LXR linux/fs/xfs/libxfs/xfs

   1/*
   2 * Copyright (C) 2016 Oracle.  All Rights Reserved.
   3 *
   4 * Author: Darrick J. Wong <darrick.wong@oracle.com>
   5 *
   6 * This program is free software; you can redistribute it and/or
   7 * modify it under the terms of the GNU General Public License
   8 * as published by the Free Software Foundation; either version 2
   9 * of the License, or (at your option) any later version.
  10 *
  11 * This program is distributed in the hope that it would be useful,
  12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 * GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program; if not, write the Free Software Foundation,
  18 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
  19 */
  20#ifndef __XFS_DEFER_H__
  21#define __XFS_DEFER_H__
  22
  23struct xfs_defer_op_type;
  24
  25/*
  26 * Save a log intent item and a list of extents, so that we can replay
  27 * whatever action had to happen to the extent list and file the log done
  28 * item.
  29 */
  30struct xfs_defer_pending {
  31        const struct xfs_defer_op_type  *dfp_type;      /* function pointers */
  32        struct list_head                dfp_list;       /* pending items */
  33        void                            *dfp_intent;    /* log intent item */
  34        void                            *dfp_done;      /* log done item */
  35        struct list_head                dfp_work;       /* work items */
  36        unsigned int                    dfp_count;      /* # extent items */
  37};
  38
  39/*
  40 * Header for deferred operation list.
  41 *
  42 * dop_low is used by the allocator to activate the lowspace algorithm -
  43 * when free space is running low the extent allocator may choose to
  44 * allocate an extent from an AG without leaving sufficient space for
  45 * a btree split when inserting the new extent.  In this case the allocator
  46 * will enable the lowspace algorithm which is supposed to allow further
  47 * allocations (such as btree splits and newroots) to allocate from
  48 * sequential AGs.  In order to avoid locking AGs out of order the lowspace
  49 * algorithm will start searching for free space from AG 0.  If the correct
  50 * transaction reservations have been made then this algorithm will eventually
  51 * find all the space it needs.
  52 */
  53enum xfs_defer_ops_type {
  54        XFS_DEFER_OPS_TYPE_BMAP,
  55        XFS_DEFER_OPS_TYPE_REFCOUNT,
  56        XFS_DEFER_OPS_TYPE_RMAP,
  57        XFS_DEFER_OPS_TYPE_FREE,
  58        XFS_DEFER_OPS_TYPE_MAX,
  59};
  60
  61#define XFS_DEFER_OPS_NR_INODES 2       /* join up to two inodes */
  62#define XFS_DEFER_OPS_NR_BUFS   2       /* join up to two buffers */
  63
  64struct xfs_defer_ops {
  65        bool                    dop_committed;  /* did any trans commit? */
  66        bool                    dop_low;        /* alloc in low mode */
  67        struct list_head        dop_intake;     /* unlogged pending work */
  68        struct list_head        dop_pending;    /* logged pending work */
  69
  70        /* relog these with each roll */
  71        struct xfs_inode        *dop_inodes[XFS_DEFER_OPS_NR_INODES];
  72        struct xfs_buf          *dop_bufs[XFS_DEFER_OPS_NR_BUFS];
  73};
  74
  75void xfs_defer_add(struct xfs_defer_ops *dop, enum xfs_defer_ops_type type,
  76                struct list_head *h);
  77int xfs_defer_finish(struct xfs_trans **tp, struct xfs_defer_ops *dop);
  78void xfs_defer_cancel(struct xfs_defer_ops *dop);
  79void xfs_defer_init(struct xfs_defer_ops *dop, xfs_fsblock_t *fbp);
  80bool xfs_defer_has_unfinished_work(struct xfs_defer_ops *dop);
  81int xfs_defer_ijoin(struct xfs_defer_ops *dop, struct xfs_inode *ip);
  82int xfs_defer_bjoin(struct xfs_defer_ops *dop, struct xfs_buf *bp);
  83
  84/* Description of a deferred type. */
  85struct xfs_defer_op_type {
  86        enum xfs_defer_ops_type type;
  87        unsigned int            max_items;
  88        void (*abort_intent)(void *);
  89        void *(*create_done)(struct xfs_trans *, void *, unsigned int);
  90        int (*finish_item)(struct xfs_trans *, struct xfs_defer_ops *,
  91                        struct list_head *, void *, void **);
  92        void (*finish_cleanup)(struct xfs_trans *, void *, int);
  93        void (*cancel_item)(struct list_head *);
  94        int (*diff_items)(void *, struct list_head *, struct list_head *);
  95        void *(*create_intent)(struct xfs_trans *, uint);
  96        void (*log_item)(struct xfs_trans *, void *, struct list_head *);
  97};
  98
  99void xfs_defer_init_op_type(const struct xfs_defer_op_type *type);
 100
 101#endif /* __XFS_DEFER_H__ */
 102