fallocate: Improve argument range check

If length or offset arguments are invalid, fail early on and add more
information about what went wrong. Also simplify later argument checks.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>

diff --git a/sys-utils/fallocate.c b/sys-utils/fallocate.c
index 2b3b0e4bf2dd0c6ec1f8840c31620382eb59c69f..622e0c39c1923904d296519cdc8bdd5503bfef35 100644 (file)
--- a/sys-utils/fallocate.c
+++ b/sys-utils/fallocate.c
@@ -371,7 +371,7 @@ int main(int argc, char **argv)
        int     mode = 0;
        int     dig = 0;
        int     posix = 0;
-       off_t   length = -2;
+       off_t   length = -1;
        off_t   offset = 0;
 
        static const struct option longopts[] = {
@@ -421,12 +421,16 @@ int main(int argc, char **argv)
                        break;
                case 'l':
                        length = cvtnum(optarg);
+                       if (length < 0)
+                               err(EXIT_FAILURE, _("invalid length"));
                        break;
                case 'n':
                        mode |= FALLOC_FL_KEEP_SIZE;
                        break;
                case 'o':
                        offset = cvtnum(optarg);
+                       if (offset < 0)
+                               err(EXIT_FAILURE, _("invalid offset"));
                        break;
                case 'p':
                        mode |= FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
@@ -466,19 +470,15 @@ int main(int argc, char **argv)
 
        if (dig || report) {
                /* for --dig-holes and --report-holes the default is analyze all file */
-               if (length == -2)
-                       length = 0;
                if (length < 0)
-                       errx(EXIT_FAILURE, _("invalid length"));
+                       length = 0;
        } else {
                /* it's safer to require the range specification (--length --offset) */
-               if (length == -2)
+               if (length < 0)
                        errx(EXIT_FAILURE, _("no length argument specified"));
-               if (length <= 0)
+               if (length == 0)
                        errx(EXIT_FAILURE, _("invalid length"));
        }
-       if (offset < 0)
-               errx(EXIT_FAILURE, _("invalid offset"));
 
        /* O_CREAT makes sense only for the default fallocate(2) behavior
         * when mode is no specified and new space is allocated */