[Buildroot] [git commit] fs/tar: add support for xattrs (thus capabilties)

[Buildroot] [git commit] fs/tar: add support for xattrs (thus capabilties)

[Peter Korsgaard]

commit: https://git.buildroot.net/buildroot/commit/?id=6d688e2132f9feb63e325c2456d23edfc53f79a8
branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/master

By default, tar will not include any extended attribute (xattr) when
creating archives, and thus will not store capabilties either (as they
are stored in the xattr 'security.capability').

Using option --xattrs is enough to create a tarball with all the xattrs
attached to a file. However, extracting all xattrs from a tarball
requires that --xattrs-include='*' be used. This is not symetric (but on
purpose, as per the documentation), and so is confusing to some.

So, we use --xattrs-include='*' to create the archive, so as to be
explicit that we want all xattrs to be stored.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Ricardo Martincoski <ricardo.martincoski@gmail.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
Cc: Arnout Vandecappelle <arnout@mind.be>
Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
---
 fs/tar/tar.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/tar/tar.mk b/fs/tar/tar.mk
index 68149e9eb7..4c6327ace8 100644
--- a/fs/tar/tar.mk
+++ b/fs/tar/tar.mk
@@ -10,7 +10,7 @@ ROOTFS_TAR_DEPENDENCIES = $(BR2_TAR_HOST_DEPENDENCY)
 
 define ROOTFS_TAR_CMD
 	(cd $(TARGET_DIR); find -print0 | LC_ALL=C sort -z | \
-		tar $(TAR_OPTS) -cf $@ --null --no-recursion -T - --numeric-owner)
+		tar $(TAR_OPTS) -cf $@ --null --xattrs-include='*' --no-recursion -T - --numeric-owner)
 endef
 
 $(eval $(rootfs))

[Buildroot] [git commit] fs/tar: add support for xattrs (thus capabilties)

[Peter Korsgaard]

>>>>> "Peter" == Peter Korsgaard <peter@korsgaard.com> writes:

 > commit: https://git.buildroot.net/buildroot/commit/?id=6d688e2132f9feb63e325c2456d23edfc53f79a8
 > branch: https://git.buildroot.net/buildroot/commit/?id=refs/heads/master

 > By default, tar will not include any extended attribute (xattr) when
 > creating archives, and thus will not store capabilties either (as they
 > are stored in the xattr 'security.capability').

 > Using option --xattrs is enough to create a tarball with all the xattrs
 > attached to a file. However, extracting all xattrs from a tarball
 > requires that --xattrs-include='*' be used. This is not symetric (but on
 > purpose, as per the documentation), and so is confusing to some.

 > So, we use --xattrs-include='*' to create the archive, so as to be
 > explicit that we want all xattrs to be stored.

 > Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
 > Cc: Ricardo Martincoski <ricardo.martincoski@gmail.com>
 > Cc: Peter Korsgaard <peter@korsgaard.com>
 > Cc: Arnout Vandecappelle <arnout@mind.be>
 > Reviewed-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
 > Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

Committed to 2018.02.x and 2018.08.x, thanks.

-- 
Bye, Peter Korsgaard