Bug 1834043 - Add a configure option to disable Sqlite auxiliary file…

…s persistence. r=glandium,tjr Not using a pref because Storage has connections using helper threads and the main thread, thus we prefer to avoid mutex costs for a pref we'll likely not use in Firefox. Also using a "once" pref would require some coordination because Storage may try to lazy init once prefs from different threads concurrently, causing potential deadlocks. Differential Revision: https://phabricator.services.mozilla.com/D183724
dothq · Aug 1, 2023 · ae32ce0 · ae32ce0
1 parent f104bcd
commit ae32ce0
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Showing 5 changed files with 26 additions and 2 deletions.
diff --git a/browser/config/mozconfigs/win32/mingwclang b/browser/config/mozconfigs/win32/mingwclang
@@ -24,8 +24,9 @@ ac_add_options --with-toolchain-prefix=i686-w64-mingw32-
 ac_add_options --disable-warnings-as-errors
 mk_add_options "export WIDL_TIME_OVERRIDE=0"
 
-# This replicates Tor's configuration
+# These replicate Tor's configuration
 ac_add_options --enable-proxy-bypass-protection
+ac_add_options --enable-disk-remnant-avoidance
 
 # These aren't supported on mingw at this time
 ac_add_options --disable-webrtc # Bug 1393901

diff --git a/browser/config/mozconfigs/win64/mingwclang b/browser/config/mozconfigs/win64/mingwclang
@@ -24,8 +24,9 @@ ac_add_options --with-toolchain-prefix=x86_64-w64-mingw32-
 ac_add_options --disable-warnings-as-errors
 mk_add_options "export WIDL_TIME_OVERRIDE=0"
 
-# This replicates Tor's configuration
+# These replicate Tor's configuration
 ac_add_options --enable-proxy-bypass-protection
+ac_add_options --enable-disk-remnant-avoidance
 
 # These aren't supported on mingw at this time
 ac_add_options --disable-webrtc # Bug 1393901

diff --git a/storage/BaseVFS.cpp b/storage/BaseVFS.cpp
@@ -84,6 +84,7 @@ int BaseCheckReservedLock(sqlite3_file* pFile, int* pResOut) {
 }
 
 int BaseFileControl(sqlite3_file* pFile, int op, void* pArg) {
+#if defined(MOZ_SQLITE_PERSIST_AUXILIARY_FILES)
   // Persist auxiliary files (-shm and -wal) on disk, because creating and
   // deleting them may be expensive on slow storage.
   // Only do this when there is a journal size limit, so the journal is
@@ -96,6 +97,7 @@ int BaseFileControl(sqlite3_file* pFile, int op, void* pArg) {
     *static_cast<int*>(pArg) = 1;
     return SQLITE_OK;
   }
+#endif
   BaseFile* p = (BaseFile*)pFile;
   return p->pReal->pMethods->xFileControl(p->pReal, op, pArg);
 }

diff --git a/storage/moz.build b/storage/moz.build
@@ -101,6 +101,10 @@ if CONFIG["MOZ_THUNDERBIRD"] or CONFIG["MOZ_SUITE"]:
 # will need to change it here as well.
 DEFINES["SQLITE_MAX_LIKE_PATTERN_LENGTH"] = 50000
 
+# Disable auxiliary files persistence if requested.
+if not CONFIG["MOZ_AVOID_DISK_REMNANT_ON_CLOSE"]:
+    DEFINES["MOZ_SQLITE_PERSIST_AUXILIARY_FILES"] = 1
+
 LOCAL_INCLUDES += [
     "/dom/base",
     "/third_party/sqlite3/src",

diff --git a/toolkit/moz.configure b/toolkit/moz.configure
@@ -2707,6 +2707,22 @@ set_config("MOZ_NEW_NOTIFICATION_STORE", True, when=new_notification_store)
 set_define("MOZ_NEW_NOTIFICATION_STORE", True, when=new_notification_store)
 
 
+# Auxiliary files persistence on application close
+# ==============================================================
+
+option(
+    "--enable-disk-remnant-avoidance",
+    help="Prevent persistence of auxiliary files on application close",
+)
+
+
+set_config(
+    "MOZ_AVOID_DISK_REMNANT_ON_CLOSE",
+    True,
+    when="--enable-disk-remnant-avoidance",
+)
+
+
 # Glean SDK Integration Crate
 # ==============================================================