From 8f065d36508f283ee6cbeb05829f032d0b782a16 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Tue, 3 May 2011 11:49:19 +0100 Subject: GFS2: Improve bug trap code in ->releasepage() If the buffer is dirty or pinned, then as well as printing a warning, we should also refuse to release the page in question. Currently this can occur if there is a race between mmap()ed writers and O_DIRECT on the same file. With the addition of ->launder_page() in the future, we should be able to close this gap. Signed-off-by: Steven Whitehouse --- fs/gfs2/aops.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/gfs2/aops.c b/fs/gfs2/aops.c index 0f5c4f9..802ac5e 100644 --- a/fs/gfs2/aops.c +++ b/fs/gfs2/aops.c @@ -1076,8 +1076,8 @@ int gfs2_releasepage(struct page *page, gfp_t gfp_mask) bd = bh->b_private; if (bd && bd->bd_ail) goto cannot_release; - gfs2_assert_warn(sdp, !buffer_pinned(bh)); - gfs2_assert_warn(sdp, !buffer_dirty(bh)); + if (buffer_pinned(bh) || buffer_dirty(bh)) + goto not_possible; bh = bh->b_this_page; } while(bh != head); gfs2_log_unlock(sdp); @@ -1107,6 +1107,10 @@ int gfs2_releasepage(struct page *page, gfp_t gfp_mask) } while (bh != head); return try_to_free_buffers(page); + +not_possible: /* Should never happen */ + WARN_ON(buffer_dirty(bh)); + WARN_ON(buffer_pinned(bh)); cannot_release: gfs2_log_unlock(sdp); return 0; -- cgit v1.1