sg: cdev lock_kernel() pushdown

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

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index c9d7f721b9e2..4284625ed035 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -49,6 +49,7 @@ static int sg_version_num = 30534;	/* 2 digits for each component */
 #include <linux/delay.h>
 #include <linux/scatterlist.h>
 #include <linux/blktrace_api.h>
+#include <linux/smp_lock.h>
 
 #include "scsi.h"
 #include <scsi/scsi_dbg.h>
@@ -227,19 +228,26 @@ sg_open(struct inode *inode, struct file *filp)
         int res;
         int retval;
 
+        lock_kernel();
         nonseekable_open(inode, filp);
         SCSI_LOG_TIMEOUT(3, printk("sg_open: dev=%d, flags=0x%x\n", dev, flags));
         sdp = sg_get_dev(dev);
-        if ((!sdp) || (!sdp->device))
+        if ((!sdp) || (!sdp->device)) {
+                unlock_kernel();
                 return -ENXIO;
-        if (sdp->detached)
+        }
+        if (sdp->detached) {
+                unlock_kernel();
                 return -ENODEV;
+        }
 
         /* This driver's module count bumped by fops_get in <linux/fs.h> */
         /* Prevent the device driver from vanishing while we sleep */
         retval = scsi_device_get(sdp->device);
-        if (retval)
+        if (retval) {
+                unlock_kernel();
                 return retval;
+        }
 
         if (!((flags & O_NONBLOCK) ||
               scsi_block_when_processing_errors(sdp->device))) {
@@ -295,10 +303,12 @@ sg_open(struct inode *inode, struct file *filp)
                 retval = -ENOMEM;
                 goto error_out;
         }
+        unlock_kernel();
         return 0;
 
       error_out:
         scsi_device_put(sdp->device);
+        unlock_kernel();
         return retval;
 }