LXR linux/fs/xfs/xfs_buf

   1/*
   2 * Copyright (c) 2000-2001,2005 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_BUF_ITEM_H__
  19#define __XFS_BUF_ITEM_H__
  20
  21extern kmem_zone_t      *xfs_buf_item_zone;
  22
  23/*
  24 * This flag indicates that the buffer contains on disk inodes
  25 * and requires special recovery handling.
  26 */
  27#define XFS_BLF_INODE_BUF       (1<<0)
  28/*
  29 * This flag indicates that the buffer should not be replayed
  30 * during recovery because its blocks are being freed.
  31 */
  32#define XFS_BLF_CANCEL          (1<<1)
  33
  34/*
  35 * This flag indicates that the buffer contains on disk
  36 * user or group dquots and may require special recovery handling.
  37 */
  38#define XFS_BLF_UDQUOT_BUF      (1<<2)
  39#define XFS_BLF_PDQUOT_BUF      (1<<3)
  40#define XFS_BLF_GDQUOT_BUF      (1<<4)
  41
  42#define XFS_BLF_CHUNK           128
  43#define XFS_BLF_SHIFT           7
  44#define BIT_TO_WORD_SHIFT       5
  45#define NBWORD                  (NBBY * sizeof(unsigned int))
  46
  47/*
  48 * This is the structure used to lay out a buf log item in the
  49 * log.  The data map describes which 128 byte chunks of the buffer
  50 * have been logged.
  51 */
  52#define XFS_BLF_DATAMAP_SIZE    ((XFS_MAX_BLOCKSIZE / XFS_BLF_CHUNK) / NBWORD)
  53
  54typedef struct xfs_buf_log_format {
  55        unsigned short  blf_type;       /* buf log item type indicator */
  56        unsigned short  blf_size;       /* size of this item */
  57        ushort          blf_flags;      /* misc state */
  58        ushort          blf_len;        /* number of blocks in this buf */
  59        __int64_t       blf_blkno;      /* starting blkno of this buf */
  60        unsigned int    blf_map_size;   /* used size of data bitmap in words */
  61        unsigned int    blf_data_map[XFS_BLF_DATAMAP_SIZE]; /* dirty bitmap */
  62} xfs_buf_log_format_t;
  63
  64/*
  65 * All buffers now need to tell recovery where the magic number
  66 * is so that it can verify and calculate the CRCs on the buffer correctly
  67 * once the changes have been replayed into the buffer.
  68 *
  69 * The type value is held in the upper 5 bits of the blf_flags field, which is
  70 * an unsigned 16 bit field. Hence we need to shift it 11 bits up and down.
  71 */
  72#define XFS_BLFT_BITS   5
  73#define XFS_BLFT_SHIFT  11
  74#define XFS_BLFT_MASK   (((1 << XFS_BLFT_BITS) - 1) << XFS_BLFT_SHIFT)
  75
  76enum xfs_blft {
  77        XFS_BLFT_UNKNOWN_BUF = 0,
  78        XFS_BLFT_UDQUOT_BUF,
  79        XFS_BLFT_PDQUOT_BUF,
  80        XFS_BLFT_GDQUOT_BUF,
  81        XFS_BLFT_BTREE_BUF,
  82        XFS_BLFT_AGF_BUF,
  83        XFS_BLFT_AGFL_BUF,
  84        XFS_BLFT_AGI_BUF,
  85        XFS_BLFT_DINO_BUF,
  86        XFS_BLFT_SYMLINK_BUF,
  87        XFS_BLFT_DIR_BLOCK_BUF,
  88        XFS_BLFT_DIR_DATA_BUF,
  89        XFS_BLFT_DIR_FREE_BUF,
  90        XFS_BLFT_DIR_LEAF1_BUF,
  91        XFS_BLFT_DIR_LEAFN_BUF,
  92        XFS_BLFT_DA_NODE_BUF,
  93        XFS_BLFT_ATTR_LEAF_BUF,
  94        XFS_BLFT_ATTR_RMT_BUF,
  95        XFS_BLFT_SB_BUF,
  96        XFS_BLFT_MAX_BUF = (1 << XFS_BLFT_BITS),
  97};
  98
  99static inline void
 100xfs_blft_to_flags(struct xfs_buf_log_format *blf, enum xfs_blft type)
 101{
 102        ASSERT(type > XFS_BLFT_UNKNOWN_BUF && type < XFS_BLFT_MAX_BUF);
 103        blf->blf_flags &= ~XFS_BLFT_MASK;
 104        blf->blf_flags |= ((type << XFS_BLFT_SHIFT) & XFS_BLFT_MASK);
 105}
 106
 107static inline __uint16_t
 108xfs_blft_from_flags(struct xfs_buf_log_format *blf)
 109{
 110        return (blf->blf_flags & XFS_BLFT_MASK) >> XFS_BLFT_SHIFT;
 111}
 112
 113/*
 114 * buf log item flags
 115 */
 116#define XFS_BLI_HOLD            0x01
 117#define XFS_BLI_DIRTY           0x02
 118#define XFS_BLI_STALE           0x04
 119#define XFS_BLI_LOGGED          0x08
 120#define XFS_BLI_INODE_ALLOC_BUF 0x10
 121#define XFS_BLI_STALE_INODE     0x20
 122#define XFS_BLI_INODE_BUF       0x40
 123
 124#define XFS_BLI_FLAGS \
 125        { XFS_BLI_HOLD,         "HOLD" }, \
 126        { XFS_BLI_DIRTY,        "DIRTY" }, \
 127        { XFS_BLI_STALE,        "STALE" }, \
 128        { XFS_BLI_LOGGED,       "LOGGED" }, \
 129        { XFS_BLI_INODE_ALLOC_BUF, "INODE_ALLOC" }, \
 130        { XFS_BLI_STALE_INODE,  "STALE_INODE" }, \
 131        { XFS_BLI_INODE_BUF,    "INODE_BUF" }
 132
 133
 134#ifdef __KERNEL__
 135
 136struct xfs_buf;
 137struct xfs_mount;
 138struct xfs_buf_log_item;
 139
 140/*
 141 * This is the in core log item structure used to track information
 142 * needed to log buffers.  It tracks how many times the lock has been
 143 * locked, and which 128 byte chunks of the buffer are dirty.
 144 */
 145typedef struct xfs_buf_log_item {
 146        xfs_log_item_t          bli_item;       /* common item structure */
 147        struct xfs_buf          *bli_buf;       /* real buffer pointer */
 148        unsigned int            bli_flags;      /* misc flags */
 149        unsigned int            bli_recur;      /* lock recursion count */
 150        atomic_t                bli_refcount;   /* cnt of tp refs */
 151        int                     bli_format_count;       /* count of headers */
 152        struct xfs_buf_log_format *bli_formats; /* array of in-log header ptrs */
 153        struct xfs_buf_log_format __bli_format; /* embedded in-log header */
 154} xfs_buf_log_item_t;
 155
 156void    xfs_buf_item_init(struct xfs_buf *, struct xfs_mount *);
 157void    xfs_buf_item_relse(struct xfs_buf *);
 158void    xfs_buf_item_log(xfs_buf_log_item_t *, uint, uint);
 159uint    xfs_buf_item_dirty(xfs_buf_log_item_t *);
 160void    xfs_buf_attach_iodone(struct xfs_buf *,
 161                              void(*)(struct xfs_buf *, xfs_log_item_t *),
 162                              xfs_log_item_t *);
 163void    xfs_buf_iodone_callbacks(struct xfs_buf *);
 164void    xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *);
 165
 166void    xfs_trans_buf_set_type(struct xfs_trans *, struct xfs_buf *,
 167                               enum xfs_blft);
 168void    xfs_trans_buf_copy_type(struct xfs_buf *dst_bp, struct xfs_buf *src_bp);
 169
 170#endif  /* __KERNEL__ */
 171
 172#endif  /* __XFS_BUF_ITEM_H__ */
 173