ceph: support hidden vxattrs

Add ability to flag virtual xattrs as hidden, such that you can
getxattr them but they do not appear in listxattr.

Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Sam Lang <sam.lang@inktank.com>

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index c2048b1..43063d0 100644 (file)
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -29,7 +29,7 @@ struct ceph_vxattr {
        size_t name_size;       /* strlen(name) + 1 (for '\0') */
        size_t (*getxattr_cb)(struct ceph_inode_info *ci, char *val,
                              size_t size);
-       bool readonly;
+       bool readonly, hidden;
 };
 
 /* directories */
@@ -85,13 +85,14 @@ static size_t ceph_vxattrcb_dir_rctime(struct ceph_inode_info *ci, char *val,
 
 #define CEPH_XATTR_NAME(_type, _name)  XATTR_CEPH_PREFIX #_type "." #_name
 
-#define XATTR_NAME_CEPH(_type, _name) \
-               { \
-                       .name = CEPH_XATTR_NAME(_type, _name), \
-                       .name_size = sizeof (CEPH_XATTR_NAME(_type, _name)), \
-                       .getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name, \
-                       .readonly = true, \
-               }
+#define XATTR_NAME_CEPH(_type, _name)                                  \
+       {                                                               \
+               .name = CEPH_XATTR_NAME(_type, _name),                  \
+               .name_size = sizeof (CEPH_XATTR_NAME(_type, _name)), \
+               .getxattr_cb = ceph_vxattrcb_ ## _type ## _ ## _name, \
+               .readonly = true,                               \
+               .hidden = false,                                \
+       }
 
 static struct ceph_vxattr ceph_dir_vxattrs[] = {
        XATTR_NAME_CEPH(dir, entries),
@@ -157,7 +158,8 @@ static size_t __init vxattrs_name_size(struct ceph_vxattr *vxattrs)
        size_t size = 0;
 
        for (vxattr = vxattrs; vxattr->name; vxattr++)
-               size += vxattr->name_size;
+               if (!vxattr->hidden)
+                       size += vxattr->name_size;
 
        return size;
 }