Miklos, This series implements NFS export support [3] and is based on two prep patch sets [1][2] posted earlier to overlayfs list. NFS export is enabled for overlayfs mount with the 'verify_dir' and 'index=all' mount options. The current implementation will copy up and index directories when directory file handles are encoded. Those extra copy ups could be avoided in the future. The current implementation does NOT support encoding connectable non-dir file handles for all overlay path types, so overlayfs should not be exported with the 'subtree_check' option. I hope this is not a show stopper for merging NFS export support? You'll notice that the series start by implementing naiive support for pure upper files export and later on, replaces the implementation of some of the operations. This may seem strange, but I found it convenient to progress slowly between testable mile stones and I find the series easier to review this way. Let me know if you want me to change the way that this series is organized to get rid of code that is later removed. To unit test overlayfs file handles, I enhanced xfstest open_by_handle test utility to encode/decode directories and check several other cases that were not covered by the original xfstest test. On my xfstests NFS export branch [4], there are two generic tests and one overlayfs specific test on the 'exportfs' group. I also ran the NFSTest nfstest_posix group on an exported overlayfs mount, but that test only creates pure upper files in overlay upper dir, so it is not much of a stress to the implementation. Amir. [1] https://github.com/amir73il/linux/commits/ovl-verify-dir [2] https://github.com/amir73il/linux/commits/ovl-index-all [3] https://github.com/amir73il/linux/commits/ovl-nfs-export [4] https://github.com/amir73il/xfstests/commits/ovl-nfs-export Amir Goldstein (14): ovl: hash all overlay inodes for NFS export ovl: grab i_count reference of lower inode ovl: use d_splice_alias() in place of d_add() in lookup ovl: copy up of disconnected dentries ovl: encode/decode pure-upper non-connectable file handles ovl: encode pure-upper connectable file handles ovl: decode pure-upper connectable file handles ovl: encode/decode struct ovl_fh format file handles ovl: encode non-pure-upper non-connectable file handles ovl: obtain a non-pure-upper disconnected dentry ovl: decode non-pure-upper non-connectable file handles ovl: reconnect non-pure-upper dir file handles ovl: wire up NFS export support ovl: document NFS export Documentation/filesystems/overlayfs.txt | 61 +++++ fs/overlayfs/Makefile | 3 +- fs/overlayfs/copy_up.c | 74 ++++-- fs/overlayfs/export.c | 433 ++++++++++++++++++++++++++++++++ fs/overlayfs/inode.c | 23 +- fs/overlayfs/namei.c | 96 ++++--- fs/overlayfs/overlayfs.h | 32 ++- fs/overlayfs/super.c | 25 ++ fs/overlayfs/util.c | 13 +- 9 files changed, 678 insertions(+), 82 deletions(-) create mode 100644 fs/overlayfs/export.c -- 2.7.4
