[PATCH] kill empty chardev open/release methods

From: Christoph Hellwig
Date: Fri May 16 2008 - 12:03:45 EST


On Fri, May 16, 2008 at 11:49:22AM -0400, Christoph Hellwig wrote:
> On Fri, May 16, 2008 at 09:44:06AM -0600, Jonathan Corbet wrote:
> > trivial as to not require locking (quite few of them are "return 0;"), or
>
> If they literaly are 'return 0' you can just remove them, as a
> non-existing open op will just be fine.

And here's a patch to do just that: remove all empty chardev
open/release methods. Based on the list compiled by Jonathan.

(and yeah, ip2_ipl_open is not technically empty at the source level,
but only at the binary level :))


Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Index: linux-2.6/arch/cris/arch-v10/drivers/i2c.c
===================================================================
--- linux-2.6.orig/arch/cris/arch-v10/drivers/i2c.c 2008-05-16 17:58:15.000000000 +0200
+++ linux-2.6/arch/cris/arch-v10/drivers/i2c.c 2008-05-16 17:58:19.000000000 +0200
@@ -563,18 +563,6 @@ i2c_readreg(unsigned char theSlave, unsi
return b;
}

-static int
-i2c_open(struct inode *inode, struct file *filp)
-{
- return 0;
-}
-
-static int
-i2c_release(struct inode *inode, struct file *filp)
-{
- return 0;
-}
-
/* Main device API. ioctl's to write or read to/from i2c registers.
*/

@@ -619,8 +607,6 @@ i2c_ioctl(struct inode *inode, struct fi
static const struct file_operations i2c_fops = {
.owner = THIS_MODULE,
.ioctl = i2c_ioctl,
- .open = i2c_open,
- .release = i2c_release,
};

int __init
Index: linux-2.6/arch/cris/arch-v32/drivers/i2c.c
===================================================================
--- linux-2.6.orig/arch/cris/arch-v32/drivers/i2c.c 2008-05-16 17:57:56.000000000 +0200
+++ linux-2.6/arch/cris/arch-v32/drivers/i2c.c 2008-05-16 17:58:07.000000000 +0200
@@ -633,18 +633,6 @@ i2c_readreg(unsigned char theSlave, unsi
return b;
}

-static int
-i2c_open(struct inode *inode, struct file *filp)
-{
- return 0;
-}
-
-static int
-i2c_release(struct inode *inode, struct file *filp)
-{
- return 0;
-}
-
/* Main device API. ioctl's to write or read to/from i2c registers.
*/

@@ -689,8 +677,6 @@ i2c_ioctl(struct inode *inode, struct fi
static const struct file_operations i2c_fops = {
.owner = THIS_MODULE,
.ioctl = i2c_ioctl,
- .open = i2c_open,
- .release = i2c_release,
};

static int __init i2c_init(void)
Index: linux-2.6/drivers/char/ip2/ip2main.c
===================================================================
--- linux-2.6.orig/drivers/char/ip2/ip2main.c 2008-05-16 17:59:17.000000000 +0200
+++ linux-2.6/drivers/char/ip2/ip2main.c 2008-05-16 17:59:37.000000000 +0200
@@ -203,7 +203,6 @@ static int set_serial_info(i2ChanStrPtr,
static ssize_t ip2_ipl_read(struct file *, char __user *, size_t, loff_t *);
static ssize_t ip2_ipl_write(struct file *, const char __user *, size_t, loff_t *);
static int ip2_ipl_ioctl(struct inode *, struct file *, UINT, ULONG);
-static int ip2_ipl_open(struct inode *, struct file *);

static int DumpTraceBuffer(char __user *, int);
static int DumpFifoBuffer( char __user *, int);
@@ -236,7 +235,6 @@ static const struct file_operations ip2_
.read = ip2_ipl_read,
.write = ip2_ipl_write,
.ioctl = ip2_ipl_ioctl,
- .open = ip2_ipl_open,
};

static unsigned long irq_counter = 0;
@@ -2918,58 +2916,6 @@ ip2_ipl_ioctl ( struct inode *pInode, st
return rc;
}

-/******************************************************************************/
-/* Function: ip2_ipl_open() */
-/* Parameters: Pointer to device inode */
-/* Pointer to file structure */
-/* Returns: Success or failure */
-/* */
-/* Description: */
-/* */
-/* */
-/******************************************************************************/
-static int
-ip2_ipl_open( struct inode *pInode, struct file *pFile )
-{
- unsigned int iplminor = iminor(pInode);
- i2eBordStrPtr pB;
- i2ChanStrPtr pCh;
-
-#ifdef IP2DEBUG_IPL
- printk (KERN_DEBUG "IP2IPL: open\n" );
-#endif
-
- switch(iplminor) {
- // These are the IPL devices
- case 0:
- case 4:
- case 8:
- case 12:
- break;
-
- // These are the status devices
- case 1:
- case 5:
- case 9:
- case 13:
- break;
-
- // These are the debug devices
- case 2:
- case 6:
- case 10:
- case 14:
- pB = i2BoardPtrTable[iplminor / 4];
- pCh = (i2ChanStrPtr) pB->i2eChannelPtr;
- break;
-
- // This is the trace device
- case 3:
- break;
- }
- return 0;
-}
-
static int
proc_ip2mem_show(struct seq_file *m, void *v)
{
Index: linux-2.6/drivers/isdn/hardware/eicon/divasi.c
===================================================================
--- linux-2.6.orig/drivers/isdn/hardware/eicon/divasi.c 2008-05-16 17:59:59.000000000 +0200
+++ linux-2.6/drivers/isdn/hardware/eicon/divasi.c 2008-05-16 18:00:13.000000000 +0200
@@ -74,7 +74,6 @@ static ssize_t um_idi_read(struct file *
static ssize_t um_idi_write(struct file *file, const char __user *buf,
size_t count, loff_t * offset);
static unsigned int um_idi_poll(struct file *file, poll_table * wait);
-static int um_idi_open(struct inode *inode, struct file *file);
static int um_idi_release(struct inode *inode, struct file *file);
static int remove_entity(void *entity);
static void diva_um_timer_function(unsigned long data);
@@ -136,7 +135,6 @@ static const struct file_operations diva
.read = um_idi_read,
.write = um_idi_write,
.poll = um_idi_poll,
- .open = um_idi_open,
.release = um_idi_release
};

@@ -398,12 +396,6 @@ static unsigned int um_idi_poll(struct f
return (POLLIN | POLLRDNORM);
}

-static int um_idi_open(struct inode *inode, struct file *file)
-{
- return (0);
-}
-
-
static int um_idi_release(struct inode *inode, struct file *file)
{
diva_um_idi_os_context_t *p_os;
Index: linux-2.6/drivers/isdn/hardware/eicon/divasmain.c
===================================================================
--- linux-2.6.orig/drivers/isdn/hardware/eicon/divasmain.c 2008-05-16 18:00:26.000000000 +0200
+++ linux-2.6/drivers/isdn/hardware/eicon/divasmain.c 2008-05-16 18:00:36.000000000 +0200
@@ -578,10 +578,6 @@ xdi_copy_from_user(void *os_handle, void
/*
* device node operations
*/
-static int divas_open(struct inode *inode, struct file *file)
-{
- return (0);
-}

static int divas_release(struct inode *inode, struct file *file)
{
@@ -667,7 +663,6 @@ static const struct file_operations diva
.read = divas_read,
.write = divas_write,
.poll = divas_poll,
- .open = divas_open,
.release = divas_release
};

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