From d6f47befdd7483cd1e14a7ae76ef22f7f9722c90 Mon Sep 17 00:00:00 2001 From: Adriano dos Santos Fernandes Date: Wed, 17 Jun 2009 16:27:48 -0700 Subject: 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/mem.c | 115 +++++++++++++++++++++-------------------------------- 1 file changed, 45 insertions(+), 70 deletions(-) (limited to 'drivers/char/mem.c') diff --git a/drivers/char/mem.c b/drivers/char/mem.c index f96d0bef855e..afa8813e737a 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -863,59 +863,58 @@ static const struct file_operations kmsg_fops = { .write = kmsg_write, }; -static int memory_open(struct inode * inode, struct file * filp) -{ - int ret = 0; - - lock_kernel(); - switch (iminor(inode)) { - case 1: - filp->f_op = &mem_fops; - filp->f_mapping->backing_dev_info = - &directly_mappable_cdev_bdi; - break; +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 - case 2: - filp->f_op = &kmem_fops; - filp->f_mapping->backing_dev_info = - &directly_mappable_cdev_bdi; - break; + {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops, + &directly_mappable_cdev_bdi}, #endif - case 3: - filp->f_op = &null_fops; - break; + {3, "null", S_IRUGO | S_IWUGO, &null_fops, NULL}, #ifdef CONFIG_DEVPORT - case 4: - filp->f_op = &port_fops; - break; + {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops, NULL}, #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; + {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 - case 12: - filp->f_op = &oldmem_fops; - break; + {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops, NULL}, #endif - default: - unlock_kernel(); - return -ENXIO; +}; + +static int memory_open(struct inode *inode, struct file *filp) +{ + int ret = 0; + int i; + + lock_kernel(); + + 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 = + devlist[i].dev_info; + } + + break; + } } - if (filp->f_op && filp->f_op->open) - ret = filp->f_op->open(inode,filp); + + 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) -- cgit v1.2.3