release/src-rt-6.x/linux/linux-2.6/fs/xfs/xfs_ialloc.h

   1 /*
   2  * Copyright (c) 2000,2005 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_IALLOC_H__
  19 #define __XFS_IALLOC_H__
  20
  21 struct xfs_buf;
  22 struct xfs_dinode;
  23 struct xfs_mount;
  24 struct xfs_trans;
  25
  26 /*
  27  * Allocation parameters for inode allocation.
  28  */
  29 #define XFS_IALLOC_INODES(mp)   (mp)->m_ialloc_inos
  30 #define XFS_IALLOC_BLOCKS(mp)   (mp)->m_ialloc_blks
  31
  32 /*
  33  * For small block file systems, move inodes in clusters of this size.
  34  * When we don't have a lot of memory, however, we go a bit smaller
  35  * to reduce the number of AGI and ialloc btree blocks we need to keep
  36  * around for xfs_dilocate().  We choose which one to use in
  37  * xfs_mount_int().
  38  */
  39 #define XFS_INODE_BIG_CLUSTER_SIZE      8192
  40 #define XFS_INODE_SMALL_CLUSTER_SIZE    4096
  41 #define XFS_INODE_CLUSTER_SIZE(mp)      (mp)->m_inode_cluster_size
  42
  43 /*
  44  * Make an inode pointer out of the buffer/offset.
  45  */
  46 #define XFS_MAKE_IPTR(mp,b,o)           xfs_make_iptr(mp,b,o)
  47 static inline struct xfs_dinode *
  48 xfs_make_iptr(struct xfs_mount *mp, struct xfs_buf *b, int o)
  49 {
  50         return (xfs_dinode_t *)
  51                 (xfs_buf_offset(b, o << (mp)->m_sb.sb_inodelog));
  52 }
  53
  54 /*
  55  * Find a free (set) bit in the inode bitmask.
  56  */
  57 #define XFS_IALLOC_FIND_FREE(fp)        xfs_ialloc_find_free(fp)
  58 static inline int xfs_ialloc_find_free(xfs_inofree_t *fp)
  59 {
  60         return xfs_lowbit64(*fp);
  61 }
  62
  63
  64 #ifdef __KERNEL__
  65 /*
  66  * Allocate an inode on disk.
  67  * Mode is used to tell whether the new inode will need space, and whether
  68  * it is a directory.
  69  *
  70  * To work within the constraint of one allocation per transaction,
  71  * xfs_dialloc() is designed to be called twice if it has to do an
  72  * allocation to make more free inodes.  If an inode is
  73  * available without an allocation, agbp would be set to the current
  74  * agbp and alloc_done set to false.
  75  * If an allocation needed to be done, agbp would be set to the
  76  * inode header of the allocation group and alloc_done set to true.
  77  * The caller should then commit the current transaction and allocate a new
  78  * transaction.  xfs_dialloc() should then be called again with
  79  * the agbp value returned from the previous call.
  80  *
  81  * Once we successfully pick an inode its number is returned and the
  82  * on-disk data structures are updated.  The inode itself is not read
  83  * in, since doing so would break ordering constraints with xfs_reclaim.
  84  *
  85  * *agbp should be set to NULL on the first call, *alloc_done set to FALSE.
  86  */
  87 int                                     /* error */
  88 xfs_dialloc(
  89         struct xfs_trans *tp,           /* transaction pointer */
  90         xfs_ino_t       parent,         /* parent inode (directory) */
  91         mode_t          mode,           /* mode bits for new inode */
  92         int             okalloc,        /* ok to allocate more space */
  93         struct xfs_buf  **agbp,         /* buf for a.g. inode header */
  94         boolean_t       *alloc_done,    /* an allocation was done to replenish
  95                                            the free inodes */
  96         xfs_ino_t       *inop);         /* inode number allocated */
  97
  98 /*
  99  * Free disk inode.  Carefully avoids touching the incore inode, all
 100  * manipulations incore are the caller's responsibility.
 101  * The on-disk inode is not changed by this operation, only the
 102  * btree (free inode mask) is changed.
 103  */
 104 int                                     /* error */
 105 xfs_difree(
 106         struct xfs_trans *tp,           /* transaction pointer */
 107         xfs_ino_t       inode,          /* inode to be freed */
 108         struct xfs_bmap_free *flist,    /* extents to free */
 109         int             *delete,        /* set if inode cluster was deleted */
 110         xfs_ino_t       *first_ino);    /* first inode in deleted cluster */
 111
 112 /*
 113  * Return the location of the inode in bno/len/off,
 114  * for mapping it into a buffer.
 115  */
 116 int
 117 xfs_dilocate(
 118         struct xfs_mount *mp,           /* file system mount structure */
 119         struct xfs_trans *tp,           /* transaction pointer */
 120         xfs_ino_t       ino,            /* inode to locate */
 121         xfs_fsblock_t   *bno,           /* output: block containing inode */
 122         int             *len,           /* output: num blocks in cluster*/
 123         int             *off,           /* output: index in block of inode */
 124         uint            flags);         /* flags for inode btree lookup */
 125
 126 /*
 127  * Compute and fill in value of m_in_maxlevels.
 128  */
 129 void
 130 xfs_ialloc_compute_maxlevels(
 131         struct xfs_mount *mp);          /* file system mount structure */
 132
 133 /*
 134  * Log specified fields for the ag hdr (inode section)
 135  */
 136 void
 137 xfs_ialloc_log_agi(
 138         struct xfs_trans *tp,           /* transaction pointer */
 139         struct xfs_buf  *bp,            /* allocation group header buffer */
 140         int             fields);        /* bitmask of fields to log */
 141
 142 /*
 143  * Read in the allocation group header (inode allocation section)
 144  */
 145 int                                     /* error */
 146 xfs_ialloc_read_agi(
 147         struct xfs_mount *mp,           /* file system mount structure */
 148         struct xfs_trans *tp,           /* transaction pointer */
 149         xfs_agnumber_t  agno,           /* allocation group number */
 150         struct xfs_buf  **bpp);         /* allocation group hdr buf */
 151
 152 #endif  /* __KERNEL__ */
 153
 154 #endif  /* __XFS_IALLOC_H__ */