From: Dave Kleikamp <dave.kleikamp@oracle.com>
Date: Thu, 12 Apr 2012 21:44:41 +0000 (-0500)
Subject: directio: account for extra page IOs for unaligned request
X-Git-Tag: v2.6.39-400.9.0~426^2~17^2
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=c795b2961e57da8db9c5bb912488ec973802bf44;p=users%2Fjedix%2Flinux-maple.git

directio: account for extra page IOs for unaligned request

sdio_init() initializes pages_in_io to 2 for an unaligned directio request
in order that a zero page may be written to the first and last block.
However, __blockdev_direct_IO_bvec was setting pages_in_io to the number
of pages in the request rather than adding them to the original value.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
---

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 65ff39f39519..3c138051e585 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -1400,7 +1400,7 @@ __blockdev_direct_IO_bvec(int rw, struct kiocb *iocb, struct inode *inode,
 
 	sdio_init(&sdio, inode, offset, blkbits, get_block, submit_io);
 
-	sdio.pages_in_io = bvec_len;
+	sdio.pages_in_io += bvec_len;
 
 	for (i = 0; i < bvec_len; i++) {
 		sdio.size += bvec[i].bv_len;