--- /dev/null
+dnl #
+dnl # 3.6 API change
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_D_REVALIDATE_NAMEIDATA], [
+ AC_MSG_CHECKING([whether dops->d_revalidate() takes struct nameidata])
+ ZFS_LINUX_TRY_COMPILE([
+ #include <linux/dcache.h>
+ ],[
+ int (*revalidate) (struct dentry *, struct nameidata *) = NULL;
+ struct dentry_operations dops __attribute__ ((unused)) = {
+ .d_revalidate = revalidate,
+ };
+ ],[
+ AC_MSG_RESULT(yes)
+ AC_DEFINE(HAVE_D_REVALIDATE_NAMEIDATA, 1,
+ [dops->d_revalidate() operation takes nameidata])
+ ],[
+ AC_MSG_RESULT(no)
+ ])
+])
+
+dnl #
+dnl # 2.6.30 API change
+dnl # The 'struct dentry_operations' was constified in the dentry structure.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_CONST_DENTRY_OPERATIONS], [
+ AC_MSG_CHECKING([whether dentry uses const struct dentry_operations])
+ ZFS_LINUX_TRY_COMPILE([
+ #include <linux/dcache.h>
+
+ const struct dentry_operations test_d_op = {
+ .d_revalidate = NULL,
+ };
+ ],[
+ struct dentry d __attribute__ ((unused));
+
+ d.d_op = &test_d_op;
+ ],[
+ AC_MSG_RESULT(yes)
+ AC_DEFINE(HAVE_CONST_DENTRY_OPERATIONS, 1,
+ [dentry uses const struct dentry_operations])
+ ],[
+ AC_MSG_RESULT(no)
+ ])
+])
+
+dnl #
+dnl # 2.6.38 API change
+dnl # Added d_set_d_op() helper function.
+dnl #
+AC_DEFUN([ZFS_AC_KERNEL_D_SET_D_OP],
+ [AC_MSG_CHECKING([whether d_set_d_op() is available])
+ ZFS_LINUX_TRY_COMPILE_SYMBOL([
+ #include <linux/dcache.h>
+ ], [
+ d_set_d_op(NULL, NULL);
+ ], [d_set_d_op], [fs/dcache.c], [
+ AC_MSG_RESULT(yes)
+ AC_DEFINE(HAVE_D_SET_D_OP, 1,
+ [d_set_d_op() is available])
+ ], [
+ AC_MSG_RESULT(no)
+ ])
+])
.getattr = zpl_root_getattr,
};
+#ifdef HAVE_AUTOMOUNT
+static struct vfsmount *
+zpl_snapdir_automount(struct path *path)
+{
+ struct dentry *dentry = path->dentry;
+ int error;
+
+ /*
+ * We must briefly disable automounts for this dentry because the
+ * user space mount utility will trigger another lookup on this
+ * directory. That will result in zpl_snapdir_automount() being
+ * called repeatedly. The DCACHE_NEED_AUTOMOUNT flag can be
+ * safely reset once the mount completes.
+ */
+ dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
+ error = -zfsctl_mount_snapshot(path, 0);
+ dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
+ if (error)
+ return ERR_PTR(error);
+
+ /*
+ * Rather than returning the new vfsmount for the snapshot we must
+ * return NULL to indicate a mount collision. This is done because
+ * the user space mount calls do_add_mount() which adds the vfsmount
+ * to the name space. If we returned the new mount here it would be
+ * added again to the vfsmount list resulting in list corruption.
+ */
+ return (NULL);
+}
+#endif /* HAVE_AUTOMOUNT */
+
+/*
+ * Revalidate any dentry in the snapshot directory on lookup, since a snapshot
+ * having the same name have been created or destroyed since it was cached.
+ */
+static int
+#ifdef HAVE_D_REVALIDATE_NAMEIDATA
+zpl_snapdir_revalidate(struct dentry *dentry, struct nameidata *i)
+#else
+zpl_snapdir_revalidate(struct dentry *dentry, unsigned int flags)
+#endif
+{
+ return 0;
+}
+
+dentry_operations_t zpl_dops_snapdirs = {
+/*
+ * Auto mounting of snapshots is only supported for 2.6.37 and
+ * newer kernels. Prior to this kernel the ops->follow_link()
+ * callback was used as a hack to trigger the mount. The
+ * resulting vfsmount was then explicitly grafted in to the
+ * name space. While it might be possible to add compatibility
+ * code to accomplish this it would require considerable care.
+ */
+#ifdef HAVE_AUTOMOUNT
+ .d_automount = zpl_snapdir_automount,
+#endif /* HAVE_AUTOMOUNT */
+ .d_revalidate = zpl_snapdir_revalidate,
+};
+
static struct dentry *
#ifdef HAVE_LOOKUP_NAMEIDATA
zpl_snapdir_lookup(struct inode *dip, struct dentry *dentry,
{
cred_t *cr = CRED();
- struct inode *ip;
+ struct inode *ip = NULL;
int error;
crhold(cr);
ASSERT3S(error, <=, 0);
crfree(cr);
- if (error) {
- if (error == -ENOENT)
- return d_splice_alias(NULL, dentry);
- else
- return ERR_PTR(error);
- }
+ if (error && error != -ENOENT)
+ return ERR_PTR(error);
- /*
- * Auto mounting of snapshots is only supported for 2.6.37 and
- * newer kernels. Prior to this kernel the ops->follow_link()
- * callback was used as a hack to trigger the mount. The
- * resulting vfsmount was then explicitly grafted in to the
- * name space. While it might be possible to add compatibility
- * code to accomplish this it would require considerable care.
- */
-#ifdef HAVE_AUTOMOUNT
- dentry->d_op = &zpl_dops_snapdirs;
-#endif /* HAVE_AUTOMOUNT */
+ ASSERT(error == 0 || ip == NULL);
+ d_set_d_op(dentry, &zpl_dops_snapdirs);
return d_splice_alias(ip, dentry);
}
error = -zfsctl_snapdir_mkdir(dip, dname(dentry), vap, &ip, cr, 0);
if (error == 0) {
-#ifdef HAVE_AUTOMOUNT
- dentry->d_op = &zpl_dops_snapdirs;
-#endif /* HAVE_AUTOMOUNT */
+ d_set_d_op(dentry, &zpl_dops_snapdirs);
d_instantiate(dentry, ip);
}
return (error);
}
-#ifdef HAVE_AUTOMOUNT
-static struct vfsmount *
-zpl_snapdir_automount(struct path *path)
-{
- struct dentry *dentry = path->dentry;
- int error;
-
- /*
- * We must briefly disable automounts for this dentry because the
- * user space mount utility will trigger another lookup on this
- * directory. That will result in zpl_snapdir_automount() being
- * called repeatedly. The DCACHE_NEED_AUTOMOUNT flag can be
- * safely reset once the mount completes.
- */
- dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
- error = -zfsctl_mount_snapshot(path, 0);
- dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
- if (error)
- return ERR_PTR(error);
-
- /*
- * Rather than returning the new vfsmount for the snapshot we must
- * return NULL to indicate a mount collision. This is done because
- * the user space mount calls do_add_mount() which adds the vfsmount
- * to the name space. If we returned the new mount here it would be
- * added again to the vfsmount list resulting in list corruption.
- */
- return (NULL);
-}
-#endif /* HAVE_AUTOMOUNT */
-
/*
* Get snapshot directory attributes.
*/
.mkdir = zpl_snapdir_mkdir,
};
-#ifdef HAVE_AUTOMOUNT
-const struct dentry_operations zpl_dops_snapdirs = {
- .d_automount = zpl_snapdir_automount,
-};
-#endif /* HAVE_AUTOMOUNT */
-
static struct dentry *
#ifdef HAVE_LOOKUP_NAMEIDATA
zpl_shares_lookup(struct inode *dip, struct dentry *dentry,
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