util: add virDiskNameParse to handle disk and partition idx

Introduce a new helper function "virDiskNameParse" which extends
virDiskNameToIndex but handling both disk index and partition index.
Also rework virDiskNameToIndex to be based on virDiskNameParse.
A test is also added for this function testing both valid and
invalid disk names.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>

src/libvirt_private.syms

@@ -148,6 +148,7 @@ virDomainCapsNew;
 
 # conf/domain_conf.h
 virBlkioDeviceArrayClear;
+virDiskNameParse;
 virDiskNameToBusDeviceIndex;
 virDiskNameToIndex;
 virDomainActualNetDefFree;

src/util/virutil.c

@@ -537,14 +537,17 @@ const char *virEnumToString(const char *const*types,
 }
 
 /* Translates a device name of the form (regex) /^[fhv]d[a-z]+[0-9]*$/
- * into the corresponding index (e.g. sda => 0, hdz => 25, vdaa => 26)
- * Note that any trailing string of digits is simply ignored.
+ * into the corresponding index and partition number
+ * (e.g. sda0 => (0,0), hdz2 => (25,2), vdaa12 => (26,12))
  * @param name The name of the device
- * @return name's index, or -1 on failure
+ * @param disk The disk index to be returned
+ * @param partition The partition index to be returned
+ * @return 0 on success, or -1 on failure
  */
-int virDiskNameToIndex(const char *name)
+int virDiskNameParse(const char *name, int *disk, int *partition)
 {
     const char *ptr = NULL;
+    char *rem;
     int idx = 0;
     static char const* const drive_prefix[] = {"fd", "hd", "vd", "sd", "xvd", "ubd"};
     size_t i;
@@ -573,6 +576,36 @@ int virDiskNameToIndex(const char *name)
     if (ptr[n_digits] != '\0')
         return -1;
 
+    *disk = idx;
+
+    /* Convert trailing digits into our partition index */
+    if (partition) {
+        *partition = 0;
+
+        /* Shouldn't start by zero */
+        if (n_digits > 1 && *ptr == '0')
+            return -1;
+
+        if (n_digits && virStrToLong_i(ptr, &rem, 10, partition) < 0)
+            return -1;
+    }
+
+    return 0;
+}
+
+/* Translates a device name of the form (regex) /^[fhv]d[a-z]+[0-9]*$/
+ * into the corresponding index (e.g. sda => 0, hdz => 25, vdaa => 26)
+ * Note that any trailing string of digits is simply ignored.
+ * @param name The name of the device
+ * @return name's index, or -1 on failure
+ */
+int virDiskNameToIndex(const char *name)
+{
+    int idx;
+
+    if (virDiskNameParse(name, &idx, NULL))
+        idx = -1;
+
     return idx;
 }
 

src/util/virutil.h

@@ -67,6 +67,7 @@ int virDoubleToStr(char **strp, double number)
 char *virFormatIntDecimal(char *buf, size_t buflen, int val)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
 
+int virDiskNameParse(const char *name, int *disk, int *partition);
 int virDiskNameToIndex(const char* str);
 char *virIndexToDiskName(int idx, const char *prefix);
 

tests/utiltest.c

@@ -23,6 +23,23 @@ static const char* diskNames[] = {
     "sdia", "sdib", "sdic", "sdid", "sdie", "sdif", "sdig", "sdih", "sdii", "sdij", "sdik", "sdil", "sdim", "sdin", "sdio", "sdip", "sdiq", "sdir", "sdis", "sdit", "sdiu", "sdiv", "sdiw", "sdix", "sdiy", "sdiz"
 };
 
+struct testDiskName
+{
+    const char *name;
+    int idx;
+    int partition;
+};
+
+static struct testDiskName diskNamesPart[] = {
+    {"sda0",          0,           0},
+    {"sdb10",         1,          10},
+    {"sdc2147483647", 2,  2147483647},
+};
+
+static const char* diskNamesInvalid[] = {
+    "sda00", "sda01", "sdb-1"
+};
+
 static int
 testIndexToDiskName(const void *data ATTRIBUTE_UNUSED)
 {
@@ -79,6 +96,44 @@ testDiskNameToIndex(const void *data ATTRIBUTE_UNUSED)
 
 
 
+static int
+testDiskNameParse(const void *data ATTRIBUTE_UNUSED)
+{
+    size_t i;
+    int idx;
+    int partition;
+    struct testDiskName *disk = NULL;
+
+    for (i = 0; i < ARRAY_CARDINALITY(diskNamesPart); ++i) {
+        disk = &diskNamesPart[i];
+        if (virDiskNameParse(disk->name, &idx, &partition))
+            return -1;
+
+        if (disk->idx != idx) {
+            VIR_TEST_DEBUG("\nExpect [%d]\n", disk->idx);
+            VIR_TEST_DEBUG("Actual [%d]\n", idx);
+            return -1;
+        }
+
+        if (disk->partition != partition) {
+            VIR_TEST_DEBUG("\nExpect [%d]\n", disk->partition);
+            VIR_TEST_DEBUG("Actual [%d]\n", partition);
+            return -1;
+        }
+    }
+
+    for (i = 0; i < ARRAY_CARDINALITY(diskNamesInvalid); ++i) {
+        if (!virDiskNameParse(diskNamesInvalid[i], &idx, &partition)) {
+            VIR_TEST_DEBUG("Should Fail [%s]\n", diskNamesInvalid[i]);
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+
+
 struct testVersionString
 {
     const char *string;
@@ -220,6 +275,7 @@ mymain(void)
 
     DO_TEST(IndexToDiskName);
     DO_TEST(DiskNameToIndex);
+    DO_TEST(DiskNameParse);
     DO_TEST(ParseVersionString);
     DO_TEST(RoundValueToPowerOfTwo);
     DO_TEST(OverflowCheckMacro);