From c8a12aa94bc78357d008735978c6bb6c0204d4f0 Mon Sep 17 00:00:00 2001
From: Peter Dillinger <peterd@fb.com>
Date: Fri, 25 Sep 2020 13:33:05 -0700
Subject: [PATCH] EnableFileDeletions only read field while holding mutex
(#7435)
Summary:
Possible fix for a TSAN issue reported in EnableFileDeletions.
disable_delete_obsolete_files_ should only be accessed holding the db
mutex, but for logging it was being accessed outside holding the mutex,
now fixed.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/7435
Test Plan: existing tests, watch for recurrence
Reviewed By: ltamasi
Differential Revision: D23917578
Pulled By: pdillinger
fbshipit-source-id: 8573025bca3f6fe169b24b87bbfc4ce9667b0482
---
db/db_impl/db_impl_files.cc | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/db/db_impl/db_impl_files.cc b/db/db_impl/db_impl_files.cc
index 7e51d2c3c9..0953bf3da8 100644
--- a/db/db_impl/db_impl_files.cc
+++ b/db/db_impl/db_impl_files.cc
@@ -58,7 +58,7 @@ Status DBImpl::EnableFileDeletions(bool force) {
// Job id == 0 means that this is not our background process, but rather
// user thread
JobContext job_context(0);
- bool file_deletion_enabled = false;
+ int saved_counter; // initialize on all paths
{
InstrumentedMutexLock l(&mutex_);
if (force) {
@@ -67,13 +67,13 @@ Status DBImpl::EnableFileDeletions(bool force) {
} else if (disable_delete_obsolete_files_ > 0) {
--disable_delete_obsolete_files_;
}
- if (disable_delete_obsolete_files_ == 0) {
- file_deletion_enabled = true;
+ saved_counter = disable_delete_obsolete_files_;
+ if (saved_counter == 0) {
FindObsoleteFiles(&job_context, true);
bg_cv_.SignalAll();
}
}
- if (file_deletion_enabled) {
+ if (saved_counter == 0) {
ROCKS_LOG_INFO(immutable_db_options_.info_log, "File Deletions Enabled");
if (job_context.HaveSomethingToDelete()) {
PurgeObsoleteFiles(job_context);
@@ -81,7 +81,7 @@ Status DBImpl::EnableFileDeletions(bool force) {
} else {
ROCKS_LOG_WARN(immutable_db_options_.info_log,
"File Deletions Enable, but not really enabled. Counter: %d",
- disable_delete_obsolete_files_);
+ saved_counter);
}
job_context.Clean();
LogFlush(immutable_db_options_.info_log);