From 86963918965eb8fe0c8ae009e7c1b4c630f533d5 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 16 Feb 2010 20:37:12 +0100 Subject: jbd: Delay discarding buffers in journal_unmap_buffer Delay discarding buffers in journal_unmap_buffer until we know that "add to orphan" operation has definitely been committed, otherwise the log space of committing transation may be freed and reused before truncate get committed, updates may get lost if crash happens. This patch is a backport of JBD2 fix by dingdinghua . Signed-off-by: Jan Kara --- fs/jbd/commit.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'fs/jbd/commit.c') diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c index 4bd882548c45..2c90e3ef625f 100644 --- a/fs/jbd/commit.c +++ b/fs/jbd/commit.c @@ -862,12 +862,12 @@ restart_loop: /* A buffer which has been freed while still being * journaled by a previous transaction may end up still * being dirty here, but we want to avoid writing back - * that buffer in the future now that the last use has - * been committed. That's not only a performance gain, - * it also stops aliasing problems if the buffer is left - * behind for writeback and gets reallocated for another + * that buffer in the future after the "add to orphan" + * operation been committed, That's not only a performance + * gain, it also stops aliasing problems if the buffer is + * left behind for writeback and gets reallocated for another * use in a different page. */ - if (buffer_freed(bh)) { + if (buffer_freed(bh) && !jh->b_next_transaction) { clear_buffer_freed(bh); clear_buffer_jbddirty(bh); } -- cgit v1.2.3