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

From: mchristi
Date: Fri Apr 15 2016 - 15:20:02 EST


From: Mike Christie <mchristi@xxxxxxxxxx>

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@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
---
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