[Qemu-block] [PATCH v2 04/19] block: Convert bdrv_aio_discard() to byte-based

[Eric Blake]

Another step towards byte-based interfaces everywhere.  Replace
the sector-based bdrv_aio_discard() with a new byte-based
bdrv_aio_pdiscard(), which silently ignores any unaligned head
or tail.  Driver callbacks will be converted in followup patches.

Signed-off-by: Eric Blake <address@hidden>

---
v2: rebase to master and to qiov change in previous patch
---
 include/block/block.h |  6 +++---
 block/block-backend.c |  3 ++-
 block/io.c            | 15 +++++++--------
 block/trace-events    |  2 +-
 4 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/include/block/block.h b/include/block/block.h
index 94cabbb..11c162d 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -316,9 +316,9 @@ BlockAIOCB *bdrv_aio_writev(BdrvChild *child, int64_t 
sector_num,
                             BlockCompletionFunc *cb, void *opaque);
 BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
                            BlockCompletionFunc *cb, void *opaque);
-BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
-                             int64_t sector_num, int nb_sectors,
-                             BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *bdrv_aio_pdiscard(BlockDriverState *bs,
+                              int64_t offset, int count,
+                              BlockCompletionFunc *cb, void *opaque);
 void bdrv_aio_cancel(BlockAIOCB *acb);
 void bdrv_aio_cancel_async(BlockAIOCB *acb);

diff --git a/block/block-backend.c b/block/block-backend.c
index 83b6407..8b16b95 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -1074,7 +1074,8 @@ BlockAIOCB *blk_aio_discard(BlockBackend *blk,
         return blk_abort_aio_request(blk, cb, opaque, ret);
     }

-    return bdrv_aio_discard(blk_bs(blk), sector_num, nb_sectors, cb, opaque);
+    return bdrv_aio_pdiscard(blk_bs(blk), sector_num << BDRV_SECTOR_BITS,
+                             nb_sectors << BDRV_SECTOR_BITS, cb, opaque);
 }

 void blk_aio_cancel(BlockAIOCB *acb)
diff --git a/block/io.c b/block/io.c
index 478aade..3babbdc 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2192,7 +2192,7 @@ BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
     return &acb->common;
 }

-static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
+static void coroutine_fn bdrv_aio_pdiscard_co_entry(void *opaque)
 {
     BlockAIOCBCoroutine *acb = opaque;
     BlockDriverState *bs = acb->common.bs;
@@ -2201,21 +2201,20 @@ static void coroutine_fn bdrv_aio_discard_co_entry(void 
*opaque)
     bdrv_co_complete(acb);
 }

-BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
-        int64_t sector_num, int nb_sectors,
-        BlockCompletionFunc *cb, void *opaque)
+BlockAIOCB *bdrv_aio_pdiscard(BlockDriverState *bs, int64_t offset, int count,
+                              BlockCompletionFunc *cb, void *opaque)
 {
     Coroutine *co;
     BlockAIOCBCoroutine *acb;

-    trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque);
+    trace_bdrv_aio_pdiscard(bs, offset, count, opaque);

     acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
     acb->need_bh = true;
     acb->req.error = -EINPROGRESS;
-    acb->req.offset = sector_num << BDRV_SECTOR_BITS;
-    acb->req.bytes = nb_sectors << BDRV_SECTOR_BITS;
-    co = qemu_coroutine_create(bdrv_aio_discard_co_entry, acb);
+    acb->req.offset = offset;
+    acb->req.bytes = count;
+    co = qemu_coroutine_create(bdrv_aio_pdiscard_co_entry, acb);
     qemu_coroutine_enter(co);

     bdrv_co_maybe_schedule_bh(acb);
diff --git a/block/trace-events b/block/trace-events
index 354967e..90d618a 100644
--- a/block/trace-events
+++ b/block/trace-events
@@ -9,7 +9,7 @@ blk_co_preadv(void *blk, void *bs, int64_t offset, unsigned int 
bytes, int flags
 blk_co_pwritev(void *blk, void *bs, int64_t offset, unsigned int bytes, int 
flags) "blk %p bs %p offset %"PRId64" bytes %u flags %x"

 # block/io.c
-bdrv_aio_discard(void *bs, int64_t sector_num, int nb_sectors, void *opaque) 
"bs %p sector_num %"PRId64" nb_sectors %d opaque %p"
+bdrv_aio_pdiscard(void *bs, int64_t offset, int count, void *opaque) "bs %p 
offset %"PRId64" count %d opaque %p"
 bdrv_aio_flush(void *bs, void *opaque) "bs %p opaque %p"
 bdrv_aio_readv(void *bs, int64_t sector_num, int nb_sectors, void *opaque) "bs 
%p sector_num %"PRId64" nb_sectors %d opaque %p"
 bdrv_aio_writev(void *bs, int64_t sector_num, int nb_sectors, void *opaque) 
"bs %p sector_num %"PRId64" nb_sectors %d opaque %p"
-- 
2.5.5