Miklos, This v2 combines the prep patch set [1] and lazy lookup patch set [2]. This work is motivated by Alexander's composefs use case. Alexander has been developing and testing his fsverity patches over my lazy-lowerdata-lookup branch [3]. Alexander has also written tests for lazy lowerdata lookup [4]. Note that patch #1 is a Fixes patch for stable. Gao commented that the fix may not be complete, but I think it is better than no fix at all. Regarding lazy lookup in d_real(), I am not sure if the best effort lookup is the best solution, but in any case, none of this code kicks in without explicit opt-in to data-only layers, so the risk of breaking existing setups is quite low. Thanks, Amir. Changes since v1: - Include the prep patch set - Split remove lowerdata from add lowerdata_redirect patch - Remove embedded ovl_entry stack optimization - Add lazy lookup and comment in d_real_inode() - Improve documentation of :: data-only layers syntax - Added RVBs [1] https://lore.kernel.org/linux-unionfs/20230408164302.1392694-1-amir73il@xxxxxxxxx/ [2] https://lore.kernel.org/linux-unionfs/20230412135412.1684197-1-amir73il@xxxxxxxxx/ [3] https://github.com/amir73il/linux/commits/ovl-lazy-lowerdata [4] https://github.com/amir73il/xfstests/commits/ovl-lazy-lowerdata Amir Goldstein (13): ovl: update of dentry revalidate flags after copy up ovl: use OVL_E() and OVL_E_FLAGS() accessors ovl: use ovl_numlower() and ovl_lowerstack() accessors ovl: factor out ovl_free_entry() and ovl_stack_*() helpers ovl: move ovl_entry into ovl_inode ovl: deduplicate lowerpath and lowerstack[] ovl: deduplicate lowerdata and lowerstack[] ovl: remove unneeded goto instructions ovl: introduce data-only lower layers ovl: implement lookup in data-only layers ovl: prepare to store lowerdata redirect for lazy lowerdata lookup ovl: prepare for lazy lookup of lowerdata inode ovl: implement lazy lookup of lowerdata in data-only layers Documentation/filesystems/overlayfs.rst | 36 +++++ fs/overlayfs/copy_up.c | 11 ++ fs/overlayfs/dir.c | 3 +- fs/overlayfs/export.c | 41 +++--- fs/overlayfs/file.c | 21 ++- fs/overlayfs/inode.c | 38 +++-- fs/overlayfs/namei.c | 185 +++++++++++++++++++----- fs/overlayfs/overlayfs.h | 20 ++- fs/overlayfs/ovl_entry.h | 73 ++++++++-- fs/overlayfs/super.c | 132 ++++++++++------- fs/overlayfs/util.c | 165 ++++++++++++++++----- 11 files changed, 534 insertions(+), 191 deletions(-) -- 2.34.1
