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: Adriano dos Santos Fernandes <adrianosf@uol.com.br>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Adriano dos Santos Fernandes 2009-06-17 16:27:48 -07:00 committed by Linus Torvalds
parent 31a985fbb1
commit d6f47befdd

View file

@ -863,59 +863,58 @@ static const struct file_operations kmsg_fops = {
.write = kmsg_write, .write = kmsg_write,
}; };
static int memory_open(struct inode * inode, struct file * filp) 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 ret = 0;
int i;
lock_kernel(); lock_kernel();
switch (iminor(inode)) {
case 1: for (i = 0; i < ARRAY_SIZE(devlist); i++) {
filp->f_op = &mem_fops; if (devlist[i].minor == iminor(inode)) {
filp->f_op = devlist[i].fops;
if (devlist[i].dev_info) {
filp->f_mapping->backing_dev_info = filp->f_mapping->backing_dev_info =
&directly_mappable_cdev_bdi; devlist[i].dev_info;
break;
#ifdef CONFIG_DEVKMEM
case 2:
filp->f_op = &kmem_fops;
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;
break;
#endif
default:
unlock_kernel();
return -ENXIO;
} }
break;
}
}
if (i == ARRAY_SIZE(devlist))
ret = -ENXIO;
else
if (filp->f_op && filp->f_op->open) if (filp->f_op && filp->f_op->open)
ret = filp->f_op->open(inode,filp); ret = filp->f_op->open(inode, filp);
unlock_kernel(); unlock_kernel();
return ret; return ret;
} }
@ -924,30 +923,6 @@ static const struct file_operations memory_fops = {
.open = memory_open, /* just a selector for the real open */ .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 struct class *mem_class;
static int __init chr_dev_init(void) static int __init chr_dev_init(void)