From: Christoph Hellwig <hch@infradead.org>
To: Eric Sandeen <sandeen@redhat.com>
Cc: Jim Meyering <meyering@redhat.com>, xfs mailing list <xfs@oss.sgi.com>
Subject: Re: [PATCH v2] mkfs.xfs fix detection of empty devices
Date: Thu, 4 Feb 2010 17:18:22 -0500 [thread overview]
Message-ID: <20100204221822.GA26670@infradead.org> (raw)
In-Reply-To: <20100204194000.GA7229@infradead.org>
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>
Index: xfsprogs-dev/mkfs/xfs_mkfs.c
===================================================================
--- xfsprogs-dev.orig/mkfs/xfs_mkfs.c 2010-02-04 20:30:26.000000000 +0000
+++ xfsprogs-dev/mkfs/xfs_mkfs.c 2010-02-04 20:43:41.000000000 +0000
@@ -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)
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next prev parent reply other threads:[~2010-02-04 22:17 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-02-04 16:34 [PATCH] mkfs: don't try to detect filesystems on regular files via blkid Eric Sandeen
2010-02-04 16:46 ` Jim Meyering
2010-02-04 16:54 ` Eric Sandeen
2010-02-04 17:48 ` [PATCH V2] " Eric Sandeen
2010-02-04 19:43 ` Eric Sandeen
2010-02-04 19:40 ` [PATCH] mkfs.xfs fix detection of empty devices Christoph Hellwig
2010-02-04 20:15 ` Eric Sandeen
2010-02-04 22:18 ` Christoph Hellwig [this message]
2010-02-05 3:41 ` [PATCH v2] " Eric Sandeen
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