[PATCH AUTOSEL 3.18 66/98] ext4: fix an ext3 collapse range regression in xfstests

[Sasha Levin]

From: Theodore Ts'o <tytso@xxxxxxx>

[ Upstream commit b9576fc3624eb9fc88bec0d0ae883fd78be86239 ]

The xfstests test suite assumes that an attempt to collapse range on
the range (0, 1) will return EOPNOTSUPP if the file system does not
support collapse range.  Commit 280227a75b56: "ext4: move check under
lock scope to close a race" broke this, and this caused xfstests to
fail when run when testing file systems that did not have the extents
feature enabled.

Reported-by: Eric Whitney <enwlinux@xxxxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/ext4/extents.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 6dbfa92bf78a..1e51008e237f 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -5400,6 +5400,14 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
 	loff_t new_size, ioffset;
 	int ret;
 
+	/*
+	 * We need to test this early because xfstests assumes that a
+	 * collapse range of (0, 1) will return EOPNOTSUPP if the file
+	 * system does not support collapse range.
+	 */
+	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+		return -EOPNOTSUPP;
+
 	/* Collapse range works only on fs block size aligned offsets. */
 	if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
 	    len & (EXT4_CLUSTER_SIZE(sb) - 1))
-- 
2.17.1