On 2017年12月05日 18:04, Nikolay Borisov wrote: > > > On 5.12.2017 11:33, Qu Wenruo wrote: >> >> >> On 2017年12月05日 16:39, Nikolay Borisov wrote: >>> This functionality regressed some time ago and it was never caught. Seems no >>> one complained of that, but to be sure add a regression test to prevent >>> future >>> regressions. >>> >>> Signed-off-by: Nikolay Borisov <nbori...@suse.com> >> >> One nitpick for the patch sequence, normally we put fix before test >> case, to avoid breaking bisect. >> >>> --- >>> tests/fsck-tests/029-superblock-recovery/test.sh | 64 >>> ++++++++++++++++++++++++ >>> 1 file changed, 64 insertions(+) >>> create mode 100755 tests/fsck-tests/029-superblock-recovery/test.sh >>> >>> diff --git a/tests/fsck-tests/029-superblock-recovery/test.sh >>> b/tests/fsck-tests/029-superblock-recovery/test.sh >>> new file mode 100755 >>> index 000000000000..beb78d6ccc22 >>> --- /dev/null >>> +++ b/tests/fsck-tests/029-superblock-recovery/test.sh >>> @@ -0,0 +1,64 @@ >>> +#!/bin/bash >>> +# Test that any superblock is correctly detected >>> +# and fixed by btrfs rescue >>> + >>> +source "$TOP/tests/common" >>> + >>> +check_prereq btrfs >>> +check_prereq mkfs.btrfs >>> +check_prereq btrfs-select-super >>> + >>> +setup_root_helper >>> + >>> +rm -f dev1 >>> +run_check truncate -s 260G dev1 >>> +loop=$(run_check_stdout $SUDO_HELPER losetup --find --show dev1) >> >> We have function to do it already. >> prepare_test_dev will use loopback device as fallback if $TEST_DEV is >> not specified. >> Tt can handle size well, and it also uses sparse file so no need to >> worry about disk usage. > > Then the test suite is not very consistent, since I copied this loopback > handling from some other test.
The same feeling when I am pointed that something can be replaced by
wrappers in fstests.
Some of them can be cleaned up later.
>
>>
>>> +
>>> +# Create the test file system.
>>> +run_check $SUDO_HELPER "$TOP"/mkfs.btrfs -f "$loop"
>>> +
>>> +function check_corruption {
>>> + local sb_offset=$1
>>> + local source_sb=$2
>>> +
>>> +
>>> + # First we ensure we can mount it successfully
>>> + run_check $SUDO_HELPER mount $loop "$TEST_MNT"
>>> + run_check $SUDO_HELPER umount "$TEST_MNT"
>>> +
>>> + # Now corrupt 1k of the superblock at sb_offset
>>> + run_check $SUDO_HELPER dd bs=1K count=1 seek=$(($sb_offset + 1))
>>> if=/dev/zero of="$loop"
>>> +
>>> + #if corrupting one of the sb copies, copy it over the initial superblock
>>> + if [ ! -z $source_sb ]; then
>>> + local shift_val=$((16 << $source_sb * 12 ))
>>> + run_check $SUDO_HELPER dd bs=1K count=4 seek=64 skip=$shift_val
>>> if="$loop" of="$loop"
>>> + fi
>>
>> Personally speaking, corrupt 64K (1st super) then corrupt the desired
>> copy could make the function easier.
>> Although we need to split the check part from this function, resulting
>> something like:
>>
>> corrupt_super 64k
>> corrupt_super 64m
>> check_super_recover
> I'm reluctant to change this function any more. It has comments on all
> logical steps and is self-contained and I'd rather keep it that way.
>
>>
>>> +
>>> + run_mustfail "Mounted fs with corrupted superblock" \
>>> + $SUDO_HELPER mount $loop "$TEST_MNT"
>>> +
>>> + # Now run btrfs rescue which should fix the superblock. It uses 2
>>> + # to signal success of recovery use mayfail to ignore that retval
>>> + # but still log the output of the command
>>> + run_mayfail $SUDO_HELPER "$TOP"/btrfs rescue super-recover -yv "$loop"
>>> + if [ $? != 2 ]; then
>>> + _fail "couldn't rescue super"
>>> + fi
>>
>> It's understandable to have return value other than 0 to distinguish
>> health fs from repairable fs.
>> But at least let's also put this into man page.
>
> Yeah, tell me about it, super recovery actually has 5 return values:
>
> 7985fe64e0e2 ("Btrfs-progs: add super-recover to recover bad supers")
>
> There will be five kinds of return values:
>
> 0: all supers are valid, no need to recover
> 1: usage or syntax error
> 2: recover all bad superblocks successfully
> 3: fail to recover bad superblocks
> 4: abort to recover bad superblocks
Since we all agree that the return value is a messy,
maybe we could just simplify it to 0 (all valid or successful recover)
and 1 (the rest)?
Thanks,
Qu
>
>
>>
>> Thanks,
>> Qu
>>
>>> +
>>> + run_check $SUDO_HELPER mount $loop "$TEST_MNT"
>>> + run_check $SUDO_HELPER umount "$TEST_MNT"
>>> +}
>>> +
>>> +_log "Corrupting first superblock"
>>> +check_corruption 64
>>> +
>>> +_log "Corrupting second superblock"
>>> +check_corruption 65536 1
>>> +
>>> +_log "Corrupting third superblock"
>>> +check_corruption 268435456 2
>>> +
>>> +# Cleanup
>>> +run_check $SUDO_HELPER losetup -d "$loop"
>>> +rm -f dev1
>>>
>>
> --
> 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
>
signature.asc
Description: OpenPGP digital signature
