89890293dd0a..6367e1e435c6 100644 --- a/fs/pnode.c +++ b/fs/pnode.c @@ -382,6 +382,26 @@ void propagate_mount_unlock(struct mount *mnt) } /* + * Mark all mounts that the MNT_LOCKED logic will allow to be unmounted. + */ +static void mark_umount_candidates(struct mount *mnt) +{ + struct mount *parent = mnt->mnt_parent; + struct mount *m; + + BUG_ON(parent == mnt); + + for (m = propagation_next(parent, parent); m; + m = propagation_next(m, parent)) { + struct mount *child = __lookup_mnt_last(&m->mnt, + mnt->mnt_mountpoint); + if (child && (!IS_MNT_LOCKED(child) || IS_MNT_MARKED(m))) { + SET_MNT_MARK(child); + } + } +} + +/* * NOTE: unmounting 'mnt' naturally propagates to all other mounts its * parent propagates to. */ @@ -398,10 +418,13 @@ static void __propagate_umount(struct mount *mnt) struct mount *child = __lookup_mnt_last(&m->mnt, mnt->mnt_mountpoint); /* - * umount the child only if the child has no - * other children + * umount the child only if the child has no children + * and the child is marked safe to unmount. */ - if (child && list_empty(&child->mnt_mounts)) { + if (!child || !IS_MNT_MARKED(child)) + continue; + CLEAR_MNT_MARK(child); + if (list_empty(&child->mnt_mounts)) { list_del_init(&child->mnt_child); child->mnt.mnt_flags |= MNT_UMOUNT; list_move_tail(&child->mnt_list, &mnt->mnt_list); @@ -420,6 +443,9 @@ int propagate_umount(struct list_head *list) { struct mount *mnt; + list_for_each_entry_reverse(mnt, list, mnt_list) + mark_umount_candidates(mnt); + list_for_each_entry(mnt, list, mnt_list) __propagate_umount(mnt); return 0; diff --git a/fs/pnode.h b/fs/pnode.h index af47d4bd7b31..0fcdbe7ca648 100644 --- a/fs/pnode.h +++ b/fs/pnode.h @@ -19,6 +19,7 @@ #define IS_MNT_MARKED(m) ((m)->mnt.mnt_flags & MNT_MARKED) #define SET_MNT_MARK(m) ((m)->mnt.mnt_flags |= MNT_MARKED) #define CLEAR_MNT_MARK(m) ((m)->mnt.mnt_flags &= ~MNT_MARKED) +#define IS_MNT_LOCKED(m) ((m)->mnt.mnt_flags & MNT_LOCKED) #define CL_EXPIRE 0x01 #define CL_SLAVE 0x02 |