Here is the current patch set for writable overlays (union mounts). It needs lots of review! Especially the bits where we do nasty things with readdir(). Writable overlays let you mount one read-write file system transparently over another read-only file system. This is useful for things like LiveCDs. Detailed documentation and HOWTO here: http://valerieaurora.org/union/ The git version is in branch "overlay" of: http://git.kernel.org/?p=linux/kernel/git/val/linux-2.6.git;a=summary Call for maintainer: Neither Jan nor I can give this patch set the long term love that it needs. If you are interested in becoming the maintainer for union mounts at some point in the future, please drop me an email. -VAL Felix Fietkau (2): whiteout: jffs2 whiteout support fallthru: jffs2 fallthru support Jan Blunck (25): VFS: BUG() if somebody tries to rehash an already hashed dentry VFS: propagate mnt_flags into do_loopback VFS: Make lookup_hash() return a struct path VFS: Remove unnecessary micro-optimization in cached_lookup() VFS: Make real_lookup() return a struct path VFS: Introduce dput() variant that maintains a kill-list Don't replace nameidata path when following links whiteout: 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 union-mount: Allow removal of a directory whiteout: tmpfs whiteout support whiteout: Split of ext2_append_link() from ext2_add_link() whiteout: ext2 whiteout support whiteout: Add path_whiteout() helper union-mount: Introduce MNT_UNION and MS_UNION flags union-mount: Introduce union_mount structure union-mount: Drive the union cache via dcache union-mount: Some checks during namespace changes union-mount: Changes to the namespace handling union-mount: Make lookup work for union-mounted file systems union-mount: stop lookup when directory has S_OPAQUE flag set union-mount: stop lookup when finding a whiteout union-mount: call do_whiteout() on unlink and rmdir union-mount: Add support for rename by __union_copyup() Valerie Aurora (14): VFS: Add read-only users count to superblock union-mount: Documentation union-mount: in-kernel file copy between union mounted filesystems union-mount: Always create topmost directory on open fallthru: Basic fallthru definitions fallthru: Support for fallthru entries in union mount lookup fallthru: ext2 fallthru support fallthru: tmpfs fallthru support union-mount: Copy up directory entries on first readdir() union-mount: Increment read-only users count for read-only layer union-mount: Check read-only/read-write status of layers union-mount: Make pivot_root work with union mounts union-mount: Ignore read-only file system in permission checks union-mount: Make truncate work in all its glorious UNIX variations Documentation/filesystems/union-mounts.txt | 708 ++++++++++++++ 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 | 143 +++- fs/ext2/dir.c | 248 +++++- fs/ext2/ext2.h | 4 + fs/ext2/inode.c | 11 +- fs/ext2/namei.c | 85 ++- fs/ext2/super.c | 7 + fs/jffs2/dir.c | 108 ++- fs/jffs2/fs.c | 4 + fs/jffs2/super.c | 2 +- fs/libfs.c | 21 +- fs/namei.c | 1424 +++++++++++++++++++++++++--- fs/namespace.c | 120 +++- fs/nfsctl.c | 6 +- fs/nfsd/nfs3xdr.c | 5 + fs/nfsd/nfs4xdr.c | 2 +- fs/nfsd/nfsxdr.c | 4 + fs/open.c | 130 +-- fs/readdir.c | 26 + fs/super.c | 14 + fs/union.c | 978 +++++++++++++++++++ include/linux/dcache.h | 29 + include/linux/ext2_fs.h | 5 + include/linux/fs.h | 15 +- include/linux/jffs2.h | 8 + include/linux/mount.h | 4 + include/linux/namei.h | 6 + include/linux/union.h | 84 ++ mm/shmem.c | 195 ++++- 35 files changed, 4172 insertions(+), 265 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
