qemu-devel.nongnu.org archive mirror
 help / color / mirror / Atom feed
* [RFC PATCH] block/io.c: Flush parent for quorum in generic code
@ 2021-05-12  7:49 Zhang Chen
  2021-05-13 14:25 ` Stefan Hajnoczi
  2021-05-18  6:33 ` Lukas Straub
  0 siblings, 2 replies; 6+ messages in thread
From: Zhang Chen @ 2021-05-12  7:49 UTC (permalink / raw)
  To: Kevin Wolf, Max Reitz, Stefan Hajnoczi, Fam Zheng, qemu-dev, qemu-block
  Cc: Zhang Chen, Minghao Yuan, Zhang Chen

Fix the issue from this patch:
[PATCH] block: Flush all children in generic code
From 883833e29cb800b4d92b5d4736252f4004885191

Quorum driver do not have the primary child.
It will caused guest block flush issue when use quorum and NBD.
The vm guest flushes failed，and then guest filesystem is shutdown.

Signed-off-by: Zhang Chen <chen.zhang@intel.com>
Reported-by: Minghao Yuan <meeho@qq.com>
---
 block/io.c | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/block/io.c b/block/io.c
index 35b6c56efc..4dc1873cb9 100644
--- a/block/io.c
+++ b/block/io.c
@@ -2849,6 +2849,13 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
     BdrvChild *child;
     int current_gen;
     int ret = 0;
+    bool no_primary_child = false;
+
+    /* Quorum drivers do not have the primary child. */
+    if (!primary_child) {
+        primary_child = bs->file;
+        no_primary_child = true;
+    }
 
     bdrv_inc_in_flight(bs);
 
@@ -2886,12 +2893,12 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
 
     /* But don't actually force it to the disk with cache=unsafe */
     if (bs->open_flags & BDRV_O_NO_FLUSH) {
-        goto flush_children;
+        goto flush_data;
     }
 
     /* Check if we really need to flush anything */
     if (bs->flushed_gen == current_gen) {
-        goto flush_children;
+        goto flush_data;
     }
 
     BLKDBG_EVENT(primary_child, BLKDBG_FLUSH_TO_DISK);
@@ -2938,13 +2945,19 @@ int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
     /* Now flush the underlying protocol.  It will also have BDRV_O_NO_FLUSH
      * in the case of cache=unsafe, so there are no useless flushes.
      */
-flush_children:
-    ret = 0;
-    QLIST_FOREACH(child, &bs->children, next) {
-        if (child->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) {
-            int this_child_ret = bdrv_co_flush(child->bs);
-            if (!ret) {
-                ret = this_child_ret;
+flush_data:
+    if (no_primary_child) {
+        /* Flush parent */
+        ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0;
+    } else {
+        /* Flush childrens */
+        ret = 0;
+        QLIST_FOREACH(child, &bs->children, next) {
+            if (child->perm & (BLK_PERM_WRITE | BLK_PERM_WRITE_UNCHANGED)) {
+                int this_child_ret = bdrv_co_flush(child->bs);
+                if (!ret) {
+                    ret = this_child_ret;
+                }
             }
         }
     }
-- 
2.25.1



^ permalink raw reply related	[flat|nested] 6+ messages in thread
end of thread, other threads:[~2021-05-18  8:43 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-05-12  7:49 [RFC PATCH] block/io.c: Flush parent for quorum in generic code Zhang Chen
2021-05-13 14:25 ` Stefan Hajnoczi
2021-05-17 17:59   ` Zhang, Chen
2021-05-18  6:33 ` Lukas Straub
2021-05-18  7:38   ` Kevin Wolf
2021-05-18  8:39     ` Zhang, Chen

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).