xfsprogs/xfsprogs-3.1.1-empty-blkid-...

74 lines
2.1 KiB
Diff

From: Christoph Hellwig <hch@lst.de>
Date: Fri, 5 Feb 2010 07:52:52 +0000 (+0100)
Subject: mkfs.xfs: fix detection of empty devices
X-Git-Url: http://git.kernel.org/?p=fs%2Fxfs%2Fxfsprogs-dev.git;a=commitdiff_plain;h=c2b707cf506c83ad4ab38c97c11cf358cc0bec88
mkfs.xfs: fix detection of empty devices
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.
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@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
---
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 9baf116..2d09e36 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -322,24 +322,40 @@ check_overwrite(
if (!pr)
goto out;
- if (blkid_probe_enable_partitions(pr, 1))
+ ret = blkid_probe_enable_partitions(pr, 1);
+ if (ret < 0)
goto out;
- if (blkid_do_fullprobe(pr))
+ ret = blkid_do_fullprobe(pr);
+ if (ret < 0)
goto out;
- ret = 0;
+ /*
+ * 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.
+ */
+ if (ret) {
+ ret = 0;
+ goto out;
+ }
+
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);
}
+ ret = 1;
out:
if (pr)