From: Miklos Szeredi <mszeredi@xxxxxxxxxx>
commit 473441720c8616dfaf4451f9c7ea14f0eb5e5d65 upstream.
Checking buf->flags should be done before the pipe_buf_release() is called
on the pipe buffer, since releasing the buffer might modify the flags.
This is exactly what page_cache_pipe_buf_release() does, and which results
in the same VM_BUG_ON_PAGE(PageLRU(page)) that the original patch was
trying to fix.
Reported-by: Justin Forbes <jmforbes@xxxxxxxxxxx>
Fixes: 712a951025c0 ("fuse: fix page stealing")
Cc: <stable@xxxxxxxxxxxxxxx> # v2.6.35
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/fuse/dev.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -922,6 +922,11 @@ static int fuse_try_move_page(struct fus
return err;
}
+ page_cache_get(newpage);
+
+ if (!(buf->flags & PIPE_BUF_FLAG_LRU))
+ lru_cache_add_file(newpage);
+
/*
* Release while we have extra ref on stolen page. Otherwise
* anon_pipe_buf_release() might think the page can be reused.
@@ -929,11 +934,6 @@ static int fuse_try_move_page(struct fus
buf->ops->release(cs->pipe, buf);
buf->ops = NULL;
- page_cache_get(newpage);
-
- if (!(buf->flags & PIPE_BUF_FLAG_LRU))
- lru_cache_add_file(newpage);
-
err = 0;
spin_lock(&cs->req->waitq.lock);
if (test_bit(FR_ABORTED, &cs->req->flags))
