Implement intermediate find_hole() on device-mapper layer. Do some simple checks, add new function to target_type, so any dm devices may realize it
https://jira.vzint.dev/browse/PSBM-145746 Signed-off-by: Andrey Zhadchenko <andrey.zhadche...@virtuozzo.com> --- drivers/md/dm.c | 39 +++++++++++++++++++++++++++++++++++ include/linux/device-mapper.h | 4 ++++ 2 files changed, 43 insertions(+) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index c6e16ee81281..38f810ca8829 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -480,6 +480,43 @@ static int dm_blk_ioctl(struct block_device *bdev, fmode_t mode, return r; } +static loff_t dm_find_hole(struct block_device *bdev, loff_t offset, int whence) +{ + struct mapped_device *md = bdev->bd_disk->private_data; + struct dm_table *table; + struct dm_target *ti; + loff_t ret = -ENOTTY; + int srcu_idx; + + table = dm_get_live_table(md, &srcu_idx); + if (!table || !dm_table_get_size(table)) + goto out; + + /* + * For now we only support devices that have a single target. + * But probably it is not hard to break it to a few requests to a different + * targets + */ + if (table->num_targets != 1) + goto out; + + ti = dm_table_get_target(table, 0); + + if (dm_suspended_md(md)) { + ret = -EAGAIN; + goto out; + } + + if (!ti->type->find_hole) + return -EINVAL; + + ret = ti->type->find_hole(ti, offset, whence); + +out: + dm_put_live_table(md, srcu_idx); + return ret; +} + u64 dm_start_time_ns_from_clone(struct bio *bio) { return jiffies_to_nsecs(clone_to_tio(bio)->io->start_time); @@ -3374,6 +3411,7 @@ static const struct block_device_operations dm_blk_dops = { .getgeo = dm_blk_getgeo, .report_zones = dm_blk_report_zones, .pr_ops = &dm_pr_ops, + .find_hole = &dm_find_hole, .owner = THIS_MODULE }; @@ -3383,6 +3421,7 @@ static const struct block_device_operations dm_rq_blk_dops = { .ioctl = dm_blk_ioctl, .getgeo = dm_blk_getgeo, .pr_ops = &dm_pr_ops, + .find_hole = &dm_find_hole, .owner = THIS_MODULE }; diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index dcb51342119a..dd9df875f146 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -152,6 +152,9 @@ typedef size_t (*dm_dax_copy_iter_fn)(struct dm_target *ti, pgoff_t pgoff, typedef int (*dm_dax_zero_page_range_fn)(struct dm_target *ti, pgoff_t pgoff, size_t nr_pages); +typedef loff_t (*dm_find_hole_fn)(struct dm_target *ti, loff_t offset, + int whence); + void dm_error(const char *message); struct dm_dev { @@ -203,6 +206,7 @@ struct target_type { dm_dax_copy_iter_fn dax_copy_from_iter; dm_dax_copy_iter_fn dax_copy_to_iter; dm_dax_zero_page_range_fn dax_zero_page_range; + dm_find_hole_fn find_hole; /* For internal device-mapper use. */ struct list_head list; -- 2.39.3 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel
