[Devel] [PATCH RHEL7 COMMIT] fuse: no mtime flush on fdatasync

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-327.36.1.vz7.20.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-327.36.1.vz7.20.9
------>
commit 2b39263eeee33196c731257c173f7be35d4bd8a4
Author: Maxim Patlasov <mpatlasov at virtuozzo.com>
Date:   Fri Dec 2 18:34:57 2016 +0400

    fuse: no mtime flush on fdatasync
    
    fuse_fsync_common() may skip fuse_flush_mtime() if datasync=1 because
    mtime is pure metadata and the content of file doesn't depend on it.
    
    https://jira.sw.ru/browse/PSBM-55919
    
    Signed-off-by: Maxim Patlasov <mpatlasov at virtuozzo.com>
    Acked-by: Dmitry Monakhov <dmonakhov at openvz.org>
---
 fs/fuse/file.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index d11125f..52bca91 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -691,8 +691,8 @@ int fuse_fsync_common(struct file *file, loff_t start, loff_t end,
 	if (err)
 		goto out;
 
-	if (test_bit(FUSE_I_MTIME_UPDATED,
-		     &get_fuse_inode(inode)->state)) {
+	if (!datasync && test_bit(FUSE_I_MTIME_UPDATED,
+				  &get_fuse_inode(inode)->state)) {
 		err = fuse_flush_mtime(file, false);
 		if (err)
 			goto out;