posix: add ACL translation for the GF_POSIX_ACL_*_KEY xattr

Adding support for two virtual extended attributes that are used for
converting a binary POSIX ACL to a POSIX.1e long ACL text format. This
makes it possible to transfer the ACL over the network to a different OS
which can convert the POSIX.1e text format to its native structures.

The following xattrs are sent over RPC in SETXATTR/GETXATTR procedures,
and contain the POSIX.1e long ACL text format:

- glusterfs.posix.acl: maps to ACL_TYPE_ACCESS
- glusterfs.posix.default_acl: maps to ACL_TYPE_DEFAULT

acl_from_text() (from libacl) converts the text format into an acl_t
structure. This structure is then used by acl_set_file() to set the ACL
in the filesystem.

libacl-devel is needed for linking against libacl, so it has been added
to the BuildRequires in the .spec.

NetBSD does not support POSIX ACLs. Trying to get/set POSIX ACLs on a
storage server running NetBSD, an error will be returned with errno set
to ENOTSUP. Faking support, but not enforcing ACLs seems wrong to me.

URL: http://www.gluster.org/community/documentation/index.php/Features/Improved_POSIX_ACLs
BUG: 1185654
Change-Id: Ic5eb73d69190d3492df2f711d0436775eeea7de3
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/9627
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: soumya k <skoduri@redhat.com>
Reviewed-by: Raghavendra Bhat <raghavendra@redhat.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index ccd441a2d62..47afed7fdad 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -3660,6 +3660,32 @@ posix_getxattr (call_frame_t *frame, xlator_t *this,
                 goto out;
         }
 
+        if (loc->inode && name && GF_POSIX_ACL_REQUEST (name)) {
+                ret = posix_pacl_get (real_path, name, &value);
+                if (ret || !value) {
+                        gf_log (this->name, GF_LOG_WARNING,
+                                "could not get acl (%s) for %s: %s", name,
+                                real_path, strerror (errno));
+                        op_ret = -1;
+                        op_errno = errno;
+                        goto out;
+                }
+
+                ret = dict_set_dynstr (dict, (char *)name, value);
+                if (ret < 0) {
+                        GF_FREE (value);
+                        gf_log (this->name, GF_LOG_WARNING,
+                                "could not set acl (%s) for %s in dictionary: "
+                                "(%s)", name, real_path, strerror (errno));
+                        op_ret = -1;
+                        op_errno = errno;
+                        goto out;
+                }
+
+                size = ret;
+                goto done;
+        }
+
 	if (loc->inode && name &&
 	    (strncmp (name, GF_XATTR_GET_REAL_FILENAME_KEY,
 		      strlen (GF_XATTR_GET_REAL_FILENAME_KEY)) == 0)) {