| Message ID | 20221005050027.39591-2-kch@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | block: add and use init disk helper | expand |
On Tue, Oct 04, 2022 at 10:00:10PM -0700, Chaitanya Kulkarni wrote: > +void init_disk(struct gendisk *disk, int major, int first_minor, > + int minors, sector_t sectors, void *private_data, > + const struct block_device_operations *fops) > +{ > + disk->major = major; > + disk->first_minor = first_minor; > + disk->minors = minors; > + set_capacity(disk, sectors); > + disk->private_data = private_data; > + disk->fops = fops; I don't like this at all. For one major/first_minor/minors are optional and discouraged for new drivers. Setting the capacity is a different thing and is done by helpers also used for revalidation in many drivers. It might make sense to pass the fops (and maybe private_data) to blk_mq_alloc_disk / blk_alloc_disk, but even then I'm not quite sure it is worth the churn.
On 10/10/22 00:59, Christoph Hellwig wrote: > On Tue, Oct 04, 2022 at 10:00:10PM -0700, Chaitanya Kulkarni wrote: >> +void init_disk(struct gendisk *disk, int major, int first_minor, >> + int minors, sector_t sectors, void *private_data, >> + const struct block_device_operations *fops) >> +{ >> + disk->major = major; >> + disk->first_minor = first_minor; >> + disk->minors = minors; >> + set_capacity(disk, sectors); >> + disk->private_data = private_data; >> + disk->fops = fops; > > I don't like this at all. For one major/first_minor/minors are > optional and discouraged for new drivers. Setting the capacity is > a different thing and is done by helpers also used for revalidation > in many drivers. > > It might make sense to pass the fops (and maybe private_data) to > blk_mq_alloc_disk / blk_alloc_disk, but even then I'm not quite > sure it is worth the churn. Okay I'll drop this, and see if I can get something meaningful with fops and private data. -ck
diff --git a/block/genhd.c b/block/genhd.c index 514395361d7c..701309a7388e 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1470,3 +1470,16 @@ void inc_diskseq(struct gendisk *disk) { disk->diskseq = atomic64_inc_return(&diskseq); } + +void init_disk(struct gendisk *disk, int major, int first_minor, + int minors, sector_t sectors, void *private_data, + const struct block_device_operations *fops) +{ + disk->major = major; + disk->first_minor = first_minor; + disk->minors = minors; + set_capacity(disk, sectors); + disk->private_data = private_data; + disk->fops = fops; +} +EXPORT_SYMBOL_GPL(init_disk); diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c index 1f154f92f4c2..d31085c94fd3 100644 --- a/drivers/block/null_blk/main.c +++ b/drivers/block/null_blk/main.c @@ -1871,18 +1871,14 @@ static int init_driver_queues(struct nullb *nullb) static int null_gendisk_register(struct nullb *nullb) { sector_t size = ((sector_t)nullb->dev->size * SZ_1M) >> SECTOR_SHIFT; + const struct block_device_operations *fops; struct gendisk *disk = nullb->disk; - set_capacity(disk, size); - - disk->major = null_major; - disk->first_minor = nullb->index; - disk->minors = 1; if (queue_is_mq(nullb->q)) - disk->fops = &null_rq_ops; + fops = &null_rq_ops; else - disk->fops = &null_bio_ops; - disk->private_data = nullb; + fops = &null_bio_ops; + init_disk(disk, null_major, nullb->index, 1, size, nullb, fops); strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN); if (nullb->dev->zoned) { diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 49373d002631..cb9db857f890 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -757,6 +757,11 @@ static inline int __must_check add_disk(struct gendisk *disk) { return device_add_disk(NULL, disk, NULL); } + +void init_disk(struct gendisk *disk, int major, int first_minor, + int minors, sector_t sectors, void *private_data, + const struct block_device_operations *fops); + void del_gendisk(struct gendisk *gp); void invalidate_disk(struct gendisk *disk); void set_disk_ro(struct gendisk *disk, bool read_only);
Add and use the helper to initialize the common fields of struct gendisk such as major, first_minor, minors, disk_name, private_data, and ops. This initialization is spread all over the block drivers. This avoids code repetation of inialization code of gendisk in current block drivers and any future ones. Signed-off-by: Chaitanya Kulkarni <kch@nvidia.com> --- block/genhd.c | 13 +++++++++++++ drivers/block/null_blk/main.c | 12 ++++-------- include/linux/blkdev.h | 5 +++++ 3 files changed, 22 insertions(+), 8 deletions(-)