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>
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index f96d0be..afa8813 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -863,59 +863,58 @@
.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 i;
lock_kernel();
- switch (iminor(inode)) {
- case 1:
- filp->f_op = &mem_fops;
- filp->f_mapping->backing_dev_info =
- &directly_mappable_cdev_bdi;
+
+ 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;
-#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;
+ }
}
- 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 @@
.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)