加入 Gitee
与超过 1200万 开发者一起发现、参与优秀开源项目,私有仓库也完全免费 :)
免费加入
文件
该仓库未声明开源许可证文件(LICENSE),使用请关注具体项目描述及其代码上游依赖。
克隆/下载
block-file-posix-Let-post-EOF-fallocate-serialize.patch 2.59 KB
一键复制 编辑 原始数据 按行查看 历史
From 7db05c8a732fbdc986a40aadf0de6dd23057d044 Mon Sep 17 00:00:00 2001
From: Max Reitz <mreitz@redhat.com>
Date: Fri, 1 Nov 2019 16:25:10 +0100
Subject: [PATCH] block/file-posix: Let post-EOF fallocate serialize
The XFS kernel driver has a bug that may cause data corruption for qcow2
images as of qemu commit c8bb23cbdbe32f. We can work around it by
treating post-EOF fallocates as serializing up until infinity (INT64_MAX
in practice).
Cc: qemu-stable@nongnu.org
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20191101152510.11719-4-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
(cherry picked from commit 292d06b925b2787ee6f2430996b95651cae42fce)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---
block/file-posix.c | 36 ++++++++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)
diff --git a/block/file-posix.c b/block/file-posix.c
index 992eb4a798..c5df61b477 100644
--- a/block/file-posix.c
+++ b/block/file-posix.c
@@ -2623,6 +2623,42 @@ raw_do_pwrite_zeroes(BlockDriverState *bs, int64_t offset, int bytes,
RawPosixAIOData acb;
ThreadPoolFunc *handler;
+#ifdef CONFIG_FALLOCATE
+ if (offset + bytes > bs->total_sectors * BDRV_SECTOR_SIZE) {
+ BdrvTrackedRequest *req;
+ uint64_t end;
+
+ /*
+ * This is a workaround for a bug in the Linux XFS driver,
+ * where writes submitted through the AIO interface will be
+ * discarded if they happen beyond a concurrently running
+ * fallocate() that increases the file length (i.e., both the
+ * write and the fallocate() happen beyond the EOF).
+ *
+ * To work around it, we extend the tracked request for this
+ * zero write until INT64_MAX (effectively infinity), and mark
+ * it as serializing.
+ *
+ * We have to enable this workaround for all filesystems and
+ * AIO modes (not just XFS with aio=native), because for
+ * remote filesystems we do not know the host configuration.
+ */
+
+ req = bdrv_co_get_self_request(bs);
+ assert(req);
+ assert(req->type == BDRV_TRACKED_WRITE);
+ assert(req->offset <= offset);
+ assert(req->offset + req->bytes >= offset + bytes);
+
+ end = INT64_MAX & -(uint64_t)bs->bl.request_alignment;
+ req->bytes = end - req->offset;
+ req->overlap_bytes = req->bytes;
+
+ bdrv_mark_request_serialising(req, bs->bl.request_alignment);
+ bdrv_wait_serialising_requests(req);
+ }
+#endif
+
acb = (RawPosixAIOData) {
.bs = bs,
.aio_fildes = s->fd,
--
2.23.0
马建仓 AI 助手
尝试更多
代码解读
代码找茬
代码优化