diff mbox series

[v6,01/15] block: simplify comment to BDRV_REQ_SERIALISING

Message ID 20200918181951.21752-2-vsementsov@virtuozzo.com
State New
Headers show
Series preallocate filter | expand

Commit Message

Vladimir Sementsov-Ogievskiy Sept. 18, 2020, 6:19 p.m. UTC 
1. BDRV_REQ_NO_SERIALISING doesn't exist already, don't mention it.

2. We are going to add one more user of BDRV_REQ_SERIALISING, so
   comment about backup becomes a bit confusing here. The use case in
   backup is documented in block/backup.c, so let's just drop
   duplication here.

3. The fact that BDRV_REQ_SERIALISING is only for write requests is
   omitted. Add a note.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/block/block.h | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

Comments

Alberto Garcia Sept. 28, 2020, 3:34 p.m. UTC | #1 
On Fri 18 Sep 2020 08:19:37 PM CEST, Vladimir Sementsov-Ogievskiy wrote:
> 1. BDRV_REQ_NO_SERIALISING doesn't exist already, don't mention it.
>
> 2. We are going to add one more user of BDRV_REQ_SERIALISING, so
>    comment about backup becomes a bit confusing here. The use case in
>    backup is documented in block/backup.c, so let's just drop
>    duplication here.
>
> 3. The fact that BDRV_REQ_SERIALISING is only for write requests is
>    omitted. Add a note.
>
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: Alberto Garcia <berto@igalia.com>

Berto
diff mbox series

Patch

diff --git a/include/block/block.h b/include/block/block.h
index 981ab5b314..ef948e3f34 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -53,16 +53,7 @@  typedef enum {
      * content. */
     BDRV_REQ_WRITE_UNCHANGED    = 0x40,
 
-    /*
-     * BDRV_REQ_SERIALISING forces request serialisation for writes.
-     * It is used to ensure that writes to the backing file of a backup process
-     * target cannot race with a read of the backup target that defers to the
-     * backing file.
-     *
-     * Note, that BDRV_REQ_SERIALISING is _not_ opposite in meaning to
-     * BDRV_REQ_NO_SERIALISING. A more descriptive name for the latter might be
-     * _DO_NOT_WAIT_FOR_SERIALISING, except that is too long.
-     */
+    /* Forces request serialisation. Use only with write requests. */
     BDRV_REQ_SERIALISING        = 0x80,
 
     /* Execute the request only if the operation can be offloaded or otherwise