[RFC PATCH 3/6] Btrfs: add support for setting btime

[Omar Sandoval]

From: Omar Sandoval <osan...@fb.com>

The Btrfs inode format has always included btime (under the name otime),
so setting it is trivial.

Signed-off-by: Omar Sandoval <osan...@fb.com>
---
 fs/btrfs/inode.c | 2 ++
 fs/btrfs/super.c | 4 ++--
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5c349667c761..49ad777d8057 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5153,6 +5153,8 @@ static int btrfs_setattr(struct dentry *dentry, struct 
iattr *attr)
 
        if (attr->ia_valid) {
                setattr_copy(inode, attr);
+               if (attr->ia_valid & ATTR_BTIME)
+                       BTRFS_I(inode)->i_otime = attr->ia_btime;
                inode_inc_iversion(inode);
                err = btrfs_dirty_inode(inode);
 
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 0a3f122dd61f..2af368cad2aa 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2140,7 +2140,7 @@ static struct file_system_type btrfs_fs_type = {
        .name           = "btrfs",
        .mount          = btrfs_mount,
        .kill_sb        = btrfs_kill_super,
-       .fs_flags       = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
+       .fs_flags       = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_HAS_BTIME,
 };
 
 static struct file_system_type btrfs_root_fs_type = {
@@ -2148,7 +2148,7 @@ static struct file_system_type btrfs_root_fs_type = {
        .name           = "btrfs",
        .mount          = btrfs_mount_root,
        .kill_sb        = btrfs_kill_super,
-       .fs_flags       = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA,
+       .fs_flags       = FS_REQUIRES_DEV | FS_BINARY_MOUNTDATA | FS_HAS_BTIME,
 };
 
 MODULE_ALIAS_FS("btrfs");
-- 
2.20.1