[PATCH] add I/O error uevent for block devices

[Kay Sievers <kay.sievers@vrfy.org>]

For HAL we want to get notified about I/O errors of block devices.
This is especially useful for devices we are unable to poll and
therefore can't know if something goes wrong here.

Signed-off-by: David Zeuthen <david@fubar.dk>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>

===== fs/buffer.c 1.270 vs edited =====
--- 1.270/fs/buffer.c	2005-01-21 06:02:13 +01:00
+++ edited/fs/buffer.c	2005-02-17 22:56:05 +01:00
@@ -105,6 +105,7 @@ static void buffer_io_error(struct buffe
 	printk(KERN_ERR "Buffer I/O error on device %s, logical block %Lu\n",
 			bdevname(bh->b_bdev, b),
 			(unsigned long long)bh->b_blocknr);
+	kobject_uevent(&bh->b_bdev->bd_disk->kobj, KOBJ_IO_ERROR, NULL);
 }
 
 /*
@@ -550,7 +551,8 @@ static void end_buffer_async_read(struct
 		set_buffer_uptodate(bh);
 	} else {
 		clear_buffer_uptodate(bh);
-		buffer_io_error(bh);
+		if (printk_ratelimit())
+			buffer_io_error(bh);
 		SetPageError(page);
 	}
 
===== include/linux/kobject_uevent.h 1.6 vs edited =====
--- 1.6/include/linux/kobject_uevent.h	2004-11-08 20:43:30 +01:00
+++ edited/include/linux/kobject_uevent.h	2005-02-17 23:10:05 +01:00
@@ -29,6 +29,7 @@ enum kobject_action {
 	KOBJ_UMOUNT	= (__force kobject_action_t) 0x05,	/* umount event for block devices */
 	KOBJ_OFFLINE	= (__force kobject_action_t) 0x06,	/* offline event for hotplug devices */
 	KOBJ_ONLINE	= (__force kobject_action_t) 0x07,	/* online event for hotplug devices */
+	KOBJ_IO_ERROR	= (__force kobject_action_t) 0x08,	/* I/O error for devices */
 };
 
 
===== lib/kobject_uevent.c 1.18 vs edited =====
--- 1.18/lib/kobject_uevent.c	2005-01-08 06:44:13 +01:00
+++ edited/lib/kobject_uevent.c	2005-02-17 22:52:03 +01:00
@@ -44,6 +44,8 @@ static char *action_to_string(enum kobje
 		return "offline";
 	case KOBJ_ONLINE:
 		return "online";
+	case KOBJ_IO_ERROR:
+		return "io_error";
 	default:
 		return NULL;
 	}