Re: [PATCH v2 05/12] fs: don't call ->dirty_inode for lazytime timestamp updates

Jan Kara
2021-01-11T14:56:04Z

On Fri 08-01-21 23:58:56, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> 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
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

Honza

> ---
> fs/ext4/inode.c | 12 +-----------
> fs/f2fs/super.c | 3 ---
> fs/fs-writeback.c | 6 +++---
> fs/gfs2/super.c | 2 --
> 4 files changed, 4 insertions(+), 19 deletions(-)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 27946882d4ce4..4cc6c7834312f 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -5933,26 +5933,16 @@ int __ext4_mark_inode_dirty(handle_t *handle, struct inode *inode,
> * 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)
> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
> index b4a07fe62d1a5..cc98dc49f4a26 100644
> --- a/fs/f2fs/super.c
> +++ b/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);
>
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index c41cb887eb7d3..b7616bbd55336 100644
> --- a/fs/fs-writeback.c
> +++ b/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;
>
> /*
> diff --git a/fs/gfs2/super.c b/fs/gfs2/super.c
> index 2f56acc41c049..042b94288ff11 100644
> --- a/fs/gfs2/super.c
> +++ b/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)) {
> --
> 2.30.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR