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 <trond.myklebust@fys.uio.no>
 Signed-off-by: Andrew Morton <akpm@osdl.org>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Andrew Morton 2005-11-16 15:07:01 -08:00 committed by Trond Myklebust
parent d99cf9d679
commit 22905f775d
2 changed files with 13 additions and 6 deletions

View File

@ -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 */
};
/*

View File

@ -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;
}
/**