[RFC PATCH 2/2] jbd: Stabilize pages during writes when in ordered mode
From: Darrick J. Wong <hidden>
Date: 2012-11-22 02:36:45
Also in:
linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
When writing buffers out to disk ahead of committing a transaction, set the Stable bit on the page to prevent others from wandering in and modifying the page. Signed-off-by: Darrick J. Wong <redacted> --- fs/jbd/commit.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index 86b39b1..b1f0eed 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c@@ -155,13 +155,29 @@ static int journal_write_commit_record(journal_t *journal, return (ret == -EIO); } +static void end_stable_write_sync(struct buffer_head *bh, int uptodate) +{ + clear_page_stable(bh->b_page); + end_buffer_write_sync(bh, uptodate); +} + static void journal_do_submit_data(struct buffer_head **wbuf, int bufs, int write_op) { int i; for (i = 0; i < bufs; i++) { - wbuf[i]->b_end_io = end_buffer_write_sync; + struct page *p = wbuf[i]->b_page; + if (TestSetPageStable(p)) + wbuf[i]->b_end_io = end_buffer_write_sync; + else + wbuf[i]->b_end_io = end_stable_write_sync; + + if (trylock_page(p)) { + clear_page_dirty_for_io(p); + unlock_page(p); + } + /* We use-up our safety reference in submit_bh() */ submit_bh(write_op, wbuf[i]); }