fs: don't call ->dirty_inode for lazytime timestamp updates

There is no need to call ->dirty_inode for lazytime timestamp updates
(i.e. for __mark_inode_dirty(I_DIRTY_TIME)), since by the definition of
lazytime, filesystems must ignore these updates.  Filesystems only need
to care about the updated timestamps when they expire.

Therefore, only call ->dirty_inode when I_DIRTY_INODE is set.

Based on a patch from Christoph Hellwig:
https://lore.kernel.org/r/20200325122825.1086872-4-hch@lst.de

Link: https://lore.kernel.org/r/20210112190253.64307-6-ebiggers@kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Jan Kara <jack@suse.cz>

fs/ext4/inode.c

@@ -5933,26 +5933,16 @@ out:
  * If the inode is marked synchronous, we don't honour that here - doing
  * so would cause a commit on atime updates, which we don't bother doing.
  * We handle synchronous inodes at the highest possible level.
- *
- * If only the I_DIRTY_TIME flag is set, we can skip everything.  If
- * I_DIRTY_TIME and I_DIRTY_SYNC is set, the only inode fields we need
- * to copy into the on-disk inode structure are the timestamp files.
  */
 void ext4_dirty_inode(struct inode *inode, int flags)
 {
 	handle_t *handle;
 
-	if (flags == I_DIRTY_TIME)
-		return;
 	handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
 	if (IS_ERR(handle))
-		goto out;
+		return;
-
 	ext4_mark_inode_dirty(handle, inode);
-
 	ext4_journal_stop(handle);
-out:
-	return;
 }
 
 int ext4_change_inode_journal_flag(struct inode *inode, int val)

fs/f2fs/super.c

@@ -1196,9 +1196,6 @@ static void f2fs_dirty_inode(struct inode *inode, int flags)
 			inode->i_ino == F2FS_META_INO(sbi))
 		return;
 
-	if (flags == I_DIRTY_TIME)
-		return;
-
 	if (is_inode_flag_set(inode, FI_AUTO_RECOVER))
 		clear_inode_flag(inode, FI_AUTO_RECOVER);
 

fs/fs-writeback.c

@@ -2255,16 +2255,16 @@ void __mark_inode_dirty(struct inode *inode, int flags)
 	 * Don't do this for I_DIRTY_PAGES - that doesn't actually
 	 * dirty the inode itself
 	 */
-	if (flags & (I_DIRTY_INODE | I_DIRTY_TIME)) {
+	if (flags & I_DIRTY_INODE) {
 		trace_writeback_dirty_inode_start(inode, flags);
 
 		if (sb->s_op->dirty_inode)
 			sb->s_op->dirty_inode(inode, flags);
 
 		trace_writeback_dirty_inode(inode, flags);
-	}
+
-	if (flags & I_DIRTY_INODE)
 		flags &= ~I_DIRTY_TIME;
+	}
 	dirtytime = flags & I_DIRTY_TIME;
 
 	/*

fs/gfs2/super.c

@@ -562,8 +562,6 @@ static void gfs2_dirty_inode(struct inode *inode, int flags)
 	int need_endtrans = 0;
 	int ret;
 
-	if (!(flags & I_DIRTY_INODE))
-		return;
 	if (unlikely(gfs2_withdrawn(sdp)))
 		return;
 	if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {