config/kernel-get-link.m4

   1 dnl #
   2 dnl # Supported get_link() interfaces checked newest to oldest.
   3 dnl # Note this interface used to be named follow_link.
   4 dnl #
   5 AC_DEFUN([ZFS_AC_KERNEL_SRC_GET_LINK], [
   6         ZFS_LINUX_TEST_SRC([inode_operations_get_link], [
   7                 #include <linux/fs.h>
   8                 const char *get_link(struct dentry *de, struct inode *ip,
   9                     struct delayed_call *done) { return "symlink"; }
  10                 static struct inode_operations
  11                      iops __attribute__ ((unused)) = {
  12                         .get_link = get_link,
  13                 };
  14         ],[])
  15
  16         ZFS_LINUX_TEST_SRC([inode_operations_get_link_cookie], [
  17                 #include <linux/fs.h>
  18                 const char *get_link(struct dentry *de, struct
  19                     inode *ip, void **cookie) { return "symlink"; }
  20                 static struct inode_operations
  21                      iops __attribute__ ((unused)) = {
  22                         .get_link = get_link,
  23                 };
  24         ],[])
  25
  26         ZFS_LINUX_TEST_SRC([inode_operations_follow_link], [
  27                 #include <linux/fs.h>
  28                 const char *follow_link(struct dentry *de,
  29                     void **cookie) { return "symlink"; }
  30                 static struct inode_operations
  31                     iops __attribute__ ((unused)) = {
  32                         .follow_link = follow_link,
  33                 };
  34         ],[])
  35
  36         ZFS_LINUX_TEST_SRC([inode_operations_follow_link_nameidata], [
  37                 #include <linux/fs.h>
  38                 void *follow_link(struct dentry *de, struct
  39                     nameidata *nd) { return (void *)NULL; }
  40                 static struct inode_operations
  41                     iops __attribute__ ((unused)) = {
  42                         .follow_link = follow_link,
  43                 };
  44         ],[])
  45 ])
  46
  47 AC_DEFUN([ZFS_AC_KERNEL_GET_LINK], [
  48         dnl #
  49         dnl # 4.5 API change
  50         dnl # The get_link interface has added a delayed done call and
  51         dnl # used it to retire the put_link() interface.
  52         dnl #
  53         AC_MSG_CHECKING([whether iops->get_link() passes delayed])
  54         ZFS_LINUX_TEST_RESULT([inode_operations_get_link], [
  55                 AC_MSG_RESULT(yes)
  56                 AC_DEFINE(HAVE_GET_LINK_DELAYED, 1, [iops->get_link() delayed])
  57         ],[
  58                 AC_MSG_RESULT(no)
  59
  60                 dnl #
  61                 dnl # 4.5 API change
  62                 dnl # The follow_link() interface has been replaced by
  63                 dnl # get_link() which behaves the same as before except:
  64                 dnl # - An inode is passed as a separate argument
  65                 dnl # - When called in RCU mode a NULL dentry is passed.
  66                 dnl #
  67                 AC_MSG_CHECKING([whether iops->get_link() passes cookie])
  68                 ZFS_LINUX_TEST_RESULT([inode_operations_get_link_cookie], [
  69                         AC_MSG_RESULT(yes)
  70                         AC_DEFINE(HAVE_GET_LINK_COOKIE, 1,
  71                             [iops->get_link() cookie])
  72                 ],[
  73                         AC_MSG_RESULT(no)
  74
  75                         dnl #
  76                         dnl # 4.2 API change
  77                         dnl # This kernel retired the nameidata structure.
  78                         dnl #
  79                         AC_MSG_CHECKING(
  80                             [whether iops->follow_link() passes cookie])
  81                         ZFS_LINUX_TEST_RESULT([inode_operations_follow_link], [
  82                                 AC_MSG_RESULT(yes)
  83                                 AC_DEFINE(HAVE_FOLLOW_LINK_COOKIE, 1,
  84                                     [iops->follow_link() cookie])
  85                         ],[
  86                                 AC_MSG_RESULT(no)
  87
  88                                 dnl #
  89                                 dnl # 2.6.32 API
  90                                 dnl #
  91                                 AC_MSG_CHECKING(
  92                                 [whether iops->follow_link() passes nameidata])
  93                                 ZFS_LINUX_TEST_RESULT(
  94                                     [inode_operations_follow_link_nameidata],[
  95                                         AC_MSG_RESULT(yes)
  96                                         AC_DEFINE(HAVE_FOLLOW_LINK_NAMEIDATA, 1,
  97                                             [iops->follow_link() nameidata])
  98                                 ],[
  99                                         ZFS_LINUX_TEST_ERROR([get_link])
 100                                 ])
 101                         ])
 102                 ])
 103         ])
 104 ])