From 667be1e757f5684576d01d7402907a2489b1402f Mon Sep 17 00:00:00 2001
From: Ed Cashin <ecashin@coraid.com>
Date: Mon, 17 Dec 2012 16:03:42 -0800
Subject: [PATCH] aoe: provide ATA identify device content to user on request

Make the aoe driver follow expected behavior when the user uses ioctl to
get the ATA device identify information, allowing access to model, serial
number, etc.

Signed-off-by: Ed Cashin <ecashin@coraid.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 drivers/block/aoe/aoe.h    |  1 +
 drivers/block/aoe/aoeblk.c | 30 ++++++++++++++++++++++++++++++
 drivers/block/aoe/aoecmd.c | 16 ++++++++++++++++
 3 files changed, 47 insertions(+)

diff --git a/drivers/block/aoe/aoe.h b/drivers/block/aoe/aoe.h
index 536942b46ab6..f6e0c03fe7b2 100644
--- a/drivers/block/aoe/aoe.h
+++ b/drivers/block/aoe/aoe.h
@@ -169,6 +169,7 @@ struct aoedev {
 	struct aoetgt *htgt;	/* target needing rexmit assistance */
 	ulong ntargets;
 	ulong kicked;
+	char ident[512];
 };
 
 /* kthread tracking */
diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c
index 56736cd5f3fe..7ba0fcf7b06b 100644
--- a/drivers/block/aoe/aoeblk.c
+++ b/drivers/block/aoe/aoeblk.c
@@ -17,6 +17,7 @@
 #include <linux/mutex.h>
 #include <linux/export.h>
 #include <linux/moduleparam.h>
+#include <scsi/sg.h>
 #include "aoe.h"
 
 static DEFINE_MUTEX(aoeblk_mutex);
@@ -212,9 +213,38 @@ aoeblk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return 0;
 }
 
+static int
+aoeblk_ioctl(struct block_device *bdev, fmode_t mode, uint cmd, ulong arg)
+{
+	struct aoedev *d;
+
+	if (!arg)
+		return -EINVAL;
+
+	d = bdev->bd_disk->private_data;
+	if ((d->flags & DEVFL_UP) == 0) {
+		pr_err("aoe: disk not up\n");
+		return -ENODEV;
+	}
+
+	if (cmd == HDIO_GET_IDENTITY) {
+		if (!copy_to_user((void __user *) arg, &d->ident,
+			sizeof(d->ident)))
+			return 0;
+		return -EFAULT;
+	}
+
+	/* udev calls scsi_id, which uses SG_IO, resulting in noise */
+	if (cmd != SG_IO)
+		pr_info("aoe: unknown ioctl 0x%x\n", cmd);
+
+	return -ENOTTY;
+}
+
 static const struct block_device_operations aoe_bdops = {
 	.open = aoeblk_open,
 	.release = aoeblk_release,
+	.ioctl = aoeblk_ioctl,
 	.getgeo = aoeblk_getgeo,
 	.owner = THIS_MODULE,
 };
diff --git a/drivers/block/aoe/aoecmd.c b/drivers/block/aoe/aoecmd.c
index 3ce01f6b3a5d..c4ff70b61e7e 100644
--- a/drivers/block/aoe/aoecmd.c
+++ b/drivers/block/aoe/aoecmd.c
@@ -798,6 +798,17 @@ aoecmd_sleepwork(struct work_struct *work)
 	}
 }
 
+static void
+ata_ident_fixstring(u16 *id, int ns)
+{
+	u16 s;
+
+	while (ns-- > 0) {
+		s = *id;
+		*id++ = s >> 8 | s << 8;
+	}
+}
+
 static void
 ataid_complete(struct aoedev *d, struct aoetgt *t, unsigned char *id)
 {
@@ -833,6 +844,11 @@ ataid_complete(struct aoedev *d, struct aoetgt *t, unsigned char *id)
 		d->geo.sectors = get_unaligned_le16(&id[56 << 1]);
 	}
 
+	ata_ident_fixstring((u16 *) &id[10<<1], 10);	/* serial */
+	ata_ident_fixstring((u16 *) &id[23<<1], 4);	/* firmware */
+	ata_ident_fixstring((u16 *) &id[27<<1], 20);	/* model */
+	memcpy(d->ident, id, sizeof(d->ident));
+
 	if (d->ssize != ssize)
 		printk(KERN_INFO
 			"aoe: %pm e%ld.%d v%04x has %llu sectors\n",
-- 
2.30.2