[LTP] [PATCH 1/3] libswap: add two method to create swapfile

[Li Wang]

On Tue, Mar 19, 2024 at 3:01 PM Li Wang <liwang@redhat.com> wrote:

> This introduces new functionality to the libswap library by adding
> two methods for creating a swapfile: SWAPFILE_BY_SIZE and
> SWAPFILE_BY_BLOCKS.
> The make_swapfile function is updated to accept an additional enum
> swapfile_method parameter to specify the creation method.
>
> Two macros, MAKE_SWAPFILE_SIZE and MAKE_SWAPFILE_BLKS, are defined
> to simplify the interface for creating swapfiles by size and by
> blocks respectively.
> ---
>  include/libswap.h         | 16 ++++++++++++++--
>  libs/libltpswap/libswap.c | 30 ++++++++++++++++++++++--------
>  2 files changed, 36 insertions(+), 10 deletions(-)
>
> diff --git a/include/libswap.h b/include/libswap.h
> index 8c75e20ae..1dee907f0 100644
> --- a/include/libswap.h
> +++ b/include/libswap.h
> @@ -11,10 +11,22 @@
>  #ifndef __LIBSWAP_H__
>  #define __LIBSWAP_H__
>
> +enum swapfile_method {
> +    SWAPFILE_BY_SIZE,
> +    SWAPFILE_BY_BLOCKS
> +};
> +
>  /*
> - * Make a swap file
> + * Create a swapfile of a specified size or number of blocks.
>   */
> -int make_swapfile(const char *swapfile, int blocks, int safe);
> +int make_swapfile(const char *swapfile, unsigned int num,
> +                       int safe, enum swapfile_method method);
> +
> +#define MAKE_SWAPFILE_SIZE(swapfile, size, safe) \
> +    make_swapfile(swapfile, size, safe, SWAPFILE_BY_SIZE)
> +
> +#define MAKE_SWAPFILE_BLKS(swapfile, blocks, safe) \
> +    make_swapfile(swapfile, blocks, safe, SWAPFILE_BY_BLOCKS)
>
>  /*
>   * Check swapon/swapoff support status of filesystems or files
> diff --git a/libs/libltpswap/libswap.c b/libs/libltpswap/libswap.c
> index a26ea25e4..6a0f24ed2 100644
> --- a/libs/libltpswap/libswap.c
> +++ b/libs/libltpswap/libswap.c
> @@ -133,23 +133,37 @@ out:
>         return contiguous;
>  }
>
> -int make_swapfile(const char *swapfile, int blocks, int safe)
> +int make_swapfile(const char *swapfile, unsigned int num, int safe, enum
> swapfile_method method)
>  {
>         struct statvfs fs_info;
>         unsigned long blk_size, bs;
>         size_t pg_size = sysconf(_SC_PAGESIZE);
>         char mnt_path[100];
> +       unsigned int blocks;
>
>         if (statvfs(".", &fs_info) == -1)
>                 return -1;
>
>         blk_size = fs_info.f_bsize;
>
> -       /* To guarantee at least one page can be swapped out */
> -       if (blk_size * blocks < pg_size)
> -               bs = pg_size;
> -       else
> -               bs = blk_size;
>



> +       switch (method) {
> +       case SWAPFILE_BY_BLOCKS:
> +               blocks = num;
> +               if (blk_size * blocks < pg_size)
> +                       bs = pg_size;
> +               else
> +                       bs = blk_size;
> +       break;
> +       case SWAPFILE_BY_SIZE:
> +               if (num * 1024 * 1024 < pg_size)
> +                       bs = pg_size;
> +               else
> +                       bs = blk_size;
> +               blocks = (num * 1024 * 1024) / blk_size;
> +       break;
> +       default:
> +               return -1;
> +       }
>

Obviously, this part is too ugly, I would take the way Wei posted in
another thread, thanks.

Something like:

+       if (method == SWAPFILE_BY_SIZE)
+               blocks = num * 1024 * 1024 / blk_size;
+       else if (method == SWAPFILE_BY_BLOCKS)
+               blocks = num;
+       else
+               tst_brk(TBROK, "Invalide method.");



>
>         if (sscanf(swapfile, "%[^/]", mnt_path) != 1)
>                 tst_brk(TBROK, "sscanf failed");
> @@ -175,13 +189,13 @@ int make_swapfile(const char *swapfile, int blocks,
> int safe)
>         argv[2] = NULL;
>
>         return tst_cmd(argv, "/dev/null", "/dev/null", safe ?
> -                                  TST_CMD_PASS_RETVAL |
> TST_CMD_TCONF_ON_MISSING : 0);
> +                       TST_CMD_PASS_RETVAL | TST_CMD_TCONF_ON_MISSING :
> 0);
>  }
>
>  bool is_swap_supported(const char *filename)
>  {
>         int i, sw_support = 0;
> -       int ret = make_swapfile(filename, 10, 1);
> +       int ret = MAKE_SWAPFILE_BLKS(filename, 10, 1);
>         int fi_contiguous = file_is_contiguous(filename);
>         long fs_type = tst_fs_type(filename);
>         const char *fstype = tst_fs_type_name(fs_type);
> --
> 2.40.1
>
>
> --
> Mailing list info: https://lists.linux.it/listinfo/ltp
>
>

-- 
Regards,
Li Wang