Fix strict-aliasing compile warning in partition table scanning

diff --git a/WHATS_NEW b/WHATS_NEW
index 105340180084e5f5fed4ba32b298b0f918fbac2b..1df868cfa91e621db366ae193c8c055f823d7804 100644 (file)
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.75 - 
 =====================================
+  Fix strict-aliasing compile warning in partition table scanning.
   Add an option to automatically extend snapshots through dmeventd.
   Remove dependency on libm, floor() is replaced with integer algorithm.
   Fix hang when repairing a mirrored-log that had both devs fail.

diff --git a/lib/device/device.c b/lib/device/device.c
index 593e642d5c65a595a506c6faf97ff2e2e93f57c9..91eb14c88d3b509b9c56c8570d2116d09ed19e14 100644 (file)
--- a/lib/device/device.c
+++ b/lib/device/device.c
@@ -58,9 +58,11 @@ static int _has_partition_table(struct device *dev)
 {
        int ret = 0;
        unsigned p;
-       uint16_t buf[SECTOR_SIZE/sizeof(uint16_t)];
-       uint16_t *part_magic;
-       struct partition *part;
+       struct {
+               uint8_t skip[PART_OFFSET];
+               struct partition part[4];
+               uint16_t magic;
+       } __attribute__((packed)) buf; /* sizeof() == SECTOR_SIZE */
 
        if (!dev_read(dev, UINT64_C(0), sizeof(buf), &buf))
                return_0;
@@ -68,17 +70,15 @@ static int _has_partition_table(struct device *dev)
        /* FIXME Check for other types of partition table too */
 
        /* Check for msdos partition table */
-       part_magic = buf + PART_MAGIC_OFFSET/sizeof(buf[0]);
-       if ((*part_magic == xlate16(PART_MAGIC))) {
-               part = (struct partition *) (buf + PART_OFFSET/sizeof(buf[0]));
-               for (p = 0; p < 4; p++, part++) {
+       if (buf.magic == xlate16(PART_MAGIC)) {
+               for (p = 0; p < 4; ++p) {
                        /* Table is invalid if boot indicator not 0 or 0x80 */
-                       if ((part->boot_ind & 0x7f)) {
+                       if (buf.part[p].boot_ind & 0x7f) {
                                ret = 0;
                                break;
                        }
                        /* Must have at least one non-empty partition */
-                       if (part->nr_sects)
+                       if (buf.part[p].nr_sects)
                                ret = 1;
                }
        }