release/src-rt-6.x.4708/linux/linux-2.6.36/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_imap;
  24 struct xfs_mount;
  25 struct xfs_trans;
  26
  27 /*
  28  * Allocation parameters for inode allocation.
  29  */
  30 #define XFS_IALLOC_INODES(mp)   (mp)->m_ialloc_inos
  31 #define XFS_IALLOC_BLOCKS(mp)   (mp)->m_ialloc_blks
  32
  33 /*
  34  * Move inodes in clusters of this size.
  35  */
  36 #define XFS_INODE_BIG_CLUSTER_SIZE      8192
  37 #define XFS_INODE_CLUSTER_SIZE(mp)      (mp)->m_inode_cluster_size
  38
  39 /*
  40  * Make an inode pointer out of the buffer/offset.
  41  */
  42 static inline struct xfs_dinode *
  43 xfs_make_iptr(struct xfs_mount *mp, struct xfs_buf *b, int o)
  44 {
  45         return (xfs_dinode_t *)
  46                 (xfs_buf_offset(b, o << (mp)->m_sb.sb_inodelog));
  47 }
  48
  49 /*
  50  * Find a free (set) bit in the inode bitmask.
  51  */
  52 static inline int xfs_ialloc_find_free(xfs_inofree_t *fp)
  53 {
  54         return xfs_lowbit64(*fp);
  55 }
  56
  57
  58 /*
  59  * Allocate an inode on disk.
  60  * Mode is used to tell whether the new inode will need space, and whether
  61  * it is a directory.
  62  *
  63  * To work within the constraint of one allocation per transaction,
  64  * xfs_dialloc() is designed to be called twice if it has to do an
  65  * allocation to make more free inodes.  If an inode is
  66  * available without an allocation, agbp would be set to the current
  67  * agbp and alloc_done set to false.
  68  * If an allocation needed to be done, agbp would be set to the
  69  * inode header of the allocation group and alloc_done set to true.
  70  * The caller should then commit the current transaction and allocate a new
  71  * transaction.  xfs_dialloc() should then be called again with
  72  * the agbp value returned from the previous call.
  73  *
  74  * Once we successfully pick an inode its number is returned and the
  75  * on-disk data structures are updated.  The inode itself is not read
  76  * in, since doing so would break ordering constraints with xfs_reclaim.
  77  *
  78  * *agbp should be set to NULL on the first call, *alloc_done set to FALSE.
  79  */
  80 int                                     /* error */
  81 xfs_dialloc(
  82         struct xfs_trans *tp,           /* transaction pointer */
  83         xfs_ino_t       parent,         /* parent inode (directory) */
  84         mode_t          mode,           /* mode bits for new inode */
  85         int             okalloc,        /* ok to allocate more space */
  86         struct xfs_buf  **agbp,         /* buf for a.g. inode header */
  87         boolean_t       *alloc_done,    /* an allocation was done to replenish
  88                                            the free inodes */
  89         xfs_ino_t       *inop);         /* inode number allocated */
  90
  91 /*
  92  * Free disk inode.  Carefully avoids touching the incore inode, all
  93  * manipulations incore are the caller's responsibility.
  94  * The on-disk inode is not changed by this operation, only the
  95  * btree (free inode mask) is changed.
  96  */
  97 int                                     /* error */
  98 xfs_difree(
  99         struct xfs_trans *tp,           /* transaction pointer */
 100         xfs_ino_t       inode,          /* inode to be freed */
 101         struct xfs_bmap_free *flist,    /* extents to free */
 102         int             *delete,        /* set if inode cluster was deleted */
 103         xfs_ino_t       *first_ino);    /* first inode in deleted cluster */
 104
 105 /*
 106  * Return the location of the inode in imap, for mapping it into a buffer.
 107  */
 108 int
 109 xfs_imap(
 110         struct xfs_mount *mp,           /* file system mount structure */
 111         struct xfs_trans *tp,           /* transaction pointer */
 112         xfs_ino_t       ino,            /* inode to locate */
 113         struct xfs_imap *imap,          /* location map structure */
 114         uint            flags);         /* flags for inode btree lookup */
 115
 116 /*
 117  * Compute and fill in value of m_in_maxlevels.
 118  */
 119 void
 120 xfs_ialloc_compute_maxlevels(
 121         struct xfs_mount *mp);          /* file system mount structure */
 122
 123 /*
 124  * Log specified fields for the ag hdr (inode section)
 125  */
 126 void
 127 xfs_ialloc_log_agi(
 128         struct xfs_trans *tp,           /* transaction pointer */
 129         struct xfs_buf  *bp,            /* allocation group header buffer */
 130         int             fields);        /* bitmask of fields to log */
 131
 132 /*
 133  * Read in the allocation group header (inode allocation section)
 134  */
 135 int                                     /* error */
 136 xfs_ialloc_read_agi(
 137         struct xfs_mount *mp,           /* file system mount structure */
 138         struct xfs_trans *tp,           /* transaction pointer */
 139         xfs_agnumber_t  agno,           /* allocation group number */
 140         struct xfs_buf  **bpp);         /* allocation group hdr buf */
 141
 142 /*
 143  * Read in the allocation group header to initialise the per-ag data
 144  * in the mount structure
 145  */
 146 int
 147 xfs_ialloc_pagi_init(
 148         struct xfs_mount *mp,           /* file system mount structure */
 149         struct xfs_trans *tp,           /* transaction pointer */
 150         xfs_agnumber_t  agno);          /* allocation group number */
 151
 152 /*
 153  * Lookup a record by ino in the btree given by cur.
 154  */
 155 int xfs_inobt_lookup(struct xfs_btree_cur *cur, xfs_agino_t ino,
 156                 xfs_lookup_t dir, int *stat);
 157
 158 /*
 159  * Get the data from the pointed-to record.
 160  */
 161 extern int xfs_inobt_get_rec(struct xfs_btree_cur *cur,
 162                 xfs_inobt_rec_incore_t *rec, int *stat);
 163
 164 #endif  /* __XFS_IALLOC_H__ */