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-rw-r--r--ipc/mqueue.c74
1 files changed, 19 insertions, 55 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index d7f309f74dec..a808f29d4c5a 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -325,9 +325,8 @@ err:
static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode;
- struct ipc_namespace *ns = data;
+ struct ipc_namespace *ns = sb->s_fs_info;
- sb->s_fs_info = ns;
sb->s_iflags |= SB_I_NOEXEC | SB_I_NODEV;
sb->s_blocksize = PAGE_SIZE;
sb->s_blocksize_bits = PAGE_SHIFT;
@@ -344,44 +343,18 @@ static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
return 0;
}
-static struct file_system_type mqueue_fs_type;
-/*
- * Return value is pinned only by reference in ->mq_mnt; it will
- * live until ipcns dies. Caller does not need to drop it.
- */
-static struct vfsmount *mq_internal_mount(void)
-{
- struct ipc_namespace *ns = current->nsproxy->ipc_ns;
- struct vfsmount *m = ns->mq_mnt;
- if (m)
- return m;
- m = kern_mount_data(&mqueue_fs_type, ns);
- spin_lock(&mq_lock);
- if (unlikely(ns->mq_mnt)) {
- spin_unlock(&mq_lock);
- if (!IS_ERR(m))
- kern_unmount(m);
- return ns->mq_mnt;
- }
- if (!IS_ERR(m))
- ns->mq_mnt = m;
- spin_unlock(&mq_lock);
- return m;
-}
-
static struct dentry *mqueue_mount(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *data)
{
- struct vfsmount *m;
- if (flags & SB_KERNMOUNT)
- return mount_nodev(fs_type, flags, data, mqueue_fill_super);
- m = mq_internal_mount();
- if (IS_ERR(m))
- return ERR_CAST(m);
- atomic_inc(&m->mnt_sb->s_active);
- down_write(&m->mnt_sb->s_umount);
- return dget(m->mnt_root);
+ struct ipc_namespace *ns;
+ if (flags & SB_KERNMOUNT) {
+ ns = data;
+ data = NULL;
+ } else {
+ ns = current->nsproxy->ipc_ns;
+ }
+ return mount_ns(fs_type, flags, data, ns, ns->user_ns, mqueue_fill_super);
}
static void init_once(void *foo)
@@ -771,16 +744,13 @@ static int prepare_open(struct dentry *dentry, int oflag, int ro,
static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
struct mq_attr *attr)
{
- struct vfsmount *mnt = mq_internal_mount();
- struct dentry *root;
+ struct vfsmount *mnt = current->nsproxy->ipc_ns->mq_mnt;
+ struct dentry *root = mnt->mnt_root;
struct filename *name;
struct path path;
int fd, error;
int ro;
- if (IS_ERR(mnt))
- return PTR_ERR(mnt);
-
audit_mq_open(oflag, mode, attr);
if (IS_ERR(name = getname(u_name)))
@@ -791,7 +761,6 @@ static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
goto out_putname;
ro = mnt_want_write(mnt); /* we'll drop it in any case */
- root = mnt->mnt_root;
inode_lock(d_inode(root));
path.dentry = lookup_one_len(name->name, root, strlen(name->name));
if (IS_ERR(path.dentry)) {
@@ -840,9 +809,6 @@ SYSCALL_DEFINE1(mq_unlink, const char __user *, u_name)
struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
struct vfsmount *mnt = ipc_ns->mq_mnt;
- if (!mnt)
- return -ENOENT;
-
name = getname(u_name);
if (IS_ERR(name))
return PTR_ERR(name);
@@ -1569,26 +1535,28 @@ int mq_init_ns(struct ipc_namespace *ns)
ns->mq_msgsize_max = DFLT_MSGSIZEMAX;
ns->mq_msg_default = DFLT_MSG;
ns->mq_msgsize_default = DFLT_MSGSIZE;
- ns->mq_mnt = NULL;
+ ns->mq_mnt = kern_mount_data(&mqueue_fs_type, ns);
+ if (IS_ERR(ns->mq_mnt)) {
+ int err = PTR_ERR(ns->mq_mnt);
+ ns->mq_mnt = NULL;
+ return err;
+ }
return 0;
}
void mq_clear_sbinfo(struct ipc_namespace *ns)
{
- if (ns->mq_mnt)
- ns->mq_mnt->mnt_sb->s_fs_info = NULL;
+ ns->mq_mnt->mnt_sb->s_fs_info = NULL;
}
void mq_put_mnt(struct ipc_namespace *ns)
{
- if (ns->mq_mnt)
- kern_unmount(ns->mq_mnt);
+ kern_unmount(ns->mq_mnt);
}
static int __init init_mqueue_fs(void)
{
- struct vfsmount *m;
int error;
mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
@@ -1610,10 +1578,6 @@ static int __init init_mqueue_fs(void)
if (error)
goto out_filesystem;
- m = kern_mount_data(&mqueue_fs_type, &init_ipc_ns);
- if (IS_ERR(m))
- goto out_filesystem;
- init_ipc_ns.mq_mnt = m;
return 0;
out_filesystem: