Re: [musl] [PATCH 2/2] nftw: implement FTW_ACTIONRETVAL (GNU extension)

[Ismael Luceno <ismael@iodev.co.uk>]

I noticed a small bug, I'll submit a v2.

On 22/Jan/2022 14:26, Ismael Luceno wrote:
> Signed-off-by: Ismael Luceno <ismael@iodev.co.uk>
> ---
>  include/ftw.h   |  7 +++++++
>  src/misc/nftw.c | 32 ++++++++++++++++++++++----------
>  2 files changed, 29 insertions(+), 10 deletions(-)
> 
> diff --git a/include/ftw.h b/include/ftw.h
> index b15c062a8389..2e77dc76e11b 100644
> --- a/include/ftw.h
> +++ b/include/ftw.h
> @@ -21,6 +21,13 @@ extern "C" {
>  #define FTW_CHDIR 4
>  #define FTW_DEPTH 8
>  
> +#define FTW_ACTIONRETVAL  16
> +/* return values for callback */
> +#define FTW_CONTINUE	  0
> +#define FTW_STOP          1
> +#define FTW_SKIP_SUBTREE  2
> +#define FTW_SKIP_SIBLINGS 3
> +
>  struct FTW {
>  	int base;
>  	int level;
> diff --git a/src/misc/nftw.c b/src/misc/nftw.c
> index 0a35686e663d..4b934adcfb0c 100644
> --- a/src/misc/nftw.c
> +++ b/src/misc/nftw.c
> @@ -26,7 +26,7 @@ static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int,
>  	struct stat st;
>  	struct history new;
>  	int type;
> -	int r;
> +	int r, r2;
>  	int dfd;
>  	int err;
>  	struct FTW lev;
> @@ -72,12 +72,18 @@ static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int,
>  		if (!fd_limit) close(dfd);
>  	}
>  
> -	if (!(flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
> -		return r;
> +	if (!(flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev))) {
> +		if ((flags & FTW_ACTIONRETVAL)) {
> +			if (r == FTW_SKIP_SUBTREE)
> +				return 0;
> +			/* FTW_SKIP_SIBLINGS is saved for returning */
> +		} else
> +			return r;
> +	}
>  
>  	for (; h; h = h->chain)
>  		if (h->dev == st.st_dev && h->ino == st.st_ino)
> -			return 0;
> +			return r;
>  
>  	if ((type == FTW_D || type == FTW_DP) && fd_limit) {
>  		if (dfd < 0) {
> @@ -101,9 +107,12 @@ static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int,
>  				}
>  				path[j]='/';
>  				strcpy(path+j+1, de->d_name);
> -				if ((r=do_nftw(path, fn, fd_limit-1, flags, &new))) {
> +				if ((r2=do_nftw(path, fn, fd_limit-1, flags, &new))) {
> +					if ((flags & FTW_ACTIONRETVAL)
> +					    && r2 == FTW_SKIP_SIBLINGS)
> +						break;
>  					closedir(d);
> -					return r;
> +					return r2;
>  				}
>  			}
>  			closedir(d);
> @@ -114,10 +123,13 @@ static int do_nftw(char *path, int (*fn)(const char *, const struct stat *, int,
>  	}
>  
>  	path[l] = 0;
> -	if ((flags & FTW_DEPTH) && (r=fn(path, &st, type, &lev)))
> -		return r;
> -
> -	return 0;
> +	if (flags & FTW_DEPTH) {
> +		r = fn(path, &st, type, &lev);
> +		/* ignore FTW_SKIP_SUBTREE, the caller is broken */
> +		if ((flags & FTW_ACTIONRETVAL) && r == FTW_SKIP_SUBTREE)
> +			r = 0;
> +	}
> +	return r;
>  }
>  
>  int nftw(const char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int fd_limit, int flags)
> -- 
> 2.33.0
> 

-- 
Ismael Luceno
http://iodev.co.uk/