Commit Graph

13 Commits

Author SHA1 Message Date
Amir Goldstein 9412812ef5 ovl: document copying layers restrictions with inodes index
The inodes index feature introduces a behavior change - on mount,
upper root origin file handle is verified to match the lower root dir.
This implies that copied layers cannot be mounted with the inodes index
feature enabled, without explicitly removing the upper dir origin xattr
and the index dir.

The inodes index feature is required to support:
- Prevent breaking hardlinks on copy up
- NFS export support (upcoming)
- Overlayfs snapshots (POC)

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04 22:03:19 +02:00
Amir Goldstein 65f2673832 ovl: update documentation w.r.t. constant inode numbers
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-05-05 11:38:59 +02:00
Amir Goldstein c3c8699664 ovl: fix reStructuredText syntax errors in documentation
- Fix broken long line block quote
 - Fix missing newline before bullets list
 - Use correct numbered list syntax

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-12-16 11:02:58 +01:00
Miklos Szeredi a6c6065511 ovl: redirect on rename-dir
Current code returns EXDEV when a directory would need to be copied up to
move.  We could copy up the directory tree in this case, but there's
another, simpler solution: point to old lower directory from moved upper
directory.

This is achieved with a "trusted.overlay.redirect" xattr storing the path
relative to the root of the overlay.  After such attribute has been set,
the directory can be moved without further actions required.

This is a backward incompatible feature, old kernels won't be able to
correctly mount an overlay containing redirected directories.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-12-16 11:02:56 +01:00
Miklos Szeredi 2d8f2908e6 ovl: update doc
The quirk for file locks and leases no longer applies.

Add missing info about renaming directory residing on lower layer.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-12-16 11:02:54 +01:00
Miklos Szeredi 026e5e0cc1 ovl: update doc
Some of the documented quirks no longer apply.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-01 11:12:00 +02:00
Miklos Szeredi 942fd803e6 ovl: update documentation
Two "fixme" items are actually fixed now.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-05-27 08:55:26 +02:00
NeilBrown a907c90765 Remove email address from Documentation/filesystems/overlayfs.txt
I'm getting a surprising large number of questions about overlayfs sent
to me personally, rather than to a relevant mailing list.

So remove my email address from the documentation, and add a note
about looking in the MAINTAINERS file.

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-11-11 10:04:53 -07:00
Miklos Szeredi 6d900f5a33 ovl: document lower layer ordering
Reported-by: Fabian Sturm <fabian.sturm@aduu.de> 
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2015-01-08 15:09:15 +01:00
Miklos Szeredi 2b7a8f36f0 ovl: add testsuite to docs
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13 00:59:53 +01:00
Miklos Szeredi a78d9f0d5d ovl: support multiple lower layers
Allow "lowerdir=" option to contain multiple lower directories separated by
a colon (e.g. "lowerdir=/bin:/usr/bin").  Colon characters in filenames can
be escaped with a backslash.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13 00:59:52 +01:00
Miklos Szeredi ef94b1864d ovl: rename filesystem type to "overlay"
Some distributions carry an "old" format of overlayfs while mainline has a
"new" format.

The distros will possibly want to keep the old overlayfs alongside the new
for compatibility reasons.

To make it possible to differentiate the two versions change the name of
the new one from "overlayfs" to "overlay".

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reported-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: Andy Whitcroft <apw@canonical.com>
2014-11-20 16:39:59 +01:00
Neil Brown 7c37fbda85 overlay: overlay filesystem documentation
Document the overlay filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-10-24 00:14:39 +02:00