[PATCH 39/42] block: shrink bio/request fields

[mchristi@redhat.com]

From: Mike Christie <mchristi@redhat.com>

bi_op only needed to be a int for temp compat reasons, so
this patch shrinks it to u8.

There is no need for bi_rw to be so large now, so that is
reduced to a unsigned int and bi_ioprio is just put in
its own field.

Signed-off-by: Mike Christie <mchristi@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
---
 block/blk-core.c           |  2 +-
 drivers/md/dm-flakey.c     |  2 +-
 drivers/md/raid5.c         | 13 +++++++------
 fs/btrfs/check-integrity.c |  4 ++--
 fs/btrfs/inode.c           |  2 +-
 include/linux/bio.h        | 13 ++-----------
 include/linux/blk_types.h  | 11 +++--------
 include/linux/blkdev.h     |  2 +-
 8 files changed, 18 insertions(+), 31 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index ccf2056..57d21a0 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1854,7 +1854,7 @@ static void handle_bad_sector(struct bio *bio)
 	char b[BDEVNAME_SIZE];
 
 	printk(KERN_INFO "attempt to access beyond end of device\n");
-	printk(KERN_INFO "%s: rw=%d,%ld, want=%Lu, limit=%Lu\n",
+	printk(KERN_INFO "%s: rw=%d,%u, want=%Lu, limit=%Lu\n",
 			bdevname(bio->bi_bdev, b),
 			bio->bi_op, bio->bi_rw,
 			(unsigned long long)bio_end_sector(bio),
diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index b7341de..29b99fb 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -266,7 +266,7 @@ static void corrupt_bio_data(struct bio *bio, struct flakey_c *fc)
 		data[fc->corrupt_bio_byte - 1] = fc->corrupt_bio_value;
 
 		DMDEBUG("Corrupting data bio=%p by writing %u to byte %u "
-			"(rw=%c bi_rw=%lu bi_sector=%llu cur_bytes=%u)\n",
+			"(rw=%c bi_rw=%u bi_sector=%llu cur_bytes=%u)\n",
 			bio, fc->corrupt_bio_value, fc->corrupt_bio_byte,
 			(bio_data_dir(bio) == WRITE) ? 'w' : 'r', bio->bi_rw,
 			(unsigned long long)bio->bi_iter.bi_sector, bio_bytes);
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index c36b817..7fb693f 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -1006,9 +1006,9 @@ again:
 				: raid5_end_read_request;
 			bi->bi_private = sh;
 
-			pr_debug("%s: for %llu schedule op %ld on disc %d\n",
+			pr_debug("%s: for %llu schedule op %d,%u on disc %d\n",
 				__func__, (unsigned long long)sh->sector,
-				bi->bi_rw, i);
+				bi->bi_op, bi->bi_rw, i);
 			atomic_inc(&sh->count);
 			if (sh != head_sh)
 				atomic_inc(&head_sh->count);
@@ -1058,10 +1058,10 @@ again:
 			rbi->bi_end_io = raid5_end_write_request;
 			rbi->bi_private = sh;
 
-			pr_debug("%s: for %llu schedule op %ld on "
+			pr_debug("%s: for %llu schedule op %d,%u on "
 				 "replacement disc %d\n",
 				__func__, (unsigned long long)sh->sector,
-				rbi->bi_rw, i);
+				rbi->bi_op, rbi->bi_rw, i);
 			atomic_inc(&sh->count);
 			if (sh != head_sh)
 				atomic_inc(&head_sh->count);
@@ -1093,8 +1093,9 @@ again:
 		if (!rdev && !rrdev) {
 			if (op_is_write(op))
 				set_bit(STRIPE_DEGRADED, &sh->state);
-			pr_debug("skip op %ld on disc %d for sector %llu\n",
-				bi->bi_rw, i, (unsigned long long)sh->sector);
+			pr_debug("skip op %d,%u on disc %d for sector %llu\n",
+				 bi->bi_op, bi->bi_rw, i,
+				 (unsigned long long)sh->sector);
 			clear_bit(R5_LOCKED, &sh->dev[i].flags);
 			set_bit(STRIPE_HANDLE, &sh->state);
 		}
diff --git a/fs/btrfs/check-integrity.c b/fs/btrfs/check-integrity.c
index c4a48e8..921a858 100644
--- a/fs/btrfs/check-integrity.c
+++ b/fs/btrfs/check-integrity.c
@@ -2943,7 +2943,7 @@ static void __btrfsic_submit_bio(struct bio *bio)
 		if (dev_state->state->print_mask &
 		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
 			printk(KERN_INFO
-			       "submit_bio(rw=%d,0x%lx, bi_vcnt=%u,"
+			       "submit_bio(rw=%d,0x%x, bi_vcnt=%u,"
 			       " bi_sector=%llu (bytenr %llu), bi_bdev=%p)\n",
 			       bio->bi_op, bio->bi_rw, bio->bi_vcnt,
 			       (unsigned long long)bio->bi_iter.bi_sector,
@@ -2986,7 +2986,7 @@ static void __btrfsic_submit_bio(struct bio *bio)
 		if (dev_state->state->print_mask &
 		    BTRFSIC_PRINT_MASK_SUBMIT_BIO_BH)
 			printk(KERN_INFO
-			       "submit_bio(rw=%d,0x%lx FLUSH, bdev=%p)\n",
+			       "submit_bio(rw=%d,0x%x FLUSH, bdev=%p)\n",
 			       bio->bi_op, bio->bi_rw, bio->bi_bdev);
 		if (!dev_state->dummy_block_for_bio_bh_flush.is_iodone) {
 			if ((dev_state->state->print_mask &
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index bd214ab..e2617ba 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -8153,7 +8153,7 @@ static void btrfs_end_dio_bio(struct bio *bio)
 
 	if (err)
 		btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
-			   "direct IO failed ino %llu rw %d,%lu sector %#Lx len %u err no %d",
+			   "direct IO failed ino %llu rw %d,0x%x sector %#Lx len %u err no %d",
 			   btrfs_ino(dip->inode), bio->bi_op, bio->bi_rw,
 			   (unsigned long long)bio->bi_iter.bi_sector,
 			   bio->bi_iter.bi_size, err);
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 9e7b18b..5ece950 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -44,18 +44,9 @@
 #define BIO_MAX_SIZE		(BIO_MAX_PAGES << PAGE_SHIFT)
 #define BIO_MAX_SECTORS		(BIO_MAX_SIZE >> 9)
 
-/*
- * upper 16 bits of bi_rw define the io priority of this bio
- */
-#define BIO_PRIO_SHIFT	(8 * sizeof(unsigned long) - IOPRIO_BITS)
-#define bio_prio(bio)	((bio)->bi_rw >> BIO_PRIO_SHIFT)
+#define bio_prio(bio)		(bio)->bi_ioprio
 #define bio_prio_valid(bio)	ioprio_valid(bio_prio(bio))
-
-#define bio_set_prio(bio, prio)		do {			\
-	WARN_ON(prio >= (1 << IOPRIO_BITS));			\
-	(bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);		\
-	(bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);	\
-} while (0)
+#define bio_set_prio(bio, prio)	((bio)->bi_ioprio = prio)
 
 /*
  * various member access, note that bio_data should of course not be used
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index b4251ed..498f395 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -48,14 +48,9 @@ struct bio {
 	struct block_device	*bi_bdev;
 	unsigned int		bi_flags;	/* status, command, etc */
 	int			bi_error;
-	unsigned long		bi_rw;		/* bottom bits rq_flags_bits
-						 * top bits priority
-						 */
-	/*
-	 * this will be a u8 in the next patches and bi_rw can be shrunk to
-	 * a u32. For compat in these transistional patches op is a int here.
-	 */
-	int			bi_op;		/* REQ_OP */
+	unsigned int		bi_rw;		/* rq_flag_bits */
+	unsigned short		bi_ioprio;
+	u8			bi_op;		/* REQ_OP */
 
 
 	struct bvec_iter	bi_iter;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 5694894..b483a66 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -96,7 +96,7 @@ struct request {
 	struct request_queue *q;
 	struct blk_mq_ctx *mq_ctx;
 
-	int op;
+	u8 op;
 	u64 cmd_flags;
 	unsigned cmd_type;
 	unsigned long atomic_flags;
-- 
2.7.2