On 10/06/2018 06:14 PM, Eryu Guan wrote:
On Mon, Oct 01, 2018 at 04:44:35PM +0800, Anand Jain wrote:
We have a known bug in btrfs, that we let the device path be changed
after the device has been mounted. So using this loop hole the new
copied device would appears as if its mounted immediately after its
been copied. So this test case reproduces this issue.
For example:
Initially.. /dev/mmcblk0p4 is mounted as /
lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
mmcblk0 179:0 0 29.2G 0 disk
|-mmcblk0p4 179:4 0 4G 0 part /
|-mmcblk0p2 179:2 0 500M 0 part /boot
|-mmcblk0p3 179:3 0 256M 0 part [SWAP]
`-mmcblk0p1 179:1 0 256M 0 part /boot/efi
btrfs fi show
Label: none uuid: 07892354-ddaa-4443-90ea-f76a06accaba
Total devices 1 FS bytes used 1.40GiB
devid 1 size 4.00GiB used 3.00GiB path /dev/mmcblk0p4
Copy mmcblk0 to sda
dd if=/dev/mmcblk0 of=/dev/sda
And immediately after the copy completes the change in the device
superblock is notified which the automount scans using
btrfs device scan and the new device sda becomes the mounted root
device.
lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 1 14.9G 0 disk
|-sda4 8:4 1 4G 0 part /
|-sda2 8:2 1 500M 0 part
|-sda3 8:3 1 256M 0 part
`-sda1 8:1 1 256M 0 part
mmcblk0 179:0 0 29.2G 0 disk
|-mmcblk0p4 179:4 0 4G 0 part
|-mmcblk0p2 179:2 0 500M 0 part /boot
|-mmcblk0p3 179:3 0 256M 0 part [SWAP]
`-mmcblk0p1 179:1 0 256M 0 part /boot/efi
btrfs fi show /
Label: none uuid: 07892354-ddaa-4443-90ea-f76a06accaba
Total devices 1 FS bytes used 1.40GiB
devid 1 size 4.00GiB used 3.00GiB path /dev/sda4
The bug is quite nasty that you can't either unmount /dev/sda4 or
/dev/mmcblk0p4. And the problem does not get solved until you take
the sda out of the system on to another system to change its fsid using
the 'btrfstune -u' command.
Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
Looks like that the test will break the whole test env as it leaves an
unmountable $SCRATCH_MNT. I'd wait for the fix to get in first before
merging the test, in case it breaks normal regression tests. (I noticed
that the test is not in 'auto' group, so it's not that dangerous.)
Its possible that its unmountable without the kernel patch. But I am
unable to reproduce it consistently with or without the kernel patch.
Any idea ways to make it auto for kernels without the patch?
Also, it'd be great if test can be reviewed by btrfs folks too!
---
tests/btrfs/173 | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++
tests/btrfs/173.out | 5 ++++
tests/btrfs/group | 1 +
3 files changed, 78 insertions(+)
create mode 100755 tests/btrfs/173
create mode 100644 tests/btrfs/173.out
diff --git a/tests/btrfs/173 b/tests/btrfs/173
new file mode 100755
index 000000000000..f59a62e206c3
--- /dev/null
+++ b/tests/btrfs/173
@@ -0,0 +1,72 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2018 Oracle. All Rights Reserved.
+#
+# FS QA Test 173
+#
+# Fuzzy test for FS image duplication.
+# Could be fixed by
+# [patch] btrfs: harden agaist duplicate fsid
+#
+seq=`basename $0`
+seqres=$RESULT_DIR/$seq
+echo "QA output created by $seq"
+
+here=`pwd`
+tmp=/tmp/$$
+status=1 # failure is the default!
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+_cleanup()
+{
+ cd /
+ rm -f $tmp.*
+}
+
+# get standard environment, filters and checks
+. ./common/rc
+. ./common/filter
+
+# remove previous $seqres.full before test
+rm -f $seqres.full
+
+# real QA test starts here
+
+# Modify as appropriate.
+_supported_fs btrfs
+_supported_os Linux
+_require_scratch_dev_pool 2
+_scratch_dev_pool_get 2
+
+dev_foo=$(echo $SCRATCH_DEV_POOL | awk '{print $1}' | rev | cut -d"/" -f1 | rev)
+dev_bar=$(echo $SCRATCH_DEV_POOL | awk '{print $2}' | rev | cut -d"/" -f1 | rev)
This doesn't work if the devices in SCRATCH_DEV_POOL are symlinks, e.g.
lvm devices: /dev/mapper/testvg-testlv1, dev_foo is "testvg-testlv1" in
this case.
Ah, right will fix.
+
+_mkfs_dev /dev/$dev_foo
But /dev/testvg-testlv1 isn't existed.
_short_dev and/or _real_dev is useful in this case. e.g.
dev_foo=$(echo $SCRATCH_DEV_POOL | awk '{print $1}')
# dev_foo is like "dm-1"
dev_foo=$(_short_dev $dev_foo)
# dev_foo is like "/dev/dm-1"
dev_foo=$(_real_dev $dev_foo)
I changed the code a bit which avoids the split. Pls review if that
will be ok.
+_mount /dev/$dev_foo $SCRATCH_MNT
It'd better to mount non-SCRATCH_DEV to other mount point, e.g.
$TEST_DIR/$seq.mnt
Will do, any idea why? Isn't the framework automatically try to
unmount SCRATCH_MNT.
Thanks, Anand
Thanks,
Eryu
+
+echo mount before btrfs image clone | tee -a $seqres.full
+findmnt /dev/$dev_foo | grep -v TARGET | awk '{print $1" "$2}' | \
+ sed -e "s/$dev_foo/dev_foo/g" | _filter_scratch | tee -a $seqres.full
+findmnt /dev/$dev_bar | grep -v TARGET | awk '{print $1" "$2}' | \
+ sed -e "s/$dev_bar/dev_bar/g" | _filter_scratch | tee -a $seqres.full
+
+for sb_bytenr in 65536 67108864
+do
+ echo -n "dd status=none if=/dev/$dev_foo of=/dev/$dev_bar bs=1 "\
+ "seek=$sb_bytenr skip=$sb_bytenr count=4096" >> $seqres.full
+ dd status=none if=/dev/$dev_foo of=/dev/$dev_bar bs=1 seek=$sb_bytenr \
+ skip=$sb_bytenr count=4096 >> $seqres.full 2>&1
+ echo ..:$? >> $seqres.full
+done
+
+echo mount after btrfs image clone | tee -a $seqres.full
+findmnt /dev/$dev_foo | grep -v TARGET | awk '{print $1" "$2}' | \
+ sed -e "s/$dev_foo/dev_foo/g" | _filter_scratch | tee -a $seqres.full
+findmnt /dev/$dev_bar | grep -v TARGET | awk '{print $1" "$2}' | \
+ sed -e "s/$dev_bar/dev_bar/g" | _filter_scratch | tee -a $seqres.full
+
+_scratch_dev_pool_put
+
+# success, all done
+status=0
+exit
diff --git a/tests/btrfs/173.out b/tests/btrfs/173.out
new file mode 100644
index 000000000000..a2ef7a26f4b9
--- /dev/null
+++ b/tests/btrfs/173.out
@@ -0,0 +1,5 @@
+QA output created by 173
+mount before btrfs image clone
+SCRATCH_MNT /dev/dev_foo
+mount after btrfs image clone
+SCRATCH_MNT /dev/dev_foo
diff --git a/tests/btrfs/group b/tests/btrfs/group
index 45782565c3b7..b2f1393f3e97 100644
--- a/tests/btrfs/group
+++ b/tests/btrfs/group
@@ -175,3 +175,4 @@
170 auto quick snapshot
171 auto quick qgroup
172 auto quick punch
+173 volume
--
1.8.3.1
