From 994fc28c7b1e697ac56befe4aecabf23f0689f46 Mon Sep 17 00:00:00 2001 From: Zach Brown Date: Thu, 15 Dec 2005 14:28:17 -0800 Subject: [PATCH] add AOP_TRUNCATED_PAGE, prepend AOP_ to WRITEPAGE_ACTIVATE readpage(), prepare_write(), and commit_write() callers are updated to understand the special return code AOP_TRUNCATED_PAGE in the style of writepage() and WRITEPAGE_ACTIVATE. AOP_TRUNCATED_PAGE tells the caller that the callee has unlocked the page and that the operation should be tried again with a new page. OCFS2 uses this to detect and work around a lock inversion in its aop methods. There should be no change in behaviour for methods that don't return AOP_TRUNCATED_PAGE. WRITEPAGE_ACTIVATE is also prepended with AOP_ for consistency and they are made enums so that kerneldoc can be used to document their semantics. Signed-off-by: Zach Brown --- include/linux/writeback.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 343d883d69c5..64a36ba43b2f 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -59,12 +59,6 @@ struct writeback_control { unsigned for_reclaim:1; /* Invoked from the page allocator */ }; -/* - * ->writepage() return values (make these much larger than a pagesize, in - * case some fs is returning number-of-bytes-written from writepage) - */ -#define WRITEPAGE_ACTIVATE 0x80000 /* IO was not started: activate page */ - /* * fs/fs-writeback.c */ -- cgit v1.2.3 From 22905f775dd6a8b73be99826dcad07ceec00244b Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Wed, 16 Nov 2005 15:07:01 -0800 Subject: identify multipage ->writepages() calls NFS needs to be able to distinguish between single-page ->writepage() calls and multipage ->writepages() calls. For the single-page writepage calls NFS can kick off the I/O within the context of ->writepage(). For multipage ->writepages calls, nfs_writepage() will leave the I/O pending and nfs_writepages() will kick off the I/O when it all has been queued up within NFS. Cc: Trond Myklebust Signed-off-by: Andrew Morton Signed-off-by: Trond Myklebust --- include/linux/writeback.h | 9 +++++---- mm/page-writeback.c | 10 ++++++++-- 2 files changed, 13 insertions(+), 6 deletions(-) (limited to 'include/linux/writeback.h') diff --git a/include/linux/writeback.h b/include/linux/writeback.h index 64a36ba43b2f..b096159086e8 100644 --- a/include/linux/writeback.h +++ b/include/linux/writeback.h @@ -53,10 +53,11 @@ struct writeback_control { loff_t start; loff_t end; - unsigned nonblocking:1; /* Don't get stuck on request queues */ - unsigned encountered_congestion:1; /* An output: a queue is full */ - unsigned for_kupdate:1; /* A kupdate writeback */ - unsigned for_reclaim:1; /* Invoked from the page allocator */ + unsigned nonblocking:1; /* Don't get stuck on request queues */ + unsigned encountered_congestion:1; /* An output: a queue is full */ + unsigned for_kupdate:1; /* A kupdate writeback */ + unsigned for_reclaim:1; /* Invoked from the page allocator */ + unsigned for_writepages:1; /* This is a writepages() call */ }; /* diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0166ea15c9ee..5240e426c1f7 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -550,11 +550,17 @@ void __init page_writeback_init(void) int do_writepages(struct address_space *mapping, struct writeback_control *wbc) { + int ret; + if (wbc->nr_to_write <= 0) return 0; + wbc->for_writepages = 1; if (mapping->a_ops->writepages) - return mapping->a_ops->writepages(mapping, wbc); - return generic_writepages(mapping, wbc); + ret = mapping->a_ops->writepages(mapping, wbc); + else + ret = generic_writepages(mapping, wbc); + wbc->for_writepages = 0; + return ret; } /** -- cgit v1.2.3