[PATCH] filemap_getpage can block when MAP_NONBLOCK specified
commitd345734267dbec642f4e34a9d392d2fd85b5fa9b
authorJeff Moyer <jmoyer@redhat.com>
Sat, 16 Apr 2005 22:24:05 +0000 (16 15:24 -0700)
committerLinus Torvalds <torvalds@ppc970.osdl.org>
Sat, 16 Apr 2005 22:24:05 +0000 (16 15:24 -0700)
tree9a74f4b8292a696620f95933171ac5ddff970ef9
parent41aac24f8fb5a21ff3d0f6f56f85fad3cf0e88a9
[PATCH] filemap_getpage can block when MAP_NONBLOCK specified

We will return NULL from filemap_getpage when a page does not exist in the
page cache and MAP_NONBLOCK is specified, here:

page = find_get_page(mapping, pgoff);
if (!page) {
if (nonblock)
return NULL;
goto no_cached_page;
}

But we forget to do so when the page in the cache is not uptodate.  The
following could result in a blocking call:

/*
 * Ok, found a page in the page cache, now we need to check
 * that it's up-to-date.
 */
if (!PageUptodate(page))
goto page_not_uptodate;

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
mm/filemap.c