fallocate: fix FALLOC_FL_ZERO_RANGE flag check

Reported-by: Bernhard Voelker <mail@bernhard-voelker.de>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/fallocate.c b/sys-utils/fallocate.c
index e5c149bb528c9c4f8aa85ba56ca8be4a70093131..d950f9c57a316547970b78cb88f8afe92efbded3 100644 (file)
--- a/sys-utils/fallocate.c
+++ b/sys-utils/fallocate.c
@@ -80,7 +80,7 @@ static void __attribute__((__noreturn__)) usage(FILE *out)
        fputs(_(" -l, --length <num>   length of the (de)allocation, in bytes\n"), out);
        fputs(_(" -n, --keep-size      don't modify the length of the file\n"), out);
        fputs(_(" -o, --offset <num>   offset of the (de)allocation, in bytes\n"), out);
-       fputs(_(" -p, --punch-hole     punch holes in the file\n"), out);
+       fputs(_(" -p, --punch-hole     punch holes in the file (implies --keep-size)\n"), out);
        fputs(_(" -z, --zero-range     zeroes a range in the file\n"), out);
        fputs(_(" -v, --verbose        verbose mode\n"), out);
 
@@ -326,6 +326,7 @@ int main(int argc, char **argv)
                }
        }
        if (dig) {
+               /* for --dig-holes the default is analyze all file */
                if (mode != 0)
                        errx(EXIT_FAILURE,
                             _("Can't use other modes with --dig-holes"));
@@ -334,6 +335,7 @@ int main(int argc, char **argv)
                if (length < 0)
                        errx(EXIT_FAILURE, _("invalid length value specified"));
        } else {
+               /* it's safer to require the range specification (--length --offset) */
                if (length == -2LL)
                        errx(EXIT_FAILURE, _("no length argument specified"));
                if (length <= 0)
@@ -343,8 +345,10 @@ int main(int argc, char **argv)
                errx(EXIT_FAILURE, _("invalid offset value specified"));
        if (optind == argc)
                errx(EXIT_FAILURE, _("no filename specified."));
-       if (mode & ~(FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE))
-               errx(EXIT_FAILURE, _("only -n mode can be used with "
+
+       if ((mode & FALLOC_FL_ZERO_RANGE) &&
+           (mode & ~(FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE)))
+               errx(EXIT_FAILURE, _("only --keep-size mode can be used with "
                                     "--zero-range"));
 
        filename = argv[optind++];