fs/xfs/xfs_bmap.h

   1 /*
   2  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
   3  * All Rights Reserved.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it would be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write the Free Software Foundation,
  16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17  */
  18 #ifndef __XFS_BMAP_H__
  19 #define __XFS_BMAP_H__
  20
  21 struct getbmap;
  22 struct xfs_bmbt_irec;
  23 struct xfs_ifork;
  24 struct xfs_inode;
  25 struct xfs_mount;
  26 struct xfs_trans;
  27
  28 extern kmem_zone_t      *xfs_bmap_free_item_zone;
  29
  30 /*
  31  * List of extents to be free "later".
  32  * The list is kept sorted on xbf_startblock.
  33  */
  34 typedef struct xfs_bmap_free_item
  35 {
  36         xfs_fsblock_t           xbfi_startblock;/* starting fs block number */
  37         xfs_extlen_t            xbfi_blockcount;/* number of blocks in extent */
  38         struct xfs_bmap_free_item *xbfi_next;   /* link to next entry */
  39 } xfs_bmap_free_item_t;
  40
  41 /*
  42  * Header for free extent list.
  43  *
  44  * xbf_low is used by the allocator to activate the lowspace algorithm -
  45  * when free space is running low the extent allocator may choose to
  46  * allocate an extent from an AG without leaving sufficient space for
  47  * a btree split when inserting the new extent.  In this case the allocator
  48  * will enable the lowspace algorithm which is supposed to allow further
  49  * allocations (such as btree splits and newroots) to allocate from
  50  * sequential AGs.  In order to avoid locking AGs out of order the lowspace
  51  * algorithm will start searching for free space from AG 0.  If the correct
  52  * transaction reservations have been made then this algorithm will eventually
  53  * find all the space it needs.
  54  */
  55 typedef struct xfs_bmap_free
  56 {
  57         xfs_bmap_free_item_t    *xbf_first;     /* list of to-be-free extents */
  58         int                     xbf_count;      /* count of items on list */
  59         int                     xbf_low;        /* alloc in low mode */
  60 } xfs_bmap_free_t;
  61
  62 #define XFS_BMAP_MAX_NMAP       4
  63
  64 /*
  65  * Flags for xfs_bmapi_*
  66  */
  67 #define XFS_BMAPI_ENTIRE        0x001   /* return entire extent, not trimmed */
  68 #define XFS_BMAPI_METADATA      0x002   /* mapping metadata not user data */
  69 #define XFS_BMAPI_ATTRFORK      0x004   /* use attribute fork not data */
  70 #define XFS_BMAPI_PREALLOC      0x008   /* preallocation op: unwritten space */
  71 #define XFS_BMAPI_IGSTATE       0x010   /* Ignore state - */
  72                                         /* combine contig. space */
  73 #define XFS_BMAPI_CONTIG        0x020   /* must allocate only one extent */
  74 /*
  75  * unwritten extent conversion - this needs write cache flushing and no additional
  76  * allocation alignments. When specified with XFS_BMAPI_PREALLOC it converts
  77  * from written to unwritten, otherwise convert from unwritten to written.
  78  */
  79 #define XFS_BMAPI_CONVERT       0x040
  80 #define XFS_BMAPI_STACK_SWITCH  0x080
  81
  82 #define XFS_BMAPI_FLAGS \
  83         { XFS_BMAPI_ENTIRE,     "ENTIRE" }, \
  84         { XFS_BMAPI_METADATA,   "METADATA" }, \
  85         { XFS_BMAPI_ATTRFORK,   "ATTRFORK" }, \
  86         { XFS_BMAPI_PREALLOC,   "PREALLOC" }, \
  87         { XFS_BMAPI_IGSTATE,    "IGSTATE" }, \
  88         { XFS_BMAPI_CONTIG,     "CONTIG" }, \
  89         { XFS_BMAPI_CONVERT,    "CONVERT" }, \
  90         { XFS_BMAPI_STACK_SWITCH, "STACK_SWITCH" }
  91
  92
  93 static inline int xfs_bmapi_aflag(int w)
  94 {
  95         return (w == XFS_ATTR_FORK ? XFS_BMAPI_ATTRFORK : 0);
  96 }
  97
  98 /*
  99  * Special values for xfs_bmbt_irec_t br_startblock field.
 100  */
 101 #define DELAYSTARTBLOCK         ((xfs_fsblock_t)-1LL)
 102 #define HOLESTARTBLOCK          ((xfs_fsblock_t)-2LL)
 103
 104 static inline void xfs_bmap_init(xfs_bmap_free_t *flp, xfs_fsblock_t *fbp)
 105 {
 106         ((flp)->xbf_first = NULL, (flp)->xbf_count = 0, \
 107                 (flp)->xbf_low = 0, *(fbp) = NULLFSBLOCK);
 108 }
 109
 110 /*
 111  * Flags for xfs_bmap_add_extent*.
 112  */
 113 #define BMAP_LEFT_CONTIG        (1 << 0)
 114 #define BMAP_RIGHT_CONTIG       (1 << 1)
 115 #define BMAP_LEFT_FILLING       (1 << 2)
 116 #define BMAP_RIGHT_FILLING      (1 << 3)
 117 #define BMAP_LEFT_DELAY         (1 << 4)
 118 #define BMAP_RIGHT_DELAY        (1 << 5)
 119 #define BMAP_LEFT_VALID         (1 << 6)
 120 #define BMAP_RIGHT_VALID        (1 << 7)
 121 #define BMAP_ATTRFORK           (1 << 8)
 122
 123 #define XFS_BMAP_EXT_FLAGS \
 124         { BMAP_LEFT_CONTIG,     "LC" }, \
 125         { BMAP_RIGHT_CONTIG,    "RC" }, \
 126         { BMAP_LEFT_FILLING,    "LF" }, \
 127         { BMAP_RIGHT_FILLING,   "RF" }, \
 128         { BMAP_ATTRFORK,        "ATTR" }
 129
 130
 131 /*
 132  * This macro is used to determine how many extents will be shifted
 133  * in one write transaction. We could require two splits,
 134  * an extent move on the first and an extent merge on the second,
 135  * So it is proper that one extent is shifted inside write transaction
 136  * at a time.
 137  */
 138 #define XFS_BMAP_MAX_SHIFT_EXTENTS      1
 139
 140 #ifdef DEBUG
 141 void    xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
 142                 int whichfork, unsigned long caller_ip);
 143 #define XFS_BMAP_TRACE_EXLIST(ip,c,w)   \
 144         xfs_bmap_trace_exlist(ip,c,w, _THIS_IP_)
 145 #else
 146 #define XFS_BMAP_TRACE_EXLIST(ip,c,w)
 147 #endif
 148
 149 int     xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
 150 void    xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
 151 void    xfs_bmap_add_free(xfs_fsblock_t bno, xfs_filblks_t len,
 152                 struct xfs_bmap_free *flist, struct xfs_mount *mp);
 153 void    xfs_bmap_cancel(struct xfs_bmap_free *flist);
 154 void    xfs_bmap_compute_maxlevels(struct xfs_mount *mp, int whichfork);
 155 int     xfs_bmap_first_unused(struct xfs_trans *tp, struct xfs_inode *ip,
 156                 xfs_extlen_t len, xfs_fileoff_t *unused, int whichfork);
 157 int     xfs_bmap_last_before(struct xfs_trans *tp, struct xfs_inode *ip,
 158                 xfs_fileoff_t *last_block, int whichfork);
 159 int     xfs_bmap_last_offset(struct xfs_inode *ip, xfs_fileoff_t *unused,
 160                 int whichfork);
 161 int     xfs_bmap_one_block(struct xfs_inode *ip, int whichfork);
 162 int     xfs_bmap_read_extents(struct xfs_trans *tp, struct xfs_inode *ip,
 163                 int whichfork);
 164 int     xfs_bmapi_read(struct xfs_inode *ip, xfs_fileoff_t bno,
 165                 xfs_filblks_t len, struct xfs_bmbt_irec *mval,
 166                 int *nmap, int flags);
 167 int     xfs_bmapi_delay(struct xfs_inode *ip, xfs_fileoff_t bno,
 168                 xfs_filblks_t len, struct xfs_bmbt_irec *mval,
 169                 int *nmap, int flags);
 170 int     xfs_bmapi_write(struct xfs_trans *tp, struct xfs_inode *ip,
 171                 xfs_fileoff_t bno, xfs_filblks_t len, int flags,
 172                 xfs_fsblock_t *firstblock, xfs_extlen_t total,
 173                 struct xfs_bmbt_irec *mval, int *nmap,
 174                 struct xfs_bmap_free *flist);
 175 int     xfs_bunmapi(struct xfs_trans *tp, struct xfs_inode *ip,
 176                 xfs_fileoff_t bno, xfs_filblks_t len, int flags,
 177                 xfs_extnum_t nexts, xfs_fsblock_t *firstblock,
 178                 struct xfs_bmap_free *flist, int *done);
 179 int     xfs_check_nostate_extents(struct xfs_ifork *ifp, xfs_extnum_t idx,
 180                 xfs_extnum_t num);
 181 uint    xfs_default_attroffset(struct xfs_inode *ip);
 182 int     xfs_bmap_shift_extents(struct xfs_trans *tp, struct xfs_inode *ip,
 183                 int *done, xfs_fileoff_t start_fsb,
 184                 xfs_fileoff_t offset_shift_fsb, xfs_extnum_t *current_ext,
 185                 xfs_fsblock_t *firstblock, struct xfs_bmap_free *flist,
 186                 int num_exts);
 187
 188 #endif  /* __XFS_BMAP_H__ */