ext4: use current_time() for inode timestamps

CURRENT_TIME_SEC and CURRENT_TIME are not y2038 safe.
current_time() will be transitioned to be y2038 safe
along with vfs.

current_time() returns timestamps according to the
granularities set in the super_block.
The granularity check in ext4_current_time() to call
current_time() or CURRENT_TIME_SEC is not required.
Use current_time() directly to obtain timestamps
unconditionally, and remove ext4_current_time().

Quota files are assumed to be on the same filesystem.
Hence, use current_time() for these files as well.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 79f46f4..e821ee2 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4039,7 +4039,7 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
 	if (IS_SYNC(inode))
 		ext4_handle_sync(handle);
 
-	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	inode->i_mtime = inode->i_ctime = current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 out_stop:
 	ext4_journal_stop(handle);
@@ -4195,7 +4195,7 @@ int ext4_truncate(struct inode *inode)
 	if (inode->i_nlink)
 		ext4_orphan_del(handle, inode);
 
-	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	inode->i_mtime = inode->i_ctime = current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
 	ext4_journal_stop(handle);
 
@@ -5170,7 +5170,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 			 * update c/mtime in shrink case below
 			 */
 			if (!shrink) {
-				inode->i_mtime = ext4_current_time(inode);
+				inode->i_mtime = current_time(inode);
 				inode->i_ctime = inode->i_mtime;
 			}
 			down_write(&EXT4_I(inode)->i_data_sem);