[PATCH] viotape: Push down BKL ioctls

[PATCH] viotape: Push down BKL ioctls

[Alan Cox]

Signed-off-by: Alan Cox <alan@redhat.com>

diff --git a/drivers/char/viotape.c b/drivers/char/viotape.c
index 58aad63..b75f79f 100644
--- a/drivers/char/viotape.c
+++ b/drivers/char/viotape.c
@@ -46,8 +46,9 @@
 #include <linux/completion.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/smp_lock.h>
+#include <linux/uaccess.h>
 
-#include <asm/uaccess.h>
 #include <asm/ioctls.h>
 #include <asm/firmware.h>
 #include <asm/vio.h>
@@ -509,18 +510,24 @@ free_op:
 }
 
 /* ioctl */
-static int viotap_ioctl(struct inode *inode, struct file *file,
-		unsigned int cmd, unsigned long arg)
+static long viotap_ioctl(struct file *file, unsigned int cmd,
+							unsigned long arg)
 {
 	HvLpEvent_Rc hvrc;
 	int ret;
 	struct viot_devinfo_struct devi;
 	struct mtop mtc;
 	u32 myOp;
-	struct op_struct *op = get_op_struct();
+	struct op_struct *op;
 
-	if (op == NULL)
+	lock_kernel();
+
+	op= get_op_struct();
+
+	if (op == NULL) {
+		unlock_kernel();
 		return -ENOMEM;
+	}
 
 	get_dev_info(file->f_path.dentry->d_inode, &devi);
 
@@ -661,6 +668,7 @@ static int viotap_ioctl(struct inode *inode, struct file *file,
 					&viomtget[devi.devno],
 					sizeof(viomtget[0])))
 			ret = -EFAULT;
+		unlock_kernel();
 		return ret;
 	case MTIOCPOS:
 		printk(VIOTAPE_KERN_WARN "Got an (unsupported) MTIOCPOS\n");
@@ -674,6 +682,7 @@ static int viotap_ioctl(struct inode *inode, struct file *file,
 free_op:
 	free_op_struct(op);
 	up(&reqSem);
+	unlock_kernel();
 	return ret;
 }
 
@@ -783,12 +792,12 @@ free_op:
 }
 
 const struct file_operations viotap_fops = {
-	.owner =	THIS_MODULE,
-	.read =		viotap_read,
-	.write =	viotap_write,
-	.ioctl =	viotap_ioctl,
-	.open =		viotap_open,
-	.release =	viotap_release,
+	.owner =		THIS_MODULE,
+	.read =			viotap_read,
+	.write =		viotap_write,
+	.unlocked_ioctl =	viotap_ioctl,
+	.open =			viotap_open,
+	.release =		viotap_release,
 };
 
 /* Handle interrupt events for tape */
@@ -1000,8 +1009,7 @@ static int chg_state(int index, unsigned char new_state, struct file *file)
 	if (*cur_state == VIOT_WRITING) {
 		struct mtop write_eof = { MTWEOF, 1 };
 
-		rc = viotap_ioctl(NULL, file, MTIOCTOP,
-				  (unsigned long)&write_eof);
+		rc = viotap_ioctl(file, MTIOCTOP, (unsigned long)&write_eof);
 	}
 	*cur_state = new_state;
 	return rc;

Re: [PATCH] viotape: Push down BKL ioctls

[Stephen Rothwell]

Hi Alan,

On Thu, 22 May 2008 22:20:12 +0100 Alan Cox <alan@lxorguk.ukuu.org.uk> wrote:
>
> -static int viotap_ioctl(struct inode *inode, struct file *file,
> -		unsigned int cmd, unsigned long arg)
> +static long viotap_ioctl(struct file *file, unsigned int cmd,
> +							unsigned long arg)

The inode parameter is used in this function (so it won't build after
this patch) but in a weird way.   I will do an alternate patch.

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

[PATCH] [POWERPC] viotape: use unlocked_ioctl

[Stephen Rothwell]

This pushes the BKL down into the driver.  Based on a patch by Alan Cox.

We need to do it this way for now as the inode parameter of viotap_ioctl
is used internally as a flag.  We should do a further cleanup patch.

Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
 drivers/char/viotape.c |   24 ++++++++++++++++++------
 1 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/drivers/char/viotape.c b/drivers/char/viotape.c
index 58aad63..0dda915 100644
--- a/drivers/char/viotape.c
+++ b/drivers/char/viotape.c
@@ -46,6 +46,7 @@
 #include <linux/completion.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
+#include <linux/smp_lock.h>
 
 #include <asm/uaccess.h>
 #include <asm/ioctls.h>
@@ -677,6 +678,17 @@ free_op:
 	return ret;
 }
 
+static long viotap_unlocked_ioctl(struct file *file,
+		unsigned int cmd, unsigned long arg)
+{
+	long rc;
+
+	lock_kernel();
+	rc = viotap_ioctl(file->f_path.dentry->d_inode, file, cmd, arg);
+	unlock_kernel();
+	return rc;
+}
+
 static int viotap_open(struct inode *inode, struct file *file)
 {
 	HvLpEvent_Rc hvrc;
@@ -783,12 +795,12 @@ free_op:
 }
 
 const struct file_operations viotap_fops = {
-	.owner =	THIS_MODULE,
-	.read =		viotap_read,
-	.write =	viotap_write,
-	.ioctl =	viotap_ioctl,
-	.open =		viotap_open,
-	.release =	viotap_release,
+	.owner =		THIS_MODULE,
+	.read =			viotap_read,
+	.write =		viotap_write,
+	.unlocked_ioctl =	viotap_unlocked_ioctl,
+	.open =			viotap_open,
+	.release =		viotap_release,
 };
 
 /* Handle interrupt events for tape */
-- 
1.5.5.1


-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/