From: Ilya Dryomov <idryomov@gmail.com>
Date: Sun, 12 May 2024 10:35:46 +0000 (+0200)
Subject: osdc/Striper: relax assert in assemble_result() for raw buffers
X-Git-Tag: v17.2.8~295^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=1e633af5eea4203ea248b883363468406cd967d8;p=ceph.git

osdc/Striper: relax assert in assemble_result() for raw buffers

The previous commit uncovered an old bug, introduced in commit
9867804c2058 ("Striper: Add function 'assemble_result(CephContext *cct,
char *buffer, size_t len)' in StripedReadResult.").  The buffer is
allowed to be NULL when assemble_result() is called -- it becomes
a problem only if some data was read.

Strengthen ZeroLengthRead and ZeroLengthWrite tests to cover both
a bogus pointer and a NULL pointer for buffer.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
(cherry picked from commit e6773a92f774b0f2748f2565ca4f53b6ace9fbdf)
---

diff --git a/src/osdc/Striper.cc b/src/osdc/Striper.cc
index 6f162e901fe..69bdda06f84 100644
--- a/src/osdc/Striper.cc
+++ b/src/osdc/Striper.cc
@@ -485,13 +485,14 @@ void Striper::StripedReadResult::assemble_result(CephContext *cct,
 
 void Striper::StripedReadResult::assemble_result(CephContext *cct, char *buffer, size_t length)
 {
-
-  ceph_assert(buffer && length == total_intended_len);
+  ceph_assert(length == total_intended_len);
 
   map<uint64_t,pair<bufferlist,uint64_t> >::reverse_iterator p = partial.rbegin();
   if (p == partial.rend())
     return;
 
+  ceph_assert(buffer);
+
   uint64_t curr = length;
   uint64_t end = p->first + p->second.second;
   while (p != partial.rend()) {
diff --git a/src/test/librbd/test_librbd.cc b/src/test/librbd/test_librbd.cc
index f4b4b3907bf..ca47805e506 100644
--- a/src/test/librbd/test_librbd.cc
+++ b/src/test/librbd/test_librbd.cc
@@ -7290,8 +7290,12 @@ TEST_F(TestLibRBD, ZeroLengthWrite)
   ASSERT_EQ(0, create_image(ioctx, name.c_str(), size, &order));
   ASSERT_EQ(0, rbd_open(ioctx, name.c_str(), &image, NULL));
 
-  char read_data[1];
+  const char data[] = "blah";
+  ASSERT_EQ(0, rbd_write(image, 0, 0, data));
+  ASSERT_EQ(0, rbd_write(image, 0, 0, (char*)0x123));
   ASSERT_EQ(0, rbd_write(image, 0, 0, NULL));
+
+  char read_data[1];
   ASSERT_EQ(1, rbd_read(image, 0, 1, read_data));
   ASSERT_EQ('\0', read_data[0]);
 
@@ -7343,6 +7347,8 @@ TEST_F(TestLibRBD, ZeroLengthRead)
 
   char read_data[1];
   ASSERT_EQ(0, rbd_read(image, 0, 0, read_data));
+  ASSERT_EQ(0, rbd_read(image, 0, 0, (char*)0x123));
+  ASSERT_EQ(0, rbd_read(image, 0, 0, NULL));
 
   ASSERT_EQ(0, rbd_close(image));