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authorAl Viro <viro@zeniv.linux.org.uk>2013-03-16 14:35:16 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2013-04-09 14:12:52 -0400
commite3197d83d6f5b9bd0e57a05592437ffa459ee106 (patch)
treead0a4f5f256f55ed8115c30823c0c967cbedba13 /fs/namespace.c
parent84d17192d2afd52aeba88c71ae4959a015f56a38 (diff)
saner umount_tree()/release_mounts(), part 1
global list of release_mounts() fodder, protected by namespace_sem; eventually, all umount_tree() callers will use it as kill list. Helper picking the contents of that list, releasing namespace_sem and doing release_mounts() on what it got. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/namespace.c')
-rw-r--r--fs/namespace.c17
1 files changed, 13 insertions, 4 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index d7bb5a55cf36..0d91711a3160 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1119,6 +1119,8 @@ int may_umount(struct vfsmount *mnt)
EXPORT_SYMBOL(may_umount);
+static LIST_HEAD(unmounted); /* protected by namespace_sem */
+
void release_mounts(struct list_head *head)
{
struct mount *mnt;
@@ -1143,6 +1145,14 @@ void release_mounts(struct list_head *head)
}
}
+static void namespace_unlock(void)
+{
+ LIST_HEAD(head);
+ list_splice_init(&unmounted, &head);
+ up_write(&namespace_sem);
+ release_mounts(&head);
+}
+
/*
* vfsmount lock must be held for write
* namespace_sem must be held for write
@@ -1252,17 +1262,16 @@ static int do_umount(struct mount *mnt, int flags)
event++;
if (!(flags & MNT_DETACH))
- shrink_submounts(mnt, &umount_list);
+ shrink_submounts(mnt, &unmounted);
retval = -EBUSY;
if (flags & MNT_DETACH || !propagate_mount_busy(mnt, 2)) {
if (!list_empty(&mnt->mnt_list))
- umount_tree(mnt, 1, &umount_list);
+ umount_tree(mnt, 1, &unmounted);
retval = 0;
}
br_write_unlock(&vfsmount_lock);
- up_write(&namespace_sem);
- release_mounts(&umount_list);
+ namespace_unlock();
return retval;
}