pnfsblock: fix partial page buffer wirte
If applications use flock to protect its write range, generic NFS
will not do read-modify-write cycle at page cache level. Therefore
LD should know how to handle non-sector aligned writes. Otherwise
there will be data corruption.
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Peng Tao <tao.peng@emc.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/blocklayout/blocklayout.h b/fs/nfs/blocklayout/blocklayout.h
index 0335069..39bb51a 100644
--- a/fs/nfs/blocklayout/blocklayout.h
+++ b/fs/nfs/blocklayout/blocklayout.h
@@ -41,6 +41,7 @@
#define PAGE_CACHE_SECTORS (PAGE_CACHE_SIZE >> SECTOR_SHIFT)
#define PAGE_CACHE_SECTOR_SHIFT (PAGE_CACHE_SHIFT - SECTOR_SHIFT)
+#define SECTOR_SIZE (1 << SECTOR_SHIFT)
struct block_mount_id {
spinlock_t bm_lock; /* protects list */