libxfs/xfs_defer.h

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2016 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   5  */
   6 #ifndef __XFS_DEFER_H__
   7 #define __XFS_DEFER_H__
   8
   9 struct xfs_defer_op_type;
  10 struct xfs_defer_ops;
  11
  12 /*
  13  * Save a log intent item and a list of extents, so that we can replay
  14  * whatever action had to happen to the extent list and file the log done
  15  * item.
  16  */
  17 struct xfs_defer_pending {
  18         const struct xfs_defer_op_type  *dfp_type;      /* function pointers */
  19         struct list_head                dfp_list;       /* pending items */
  20         void                            *dfp_intent;    /* log intent item */
  21         void                            *dfp_done;      /* log done item */
  22         struct list_head                dfp_work;       /* work items */
  23         unsigned int                    dfp_count;      /* # extent items */
  24 };
  25
  26 /*
  27  * Header for deferred operation list.
  28  *
  29  * dop_low is used by the allocator to activate the lowspace algorithm -
  30  * when free space is running low the extent allocator may choose to
  31  * allocate an extent from an AG without leaving sufficient space for
  32  * a btree split when inserting the new extent.  In this case the allocator
  33  * will enable the lowspace algorithm which is supposed to allow further
  34  * allocations (such as btree splits and newroots) to allocate from
  35  * sequential AGs.  In order to avoid locking AGs out of order the lowspace
  36  * algorithm will start searching for free space from AG 0.  If the correct
  37  * transaction reservations have been made then this algorithm will eventually
  38  * find all the space it needs.
  39  */
  40 enum xfs_defer_ops_type {
  41         XFS_DEFER_OPS_TYPE_BMAP,
  42         XFS_DEFER_OPS_TYPE_REFCOUNT,
  43         XFS_DEFER_OPS_TYPE_RMAP,
  44         XFS_DEFER_OPS_TYPE_FREE,
  45         XFS_DEFER_OPS_TYPE_AGFL_FREE,
  46         XFS_DEFER_OPS_TYPE_MAX,
  47 };
  48
  49 void xfs_defer_add(struct xfs_defer_ops *dop, enum xfs_defer_ops_type type,
  50                 struct list_head *h);
  51 int xfs_defer_finish_noroll(struct xfs_trans **tp);
  52 int xfs_defer_finish(struct xfs_trans **tp);
  53 void __xfs_defer_cancel(struct xfs_defer_ops *dop);
  54 void xfs_defer_init(struct xfs_trans *tp, struct xfs_defer_ops *dop);
  55 bool xfs_defer_has_unfinished_work(struct xfs_defer_ops *dop);
  56 int xfs_defer_ijoin(struct xfs_defer_ops *dop, struct xfs_inode *ip);
  57 int xfs_defer_bjoin(struct xfs_defer_ops *dop, struct xfs_buf *bp);
  58 void xfs_defer_move(struct xfs_defer_ops *dst, struct xfs_defer_ops *src);
  59
  60 /* Description of a deferred type. */
  61 struct xfs_defer_op_type {
  62         enum xfs_defer_ops_type type;
  63         unsigned int            max_items;
  64         void (*abort_intent)(void *);
  65         void *(*create_done)(struct xfs_trans *, void *, unsigned int);
  66         int (*finish_item)(struct xfs_trans *, struct xfs_defer_ops *,
  67                         struct list_head *, void *, void **);
  68         void (*finish_cleanup)(struct xfs_trans *, void *, int);
  69         void (*cancel_item)(struct list_head *);
  70         int (*diff_items)(void *, struct list_head *, struct list_head *);
  71         void *(*create_intent)(struct xfs_trans *, uint);
  72         void (*log_item)(struct xfs_trans *, void *, struct list_head *);
  73 };
  74
  75 void xfs_defer_init_op_type(const struct xfs_defer_op_type *type);
  76
  77 #endif /* __XFS_DEFER_H__ */