btrfs-progs: extend parse_range API to accept a relaxed range

In some cases we want to accept a range of type [a..a]. Add a new
function to do the 'a < b' check for the caller and use it.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/cmds-balance.c b/cmds-balance.c
index d7f8148..053cd9b 100644 (file)
--- a/cmds-balance.c
+++ b/cmds-balance.c
@@ -128,9 +128,10 @@ static int parse_range(const char *range, u64 *start, u64 *end)
                        return 1;
        }
 
-       if (*start >= *end) {
-               fprintf(stderr, "Range %llu..%llu doesn't make "
-                       "sense\n", (unsigned long long)*start,
+       if (*start > *end) {
+               fprintf(stderr,
+                       "ERROR: range %llu..%llu doesn't make sense\n",
+                       (unsigned long long)*start,
                        (unsigned long long)*end);
                return 1;
        }
@@ -141,6 +142,25 @@ static int parse_range(const char *range, u64 *start, u64 *end)
        return 1;
 }
 
+/*
+ * Parse range and check if start < end
+ */
+static int parse_range_strict(const char *range, u64 *start, u64 *end)
+{
+       if (parse_range(range, start, end) == 0) {
+               if (*start >= *end) {
+                       fprintf(stderr,
+                               "ERROR: range %llu..%llu not allowed\n",
+                               (unsigned long long)*start,
+                               (unsigned long long)*end);
+                       return 1;
+               }
+               return 0;
+       }
+
+       return 1;
+}
+
 static int parse_filters(char *filters, struct btrfs_balance_args *args)
 {
        char *this_char;
@@ -198,7 +218,7 @@ static int parse_filters(char *filters, struct btrfs_balance_args *args)
                                       "an argument\n");
                                return 1;
                        }
-                       if (parse_range(value, &args->pstart, &args->pend)) {
+                       if (parse_range_strict(value, &args->pstart, &args->pend)) {
                                fprintf(stderr, "Invalid drange argument\n");
                                return 1;
                        }
@@ -209,7 +229,7 @@ static int parse_filters(char *filters, struct btrfs_balance_args *args)
                                       "an argument\n");
                                return 1;
                        }
-                       if (parse_range(value, &args->vstart, &args->vend)) {
+                       if (parse_range_strict(value, &args->vstart, &args->vend)) {
                                fprintf(stderr, "Invalid vrange argument\n");
                                return 1;
                        }