repart: don't try to determine sector size from a disk image we should consider empty

If we are told to start from scratch we shouldn't look into the old
image to determine sector size. Looking there is confusing at best, but
plain wrong in many other cases.

diff --git a/src/partition/repart.c b/src/partition/repart.c
index 9b6b8a5a14cfde6b57204589c775b2cca33933d3..36842b1c7a2a8b575e9ae24f677af7d948513519 100644 (file)
--- a/src/partition/repart.c
+++ b/src/partition/repart.c
@@ -2326,24 +2326,31 @@ static int context_load_partition_table(Context *context) {
                 uint32_t ssz;
                 struct stat st;
 
-                r = context_open_and_lock_backing_fd(context->node, arg_dry_run ? LOCK_SH : LOCK_EX,
-                                                     &context->backing_fd);
+                r = context_open_and_lock_backing_fd(
+                                context->node,
+                                arg_dry_run ? LOCK_SH : LOCK_EX,
+                                &context->backing_fd);
                 if (r < 0)
                         return r;
 
                 if (fstat(context->backing_fd, &st) < 0)
                         return log_error_errno(errno, "Failed to stat %s: %m", context->node);
 
-                /* Auto-detect sector size if not specified. */
-                r = probe_sector_size_prefer_ioctl(context->backing_fd, &ssz);
-                if (r < 0)
-                        return log_error_errno(r, "Failed to probe sector size of '%s': %m", context->node);
+                if (IN_SET(arg_empty, EMPTY_REQUIRE, EMPTY_FORCE, EMPTY_CREATE) && S_ISREG(st.st_mode))
+                        /* Don't probe sector size from partition table if we are supposed to strat from an empty disk */
+                        fs_secsz = ssz = 512;
+                else {
+                        /* Auto-detect sector size if not specified. */
+                        r = probe_sector_size_prefer_ioctl(context->backing_fd, &ssz);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to probe sector size of '%s': %m", context->node);
 
-                /* If we found the sector size and we're operating on a block device, use it as the file
-                 * system sector size as well, as we know its the sector size of the actual block device and
-                 * not just the offset at which we found the GPT header. */
-                if (r > 0 && S_ISBLK(st.st_mode))
-                        fs_secsz = ssz;
+                        /* If we found the sector size and we're operating on a block device, use it as the file
+                         * system sector size as well, as we know its the sector size of the actual block device and
+                         * not just the offset at which we found the GPT header. */
+                        if (r > 0 && S_ISBLK(st.st_mode))
+                                fs_secsz = ssz;
+                }
 
                 r = fdisk_save_user_sector_size(c, /* phy= */ 0, ssz);
         }