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authorNao Nishijima <nao.nishijima.xt@hitachi.com>2011-08-25 18:04:06 +0900
committerJames Bottomley <JBottomley@Parallels.com>2011-08-29 00:16:19 -0700
commita72c5e5eb738033938ab30d6a634b74d1d060f10 (patch)
tree72cea6d75a62f7003d55f8a754c2d17149ada85f /block
parent76e4e12ff2b3ef86773989fd897b194eb38016e6 (diff)
downloadkernel-a72c5e5eb738033938ab30d6a634b74d1d060f10.tar.gz
[SCSI] genhd: add a new attribute "alias" in gendisk
This patch allows the user to set an "alias" of the disk via sysfs interface. This patch only adds a new attribute "alias" in gendisk structure. To show the alias instead of the device name in kernel messages, we need to revise printk messages and use alias_name() in them. Example: (current) printk("disk name is %s\n", disk->disk_name); (new) printk("disk name is %s\n", alias_name(disk)); Users can use alphabets, numbers, '-' and '_' in "alias" attribute. A disk can have an "alias" which length is up to 255 bytes. This attribute is write-once. Suggested-by: James Bottomley <James.Bottomley@HansenPartnership.com> Suggested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Nao Nishijima <nao.nishijima.xt@hitachi.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Diffstat (limited to 'block')
-rw-r--r--block/genhd.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/block/genhd.c b/block/genhd.c
index e2f67902dd02..94855a9717de 100644
--- 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"
@@ -909,6 +910,74 @@ 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)
{
@@ -968,6 +1037,7 @@ 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);
@@ -990,6 +1060,7 @@ 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,