lp: cdev lock_kernel() pushdown

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

1 files changed, 26 insertions, 12 deletions

diff --git a/drivers/char/lp.c b/drivers/char/lp.c
index 60ac642752be..71abb4c33aa2 100644
--- a/drivers/char/lp.c
+++ b/drivers/char/lp.c
@@ -126,6 +126,7 @@
 #include <linux/device.h>
 #include <linux/wait.h>
 #include <linux/jiffies.h>
+#include <linux/smp_lock.h>
 
 #include <linux/parport.h>
 #undef LP_STATS
@@ -489,14 +490,21 @@ static ssize_t lp_read(struct file * file, char __user * buf,
 static int lp_open(struct inode * inode, struct file * file)
 {
         unsigned int minor = iminor(inode);
+        int ret = 0;
 
-        if (minor >= LP_NO)
-                return -ENXIO;
-        if ((LP_F(minor) & LP_EXIST) == 0)
-                return -ENXIO;
-        if (test_and_set_bit(LP_BUSY_BIT_POS, &LP_F(minor)))
-                return -EBUSY;
-
+        lock_kernel();
+        if (minor >= LP_NO) {
+                ret = -ENXIO;
+                goto out;
+        }
+        if ((LP_F(minor) & LP_EXIST) == 0) {
+                ret = -ENXIO;
+                goto out;
+        }
+        if (test_and_set_bit(LP_BUSY_BIT_POS, &LP_F(minor))) {
+                ret = -EBUSY;
+                goto out;
+        }
         /* If ABORTOPEN is set and the printer is offline or out of paper,
            we may still want to open it to perform ioctl()s.  Therefore we
            have commandeered O_NONBLOCK, even though it is being used in
@@ -510,21 +518,25 @@ static int lp_open(struct inode * inode, struct file * file)
                 if (status & LP_POUTPA) {
                         printk(KERN_INFO "lp%d out of paper\n", minor);
                         LP_F(minor) &= ~LP_BUSY;
-                        return -ENOSPC;
+                        ret = -ENOSPC;
+                        goto out;
                 } else if (!(status & LP_PSELECD)) {
                         printk(KERN_INFO "lp%d off-line\n", minor);
                         LP_F(minor) &= ~LP_BUSY;
-                        return -EIO;
+                        ret = -EIO;
+                        goto out;
                 } else if (!(status & LP_PERRORP)) {
                         printk(KERN_ERR "lp%d printer error\n", minor);
                         LP_F(minor) &= ~LP_BUSY;
-                        return -EIO;
+                        ret = -EIO;
+                        goto out;
                 }
         }
         lp_table[minor].lp_buffer = kmalloc(LP_BUFFER_SIZE, GFP_KERNEL);
         if (!lp_table[minor].lp_buffer) {
                 LP_F(minor) &= ~LP_BUSY;
-                return -ENOMEM;
+                ret = -ENOMEM;
+                goto out;
         }
         /* Determine if the peripheral supports ECP mode */
         lp_claim_parport_or_block (&lp_table[minor]);
@@ -540,7 +552,9 @@ static int lp_open(struct inode * inode, struct file * file)
         parport_negotiate (lp_table[minor].dev->port, IEEE1284_MODE_COMPAT);
         lp_release_parport (&lp_table[minor]);
         lp_table[minor].current_mode = IEEE1284_MODE_COMPAT;
-        return 0;
+out:
+        unlock_kernel();
+        return ret;
 }
 
 static int lp_release(struct inode * inode, struct file * file)