[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH V8 3/4] block: Add backing file loop check in change
From: |
Xu Wang |
Subject: |
[Qemu-devel] [PATCH V8 3/4] block: Add backing file loop check in change_backing_file() |
Date: |
Fri, 15 Nov 2013 01:37:22 -0500 |
Backing file loop should be checked before calling change_backing_
file(). If loop appeared, this calling should be stopped and an
error printed.
Signed-off-by: Xu Wang <address@hidden>
---
block.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/block.c b/block.c
index 6fbc702..2d58f12 100644
--- a/block.c
+++ b/block.c
@@ -2068,6 +2068,7 @@ static void coroutine_fn
wait_for_overlapping_requests(BlockDriverState *bs,
* Return values:
* 0 - success
* -EINVAL - backing format specified, but no file
+ * -EIO - generic I/O error (may happen for all errors)
* -ENOSPC - can't update the backing file because no space is left in the
* image file header
* -ENOTSUP - format driver doesn't support changing the backing file
@@ -2076,6 +2077,7 @@ int bdrv_change_backing_file(BlockDriverState *bs,
const char *backing_file, const char *backing_fmt)
{
BlockDriver *drv = bs->drv;
+ Error *local_err = NULL;
int ret;
/* Backing file format doesn't make sense without a backing file */
@@ -2083,6 +2085,13 @@ int bdrv_change_backing_file(BlockDriverState *bs,
return -EINVAL;
}
+ /* Check if loop exists in backing files chain after change */
+ if (!bdrv_backing_chain_okay(backing_file, backing_fmt, bs->filename,
+ &local_err)) {
+ error_report("Backing file check: %s", error_get_pretty(local_err));
+ return -EIO;
+ }
+
if (drv->bdrv_change_backing_file != NULL) {
ret = drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
} else {
--
1.8.1.4