block: Reduce the size of struct blk_integrity

The per-device properties in the blk_integrity structure were previously unsigned short. However, most of the values fit inside a char. The only exception is the data interval size and we can work around that by storing it as a power of two. This cuts the size of the dynamic portion of blk_integrity in half. Signed-off-by: Martin K. Petersen <[email protected]> Reported-by: Christoph Hellwig <[email protected]> Reviewed-by: Sagi Grimberg <[email protected]> Signed-off-by: Dan Williams <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
jljusten · Oct 21, 2015 · a48f041 · a48f041
1 parent 0f8087e
commit a48f041
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Showing 3 changed files with 9 additions and 9 deletions.
diff --git a/block/bio-integrity.c b/block/bio-integrity.c
@@ -202,7 +202,7 @@ EXPORT_SYMBOL(bio_integrity_enabled);
 static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi,
 						   unsigned int sectors)
 {
-	return sectors >> (ilog2(bi->interval) - 9);
+	return sectors >> (bi->interval_exp - 9);
 }
 
 static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
@@ -229,7 +229,7 @@ static int bio_integrity_process(struct bio *bio,
 		bip->bip_vec->bv_offset;
 
 	iter.disk_name = bio->bi_bdev->bd_disk->disk_name;
-	iter.interval = bi->interval;
+	iter.interval = 1 << bi->interval_exp;
 	iter.seed = bip_get_seed(bip);
 	iter.prot_buf = prot_buf;
 

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
@@ -155,10 +155,10 @@ int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
 	if (!b1 || !b2)
 		return -1;
 
-	if (b1->interval != b2->interval) {
+	if (b1->interval_exp != b2->interval_exp) {
 		pr_err("%s: %s/%s protection interval %u != %u\n",
 		       __func__, gd1->disk_name, gd2->disk_name,
-		       b1->interval, b2->interval);
+		       1 << b1->interval_exp, 1 << b2->interval_exp);
 		return -1;
 	}
 
@@ -440,7 +440,7 @@ int blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
 		kobject_uevent(&disk->integrity_kobj, KOBJ_ADD);
 
 		bi->flags |= BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE;
-		bi->interval = queue_logical_block_size(disk->queue);
+		bi->interval_exp = ilog2(queue_logical_block_size(disk->queue));
 		disk->integrity = bi;
 	} else
 		bi = disk->integrity;

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
@@ -1470,10 +1470,10 @@ struct blk_integrity_profile {
 
 struct blk_integrity {
 	struct blk_integrity_profile	*profile;
-	unsigned short			flags;
-	unsigned short			tuple_size;
-	unsigned short			interval;
-	unsigned short			tag_size;
+	unsigned char			flags;
+	unsigned char			tuple_size;
+	unsigned char			interval_exp;
+	unsigned char			tag_size;
 };
 
 extern bool blk_integrity_is_initialized(struct gendisk *);