Re: [MINI-OS PATCH v2 1/2] 9pfs: add fstat file operation hook

[Samuel Thibault <samuel.thibault@ens-lyon.org>]

Jürgen Groß, le dim. 23 mars 2025 15:57:16 +0100, a ecrit:
> On 23.03.25 01:01, Samuel Thibault wrote:
> > Juergen Gross, le ven. 21 mars 2025 10:31:44 +0100, a ecrit:
> > > Add a file operations fstat hook to the 9pfs frontend.
> > > 
> > > Signed-off-by: Juergen Gross <jgross@suse.com>
> > > Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
> > > ---
> > > V2:
> > > - or file access mode into st_mode (Jason Andryuk)
> > > ---
> > >   9pfront.c | 29 +++++++++++++++++++++++++++++
> > >   1 file changed, 29 insertions(+)
> > > 
> > > diff --git a/9pfront.c b/9pfront.c
> > > index 1741d600..7257a07e 100644
> > > --- a/9pfront.c
> > > +++ b/9pfront.c
> > > @@ -85,6 +85,8 @@ struct file_9pfs {
> > >   #define P9_QID_SIZE    13
> > > +#define QID_TYPE_DIR   0x80     /* Applies to qid[0]. */
> > > +
> > >   struct p9_header {
> > >       uint32_t size;
> > >       uint8_t cmd;
> > > @@ -950,6 +952,32 @@ static int write_9pfs(struct file *file, const void *buf, size_t nbytes)
> > >       return ret;
> > >   }
> > > +static int fstat_9pfs(struct file *file, struct stat *buf)
> > > +{
> > > +    struct file_9pfs *f9pfs = file->filedata;
> > > +    struct p9_stat stat;
> > > +    int ret;
> > > +
> > > +    ret = p9_stat(f9pfs->dev, f9pfs->fid, &stat);
> > > +    if ( ret )
> > > +    {
> > > +        errno = EIO;
> > > +        return -1;
> > > +    }
> > > +
> > > +    buf->st_mode = (stat.qid[0] == QID_TYPE_DIR) ? S_IFDIR : S_IFREG;
> > > +    buf->st_mode |= stat.mode & 0777;
> > > +    buf->st_atime = stat.atime;
> > > +    buf->st_mtime = stat.mtime;
> > 
> > Should we perhaps also fill st_ctime? Leaving it at 0 could surprise
> > other software layers.
> 
> I can set it to the same value as st_mtime.

That'd be preferrable, yes.

With that,

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

Thanks!
Samuel