Please describe the problem.

ATM I am chasing a problem that somehow one key "mutated" although I do not remember doing anything malicious, file seems to be also not writable (itself). So I decided to fsck, and only spotted a problem when some warnings started to appear that I am not the owner of the (key)file. So I looked inside and found that all key dirs are writeable BUT annex complains only about the ones where it can't change permissions since they don't belong to me

What version of git-annex are you using? On what operating system?

6.20170815+gitg22da64d0f-1~ndall+1

Please provide any additional information below.

$> for f in sub00{1,3}/anatomy/highres001.nii.gz; do ls -ld $(realpath $f | xargs dirname ); git annex fsck $f; done 
drwxrws--- 2 yoh famface 3 May 12 15:15 /data/famface/openfmri/data/.git/annex/objects/08/V3/SHA256E-s6498717--b850ac82ec9db2d399962609e9381d9c2bdf1f426012500b7005b173ea4d9102.nii.gz/
fsck sub001/anatomy/highres001.nii.gz (checksum...) ok
(recording state in git...)
drwxrwsr-x 2 contematto famface 3 Jul 13  2015 /data/famface/openfmri/data/.git/annex/objects/x2/xX/SHA256E-s6592524--dccba651dc4cd104826a05a2efb6a257b39ca2d8b44d215027250221729f9434.nii.gz/
fsck sub003/anatomy/highres001.nii.gz 
  ** Unable to set correct write mode for .git/annex/objects/x2/xX/SHA256E-s6592524--dccba651dc4cd104826a05a2efb6a257b39ca2d8b44d215027250221729f9434.nii.gz/SHA256E-s6592524--dccba651dc4cd104826a05a2efb6a257b39ca2d8b44d215027250221729f9434.nii.gz ; perhaps you don't own that file
(checksum...) ok
(recording state in git...)

# thought to see may be annex would complain then!?
$> chmod a+rwx /data/famface/openfmri/data/.git/annex/objects/08/V3/SHA256E-s6498717--b850ac82ec9db2d399962609e9381d9c2bdf1f426012500b7005b173ea4d9102.nii.gz/

$> for f in sub00{1,3}/anatomy/highres001.nii.gz; do ls -ld $(realpath $f | xargs dirname ); git annex fsck $f; done                                          
drwxrwsrwx 2 yoh famface 3 May 12 15:15 /data/famface/openfmri/data/.git/annex/objects/08/V3/SHA256E-s6498717--b850ac82ec9db2d399962609e9381d9c2bdf1f426012500b7005b173ea4d9102.nii.gz/
fsck sub001/anatomy/highres001.nii.gz (checksum...) ok
(recording state in git...)
drwxrwsr-x 2 contematto famface 3 Jul 13  2015 /data/famface/openfmri/data/.git/annex/objects/x2/xX/SHA256E-s6592524--dccba651dc4cd104826a05a2efb6a257b39ca2d8b44d215027250221729f9434.nii.gz/
fsck sub003/anatomy/highres001.nii.gz 
  ** Unable to set correct write mode for .git/annex/objects/x2/xX/SHA256E-s6592524--dccba651dc4cd104826a05a2efb6a257b39ca2d8b44d215027250221729f9434.nii.gz/SHA256E-s6592524--dccba651dc4cd104826a05a2efb6a257b39ca2d8b44d215027250221729f9434.nii.gz ; perhaps you don't own that file
(checksum...) ok
(recording state in git...)

btw -- the same wrong permissions on the upper hash directories, and they do not get fixed/complained about at all (that is ok)