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Commit d6f47bef authored by Adriano dos Santos Fernandes's avatar Adriano dos Santos Fernandes Committed by Linus Torvalds
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drivers/char/mem.c: memory_open() cleanup: lookup minor device number from devlist 



memory_open() ignores devlist and does a switch for each item, duplicating
code and conditional definitions.

Clean it up by adding backing_dev_info to devlist and use it to lookup for
the minor device.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarAdriano dos Santos Fernandes <adrianosf@uol.com.br>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 31a985fb

drivers/char/mem.c

+45 −70
Original line number Diff line number Diff line
@@ -863,59 +863,58 @@ static const struct file_operations kmsg_fops = { 
	.write =	kmsg_write,

};



static const struct {

	unsigned int		minor;

	char			*name;

	umode_t			mode;

	const struct file_operations	*fops;

	struct backing_dev_info	*dev_info;

} devlist[] = { /* list of minor devices */

	{1, "mem",     S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops,

		&directly_mappable_cdev_bdi},

#ifdef CONFIG_DEVKMEM

	{2, "kmem",    S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops,

		&directly_mappable_cdev_bdi},

#endif

	{3, "null",    S_IRUGO | S_IWUGO,           &null_fops, NULL},

#ifdef CONFIG_DEVPORT

	{4, "port",    S_IRUSR | S_IWUSR | S_IRGRP, &port_fops, NULL},

#endif

	{5, "zero",    S_IRUGO | S_IWUGO,           &zero_fops, &zero_bdi},

	{7, "full",    S_IRUGO | S_IWUGO,           &full_fops, NULL},

	{8, "random",  S_IRUGO | S_IWUSR,           &random_fops, NULL},

	{9, "urandom", S_IRUGO | S_IWUSR,           &urandom_fops, NULL},

	{11,"kmsg",    S_IRUGO | S_IWUSR,           &kmsg_fops, NULL},

#ifdef CONFIG_CRASH_DUMP

	{12,"oldmem",    S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops, NULL},

#endif

};



static int memory_open(struct inode *inode, struct file *filp)

{

	int ret = 0;

	int i;



	lock_kernel();

	switch (iminor(inode)) {

		case 1:

			filp->f_op = &mem_fops;

			filp->f_mapping->backing_dev_info =

				&directly_mappable_cdev_bdi;

			break;

#ifdef CONFIG_DEVKMEM

		case 2:

			filp->f_op = &kmem_fops;



	for (i = 0; i < ARRAY_SIZE(devlist); i++) {

		if (devlist[i].minor == iminor(inode)) {

			filp->f_op = devlist[i].fops;

			if (devlist[i].dev_info) {

				filp->f_mapping->backing_dev_info =

				&directly_mappable_cdev_bdi;

			break;

#endif

		case 3:

			filp->f_op = &null_fops;

			break;

#ifdef CONFIG_DEVPORT

		case 4:

			filp->f_op = &port_fops;

			break;

#endif

		case 5:

			filp->f_mapping->backing_dev_info = &zero_bdi;

			filp->f_op = &zero_fops;

			break;

		case 7:

			filp->f_op = &full_fops;

			break;

		case 8:

			filp->f_op = &random_fops;

			break;

		case 9:

			filp->f_op = &urandom_fops;

			break;

		case 11:

			filp->f_op = &kmsg_fops;

			break;

#ifdef CONFIG_CRASH_DUMP

		case 12:

			filp->f_op = &oldmem_fops;

					devlist[i].dev_info;

			}



			break;

#endif

		default:

			unlock_kernel();

			return -ENXIO;

		}

	}



	if (i == ARRAY_SIZE(devlist))

		ret = -ENXIO;

	else

		if (filp->f_op && filp->f_op->open)

			ret = filp->f_op->open(inode, filp);



	unlock_kernel();

	return ret;

}
@@ -924,30 +923,6 @@ static const struct file_operations memory_fops = { 
	.open		= memory_open,	/* just a selector for the real open */

};



static const struct {

	unsigned int		minor;

	char			*name;

	umode_t			mode;

	const struct file_operations	*fops;

} devlist[] = { /* list of minor devices */

	{1, "mem",     S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},

#ifdef CONFIG_DEVKMEM

	{2, "kmem",    S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},

#endif

	{3, "null",    S_IRUGO | S_IWUGO,           &null_fops},

#ifdef CONFIG_DEVPORT

	{4, "port",    S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},

#endif

	{5, "zero",    S_IRUGO | S_IWUGO,           &zero_fops},

	{7, "full",    S_IRUGO | S_IWUGO,           &full_fops},

	{8, "random",  S_IRUGO | S_IWUSR,           &random_fops},

	{9, "urandom", S_IRUGO | S_IWUSR,           &urandom_fops},

	{11,"kmsg",    S_IRUGO | S_IWUSR,           &kmsg_fops},

#ifdef CONFIG_CRASH_DUMP

	{12,"oldmem",    S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},

#endif

};



static struct class *mem_class;



static int __init chr_dev_init(void)