[PATCH 13/20] block-gen: assert that bdrv_co_pwrite_{zeros/sync} is always called with graph rdlock taken

From: Emanuele Giuseppe Esposito <eesposit@redhat.com>
To: qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>, Hanna Reitz <hreitz@redhat.com>,
	John Snow <jsnow@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>,
	Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>,
	Stefan Hajnoczi <stefanha@redhat.com>, Fam Zheng <fam@euphon.net>,
	Eric Blake <eblake@redhat.com>, Cleber Rosa <crosa@redhat.com>,
	qemu-devel@nongnu.org,
	Emanuele Giuseppe Esposito <eesposit@redhat.com>
Subject: [PATCH 13/20] block-gen: assert that bdrv_co_pwrite_{zeros/sync} is always called with graph rdlock taken
Date: Wed, 16 Nov 2022 08:48:43 -0500	[thread overview]
Message-ID: <20221116134850.3051419-14-eesposit@redhat.com> (raw)
In-Reply-To: <20221116134850.3051419-1-eesposit@redhat.com>

Already protected by bdrv_co_pwrite callers.

Protecting bdrv_co_do_pwrite_zeroes() implies that
BlockDriver->bdrv_co_pwrite_zeroes() is always called with
graph rdlock taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
---
 block/io.c                       | 3 +++
 include/block/block_int-common.h | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/block/io.c b/block/io.c
index 9280fb9f38..92c74648fb 100644
--- a/block/io.c
+++ b/block/io.c
@@ -904,6 +904,7 @@ int coroutine_fn bdrv_co_pwrite_sync(BdrvChild *child, int64_t offset,
 {
     int ret;
     IO_CODE();
+    assert_bdrv_graph_readable();
 
     ret = bdrv_co_pwrite(child, offset, bytes, buf, flags);
     if (ret < 0) {
@@ -1660,6 +1661,7 @@ static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
                         bs->bl.request_alignment);
     int max_transfer = MIN_NON_ZERO(bs->bl.max_transfer, MAX_BOUNCE_BUFFER);
 
+    assert_bdrv_graph_readable();
     bdrv_check_request(offset, bytes, &error_abort);
 
     if (!drv) {
@@ -2124,6 +2126,7 @@ int coroutine_fn bdrv_co_pwrite_zeroes(BdrvChild *child, int64_t offset,
 {
     IO_CODE();
     trace_bdrv_co_pwrite_zeroes(child->bs, offset, bytes, flags);
+    assert_bdrv_graph_readable();
 
     if (!(child->bs->open_flags & BDRV_O_UNMAP)) {
         flags &= ~BDRV_REQ_MAY_UNMAP;
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index d44f825d95..e8d2e4b6c7 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -549,6 +549,8 @@ struct BlockDriver {
      * would use a compact metadata representation to implement this.  This
      * function pointer may be NULL or return -ENOSUP and .bdrv_co_writev()
      * will be called instead.
+     *
+     * Called with graph rdlock taken.
      */
     int coroutine_fn (*bdrv_co_pwrite_zeroes)(BlockDriverState *bs,
         int64_t offset, int64_t bytes, BdrvRequestFlags flags);
-- 
2.31.1


