From f7ab34ea723ed304b19698efca85d6f40cecd99b Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 3 Apr 2009 01:34:35 -0400 Subject: ext3: Add replace-on-truncate hueristics for data=writeback mode In data=writeback mode, start an asynchronous flush when closing a file which had been previously truncated down to zero. This lowers the probability of data loss in the case of applications that attempt to replace a file using truncate. Signed-off-by: "Theodore Ts'o" --- fs/ext3/file.c | 4 ++++ fs/ext3/inode.c | 3 +++ 2 files changed, 7 insertions(+) (limited to 'fs/ext3') diff --git a/fs/ext3/file.c b/fs/ext3/file.c index 3be1e0689c9..4a04cbb1c23 100644 --- a/fs/ext3/file.c +++ b/fs/ext3/file.c @@ -33,6 +33,10 @@ */ static int ext3_release_file (struct inode * inode, struct file * filp) { + if (EXT3_I(inode)->i_state & EXT3_STATE_FLUSH_ON_CLOSE) { + filemap_flush(inode->i_mapping); + EXT3_I(inode)->i_state &= ~EXT3_STATE_FLUSH_ON_CLOSE; + } /* if we are the last writer on the inode, drop the block reservation */ if ((filp->f_mode & FMODE_WRITE) && (atomic_read(&inode->i_writecount) == 1)) diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index 5fa453b49a6..0f5bca0d82f 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -2346,6 +2346,9 @@ void ext3_truncate(struct inode *inode) if (!ext3_can_truncate(inode)) return; + if (inode->i_size == 0 && ext3_should_writeback_data(inode)) + ei->i_state |= EXT3_STATE_FLUSH_ON_CLOSE; + /* * We have to lock the EOF page here, because lock_page() nests * outside journal_start(). -- cgit v1.2.3