[Bug,16165] Wrong data returned on read after write if file size was changed with ftruncate before

Submitted by bugzilla-daemon@bugzilla.kernel.org on June 18, 2010, 3:30 p.m.

Details

Message ID 201006181530.o5IFUIZh002098@demeter.kernel.org
State New
Headers show

Commit Message

bugzilla-daemon@bugzilla.kernel.org June 18, 2010, 3:30 p.m.
https://bugzilla.kernel.org/show_bug.cgi?id=16165





--- Comment #12 from Eric Sandeen <sandeen@redhat.com>  2010-06-18 15:30:13 ---
Can those who can reproduce this test this patch from mingming?

When unaligned DIO writes, skip zero out the block if the buffer is marked
unwritten. That means there is an asynconous direct IO (append or fill the
hole)
still pending.

Signed-off-by: Mingming Cao <cmm@us.ibm.com>
---
 fs/direct-io.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Patch hide | download patch | download mbox

Index: linux-git/fs/direct-io.c
===================================================================
--- linux-git.orig/fs/direct-io.c    2010-05-07 15:42:22.855033403 -0700
+++ linux-git/fs/direct-io.c    2010-05-07 15:44:17.695007770 -0700
@@ -740,7 +740,8 @@ 
     struct page *page;

     dio->start_zero_done = 1;
-    if (!dio->blkfactor || !buffer_new(&dio->map_bh))
+    if (!dio->blkfactor || !buffer_new(&dio->map_bh)
+        || buffer_unwritten(&dio->map_bh))
         return;

     dio_blocks_per_fs_block = 1 << dio->blkfactor;