ceph: add ceph.caps vxattr

Add a new vxattr that allows userspace to list the caps for a specific
directory or file.

[ jlayton: change format delimiter to '/' ]

Signed-off-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index e89750a..cd8c7aa 100644 (file)
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -321,6 +321,19 @@ static ssize_t ceph_vxattrcb_client_id(struct ceph_inode_info *ci,
                              ceph_client_gid(fsc->client));
 }
 
+static ssize_t ceph_vxattrcb_caps(struct ceph_inode_info *ci, char *val,
+                                       size_t size)
+{
+       int issued;
+
+       spin_lock(&ci->i_ceph_lock);
+       issued = __ceph_caps_issued(ci, NULL);
+       spin_unlock(&ci->i_ceph_lock);
+
+       return ceph_fmt_xattr(val, size, "%s/0x%x",
+                             ceph_cap_string(issued), issued);
+}
+
 #define CEPH_XATTR_NAME(_type, _name)  XATTR_CEPH_PREFIX #_type "." #_name
 #define CEPH_XATTR_NAME2(_type, _name, _name2) \
        XATTR_CEPH_PREFIX #_type "." #_name "." #_name2
@@ -396,6 +409,13 @@ static struct ceph_vxattr ceph_dir_vxattrs[] = {
                .exists_cb = ceph_vxattrcb_snap_btime_exists,
                .flags = VXATTR_FLAG_READONLY,
        },
+       {
+               .name = "ceph.caps",
+               .name_size = sizeof("ceph.caps"),
+               .getxattr_cb = ceph_vxattrcb_caps,
+               .exists_cb = NULL,
+               .flags = VXATTR_FLAG_HIDDEN,
+       },
        { .name = NULL, 0 }     /* Required table terminator */
 };
 
@@ -421,6 +441,13 @@ static struct ceph_vxattr ceph_file_vxattrs[] = {
                .exists_cb = ceph_vxattrcb_snap_btime_exists,
                .flags = VXATTR_FLAG_READONLY,
        },
+       {
+               .name = "ceph.caps",
+               .name_size = sizeof("ceph.caps"),
+               .getxattr_cb = ceph_vxattrcb_caps,
+               .exists_cb = NULL,
+               .flags = VXATTR_FLAG_HIDDEN,
+       },
        { .name = NULL, 0 }     /* Required table terminator */
 };