usr/src/uts/common/sys/fssnap_if.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, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #ifndef _SYS_FSSNAP_IF_H
  28 #define _SYS_FSSNAP_IF_H
  29
  30 #pragma ident   "%Z%%M% %I%     %E% SMI"
  31
  32 #include <sys/types.h>
  33 #include <sys/fssnap.h>
  34
  35 #ifdef  __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 /*
  40  * ioctl's for communicating between the user and the fssnapctl device.
  41  * Also used to communicate between fssnapctl and the file system.
  42  * Pack fiosnapcreate for amd64 to make struct size same as x86.
  43  */
  44
  45 #if _LONG_LONG_ALIGNMENT == 8 && _LONG_LONG_ALIGNMENT_32 == 4
  46 #pragma pack(4)
  47 #endif
  48
  49 struct fiosnapcreate {
  50         int     rootfiledesc;   /* IN  fd for root of fs to be snapshotted */
  51         int     backfiledesc;   /* IN  backing store file for snapshot data */
  52         uint_t  snapshotnumber; /* OUT snapshot number created */
  53         uint_t  chunksize;      /* IN  chunk size, 0 == fs defined */
  54         u_offset_t      maxsize; /* IN  maximum size of backing file */
  55         char    backfilename[MAXPATHLEN];       /* IN  for bookkeeping */
  56         int     error;          /* OUT error code */
  57 };
  58
  59 struct fiosnapcreate_multi {
  60         int     rootfiledesc;   /* IN  fd for root of fs to be snapshotted */
  61         uint_t  snapshotnumber; /* OUT snapshot number created */
  62         uint_t  chunksize;      /* IN  chunk size, 0 == fs defined */
  63         u_offset_t      maxsize; /* IN  max size of entire backing store */
  64         char    backfilename[MAXPATHLEN];       /* IN  for bookkeeping */
  65         int     error;          /* OUT error code */
  66         int     backfilecount;  /* IN  number of backing store files */
  67         u_offset_t      backfilesize; /* IN maximum size of each backfile */
  68         int     backfiledesc[1]; /* IN  backing store files for snapshot data */
  69 };
  70
  71 #if _LONG_LONG_ALIGNMENT == 8 && _LONG_LONG_ALIGNMENT_32 == 4
  72 #pragma pack()
  73 #endif
  74
  75 struct fiosnapdelete {
  76         int     rootfiledesc;   /* IN  fd for root of fs to be unsnapshotted */
  77         uint_t  snapshotnumber; /* OUT snapshot number deleted */
  78         int     error;          /* OUT error code */
  79 };
  80
  81 /* ioctl error returns */
  82 #define FIOCOW_EREADONLY (1)    /* read only file system */
  83 #define FIOCOW_EBUSY    (2)     /* snapshot already enabled */
  84 #define FIOCOW_EULOCK   (3)     /* file system is locked */
  85 #define FIOCOW_EWLOCK   (4)     /* file system could not be write locked */
  86 #define FIOCOW_EFLUSH   (5)     /* file system could not be flushed */
  87 #define FIOCOW_ECLEAN   (6)     /* file system may not be stable */
  88 #define FIOCOW_ENOULOCK (7)     /* file system could not be unlocked */
  89 #define FIOCOW_ECHUNKSZ (8)     /* chunksize is less than fs fragment size */
  90 #define FIOCOW_ECREATE  (9)     /* could not allocate/create snapshot */
  91 #define FIOCOW_EBITMAP  (10)    /* error scanning file system bitmaps */
  92 #define FIOCOW_EBACKFILE (11)   /* bad backing file path passed in */
  93
  94 /*
  95  * make the control device minor number high so minor numbers match
  96  * snapshot numbers.
  97  */
  98 #define SNAP_CTL_MINOR  (L_MAXMIN32)
  99 #define SNAP_NAME       "fssnap"
 100 #define SNAP_CTL_NODE   "ctl"
 101 #define SNAP_CTL_NAME   SNAP_NAME SNAP_CTL_NODE
 102 #define SNAP_BLOCK_NAME SNAP_NAME
 103 #define SNAP_CHAR_NAME  "r" SNAP_NAME
 104
 105 /* kstat names */
 106 #define FSSNAP_KSTAT_HIGHWATER          "highwater"
 107 #define FSSNAP_KSTAT_MNTPT              "mountpoint"
 108 #define FSSNAP_KSTAT_BFNAME             "bfname"
 109 #define FSSNAP_KSTAT_NUM                "numericstats"
 110
 111 /* numericstats kstat names */
 112 #define FSSNAP_KSTAT_NUM_STATE          "state"
 113 #define FSSNAP_KSTAT_NUM_BFSIZE         "bfsize"
 114 #define FSSNAP_KSTAT_NUM_MAXSIZE        "maxsize"
 115 #define FSSNAP_KSTAT_NUM_CHUNKSIZE      "chunksize"
 116 #define FSSNAP_KSTAT_NUM_CREATETIME     "createtime"
 117
 118 #if defined(_KERNEL)
 119 /*
 120  * snapshot operations implemented by the loadable snapshot subsystem
 121  */
 122 struct fssnap_operations {
 123         void *(*fssnap_create)(chunknumber_t, uint_t, u_offset_t,
 124             struct vnode *, int, struct vnode **, char *, u_offset_t);
 125         void (*fssnap_set_candidate)(void *, chunknumber_t);
 126         int (*fssnap_is_candidate)(void *, u_offset_t);
 127         int  (*fssnap_create_done)(void *);
 128         int (*fssnap_delete)(void *);
 129         void (*fssnap_strategy)(void *, struct buf *);
 130 };
 131
 132
 133 /* global variables to manage interface operations */
 134 extern struct fssnap_operations snapops;
 135
 136 /* External functions called by file systems that use snapshots */
 137 extern int fssnap_init(void);
 138 extern int fssnap_fini(void);
 139 extern void *fssnap_create(chunknumber_t, uint_t, u_offset_t, struct vnode *,
 140     int, struct vnode **, char *, u_offset_t);
 141 extern void fssnap_set_candidate(void *, chunknumber_t);
 142 extern int fssnap_is_candidate(void *, u_offset_t);
 143 extern int  fssnap_create_done(void *);
 144 extern int fssnap_delete(void *);
 145 extern void fssnap_strategy(void *, struct buf *);
 146
 147 #endif /* _KERNEL */
 148
 149 #ifdef  __cplusplus
 150 }
 151 #endif
 152
 153 #endif /* _SYS_FSSNAP_IF_H */