[PATCH 13/14] block: Convert bdrv_debug_event to co_wrapper_mixed

[Kevin Wolf <kwolf@redhat.com>]

From: Emanuele Giuseppe Esposito <eesposit@redhat.com>

bdrv_debug_event() is categorized as an I/O function, and it currently
doesn't run in a coroutine. We should let it take a graph rdlock since
it traverses the block nodes graph, which however is only possible in a
coroutine.

Therefore turn it into a co_wrapper_mixed to move the actual function
into a coroutine where the lock can be taken.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block-io.h         |  5 ++++-
 include/block/block_int-common.h |  3 ++-
 block.c                          |  2 +-
 block/io.c                       | 22 +++++++++++-----------
 4 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/include/block/block-io.h b/include/block/block-io.h
index 7e76bb647a..9737fc63cb 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -188,7 +188,10 @@ void *qemu_try_blockalign0(BlockDriverState *bs, size_t size);
 void bdrv_enable_copy_on_read(BlockDriverState *bs);
 void bdrv_disable_copy_on_read(BlockDriverState *bs);
 
-void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event);
+void coroutine_fn bdrv_co_debug_event(BlockDriverState *bs,
+                                      BlkdebugEvent event);
+void co_wrapper_mixed bdrv_debug_event(BlockDriverState *bs,
+                                       BlkdebugEvent event);
 
 #define BLKDBG_EVENT(child, evt) \
     do { \
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index 0de99682e2..90702c6dcf 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -728,7 +728,8 @@ struct BlockDriver {
     int coroutine_fn GRAPH_RDLOCK_PTR (*bdrv_co_check)(
         BlockDriverState *bs, BdrvCheckResult *result, BdrvCheckMode fix);
 
-    void (*bdrv_debug_event)(BlockDriverState *bs, BlkdebugEvent event);
+    void coroutine_fn (*bdrv_debug_event)(BlockDriverState *bs,
+                                          BlkdebugEvent event);
 
     /* io queue for linux-aio */
     void coroutine_fn (*bdrv_io_plug)(BlockDriverState *bs);
diff --git a/block.c b/block.c
index d5e660bc9d..d27105dd3b 100644
--- a/block.c
+++ b/block.c
@@ -6350,7 +6350,7 @@ BlockStatsSpecific *bdrv_get_specific_stats(BlockDriverState *bs)
     return drv->bdrv_get_specific_stats(bs);
 }
 
-void bdrv_debug_event(BlockDriverState *bs, BlkdebugEvent event)
+void coroutine_fn bdrv_co_debug_event(BlockDriverState *bs, BlkdebugEvent event)
 {
     IO_CODE();
     if (!bs || !bs->drv || !bs->drv->bdrv_debug_event) {
diff --git a/block/io.c b/block/io.c
index 116d6cf10b..93ba851c8c 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1241,7 +1241,7 @@ static int coroutine_fn bdrv_co_do_copy_on_readv(BdrvChild *child,
                 goto err;
             }
 
-            bdrv_debug_event(bs, BLKDBG_COR_WRITE);
+            bdrv_co_debug_event(bs, BLKDBG_COR_WRITE);
             if (drv->bdrv_co_pwrite_zeroes &&
                 buffer_is_zero(bounce_buffer, pnum)) {
                 /* FIXME: Should we (perhaps conditionally) be setting
@@ -1486,10 +1486,10 @@ static coroutine_fn int bdrv_padding_rmw_read(BdrvChild *child,
         qemu_iovec_init_buf(&local_qiov, pad->buf, bytes);
 
         if (pad->head) {
-            bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
+            bdrv_co_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
         }
         if (pad->merge_reads && pad->tail) {
-            bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
+            bdrv_co_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
         }
         ret = bdrv_aligned_preadv(child, req, req->overlap_offset, bytes,
                                   align, &local_qiov, 0, 0);
@@ -1497,10 +1497,10 @@ static coroutine_fn int bdrv_padding_rmw_read(BdrvChild *child,
             return ret;
         }
         if (pad->head) {
-            bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
+            bdrv_co_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
         }
         if (pad->merge_reads && pad->tail) {
-            bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
+            bdrv_co_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
         }
 
         if (pad->merge_reads) {
@@ -1511,7 +1511,7 @@ static coroutine_fn int bdrv_padding_rmw_read(BdrvChild *child,
     if (pad->tail) {
         qemu_iovec_init_buf(&local_qiov, pad->tail_buf, align);
 
-        bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
+        bdrv_co_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
         ret = bdrv_aligned_preadv(
                 child, req,
                 req->overlap_offset + req->overlap_bytes - align,
@@ -1519,7 +1519,7 @@ static coroutine_fn int bdrv_padding_rmw_read(BdrvChild *child,
         if (ret < 0) {
             return ret;
         }
-        bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
+        bdrv_co_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
     }
 
 zero_mem:
@@ -1921,16 +1921,16 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
     if (ret < 0) {
         /* Do nothing, write notifier decided to fail this request */
     } else if (flags & BDRV_REQ_ZERO_WRITE) {
-        bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO);
+        bdrv_co_debug_event(bs, BLKDBG_PWRITEV_ZERO);
         ret = bdrv_co_do_pwrite_zeroes(bs, offset, bytes, flags);
     } else if (flags & BDRV_REQ_WRITE_COMPRESSED) {
         ret = bdrv_driver_pwritev_compressed(bs, offset, bytes,
                                              qiov, qiov_offset);
     } else if (bytes <= max_transfer) {
-        bdrv_debug_event(bs, BLKDBG_PWRITEV);
+        bdrv_co_debug_event(bs, BLKDBG_PWRITEV);
         ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, qiov_offset, flags);
     } else {
-        bdrv_debug_event(bs, BLKDBG_PWRITEV);
+        bdrv_co_debug_event(bs, BLKDBG_PWRITEV);
         while (bytes_remaining) {
             int num = MIN(bytes_remaining, max_transfer);
             int local_flags = flags;
@@ -1953,7 +1953,7 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
             bytes_remaining -= num;
         }
     }
-    bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE);
+    bdrv_co_debug_event(bs, BLKDBG_PWRITEV_DONE);
 
     if (ret >= 0) {
         ret = 0;
-- 
2.38.1