On Mon, Nov 20, 2023 at 05:38:46PM +0800, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@xxxxxxxxxx>
>
> There are multiple switches in struct block_device, use seperate bool
> fields for them is not gracefully. Add a new field flags and replace
> swithes to a bit, there are no functional changes, and preapre to add
> a new switch in the next patch.
>
> Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
> ---
> block/bdev.c | 15 ++++++++-------
> block/blk-core.c | 7 ++++---
> block/genhd.c | 8 +++++---
> block/ioctl.c | 2 +-
> include/linux/blk_types.h | 12 ++++++------
> include/linux/blkdev.h | 5 +++--
> 6 files changed, 27 insertions(+), 22 deletions(-)
>
> diff --git a/block/bdev.c b/block/bdev.c
> index fc8d28d77495..cb849bcf61ae 100644
> --- a/block/bdev.c
> +++ b/block/bdev.c
> @@ -408,10 +408,10 @@ struct block_device *bdev_alloc(struct gendisk *disk, u8 partno)
> bdev->bd_partno = partno;
> bdev->bd_inode = inode;
> bdev->bd_queue = disk->queue;
> - if (partno)
> - bdev->bd_has_submit_bio = disk->part0->bd_has_submit_bio;
> + if (partno && test_bit(BD_FLAG_HAS_SUBMIT_BIO, &disk->part0->flags))
> + set_bit(BD_FLAG_HAS_SUBMIT_BIO, &bdev->flags);
> else
> - bdev->bd_has_submit_bio = false;
> + clear_bit(BD_FLAG_HAS_SUBMIT_BIO, &bdev->flags);
> bdev->bd_stats = alloc_percpu(struct disk_stats);
> if (!bdev->bd_stats) {
> iput(inode);
> @@ -612,7 +612,7 @@ static void bd_end_claim(struct block_device *bdev, void *holder)
> bdev->bd_holder = NULL;
> bdev->bd_holder_ops = NULL;
> mutex_unlock(&bdev->bd_holder_lock);
> - if (bdev->bd_write_holder)
> + if (test_bit(BD_FLAG_WRITE_HOLDER, &bdev->flags))
> unblock = true;
> }
> if (!whole->bd_holders)
> @@ -625,7 +625,7 @@ static void bd_end_claim(struct block_device *bdev, void *holder)
> */
> if (unblock) {
> disk_unblock_events(bdev->bd_disk);
> - bdev->bd_write_holder = false;
> + clear_bit(BD_FLAG_WRITE_HOLDER, &bdev->flags);
> }
> }
>
> @@ -878,9 +878,10 @@ struct bdev_handle *bdev_open_by_dev(dev_t dev, blk_mode_t mode, void *holder,
> * writeable reference is too fragile given the way @mode is
> * used in blkdev_get/put().
> */
> - if ((mode & BLK_OPEN_WRITE) && !bdev->bd_write_holder &&
> + if ((mode & BLK_OPEN_WRITE) &&
> + !test_bit(BD_FLAG_WRITE_HOLDER, &bdev->flags) &&
> (disk->event_flags & DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE)) {
> - bdev->bd_write_holder = true;
> + set_bit(BD_FLAG_WRITE_HOLDER, &bdev->flags);
> unblock_events = false;
> }
> }
> diff --git a/block/blk-core.c b/block/blk-core.c
> index fdf25b8d6e78..577a693165d8 100644
> --- a/block/blk-core.c
> +++ b/block/blk-core.c
> @@ -482,7 +482,8 @@ __setup("fail_make_request=", setup_fail_make_request);
>
> bool should_fail_request(struct block_device *part, unsigned int bytes)
> {
> - return part->bd_make_it_fail && should_fail(&fail_make_request, bytes);
> + return test_bit(BD_FLAG_MAKE_IT_FAIL, &part->flags) &&
> + should_fail(&fail_make_request, bytes);
> }
>
> static int __init fail_make_request_debugfs(void)
> @@ -595,7 +596,7 @@ static void __submit_bio(struct bio *bio)
> if (unlikely(!blk_crypto_bio_prep(&bio)))
> return;
>
> - if (!bio->bi_bdev->bd_has_submit_bio) {
> + if (!test_bit(BD_FLAG_HAS_SUBMIT_BIO, &bio->bi_bdev->flags)) {
> blk_mq_submit_bio(bio);
> } else if (likely(bio_queue_enter(bio) == 0)) {
> struct gendisk *disk = bio->bi_bdev->bd_disk;
> @@ -703,7 +704,7 @@ void submit_bio_noacct_nocheck(struct bio *bio)
> */
> if (current->bio_list)
> bio_list_add(¤t->bio_list[0], bio);
> - else if (!bio->bi_bdev->bd_has_submit_bio)
> + else if (!test_bit(BD_FLAG_HAS_SUBMIT_BIO, &bio->bi_bdev->flags))
> __submit_bio_noacct_mq(bio);
> else
> __submit_bio_noacct(bio);
> diff --git a/block/genhd.c b/block/genhd.c
> index c9d06f72c587..026f4c6d5b7e 100644
> --- a/block/genhd.c
> +++ b/block/genhd.c
> @@ -413,7 +413,8 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
> elevator_init_mq(disk->queue);
>
> /* Mark bdev as having a submit_bio, if needed */
> - disk->part0->bd_has_submit_bio = disk->fops->submit_bio != NULL;
> + if (disk->fops->submit_bio)
> + set_bit(BD_FLAG_HAS_SUBMIT_BIO, &disk->part0->flags);
>
> /*
> * If the driver provides an explicit major number it also must provide
> @@ -1062,7 +1063,8 @@ static DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL);
> ssize_t part_fail_show(struct device *dev,
> struct device_attribute *attr, char *buf)
> {
> - return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
> + return sprintf(buf, "%d\n",
> + test_bit(BD_FLAG_MAKE_IT_FAIL, &dev_to_bdev(dev)->flags));
> }
>
> ssize_t part_fail_store(struct device *dev,
> @@ -1072,7 +1074,7 @@ ssize_t part_fail_store(struct device *dev,
> int i;
>
> if (count > 0 && sscanf(buf, "%d", &i) > 0)
> - dev_to_bdev(dev)->bd_make_it_fail = i;
> + set_bit(BD_FLAG_MAKE_IT_FAIL, &dev_to_bdev(dev)->flags);
>
> return count;
> }
> diff --git a/block/ioctl.c b/block/ioctl.c
> index 4160f4e6bd5b..a548c718a5fb 100644
> --- a/block/ioctl.c
> +++ b/block/ioctl.c
> @@ -394,7 +394,7 @@ static int blkdev_roset(struct block_device *bdev, unsigned cmd,
> if (ret)
> return ret;
> }
> - bdev->bd_read_only = n;
> + set_bit(BD_FLAG_READ_ONLY, &bdev->flags);
> return 0;
> }
>
> diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
> index 52e264d5a830..95bd26c62655 100644
> --- a/include/linux/blk_types.h
> +++ b/include/linux/blk_types.h
> @@ -37,17 +37,20 @@ struct bio_crypt_ctx;
> #define PAGE_SECTORS (1 << PAGE_SECTORS_SHIFT)
> #define SECTOR_MASK (PAGE_SECTORS - 1)
>
> +#define BD_FLAG_READ_ONLY 0 /* read-only-policy */
> +#define BD_FLAG_WRITE_HOLDER 1
> +#define BD_FLAG_HAS_SUBMIT_BIO 2
> +#define BD_FLAG_MAKE_IT_FAIL 3
> +
> struct block_device {
> sector_t bd_start_sect;
> sector_t bd_nr_sectors;
> struct gendisk * bd_disk;
> struct request_queue * bd_queue;
> struct disk_stats __percpu *bd_stats;
> + unsigned long flags;
> unsigned long bd_stamp;
> - bool bd_read_only; /* read-only policy */
> u8 bd_partno;
> - bool bd_write_holder;
> - bool bd_has_submit_bio;
The idea looks good, but not necessary to add new 8 bytes, and you may
put all these flags and `bd_partno` into single 'unsigned long', and add
helpers to retrieve part no, since there are not many ->bd_partno
references.
Thanks,
Ming
