From 7672ceb4f09c81ee7a2d5e8672e2c402c3206b4e Mon Sep 17 00:00:00 2001
From: luo rixin <luorixin@huawei.com>
Date: Wed, 14 Sep 2022 19:50:01 +0800
Subject: [PATCH] os/bluestore: use direct write in
 BlueStore::_write_bdev_label

On AArch64 with kernel page size 64K, it occurs occasionally
"OSD::init(): unable to read osd superblock" when deploying osd.
As bluestore use direct write to write the superblock at 0x2000~1000
and BlueStore::_write_bdev_label use buffer write to write label at
0x0~1000, The OS flush the buffer write algined to page size, it will
overwrite the superblock(0x2000~1000). Use driect write to avoid
overwriting the superblock.

Fixes: https://tracker.ceph.com/issues/57537
Signed-off-by: luo rixin <luorixin@huawei.com>
---
 src/os/bluestore/BlueStore.cc | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 8b893be79d1..534fe780f27 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -5104,13 +5104,14 @@ int BlueStore::_write_bdev_label(CephContext *cct,
   z.zero();
   bl.append(std::move(z));
 
-  int fd = TEMP_FAILURE_RETRY(::open(path.c_str(), O_WRONLY|O_CLOEXEC));
+  int fd = TEMP_FAILURE_RETRY(::open(path.c_str(), O_WRONLY|O_CLOEXEC|O_DIRECT));
   if (fd < 0) {
     fd = -errno;
     derr << __func__ << " failed to open " << path << ": " << cpp_strerror(fd)
 	 << dendl;
     return fd;
   }
+  bl.rebuild_aligned_size_and_memory(BDEV_LABEL_BLOCK_SIZE, BDEV_LABEL_BLOCK_SIZE, IOV_MAX);
   int r = bl.write_fd(fd);
   if (r < 0) {
     derr << __func__ << " failed to write to " << path
-- 
2.20.1.windows.1