linux-kernel - Re: [PATCH 02/10] cifs: honor AT_STATX_DONT

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Date:   Thu, 21 Sep 2017 13:14:07 -0500
From:   Steve French <smfrench@...il.com>
To:     Miklos Szeredi <mszeredi@...hat.com>
Cc:     linux-fsdevel <linux-fsdevel@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        Al Viro <viro@...iv.linux.org.uk>,
        David Howells <dhowells@...hat.com>,
        Steve French <sfrench@...ba.org>
Subject: Re: [PATCH 02/10] cifs: honor AT_STATX_DONT_SYNC

Do you have any sample program/code to query with this flag?

On Wed, Sep 20, 2017 at 3:39 AM, Miklos Szeredi <mszeredi@...hat.com> wrote:
> The description of this flag says "Don't sync attributes with the server".
> In other words: always use the attributes cached in the kernel and don't
> send network or local messages to refresh the attributes.
>
> Signed-off-by: Miklos Szeredi <mszeredi@...hat.com>
> Cc: Steve French <sfrench@...ba.org>
> ---
>  fs/cifs/inode.c | 30 ++++++++++++++++--------------
>  1 file changed, 16 insertions(+), 14 deletions(-)
>
> diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
> index a8693632235f..982ba2e4f549 100644
> --- a/fs/cifs/inode.c
> +++ b/fs/cifs/inode.c
> @@ -2003,22 +2003,24 @@ int cifs_getattr(const struct path *path, struct kstat *stat,
>         struct inode *inode = d_inode(dentry);
>         int rc;
>
> -       /*
> -        * We need to be sure that all dirty pages are written and the server
> -        * has actual ctime, mtime and file length.
> -        */
> -       if (!CIFS_CACHE_READ(CIFS_I(inode)) && inode->i_mapping &&
> -           inode->i_mapping->nrpages != 0) {
> -               rc = filemap_fdatawait(inode->i_mapping);
> -               if (rc) {
> -                       mapping_set_error(inode->i_mapping, rc);
> -                       return rc;
> +       if (!(flags & AT_STATX_DONT_SYNC)) {
> +               /*
> +                * We need to be sure that all dirty pages are written and the
> +                * server has actual ctime, mtime and file length.
> +                */
> +               if (!CIFS_CACHE_READ(CIFS_I(inode)) && inode->i_mapping &&
> +                   inode->i_mapping->nrpages != 0) {
> +                       rc = filemap_fdatawait(inode->i_mapping);
> +                       if (rc) {
> +                               mapping_set_error(inode->i_mapping, rc);
> +                               return rc;
> +                       }
>                 }
> -       }
>
> -       rc = cifs_revalidate_dentry_attr(dentry);
> -       if (rc)
> -               return rc;
> +               rc = cifs_revalidate_dentry_attr(dentry);
> +               if (rc)
> +                       return rc;
> +       }
>
>         generic_fillattr(inode, stat);
>         stat->blksize = CIFS_MAX_MSGSIZE;
> --
> 2.5.5
>



-- 
Thanks,

Steve