[PATCH 02/10] fuse2fs: skip permission checking on utimens when iomap is enabled

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Darrick J. Wong <djwong@xxxxxxxxxx>

When iomap is enabled, the kernel is in charge of enforcing permissions
checks on timestamp updates for files.  We needn't do that in userspace
anymore.

Signed-off-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
---
 misc/fuse2fs.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)


diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index f9151ae6acb4e5..5d75cffa8f6bca 100644
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -4334,11 +4334,12 @@ static int op_utimens(const char *path, const struct timespec ctv[2]
 
 	/*
 	 * ext4 allows timestamp updates of append-only files but only if we're
-	 * setting to current time
+	 * setting to current time.  If iomap is enabled, the kernel does the
+	 * permission checking for timestamp updates and we can skip the check.
 	 */
 	if (ctv[0].tv_nsec == UTIME_NOW && ctv[1].tv_nsec == UTIME_NOW)
 		access |= A_OK;
-	ret = check_inum_access(ff, ino, access);
+	ret = fuse2fs_iomap_enabled(ff) ? 0 : check_inum_access(ff, ino, access);
 	if (ret)
 		goto out;