From 0fd8c17c54bcbdae8480ed91a1ba8dbb2bb5f203 Mon Sep 17 00:00:00 2001 From: Alberto Bertogli Date: Sat, 28 Mar 2009 23:06:40 -0300 Subject: [PATCH 28/32] Call fdatasync() after writing to the real file If O_SYNC was not passed to jopen(), then we could loose data because jtrans_commit() assumes writes to the file are synchronous. That behaviour was undocumented, so the user could have assumed O_SYNC was not necessary. This patch implements a much more sane semantic by calling fdatasync() on the file fd after writing the transaction when lingering transactions are not enabled, avoiding the need to open the file with O_SYNC. Signed-off-by: Alberto Bertogli --- UPGRADING | 4 ++++ libjio/trans.c | 3 +++ 2 files changed, 7 insertions(+), 0 deletions(-) diff --git a/UPGRADING b/UPGRADING index 72b9c9e..2d3f8fd 100644 --- a/UPGRADING +++ b/UPGRADING @@ -11,6 +11,10 @@ take much. If it's mandatory, it will be noted. If you want to see what motivated the changes, see the changelog or just ask. +0.24 -> 0.25 +* It is no longer necessary to pass O_SYNC to jopen() if lingering + transactions are not in use. + 0.22 -> 0.24 * The return values of jfsck() have changed, so applications using it need to be recompiled. diff --git a/libjio/trans.c b/libjio/trans.c index bd0eab5..8f003d4 100644 --- a/libjio/trans.c +++ b/libjio/trans.c @@ -416,6 +416,9 @@ ssize_t jtrans_commit(struct jtrans *ts) ts->fs->ltrans = linger; pthread_mutex_unlock(&(ts->fs->ltlock)); } else { + if (fdatasync(ts->fs->fd) != 0) + goto rollback_exit; + /* the transaction has been applied, so we cleanup and remove * it from the disk */ unlink(name); -- 1.6.2.rc0.226.gf08f