misc/fsmap.h

   1 /*
   2  * Copyright (c) 2017 Oracle.
   3  * All Rights Reserved.
   4  *
   5  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it would be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write the Free Software Foundation,
  18  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  */
  20 #ifndef FSMAP_H_
  21 #define FSMAP_H_
  22
  23 /* FS_IOC_GETFSMAP ioctl definitions */
  24 #ifndef FS_IOC_GETFSMAP
  25 struct fsmap {
  26         __u32           fmr_device;     /* device id */
  27         __u32           fmr_flags;      /* mapping flags */
  28         __u64           fmr_physical;   /* device offset of segment */
  29         __u64           fmr_owner;      /* owner id */
  30         __u64           fmr_offset;     /* file offset of segment */
  31         __u64           fmr_length;     /* length of segment */
  32         __u64           fmr_reserved[3];        /* must be zero */
  33 };
  34
  35 struct fsmap_head {
  36         __u32           fmh_iflags;     /* control flags */
  37         __u32           fmh_oflags;     /* output flags */
  38         __u32           fmh_count;      /* # of entries in array incl. input */
  39         __u32           fmh_entries;    /* # of entries filled in (output). */
  40         __u64           fmh_reserved[6];        /* must be zero */
  41
  42         struct fsmap    fmh_keys[2];    /* low and high keys for the mapping search */
  43         struct fsmap    fmh_recs[];     /* returned records */
  44 };
  45
  46 /* Size of an fsmap_head with room for nr records. */
  47 static inline size_t
  48 fsmap_sizeof(
  49         unsigned int    nr)
  50 {
  51         return sizeof(struct fsmap_head) + nr * sizeof(struct fsmap);
  52 }
  53
  54 /* Start the next fsmap query at the end of the current query results. */
  55 static inline void
  56 fsmap_advance(
  57         struct fsmap_head       *head)
  58 {
  59         head->fmh_keys[0] = head->fmh_recs[head->fmh_entries - 1];
  60 }
  61
  62 /*      fmh_iflags values - set by FS_IOC_GETFSMAP caller in the header. */
  63 /* no flags defined yet */
  64 #define FMH_IF_VALID            0
  65
  66 /*      fmh_oflags values - returned in the header segment only. */
  67 #define FMH_OF_DEV_T            0x1     /* fmr_device values will be dev_t */
  68
  69 /*      fmr_flags values - returned for each non-header segment */
  70 #define FMR_OF_PREALLOC         0x1     /* segment = unwritten pre-allocation */
  71 #define FMR_OF_ATTR_FORK        0x2     /* segment = attribute fork */
  72 #define FMR_OF_EXTENT_MAP       0x4     /* segment = extent map */
  73 #define FMR_OF_SHARED           0x8     /* segment = shared with another file */
  74 #define FMR_OF_SPECIAL_OWNER    0x10    /* owner is a special value */
  75 #define FMR_OF_LAST             0x20    /* segment is the last in the FS */
  76
  77 /* Each FS gets to define its own special owner codes. */
  78 #define FMR_OWNER(type, code)   (((__u64)type << 32) | \
  79                                  ((__u64)code & 0xFFFFFFFFULL))
  80 #define FMR_OWNER_TYPE(owner)   ((__u32)((__u64)owner >> 32))
  81 #define FMR_OWNER_CODE(owner)   ((__u32)(((__u64)owner & 0xFFFFFFFFULL)))
  82 #define FMR_OWN_FREE            FMR_OWNER(0, 1) /* free space */
  83 #define FMR_OWN_UNKNOWN         FMR_OWNER(0, 2) /* unknown owner */
  84 #define FMR_OWN_METADATA        FMR_OWNER(0, 3) /* metadata */
  85
  86 #define FS_IOC_GETFSMAP         _IOWR('X', 59, struct fsmap_head)
  87 #endif /* FS_IOC_GETFSMAP */
  88
  89 #endif