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From f1f339c365d7e68790ba8f84d0e16daac462d627 Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Tue, 3 Dec 2013 14:40:18 +0100
Subject: [PATCH 15/37] block: Introduce bdrv_co_do_pwritev()

Message-id: <1392117622-28812-16-git-send-email-kwolf@redhat.com>
Patchwork-id: 57180
O-Subject: [RHEL-7.0 qemu-kvm PATCH v2 15/37] block: Introduce bdrv_co_do_pwritev()
Bugzilla: 748906
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
RH-Acked-by: Max Reitz <mreitz@redhat.com>

This is going to become the bdrv_co_do_preadv() equivalent for writes.
In this patch, however, just a function taking byte offsets is created,
it doesn't align anything yet.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
(cherry picked from commit 6601553e27091ffe240bea69227adce941fe12e8)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)
---
 block.c |   24 ++++++++++++++++++------
 1 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/block.c b/block.c
index d8168f5..7b8131c 100644
--- a/block.c
+++ b/block.c
@@ -3032,8 +3032,8 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
 /*
  * Handle a write request in coroutine context
  */
-static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
-    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+static int coroutine_fn bdrv_co_do_pwritev(BlockDriverState *bs,
+    int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
     BdrvRequestFlags flags)
 {
     int ret;
@@ -3044,21 +3044,33 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
     if (bs->read_only) {
         return -EACCES;
     }
-    if (bdrv_check_request(bs, sector_num, nb_sectors)) {
+    if (bdrv_check_byte_request(bs, offset, bytes)) {
         return -EIO;
     }
 
     /* throttling disk I/O */
     if (bs->io_limits_enabled) {
-        bdrv_io_limits_intercept(bs, true, nb_sectors);
+        /* TODO Switch to byte granularity */
+        bdrv_io_limits_intercept(bs, true, bytes >> BDRV_SECTOR_BITS);
     }
 
-    ret = bdrv_aligned_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
-                               nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
+    ret = bdrv_aligned_pwritev(bs, offset, bytes, qiov, flags);
 
     return ret;
 }
 
+static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
+    int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
+    BdrvRequestFlags flags)
+{
+    if (nb_sectors < 0 || nb_sectors > (INT_MAX >> BDRV_SECTOR_BITS)) {
+        return -EINVAL;
+    }
+
+    return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
+                              nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
+}
+
 int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
     int nb_sectors, QEMUIOVector *qiov)
 {
-- 
1.7.1