On 2/1/22 10:32, Mikulas Patocka wrote:
/** + * blk_queue_max_copy_sectors - set maximum copy offload sectors for the queue + * @q: the request queue for the device + * @size: the maximum copy offload sectors + */ +void blk_queue_max_copy_sectors(struct request_queue *q, unsigned int size) +{ + q->limits.max_copy_sectors = size; +} +EXPORT_SYMBOL_GPL(blk_queue_max_copy_sectors);
Please either change the unit of 'size' into bytes or change its type into sector_t.
+extern int blkdev_issue_copy(struct block_device *bdev1, sector_t sector1, + struct block_device *bdev2, sector_t sector2, + sector_t nr_sects, sector_t *copied, gfp_t gfp_mask); +
Only supporting copying between contiguous LBA ranges seems restrictive to me. I expect garbage collection by filesystems for UFS devices to perform better if multiple LBA ranges are submitted as a single SCSI XCOPY command.
A general comment about the approach: encoding the LBA range information in a bio payload is not compatible with bio splitting. How can the dm driver implement copy offloading without the ability to split copy offload bio's?
+int blkdev_issue_copy(struct block_device *bdev1, sector_t sector1, + struct block_device *bdev2, sector_t sector2, + sector_t nr_sects, sector_t *copied, gfp_t gfp_mask) +{ + struct page *token; + sector_t m; + int r = 0; + struct completion comp;
Consider using DECLARE_COMPLETION_ONSTACK() instead of a separate declaration and init_completion() call.
Thanks, Bart. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel