[PATCH RFC 0/2] ceph: size handling for the fscrypt

[xiubli@redhat.com]

From: Xiubo Li <xiubli@redhat.com>

This patch series is based Jeff's ceph-fscrypt-size-experimental
branch in https://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux.git.

This is just a draft patch and need to rebase or recode after Jeff
finished his huge patch set.

Post the patch out for advices and ideas. Thanks.

====

This approach will not do the rmw immediately after the file is
truncated. If the truncate size is aligned to the BLOCK SIZE, so
there no need to do the rmw and only in unaligned case will the
rmw is needed.

And the 'fscrypt_file' field will be cleared after the rmw is done.
If the 'fscrypt_file' is none zero that means after the kclient
reading that block to local buffer or pagecache it needs to do the
zeroing of that block in range of [fscrypt_file, round_up(fscrypt_file,
BLOCK SIZE)).

Once any kclient has dirty that block and write it back to ceph, the
'fscrypt_file' field will be cleared and set to 0. More detail please
see the commit comments in the second patch.

There also need on small work in Jeff's MDS PR in cap flushing code
to clear the 'fscrypt_file'.


Xiubo Li (2):
  Revert "ceph: make client zero partial trailing block on truncate"
  ceph: truncate the file contents when needed when file scrypted

 fs/ceph/addr.c  | 19 ++++++++++++++-
 fs/ceph/caps.c  | 24 ++++++++++++++++++
 fs/ceph/file.c  | 65 ++++++++++++++++++++++++++++++++++++++++++++++---
 fs/ceph/inode.c | 48 +++++++++++++++++++-----------------
 fs/ceph/super.h | 13 +++++++---
 5 files changed, 138 insertions(+), 31 deletions(-)

-- 
2.27.0