Honor CONFIG_FS_POSIX_ACL kernel option

The required Posix ACL interfaces are only available for kernels
with CONFIG_FS_POSIX_ACL defined.  Therefore, only enable Posix
ACL support for these kernels.  All major distribution kernels
enable CONFIG_FS_POSIX_ACL by default.

If your kernel does not support Posix ACLs the following warning
will be printed at ZFS module load time.

  "ZFS: Posix ACLs disabled by kernel"

Signed-off-by: Massimo Maggi <me@massimo-maggi.eu>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1825

include/linux/vfs_compat.h

@@ -174,6 +174,7 @@ lseek_execute(struct file *filp, struct inode *inode,
 }
 #endif /* SEEK_HOLE && SEEK_DATA && !HAVE_LSEEK_EXECUTE */
 
+#if defined(CONFIG_FS_POSIX_ACL)
 /*
  * These functions safely approximates the behavior of posix_acl_release()
  * which cannot be used because it calls the GPL-only symbol kfree_rcu().
@@ -315,5 +316,6 @@ typedef umode_t zpl_equivmode_t;
 #else
 typedef mode_t zpl_equivmode_t;
 #endif /* HAVE_POSIX_ACL_EQUIV_MODE_UMODE_T */
+#endif /* CONFIG_FS_POSIX_ACL */
 
 #endif /* _ZFS_VFS_H */

include/sys/zpl.h

@@ -71,6 +71,7 @@ extern struct file_system_type zpl_fs_type;
 extern ssize_t zpl_xattr_list(struct dentry *dentry, char *buf, size_t size);
 extern int zpl_xattr_security_init(struct inode *ip, struct inode *dip,
     const struct qstr *qstr);
+#if defined(CONFIG_FS_POSIX_ACL)
 extern int zpl_set_acl(struct inode *ip, int type, struct posix_acl *acl);
 extern struct posix_acl *zpl_get_acl(struct inode *ip, int type);
 #if !defined(HAVE_GET_ACL)
@@ -87,6 +88,19 @@ extern int zpl_permission(struct inode *ip, int mask);
 
 extern int zpl_init_acl(struct inode *ip, struct inode *dir);
 extern int zpl_chmod_acl(struct inode *ip);
+#else
+static inline int
+zpl_init_acl(struct inode *ip, struct inode *dir)
+{
+	return (0);
+}
+
+static inline int
+zpl_chmod_acl(struct inode *ip)
+{
+	return (0);
+}
+#endif /* CONFIG_FS_POSIX_ACL */
 
 extern xattr_handler_t *zpl_xattr_handlers[];
 

module/zfs/zfs_ioctl.c

@@ -5814,6 +5814,9 @@ _init(void)
 	       "ZFS pool version %s, ZFS filesystem version %s\n",
 	       ZFS_META_VERSION, ZFS_META_RELEASE, ZFS_DEBUG_STR,
 	       SPA_VERSION_STRING, ZPL_VERSION_STRING);
+#ifndef CONFIG_FS_POSIX_ACL
+	printk(KERN_NOTICE "ZFS: Posix ACLs disabled by kernel\n");
+#endif /* CONFIG_FS_POSIX_ACL */
 
 	return (0);
 

module/zfs/zfs_vfsops.c

@@ -165,8 +165,13 @@ acltype_changed_cb(void *arg, uint64_t newval)
 		zsb->z_sb->s_flags &= ~MS_POSIXACL;
 		break;
 	case ZFS_ACLTYPE_POSIXACL:
+#ifdef CONFIG_FS_POSIX_ACL
 		zsb->z_acl_type = ZFS_ACLTYPE_POSIXACL;
 		zsb->z_sb->s_flags |= MS_POSIXACL;
+#else
+		zsb->z_acl_type = ZFS_ACLTYPE_OFF;
+		zsb->z_sb->s_flags &= ~MS_POSIXACL;
+#endif /* CONFIG_FS_POSIX_ACL */
 		break;
 	default:
 		break;

module/zfs/zpl_inode.c

@@ -462,6 +462,7 @@ const struct inode_operations zpl_inode_operations = {
 #ifdef HAVE_INODE_FALLOCATE
 	.fallocate	= zpl_fallocate,
 #endif /* HAVE_INODE_FALLOCATE */
+#if defined(CONFIG_FS_POSIX_ACL)
 #if defined(HAVE_GET_ACL)
 	.get_acl	= zpl_get_acl,
 #elif defined(HAVE_CHECK_ACL)
@@ -469,6 +470,7 @@ const struct inode_operations zpl_inode_operations = {
 #elif defined(HAVE_PERMISSION)
 	.permission	= zpl_permission,
 #endif /* HAVE_GET_ACL | HAVE_CHECK_ACL | HAVE_PERMISSION */
+#endif /* CONFIG_FS_POSIX_ACL */
 };
 
 const struct inode_operations zpl_dir_inode_operations = {
@@ -487,6 +489,7 @@ const struct inode_operations zpl_dir_inode_operations = {
 	.getxattr	= generic_getxattr,
 	.removexattr	= generic_removexattr,
 	.listxattr	= zpl_xattr_list,
+#if defined(CONFIG_FS_POSIX_ACL)
 #if defined(HAVE_GET_ACL)
 	.get_acl	= zpl_get_acl,
 #elif defined(HAVE_CHECK_ACL)
@@ -494,6 +497,7 @@ const struct inode_operations zpl_dir_inode_operations = {
 #elif defined(HAVE_PERMISSION)
 	.permission	= zpl_permission,
 #endif /* HAVE_GET_ACL | HAVE_CHECK_ACL | HAVE_PERMISSION */
+#endif /* CONFIG_FS_POSIX_ACL */
 };
 
 const struct inode_operations zpl_symlink_inode_operations = {
@@ -515,6 +519,7 @@ const struct inode_operations zpl_special_inode_operations = {
 	.getxattr	= generic_getxattr,
 	.removexattr	= generic_removexattr,
 	.listxattr	= zpl_xattr_list,
+#if defined(CONFIG_FS_POSIX_ACL)
 #if defined(HAVE_GET_ACL)
 	.get_acl	= zpl_get_acl,
 #elif defined(HAVE_CHECK_ACL)
@@ -522,6 +527,7 @@ const struct inode_operations zpl_special_inode_operations = {
 #elif defined(HAVE_PERMISSION)
 	.permission	= zpl_permission,
 #endif /* HAVE_GET_ACL | HAVE_CHECK_ACL | HAVE_PERMISSION */
+#endif /* CONFIG_FS_POSIX_ACL */
 };
 
 dentry_operations_t zpl_dentry_operations = {

module/zfs/zpl_super.c

@@ -198,6 +198,7 @@ __zpl_show_options(struct seq_file *seq, zfs_sb_t *zsb)
 {
 	seq_printf(seq, ",%s", zsb->z_flags & ZSB_XATTR ? "xattr" : "noxattr");
 
+#ifdef CONFIG_FS_POSIX_ACL
 	switch (zsb->z_acl_type) {
 	case ZFS_ACLTYPE_POSIXACL:
 		seq_puts(seq, ",posixacl");
@@ -206,6 +207,7 @@ __zpl_show_options(struct seq_file *seq, zfs_sb_t *zsb)
 		seq_puts(seq, ",noacl");
 		break;
 	}
+#endif /* CONFIG_FS_POSIX_ACL */
 
 	return (0);
 }

module/zfs/zpl_xattr.c

@@ -722,6 +722,8 @@ xattr_handler_t zpl_xattr_security_handler = {
 	.set	= zpl_xattr_security_set,
 };
 
+#ifdef CONFIG_FS_POSIX_ACL
+
 int
 zpl_set_acl(struct inode *ip, int type, struct posix_acl *acl)
 {
@@ -1187,11 +1189,15 @@ struct xattr_handler zpl_xattr_acl_default_handler =
 #endif /* HAVE_DENTRY_XATTR_LIST */
 };
 
+#endif /* CONFIG_FS_POSIX_ACL */
+
 xattr_handler_t *zpl_xattr_handlers[] = {
 	&zpl_xattr_security_handler,
 	&zpl_xattr_trusted_handler,
 	&zpl_xattr_user_handler,
+#ifdef CONFIG_FS_POSIX_ACL
 	&zpl_xattr_acl_access_handler,
 	&zpl_xattr_acl_default_handler,
+#endif /* CONFIG_FS_POSIX_ACL */
 	NULL
 };