From: Ross Zwisler <ross.zwisler@linux.intel.com>
Date: Tue, 8 Nov 2016 00:30:58 +0000 (+1100)
Subject: ext4: tell DAX the size of allocation holes
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=547edce3ba234a5161c6e1f4389f4a0d2f8451aa;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

ext4: tell DAX the size of allocation holes

When DAX calls _ext4_get_block() and the file offset points to a hole we
currently don't set bh->b_size.  This is current worked around via
buffer_size_valid() in fs/dax.c.

_ext4_get_block() has the hole size information from ext4_map_blocks(), so
populate bh->b_size so we can remove buffer_size_valid() in a later patch.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <david@fromorbit.com>
---

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 9c064727ed62..3d58b2b477e8 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -767,6 +767,9 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock,
 		ext4_update_bh_state(bh, map.m_flags);
 		bh->b_size = inode->i_sb->s_blocksize * map.m_len;
 		ret = 0;
+	} else if (ret == 0) {
+		/* hole case, need to fill in bh->b_size */
+		bh->b_size = inode->i_sb->s_blocksize * map.m_len;
 	}
 	return ret;
 }