On 5/21/25 3:31 PM, Keith Busch wrote:
+/**
+ * blkdev_copy - copy source sectors to a destination on the same block device
+ * @dst_sector: start sector of the destination to copy to
+ * @src_sector: start sector of the source to copy from
+ * @nr_sects: number of sectors to copy
+ * @gfp: allocation flags to use
+ */
+int blkdev_copy(struct block_device *bdev, sector_t dst_sector,
+ sector_t src_sector, sector_t nr_sects, gfp_t gfp)
+{
+ unsigned int nr_vecs = __blkdev_sectors_to_bio_pages(nr_sects);
+ unsigned int len = (unsigned int)nr_sects << SECTOR_SHIFT;
+ unsigned int size = min(len, nr_vecs * PAGE_SIZE);
+ struct bio *bio;
+ int ret = 0;
+ void *buf;
+
+ if (nr_sects > UINT_MAX >> SECTOR_SHIFT)
+ return -EINVAL;
+
+ buf = kvmalloc(size, gfp);
+ if (!buf)
+ return -ENOMEM;
+
+ nr_vecs = bio_add_max_vecs(buf, size);
+ bio = bio_alloc(bdev, nr_vecs, 0, gfp);
+
+ if (is_vmalloc_addr(buf))
+ bio_add_vmalloc(bio, buf, size);
+ else
+ bio_add_virt_nofail(bio, buf, size);
+
+ while (len) {
+ size = min(len, size);
+
+ bio_reset(bio, bdev, REQ_OP_READ);
+ bio->bi_iter.bi_sector = src_sector;
+ bio->bi_iter.bi_size = size;
+
+ ret = submit_bio_wait(bio);
+ if (ret)
+ break;
+
+ bio_reset(bio, bdev, REQ_OP_WRITE);
+ bio->bi_iter.bi_sector = dst_sector;
+ bio->bi_iter.bi_size = size;
+
+ ret = submit_bio_wait(bio);
+ if (ret)
+ break;
+
+ src_sector += size >> SECTOR_SHIFT;
+ dst_sector += size >> SECTOR_SHIFT;
+ len -= size;
+ }
+
+ bio_put(bio);
+ kvfree(buf);
+ return ret;
+}
Is avoiding code duplication still a goal in the Linux kernel project?
If so, should the above code be consolidated with kcopyd into a single
implementation?
Thanks,
Bart.
