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-rw-r--r--fs/namespace.c67
1 files changed, 33 insertions, 34 deletions
diff --git a/fs/namespace.c b/fs/namespace.c
index 0acabea58319..a01c7730e9af 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -16,7 +16,6 @@
#include <linux/namei.h>
#include <linux/security.h>
#include <linux/idr.h>
-#include <linux/acct.h> /* acct_auto_close_mnt */
#include <linux/init.h> /* init_rootfs */
#include <linux/fs_struct.h> /* get_fs_root et.al. */
#include <linux/fsnotify.h> /* fsnotify_vfsmount_delete */
@@ -779,6 +778,20 @@ static void attach_mnt(struct mount *mnt,
list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
}
+static void attach_shadowed(struct mount *mnt,
+ struct mount *parent,
+ struct mount *shadows)
+{
+ if (shadows) {
+ hlist_add_behind_rcu(&mnt->mnt_hash, &shadows->mnt_hash);
+ list_add(&mnt->mnt_child, &shadows->mnt_child);
+ } else {
+ hlist_add_head_rcu(&mnt->mnt_hash,
+ m_hash(&parent->mnt, mnt->mnt_mountpoint));
+ list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
+ }
+}
+
/*
* vfsmount lock must be held for write
*/
@@ -797,12 +810,7 @@ static void commit_tree(struct mount *mnt, struct mount *shadows)
list_splice(&head, n->list.prev);
- if (shadows)
- hlist_add_behind_rcu(&mnt->mnt_hash, &shadows->mnt_hash);
- else
- hlist_add_head_rcu(&mnt->mnt_hash,
- m_hash(&parent->mnt, mnt->mnt_mountpoint));
- list_add_tail(&mnt->mnt_child, &parent->mnt_mounts);
+ attach_shadowed(mnt, parent, shadows);
touch_mnt_namespace(n);
}
@@ -951,7 +959,6 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root,
static void mntput_no_expire(struct mount *mnt)
{
-put_again:
rcu_read_lock();
mnt_add_count(mnt, -1);
if (likely(mnt->mnt_ns)) { /* shouldn't be the last one */
@@ -964,14 +971,6 @@ put_again:
unlock_mount_hash();
return;
}
- if (unlikely(mnt->mnt_pinned)) {
- mnt_add_count(mnt, mnt->mnt_pinned + 1);
- mnt->mnt_pinned = 0;
- rcu_read_unlock();
- unlock_mount_hash();
- acct_auto_close_mnt(&mnt->mnt);
- goto put_again;
- }
if (unlikely(mnt->mnt.mnt_flags & MNT_DOOMED)) {
rcu_read_unlock();
unlock_mount_hash();
@@ -994,6 +993,8 @@ put_again:
* so mnt_get_writers() below is safe.
*/
WARN_ON(mnt_get_writers(mnt));
+ if (unlikely(mnt->mnt_pins.first))
+ mnt_pin_kill(mnt);
fsnotify_vfsmount_delete(&mnt->mnt);
dput(mnt->mnt.mnt_root);
deactivate_super(mnt->mnt.mnt_sb);
@@ -1021,25 +1022,15 @@ struct vfsmount *mntget(struct vfsmount *mnt)
}
EXPORT_SYMBOL(mntget);
-void mnt_pin(struct vfsmount *mnt)
-{
- lock_mount_hash();
- real_mount(mnt)->mnt_pinned++;
- unlock_mount_hash();
-}
-EXPORT_SYMBOL(mnt_pin);
-
-void mnt_unpin(struct vfsmount *m)
+struct vfsmount *mnt_clone_internal(struct path *path)
{
- struct mount *mnt = real_mount(m);
- lock_mount_hash();
- if (mnt->mnt_pinned) {
- mnt_add_count(mnt, 1);
- mnt->mnt_pinned--;
- }
- unlock_mount_hash();
+ struct mount *p;
+ p = clone_mnt(real_mount(path->mnt), path->dentry, CL_PRIVATE);
+ if (IS_ERR(p))
+ return ERR_CAST(p);
+ p->mnt.mnt_flags |= MNT_INTERNAL;
+ return &p->mnt;
}
-EXPORT_SYMBOL(mnt_unpin);
static inline void mangle(struct seq_file *m, const char *s)
{
@@ -1505,6 +1496,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
continue;
for (s = r; s; s = next_mnt(s, r)) {
+ struct mount *t = NULL;
if (!(flag & CL_COPY_UNBINDABLE) &&
IS_MNT_UNBINDABLE(s)) {
s = skip_mnt_tree(s);
@@ -1526,7 +1518,14 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry,
goto out;
lock_mount_hash();
list_add_tail(&q->mnt_list, &res->mnt_list);
- attach_mnt(q, parent, p->mnt_mp);
+ mnt_set_mountpoint(parent, p->mnt_mp, q);
+ if (!list_empty(&parent->mnt_mounts)) {
+ t = list_last_entry(&parent->mnt_mounts,
+ struct mount, mnt_child);
+ if (t->mnt_mp != p->mnt_mp)
+ t = NULL;
+ }
+ attach_shadowed(q, parent, t);
unlock_mount_hash();
}
}