[PULL 14/38] block: Convert bdrv_io_unplug() to co_wrapper

[Kevin Wolf]

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

BlockDriver->bdrv_io_unplug is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

The only caller of this function is blk_io_unplug(), therefore make
blk_io_unplug() a co_wrapper, so that we're always running in 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>
Message-Id: <20230113204212.359076-4-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/block/block-io.h          |  3 +--
 include/block/block_int-common.h  |  2 +-
 include/sysemu/block-backend-io.h |  4 +++-
 block/blkio.c                     |  4 ++--
 block/block-backend.c             |  4 ++--
 block/file-posix.c                | 10 +++++-----
 block/io.c                        |  8 ++++----
 block/nvme.c                      |  4 ++--
 8 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/include/block/block-io.h b/include/block/block-io.h
index adfc792586..322c7b61c3 100644
--- a/include/block/block-io.h
+++ b/include/block/block-io.h
@@ -213,8 +213,7 @@ void coroutine_fn bdrv_co_leave(BlockDriverState *bs, 
AioContext *old_ctx);
 AioContext *child_of_bds_get_parent_aio_context(BdrvChild *c);
 
 void coroutine_fn bdrv_co_io_plug(BlockDriverState *bs);
-
-void bdrv_io_unplug(BlockDriverState *bs);
+void coroutine_fn bdrv_co_io_unplug(BlockDriverState *bs);
 
 bool coroutine_fn bdrv_co_can_store_new_dirty_bitmap(BlockDriverState *bs,
                                                      const char *name,
diff --git a/include/block/block_int-common.h b/include/block/block_int-common.h
index a76bb76290..253df92509 100644
--- a/include/block/block_int-common.h
+++ b/include/block/block_int-common.h
@@ -730,7 +730,7 @@ struct BlockDriver {
 
     /* io queue for linux-aio */
     void coroutine_fn (*bdrv_co_io_plug)(BlockDriverState *bs);
-    void (*bdrv_io_unplug)(BlockDriverState *bs);
+    void coroutine_fn (*bdrv_co_io_unplug)(BlockDriverState *bs);
 
     /**
      * bdrv_drain_begin is called if implemented in the beginning of a
diff --git a/include/sysemu/block-backend-io.h 
b/include/sysemu/block-backend-io.h
index 70b73f7d11..d8cc8d74f5 100644
--- a/include/sysemu/block-backend-io.h
+++ b/include/sysemu/block-backend-io.h
@@ -76,7 +76,9 @@ int blk_get_max_hw_iov(BlockBackend *blk);
 void coroutine_fn blk_co_io_plug(BlockBackend *blk);
 void co_wrapper blk_io_plug(BlockBackend *blk);
 
-void blk_io_unplug(BlockBackend *blk);
+void coroutine_fn blk_co_io_unplug(BlockBackend *blk);
+void co_wrapper blk_io_unplug(BlockBackend *blk);
+
 AioContext *blk_get_aio_context(BlockBackend *blk);
 BlockAcctStats *blk_get_stats(BlockBackend *blk);
 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
diff --git a/block/blkio.c b/block/blkio.c
index 5eae3adfaf..1ff51ff4f3 100644
--- a/block/blkio.c
+++ b/block/blkio.c
@@ -477,7 +477,7 @@ static int coroutine_fn 
blkio_co_pwrite_zeroes(BlockDriverState *bs,
     return cod.ret;
 }
 
-static void blkio_io_unplug(BlockDriverState *bs)
+static void coroutine_fn blkio_co_io_unplug(BlockDriverState *bs)
 {
     BDRVBlkioState *s = bs->opaque;
 
@@ -1006,7 +1006,7 @@ static void blkio_refresh_limits(BlockDriverState *bs, 
Error **errp)
         .bdrv_co_pwritev         = blkio_co_pwritev, \
         .bdrv_co_flush_to_disk   = blkio_co_flush, \
         .bdrv_co_pwrite_zeroes   = blkio_co_pwrite_zeroes, \
-        .bdrv_io_unplug          = blkio_io_unplug, \
+        .bdrv_co_io_unplug       = blkio_co_io_unplug, \
         .bdrv_refresh_limits     = blkio_refresh_limits, \
         .bdrv_register_buf       = blkio_register_buf, \
         .bdrv_unregister_buf     = blkio_unregister_buf, \
diff --git a/block/block-backend.c b/block/block-backend.c
index d10998fe19..e9cc7d291e 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -2325,13 +2325,13 @@ void coroutine_fn blk_co_io_plug(BlockBackend *blk)
     }
 }
 
-void blk_io_unplug(BlockBackend *blk)
+void coroutine_fn blk_co_io_unplug(BlockBackend *blk)
 {
     BlockDriverState *bs = blk_bs(blk);
     IO_CODE();
 
     if (bs) {
-        bdrv_io_unplug(bs);
+        bdrv_co_io_unplug(bs);
     }
 }
 
diff --git a/block/file-posix.c b/block/file-posix.c
index a8abcdd46f..37bf71c5a6 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2148,7 +2148,7 @@ static void coroutine_fn raw_co_io_plug(BlockDriverState 
*bs)
 #endif
 }
 
-static void raw_aio_unplug(BlockDriverState *bs)
+static void coroutine_fn raw_co_io_unplug(BlockDriverState *bs)
 {
     BDRVRawState __attribute__((unused)) *s = bs->opaque;
 #ifdef CONFIG_LINUX_AIO
@@ -3317,7 +3317,7 @@ BlockDriver bdrv_file = {
     .bdrv_co_copy_range_to  = raw_co_copy_range_to,
     .bdrv_refresh_limits = raw_refresh_limits,
     .bdrv_co_io_plug        = raw_co_io_plug,
-    .bdrv_io_unplug = raw_aio_unplug,
+    .bdrv_co_io_unplug      = raw_co_io_unplug,
     .bdrv_attach_aio_context = raw_aio_attach_aio_context,
 
     .bdrv_co_truncate = raw_co_truncate,
@@ -3689,7 +3689,7 @@ static BlockDriver bdrv_host_device = {
     .bdrv_co_copy_range_to  = raw_co_copy_range_to,
     .bdrv_refresh_limits = raw_refresh_limits,
     .bdrv_co_io_plug        = raw_co_io_plug,
-    .bdrv_io_unplug = raw_aio_unplug,
+    .bdrv_co_io_unplug      = raw_co_io_unplug,
     .bdrv_attach_aio_context = raw_aio_attach_aio_context,
 
     .bdrv_co_truncate       = raw_co_truncate,
@@ -3813,7 +3813,7 @@ static BlockDriver bdrv_host_cdrom = {
     .bdrv_co_flush_to_disk  = raw_co_flush_to_disk,
     .bdrv_refresh_limits = raw_refresh_limits,
     .bdrv_co_io_plug        = raw_co_io_plug,
-    .bdrv_io_unplug = raw_aio_unplug,
+    .bdrv_co_io_unplug      = raw_co_io_unplug,
     .bdrv_attach_aio_context = raw_aio_attach_aio_context,
 
     .bdrv_co_truncate    = raw_co_truncate,
@@ -3943,7 +3943,7 @@ static BlockDriver bdrv_host_cdrom = {
     .bdrv_co_flush_to_disk  = raw_co_flush_to_disk,
     .bdrv_refresh_limits = raw_refresh_limits,
     .bdrv_co_io_plug        = raw_co_io_plug,
-    .bdrv_io_unplug = raw_aio_unplug,
+    .bdrv_co_io_unplug      = raw_co_io_unplug,
     .bdrv_attach_aio_context = raw_aio_attach_aio_context,
 
     .bdrv_co_truncate    = raw_co_truncate,
diff --git a/block/io.c b/block/io.c
index c05fb89267..32c744d546 100644
--- a/block/io.c
+++ b/block/io.c
@@ -3153,7 +3153,7 @@ void coroutine_fn bdrv_co_io_plug(BlockDriverState *bs)
     }
 }
 
-void bdrv_io_unplug(BlockDriverState *bs)
+void coroutine_fn bdrv_co_io_unplug(BlockDriverState *bs)
 {
     BdrvChild *child;
     IO_CODE();
@@ -3161,13 +3161,13 @@ void bdrv_io_unplug(BlockDriverState *bs)
     assert(bs->io_plugged);
     if (qatomic_fetch_dec(&bs->io_plugged) == 1) {
         BlockDriver *drv = bs->drv;
-        if (drv && drv->bdrv_io_unplug) {
-            drv->bdrv_io_unplug(bs);
+        if (drv && drv->bdrv_co_io_unplug) {
+            drv->bdrv_co_io_unplug(bs);
         }
     }
 
     QLIST_FOREACH(child, &bs->children, next) {
-        bdrv_io_unplug(child->bs);
+        bdrv_co_io_unplug(child->bs);
     }
 }
 
diff --git a/block/nvme.c b/block/nvme.c
index 1af911e396..eb940f2846 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -1573,7 +1573,7 @@ static void coroutine_fn nvme_co_io_plug(BlockDriverState 
*bs)
     s->plugged = true;
 }
 
-static void nvme_aio_unplug(BlockDriverState *bs)
+static void coroutine_fn nvme_co_io_unplug(BlockDriverState *bs)
 {
     BDRVNVMeState *s = bs->opaque;
     assert(s->plugged);
@@ -1664,7 +1664,7 @@ static BlockDriver bdrv_nvme = {
     .bdrv_attach_aio_context  = nvme_attach_aio_context,
 
     .bdrv_co_io_plug          = nvme_co_io_plug,
-    .bdrv_io_unplug           = nvme_aio_unplug,
+    .bdrv_co_io_unplug        = nvme_co_io_unplug,
 
     .bdrv_register_buf        = nvme_register_buf,
     .bdrv_unregister_buf      = nvme_unregister_buf,
-- 
2.38.1