fs/xfs/xfs_iomap.h

   1 /*
   2  * Copyright (c) 2003-2005 Silicon Graphics, Inc.  All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of version 2 of the GNU General Public License as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it would be useful, but
   9  * WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11  *
  12  * Further, this software is distributed without any warranty that it is
  13  * free of the rightful claim of any third person regarding infringement
  14  * or the like.  Any license provided herein, whether implied or
  15  * otherwise, applies only to this software file.  Patent licenses, if
  16  * any, provided herein do not apply to combinations of this program with
  17  * other software, or any other product whatsoever.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; if not, write the Free Software Foundation, Inc., 59
  21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
  22  *
  23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
  24  * Mountain View, CA  94043, or:
  25  *
  26  * http://www.sgi.com
  27  *
  28  * For further information regarding this notice, see:
  29  *
  30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
  31  */
  32 #ifndef __XFS_IOMAP_H__
  33 #define __XFS_IOMAP_H__
  34
  35 #define IOMAP_DADDR_NULL ((xfs_daddr_t) (-1LL))
  36
  37
  38 typedef enum {                          /* iomap_flags values */
  39         IOMAP_EOF =             0x01,   /* mapping contains EOF   */
  40         IOMAP_HOLE =            0x02,   /* mapping covers a hole  */
  41         IOMAP_DELAY =           0x04,   /* mapping covers delalloc region  */
  42         IOMAP_REALTIME =        0x10,   /* mapping on the realtime device  */
  43         IOMAP_UNWRITTEN =       0x20,   /* mapping covers allocated */
  44                                         /* but uninitialized file data  */
  45         IOMAP_NEW =             0x40    /* just allocate */
  46 } iomap_flags_t;
  47
  48 typedef enum {
  49         /* base extent manipulation calls */
  50         BMAPI_READ = (1 << 0),          /* read extents */
  51         BMAPI_WRITE = (1 << 1),         /* create extents */
  52         BMAPI_ALLOCATE = (1 << 2),      /* delayed allocate to real extents */
  53         BMAPI_UNWRITTEN  = (1 << 3),    /* unwritten extents to real extents */
  54         /* modifiers */
  55         BMAPI_IGNSTATE = (1 << 4),      /* ignore unwritten state on read */
  56         BMAPI_DIRECT = (1 << 5),        /* direct instead of buffered write */
  57         BMAPI_MMAP = (1 << 6),          /* allocate for mmap write */
  58         BMAPI_SYNC = (1 << 7),          /* sync write to flush delalloc space */
  59         BMAPI_TRYLOCK = (1 << 8),       /* non-blocking request */
  60         BMAPI_DEVICE = (1 << 9),        /* we only want to know the device */
  61 } bmapi_flags_t;
  62
  63
  64 /*
  65  * xfs_iomap_t:  File system I/O map
  66  *
  67  * The iomap_bn field is expressed in 512-byte blocks, and is where the
  68  * mapping starts on disk.
  69  *
  70  * The iomap_offset, iomap_bsize and iomap_delta fields are in bytes.
  71  * iomap_offset is the offset of the mapping in the file itself.
  72  * iomap_bsize is the size of the mapping,  iomap_delta is the
  73  * desired data's offset into the mapping, given the offset supplied
  74  * to the file I/O map routine.
  75  *
  76  * When a request is made to read beyond the logical end of the object,
  77  * iomap_size may be set to 0, but iomap_offset and iomap_length should be set
  78  * to the actual amount of underlying storage that has been allocated, if any.
  79  */
  80
  81 typedef struct xfs_iomap {
  82         xfs_daddr_t             iomap_bn;       /* first 512b blk of mapping */
  83         xfs_buftarg_t           *iomap_target;
  84         xfs_off_t               iomap_offset;   /* offset of mapping, bytes */
  85         xfs_off_t               iomap_bsize;    /* size of mapping, bytes */
  86         size_t                  iomap_delta;    /* offset into mapping, bytes */
  87         iomap_flags_t           iomap_flags;
  88 } xfs_iomap_t;
  89
  90 struct xfs_iocore;
  91 struct xfs_inode;
  92 struct xfs_bmbt_irec;
  93
  94 extern int xfs_iomap(struct xfs_iocore *, xfs_off_t, ssize_t, int,
  95                      struct xfs_iomap *, int *);
  96 extern int xfs_iomap_write_direct(struct xfs_inode *, xfs_off_t, size_t,
  97                                   int, struct xfs_bmbt_irec *, int *, int);
  98 extern int xfs_iomap_write_delay(struct xfs_inode *, xfs_off_t, size_t, int,
  99                                  struct xfs_bmbt_irec *, int *);
 100 extern int xfs_iomap_write_allocate(struct xfs_inode *, xfs_off_t, size_t,
 101                                 struct xfs_bmbt_irec *, int *);
 102 extern int xfs_iomap_write_unwritten(struct xfs_inode *, xfs_off_t, size_t);
 103
 104 #endif /* __XFS_IOMAP_H__*/