Possibility to physically reserve space without writing leaf blocks

          --- old/usr/src/common/zfs/zfeature_common.h
          +++ new/usr/src/common/zfs/zfeature_common.h

   1    1  /*
   2    2   * CDDL HEADER START
   3    3   *
   4    4   * The contents of this file are subject to the terms of the
   5    5   * Common Development and Distribution License (the "License").
   6    6   * You may not use this file except in compliance with the License.
   7    7   *
   8    8   * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9    9   * or http://www.opensolaris.org/os/licensing.
  10   10   * See the License for the specific language governing permissions
  11   11   * and limitations under the License.
  12   12   *
  13   13   * When distributing Covered Code, include this CDDL HEADER in each
  14   14   * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15   15   * If applicable, add the following below this CDDL HEADER, with the
  16   16   * fields enclosed by brackets "[]" replaced with your own identifying
  17   17   * information: Portions Copyright [yyyy] [name of copyright owner]
  18   18   *
  19   19   * CDDL HEADER END
  20   20   */
  21   21  
  22   22  /*
  23   23   * Copyright (c) 2013 by Delphix. All rights reserved.
  24   24   * Copyright (c) 2013 by Saso Kiselkov. All rights reserved.
  25   25   * Copyright (c) 2013, Joyent, Inc. All rights reserved.
  26   26   */
  27   27  
  28   28  #ifndef _ZFEATURE_COMMON_H
  29   29  #define _ZFEATURE_COMMON_H
  30   30  
  31   31  #include <sys/fs/zfs.h>
  32   32  #include <sys/inttypes.h>
  33   33  #include <sys/types.h>
  34   34  
  35   35  #ifdef  __cplusplus
  36   36  extern "C" {
  37   37  #endif
  38   38  
  39   39  struct zfeature_info;
  40   40  
  41   41  typedef enum spa_feature {
  42   42          SPA_FEATURE_NONE = -1,
  43   43          SPA_FEATURE_ASYNC_DESTROY,

  44   44          SPA_FEATURE_EMPTY_BPOBJ,
  45   45          SPA_FEATURE_LZ4_COMPRESS,
  46   46          SPA_FEATURE_MULTI_VDEV_CRASH_DUMP,
  47   47          SPA_FEATURE_SPACEMAP_HISTOGRAM,
  48   48          SPA_FEATURE_ENABLED_TXG,
  49   49          SPA_FEATURE_HOLE_BIRTH,
  50   50          SPA_FEATURE_EXTENSIBLE_DATASET,
  51   51          SPA_FEATURE_EMBEDDED_DATA,
  52   52          SPA_FEATURE_BOOKMARKS,
  53   53          SPA_FEATURE_FS_SS_LIMIT,
       54 +        SPA_FEATURE_SPACE_RESERVATION,
  54   55          SPA_FEATURES
  55   56  } spa_feature_t;
  56   57  
  57   58  #define SPA_FEATURE_DISABLED    (-1ULL)
  58   59  
  59   60  typedef struct zfeature_info {
  60   61          spa_feature_t fi_feature;
  61   62          const char *fi_uname;   /* User-facing feature name */
  62   63          const char *fi_guid;    /* On-disk feature identifier */
  63   64          const char *fi_desc;    /* Feature description */

  64   65          boolean_t fi_can_readonly; /* Can open pool readonly w/o support? */
  65   66          boolean_t fi_mos;       /* Is the feature necessary to read the MOS? */
  66   67          /* Activate this feature at the same time it is enabled */
  67   68          boolean_t fi_activate_on_enable;
  68   69          /* array of dependencies, terminated by SPA_FEATURE_NONE */
  69   70          const spa_feature_t *fi_depends;
  70   71  } zfeature_info_t;
  71   72  
  72   73  typedef int (zfeature_func_t)(zfeature_info_t *, void *);
  73   74  
  74   75  #define ZFS_FEATURE_DEBUG
  75   76  
  76   77  extern zfeature_info_t spa_feature_table[SPA_FEATURES];
  77   78  
  78   79  extern boolean_t zfeature_is_valid_guid(const char *);
  79   80  
  80   81  extern boolean_t zfeature_is_supported(const char *);
  81   82  extern int zfeature_lookup_name(const char *, spa_feature_t *);
  82   83  extern boolean_t zfeature_depends_on(spa_feature_t, spa_feature_t);
  83   84  
  84   85  extern void zpool_feature_init(void);
  85   86  
  86   87  #ifdef  __cplusplus
  87   88  }
  88   89  #endif
  89   90  
  90   91  #endif  /* _ZFEATURE_COMMON_H */

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