Re: [PATCH v2] btrfs-progs: force overwrite should wipe stale SB
On Thu, Oct 02, 2014 at 07:22:09AM +0800, Anand Jain wrote: (I am unable to reproduce the issue, tried to go back with progs versions but still the same. So as of now this code remains untested, suggest to wait till we have a reproducible test case). Here is a test case which says it all.. mkfs.xfs -f $DEV mkfs.btrfs -f $DEV mount $DEV $MNT mount: /dev/vdiskc: more filesystems detected. This should not happen, use -t type to explicitly specify the filesystem type or use wipefs(8) to clean up the device. mount: you must specify the filesystem type with this patch btrfs_prepare_device() also wipes old FS if any, btrfs_prepare_device() is called after we have verified that user has provided -f option. v2: to satisfy the backward compatibility issue, replace blkid_do_wipe() with local wipe function. Thank you, works for me, added to 3.17 queue. -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH v2] btrfs-progs: force overwrite should wipe stale SB
Thanks. Anand On 10/10/2014 03:39 PM, David Sterba wrote: On Thu, Oct 02, 2014 at 07:22:09AM +0800, Anand Jain wrote: (I am unable to reproduce the issue, tried to go back with progs versions but still the same. So as of now this code remains untested, suggest to wait till we have a reproducible test case). Here is a test case which says it all.. mkfs.xfs -f $DEV mkfs.btrfs -f $DEV mount $DEV $MNT mount: /dev/vdiskc: more filesystems detected. This should not happen, use -t type to explicitly specify the filesystem type or use wipefs(8) to clean up the device. mount: you must specify the filesystem type with this patch btrfs_prepare_device() also wipes old FS if any, btrfs_prepare_device() is called after we have verified that user has provided -f option. v2: to satisfy the backward compatibility issue, replace blkid_do_wipe() with local wipe function. Thank you, works for me, added to 3.17 queue. -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH v2] btrfs-progs: force overwrite should wipe stale SB
(I am unable to reproduce the issue, tried to go back with progs versions
but still the same. So as of now this code remains untested, suggest to
wait till we have a reproducible test case).
Here is a test case which says it all..
mkfs.xfs -f $DEV
mkfs.btrfs -f $DEV
mount $DEV $MNT
mount: /dev/vdiskc: more filesystems detected. This should not happen,
use -t type to explicitly specify the filesystem type or
use wipefs(8) to clean up the device.
mount: you must specify the filesystem type
with this patch btrfs_prepare_device() also wipes old FS if any,
btrfs_prepare_device() is called after we have verified that
user has provided -f option.
v2: to satisfy the backward compatibility issue, replace
blkid_do_wipe() with local wipe function.
Signed-off-by: Anand Jain anand.j...@oracle.com
Signed-off-by: David Sterba dste...@suse.cz
---
utils.c | 38 ++
1 file changed, 38 insertions(+)
diff --git a/utils.c b/utils.c
index fb78dd6..5f21737 100644
--- a/utils.c
+++ b/utils.c
@@ -680,6 +680,42 @@ int btrfs_add_to_fsid(struct btrfs_trans_handle *trans,
return 0;
}
+static void btrfs_wipe_existing_sb(int fd)
+{
+ const char *off = NULL;
+ size_t len = 0;
+ loff_t offset;
+ char buf[BUFSIZ];
+ int rc = 0;
+ blkid_probe pr = NULL;
+
+ pr = blkid_new_probe();
+ if (!pr)
+ return;
+
+ if (blkid_probe_set_device(pr, fd, 0, 0))
+ goto out;
+
+ rc = blkid_probe_lookup_value(pr, SBMAGIC_OFFSET, off, NULL);
+ if (!rc)
+ rc = blkid_probe_lookup_value(pr, SBMAGIC, NULL, len);
+
+ if (rc || len == 0 || off == NULL)
+ goto out;
+
+ offset = strtoll(off, NULL, 10);
+ if (len sizeof(buf))
+ len = sizeof(buf);
+
+ memset(buf, 0, len);
+ rc = pwrite(fd, buf, len, offset);
+ fsync(fd);
+
+out:
+ blkid_free_probe(pr);
+ return;
+}
+
int btrfs_prepare_device(int fd, char *file, int zero_end, u64
*block_count_ret,
u64 max_block_count, int *mixed, int discard)
{
@@ -731,6 +767,8 @@ int btrfs_prepare_device(int fd, char *file, int zero_end,
u64 *block_count_ret,
return 1;
}
+ btrfs_wipe_existing_sb(fd);
+
*block_count_ret = block_count;
return 0;
}
--
2.0.0.153.g79d
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