Re: [PATCH 4/6] tools/libfsimage: Add an fdopen() interface to libfsimage

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 06/11/2023 3:05 pm, Alejandro Vallejo wrote:
> diff --git a/tools/libfsimage/common/fsimage_priv.h 
> b/tools/libfsimage/common/fsimage_priv.h
> index 2274403557..779e433b37 100644
> --- a/tools/libfsimage/common/fsimage_priv.h
> +++ b/tools/libfsimage/common/fsimage_priv.h
> @@ -29,6 +29,7 @@ extern C {
>  #endif
>  
>  #include <sys/types.h>
> +#include <stdbool.h>
>  
>  #include "xenfsimage.h"
>  #include "xenfsimage_plugin.h"
> @@ -54,7 +55,7 @@ struct fsi_file {
>       void *ff_data;
>  };
>  
> -int find_plugin(fsi_t *, const char *, const char *);
> +int find_plugin(fsi_t *, const char *);
>  
>  #ifdef __cplusplus
>  };

These are the only two hunks in this file.  Is the stdbool include stale?

It seems to compile fine with it removed.

> diff --git a/tools/libfsimage/ext2fs-lib/ext2fs-lib.c 
> b/tools/libfsimage/ext2fs-lib/ext2fs-lib.c
> index 864a15b349..9f07ea288f 100644
> --- a/tools/libfsimage/ext2fs-lib/ext2fs-lib.c
> +++ b/tools/libfsimage/ext2fs-lib/ext2fs-lib.c
> @@ -25,15 +25,25 @@
>  #include INCLUDE_EXTFS_H
>  #include <errno.h>
>  #include <inttypes.h>
> +#include <stdio.h>
>  
>  static int
> -ext2lib_mount(fsi_t *fsi, const char *name, const char *options)
> +ext2lib_mount(fsi_t *fsi, const char *options)
>  {
>       int err;
>       char opts[30] = "";
>       ext2_filsys *fs;
>       uint64_t offset = fsip_fs_offset(fsi);
>  
> +     /*
> +      * We must choose unixfd_io_manager rather than unix_io_manager in
> +      * order for the library to accept fd strings instead of paths. It
> +      * still means we must pass a string representing an fd rather than
> +      * an int, but at least this way we don't need to pass paths around
> +      */
> +     char name[32] = {0};

For an int?  12 will do fine including a terminator, and practical
system limits leave it far smaller than that generally.

Given that it is guaranteed long enough, you don't need to zero it just
to have snprintf() write a well-formed string in.

~Andrew