Miklos, This is the promised follow up to "fix corner case of non-unique st_dev;st_ino" that was merged to v5.5-rc2. The full details are available in the 1st posting of this patch set [1]. These patches have been tested with many different layer configurations using the tests in [2][3] among them also configurations of multi lower layer, where some lower fs are on safe fs as upper. Note that this patchset introduces a change of behavior for overlayfs. stat(2) on pure upper objects no longer report the real st_dev. Upper fs is now also assigned a pseudo dev number, like all lower fs and it is used when reporting stat(2) for pure upper objects as well as for objects on lower layer which uses the same fs as upper fs. These patches are also available on my github ovl-layers branch [4]. As mentioned before, I have a follow up series on branch ovl-ino [5] that fixes another rare case of st_dev;st_ino collision and some more improvements and fixes to xino. I still did not complete the tests for that follow up series. Thanks, Amir. Changes since v1: - "fix corner case of non-unique st_dev;st_ino" already merged - Replaced maxfsid notation with numfsid [1] https://marc.info/?l=linux-unionfs&m=157400544101251&w=2 [2] https://github.com/amir73il/xfstests/commits/ovl-nested [3] https://github.com/amir73il/unionmount-testsuite/commits/ovl-nested [4] https://github.com/amir73il/linux/commits/ovl-layers [5] https://github.com/amir73il/linux/commits/ovl-ino Amir Goldstein (5): ovl: generalize the lower_layers[] array ovl: simplify ovl_same_sb() helper ovl: generalize the lower_fs[] array ovl: fix corner case of conflicting lower layer uuid ovl: fix corner case of non-constant st_dev;st_ino fs/overlayfs/export.c | 6 +- fs/overlayfs/inode.c | 43 +++++--------- fs/overlayfs/namei.c | 10 ++-- fs/overlayfs/overlayfs.h | 23 ++++++- fs/overlayfs/ovl_entry.h | 15 +++-- fs/overlayfs/readdir.c | 11 ++-- fs/overlayfs/super.c | 125 ++++++++++++++++++++++----------------- fs/overlayfs/util.c | 18 ++---- 8 files changed, 134 insertions(+), 117 deletions(-) -- 2.17.1
