Merge branch 'for-3.2/core' of git://git.kernel.dk/linux-block

[cascardo/linux.git] / block / genhd.c

diff --git a/block/genhd.c b/block/genhd.c
index d261b73..024fc39 100644 (file)
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -19,6 +19,7 @@
 #include <linux/mutex.h>
 #include <linux/idr.h>
 #include <linux/log2.h>
+#include <linux/ctype.h>
 
 #include "blk.h"
 
@@ -915,6 +916,74 @@ static int __init genhd_device_init(void)
 
 subsys_initcall(genhd_device_init);
 
+static ssize_t alias_show(struct device *dev,
+                              struct device_attribute *attr, char *buf)
+{
+       struct gendisk *disk = dev_to_disk(dev);
+       ssize_t ret = 0;
+
+       if (disk->alias)
+               ret = snprintf(buf, ALIAS_LEN, "%s\n", disk->alias);
+       return ret;
+}
+
+static ssize_t alias_store(struct device *dev, struct device_attribute *attr,
+                          const char *buf, size_t count)
+{
+       struct gendisk *disk = dev_to_disk(dev);
+       char *alias;
+       char *envp[] = { NULL, NULL };
+       unsigned char c;
+       int i;
+       ssize_t ret = count;
+
+       if (!count)
+               return -EINVAL;
+
+       if (count >= ALIAS_LEN) {
+               printk(KERN_ERR "alias: alias is too long\n");
+               return -EINVAL;
+       }
+
+       /* Validation check */
+       for (i = 0; i < count; i++) {
+               c = buf[i];
+               if (i == count - 1 && c == '\n')
+                       break;
+               if (!isalnum(c) && c != '_' && c != '-') {
+                       printk(KERN_ERR "alias: invalid alias\n");
+                       return -EINVAL;
+               }
+       }
+
+       if (disk->alias) {
+               printk(KERN_INFO "alias: %s is already assigned (%s)\n",
+                      disk->disk_name, disk->alias);
+               return -EINVAL;
+       }
+
+       alias = kasprintf(GFP_KERNEL, "%s", buf);
+       if (!alias)
+               return -ENOMEM;
+
+       if (alias[count - 1] == '\n')
+               alias[count - 1] = '\0';
+
+       envp[0] = kasprintf(GFP_KERNEL, "ALIAS=%s", alias);
+       if (!envp[0]) {
+               kfree(alias);
+               return -ENOMEM;
+       }
+
+       disk->alias = alias;
+       printk(KERN_INFO "alias: assigned %s to %s\n", alias, disk->disk_name);
+
+       kobject_uevent_env(&dev->kobj, KOBJ_ADD, envp);
+
+       kfree(envp[0]);
+       return ret;
+}
+
 static ssize_t disk_range_show(struct device *dev,
                               struct device_attribute *attr, char *buf)
 {
@@ -974,6 +1043,7 @@ static ssize_t disk_discard_alignment_show(struct device *dev,
        return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
 }
 
+static DEVICE_ATTR(alias, S_IRUGO|S_IWUSR, alias_show, alias_store);
 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
 static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
@@ -996,6 +1066,7 @@ static struct device_attribute dev_attr_fail_timeout =
 #endif
 
 static struct attribute *disk_attrs[] = {
+       &dev_attr_alias.attr,
        &dev_attr_range.attr,
        &dev_attr_ext_range.attr,
        &dev_attr_removable.attr,