block: Implement bdrv_{pread,pwrite,pwrite_zeroes}() using generated_…

…co_wrapper

bdrv_{pread,pwrite}() now return -EIO instead of -EINVAL when 'bytes' is
negative, making them consistent with bdrv_{preadv,pwritev}() and
bdrv_co_{pread,pwrite,preadv,pwritev}().

bdrv_pwrite_zeroes() now also calls trace_bdrv_co_pwrite_zeroes() and
clears the BDRV_REQ_MAY_UNMAP flag when appropriate, which it didn't
previously.

Signed-off-by: Alberto Faria <afaria@redhat.com>
Message-Id: <20220609152744.3891847-8-afaria@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>

block/io.c

@@ -1046,14 +1046,6 @@ static int bdrv_check_request32(int64_t offset, int64_t bytes,
     return 0;
 }
 
-int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
-                       int64_t bytes, BdrvRequestFlags flags)
-{
-    IO_CODE();
-    return bdrv_pwritev(child, offset, bytes, NULL,
-                        BDRV_REQ_ZERO_WRITE | flags);
-}
-
 /*
  * Completely zero out a block device with the help of bdrv_pwrite_zeroes.
  * The operation is sped up by checking the block status and only writing
@@ -1096,39 +1088,6 @@ int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags)
     }
 }
 
-/* See bdrv_pwrite() for the return codes */
-int bdrv_pread(BdrvChild *child, int64_t offset, int64_t bytes, void *buf,
-               BdrvRequestFlags flags)
-{
-    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
-    IO_CODE();
-
-    if (bytes < 0) {
-        return -EINVAL;
-    }
-
-    return bdrv_preadv(child, offset, bytes, &qiov, flags);
-}
-
-/* Return no. of bytes on success or < 0 on error. Important errors are:
-  -EIO         generic I/O error (may happen for all errors)
-  -ENOMEDIUM   No media inserted.
-  -EINVAL      Invalid offset or number of bytes
-  -EACCES      Trying to write a read-only device
-*/
-int bdrv_pwrite(BdrvChild *child, int64_t offset, int64_t bytes,
-                const void *buf, BdrvRequestFlags flags)
-{
-    QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
-    IO_CODE();
-
-    if (bytes < 0) {
-        return -EINVAL;
-    }
-
-    return bdrv_pwritev(child, offset, bytes, &qiov, flags);
-}
-
 /*
  * Writes to the file and ensures that no writes are reordered across this
  * request (acts as a barrier)

include/block/block-io.h

@@ -39,13 +39,16 @@
  * to catch when they are accidentally called by the wrong API.
  */
 
-int bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
-                       int64_t bytes, BdrvRequestFlags flags);
+int generated_co_wrapper bdrv_pwrite_zeroes(BdrvChild *child, int64_t offset,
+                                            int64_t bytes,
+                                            BdrvRequestFlags flags);
 int bdrv_make_zero(BdrvChild *child, BdrvRequestFlags flags);
-int bdrv_pread(BdrvChild *child, int64_t offset, int64_t bytes, void *buf,
-               BdrvRequestFlags flags);
-int bdrv_pwrite(BdrvChild *child, int64_t offset, int64_t bytes,
-                const void *buf, BdrvRequestFlags flags);
+int generated_co_wrapper bdrv_pread(BdrvChild *child, int64_t offset,
+                                    int64_t bytes, void *buf,
+                                    BdrvRequestFlags flags);
+int generated_co_wrapper bdrv_pwrite(BdrvChild *child, int64_t offset,
+                                     int64_t bytes, const void *buf,
+                                     BdrvRequestFlags flags);
 int bdrv_pwrite_sync(BdrvChild *child, int64_t offset, int64_t bytes,
                      const void *buf, BdrvRequestFlags flags);
 /*