dm bufio: Support IO priority

Some IO will dispatch from kworker with different io_context settings
than the submitting task, we may need to specify a priority to avoid
losing priority.

Add dm_bufio_read_with_ioprio() and dm_bufio_prefetch_with_ioprio()
for use by bufio users to pass an ioprio other than IOPRIO_DEFAULT.

Co-developed-by: Yibin Ding <yibin.ding@unisoc.com>
Signed-off-by: Yibin Ding <yibin.ding@unisoc.com>
Signed-off-by: Hongyu Jin <hongyu.jin@unisoc.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
[snitzer: introduced _with_ioprio() wrappers to reduce churn]
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/dm-bufio.h b/include/linux/dm-bufio.h
index 75e7d8cbb532..d1503b815a78 100644
--- a/include/linux/dm-bufio.h
+++ b/include/linux/dm-bufio.h
@@ -64,6 +64,9 @@ void dm_bufio_set_sector_offset(struct dm_bufio_client *c, sector_t start);
 void *dm_bufio_read(struct dm_bufio_client *c, sector_t block,
 		    struct dm_buffer **bp);
 
+void *dm_bufio_read_with_ioprio(struct dm_bufio_client *c, sector_t block,
+				struct dm_buffer **bp, unsigned short ioprio);
+
 /*
  * Like dm_bufio_read, but return buffer from cache, don't read
  * it. If the buffer is not in the cache, return NULL.
@@ -86,6 +89,10 @@ void *dm_bufio_new(struct dm_bufio_client *c, sector_t block,
 void dm_bufio_prefetch(struct dm_bufio_client *c,
 		       sector_t block, unsigned int n_blocks);
 
+void dm_bufio_prefetch_with_ioprio(struct dm_bufio_client *c,
+				sector_t block, unsigned int n_blocks,
+				unsigned short ioprio);
+
 /*
  * Release a reference obtained with dm_bufio_{read,get,new}. The data
  * pointer and dm_buffer pointer is no longer valid after this call.