mm: fix infinite loop in filemap_fault
commit3ef0f720e47e895b613b0305eb0a483e3ec11f23
authorMiklos Szeredi <mszeredi@suse.cz>
Wed, 14 May 2008 23:05:37 +0000 (14 16:05 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 15 May 2008 02:11:13 +0000 (14 19:11 -0700)
treee696a950d76c90199661515e1068fc00102a15bf
parent3b73a223661ed137c5d3d2635f954382e94f5a43
mm: fix infinite loop in filemap_fault

filemap_fault will go into an infinite loop if ->readpage() fails
asynchronously.

AFAICS the bug was introduced by this commit, which removed the wait after the
final readpage:

   commit d00806b183152af6d24f46f0c33f14162ca1262a
   Author: Nick Piggin <npiggin@suse.de>
   Date:   Thu Jul 19 01:46:57 2007 -0700

       mm: fix fault vs invalidate race for linear mappings

Fix by reintroducing the wait_on_page_locked() after ->readpage() to make sure
the page is up-to-date before jumping back to the beginning of the function.

I've noticed this while testing nfs exporting on fuse.  The patch
fixes it.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/filemap.c