From bf6d63ba4c2a2f67396ca1df51b9c10e854be9ac Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@infradead.org>
Date: Wed, 28 Apr 2010 12:28:59 +0000
Subject: [PATCH] --- yaml --- r: 195822 b: refs/heads/master c:
 2b8f12b7e438fa6ba4a0f8f861871be0beb3a3e6 h: refs/heads/master v: v3

---
 [refs]                            |  2 +-
 trunk/fs/xfs/linux-2.6/xfs_aops.c | 25 ++++++++++++++++---------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/[refs] b/[refs]
index b84f3d170b4e..d33d440e3015 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 558e6891693f4c383c51c7343a88dea174eadacf
+refs/heads/master: 2b8f12b7e438fa6ba4a0f8f861871be0beb3a3e6
diff --git a/trunk/fs/xfs/linux-2.6/xfs_aops.c b/trunk/fs/xfs/linux-2.6/xfs_aops.c
index 6feecd279470..1d51bdde5748 100644
--- a/trunk/fs/xfs/linux-2.6/xfs_aops.c
+++ b/trunk/fs/xfs/linux-2.6/xfs_aops.c
@@ -1536,16 +1536,23 @@ __xfs_get_blocks(
 		}
 	}
 
+	/*
+	 * If this is O_DIRECT or the mpage code calling tell them how large
+	 * the mapping is, so that we can avoid repeated get_blocks calls.
+	 */
 	if (direct || size > (1 << inode->i_blkbits)) {
-		struct xfs_mount	*mp = XFS_I(inode)->i_mount;
-		xfs_off_t		iomap_offset = XFS_FSB_TO_B(mp, imap.br_startoff);
-		xfs_off_t		iomap_delta = offset - iomap_offset;
-		xfs_off_t		iomap_bsize = XFS_FSB_TO_B(mp, imap.br_blockcount);
-
-		ASSERT(iomap_bsize - iomap_delta > 0);
-		offset = min_t(xfs_off_t,
-				iomap_bsize - iomap_delta, size);
-		bh_result->b_size = (ssize_t)min_t(xfs_off_t, LONG_MAX, offset);
+		xfs_off_t		mapping_size;
+
+		mapping_size = imap.br_startoff + imap.br_blockcount - iblock;
+		mapping_size <<= inode->i_blkbits;
+
+		ASSERT(mapping_size > 0);
+		if (mapping_size > size)
+			mapping_size = size;
+		if (mapping_size > LONG_MAX)
+			mapping_size = LONG_MAX;
+
+		bh_result->b_size = mapping_size;
 	}
 
 	return 0;