/*
 * Copyright (C) 2016 Oracle.  All Rights Reserved.
 *
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_rmap_item.h"
#include "xfs_alloc.h"
#include "xfs_rmap.h"

/* Set the map extent flags for this reverse mapping. */
static void
xfs_trans_set_rmap_flags(
        struct xfs_map_extent           *rmap,
        enum xfs_rmap_intent_type       type,
        int                             whichfork,
        xfs_exntst_t                    state)
{
        rmap->me_flags = 0;
        if (state == XFS_EXT_UNWRITTEN)
                rmap->me_flags |= XFS_RMAP_EXTENT_UNWRITTEN;
        if (whichfork == XFS_ATTR_FORK)
                rmap->me_flags |= XFS_RMAP_EXTENT_ATTR_FORK;
        switch (type) {
        case XFS_RMAP_MAP:
                rmap->me_flags |= XFS_RMAP_EXTENT_MAP;
                break;
        case XFS_RMAP_MAP_SHARED:
                rmap->me_flags |= XFS_RMAP_EXTENT_MAP_SHARED;
                break;
        case XFS_RMAP_UNMAP:
                rmap->me_flags |= XFS_RMAP_EXTENT_UNMAP;
                break;
        case XFS_RMAP_UNMAP_SHARED:
                rmap->me_flags |= XFS_RMAP_EXTENT_UNMAP_SHARED;
                break;
        case XFS_RMAP_CONVERT:
                rmap->me_flags |= XFS_RMAP_EXTENT_CONVERT;
                break;
        case XFS_RMAP_CONVERT_SHARED:
                rmap->me_flags |= XFS_RMAP_EXTENT_CONVERT_SHARED;
                break;
        case XFS_RMAP_ALLOC:
                rmap->me_flags |= XFS_RMAP_EXTENT_ALLOC;
                break;
        case XFS_RMAP_FREE:
                rmap->me_flags |= XFS_RMAP_EXTENT_FREE;
                break;
        default:
                ASSERT(0);
        }
}

struct xfs_rud_log_item *
xfs_trans_get_rud(
        struct xfs_trans                *tp,
        struct xfs_rui_log_item         *ruip)
{
        struct xfs_rud_log_item         *rudp;

        rudp = xfs_rud_init(tp->t_mountp, ruip);
        xfs_trans_add_item(tp, &rudp->rud_item);
        return rudp;
}

/*
 * Finish an rmap update and log it to the RUD. Note that the transaction is
 * marked dirty regardless of whether the rmap update succeeds or fails to
 * support the RUI/RUD lifecycle rules.
 */
int
xfs_trans_log_finish_rmap_update(
        struct xfs_trans                *tp,
        struct xfs_rud_log_item         *rudp,
        enum xfs_rmap_intent_type       type,
        __uint64_t                      owner,
        int                             whichfork,
        xfs_fileoff_t                   startoff,
        xfs_fsblock_t                   startblock,
        xfs_filblks_t                   blockcount,
        xfs_exntst_t                    state,
        struct xfs_btree_cur            **pcur)
{
        int                             error;

        error = xfs_rmap_finish_one(tp, type, owner, whichfork, startoff,
                        startblock, blockcount, state, pcur);

        /*
         * Mark the transaction dirty, even on error. This ensures the
         * transaction is aborted, which:
         *
         * 1.) releases the RUI and frees the RUD
         * 2.) shuts down the filesystem
         */
        tp->t_flags |= XFS_TRANS_DIRTY;
        rudp->rud_item.li_desc->lid_flags |= XFS_LID_DIRTY;

        return error;
}

/* Sort rmap intents by AG. */
static int
xfs_rmap_update_diff_items(
        void                            *priv,
        struct list_head                *a,
        struct list_head                *b)
{
        struct xfs_mount                *mp = priv;
        struct xfs_rmap_intent          *ra;
        struct xfs_rmap_intent          *rb;

        ra = container_of(a, struct xfs_rmap_intent, ri_list);
        rb = container_of(b, struct xfs_rmap_intent, ri_list);
        return  XFS_FSB_TO_AGNO(mp, ra->ri_bmap.br_startblock) -
                XFS_FSB_TO_AGNO(mp, rb->ri_bmap.br_startblock);
}

/* Get an RUI. */
STATIC void *
xfs_rmap_update_create_intent(
        struct xfs_trans                *tp,
        unsigned int                    count)
{
        struct xfs_rui_log_item         *ruip;

        ASSERT(tp != NULL);
        ASSERT(count > 0);

        ruip = xfs_rui_init(tp->t_mountp, count);
        ASSERT(ruip != NULL);

        /*
         * Get a log_item_desc to point at the new item.
         */
        xfs_trans_add_item(tp, &ruip->rui_item);
        return ruip;
}

/* Log rmap updates in the intent item. */
STATIC void
xfs_rmap_update_log_item(
        struct xfs_trans                *tp,
        void                            *intent,
        struct list_head                *item)
{
        struct xfs_rui_log_item         *ruip = intent;
        struct xfs_rmap_intent          *rmap;
        uint                            next_extent;
        struct xfs_map_extent           *map;

        rmap = container_of(item, struct xfs_rmap_intent, ri_list);

        tp->t_flags |= XFS_TRANS_DIRTY;
        ruip->rui_item.li_desc->lid_flags |= XFS_LID_DIRTY;

        /*
         * atomic_inc_return gives us the value after the increment;
         * we want to use it as an array index so we need to subtract 1 from
         * it.
         */
        next_extent = atomic_inc_return(&ruip->rui_next_extent) - 1;
        ASSERT(next_extent < ruip->rui_format.rui_nextents);
        map = &ruip->rui_format.rui_extents[next_extent];
        map->me_owner = rmap->ri_owner;
        map->me_startblock = rmap->ri_bmap.br_startblock;
        map->me_startoff = rmap->ri_bmap.br_startoff;
        map->me_len = rmap->ri_bmap.br_blockcount;
        xfs_trans_set_rmap_flags(map, rmap->ri_type, rmap->ri_whichfork,
                        rmap->ri_bmap.br_state);
}

/* Get an RUD so we can process all the deferred rmap updates. */
STATIC void *
xfs_rmap_update_create_done(
        struct xfs_trans                *tp,
        void                            *intent,
        unsigned int                    count)
{
        return xfs_trans_get_rud(tp, intent);
}

/* Process a deferred rmap update. */
STATIC int
xfs_rmap_update_finish_item(
        struct xfs_trans                *tp,
        struct xfs_defer_ops            *dop,
        struct list_head                *item,
        void                            *done_item,
        void                            **state)
{
        struct xfs_rmap_intent          *rmap;
        int                             error;

        rmap = container_of(item, struct xfs_rmap_intent, ri_list);
        error = xfs_trans_log_finish_rmap_update(tp, done_item,
                        rmap->ri_type,
                        rmap->ri_owner, rmap->ri_whichfork,
                        rmap->ri_bmap.br_startoff,
                        rmap->ri_bmap.br_startblock,
                        rmap->ri_bmap.br_blockcount,
                        rmap->ri_bmap.br_state,
                        (struct xfs_btree_cur **)state);
        kmem_free(rmap);
        return error;
}

/* Clean up after processing deferred rmaps. */
STATIC void
xfs_rmap_update_finish_cleanup(
        struct xfs_trans        *tp,
        void                    *state,
        int                     error)
{
        struct xfs_btree_cur    *rcur = state;

        xfs_rmap_finish_one_cleanup(tp, rcur, error);
}

/* Abort all pending RUIs. */
STATIC void
xfs_rmap_update_abort_intent(
        void                            *intent)
{
        xfs_rui_release(intent);
}

/* Cancel a deferred rmap update. */
STATIC void
xfs_rmap_update_cancel_item(
        struct list_head                *item)
{
        struct xfs_rmap_intent          *rmap;

        rmap = container_of(item, struct xfs_rmap_intent, ri_list);
        kmem_free(rmap);
}

static const struct xfs_defer_op_type xfs_rmap_update_defer_type = {
        .type           = XFS_DEFER_OPS_TYPE_RMAP,
        .max_items      = XFS_RUI_MAX_FAST_EXTENTS,
        .diff_items     = xfs_rmap_update_diff_items,
        .create_intent  = xfs_rmap_update_create_intent,
        .abort_intent   = xfs_rmap_update_abort_intent,
        .log_item       = xfs_rmap_update_log_item,
        .create_done    = xfs_rmap_update_create_done,
        .finish_item    = xfs_rmap_update_finish_item,
        .finish_cleanup = xfs_rmap_update_finish_cleanup,
        .cancel_item    = xfs_rmap_update_cancel_item,
};

/* Register the deferred op type. */
void
xfs_rmap_update_init_defer_op(void)
{
        xfs_defer_init_op_type(&xfs_rmap_update_defer_type);
}