zfs/include/linux/dcache_compat.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright (C) 2011 Lawrence Livermore National Security, LLC.
  24  */
  25
  26 #ifndef _ZFS_DCACHE_H
  27 #define _ZFS_DCACHE_H
  28
  29 #include <linux/dcache.h>
  30
  31 #define dname(dentry)   ((char *)((dentry)->d_name.name))
  32 #define dlen(dentry)    ((int)((dentry)->d_name.len))
  33
  34 #ifndef HAVE_D_MAKE_ROOT
  35 #define d_make_root(inode)      d_alloc_root(inode)
  36 #endif /* HAVE_D_MAKE_ROOT */
  37
  38 /*
  39  * 2.6.30 API change,
  40  * The const keyword was added to the 'struct dentry_operations' in
  41  * the dentry structure.  To handle this we define an appropriate
  42  * dentry_operations_t typedef which can be used.
  43  */
  44 #ifdef HAVE_CONST_DENTRY_OPERATIONS
  45 typedef const struct dentry_operations  dentry_operations_t;
  46 #else
  47 typedef struct dentry_operations        dentry_operations_t;
  48 #endif
  49
  50 /*
  51  * 2.6.38 API change,
  52  * Added d_set_d_op() helper function which sets some flags in
  53  * dentry->d_flags based on which operations are defined.
  54  */
  55 #ifndef HAVE_D_SET_D_OP
  56 static inline void
  57 d_set_d_op(struct dentry *dentry, dentry_operations_t *op)
  58 {
  59         dentry->d_op = op;
  60 }
  61 #endif /* HAVE_D_SET_D_OP */
  62
  63 /*
  64  * 2.6.38 API addition,
  65  * Added d_clear_d_op() helper function which clears some flags and the
  66  * registered dentry->d_op table.  This is required because d_set_d_op()
  67  * issues a warning when the dentry operations table is already set.
  68  * For the .zfs control directory to work properly we must be able to
  69  * override the default operations table and register custom .d_automount
  70  * and .d_revalidate callbacks.
  71  */
  72 static inline void
  73 d_clear_d_op(struct dentry *dentry)
  74 {
  75 #ifdef HAVE_D_SET_D_OP
  76         dentry->d_op = NULL;
  77         dentry->d_flags &= ~(
  78             DCACHE_OP_HASH | DCACHE_OP_COMPARE |
  79             DCACHE_OP_REVALIDATE | DCACHE_OP_DELETE);
  80 #endif /* HAVE_D_SET_D_OP */
  81 }
  82
  83 #endif /* _ZFS_DCACHE_H */