|
 |
24d93b |
From 9cc2c0f41c403a05989bc3ca2af650247d452f65 Mon Sep 17 00:00:00 2001
|
|
|
24d93b |
From: "T.kabe" <kabe@>
|
|
|
24d93b |
Date: Mon, 6 Mar 2017 15:18:55 +0900
|
|
|
24d93b |
Subject: [PATCH 2/4] vfs: Keep a list of mounts on a mount point
|
|
|
24d93b |
|
|
|
24d93b |
[upstream commit 0a5eb7c8189922e86a840972cd0b57e41de6f031]
|
|
|
24d93b |
Author: Eric W. Biederman <ebiederman@twitter.com>
|
|
|
24d93b |
Date: Sun Sep 22 19:37:01 2013 -0700
|
|
|
24d93b |
|
|
|
24d93b |
vfs: Keep a list of mounts on a mount point
|
|
|
24d93b |
|
|
|
24d93b |
To spot any possible problems call BUG if a mountpoint
|
|
|
24d93b |
is put when it's list of mounts is not empty.
|
|
|
24d93b |
|
|
|
24d93b |
AV: use hlist instead of list_head
|
|
|
24d93b |
|
|
|
24d93b |
Reviewed-by: Miklos Szeredi <miklos@szeredi.hu>
|
|
|
24d93b |
Signed-off-by: Eric W. Biederman <ebiederman@twitter.com>
|
|
|
24d93b |
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
|
24d93b |
---
|
|
|
24d93b |
fs/mount.h | 2 ++
|
|
|
24d93b |
fs/namespace.c | 6 ++++++
|
|
|
24d93b |
2 files changed, 8 insertions(+)
|
|
|
24d93b |
|
|
|
24d93b |
diff --git a/fs/mount.h b/fs/mount.h
|
|
|
24d93b |
index b870800..92fecbe 100644
|
|
|
24d93b |
--- a/fs/mount.h
|
|
|
24d93b |
+++ b/fs/mount.h
|
|
|
24d93b |
@@ -21,6 +21,7 @@ struct mnt_pcp {
|
|
|
24d93b |
struct mountpoint {
|
|
|
24d93b |
struct list_head m_hash;
|
|
|
24d93b |
struct dentry *m_dentry;
|
|
|
24d93b |
+ struct hlist_head m_list;
|
|
|
24d93b |
int m_count;
|
|
|
24d93b |
};
|
|
|
24d93b |
|
|
|
24d93b |
@@ -47,6 +48,7 @@ struct mount {
|
|
|
24d93b |
struct mount *mnt_master; /* slave is on master->mnt_slave_list */
|
|
|
24d93b |
struct mnt_namespace *mnt_ns; /* containing namespace */
|
|
|
24d93b |
struct mountpoint *mnt_mp; /* where is it mounted */
|
|
|
24d93b |
+ struct hlist_node mnt_mp_list; /* list mounts with the same mountpoint */
|
|
|
24d93b |
#ifdef CONFIG_FSNOTIFY
|
|
|
24d93b |
struct hlist_head mnt_fsnotify_marks;
|
|
|
24d93b |
__u32 mnt_fsnotify_mask;
|
|
|
24d93b |
diff --git a/fs/namespace.c b/fs/namespace.c
|
|
|
24d93b |
index 0053bfc..c238481 100644
|
|
|
24d93b |
--- a/fs/namespace.c
|
|
|
24d93b |
+++ b/fs/namespace.c
|
|
|
24d93b |
@@ -197,6 +197,7 @@ static struct mount *alloc_vfsmnt(const char *name)
|
|
|
24d93b |
INIT_LIST_HEAD(&mnt->mnt_share);
|
|
|
24d93b |
INIT_LIST_HEAD(&mnt->mnt_slave_list);
|
|
|
24d93b |
INIT_LIST_HEAD(&mnt->mnt_slave);
|
|
|
24d93b |
+ INIT_HLIST_NODE(&mnt->mnt_mp_list);
|
|
|
24d93b |
#ifdef CONFIG_FSNOTIFY
|
|
|
24d93b |
INIT_HLIST_HEAD(&mnt->mnt_fsnotify_marks);
|
|
|
24d93b |
#endif
|
|
|
24d93b |
@@ -636,6 +637,7 @@ static struct mountpoint *new_mountpoint(struct dentry *dentry)
|
|
|
24d93b |
mp->m_dentry = dentry;
|
|
|
24d93b |
mp->m_count = 1;
|
|
|
24d93b |
list_add(&mp->m_hash, chain);
|
|
|
24d93b |
+ INIT_HLIST_HEAD(&mp->m_list);
|
|
|
24d93b |
return mp;
|
|
|
24d93b |
}
|
|
|
24d93b |
|
|
|
24d93b |
@@ -643,6 +645,7 @@ static void put_mountpoint(struct mountpoint *mp)
|
|
|
24d93b |
{
|
|
|
24d93b |
if (!--mp->m_count) {
|
|
|
24d93b |
struct dentry *dentry = mp->m_dentry;
|
|
|
24d93b |
+ BUG_ON(!hlist_empty(&mp->m_list));
|
|
|
24d93b |
spin_lock(&dentry->d_lock);
|
|
|
24d93b |
dentry->d_flags &= ~DCACHE_MOUNTED;
|
|
|
24d93b |
spin_unlock(&dentry->d_lock);
|
|
|
24d93b |
@@ -689,6 +692,7 @@ static void detach_mnt(struct mount *mnt, struct path *old_path)
|
|
|
24d93b |
mnt->mnt_mountpoint = mnt->mnt.mnt_root;
|
|
|
24d93b |
list_del_init(&mnt->mnt_child);
|
|
|
24d93b |
list_del_init(&mnt->mnt_hash);
|
|
|
24d93b |
+ hlist_del_init(&mnt->mnt_mp_list);
|
|
|
24d93b |
put_mountpoint(mnt->mnt_mp);
|
|
|
24d93b |
mnt->mnt_mp = NULL;
|
|
|
24d93b |
}
|
|
|
24d93b |
@@ -705,6 +709,7 @@ void mnt_set_mountpoint(struct mount *mnt,
|
|
|
24d93b |
child_mnt->mnt_mountpoint = dget(mp->m_dentry);
|
|
|
24d93b |
child_mnt->mnt_parent = mnt;
|
|
|
24d93b |
child_mnt->mnt_mp = mp;
|
|
|
24d93b |
+ hlist_add_head(&child_mnt->mnt_mp_list, &mp->m_list);
|
|
|
24d93b |
}
|
|
|
24d93b |
|
|
|
24d93b |
/*
|
|
|
24d93b |
@@ -1207,6 +1212,7 @@ void umount_tree(struct mount *mnt, int propagate)
|
|
|
24d93b |
__touch_mnt_namespace(p->mnt_ns);
|
|
|
24d93b |
p->mnt_ns = NULL;
|
|
|
24d93b |
if (mnt_has_parent(p)) {
|
|
|
24d93b |
+ hlist_del_init(&p->mnt_mp_list);
|
|
|
24d93b |
p->mnt_parent->mnt_ghosts++;
|
|
|
24d93b |
put_mountpoint(p->mnt_mp);
|
|
|
24d93b |
p->mnt_mp = NULL;
|
|
|
24d93b |
--
|
|
|
24d93b |
1.8.3.1
|
|
|
24d93b |
|