mtdchar: cdev lock_kernel() pushdown

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 16 insertions, 6 deletions

diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 5d3ac512ce16..129d429cd2da 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 
 #include <linux/mtd/mtd.h>
 #include <linux/mtd/compatmac.h>
@@ -86,6 +87,7 @@ static int mtd_open(struct inode *inode, struct file *file)
 {
         int minor = iminor(inode);
         int devnum = minor >> 1;
+        int ret = 0;
         struct mtd_info *mtd;
         struct mtd_file_info *mfi;
 
@@ -98,31 +100,39 @@ static int mtd_open(struct inode *inode, struct file *file)
         if ((file->f_mode & 2) && (minor & 1))
                 return -EACCES;
 
+        lock_kernel();
         mtd = get_mtd_device(NULL, devnum);
 
-        if (IS_ERR(mtd))
-                return PTR_ERR(mtd);
+        if (IS_ERR(mtd)) {
+                ret = PTR_ERR(mtd);
+                goto out;
+        }
 
         if (MTD_ABSENT == mtd->type) {
                 put_mtd_device(mtd);
-                return -ENODEV;
+                ret = -ENODEV;
+                goto out;
         }
 
         /* You can't open it RW if it's not a writeable device */
         if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
                 put_mtd_device(mtd);
-                return -EACCES;
+                ret = -EACCES;
+                goto out;
         }
 
         mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
         if (!mfi) {
                 put_mtd_device(mtd);
-                return -ENOMEM;
+                ret = -ENOMEM;
+                goto out;
         }
         mfi->mtd = mtd;
         file->private_data = mfi;
 
-        return 0;
+out:
+        unlock_kernel();
+        return ret;
 } /* mtd_open */
 
 /*====================================================================*/