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.
