[PATCH] generic/631: Add a check for extended attributes

[PATCH] generic/631: Add a check for extended attributes

[Shreeya Patel]

Test case 631 fails for filesystems like exfat or vfat or any other
which does not support extended attributes.

The main reason for failure is not being able to mount overlayfs
with filesystems that do not support extended attributes.
mount -t overlay overlay -o "$l,$u,$w,$i" $mergedir

Above command would return an error as -
/var/mnt/scratch/merged0: wrong fs type, bad option, bad superblock on overlay,
missing codepage or helper program, or other error.

dmesg log reports the following -
overlayfs: filesystem on '/var/mnt/scratch/upperdir1' not supported

As per the overlayfs documentation -
"A wide range of filesystems supported by Linux can be the lower filesystem,
but not all filesystems that are mountable by Linux have the features needed
for OverlayFS to work. The lower filesystem does not need to be writable.
The lower filesystem can even be another overlayfs.
The upper filesystem will normally be writable and if it is it must support
the creation of trusted.* and/or user.* extended attributes, and must provide
valid d_type in readdir responses, so NFS is not suitable.
A read-only overlay of two read-only filesystems may use any filesystem type."

As per the above statements from the overlayfs documentation, it is clear that
filesystems that do not support extended attributes would not work with overlayfs.
This is why we see the error in dmesg log for upperdir1 which had an exfat filesystem.

Hence, add a check for extended attributes which would avoid running this tests for
filesystems that are not supported.

Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
---
 tests/generic/631 | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tests/generic/631 b/tests/generic/631
index c43f3de3..c7f0190e 100755
--- a/tests/generic/631
+++ b/tests/generic/631
@@ -39,10 +39,12 @@ _cleanup()
 
 # get standard environment, filters and checks
 . ./common/rc
+. ./common/attr
 
 # real QA test starts here
 _supported_fs generic
 _require_scratch
+_require_attrs
 test "$FSTYP" = "overlay" && _notrun "Test does not apply to overlayfs."
 _require_extra_fs overlay
 
-- 
2.30.2

Re: [PATCH] generic/631: Add a check for extended attributes

[Darrick J. Wong]

On Fri, Apr 30, 2021 at 03:56:56PM +0530, Shreeya Patel wrote:
> Test case 631 fails for filesystems like exfat or vfat or any other
> which does not support extended attributes.
> 
> The main reason for failure is not being able to mount overlayfs
> with filesystems that do not support extended attributes.
> mount -t overlay overlay -o "$l,$u,$w,$i" $mergedir
> 
> Above command would return an error as -
> /var/mnt/scratch/merged0: wrong fs type, bad option, bad superblock on overlay,
> missing codepage or helper program, or other error.
> 
> dmesg log reports the following -
> overlayfs: filesystem on '/var/mnt/scratch/upperdir1' not supported
> 
> As per the overlayfs documentation -
> "A wide range of filesystems supported by Linux can be the lower filesystem,
> but not all filesystems that are mountable by Linux have the features needed
> for OverlayFS to work. The lower filesystem does not need to be writable.
> The lower filesystem can even be another overlayfs.
> The upper filesystem will normally be writable and if it is it must support
> the creation of trusted.* and/or user.* extended attributes, and must provide
> valid d_type in readdir responses, so NFS is not suitable.

Does this test also need to check for d_type support?

> A read-only overlay of two read-only filesystems may use any filesystem type."
> 
> As per the above statements from the overlayfs documentation, it is clear that
> filesystems that do not support extended attributes would not work with overlayfs.
> This is why we see the error in dmesg log for upperdir1 which had an exfat filesystem.

(Please wrap the commit messages at 75 columns, per SubmittingPatches.)

> Hence, add a check for extended attributes which would avoid running this tests for
> filesystems that are not supported.
> 
> Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>

Regardless, this seems like a reasonable change, so:

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  tests/generic/631 | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/tests/generic/631 b/tests/generic/631
> index c43f3de3..c7f0190e 100755
> --- a/tests/generic/631
> +++ b/tests/generic/631
> @@ -39,10 +39,12 @@ _cleanup()
>  
>  # get standard environment, filters and checks
>  . ./common/rc
> +. ./common/attr
>  
>  # real QA test starts here
>  _supported_fs generic
>  _require_scratch
> +_require_attrs
>  test "$FSTYP" = "overlay" && _notrun "Test does not apply to overlayfs."
>  _require_extra_fs overlay
>  
> -- 
> 2.30.2
> 

Re: [PATCH] generic/631: Add a check for extended attributes

[Shreeya Patel]

On 30/04/21 8:47 pm, Darrick J. Wong wrote:
> On Fri, Apr 30, 2021 at 03:56:56PM +0530, Shreeya Patel wrote:
>> Test case 631 fails for filesystems like exfat or vfat or any other
>> which does not support extended attributes.
>>
>> The main reason for failure is not being able to mount overlayfs
>> with filesystems that do not support extended attributes.
>> mount -t overlay overlay -o "$l,$u,$w,$i" $mergedir
>>
>> Above command would return an error as -
>> /var/mnt/scratch/merged0: wrong fs type, bad option, bad superblock on overlay,
>> missing codepage or helper program, or other error.
>>
>> dmesg log reports the following -
>> overlayfs: filesystem on '/var/mnt/scratch/upperdir1' not supported
>>
>> As per the overlayfs documentation -
>> "A wide range of filesystems supported by Linux can be the lower filesystem,
>> but not all filesystems that are mountable by Linux have the features needed
>> for OverlayFS to work. The lower filesystem does not need to be writable.
>> The lower filesystem can even be another overlayfs.
>> The upper filesystem will normally be writable and if it is it must support
>> the creation of trusted.* and/or user.* extended attributes, and must provide
>> valid d_type in readdir responses, so NFS is not suitable.
> Does this test also need to check for d_type support?


It already does that.


>> A read-only overlay of two read-only filesystems may use any filesystem type."
>>
>> As per the above statements from the overlayfs documentation, it is clear that
>> filesystems that do not support extended attributes would not work with overlayfs.
>> This is why we see the error in dmesg log for upperdir1 which had an exfat filesystem.
> (Please wrap the commit messages at 75 columns, per SubmittingPatches.)


Sure, will send a v2.


>> Hence, add a check for extended attributes which would avoid running this tests for
>> filesystems that are not supported.
>>
>> Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
> Regardless, this seems like a reasonable change, so:
>
> Reviewed-by: Darrick J. Wong <djwong@kernel.org>


Thanks


> --D
>
>> ---
>>   tests/generic/631 | 2 ++
>>   1 file changed, 2 insertions(+)
>>
>> diff --git a/tests/generic/631 b/tests/generic/631
>> index c43f3de3..c7f0190e 100755
>> --- a/tests/generic/631
>> +++ b/tests/generic/631
>> @@ -39,10 +39,12 @@ _cleanup()
>>   
>>   # get standard environment, filters and checks
>>   . ./common/rc
>> +. ./common/attr
>>   
>>   # real QA test starts here
>>   _supported_fs generic
>>   _require_scratch
>> +_require_attrs
>>   test "$FSTYP" = "overlay" && _notrun "Test does not apply to overlayfs."
>>   _require_extra_fs overlay
>>   
>> -- 
>> 2.30.2
>>