From: Alin Dobre <alinmd@gmail.com> Following Chris' idea and thread started on the linux mailing list ([1]), I have started to implement such a filesystem starting from the current Wrapfs code, which should do a simple mapping from UID 1000 on the lower filesystem to UID 1001 on the upper filesystem. My kernel tree is based on the 3.10-rc7 kernel.org tree (this was the master tip at the time I mirrored it and started development) and has the Wrapfs commits [2] on top of it. Patches should apply on latest kernel versions without any issues. Currently only UIDs are mapped, GIDs will follow somewhere at the end of the implementation, since it will just mean copying most of the UID related code. In general, the implementation manipulates the i_uid at inode level and fsuid at file level operations. Current code is still under development, but I wanted to start and gather feedback, so I would be more than happy to hear your thoughts around this. Thanks! Alin. [1] http://www.gossamer-threads.com/lists/linux/kernel/1726499?do=post_view_thre... [2] http://git.fsl.cs.sunysb.edu/?p=wrapfs-latest.git;a=summary Alin Dobre (3): Minimum wrapfs rename Mapping for multiple operations Mapping read/write with fsuid fs/Kconfig | 2 +- fs/Makefile | 2 +- fs/idmapfs/Kconfig | 8 + fs/idmapfs/Makefile | 7 + fs/idmapfs/dentry.c | 49 ++++++ fs/idmapfs/file.c | 331 ++++++++++++++++++++++++++++++++++++ fs/idmapfs/inode.c | 469 ++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/idmapfs/lookup.c | 355 +++++++++++++++++++++++++++++++++++++++ fs/idmapfs/main.c | 174 +++++++++++++++++++ fs/idmapfs/mmap.c | 53 ++++++ fs/idmapfs/super.c | 168 +++++++++++++++++++ fs/idmapfs/wrapfs.h | 214 ++++++++++++++++++++++++ fs/wrapfs/Kconfig | 8 - fs/wrapfs/Makefile | 7 - fs/wrapfs/dentry.c | 49 ------ fs/wrapfs/file.c | 295 --------------------------------- fs/wrapfs/inode.c | 463 --------------------------------------------------- fs/wrapfs/lookup.c | 332 ------------------------------------- fs/wrapfs/main.c | 174 ------------------- fs/wrapfs/mmap.c | 53 ------ fs/wrapfs/super.c | 168 ------------------- fs/wrapfs/wrapfs.h | 205 ----------------------- 22 files changed, 1830 insertions(+), 1756 deletions(-) create mode 100644 fs/idmapfs/Kconfig create mode 100644 fs/idmapfs/Makefile create mode 100644 fs/idmapfs/dentry.c create mode 100644 fs/idmapfs/file.c create mode 100644 fs/idmapfs/inode.c create mode 100644 fs/idmapfs/lookup.c create mode 100644 fs/idmapfs/main.c create mode 100644 fs/idmapfs/mmap.c create mode 100644 fs/idmapfs/super.c create mode 100644 fs/idmapfs/wrapfs.h delete mode 100644 fs/wrapfs/Kconfig delete mode 100644 fs/wrapfs/Makefile delete mode 100644 fs/wrapfs/dentry.c delete mode 100644 fs/wrapfs/file.c delete mode 100644 fs/wrapfs/inode.c delete mode 100644 fs/wrapfs/lookup.c delete mode 100644 fs/wrapfs/main.c delete mode 100644 fs/wrapfs/mmap.c delete mode 100644 fs/wrapfs/super.c delete mode 100644 fs/wrapfs/wrapfs.h -- 1.8.3.2