Merge branch 'next' of git://git.infradead.org/users/pcmoore/selinux into next

[firefly-linux-kernel-4.4.55.git] / fs / devpts / inode.c

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index cfe8466f7fef51d6ecdf338f0d71b6cc00aa19ca..c35ffdc12bbafd1874dcea43ec5094867daf3e0d 100644 (file)
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -142,6 +142,8 @@ static inline struct super_block *pts_sb_from_inode(struct inode *inode)
        if (inode->i_sb->s_magic == DEVPTS_SUPER_MAGIC)
                return inode->i_sb;
 #endif
+       if (!devpts_mnt)
+               return NULL;
        return devpts_mnt->mnt_sb;
 }
 
@@ -253,7 +255,7 @@ static int mknod_ptmx(struct super_block *sb)
        if (!uid_valid(root_uid) || !gid_valid(root_gid))
                return -EINVAL;
 
-       mutex_lock(&root->d_inode->i_mutex);
+       mutex_lock(&d_inode(root)->i_mutex);
 
        /* If we have already created ptmx node, return */
        if (fsi->ptmx_dentry) {
@@ -290,7 +292,7 @@ static int mknod_ptmx(struct super_block *sb)
        fsi->ptmx_dentry = dentry;
        rc = 0;
 out:
-       mutex_unlock(&root->d_inode->i_mutex);
+       mutex_unlock(&d_inode(root)->i_mutex);
        return rc;
 }
 
@@ -298,7 +300,7 @@ static void update_ptmx_mode(struct pts_fs_info *fsi)
 {
        struct inode *inode;
        if (fsi->ptmx_dentry) {
-               inode = fsi->ptmx_dentry->d_inode;
+               inode = d_inode(fsi->ptmx_dentry);
                inode->i_mode = S_IFCHR|fsi->mount_opts.ptmxmode;
        }
 }
@@ -525,10 +527,14 @@ static struct file_system_type devpts_fs_type = {
 int devpts_new_index(struct inode *ptmx_inode)
 {
        struct super_block *sb = pts_sb_from_inode(ptmx_inode);
-       struct pts_fs_info *fsi = DEVPTS_SB(sb);
+       struct pts_fs_info *fsi;
        int index;
        int ida_ret;
 
+       if (!sb)
+               return -ENODEV;
+
+       fsi = DEVPTS_SB(sb);
 retry:
        if (!ida_pre_get(&fsi->allocated_ptys, GFP_KERNEL))
                return -ENOMEM;
@@ -584,11 +590,18 @@ struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
        struct dentry *dentry;
        struct super_block *sb = pts_sb_from_inode(ptmx_inode);
        struct inode *inode;
-       struct dentry *root = sb->s_root;
-       struct pts_fs_info *fsi = DEVPTS_SB(sb);
-       struct pts_mount_opts *opts = &fsi->mount_opts;
+       struct dentry *root;
+       struct pts_fs_info *fsi;
+       struct pts_mount_opts *opts;
        char s[12];
 
+       if (!sb)
+               return ERR_PTR(-ENODEV);
+
+       root = sb->s_root;
+       fsi = DEVPTS_SB(sb);
+       opts = &fsi->mount_opts;
+
        inode = new_inode(sb);
        if (!inode)
                return ERR_PTR(-ENOMEM);
@@ -602,18 +615,18 @@ struct inode *devpts_pty_new(struct inode *ptmx_inode, dev_t device, int index,
 
        sprintf(s, "%d", index);
 
-       mutex_lock(&root->d_inode->i_mutex);
+       mutex_lock(&d_inode(root)->i_mutex);
 
        dentry = d_alloc_name(root, s);
        if (dentry) {
                d_add(dentry, inode);
-               fsnotify_create(root->d_inode, dentry);
+               fsnotify_create(d_inode(root), dentry);
        } else {
                iput(inode);
                inode = ERR_PTR(-ENOMEM);
        }
 
-       mutex_unlock(&root->d_inode->i_mutex);
+       mutex_unlock(&d_inode(root)->i_mutex);
 
        return inode;
 }
@@ -658,7 +671,7 @@ void devpts_pty_kill(struct inode *inode)
 
        BUG_ON(inode->i_rdev == MKDEV(TTYAUX_MAJOR, PTMX_MINOR));
 
-       mutex_lock(&root->d_inode->i_mutex);
+       mutex_lock(&d_inode(root)->i_mutex);
 
        dentry = d_find_alias(inode);
 
@@ -667,7 +680,7 @@ void devpts_pty_kill(struct inode *inode)
        dput(dentry);   /* d_alloc_name() in devpts_pty_new() */
        dput(dentry);           /* d_find_alias above */
 
-       mutex_unlock(&root->d_inode->i_mutex);
+       mutex_unlock(&d_inode(root)->i_mutex);
 }
 
 static int __init init_devpts_fs(void)
@@ -676,12 +689,16 @@ static int __init init_devpts_fs(void)
        struct ctl_table_header *table;
 
        if (!err) {
+               struct vfsmount *mnt;
+
                table = register_sysctl_table(pty_root_table);
-               devpts_mnt = kern_mount(&devpts_fs_type);
-               if (IS_ERR(devpts_mnt)) {
-                       err = PTR_ERR(devpts_mnt);
+               mnt = kern_mount(&devpts_fs_type);
+               if (IS_ERR(mnt)) {
+                       err = PTR_ERR(mnt);
                        unregister_filesystem(&devpts_fs_type);
                        unregister_sysctl_table(table);
+               } else {
+                       devpts_mnt = mnt;
                }
        }
        return err;