[PATCH v2 28/28] fs/squashfs: implement exists() function

[João Marcos Costa]

Reviewed-by Joao Marcos Costa <jmcosta944 at gmail.com>

Em ter., 3 de nov. de 2020 às 08:12, Richard Genoud <
richard.genoud at posteo.net> escreveu:

> This permits to find a file and use the distro_bootcmd
>
> Signed-off-by: Richard Genoud <richard.genoud at posteo.net>
> ---
>  fs/fs.c            |  2 +-
>  fs/squashfs/sqfs.c | 38 ++++++++++++++++++++++++++++++++++++++
>  include/squashfs.h |  1 +
>  3 files changed, 40 insertions(+), 1 deletion(-)
>
> diff --git a/fs/fs.c b/fs/fs.c
> index fb27c910d4f..7a4020607a3 100644
> --- a/fs/fs.c
> +++ b/fs/fs.c
> @@ -296,7 +296,7 @@ static struct fstype_info fstypes[] = {
>                 .size = sqfs_size,
>                 .close = sqfs_close,
>                 .closedir = sqfs_closedir,
> -               .exists = fs_exists_unsupported,
> +               .exists = sqfs_exists,
>                 .uuid = fs_uuid_unsupported,
>                 .write = fs_write_unsupported,
>                 .ln = fs_ln_unsupported,
> diff --git a/fs/squashfs/sqfs.c b/fs/squashfs/sqfs.c
> index a96c1d4f564..c8e8d682cd4 100644
> --- a/fs/squashfs/sqfs.c
> +++ b/fs/squashfs/sqfs.c
> @@ -1657,6 +1657,44 @@ free_strings:
>         return ret;
>  }
>
> +int sqfs_exists(const char *filename)
> +{
> +       struct fs_dir_stream *dirsp = NULL;
> +       struct squashfs_dir_stream *dirs;
> +       char *dir, *file;
> +       struct fs_dirent *dent;
> +       int ret;
> +
> +       sqfs_split_path(&file, &dir, filename);
> +       /*
> +        * sqfs_opendir will uncompress inode and directory tables, and
> will
> +        * return a pointer to the directory that contains the requested
> file.
> +        */
> +       ret = sqfs_opendir(dir, &dirsp);
> +       if (ret) {
> +               ret = -EINVAL;
> +               goto free_strings;
> +       }
> +
> +       dirs = (struct squashfs_dir_stream *)dirsp;
> +
> +       while (!sqfs_readdir(dirsp, &dent)) {
> +               ret = strcmp(dent->name, file);
> +               if (!ret)
> +                       break;
> +               free(dirs->entry);
> +               dirs->entry = NULL;
> +       }
> +
> +       sqfs_closedir(dirsp);
> +
> +free_strings:
> +       free(dir);
> +       free(file);
> +
> +       return ret == 0;
> +}
> +
>  void sqfs_close(void)
>  {
>         free(ctxt.sblk);
> diff --git a/include/squashfs.h b/include/squashfs.h
> index 819cf8c2da8..7489eefa1f2 100644
> --- a/include/squashfs.h
> +++ b/include/squashfs.h
> @@ -19,6 +19,7 @@ int sqfs_probe(struct blk_desc *fs_dev_desc,
>  int sqfs_read(const char *filename, void *buf, loff_t offset,
>               loff_t len, loff_t *actread);
>  int sqfs_size(const char *filename, loff_t *size);
> +int sqfs_exists(const char *filename);
>  void sqfs_close(void);
>  void sqfs_closedir(struct fs_dir_stream *dirs);
>
>

-- 
Atenciosamente,
João Marcos Costa

www.linkedin.com/in/jmarcoscosta/
https://github.com/jmarcoscosta