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
  11 /*
  12  * Save a log intent item and a list of extents, so that we can replay
  13  * whatever action had to happen to the extent list and file the log done
  14  * item.
  15  */
  16 struct xfs_defer_pending {
  17         const struct xfs_defer_op_type  *dfp_type;      /* function pointers */
  18         struct list_head                dfp_list;       /* pending items */
  19         void                            *dfp_intent;    /* log intent item */
  20         void                            *dfp_done;      /* log done item */
  21         struct list_head                dfp_work;       /* work items */
  22         unsigned int                    dfp_count;      /* # extent items */
  23 };
  24
  25 /*
  26  * Header for deferred operation list.
  27  *
  28  * dop_low is used by the allocator to activate the lowspace algorithm -
  29  * when free space is running low the extent allocator may choose to
  30  * allocate an extent from an AG without leaving sufficient space for
  31  * a btree split when inserting the new extent.  In this case the allocator
  32  * will enable the lowspace algorithm which is supposed to allow further
  33  * allocations (such as btree splits and newroots) to allocate from
  34  * sequential AGs.  In order to avoid locking AGs out of order the lowspace
  35  * algorithm will start searching for free space from AG 0.  If the correct
  36  * transaction reservations have been made then this algorithm will eventually
  37  * find all the space it needs.
  38  */
  39 enum xfs_defer_ops_type {
  40         XFS_DEFER_OPS_TYPE_BMAP,
  41         XFS_DEFER_OPS_TYPE_REFCOUNT,
  42         XFS_DEFER_OPS_TYPE_RMAP,
  43         XFS_DEFER_OPS_TYPE_FREE,
  44         XFS_DEFER_OPS_TYPE_AGFL_FREE,
  45         XFS_DEFER_OPS_TYPE_MAX,
  46 };
  47
  48 #define XFS_DEFER_OPS_NR_INODES 2       /* join up to two inodes */
  49 #define XFS_DEFER_OPS_NR_BUFS   2       /* join up to two buffers */
  50
  51 struct xfs_defer_ops {
  52         bool                    dop_committed;  /* did any trans commit? */
  53         bool                    dop_low;        /* alloc in low mode */
  54         struct list_head        dop_intake;     /* unlogged pending work */
  55         struct list_head        dop_pending;    /* logged pending work */
  56
  57         /* relog these with each roll */
  58         struct xfs_inode        *dop_inodes[XFS_DEFER_OPS_NR_INODES];
  59         struct xfs_buf          *dop_bufs[XFS_DEFER_OPS_NR_BUFS];
  60 };
  61
  62 void xfs_defer_add(struct xfs_defer_ops *dop, enum xfs_defer_ops_type type,
  63                 struct list_head *h);
  64 int xfs_defer_finish(struct xfs_trans **tp, struct xfs_defer_ops *dop);
  65 void xfs_defer_cancel(struct xfs_defer_ops *dop);
  66 void xfs_defer_init(struct xfs_defer_ops *dop, xfs_fsblock_t *fbp);
  67 bool xfs_defer_has_unfinished_work(struct xfs_defer_ops *dop);
  68 int xfs_defer_ijoin(struct xfs_defer_ops *dop, struct xfs_inode *ip);
  69 int xfs_defer_bjoin(struct xfs_defer_ops *dop, struct xfs_buf *bp);
  70
  71 /* Description of a deferred type. */
  72 struct xfs_defer_op_type {
  73         enum xfs_defer_ops_type type;
  74         unsigned int            max_items;
  75         void (*abort_intent)(void *);
  76         void *(*create_done)(struct xfs_trans *, void *, unsigned int);
  77         int (*finish_item)(struct xfs_trans *, struct xfs_defer_ops *,
  78                         struct list_head *, void *, void **);
  79         void (*finish_cleanup)(struct xfs_trans *, void *, int);
  80         void (*cancel_item)(struct list_head *);
  81         int (*diff_items)(void *, struct list_head *, struct list_head *);
  82         void *(*create_intent)(struct xfs_trans *, uint);
  83         void (*log_item)(struct xfs_trans *, void *, struct list_head *);
  84 };
  85
  86 void xfs_defer_init_op_type(const struct xfs_defer_op_type *type);
  87
  88 #endif /* __XFS_DEFER_H__ */