diff mbox

[1/3] btrfs: Add incompat flags check for btrfs_check_super_valid()

Message ID 20180419093816.888-1-wqu@suse.com (mailing list archive)
State New, archived
Headers show

Commit Message

Qu Wenruo April 19, 2018, 9:38 a.m. UTC
Although we have already checked incompat flags manually before really
mounting it, we could still enhance btrfs_check_super_valid() to check
incompat flags for later write time super block validation check.

This patch adds such incompat flags check for btrfs_check_super_valid(),
currently it won't be triggered, but provides the basis for later write
time check.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/disk-io.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

Comments

Nikolay Borisov April 19, 2018, 10:59 a.m. UTC | #1
On 19.04.2018 12:38, Qu Wenruo wrote:
> Although we have already checked incompat flags manually before really
> mounting it, we could still enhance btrfs_check_super_valid() to check
> incompat flags for later write time super block validation check.
> 
> This patch adds such incompat flags check for btrfs_check_super_valid(),
> currently it won't be triggered, but provides the basis for later write
> time check.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>

> ---
>  fs/btrfs/disk-io.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 60caa68c3618..ec123158f051 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)

nit: Thinking out loud here - wouldn't it make more sense to name the
function btrfs_validate_super. check_super_valid sounds a bit cumbersome
to me. What do you think ?
>  		ret = -EINVAL;
>  	}
>  
> +	/*
> +	 * Before calling btrfs_check_super_valid() we have already checked
> +	 * incompat flags. So if we developr new incompat flags, it's must be
s/developr/detect ?
> +	 * some corruption.
> +	 */
> +	if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
> +		btrfs_err(fs_info,
> +		"corrupted incompat flags detected 0x%llx, supported 0x%llx",
> +			  btrfs_super_incompat_flags(sb),
> +			  BTRFS_FEATURE_INCOMPAT_SUPP);
> +		ret = -EINVAL;
> +	}
> +
>  	/*
>  	 * The generation is a global counter, we'll trust it more than the others
>  	 * but it's still possible that it's the one that's wrong.
> 
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Qu Wenruo April 19, 2018, 11:10 a.m. UTC | #2
On 2018年04月19日 18:59, Nikolay Borisov wrote:
> 
> 
> On 19.04.2018 12:38, Qu Wenruo wrote:
>> Although we have already checked incompat flags manually before really
>> mounting it, we could still enhance btrfs_check_super_valid() to check
>> incompat flags for later write time super block validation check.
>>
>> This patch adds such incompat flags check for btrfs_check_super_valid(),
>> currently it won't be triggered, but provides the basis for later write
>> time check.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
> 
> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> 
>> ---
>>  fs/btrfs/disk-io.c | 13 +++++++++++++
>>  1 file changed, 13 insertions(+)
>>
>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>> index 60caa68c3618..ec123158f051 100644
>> --- a/fs/btrfs/disk-io.c
>> +++ b/fs/btrfs/disk-io.c
>> @@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)
> 
> nit: Thinking out loud here - wouldn't it make more sense to name the
> function btrfs_validate_super. check_super_valid sounds a bit cumbersome
> to me. What do you think ?

Indeed, I also like to remove the btrfs_ prefix since it's a static
function.
validate_super() looks much better.

Thanks,
Qu

>>  		ret = -EINVAL;
>>  	}
>>  
>> +	/*
>> +	 * Before calling btrfs_check_super_valid() we have already checked
>> +	 * incompat flags. So if we developr new incompat flags, it's must be
> s/developr/detect ?
>> +	 * some corruption.
>> +	 */
>> +	if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
>> +		btrfs_err(fs_info,
>> +		"corrupted incompat flags detected 0x%llx, supported 0x%llx",
>> +			  btrfs_super_incompat_flags(sb),
>> +			  BTRFS_FEATURE_INCOMPAT_SUPP);
>> +		ret = -EINVAL;
>> +	}
>> +
>>  	/*
>>  	 * The generation is a global counter, we'll trust it more than the others
>>  	 * but it's still possible that it's the one that's wrong.
>>
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David Sterba April 19, 2018, 3:31 p.m. UTC | #3
On Thu, Apr 19, 2018 at 07:10:30PM +0800, Qu Wenruo wrote:
> 
> 
> On 2018年04月19日 18:59, Nikolay Borisov wrote:
> > 
> > 
> > On 19.04.2018 12:38, Qu Wenruo wrote:
> >> Although we have already checked incompat flags manually before really
> >> mounting it, we could still enhance btrfs_check_super_valid() to check
> >> incompat flags for later write time super block validation check.
> >>
> >> This patch adds such incompat flags check for btrfs_check_super_valid(),
> >> currently it won't be triggered, but provides the basis for later write
> >> time check.
> >>
> >> Signed-off-by: Qu Wenruo <wqu@suse.com>
> > 
> > Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> > 
> >> ---
> >>  fs/btrfs/disk-io.c | 13 +++++++++++++
> >>  1 file changed, 13 insertions(+)
> >>
> >> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> >> index 60caa68c3618..ec123158f051 100644
> >> --- a/fs/btrfs/disk-io.c
> >> +++ b/fs/btrfs/disk-io.c
> >> @@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)
> > 
> > nit: Thinking out loud here - wouldn't it make more sense to name the
> > function btrfs_validate_super. check_super_valid sounds a bit cumbersome
> > to me. What do you think ?
> 
> Indeed, I also like to remove the btrfs_ prefix since it's a static
> function.
> validate_super() looks much better.

It's not necessary to remove the btrfs_ prefix from all static
functions, sometimes the functions appear on stacks or mixed with other
subystem helpers that have generic names. The prefix makes it clear that
it's our function.
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Nikolay Borisov April 19, 2018, 4:24 p.m. UTC | #4
On 19.04.2018 18:31, David Sterba wrote:
> On Thu, Apr 19, 2018 at 07:10:30PM +0800, Qu Wenruo wrote:
>>
>>
>> On 2018年04月19日 18:59, Nikolay Borisov wrote:
>>>
>>>
>>> On 19.04.2018 12:38, Qu Wenruo wrote:
>>>> Although we have already checked incompat flags manually before really
>>>> mounting it, we could still enhance btrfs_check_super_valid() to check
>>>> incompat flags for later write time super block validation check.
>>>>
>>>> This patch adds such incompat flags check for btrfs_check_super_valid(),
>>>> currently it won't be triggered, but provides the basis for later write
>>>> time check.
>>>>
>>>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>>>
>>> Reviewed-by: Nikolay Borisov <nborisov@suse.com>
>>>
>>>> ---
>>>>  fs/btrfs/disk-io.c | 13 +++++++++++++
>>>>  1 file changed, 13 insertions(+)
>>>>
>>>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>>>> index 60caa68c3618..ec123158f051 100644
>>>> --- a/fs/btrfs/disk-io.c
>>>> +++ b/fs/btrfs/disk-io.c
>>>> @@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)
>>>
>>> nit: Thinking out loud here - wouldn't it make more sense to name the
>>> function btrfs_validate_super. check_super_valid sounds a bit cumbersome
>>> to me. What do you think ?
>>
>> Indeed, I also like to remove the btrfs_ prefix since it's a static
>> function.
>> validate_super() looks much better.
> 
> It's not necessary to remove the btrfs_ prefix from all static
> functions, sometimes the functions appear on stacks or mixed with other
> subystem helpers that have generic names. The prefix makes it clear that
> it's our function.

I agree with David, just make it btrfs_validate_super
> 
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David Sterba April 20, 2018, 1:04 p.m. UTC | #5
On Thu, Apr 19, 2018 at 07:24:48PM +0300, Nikolay Borisov wrote:
> I agree with David, just make it btrfs_validate_super

Ack.
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Anand Jain April 20, 2018, 2:32 p.m. UTC | #6
On 04/19/2018 05:38 PM, Qu Wenruo wrote:
> Although we have already checked incompat flags manually before really
> mounting it, we could still enhance btrfs_check_super_valid() to check
> incompat flags for later write time super block validation check.
> 
> This patch adds such incompat flags check for btrfs_check_super_valid(),
> currently it won't be triggered, but provides the basis for later write
> time check.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>   fs/btrfs/disk-io.c | 13 +++++++++++++
>   1 file changed, 13 insertions(+)
> 
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 60caa68c3618..ec123158f051 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)
>   		ret = -EINVAL;
>   	}
>   
> +	/*
> +	 * Before calling btrfs_check_super_valid() we have already checked
> +	 * incompat flags. So if we developr new incompat flags, it's must be
> +	 * some corruption.
> +	 */
> +	if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
> +		btrfs_err(fs_info,
> +		"corrupted incompat flags detected 0x%llx, supported 0x%llx",
> +			  btrfs_super_incompat_flags(sb),
> +			  BTRFS_FEATURE_INCOMPAT_SUPP);
> +		ret = -EINVAL;
> +	}
> +
>   	/*
>   	 * The generation is a global counter, we'll trust it more than the others
>   	 * but it's still possible that it's the one that's wrong.
> 

This patch should move the existing check in the open_ctree() line 2707
into the btrfs_check_super_valid(), we don't need duplicate checks.

disk-io.c

2707         features = btrfs_super_incompat_flags(disk_super) &
2708                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2709         if (features) {
2710                 btrfs_err(fs_info,
2711                     "cannot mount because of unsupported optional 
features (%llx)",
2712                     features);
2713                 err = -EINVAL;
2714                 goto fail_alloc;
2715         }


Thanks, Anand
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David Sterba April 20, 2018, 3:15 p.m. UTC | #7
On Fri, Apr 20, 2018 at 10:32:03PM +0800, Anand Jain wrote:
> 
> 
> On 04/19/2018 05:38 PM, Qu Wenruo wrote:
> > Although we have already checked incompat flags manually before really
> > mounting it, we could still enhance btrfs_check_super_valid() to check
> > incompat flags for later write time super block validation check.
> > 
> > This patch adds such incompat flags check for btrfs_check_super_valid(),
> > currently it won't be triggered, but provides the basis for later write
> > time check.
> > 
> > Signed-off-by: Qu Wenruo <wqu@suse.com>
> > ---
> >   fs/btrfs/disk-io.c | 13 +++++++++++++
> >   1 file changed, 13 insertions(+)
> > 
> > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> > index 60caa68c3618..ec123158f051 100644
> > --- a/fs/btrfs/disk-io.c
> > +++ b/fs/btrfs/disk-io.c
> > @@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)
> >   		ret = -EINVAL;
> >   	}
> >   
> > +	/*
> > +	 * Before calling btrfs_check_super_valid() we have already checked
> > +	 * incompat flags. So if we developr new incompat flags, it's must be
> > +	 * some corruption.
> > +	 */
> > +	if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
> > +		btrfs_err(fs_info,
> > +		"corrupted incompat flags detected 0x%llx, supported 0x%llx",

> 2707         features = btrfs_super_incompat_flags(disk_super) &
> 2708                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
> 2709         if (features) {
> 2710                 btrfs_err(fs_info,
> 2711                     "cannot mount because of unsupported optional features (%llx)",
> 2712                     features);
> 2713                 err = -EINVAL;
> 2714                 goto fail_alloc;
> 2715         }

So there's a "user experience" change, now that you pointed out the
other check. If a filesystem with incompat bits set will be mounted,
this will say 'you have corrupted filesystem', which is not IMO what we
want to tell.

Tough the extended btrfs_check_super_valid could catch the corrupted
incompat bits, what we need at mount time is wording from the 2nd
message ("cannot mount unsuppported features").

I think that there should be a separate function that does the
pre-commit checks, calls btrfs_check_super_valid and also validates the
incompat bit.
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Anand Jain April 21, 2018, 2:38 a.m. UTC | #8
On 04/20/2018 11:15 PM, David Sterba wrote:
> On Fri, Apr 20, 2018 at 10:32:03PM +0800, Anand Jain wrote:
>>
>>
>> On 04/19/2018 05:38 PM, Qu Wenruo wrote:
>>> Although we have already checked incompat flags manually before really
>>> mounting it, we could still enhance btrfs_check_super_valid() to check
>>> incompat flags for later write time super block validation check.
>>>
>>> This patch adds such incompat flags check for btrfs_check_super_valid(),
>>> currently it won't be triggered, but provides the basis for later write
>>> time check.
>>>
>>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>>> ---
>>>    fs/btrfs/disk-io.c | 13 +++++++++++++
>>>    1 file changed, 13 insertions(+)
>>>
>>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>>> index 60caa68c3618..ec123158f051 100644
>>> --- a/fs/btrfs/disk-io.c
>>> +++ b/fs/btrfs/disk-io.c
>>> @@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)
>>>    		ret = -EINVAL;
>>>    	}
>>>    
>>> +	/*
>>> +	 * Before calling btrfs_check_super_valid() we have already checked
>>> +	 * incompat flags. So if we developr new incompat flags, it's must be
>>> +	 * some corruption.
>>> +	 */
>>> +	if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
>>> +		btrfs_err(fs_info,
>>> +		"corrupted incompat flags detected 0x%llx, supported 0x%llx",
> 
>> 2707         features = btrfs_super_incompat_flags(disk_super) &
>> 2708                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
>> 2709         if (features) {
>> 2710                 btrfs_err(fs_info,
>> 2711                     "cannot mount because of unsupported optional features (%llx)",
>> 2712                     features);
>> 2713                 err = -EINVAL;
>> 2714                 goto fail_alloc;
>> 2715         }
> 
> So there's a "user experience" change, now that you pointed out the
> other check. 

  Its a regression.

> If a filesystem with incompat bits set will be mounted,
> this will say 'you have corrupted filesystem', which is not IMO what we
> want to tell.
> 
> Tough the extended btrfs_check_super_valid could catch the corrupted
> incompat bits, what we need at mount time is wording from the 2nd
> message ("cannot mount unsuppported features").
> 
> I think that there should be a separate function that does the
> pre-commit checks, calls btrfs_check_super_valid and also validates the
> incompat bit.

  We can still print it as 'unsupported optional features', which would
  imply corruption in the non-mount context.

Thanks, Anand

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Qu Wenruo April 21, 2018, 2:43 a.m. UTC | #9
On 2018年04月21日 10:38, Anand Jain wrote:
> 
> 
> On 04/20/2018 11:15 PM, David Sterba wrote:
>> On Fri, Apr 20, 2018 at 10:32:03PM +0800, Anand Jain wrote:
>>>
>>>
>>> On 04/19/2018 05:38 PM, Qu Wenruo wrote:
>>>> Although we have already checked incompat flags manually before really
>>>> mounting it, we could still enhance btrfs_check_super_valid() to check
>>>> incompat flags for later write time super block validation check.
>>>>
>>>> This patch adds such incompat flags check for
>>>> btrfs_check_super_valid(),
>>>> currently it won't be triggered, but provides the basis for later write
>>>> time check.
>>>>
>>>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>>>> ---
>>>>    fs/btrfs/disk-io.c | 13 +++++++++++++
>>>>    1 file changed, 13 insertions(+)
>>>>
>>>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>>>> index 60caa68c3618..ec123158f051 100644
>>>> --- a/fs/btrfs/disk-io.c
>>>> +++ b/fs/btrfs/disk-io.c
>>>> @@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct
>>>> btrfs_fs_info *fs_info)
>>>>            ret = -EINVAL;
>>>>        }
>>>>    +    /*
>>>> +     * Before calling btrfs_check_super_valid() we have already
>>>> checked
>>>> +     * incompat flags. So if we developr new incompat flags, it's
>>>> must be
>>>> +     * some corruption.
>>>> +     */
>>>> +    if (btrfs_super_incompat_flags(sb) &
>>>> ~BTRFS_FEATURE_INCOMPAT_SUPP) {
>>>> +        btrfs_err(fs_info,
>>>> +        "corrupted incompat flags detected 0x%llx, supported 0x%llx",
>>
>>> 2707         features = btrfs_super_incompat_flags(disk_super) &
>>> 2708                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
>>> 2709         if (features) {
>>> 2710                 btrfs_err(fs_info,
>>> 2711                     "cannot mount because of unsupported
>>> optional features (%llx)",
>>> 2712                     features);
>>> 2713                 err = -EINVAL;
>>> 2714                 goto fail_alloc;
>>> 2715         }
>>
>> So there's a "user experience" change, now that you pointed out the
>> other check. 
> 
>  Its a regression.
> 
>> If a filesystem with incompat bits set will be mounted,
>> this will say 'you have corrupted filesystem', which is not IMO what we
>> want to tell.
>>
>> Tough the extended btrfs_check_super_valid could catch the corrupted
>> incompat bits, what we need at mount time is wording from the 2nd
>> message ("cannot mount unsuppported features").
>>
>> I think that there should be a separate function that does the
>> pre-commit checks, calls btrfs_check_super_valid and also validates the
>> incompat bit.
> 
>  We can still print it as 'unsupported optional features', which would
>  imply corruption in the non-mount context.

In that case such wording is not obvious enough to info it's super block
corruption.

So I still prefer current way of checking incompact flags and csum types
manually at mount time before btrfs_validate_super().

David's idea of a separate function to do mount time check and gives
better prompt is pretty good.
Especially for incompat features, as incompat features will increase in
the future and for older kernel info such feature as corruption is not
acceptable.

But currently, there are only 2 members we need to check at mount time
(csum_type and incompat features), and only one caller, current code
looks good enough for its purpose.

Thanks,
Qu

> 
> Thanks, Anand
> 
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Anand Jain April 21, 2018, 5:18 a.m. UTC | #10
On 04/21/2018 10:43 AM, Qu Wenruo wrote:
> 
> 
> On 2018年04月21日 10:38, Anand Jain wrote:
>>
>>
>> On 04/20/2018 11:15 PM, David Sterba wrote:
>>> On Fri, Apr 20, 2018 at 10:32:03PM +0800, Anand Jain wrote:
>>>>
>>>>
>>>> On 04/19/2018 05:38 PM, Qu Wenruo wrote:
>>>>> Although we have already checked incompat flags manually before really
>>>>> mounting it, we could still enhance btrfs_check_super_valid() to check
>>>>> incompat flags for later write time super block validation check.
>>>>>
>>>>> This patch adds such incompat flags check for
>>>>> btrfs_check_super_valid(),
>>>>> currently it won't be triggered, but provides the basis for later write
>>>>> time check.
>>>>>
>>>>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>>>>> ---
>>>>>     fs/btrfs/disk-io.c | 13 +++++++++++++
>>>>>     1 file changed, 13 insertions(+)
>>>>>
>>>>> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
>>>>> index 60caa68c3618..ec123158f051 100644
>>>>> --- a/fs/btrfs/disk-io.c
>>>>> +++ b/fs/btrfs/disk-io.c
>>>>> @@ -4104,6 +4104,19 @@ static int btrfs_check_super_valid(struct
>>>>> btrfs_fs_info *fs_info)
>>>>>             ret = -EINVAL;
>>>>>         }
>>>>>     +    /*
>>>>> +     * Before calling btrfs_check_super_valid() we have already
>>>>> checked
>>>>> +     * incompat flags. So if we developr new incompat flags, it's
>>>>> must be
>>>>> +     * some corruption.
>>>>> +     */
>>>>> +    if (btrfs_super_incompat_flags(sb) &
>>>>> ~BTRFS_FEATURE_INCOMPAT_SUPP) {
>>>>> +        btrfs_err(fs_info,
>>>>> +        "corrupted incompat flags detected 0x%llx, supported 0x%llx",
>>>
>>>> 2707         features = btrfs_super_incompat_flags(disk_super) &
>>>> 2708                 ~BTRFS_FEATURE_INCOMPAT_SUPP;
>>>> 2709         if (features) {
>>>> 2710                 btrfs_err(fs_info,
>>>> 2711                     "cannot mount because of unsupported
>>>> optional features (%llx)",
>>>> 2712                     features);
>>>> 2713                 err = -EINVAL;
>>>> 2714                 goto fail_alloc;
>>>> 2715         }
>>>
>>> So there's a "user experience" change, now that you pointed out the
>>> other check.
>>
>>   Its a regression.
>>
>>> If a filesystem with incompat bits set will be mounted,
>>> this will say 'you have corrupted filesystem', which is not IMO what we
>>> want to tell.
>>>
>>> Tough the extended btrfs_check_super_valid could catch the corrupted
>>> incompat bits, what we need at mount time is wording from the 2nd
>>> message ("cannot mount unsuppported features").
>>>
>>> I think that there should be a separate function that does the
>>> pre-commit checks, calls btrfs_check_super_valid and also validates the
>>> incompat bit.
>>
>>   We can still print it as 'unsupported optional features', which would
>>   imply corruption in the non-mount context.
> 
> In that case such wording is not obvious enough to info it's super block
> corruption.

  If the device is already mounted. Then its a corruption.

Thanks, Anand

> So I still prefer current way of checking incompact flags and csum types
> manually at mount time before btrfs_validate_super().
> 
> David's idea of a separate function to do mount time check and gives
> better prompt is pretty good.
> Especially for incompat features, as incompat features will increase in
> the future and for older kernel info such feature as corruption is not
> acceptable.
> 
> But currently, there are only 2 members we need to check at mount time
> (csum_type and incompat features), and only one caller, current code
> looks good enough for its purpose.
> 
> Thanks,
> Qu
> 
>>
>> Thanks, Anand
>>
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diff mbox

Patch

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 60caa68c3618..ec123158f051 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4104,6 +4104,19 @@  static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info)
 		ret = -EINVAL;
 	}
 
+	/*
+	 * Before calling btrfs_check_super_valid() we have already checked
+	 * incompat flags. So if we developr new incompat flags, it's must be
+	 * some corruption.
+	 */
+	if (btrfs_super_incompat_flags(sb) & ~BTRFS_FEATURE_INCOMPAT_SUPP) {
+		btrfs_err(fs_info,
+		"corrupted incompat flags detected 0x%llx, supported 0x%llx",
+			  btrfs_super_incompat_flags(sb),
+			  BTRFS_FEATURE_INCOMPAT_SUPP);
+		ret = -EINVAL;
+	}
+
 	/*
 	 * The generation is a global counter, we'll trust it more than the others
 	 * but it's still possible that it's the one that's wrong.