New upstream version 2016.11

src/rofiles-fuse/README.md

@@ -1,48 +0,0 @@
-rofiles-fuse
-============
-
-Create a mountpoint that represents an underlying directory hierarchy,
-but where non-directory inodes cannot have content or xattrs changed.
-Files can still be unlinked, and new ones created.
-
-This filesystem is designed for OSTree and other systems that create
-"hardlink farms", i.e. filesystem trees deduplicated via hardlinks.
-
-Normally with hard links, if you change one, you change them all.
-
-There are two approaches to dealing with that:
- - Copy on write: implemented by BTRFS, overlayfs, and http://linux-vserver.org/util-vserver:Vhashify
- - Make them read-only: what this FUSE mount does
-
-Usage
-=====
-
-Let's say that you have immutable data in `/srv/backups/20150410`, and
-you want to update it with a new version, storing the result in
-`/srv/backups/20150411`.  Further assume that all software operating
-on the directory does the "create tempfile and `rename()`" dance
-rather than in-place edits.
-
-    $ mkdir -p /srv/backups/mnt   # Ensure we have a mount point
-    $ cp -al /srv/backups/20150410 /srv/backups/20150411
-    $ rofiles-fuse /srv/backups/20150411 /srv/backups/mnt
-
-Now we have a "rofiles" mount at `/srv/backups/mnt`.  If we try this:
-
-    $ echo new doc content > /srv/backups/mnt/document
-    bash: /srv/backups/mnt/document: Read-only file system
-
-It failed because the `>` redirection operator will try to truncate
-the existing file.  If instead we create `document.tmp` and then
-rename it atomically over the old one, it will work:
-
-    $ echo new doc content > /srv/backups/mnt/document.tmp
-    $ mv /srv/backups/mnt/document.tmp /srv/backups/mnt/document
-
-Let's unmount:
-
-    $ fusermount -u /srv/backups/mnt
-
-Now we have two directories `/srv/backups/20150410`
-`/srv/backups/20150411` which share all file storage except for the
-new document.