diff options
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block | 13 | ||||
| -rw-r--r-- | block/genhd.c | 71 | ||||
| -rw-r--r-- | include/linux/genhd.h | 4 |
3 files changed, 88 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block index c1eb41cb9876..2b5d56127fce 100644 --- a/Documentation/ABI/testing/sysfs-block +++ b/Documentation/ABI/testing/sysfs-block @@ -206,3 +206,16 @@ Description: when a discarded area is read the discard_zeroes_data parameter will be set to one. Otherwise it will be 0 and the result of reading a discarded area is undefined. +What: /sys/block/<disk>/alias +Date: Aug 2011 +Contact: Nao Nishijima <nao.nishijima.xt@hitachi.com> +Description: + A raw device name of a disk does not always point a same disk + each boot-up time. Therefore, users have to use persistent + device names, which udev creates when the kernel finds a disk, + instead of raw device name. However, kernel doesn't show those + persistent names on its messages (e.g. dmesg). + This file can store an alias of the disk and it would be + appeared in kernel messages if it is set. A disk can have an + alias which length is up to 255bytes. Users can use alphabets, + numbers, "-" and "_" in alias name. This file is writeonce. 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, diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 02fa4697a0e5..6957350e122f 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -21,6 +21,8 @@ #define dev_to_part(device) container_of((device), struct hd_struct, __dev) #define disk_to_dev(disk) (&(disk)->part0.__dev) #define part_to_dev(part) (&((part)->__dev)) +#define alias_name(disk) ((disk)->alias ? (disk)->alias : \ + (disk)->disk_name) extern struct device_type part_type; extern struct kobject *block_depr; @@ -58,6 +60,7 @@ enum { #define DISK_MAX_PARTS 256 #define DISK_NAME_LEN 32 +#define ALIAS_LEN 256 #include <linux/major.h> #include <linux/device.h> @@ -162,6 +165,7 @@ struct gendisk { * disks that can't be partitioned. */ char disk_name[DISK_NAME_LEN]; /* name of major driver */ + char *alias; /* alias name of disk */ char *(*devnode)(struct gendisk *gd, mode_t *mode); unsigned int events; /* supported events */ |