[dm-devel] [PATCH 2/4] block: Simplify report zones execution
Javier González
javier at javigon.com
Fri Oct 25 05:17:48 UTC 2019
On 24.10.2019 15:50, Damien Le Moal wrote:
>All kernel users of blkdev_report_zones() as well as applications use
>through ioctl(BLKZONEREPORT) expect to potentially get less zone
>descriptors than requested. As such, the use of the internal report
>zones command execution loop implemented by blk_report_zones() is
>not necessary and can even be harmful to performance by causing the
>execution of inefficient small zones report command to service the
>reminder of a requested zone array.
>
>This patch removes blk_report_zones(), simplifying the code. Also
>remove a now incorrect comment in dm_blk_report_zones().
>
>Signed-off-by: Damien Le Moal <damien.lemoal at wdc.com>
>---
> block/blk-zoned.c | 34 +++++-----------------------------
> drivers/md/dm.c | 6 ------
> 2 files changed, 5 insertions(+), 35 deletions(-)
>
>diff --git a/block/blk-zoned.c b/block/blk-zoned.c
>index 293891b7068a..43bfd1be0985 100644
>--- a/block/blk-zoned.c
>+++ b/block/blk-zoned.c
>@@ -119,31 +119,6 @@ static bool blkdev_report_zone(struct block_device *bdev, struct blk_zone *rep)
> return true;
> }
>
>-static int blk_report_zones(struct gendisk *disk, sector_t sector,
>- struct blk_zone *zones, unsigned int *nr_zones)
>-{
>- struct request_queue *q = disk->queue;
>- unsigned int z = 0, n, nrz = *nr_zones;
>- sector_t capacity = get_capacity(disk);
>- int ret;
>-
>- while (z < nrz && sector < capacity) {
>- n = nrz - z;
>- ret = disk->fops->report_zones(disk, sector, &zones[z], &n);
>- if (ret)
>- return ret;
>- if (!n)
>- break;
>- sector += blk_queue_zone_sectors(q) * n;
>- z += n;
>- }
>-
>- WARN_ON(z > *nr_zones);
>- *nr_zones = z;
>-
>- return 0;
>-}
>-
> /**
> * blkdev_report_zones - Get zones information
> * @bdev: Target block device
>@@ -164,6 +139,7 @@ int blkdev_report_zones(struct block_device *bdev, sector_t sector,
> struct blk_zone *zones, unsigned int *nr_zones)
> {
> struct request_queue *q = bdev_get_queue(bdev);
>+ struct gendisk *disk = bdev->bd_disk;
> unsigned int i, nrz;
> int ret;
>
>@@ -175,7 +151,7 @@ int blkdev_report_zones(struct block_device *bdev, sector_t sector,
> * report_zones method. If it does not have one defined, the device
> * driver has a bug. So warn about that.
> */
>- if (WARN_ON_ONCE(!bdev->bd_disk->fops->report_zones))
>+ if (WARN_ON_ONCE(!disk->fops->report_zones))
> return -EOPNOTSUPP;
>
> if (!*nr_zones || sector >= bdev->bd_part->nr_sects) {
>@@ -185,8 +161,8 @@ int blkdev_report_zones(struct block_device *bdev, sector_t sector,
>
> nrz = min(*nr_zones,
> __blkdev_nr_zones(q, bdev->bd_part->nr_sects - sector));
>- ret = blk_report_zones(bdev->bd_disk, get_start_sect(bdev) + sector,
>- zones, &nrz);
>+ ret = disk->fops->report_zones(disk, get_start_sect(bdev) + sector,
>+ zones, &nrz);
> if (ret)
> return ret;
>
>@@ -552,7 +528,7 @@ int blk_revalidate_disk_zones(struct gendisk *disk)
>
> while (z < nr_zones) {
> nrz = min(nr_zones - z, rep_nr_zones);
>- ret = blk_report_zones(disk, sector, zones, &nrz);
>+ ret = disk->fops->report_zones(disk, sector, zones, &nrz);
> if (ret)
> goto out;
> if (!nrz)
>diff --git a/drivers/md/dm.c b/drivers/md/dm.c
>index 1a5e328c443a..647aa5b0233b 100644
>--- a/drivers/md/dm.c
>+++ b/drivers/md/dm.c
>@@ -473,12 +473,6 @@ static int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
> goto out;
> }
>
>- /*
>- * blkdev_report_zones() will loop and call this again to cover all the
>- * zones of the target, eventually moving on to the next target.
>- * So there is no need to loop here trying to fill the entire array
>- * of zones.
>- */
> ret = tgt->type->report_zones(tgt, sector, zones, nr_zones);
>
> out:
>--
>2.21.0
>
Looks good to me.
Reviewed-by: Javier González <javier at javigon.com>
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