Re: [MINIOS PATCH v3 03/12] use alloc_file_type() and get_file_from_fd() in xs

[Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>]

Juergen Gross, le dim. 16 janv. 2022 09:33:19 +0100, a ecrit:
> Allocate the needed file type via alloc_file_type().
> 
> Instead of directly accessing the files[] array use get_file_from_fd().
> 
> Signed-off-by: Juergen Gross <jgross@xxxxxxxx>

Reviewed-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>

> ---
> V3:
> - switch to struct file * parameter for callbacks
> - use __attribute__((constructor))
> ---
>  include/lib.h   |  3 +--
>  lib/sys.c       | 18 --------------
>  lib/xs.c        | 65 +++++++++++++++++++++++++++++++++++++------------
>  xenbus/xenbus.c |  1 +
>  4 files changed, 52 insertions(+), 35 deletions(-)
> 
> diff --git a/include/lib.h b/include/lib.h
> index 5838b0d4..c5e47786 100644
> --- a/include/lib.h
> +++ b/include/lib.h
> @@ -169,8 +169,7 @@ extern struct wait_queue_head event_queue;
>  #define FTYPE_BLK        9
>  #define FTYPE_TPMFRONT  10
>  #define FTYPE_TPM_TIS   11
> -#define FTYPE_XENBUS    12
> -#define FTYPE_N         13
> +#define FTYPE_N         12
>  #define FTYPE_SPARE     16
>  
>  struct file {
> diff --git a/lib/sys.c b/lib/sys.c
> index 6ba26294..53870aa4 100644
> --- a/lib/sys.c
> +++ b/lib/sys.c
> @@ -523,11 +523,6 @@ int close(int fd)
>      switch (file->type) {
>          default:
>              break;
> -#ifdef CONFIG_LIBXS
> -     case FTYPE_XENBUS:
> -            xs_daemon_close((void*)(intptr_t) fd);
> -            break;
> -#endif
>  #ifdef HAVE_LWIP
>       case FTYPE_SOCKET:
>              res = lwip_close(files[fd].fd);
> @@ -759,7 +754,6 @@ int closedir(DIR *dir)
>  static const char *const file_types[] = {
>      [FTYPE_NONE]    = "none",
>      [FTYPE_CONSOLE] = "console",
> -    [FTYPE_XENBUS]  = "xenbus",
>      [FTYPE_SOCKET]  = "socket",
>      [FTYPE_TAP]     = "net",
>      [FTYPE_BLK]     = "blk",
> @@ -947,18 +941,6 @@ static int select_poll(int nfds, fd_set *readfds, fd_set 
> *writefds, fd_set *exce
>                  n++;
>           FD_CLR(i, exceptfds);
>           break;
> -#ifdef CONFIG_LIBXS
> -     case FTYPE_XENBUS:
> -         if (FD_ISSET(i, readfds)) {
> -                if (files[i].dev)
> -                 n++;
> -             else
> -                 FD_CLR(i, readfds);
> -         }
> -         FD_CLR(i, writefds);
> -         FD_CLR(i, exceptfds);
> -         break;
> -#endif
>       case FTYPE_TAP:
>       case FTYPE_BLK:
>       case FTYPE_KBD:
> diff --git a/lib/xs.c b/lib/xs.c
> index 4af0f960..c12341aa 100644
> --- a/lib/xs.c
> +++ b/lib/xs.c
> @@ -18,23 +18,56 @@ static inline int _xs_fileno(struct xs_handle *h) {
>      return (intptr_t) h;
>  }
>  
> +static int xs_close_fd(struct file *file)
> +{
> +    struct xenbus_event *event, *next;
> +
> +    for (event = file->dev; event; event = next)
> +    {
> +        next = event->next;
> +        free(event);
> +    }
> +
> +    return 0;
> +}
> +
> +static bool xs_can_read(struct file *file)
> +{
> +    return file && file->dev;
> +}
> +
> +static const struct file_ops xenbus_ops = {
> +    .name = "xenbus",
> +    .close = xs_close_fd,
> +    .select_rd = xs_can_read,
> +};
> +
> +static unsigned int ftype_xenbus;
> +
> +__attribute__((constructor))
> +static void xs_initialize(void)
> +{
> +    ftype_xenbus = alloc_file_type(&xenbus_ops);
> +}
> +
>  struct xs_handle *xs_daemon_open()
>  {
> -    int fd = alloc_fd(FTYPE_XENBUS);
> -    files[fd].dev = NULL;
> -    printk("xs_daemon_open -> %d, %p\n", fd, &files[fd].dev);
> +    int fd;
> +    struct file *file;
> +
> +    fd = alloc_fd(ftype_xenbus);
> +    file = get_file_from_fd(fd);
> +    if ( !file )
> +        return NULL;
> +
> +    file->dev = NULL;
> +    printk("xs_daemon_open -> %d, %p\n", fd, &file->dev);
>      return (void*)(intptr_t) fd;
>  }
>  
>  void xs_daemon_close(struct xs_handle *h)
>  {
> -    int fd = _xs_fileno(h);
> -    struct xenbus_event *event, *next;
> -    for (event = files[fd].dev; event; event = next)
> -    {
> -        next = event->next;
> -        free(event);
> -    }
> +    close(_xs_fileno(h));
>  }
>  
>  int xs_fileno(struct xs_handle *h)
> @@ -169,18 +202,20 @@ char **xs_directory(struct xs_handle *h, 
> xs_transaction_t t,
>  
>  bool xs_watch(struct xs_handle *h, const char *path, const char *token)
>  {
> -    int fd = _xs_fileno(h);
> +    struct file *file = get_file_from_fd(_xs_fileno(h));
> +
>      printk("xs_watch(%s, %s)\n", path, token);
>      return xs_bool(xenbus_watch_path_token(XBT_NULL, path, token,
> -                   (xenbus_event_queue *)&files[fd].dev));
> +                   (xenbus_event_queue *)&file->dev));
>  }
>  
>  char **xs_read_watch(struct xs_handle *h, unsigned int *num)
>  {
> -    int fd = _xs_fileno(h);
>      struct xenbus_event *event;
> -    event = files[fd].dev;
> -    files[fd].dev = event->next;
> +    struct file *file = get_file_from_fd(_xs_fileno(h));
> +
> +    event = file->dev;
> +    file->dev = event->next;
>      printk("xs_read_watch() -> %s %s\n", event->path, event->token);
>      *num = 2;
>      return (char **) &event->path;
> diff --git a/xenbus/xenbus.c b/xenbus/xenbus.c
> index b687678f..785389fb 100644
> --- a/xenbus/xenbus.c
> +++ b/xenbus/xenbus.c
> @@ -393,6 +393,7 @@ static int allocate_xenbus_id(void)
>  void init_xenbus(void)
>  {
>      int err;
> +
>      DEBUG("init_xenbus called.\n");
>      create_thread("xenstore", xenbus_thread_func, NULL);
>      DEBUG("buf at %p.\n", xenstore_buf);
> -- 
> 2.26.2
> 

-- 
Samuel
 RR> Ce que je cherche à démontrer, c'est qu'il est injuste de faire
 RR> l'amalgame entre du bulk mail et du courrier non-solicité très ciblé
 un suppositoire non reclamé, meme tres bien ciblé, reste un suppositoire.
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