Re: [PATCH 072/104] virtiofsd: passthrough_ll: fix refcounting on remove/rename

[Dr. David Alan Gilbert]

* Misono Tomohiro (address@hidden) wrote:
> > From: Miklos Szeredi <address@hidden>
> > 
> > Signed-off-by: Miklos Szeredi <address@hidden>
> 
> I'm not familiar with qemu convention but shouldn't we put
> at least one line of description like linux kernel?

Miklos: would you like to suggest a better commit message?

> For code itself:
>  Reviewed-by: Misono Tomohiro <address@hidden>

Thanks!

> 
> > ---
> >  tools/virtiofsd/passthrough_ll.c | 50 +++++++++++++++++++++++++++++++-
> >  1 file changed, 49 insertions(+), 1 deletion(-)
> > 
> > diff --git a/tools/virtiofsd/passthrough_ll.c 
> > b/tools/virtiofsd/passthrough_ll.c
> > index 0f33c3c5e9..1b84d4f313 100644
> > --- a/tools/virtiofsd/passthrough_ll.c
> > +++ b/tools/virtiofsd/passthrough_ll.c
> > @@ -1077,17 +1077,42 @@ out_err:
> >      fuse_reply_err(req, saverr);
> >  }
> >  
> > +static struct lo_inode *lookup_name(fuse_req_t req, fuse_ino_t parent,
> > +                                    const char *name)
> > +{
> > +    int res;
> > +    struct stat attr;
> > +
> > +    res = fstatat(lo_fd(req, parent), name, &attr,
> > +                  AT_EMPTY_PATH | AT_SYMLINK_NOFOLLOW);
> > +    if (res == -1) {
> > +        return NULL;
> > +    }
> > +
> > +    return lo_find(lo_data(req), &attr);
> > +}
> > +
> >  static void lo_rmdir(fuse_req_t req, fuse_ino_t parent, const char *name)
> >  {
> >      int res;
> > +    struct lo_inode *inode;
> > +    struct lo_data *lo = lo_data(req);
> > +
> >      if (!is_safe_path_component(name)) {
> >          fuse_reply_err(req, EINVAL);
> >          return;
> >      }
> >  
> > +    inode = lookup_name(req, parent, name);
> > +    if (!inode) {
> > +        fuse_reply_err(req, EIO);
> > +        return;
> > +    }
> > +
> >      res = unlinkat(lo_fd(req, parent), name, AT_REMOVEDIR);
> >  
> >      fuse_reply_err(req, res == -1 ? errno : 0);
> > +    unref_inode_lolocked(lo, inode, 1);
> >  }
> >  
> >  static void lo_rename(fuse_req_t req, fuse_ino_t parent, const char *name,
> > @@ -1095,12 +1120,23 @@ static void lo_rename(fuse_req_t req, fuse_ino_t 
> > parent, const char *name,
> >                        unsigned int flags)
> >  {
> >      int res;
> > +    struct lo_inode *oldinode;
> > +    struct lo_inode *newinode;
> > +    struct lo_data *lo = lo_data(req);
> >  
> >      if (!is_safe_path_component(name) || !is_safe_path_component(newname)) 
> > {
> >          fuse_reply_err(req, EINVAL);
> >          return;
> >      }
> >  
> > +    oldinode = lookup_name(req, parent, name);
> > +    newinode = lookup_name(req, newparent, newname);
> > +
> > +    if (!oldinode) {
> > +        fuse_reply_err(req, EIO);
> > +        goto out;
> > +    }
> > +
> >      if (flags) {
> >  #ifndef SYS_renameat2
> >          fuse_reply_err(req, EINVAL);
> > @@ -1113,26 +1149,38 @@ static void lo_rename(fuse_req_t req, fuse_ino_t 
> > parent, const char *name,
> >              fuse_reply_err(req, res == -1 ? errno : 0);
> >          }
> >  #endif
> > -        return;
> > +        goto out;
> >      }
> >  
> >      res = renameat(lo_fd(req, parent), name, lo_fd(req, newparent), 
> > newname);
> >  
> >      fuse_reply_err(req, res == -1 ? errno : 0);
> > +out:
> > +    unref_inode_lolocked(lo, oldinode, 1);
> > +    unref_inode_lolocked(lo, newinode, 1);
> >  }
> >  
> >  static void lo_unlink(fuse_req_t req, fuse_ino_t parent, const char *name)
> >  {
> >      int res;
> > +    struct lo_inode *inode;
> > +    struct lo_data *lo = lo_data(req);
> >  
> >      if (!is_safe_path_component(name)) {
> >          fuse_reply_err(req, EINVAL);
> >          return;
> >      }
> >  
> > +    inode = lookup_name(req, parent, name);
> > +    if (!inode) {
> > +        fuse_reply_err(req, EIO);
> > +        return;
> > +    }
> > +
> >      res = unlinkat(lo_fd(req, parent), name, 0);
> >  
> >      fuse_reply_err(req, res == -1 ? errno : 0);
> > +    unref_inode_lolocked(lo, inode, 1);
> >  }
> >  
> >  static void unref_inode_lolocked(struct lo_data *lo, struct lo_inode 
> > *inode,
> > -- 
> > 2.23.0
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK