On Thu, Apr 12, 2018 at 05:07:55PM +0200, Miklos Szeredi wrote:
> Copy up mtime and ctime to overlay inode after times in real object are
> modified. Be careful not to dirty cachelines when not necessary.
>
> This is in preparation for moving overlay functionality out of the VFS.
>
> This patch shouldn't have any observable effect.
So there are bunch of operations which will change inode ctime. I had
missed this in my metadata only copy up patch series and that would broken
atime updates in some cases.
Vivek
>
> Signed-off-by: Miklos Szeredi <mszer...@redhat.com>
> ---
> fs/overlayfs/dir.c | 5 +++++
> fs/overlayfs/inode.c | 1 +
> fs/overlayfs/overlayfs.h | 7 +++++++
> fs/overlayfs/util.c | 19 +++++++++++++++++++
> 4 files changed, 32 insertions(+)
>
> diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
> index 839709c7803a..cd0fa2363723 100644
> --- a/fs/overlayfs/dir.c
> +++ b/fs/overlayfs/dir.c
> @@ -507,6 +507,7 @@ static int ovl_create_or_link(struct dentry *dentry,
> struct inode *inode,
> else
> err = ovl_create_over_whiteout(dentry, inode, attr,
> hardlink);
> + ovl_copytimes_with_parent(dentry);
> }
> out_revert_creds:
> revert_creds(old_cred);
> @@ -768,6 +769,7 @@ static int ovl_do_remove(struct dentry *dentry, bool
> is_dir)
> drop_nlink(dentry->d_inode);
> }
> ovl_nlink_end(dentry, locked);
> + ovl_copytimes_with_parent(dentry);
> out_drop_write:
> ovl_drop_write(dentry);
> out:
> @@ -1079,6 +1081,9 @@ static int ovl_rename(struct inode *olddir, struct
> dentry *old,
> ovl_dentry_version_inc(new->d_parent, ovl_type_origin(old) ||
> (d_inode(new) && ovl_type_origin(new)));
>
> + ovl_copytimes_with_parent(old);
> + ovl_copytimes_with_parent(new);
> +
> out_dput:
> dput(newdentry);
> out_dput_old:
> diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
> index 6e3815fb006b..33635106c5f7 100644
> --- a/fs/overlayfs/inode.c
> +++ b/fs/overlayfs/inode.c
> @@ -303,6 +303,7 @@ int ovl_xattr_set(struct dentry *dentry, struct inode
> *inode, const char *name,
> err = vfs_removexattr(realdentry, name);
> }
> revert_creds(old_cred);
> + ovl_copytimes(d_inode(dentry));
>
> out_drop_write:
> ovl_drop_write(dentry);
> diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
> index e0b7de799f6b..eef720ef0f07 100644
> --- a/fs/overlayfs/overlayfs.h
> +++ b/fs/overlayfs/overlayfs.h
> @@ -258,6 +258,13 @@ bool ovl_need_index(struct dentry *dentry);
> int ovl_nlink_start(struct dentry *dentry, bool *locked);
> void ovl_nlink_end(struct dentry *dentry, bool locked);
> int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
> +void ovl_copytimes(struct inode *inode);
> +
> +static inline void ovl_copytimes_with_parent(struct dentry *dentry)
> +{
> + ovl_copytimes(d_inode(dentry));
> + ovl_copytimes(d_inode(dentry->d_parent));
> +}
>
> static inline bool ovl_is_impuredir(struct dentry *dentry)
> {
> diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
> index 6f1078028c66..11e62e70733a 100644
> --- a/fs/overlayfs/util.c
> +++ b/fs/overlayfs/util.c
> @@ -675,3 +675,22 @@ int ovl_lock_rename_workdir(struct dentry *workdir,
> struct dentry *upperdir)
> pr_err("overlayfs: failed to lock workdir+upperdir\n");
> return -EIO;
> }
> +
> +void ovl_copytimes(struct inode *inode)
> +{
> + struct inode *upperinode;
> +
> + if (!inode)
> + return;
> +
> + upperinode = ovl_inode_upper(inode);
> +
> + if (!upperinode)
> + return;
> +
> + if ((!timespec_equal(&inode->i_mtime, &upperinode->i_mtime) ||
> + !timespec_equal(&inode->i_ctime, &upperinode->i_ctime))) {
> + inode->i_mtime = upperinode->i_mtime;
> + inode->i_ctime = upperinode->i_ctime;
> + }
> +}
> --
> 2.14.3
>
> --
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