diff mbox

[v8,13/16] block: Add blk_remove_all_bs()

Message ID 1453917600-2663-14-git-send-email-mreitz@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Max Reitz Jan. 27, 2016, 5:59 p.m. UTC 
When bdrv_close_all() is called, instead of force-closing all root
BlockDriverStates, it is better to just drop the reference from all
BlockBackends and let them be closed automatically. This prevents BDS
from getting closed that are still referenced by other BDS, which may
result in loss of cached data.

This patch adds a function for doing that, but does not yet incorporate
it in bdrv_close_all().

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
---
 block/block-backend.c          | 15 +++++++++++++++
 include/sysemu/block-backend.h |  1 +
 2 files changed, 16 insertions(+)
diff mbox

Patch

diff --git a/block/block-backend.c b/block/block-backend.c
index 7f5ad59..ebdf78a 100644
--- a/block/block-backend.c
+++ b/block/block-backend.c
@@ -223,6 +223,21 @@  void blk_unref(BlockBackend *blk)
     }
 }
 
+void blk_remove_all_bs(void)
+{
+    BlockBackend *blk;
+
+    QTAILQ_FOREACH(blk, &blk_backends, link) {
+        AioContext *ctx = blk_get_aio_context(blk);
+
+        aio_context_acquire(ctx);
+        if (blk->bs) {
+            blk_remove_bs(blk);
+        }
+        aio_context_release(ctx);
+    }
+}
+
 /*
  * Return the BlockBackend after @blk.
  * If @blk is null, return the first one.
diff --git a/include/sysemu/block-backend.h b/include/sysemu/block-backend.h
index ae4efb4..ec30331 100644
--- a/include/sysemu/block-backend.h
+++ b/include/sysemu/block-backend.h
@@ -68,6 +68,7 @@  BlockBackend *blk_new_open(const char *name, const char *filename,
 int blk_get_refcnt(BlockBackend *blk);
 void blk_ref(BlockBackend *blk);
 void blk_unref(BlockBackend *blk);
+void blk_remove_all_bs(void);
 const char *blk_name(BlockBackend *blk);
 BlockBackend *blk_by_name(const char *name);
 BlockBackend *blk_next(BlockBackend *blk);