From 054355934a59bf4c08aa994fbab97a0f96cab31c Mon Sep 17 00:00:00 2001
From: Igor Fedotov <ifedotov@suse.com>
Date: Thu, 9 May 2019 19:23:30 +0300
Subject: [PATCH] os/bluestore: protect BlueFS::FileReader::buf

Now this buffer might be accessed from BlueRocksRandomAccessFile
which is intended for multi-threading access. Hence we need a
proper protection for the buffer.

Signed-off-by: Igor Fedotov <ifedotov@suse.com>
---
 src/os/bluestore/BlueFS.cc | 12 ++++++++++--
 src/os/bluestore/BlueFS.h  |  5 +++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/os/bluestore/BlueFS.cc b/src/os/bluestore/BlueFS.cc
index 35d6c3bafca..d8587c8d2cb 100644
--- a/src/os/bluestore/BlueFS.cc
+++ b/src/os/bluestore/BlueFS.cc
@@ -1378,10 +1378,10 @@ int BlueFS::_read_random(
   logger->inc(l_bluefs_read_random_count, 1);
   logger->inc(l_bluefs_read_random_bytes, len);
 
-
+  std::shared_lock s_lock(h->lock);
   while (len > 0) {
     if (off < buf->bl_off || off >= buf->get_buf_end()) {
-
+      s_lock.unlock();
       uint64_t x_off = 0;
       auto p = h->file->fnode.seek(off, &x_off);
       uint64_t l = std::min(p->length - x_off, static_cast<uint64_t>(len));
@@ -1398,6 +1398,9 @@ int BlueFS::_read_random(
 
       logger->inc(l_bluefs_read_random_disk_count, 1);
       logger->inc(l_bluefs_read_random_disk_bytes, l);
+      if (len > 0) {
+	s_lock.lock();
+      }
     } else {
       auto left = buf->get_buf_remaining(off);
       int r = std::min(len, left);
@@ -1468,9 +1471,12 @@ int BlueFS::_read(
     outbl->clear();
 
   int ret = 0;
+  std::shared_lock s_lock(h->lock);
   while (len > 0) {
     size_t left;
     if (off < buf->bl_off || off >= buf->get_buf_end()) {
+      s_lock.unlock();
+      std::unique_lock u_lock(h->lock);
       buf->bl.clear();
       buf->bl_off = off & super.block_mask();
       uint64_t x_off = 0;
@@ -1490,6 +1496,8 @@ int BlueFS::_read(
       int r = bdev[p->bdev]->read(p->offset + x_off, l, &buf->bl, ioc[p->bdev],
 				  cct->_conf->bluefs_buffered_io);
       ceph_assert(r == 0);
+      u_lock.unlock();
+      s_lock.lock();
     }
     left = buf->get_buf_remaining(off);
     dout(20) << __func__ << " left 0x" << std::hex << left
diff --git a/src/os/bluestore/BlueFS.h b/src/os/bluestore/BlueFS.h
index 12c25ca2387..780b3d2475a 100644
--- a/src/os/bluestore/BlueFS.h
+++ b/src/os/bluestore/BlueFS.h
@@ -231,6 +231,11 @@ public:
     bool random;
     bool ignore_eof;        ///< used when reading our log file
 
+    ceph::shared_mutex lock {
+     ceph::make_shared_mutex(std::string(), false, false, false)
+    };
+
+
     FileReader(FileRef f, uint64_t mpf, bool rand, bool ie)
       : file(f),
 	buf(mpf),
-- 
2.39.5