[PATCH v7 02/12] iomap: Mark newly allocated buffer heads as new

From: Andreas Gruenbacher <agruenba@redhat.com>
To: cluster-devel@redhat.com, Christoph Hellwig <hch@lst.de>
Cc: linux-fsdevel@vger.kernel.org, Andreas Gruenbacher <agruenba@redhat.com>
Subject: [PATCH v7 02/12] iomap: Mark newly allocated buffer heads as new
Date: Mon,  4 Jun 2018 14:37:19 +0200	[thread overview]
Message-ID: <20180604123729.23414-3-agruenba@redhat.com> (raw)
In-Reply-To: <20180604123729.23414-1-agruenba@redhat.com>

In iomap_to_bh, not only mark buffer heads in IOMAP_UNWRITTEN maps as
new, but also buffer heads in IOMAP_MAPPED maps with the IOMAP_F_NEW
flag set.  This will be used by filesystems like gfs2, which allocate
blocks in iomap->begin.

Minor corrections to the comment for IOMAP_UNWRITTEN maps.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 fs/buffer.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index 249b83fafe48..0d29bb28b404 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1900,15 +1900,16 @@ iomap_to_bh(struct inode *inode, sector_t block, struct buffer_head *bh,
 		break;
 	case IOMAP_UNWRITTEN:
 		/*
-		 * For unwritten regions, we always need to ensure that
-		 * sub-block writes cause the regions in the block we are not
-		 * writing to are zeroed. Set the buffer as new to ensure this.
+		 * For unwritten regions, we always need to ensure that regions
+		 * in the block we are not writing to are zeroed. Mark the
+		 * buffer as new to ensure this.
 		 */
 		set_buffer_new(bh);
 		set_buffer_unwritten(bh);
 		/* FALLTHRU */
 	case IOMAP_MAPPED:
-		if (offset >= i_size_read(inode))
+		if ((iomap->flags & IOMAP_F_NEW) ||
+		    offset >= i_size_read(inode))
 			set_buffer_new(bh);
 		bh->b_blocknr = (iomap->addr + offset - iomap->offset) >>
 				inode->i_blkbits;
-- 
2.17.0
