On 23/06/28 03:50PM, Damien Le Moal wrote:
On 6/28/23 03:36, Nitesh Shetty wrote:
For the devices which does not support copy, copy emulation is added.
It is required for in-kernel users like fabrics, where file descriptor is
not available and hence they can't use copy_file_range.
Copy-emulation is implemented by reading from source into memory and
writing to the corresponding destination asynchronously.
Also emulation is used, if copy offload fails or partially completes.

Signed-off-by: Nitesh Shetty <nj.she...@samsung.com>
Signed-off-by: Vincent Fu <vincent...@samsung.com>
Signed-off-by: Anuj Gupta <anuj2...@samsung.com>
---
 block/blk-lib.c           | 183 +++++++++++++++++++++++++++++++++++++-
 block/blk-map.c           |   4 +-
 include/linux/blk_types.h |   5 ++
 include/linux/blkdev.h    |   3 +
 4 files changed, 192 insertions(+), 3 deletions(-)

diff --git a/block/blk-lib.c b/block/blk-lib.c
index 10c3eadd5bf6..09e0d5d51d03 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -234,6 +234,180 @@ static ssize_t __blkdev_copy_offload(
        return blkdev_copy_wait_io_completion(cio);
 }

+static void *blkdev_copy_alloc_buf(sector_t req_size, sector_t *alloc_size,
+               gfp_t gfp_mask)
+{
+       int min_size = PAGE_SIZE;
+       void *buf;
+
+       while (req_size >= min_size) {
+               buf = kvmalloc(req_size, gfp_mask);
+               if (buf) {
+                       *alloc_size = req_size;
+                       return buf;
+               }
+               /* retry half the requested size */

Kind of obvious :)

Acked. will remove.


+               req_size >>= 1;
+       }
+
+       return NULL;
+}
+
+static void blkdev_copy_emulate_write_endio(struct bio *bio)
+{
+       struct copy_ctx *ctx = bio->bi_private;
+       struct cio *cio = ctx->cio;
+       sector_t clen;
+
+       if (bio->bi_status) {
+               clen = (bio->bi_iter.bi_sector << SECTOR_SHIFT) - cio->pos_out;
+               cio->comp_len = min_t(sector_t, clen, cio->comp_len);
+       }
+       kfree(bvec_virt(&bio->bi_io_vec[0]));
+       bio_map_kern_endio(bio);
+       kfree(ctx);
+       if (atomic_dec_and_test(&cio->refcount)) {
+               if (cio->endio) {
+                       cio->endio(cio->private, cio->comp_len);
+                       kfree(cio);
+               } else
+                       blk_wake_io_task(cio->waiter);

Curly brackets.

acked

+       }
+}
+
+static void blkdev_copy_emulate_read_endio(struct bio *read_bio)
+{
+       struct copy_ctx *ctx = read_bio->bi_private;
+       struct cio *cio = ctx->cio;
+       sector_t clen;
+
+       if (read_bio->bi_status) {
+               clen = (read_bio->bi_iter.bi_sector << SECTOR_SHIFT) -
+                                               cio->pos_in;
+               cio->comp_len = min_t(sector_t, clen, cio->comp_len);
+               kfree(bvec_virt(&read_bio->bi_io_vec[0]));
+               bio_map_kern_endio(read_bio);
+               kfree(ctx);
+
+               if (atomic_dec_and_test(&cio->refcount)) {
+                       if (cio->endio) {
+                               cio->endio(cio->private, cio->comp_len);
+                               kfree(cio);
+                       } else
+                               blk_wake_io_task(cio->waiter);

Same.

acked


+               }
+       }
+       schedule_work(&ctx->dispatch_work);

ctx may have been freed above.

acked, will fix this.


+       kfree(read_bio);
+}
+
+static void blkdev_copy_dispatch_work(struct work_struct *work)
+{
+       struct copy_ctx *ctx = container_of(work, struct copy_ctx,
+                       dispatch_work);

Please align the argument, or even better: split the line after "=".


acked.

Thank you
Nitesh Shetty
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