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authorJonathan Corbet <corbet@lwn.net>2008-05-15 11:29:38 -0600
committerJonathan Corbet <corbet@lwn.net>2008-06-20 14:05:48 -0600
commitabedd296e97a5d943e76999de97253f1b62a4846 (patch)
tree01c24863beedaf1546845cc74f8cf65f856b7c2e /drivers/char/lp.c
parent12ead6b098b65dd21d3ed4fcccf20025dbe86cc2 (diff)
downloadlinux-abedd296e97a5d943e76999de97253f1b62a4846.tar.bz2
lp: cdev lock_kernel() pushdown
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'drivers/char/lp.c')
-rw-r--r--drivers/char/lp.c38
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)