Re: [PATCH 5/7] procfs: generalize the translator linkage code

[Samuel Thibault]

Justus Winter, le Mon 22 Sep 2014 11:38:42 +0200, a écrit :
> Generalize the translator linkage code previously introduced for the
> `mounts' node.

Ack.

> * procfs/rootdir.c (struct procfs_translated_node_ops): New
> specialized node operations structure for translated nodes.
> (rootdir_mounts_make_node): Generalize and rename to
> rootdir_make_translated_node.  Also, pass the entry_hook to
> procfs_make_node so that...
> (rootdir_mounts_get_translator): ... can be generalized to
> rootdir_translated_node_get_translator and read the argz vector from
> the hooked structure.
> (ROOTDIR_DEFINE_TRANSLATED_NODE): New convenience macro to define
> translated nodes.
> (rootdir_entries): Use the new code for the `mounts' node.
> ---
>  procfs/rootdir.c | 62 
> ++++++++++++++++++++++++++++++++++++++------------------
>  1 file changed, 42 insertions(+), 20 deletions(-)
> 
> diff --git a/procfs/rootdir.c b/procfs/rootdir.c
> index 81e36f7..a04fb3e 100644
> --- a/procfs/rootdir.c
> +++ b/procfs/rootdir.c
> @@ -409,17 +409,29 @@ rootdir_gc_fakeself (void *hook, char **contents, 
> ssize_t *contents_len)
>  }
>  
>  static struct node *rootdir_mounts_node;
> -static pthread_spinlock_t rootdir_mounts_node_lock =
> +
> +/* Translator linkage.  */
> +static pthread_spinlock_t rootdir_translated_node_lock =
>    PTHREAD_SPINLOCK_INITIALIZER;
>  
> +struct procfs_translated_node_ops
> +{
> +  struct procfs_node_ops node_ops;
> +
> +  struct node **npp;
> +  char *argz;
> +  size_t argz_len;
> +};
> +
>  static struct node *
> -rootdir_mounts_make_node (void *dir_hook, const void *entry_hook)
> +rootdir_make_translated_node (void *dir_hook, const void *entry_hook)
>  {
> +  const struct procfs_translated_node_ops *ops = entry_hook;
>    struct node *np, *prev;
>  
> -  pthread_spin_lock (&rootdir_mounts_node_lock);
> -  np = rootdir_mounts_node;
> -  pthread_spin_unlock (&rootdir_mounts_node_lock);
> +  pthread_spin_lock (&rootdir_translated_node_lock);
> +  np = *ops->npp;
> +  pthread_spin_unlock (&rootdir_translated_node_lock);
>  
>    if (np != NULL)
>      {
> @@ -427,18 +439,18 @@ rootdir_mounts_make_node (void *dir_hook, const void 
> *entry_hook)
>        return np;
>      }
>  
> -  np = procfs_make_node (entry_hook, dir_hook);
> +  np = procfs_make_node (entry_hook, entry_hook);
>    if (np == NULL)
>      return NULL;
>  
>    procfs_node_chtype (np, S_IFREG | S_IPTRANS);
>    procfs_node_chmod (np, 0444);
>  
> -  pthread_spin_lock (&rootdir_mounts_node_lock);
> -  prev = rootdir_mounts_node;
> -  if (rootdir_mounts_node == NULL)
> -    rootdir_mounts_node = np;
> -  pthread_spin_unlock (&rootdir_mounts_node_lock);
> +  pthread_spin_lock (&rootdir_translated_node_lock);
> +  prev = *ops->npp;
> +  if (*ops->npp == NULL)
> +    *ops->npp = np;
> +  pthread_spin_unlock (&rootdir_translated_node_lock);
>  
>    if (prev != NULL)
>      {
> @@ -450,19 +462,30 @@ rootdir_mounts_make_node (void *dir_hook, const void 
> *entry_hook)
>  }
>  
>  static error_t
> -rootdir_mounts_get_translator (void *hook, char **argz, size_t *argz_len)
> +rootdir_translated_node_get_translator (void *hook, char **argz,
> +                                     size_t *argz_len)
>  {
> -  static const char const mtab_argz[] = _HURD_MTAB "\0/";
> +  const struct procfs_translated_node_ops *ops = hook;
>  
> -  *argz = malloc (sizeof mtab_argz);
> +  *argz = malloc (ops->argz_len);
>    if (! *argz)
>      return ENOMEM;
>  
> -  memcpy (*argz, mtab_argz, sizeof mtab_argz);
> -  *argz_len = sizeof mtab_argz;
> +  memcpy (*argz, ops->argz, ops->argz_len);
> +  *argz_len = ops->argz_len;
>    return 0;
>  }
>  
> +#define ROOTDIR_DEFINE_TRANSLATED_NODE(NPP, ARGZ)              \
> +  &(struct procfs_translated_node_ops) {                       \
> +    .node_ops = {                                              \
> +      .get_translator = rootdir_translated_node_get_translator,        \
> +    },                                                                 \
> +    .npp = NPP,                                                        \
> +    .argz = (ARGZ),                                            \
> +    .argz_len = sizeof (ARGZ),                                         \
> +  }
> +
>  static error_t
>  rootdir_gc_slabinfo (void *hook, char **contents, ssize_t *contents_len)
>  {
> @@ -660,11 +683,10 @@ static const struct procfs_dir_entry rootdir_entries[] 
> = {
>    },
>    {
>      .name = "mounts",
> -    .hook = & (struct procfs_node_ops) {
> -      .get_translator = rootdir_mounts_get_translator,
> -    },
> +    .hook = ROOTDIR_DEFINE_TRANSLATED_NODE (&rootdir_mounts_node,
> +                                         _HURD_MTAB "\0/"),
>      .ops = {
> -      .make_node = rootdir_mounts_make_node,
> +      .make_node = rootdir_make_translated_node,
>      }
>    },
>    {
> -- 
> 2.1.0
> 

-- 
Samuel
<g> r: et la marmotte, elle écrit un papier IPDPS