do_mq_open(): move all work prior to dentry_open() into a helper

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 31 insertions, 46 deletions

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index a2483524b633..e8a872e9c808 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -713,34 +713,44 @@ static void remove_notification(struct mqueue_inode_info *info)
         info->notify_user_ns = NULL;
 }
 
-/*
- * Invoked when creating a new queue via sys_mq_open
- */
-static int do_create(struct ipc_namespace *ipc_ns, struct inode *dir,
-                        struct path *path, int oflag, umode_t mode,
+static int prepare_open(struct dentry *dentry, int oflag, int ro,
+                        umode_t mode, struct filename *name,
                         struct mq_attr *attr)
 {
-        return vfs_mkobj(path->dentry, mode & ~current_umask(),
-                        mqueue_create_attr, attr);
-}
-
-/* Opens existing queue */
-static int do_open(struct path *path, int oflag)
-{
         static const int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE,
                                                   MAY_READ | MAY_WRITE };
         int acc;
+
+        if (oflag & O_CREAT) {
+                if (d_really_is_positive(dentry)) {     /* entry already exists */
+                        audit_inode(name, dentry, 0);
+                        if (oflag & O_EXCL)
+                                return -EEXIST;
+                } else {
+                        if (ro)
+                                return ro;
+
+                        audit_inode_parent_hidden(name, dentry->d_parent);
+                        return vfs_mkobj(dentry, mode & ~current_umask(),
+                                  mqueue_create_attr, attr);
+                }
+        } else {
+                if (d_really_is_negative(dentry)) {
+                        return -ENOENT;
+                } else {
+                        audit_inode(name, dentry, 0);
+                }
+        }
         if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
                 return -EINVAL;
         acc = oflag2acc[oflag & O_ACCMODE];
-        return inode_permission(d_inode(path->dentry), acc);
+        return inode_permission(d_inode(dentry), acc);
 }
 
 static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
                       struct mq_attr *attr)
 {
         struct path path;
-        struct file *filp;
         struct filename *name;
         int fd, error;
         struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
@@ -767,39 +777,14 @@ static int do_mq_open(const char __user *u_name, int oflag, umode_t mode,
         }
         path.mnt = mntget(mnt);
 
-        if (oflag & O_CREAT) {
-                if (d_really_is_positive(path.dentry)) {        /* entry already exists */
-                        audit_inode(name, path.dentry, 0);
-                        if (oflag & O_EXCL)
-                                error = -EEXIST;
-                        else
-                                error = do_open(&path, oflag);
-                } else {
-                        if (ro) {
-                                error = ro;
-                        } else {
-                                audit_inode_parent_hidden(name, root);
-                                error = do_create(ipc_ns, d_inode(root), &path,
-                                                 oflag, mode, attr);
-                        }
-                }
-        } else {
-                if (d_really_is_negative(path.dentry)) {
-                        error = -ENOENT;
-                } else {
-                        audit_inode(name, path.dentry, 0);
-                        error = do_open(&path, oflag);
-                }
+        error = prepare_open(path.dentry, oflag, ro, mode, name, attr);
+        if (!error) {
+                struct file *file = dentry_open(&path, oflag, current_cred());
+                if (!IS_ERR(file))
+                        fd_install(fd, file);
+                else
+                        error = PTR_ERR(file);
         }
-        if (error)
-                goto out;
-        filp = dentry_open(&path, oflag, current_cred());
-
-        if (!IS_ERR(filp))
-                fd_install(fd, filp);
-        else
-                error = PTR_ERR(filp);
-out:
         path_put(&path);
 out_putfd:
         if (error) {