From: David Edmondson <david.edmondson@oracle.com>
To: qemu-devel@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
qemu-block@nongnu.org, Stefan Weil <sw@weilnetz.de>,
Max Reitz <mreitz@redhat.com>,
David Edmondson <david.edmondson@oracle.com>,
Stefan Hajnoczi <stefanha@redhat.com>
Subject: [RFC PATCH 2/4] block/vdi: Don't assume that blocks are larger than VdiHeader
Date: Tue, 9 Mar 2021 10:21:55 +0000 [thread overview]
Message-ID: <20210309102157.365356-3-david.edmondson@oracle.com> (raw)
In-Reply-To: <20210309102157.365356-1-david.edmondson@oracle.com>
Given that the block size is read from the header of the VDI file, a
wide variety of sizes might be seen. Rather than re-using a block
sized memory region when writing the VDI header, allocate an
appropriately sized buffer.
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
---
block/vdi.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/block/vdi.c b/block/vdi.c
index 2a6dc26124..548f8a057b 100644
--- a/block/vdi.c
+++ b/block/vdi.c
@@ -696,18 +696,20 @@ nonallocating_write:
if (block) {
/* One or more new blocks were allocated. */
- VdiHeader *header = (VdiHeader *) block;
+ VdiHeader *header;
uint8_t *base;
uint64_t offset;
uint32_t n_sectors;
+ g_free(block);
+ header = g_malloc(sizeof(*header));
+
logout("now writing modified header\n");
assert(VDI_IS_ALLOCATED(bmap_first));
*header = s->header;
vdi_header_to_le(header);
- ret = bdrv_pwrite(bs->file, 0, block, sizeof(VdiHeader));
- g_free(block);
- block = NULL;
+ ret = bdrv_pwrite(bs->file, 0, header, sizeof(*header));
+ g_free(header);
if (ret < 0) {
return ret;
--
2.30.1
next prev parent reply other threads:[~2021-03-09 10:25 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-09 10:21 [RFC PATCH 0/4] coroutine rwlock downgrade fix, minor VDI changes David Edmondson
2021-03-09 10:21 ` [RFC PATCH 1/4] block/vdi: When writing new bmap entry fails, don't leak the buffer David Edmondson
2021-03-09 11:09 ` Philippe Mathieu-Daudé
2021-03-09 11:58 ` David Edmondson
2021-03-09 12:06 ` Philippe Mathieu-Daudé
2021-03-09 13:07 ` Paolo Bonzini
2021-03-09 10:21 ` David Edmondson [this message]
2021-03-09 10:21 ` [RFC PATCH 3/4] coroutine/mutex: Store the coroutine in the CoWaitRecord only once David Edmondson
2021-03-09 10:49 ` Paolo Bonzini
2021-03-09 11:11 ` Philippe Mathieu-Daudé
2021-03-09 10:21 ` [RFC PATCH 4/4] coroutine/rwlock: Wake writers in preference to readers David Edmondson
2021-03-09 10:59 ` Paolo Bonzini
2021-03-09 11:06 ` Paolo Bonzini
2021-03-09 11:57 ` David Edmondson
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