Posix ACL Support

This change adds support for Posix ACLs by storing them as an xattr
which is common practice for many Linux file systems.  Since the
Posix ACL is stored as an xattr it will not overwrite any existing
ZFS/NFSv4 ACLs which may have been set.  The Posix ACL will also
be non-functional on other platforms although it may be visible
as an xattr if that platform understands SA based xattrs.

By default Posix ACLs are disabled but they may be enabled with
the new 'aclmode=noacl|posixacl' property.  Set the property to
'posixacl' to enable them.  If ZFS/NFSv4 ACL support is ever added
an appropriate acltype will be added.

This change passes the POSIX Test Suite cleanly with the exception
of xacl/00.t test 45 which is incorrect for Linux (Ext4 fails too).

  http://www.tuxera.com/community/posix-test-suite/

Signed-off-by: Massimo Maggi <[email protected]>
Signed-off-by: Richard Yao <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #170

1 files changed, 38 insertions, 2 deletions

diff --git a/module/zfs/zfs_vfsops.c b/module/zfs/zfs_vfsops.c
index eeac0391c..3af174479 100644
--- a/module/zfs/zfs_vfsops.c
+++ b/module/zfs/zfs_vfsops.c
@@ -155,6 +155,25 @@ xattr_changed_cb(void *arg, uint64_t newval)
 }
 
 static void
+acltype_changed_cb(void *arg, uint64_t newval)
+{
+	zfs_sb_t *zsb = arg;
+
+	switch (newval) {
+	case ZFS_ACLTYPE_OFF:
+		zsb->z_acl_type = ZFS_ACLTYPE_OFF;
+		zsb->z_sb->s_flags &= ~MS_POSIXACL;
+		break;
+	case ZFS_ACLTYPE_POSIXACL:
+		zsb->z_acl_type = ZFS_ACLTYPE_POSIXACL;
+		zsb->z_sb->s_flags |= MS_POSIXACL;
+		break;
+	default:
+		break;
+	}
+}
+
+static void
 blksz_changed_cb(void *arg, uint64_t newval)
 {
 	zfs_sb_t *zsb = arg;
@@ -266,8 +285,9 @@ zfs_register_callbacks(zfs_sb_t *zsb)
 	error = error ? error : dsl_prop_register(ds,
 	    zfs_prop_to_name(ZFS_PROP_SNAPDIR), snapdir_changed_cb, zsb);
 	error = error ? error : dsl_prop_register(ds,
-	    zfs_prop_to_name(ZFS_PROP_ACLINHERIT), acl_inherit_changed_cb,
-	    zsb);
+	    zfs_prop_to_name(ZFS_PROP_ACLTYPE), acltype_changed_cb, zsb);
+	error = error ? error : dsl_prop_register(ds,
+	    zfs_prop_to_name(ZFS_PROP_ACLINHERIT), acl_inherit_changed_cb, zsb);
 	error = error ? error : dsl_prop_register(ds,
 	    zfs_prop_to_name(ZFS_PROP_VSCAN), vscan_changed_cb, zsb);
 	error = error ? error : dsl_prop_register(ds,
@@ -303,6 +323,8 @@ unregister:
 	    exec_changed_cb, zsb);
 	(void) dsl_prop_unregister(ds, zfs_prop_to_name(ZFS_PROP_SNAPDIR),
 	    snapdir_changed_cb, zsb);
+	(void) dsl_prop_unregister(ds, zfs_prop_to_name(ZFS_PROP_ACLTYPE),
+	    acltype_changed_cb, zsb);
 	(void) dsl_prop_unregister(ds, zfs_prop_to_name(ZFS_PROP_ACLINHERIT),
 	    acl_inherit_changed_cb, zsb);
 	(void) dsl_prop_unregister(ds, zfs_prop_to_name(ZFS_PROP_VSCAN),
@@ -663,6 +685,10 @@ zfs_sb_create(const char *osname, zfs_sb_t **zsbp)
 		goto out;
 	zsb->z_case = (uint_t)zval;
 
+	if ((error = zfs_get_zplprop(os, ZFS_PROP_ACLTYPE, &zval)) != 0)
+		goto out;
+	zsb->z_acl_type = (uint_t)zval;
+
 	/*
 	 * Fold case on file systems that are always or sometimes case
 	 * insensitive.
@@ -904,6 +930,9 @@ zfs_unregister_callbacks(zfs_sb_t *zsb)
 		VERIFY(dsl_prop_unregister(ds, "snapdir", snapdir_changed_cb,
 		    zsb) == 0);
 
+		VERIFY(dsl_prop_unregister(ds, "acltype", acltype_changed_cb,
+		    zsb) == 0);
+
 		VERIFY(dsl_prop_unregister(ds, "aclinherit",
 		    acl_inherit_changed_cb, zsb) == 0);
 
@@ -1221,6 +1250,9 @@ zfs_domount(struct super_block *sb, void *data, int silent)
 		if ((error = dsl_prop_get_integer(osname,"xattr",&pval,NULL)))
 			goto out;
 		xattr_changed_cb(zsb, pval);
+		if ((error = dsl_prop_get_integer(osname,"acltype",&pval,NULL)))
+			goto out;
+		acltype_changed_cb(zsb, pval);
 		zsb->z_issnap = B_TRUE;
 		zsb->z_os->os_sync = ZFS_SYNC_DISABLED;
 
@@ -1610,6 +1642,9 @@ zfs_get_zplprop(objset_t *os, zfs_prop_t prop, uint64_t *value)
 		case ZFS_PROP_CASE:
 			*value = ZFS_CASE_SENSITIVE;
 			break;
+		case ZFS_PROP_ACLTYPE:
+			*value = ZFS_ACLTYPE_OFF;
+			break;
 		default:
 			return (error);
 		}
@@ -1632,6 +1667,7 @@ zfs_init(void)
 void
 zfs_fini(void)
 {
+	taskq_wait(system_taskq);
 	unregister_filesystem(&zpl_fs_type);
 	zfs_znode_fini();
 	zfsctl_fini();