X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=fs%2Fdevpts%2Finode.c;h=add566303c684336cce3d8f9c4fa0f98678adafc;hb=3e5f206c00f73f535c914eedc8b91f424c5a14ab;hp=cfe8466f7fef51d6ecdf338f0d71b6cc00aa19ca;hpb=19d402c1e75077e2bcfe17f7fe5bcfc8deb74991;p=firefly-linux-kernel-4.4.55.git

diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index cfe8466f7fef..c35ffdc12bba 100644
--- 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;