[PATCH] pktcdvd: improve BKL and compat_ioctl.c usage

From: Arnd Bergmann
Date: Wed Apr 28 2010 - 08:37:15 EST


The pktcdvd driver uses proper locking and does not need the
BKL in the ioctl and llseek functions of the character device,
so kill both. Moving the compat_ioctl handling from common code
into the driver itself fixes build problems when CONFIG_BLOCK is
disabled.

Acked-by: Randy Dunlap <randy.dunlap@xxxxxxxxxx>
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
On Wednesday 28 April 2010, Stephen Rothwell wrote:

> My fixes tree is here: ssh://master.kernel.org/~sfr/next-fixes.git it
> currently only contains your pktcdvd patch. My understanding was that
> this patch was a fix for a build problem with Linus' tree.

Ah, I had forgotten that this was still needed and Jens or Peter
obviously never picked it up.

Linus, could you merge this now to fix building with CONFIG_BLOCK
disabled? It's fallout of a patch c5ecc484c "pktcdvd: use BIO list
management functions", but I fixed it because the problem appeared
in compat_ioctl handling. It now came up because the patch conflicted
with the BKL pushdown, which the original patch does as a side-effect.

Arnd

diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index ddf1942..8a549db 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -48,6 +48,7 @@
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
+#include <linux/compat.h>
#include <linux/kthread.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
@@ -2984,7 +2985,7 @@ static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
mutex_unlock(&ctl_mutex);
}

-static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
+static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
void __user *argp = (void __user *)arg;
struct pkt_ctrl_command ctrl_cmd;
@@ -3021,10 +3022,20 @@ static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cm
return ret;
}

+#ifdef CONFIG_COMPAT
+static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
+}
+#endif

static const struct file_operations pkt_ctl_fops = {
- .ioctl = pkt_ctl_ioctl,
- .owner = THIS_MODULE,
+ .open = nonseekable_open,
+ .unlocked_ioctl = pkt_ctl_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = pkt_ctl_compat_ioctl,
+#endif
+ .owner = THIS_MODULE,
};

static struct miscdevice pkt_misc = {
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index c32a1b6..641640d 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -102,7 +102,6 @@
#include <linux/nbd.h>
#include <linux/random.h>
#include <linux/filter.h>
-#include <linux/pktcdvd.h>

#include <linux/hiddev.h>

@@ -1126,8 +1125,6 @@ COMPATIBLE_IOCTL(PPGETMODE)
COMPATIBLE_IOCTL(PPGETPHASE)
COMPATIBLE_IOCTL(PPGETFLAGS)
COMPATIBLE_IOCTL(PPSETFLAGS)
-/* pktcdvd */
-COMPATIBLE_IOCTL(PACKET_CTRL_CMD)
/* Big A */
/* sparc only */
/* Big Q for sound/OSS */
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/