This patch series implements union mounts for every system call except: - xattr-related calls - fchmod()/fchown()/futimensat() on an fd The copyup portion is a proof of concept based around union_path_nd(), which looks up both the target <mnt,dentry> pair and its parent's. If the parent is on a union mount, and the target is on a lower layer, we copy up the target. This patch set is very raw and could use even the most superficial review. Just take a look at Erez's review from December to see how low-hanging the fruit is on this one. -VAL Felix Fietkau (2): whiteout: jffs2 whiteout support fallthru: jffs2 fallthru support Jan Blunck (13): VFS: Make lookup_hash() return a struct path XXX autofs4: Save autofs trigger's vfsmount in super block info whiteout/NFSD: Don't return information about whiteouts to userspace whiteout: Add vfs_whiteout() and whiteout inode operation whiteout: Set S_OPAQUE inode flag when creating directories whiteout: Allow removal of a directory with whiteouts whiteout: tmpfs whiteout support whiteout: Split of ext2_append_link() from ext2_add_link() whiteout: ext2 whiteout support union-mount: Introduce MNT_UNION and MS_UNION flags union-mount: Introduce union_mount structure and basic operations union-mount: Drive the union cache via dcache union-mount: Call do_whiteout() on unlink and rmdir in unions Valerie Aurora (20): VFS: Add read-only users count to superblock fallthru: Basic fallthru definitions fallthru: ext2 fallthru support fallthru: tmpfs fallthru support union-mount: Writable overlays/union mounts documentation union-mount: Implement union lookup union-mount: Support for mounting union mount file systems union-mount: Copy up directory entries on first readdir() VFS: Split inode_permission() and create path_permission() VFS: Create user_path_nd() to lookup both parent and target union-mount: In-kernel copyup routines union-mount: Implement union-aware access()/faccessat() union-mount: Implement union-aware link() union-mount: Implement union-aware rename() union-mount: Implement union-aware writable open() union-mount: Implement union-aware chown() union-mount: Implement union-aware truncate() union-mount: Implement union-aware chmod()/fchmodat() union-mount: Implement union-aware lchown() union-mount: Implement union-aware utimensat() Documentation/filesystems/union-mounts.txt | 708 ++++++++++++++++++++++ Documentation/filesystems/vfs.txt | 16 +- fs/Kconfig | 13 + fs/Makefile | 1 + fs/autofs4/autofs_i.h | 1 + fs/autofs4/init.c | 11 +- fs/autofs4/root.c | 6 + fs/compat.c | 9 + fs/dcache.c | 35 +- fs/ext2/dir.c | 248 +++++++- fs/ext2/ext2.h | 4 + fs/ext2/inode.c | 11 +- fs/ext2/namei.c | 89 +++- fs/ext2/super.c | 6 + fs/jffs2/dir.c | 104 ++++- fs/jffs2/fs.c | 4 + fs/jffs2/super.c | 2 +- fs/libfs.c | 21 +- fs/namei.c | 793 ++++++++++++++++++++++--- fs/namespace.c | 146 +++++- fs/nfsd/nfs3xdr.c | 5 + fs/nfsd/nfs4xdr.c | 5 + fs/nfsd/nfsxdr.c | 4 + fs/open.c | 116 +++- fs/readdir.c | 18 + fs/super.c | 23 + fs/union.c | 881 ++++++++++++++++++++++++++++ fs/utimes.c | 13 +- include/linux/dcache.h | 40 ++ include/linux/ext2_fs.h | 5 + include/linux/fs.h | 16 + include/linux/jffs2.h | 8 + include/linux/mount.h | 7 +- include/linux/namei.h | 2 + include/linux/union.h | 77 +++ mm/shmem.c | 195 ++++++- 36 files changed, 3483 insertions(+), 160 deletions(-) create mode 100644 Documentation/filesystems/union-mounts.txt create mode 100644 fs/union.c create mode 100644 include/linux/union.h -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
