[PATCH] dm: Data integrity support

[PATCH] dm: Data integrity support

[Martin K. Petersen]

This patch provides support for data integrity passthrough in the device
mapper.

 - If one or more component devices support integrity an integrity
   profile is preallocated for the DM device.

 - If all component devices have compatible profiles the DM device is
   flagged as capable.

 - Handle integrity metadata when splitting and cloning bios.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

---

This patch requires a change in Jens' for-linus branch that adds a GFP
mask to bio_integrity_clone() and obsoletes the bio_set argument.


diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c
--- a/drivers/md/dm-ioctl.c
+++ b/drivers/md/dm-ioctl.c
@@ -1046,6 +1046,19 @@ static int populate_table(struct dm_tabl
 	return dm_table_complete(table);
 }
 
+static int table_prealloc_integrity(struct dm_table *t,
+				    struct mapped_device *md)
+{
+	struct list_head *devices = dm_table_get_devices(t);
+	struct dm_dev_internal *dd;
+
+	list_for_each_entry(dd, devices, list)
+		if (bdev_get_integrity(dd->dm_dev.bdev))
+			return blk_integrity_register(dm_disk(md), NULL);
+
+	return 0;
+}
+
 static int table_load(struct dm_ioctl *param, size_t param_size)
 {
 	int r;
@@ -1067,6 +1080,14 @@ static int table_load(struct dm_ioctl *p
 		goto out;
 	}
 
+	r = table_prealloc_integrity(t, md);
+	if (r) {
+		DMERR("%s: could not register integrity profile.",
+		      dm_device_name(md));
+		dm_table_destroy(t);
+		goto out;
+	}
+
 	down_write(&_hash_lock);
 	hc = dm_get_mdptr(md);
 	if (!hc || hc->md != md) {
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -877,6 +877,45 @@ struct dm_target *dm_table_find_target(s
 	return &t->targets[(KEYS_PER_NODE * n) + k];
 }
 
+/*
+ * Set the integrity profile for this device if all devices used have
+ * matching profiles.
+ */
+static void dm_table_set_integrity(struct dm_table *t)
+{
+	struct list_head *devices = dm_table_get_devices(t);
+	struct dm_dev_internal *prev = NULL, *dd = NULL;
+
+	if (!blk_get_integrity(dm_disk(t->md)))
+		return;
+
+	list_for_each_entry(dd, devices, list) {
+		if (prev &&
+		    blk_integrity_compare(prev->dm_dev.bdev->bd_disk,
+					  dd->dm_dev.bdev->bd_disk) < 0) {
+			DMWARN("%s: integrity not set: %s and %s mismatch",
+			       dm_device_name(t->md),
+			       prev->dm_dev.bdev->bd_disk->disk_name,
+			       dd->dm_dev.bdev->bd_disk->disk_name);
+			goto no_integrity;
+		}
+		prev = dd;
+	}
+
+	if (!prev || !bdev_get_integrity(prev->dm_dev.bdev))
+		goto no_integrity;
+
+	blk_integrity_register(dm_disk(t->md),
+			       bdev_get_integrity(prev->dm_dev.bdev));
+
+	return;
+
+no_integrity:
+	blk_integrity_register(dm_disk(t->md), NULL);
+
+	return;
+}
+
 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q)
 {
 	/*
@@ -897,6 +936,7 @@ void dm_table_set_restrictions(struct dm
 	else
 		queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q);
 
+	dm_table_set_integrity(t);
 }
 
 unsigned int dm_table_get_num_targets(struct dm_table *t)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -703,6 +703,12 @@ static struct bio *split_bvec(struct bio
 	clone->bi_io_vec->bv_len = clone->bi_size;
 	clone->bi_flags |= 1 << BIO_CLONED;
 
+	if (bio_integrity(bio)) {
+		bio_integrity_clone(clone, bio, GFP_NOIO);
+		bio_integrity_trim(clone,
+				   bio_sector_offset(bio, idx, offset), len);
+	}
+
 	return clone;
 }
 
@@ -724,6 +730,14 @@ static struct bio *clone_bio(struct bio 
 	clone->bi_size = to_bytes(len);
 	clone->bi_flags &= ~(1 << BIO_SEG_VALID);
 
+	if (bio_integrity(bio)) {
+		bio_integrity_clone(clone, bio, GFP_NOIO);
+
+		if (idx != bio->bi_idx || clone->bi_size < bio->bi_size)
+			bio_integrity_trim(clone,
+					   bio_sector_offset(bio, idx, 0), len);
+	}
+
 	return clone;
 }
 
@@ -1191,6 +1205,7 @@ static void free_dev(struct mapped_devic
 	mempool_destroy(md->tio_pool);
 	mempool_destroy(md->io_pool);
 	bioset_free(md->bs);
+	blk_integrity_unregister(md->disk);
 	del_gendisk(md->disk);
 	free_minor(minor);
 

Re: [PATCH] dm: Data integrity support

[Alasdair G Kergon]

On Mon, Mar 09, 2009 at 11:46:05PM -0400, Martin K. Petersen wrote:
> This patch requires a change in Jens' for-linus branch that adds a GFP
> mask to bio_integrity_clone() and obsoletes the bio_set argument.
 
I've not had the chance to track down that patch, but if you can note
in this thread when it's hit Linus's tree, then I'll submit this one
behind it.

Alasdair
-- 
agk@redhat.com

Re: Re: [PATCH] dm: Data integrity support

[Mike Snitzer]

Alasdair G Kergon wrote:
> On Mon, Mar 09, 2009 at 11:46:05PM -0400, Martin K. Petersen wrote:
>> This patch requires a change in Jens' for-linus branch that adds a GFP
>> mask to bio_integrity_clone() and obsoletes the bio_set argument.
>  
> I've not had the chance to track down that patch, but if you can note
> in this thread when it's hit Linus's tree, then I'll submit this one
> behind it.

Seems that change has been committed to Linus's tree with commit:
87092698c665e0a358caf9825ae13114343027e8

Mike

Re: Re: [PATCH] dm: Data integrity support

[Martin K. Petersen]

>>>>> "Mike" == Mike Snitzer <snitzer@redhat.com> writes:

>> This patch requires a change in Jens' for-linus branch that adds a
>> GFP mask to bio_integrity_clone() and obsoletes the bio_set argument.
>> 

> I've not had the chance to track down that patch, but if you can note
> in this thread when it's hit Linus's tree, then I'll submit this one
> behind it.

Mike> Seems that change has been committed to Linus's tree with commit:
Mike> 87092698c665e0a358caf9825ae13114343027e8

The DM integrity patch depends on the following change sets:

	87092698c665e0a358caf9825ae13114343027e8

	6d2a78e783416ba99e36beb1d4395b785b34e867

Both are in Linus' tree.

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: Re: [PATCH] dm: Data integrity support

[Alasdair G Kergon]

I've pushed this to linux-next now and will include it in the next batch
I push regardless of what is to be done about the allocation problem.

Alasdair
-- 
agk@redhat.com

Re: Re: [PATCH] dm: Data integrity support

[Martin K. Petersen]

>>>>> "Alasdair" == Alasdair G Kergon <agk@redhat.com> writes:

Alasdair> I've pushed this to linux-next now and will include it in the
Alasdair> next batch I push regardless of what is to be done about the
Alasdair> allocation problem.

Great, thanks!  I'll get my allocation fix out later today.

-- 
Martin K. Petersen	Oracle Linux Engineering