Disallow sizes with increasing unit size

Things like 3B4T, 4B50B, 400 100 (meaning 4*1024**4+3, 54, and 500,
respectively) are now disallowed. It is necessary to say 4T3B, 54B,
500 instead. I think this was confusing and error prone.

As a special form, 400B 100 is allowed, i.e. "B" suffix is treated
as different from "", although they mean the same thing.

2 files changed, 31 insertions, 18 deletions

diff --git a/src/shared/util.c b/src/shared/util.c
index 3164515a9e..285a263cdb 100644
--- a/src/shared/util.c
+++ b/src/shared/util.c
@@ -2157,31 +2157,31 @@ int parse_size(const char *t, off_t base, off_t *size) {
         };
 
         static const struct table iec[] = {
-                { "B", 1 },
-                { "K", 1024ULL },
-                { "M", 1024ULL*1024ULL },
-                { "G", 1024ULL*1024ULL*1024ULL },
-                { "T", 1024ULL*1024ULL*1024ULL*1024ULL },
-                { "P", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
                 { "E", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
+                { "P", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
+                { "T", 1024ULL*1024ULL*1024ULL*1024ULL },
+                { "G", 1024ULL*1024ULL*1024ULL },
+                { "M", 1024ULL*1024ULL },
+                { "K", 1024ULL },
+                { "B", 1 },
                 { "", 1 },
         };
 
         static const struct table si[] = {
-                { "B", 1 },
-                { "K", 1000ULL },
-                { "M", 1000ULL*1000ULL },
-                { "G", 1000ULL*1000ULL*1000ULL },
-                { "T", 1000ULL*1000ULL*1000ULL*1000ULL },
-                { "P", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
                 { "E", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
+                { "P", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
+                { "T", 1000ULL*1000ULL*1000ULL*1000ULL },
+                { "G", 1000ULL*1000ULL*1000ULL },
+                { "M", 1000ULL*1000ULL },
+                { "K", 1000ULL },
+                { "B", 1 },
                 { "", 1 },
         };
 
         const struct table *table;
         const char *p;
         unsigned long long r = 0;
-        unsigned n_entries;
+        unsigned n_entries, start_pos = 0;
 
         assert(t);
         assert(base == 1000 || base == 1024);
@@ -2235,7 +2235,7 @@ int parse_size(const char *t, off_t base, off_t *size) {
 
                 e += strspn(e, WHITESPACE);
 
-                for (i = 0; i < n_entries; i++)
+                for (i = start_pos; i < n_entries; i++)
                         if (startswith(e, table[i].suffix)) {
                                 unsigned long long tmp;
                                 if ((unsigned long long) l + (frac > 0) > ULLONG_MAX / table[i].factor)
@@ -2249,6 +2249,8 @@ int parse_size(const char *t, off_t base, off_t *size) {
                                         return -ERANGE;
 
                                 p = e + strlen(table[i].suffix);
+
+                                start_pos = i + 1;
                                 break;
                         }
 
diff --git a/src/test/test-util.c b/src/test/test-util.c
index 74f83a2629..1de06dbda8 100644
--- a/src/test/test-util.c
+++ b/src/test/test-util.c
@@ -460,21 +460,32 @@ static void test_parse_size(void) {
         assert_se(parse_size("3.0 K", 1024, &bytes) == 0);
         assert_se(bytes == 3*1024);
 
-        assert_se(parse_size("3. 0 K", 1024, &bytes) == 0);
-        assert_se(bytes == 3);
+        assert_se(parse_size("3. 0 K", 1024, &bytes) == -EINVAL);
 
         assert_se(parse_size(" 4 M 11.5K", 1024, &bytes) == 0);
         assert_se(bytes == 4*1024*1024 + 11 * 1024 + 512);
 
-        assert_se(parse_size("3B3.5G", 1024, &bytes) == 0);
+        assert_se(parse_size("3B3.5G", 1024, &bytes) == -EINVAL);
+
+        assert_se(parse_size("3.5G3B", 1024, &bytes) == 0);
         assert_se(bytes == 3ULL*1024*1024*1024 + 512*1024*1024 + 3);
 
-        assert_se(parse_size("3B3G4T", 1024, &bytes) == 0);
+        assert_se(parse_size("3.5G 4B", 1024, &bytes) == 0);
+        assert_se(bytes == 3ULL*1024*1024*1024 + 512*1024*1024 + 4);
+
+        assert_se(parse_size("3B3G4T", 1024, &bytes) == -EINVAL);
+
+        assert_se(parse_size("4T3G3B", 1024, &bytes) == 0);
+        assert_se(bytes == (4ULL*1024 + 3)*1024*1024*1024 + 3);
+
+        assert_se(parse_size(" 4 T 3 G 3 B", 1024, &bytes) == 0);
         assert_se(bytes == (4ULL*1024 + 3)*1024*1024*1024 + 3);
 
         assert_se(parse_size("12P", 1024, &bytes) == 0);
         assert_se(bytes == 12ULL * 1024*1024*1024*1024*1024);
 
+        assert_se(parse_size("12P12P", 1024, &bytes) == -EINVAL);
+
         assert_se(parse_size("3E 2P", 1024, &bytes) == 0);
         assert_se(bytes == (3 * 1024 + 2ULL) * 1024*1024*1024*1024*1024);