From: Christian Kamm <mail@ckamm.de>
Date: Tue, 12 Sep 2017 11:39:45 +0000 (+0200)
Subject: Journal: Fall back to DELETE on IO error #5723
X-Git-Tag: archive/raspbian/3.16.7-1_deb13u1+rpi1~1^2~701^2~113
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=4acb70e79dc7ce500168fd7e7338248fa06e9777;p=nextcloud-desktop.git

Journal: Fall back to DELETE on IO error #5723

Also add logging of extended error codes for this IO error, maybe we can
become more specific about which situations should trigger a journal
mode switch.
---

diff --git a/src/libsync/ownsql.cpp b/src/libsync/ownsql.cpp
index 759f1981d..e66fdfb3e 100644
--- a/src/libsync/ownsql.cpp
+++ b/src/libsync/ownsql.cpp
@@ -280,6 +280,12 @@ bool SqlQuery::exec()
         if (_errId != SQLITE_DONE && _errId != SQLITE_ROW) {
             _error = QString::fromUtf8(sqlite3_errmsg(_db));
             qCWarning(lcSql) << "Sqlite exec statement error:" << _errId << _error << "in" << _sql;
+            if (_errId == SQLITE_IOERR) {
+                qCWarning(lcSql) << "IOERR extended errcode: " << sqlite3_extended_errcode(_db);
+#if SQLITE_VERSION_NUMBER >= 3012000
+                qCWarning(lcSql) << "IOERR system errno: " << sqlite3_system_errno(_db);
+#endif
+            }
         } else {
             qCDebug(lcSql) << "Last exec affected" << numRowsAffected() << "rows.";
         }
diff --git a/src/libsync/syncjournaldb.cpp b/src/libsync/syncjournaldb.cpp
index 6706fb65e..f4d3510dd 100644
--- a/src/libsync/syncjournaldb.cpp
+++ b/src/libsync/syncjournaldb.cpp
@@ -323,7 +323,26 @@ bool SyncJournalDb::checkConnect()
                         ");");
 
     if (!createQuery.exec()) {
-        return sqlFail("Create table metadata", createQuery);
+        bool fail = true;
+
+        // In certain situations the io error can be avoided by switching
+        // to the DELETE journal mode, see #5723
+        if (createQuery.errorId() == SQLITE_IOERR) {
+            qCWarning(lcDb) << "IO error on table creation, attempting with DELETE journal mode";
+
+            pragma1.prepare(QString("PRAGMA journal_mode=DELETE;"));
+            if (!pragma1.exec()) {
+                return sqlFail("Set PRAGMA journal_mode", pragma1);
+            }
+            pragma1.next();
+            qCInfo(lcDb) << "sqlite3 journal_mode=" << pragma1.stringValue(0);
+
+            if (createQuery.exec()) {
+                fail = false;
+            }
+        }
+        if (fail)
+            return sqlFail("Create table metadata", createQuery);
     }
 
     createQuery.prepare("CREATE TABLE IF NOT EXISTS downloadinfo("