[v2,0/6] Overlayfs stacked f_op fixes

Message

Amir Goldstein Aug. 26, 2018, 4:25 p.m. UTC

Miklos,

Following are fixes to some stacked f_op regressions, also
availabel on my ovl-fixes branch [1].

Patches 2-3 fix fiemap() and swapon() regressions detected
by xfstests.

Per your suggestion, f_mapping now points to the overlay
inode mapping and as a result, swapfile support is disabled on
an overlayfs file.
Also disabled is FIBMAP on an overlayfs file - not a big loss.

Patch 1 adds the vfs helper file_real() to access overlayfs
real file and patches 4-6 use this helper to untangle from
the f_mapping change.

Please note that patch 4 fixes a problem that was verified
with an LTP test [2], but patches 5-6 fix theoretical problems
that I have not yet demonstrated with a test.

Thanks,
Amir.

[1] https://github.com/amir73il/linux/commits/ovl-fixes
[2] https://github.com/amir73il/ltp/commits/overlayfs-devel

Amir Goldstein (6):
  vfs: add helper to get "real" overlayfs file
  ovl: respect FIEMAP_FLAG_SYNC flag
  ovl: fix GPF in swapfile_activate of file from overlayfs over xfs
  vfs: fix readahead syscall on an overlayfs file
  vfs: fix fadvise64 syscall on an overlayfs file
  vfs: fix sync_file_range syscall on an overlayfs file

 fs/overlayfs/file.c  |  4 +---
 fs/overlayfs/inode.c | 10 ++++++++++
 fs/sync.c            | 14 ++++++++++----
 include/linux/fs.h   | 27 +++++++++++++++++++++++++++
 mm/fadvise.c         | 34 ++++++++++++++++++++--------------
 mm/readahead.c       |  9 +++++++--
 6 files changed, 75 insertions(+), 23 deletions(-)