block: Inline blk_integrity in struct gendisk

Up until now the_integrity profile has been dynamically allocated and
attached to struct gendisk after the disk has been made active.

This causes problems because NVMe devices need to register the profile
prior to the partition table being read due to a mandatory metadata
buffer requirement. In addition, DM goes through hoops to deal with
preallocating, but not initializing integrity profiles.

Since the integrity profile is small (4 bytes + a pointer), Christoph
suggested moving it to struct gendisk proper. This requires several
changes:

 - Moving the blk_integrity definition to genhd.h.

 - Inlining blk_integrity in struct gendisk.

 - Removing the dynamic allocation code.

 - Adding helper functions which allow gendisk to set up and tear down
   the integrity sysfs dir when a disk is added/deleted.

 - Adding a blk_integrity_revalidate() callback for updating the stable
   pages bdi setting.

 - The calls that depend on whether a device has an integrity profile or
   not now key off of the bi->profile pointer.

 - Simplifying the integrity support routines in DM (Mike Snitzer).

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

3 files changed, 61 insertions, 102 deletions

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 7a96f57ed1952..4615a33867985 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -30,10 +30,6 @@
 
 #include "blk.h"
 
-static struct kmem_cache *integrity_cachep;
-
-static const char *bi_unsupported_name = "unsupported";
-
 /**
  * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
  * @q:		request queue
@@ -146,13 +142,13 @@ EXPORT_SYMBOL(blk_rq_map_integrity_sg);
  */
 int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
 {
-	struct blk_integrity *b1 = gd1->integrity;
-	struct blk_integrity *b2 = gd2->integrity;
+	struct blk_integrity *b1 = &gd1->integrity;
+	struct blk_integrity *b2 = &gd2->integrity;
 
-	if (!b1 && !b2)
+	if (!b1->profile && !b2->profile)
 		return 0;
 
-	if (!b1 || !b2)
+	if (!b1->profile || !b2->profile)
 		return -1;
 
 	if (b1->interval_exp != b2->interval_exp) {
@@ -163,21 +159,21 @@ int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
 	}
 
 	if (b1->tuple_size != b2->tuple_size) {
-		printk(KERN_ERR "%s: %s/%s tuple sz %u != %u\n", __func__,
+		pr_err("%s: %s/%s tuple sz %u != %u\n", __func__,
 		       gd1->disk_name, gd2->disk_name,
 		       b1->tuple_size, b2->tuple_size);
 		return -1;
 	}
 
 	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
-		printk(KERN_ERR "%s: %s/%s tag sz %u != %u\n", __func__,
+		pr_err("%s: %s/%s tag sz %u != %u\n", __func__,
 		       gd1->disk_name, gd2->disk_name,
 		       b1->tag_size, b2->tag_size);
 		return -1;
 	}
 
 	if (b1->profile != b2->profile) {
-		printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__,
+		pr_err("%s: %s/%s type %s != %s\n", __func__,
 		       gd1->disk_name, gd2->disk_name,
 		       b1->profile->name, b2->profile->name);
 		return -1;
@@ -250,7 +246,7 @@ static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
 				   char *page)
 {
 	struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
-	struct blk_integrity *bi = blk_get_integrity(disk);
+	struct blk_integrity *bi = &disk->integrity;
 	struct integrity_sysfs_entry *entry =
 		container_of(attr, struct integrity_sysfs_entry, attr);
 
@@ -262,7 +258,7 @@ static ssize_t integrity_attr_store(struct kobject *kobj,
 				    size_t count)
 {
 	struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
-	struct blk_integrity *bi = blk_get_integrity(disk);
+	struct blk_integrity *bi = &disk->integrity;
 	struct integrity_sysfs_entry *entry =
 		container_of(attr, struct integrity_sysfs_entry, attr);
 	ssize_t ret = 0;
@@ -275,7 +271,7 @@ static ssize_t integrity_attr_store(struct kobject *kobj,
 
 static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
 {
-	if (bi != NULL && bi->profile->name != NULL)
+	if (bi->profile && bi->profile->name)
 		return sprintf(page, "%s\n", bi->profile->name);
 	else
 		return sprintf(page, "none\n");
@@ -283,18 +279,13 @@ static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
 
 static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
 {
-	if (bi != NULL)
-		return sprintf(page, "%u\n", bi->tag_size);
-	else
-		return sprintf(page, "0\n");
+	return sprintf(page, "%u\n", bi->tag_size);
 }
 
 static ssize_t integrity_interval_show(struct blk_integrity *bi, char *page)
 {
-	if (bi != NULL)
-		return sprintf(page, "%u\n", 1 << bi->interval_exp);
-	else
-		return sprintf(page, "0\n");
+	return sprintf(page, "%u\n",
+		       bi->interval_exp ? 1 << bi->interval_exp : 0);
 }
 
 static ssize_t integrity_verify_store(struct blk_integrity *bi,
@@ -388,113 +379,78 @@ static const struct sysfs_ops integrity_ops = {
 	.store	= &integrity_attr_store,
 };
 
-static int __init blk_dev_integrity_init(void)
-{
-	integrity_cachep = kmem_cache_create("blkdev_integrity",
-					     sizeof(struct blk_integrity),
-					     0, SLAB_PANIC, NULL);
-	return 0;
-}
-subsys_initcall(blk_dev_integrity_init);
-
-static void blk_integrity_release(struct kobject *kobj)
-{
-	struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
-	struct blk_integrity *bi = blk_get_integrity(disk);
-
-	kmem_cache_free(integrity_cachep, bi);
-}
-
 static struct kobj_type integrity_ktype = {
 	.default_attrs	= integrity_attrs,
 	.sysfs_ops	= &integrity_ops,
-	.release	= blk_integrity_release,
 };
 
-bool blk_integrity_is_initialized(struct gendisk *disk)
-{
-	struct blk_integrity *bi = blk_get_integrity(disk);
-
-	return (bi && bi->profile->name && strcmp(bi->profile->name,
-						  bi_unsupported_name) != 0);
-}
-EXPORT_SYMBOL(blk_integrity_is_initialized);
-
 /**
  * blk_integrity_register - Register a gendisk as being integrity-capable
  * @disk:	struct gendisk pointer to make integrity-aware
- * @template:	optional integrity profile to register
+ * @template:	block integrity profile to register
  *
- * Description: When a device needs to advertise itself as being able
- * to send/receive integrity metadata it must use this function to
- * register the capability with the block layer.  The template is a
- * blk_integrity struct with values appropriate for the underlying
- * hardware.  If template is NULL the new profile is allocated but
- * not filled out. See Documentation/block/data-integrity.txt.
+ * Description: When a device needs to advertise itself as being able to
+ * send/receive integrity metadata it must use this function to register
+ * the capability with the block layer. The template is a blk_integrity
+ * struct with values appropriate for the underlying hardware. See
+ * Documentation/block/data-integrity.txt.
  */
-int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
+void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
 {
-	struct blk_integrity *bi;
-
-	BUG_ON(disk == NULL);
+	struct blk_integrity *bi = &disk->integrity;
 
-	if (disk->integrity == NULL) {
-		bi = kmem_cache_alloc(integrity_cachep,
-				      GFP_KERNEL | __GFP_ZERO);
-		if (!bi)
-			return -1;
+	bi->flags = BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE |
+		template->flags;
+	bi->interval_exp = ilog2(queue_logical_block_size(disk->queue));
+	bi->profile = template->profile;
+	bi->tuple_size = template->tuple_size;
+	bi->tag_size = template->tag_size;
 
-		if (kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,
-					 &disk_to_dev(disk)->kobj,
-					 "%s", "integrity")) {
-			kmem_cache_free(integrity_cachep, bi);
-			return -1;
-		}
-
-		kobject_uevent(&disk->integrity_kobj, KOBJ_ADD);
-
-		bi->flags |= BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE;
-		bi->interval_exp = ilog2(queue_logical_block_size(disk->queue));
-		disk->integrity = bi;
-	} else
-		bi = disk->integrity;
-
-	/* Use the provided profile as template */
-	if (template != NULL) {
-		bi->profile = template->profile;
-		bi->tuple_size = template->tuple_size;
-		bi->tag_size = template->tag_size;
-		bi->flags |= template->flags;
-	} else
-		bi->profile->name = bi_unsupported_name;
-
-	disk->queue->backing_dev_info.capabilities |= BDI_CAP_STABLE_WRITES;
-
-	return 0;
+	blk_integrity_revalidate(disk);
 }
 EXPORT_SYMBOL(blk_integrity_register);
 
 /**
- * blk_integrity_unregister - Remove block integrity profile
- * @disk:	disk whose integrity profile to deallocate
+ * blk_integrity_unregister - Unregister block integrity profile
+ * @disk:	disk whose integrity profile to unregister
  *
- * Description: This function frees all memory used by the block
- * integrity profile.  To be called at device teardown.
+ * Description: This function unregisters the integrity capability from
+ * a block device.
  */
 void blk_integrity_unregister(struct gendisk *disk)
 {
-	struct blk_integrity *bi;
+	blk_integrity_revalidate(disk);
+	memset(&disk->integrity, 0, sizeof(struct blk_integrity));
+}
+EXPORT_SYMBOL(blk_integrity_unregister);
 
-	if (!disk || !disk->integrity)
+void blk_integrity_revalidate(struct gendisk *disk)
+{
+	struct blk_integrity *bi = &disk->integrity;
+
+	if (!(disk->flags & GENHD_FL_UP))
 		return;
 
-	disk->queue->backing_dev_info.capabilities &= ~BDI_CAP_STABLE_WRITES;
+	if (bi->profile)
+		disk->queue->backing_dev_info.capabilities |=
+			BDI_CAP_STABLE_WRITES;
+	else
+		disk->queue->backing_dev_info.capabilities &=
+			~BDI_CAP_STABLE_WRITES;
+}
 
-	bi = disk->integrity;
+void blk_integrity_add(struct gendisk *disk)
+{
+	if (kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,
+				 &disk_to_dev(disk)->kobj, "%s", "integrity"))
+		return;
 
+	kobject_uevent(&disk->integrity_kobj, KOBJ_ADD);
+}
+
+void blk_integrity_del(struct gendisk *disk)
+{
 	kobject_uevent(&disk->integrity_kobj, KOBJ_REMOVE);
 	kobject_del(&disk->integrity_kobj);
 	kobject_put(&disk->integrity_kobj);
-	disk->integrity = NULL;
 }
-EXPORT_SYMBOL(blk_integrity_unregister);
diff --git a/block/genhd.c b/block/genhd.c
index 0c706f33a599a..e5cafa51567c9 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -630,6 +630,7 @@ void add_disk(struct gendisk *disk)
 	WARN_ON(retval);
 
 	disk_add_events(disk);
+	blk_integrity_add(disk);
 }
 EXPORT_SYMBOL(add_disk);
 
@@ -638,6 +639,7 @@ void del_gendisk(struct gendisk *disk)
 	struct disk_part_iter piter;
 	struct hd_struct *part;
 
+	blk_integrity_del(disk);
 	disk_del_events(disk);
 
 	/* invalidate stuff */
diff --git a/block/partition-generic.c b/block/partition-generic.c
index e7711133284e1..3b030157ec85c 100644
--- a/block/partition-generic.c
+++ b/block/partition-generic.c
@@ -428,6 +428,7 @@ rescan:
 
 	if (disk->fops->revalidate_disk)
 		disk->fops->revalidate_disk(disk);
+	blk_integrity_revalidate(disk);
 	check_disk_size_change(disk, bdev);
 	bdev->bd_invalidated = 0;
 	if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))