We currently fail to detect that a device does indeed not contain any
signature and we are indeed fine to proceed with it due to mishandling
the return value of blkid_do_fullprobe. Fix that up and add some
better diagnostics of the blkid detection. Also remove the size == 0
check in check_overwrite as blkid handles that just fine.
from RH bugzilla https://bugzilla.redhat.com/show_bug.cgi?id=561870
# dd if=/dev/zero of=k bs=1MB count=2 seek=20; mkfs.xfs k
# mkfs.xfs: probe of k failed, cannot detect existing filesystem.
# mkfs.xfs: Use the -f option to force overwrite
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: xfsprogs-dev/mkfs/xfs_mkfs.c
===================================================================
--- xfsprogs-dev.orig/mkfs/xfs_mkfs.c 2010-02-04 19:19:36.000000000 +0000
+++ xfsprogs-dev/mkfs/xfs_mkfs.c 2010-02-04 19:33:36.000000000 +0000
@@ -297,48 +297,47 @@ check_overwrite(
const char *type;
blkid_probe pr = NULL;
int ret;
- int fd;
- long long size;
- int bsz;
if (!device || !*device)
return 0;
ret = -1; /* will reset on success of all setup calls */
- fd = open(device, O_RDONLY);
- if (fd < 0)
- goto out;
- platform_findsizes(device, fd, &size, &bsz);
- close(fd);
-
- /* nothing to overwrite on a 0-length device */
- if (size == 0) {
- ret = 0;
- goto out;
- }
-
pr = blkid_new_probe_from_filename(device);
if (!pr)
goto out;
- if (blkid_probe_enable_partitions(pr, 1))
+ ret = blkid_probe_enable_partitions(pr, 1);
+ if (ret < 0)
+ goto out;
+
+ ret = blkid_do_fullprobe(pr);
+ if (ret < 0)
goto out;
- if (blkid_do_fullprobe(pr))
+ /*
+ * Blkid returns 1 for nothing found and 0 when it finds a signature,
+ * but we want the exact opposite, so reverse the return value here.
+ *
+ * In addition print some useful diagnostics about what actually is
+ * on the device.
+ */
+ ret = !ret;
+ if (!ret)
goto out;
- ret = 0;
if (!blkid_probe_lookup_value(pr, "TYPE", &type, NULL)) {
fprintf(stderr,
_("%s: %s appears to contain an existing "
"filesystem (%s).\n"), progname, device, type);
- ret = 1;
} else if (!blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL)) {
fprintf(stderr,
_("%s: %s appears to contain a partition "
"table (%s).\n"), progname, device, type);
- ret = 1;
+ } else {
+ fprintf(stderr,
+ _("%s: %s appears to contain something weird "
+ "according to blkid\n"), progname, device);
}
out:
|