// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (C) 2016 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <darrick.wong@oracle.com>
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_shared.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_refcount_item.h"
#include "xfs_log.h"
#include "xfs_refcount.h"
#include "xfs_error.h"
#include "xfs_log_priv.h"
#include "xfs_log_recover.h"

kmem_zone_t     *xfs_cui_zone;
kmem_zone_t     *xfs_cud_zone;

static const struct xfs_item_ops xfs_cui_item_ops;

static inline struct xfs_cui_log_item *CUI_ITEM(struct xfs_log_item *lip)
{
        return container_of(lip, struct xfs_cui_log_item, cui_item);
}

STATIC void
xfs_cui_item_free(
        struct xfs_cui_log_item *cuip)
{
        if (cuip->cui_format.cui_nextents > XFS_CUI_MAX_FAST_EXTENTS)
                kmem_free(cuip);
        else
                kmem_cache_free(xfs_cui_zone, cuip);
}

/*
 * Freeing the CUI requires that we remove it from the AIL if it has already
 * been placed there. However, the CUI may not yet have been placed in the AIL
 * when called by xfs_cui_release() from CUD processing due to the ordering of
 * committed vs unpin operations in bulk insert operations. Hence the reference
 * count to ensure only the last caller frees the CUI.
 */
STATIC void
xfs_cui_release(
        struct xfs_cui_log_item *cuip)
{
        ASSERT(atomic_read(&cuip->cui_refcount) > 0);
        if (atomic_dec_and_test(&cuip->cui_refcount)) {
                xfs_trans_ail_delete(&cuip->cui_item, SHUTDOWN_LOG_IO_ERROR);
                xfs_cui_item_free(cuip);
        }
}


STATIC void
xfs_cui_item_size(
        struct xfs_log_item     *lip,
        int                     *nvecs,
        int                     *nbytes)
{
        struct xfs_cui_log_item *cuip = CUI_ITEM(lip);

        *nvecs += 1;
        *nbytes += xfs_cui_log_format_sizeof(cuip->cui_format.cui_nextents);
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given cui log item. We use only 1 iovec, and we point that
 * at the cui_log_format structure embedded in the cui item.
 * It is at this point that we assert that all of the extent
 * slots in the cui item have been filled.
 */
STATIC void
xfs_cui_item_format(
        struct xfs_log_item     *lip,
        struct xfs_log_vec      *lv)
{
        struct xfs_cui_log_item *cuip = CUI_ITEM(lip);
        struct xfs_log_iovec    *vecp = NULL;

        ASSERT(atomic_read(&cuip->cui_next_extent) ==
                        cuip->cui_format.cui_nextents);

        cuip->cui_format.cui_type = XFS_LI_CUI;
        cuip->cui_format.cui_size = 1;

        xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_CUI_FORMAT, &cuip->cui_format,
                        xfs_cui_log_format_sizeof(cuip->cui_format.cui_nextents));
}

/*
 * The unpin operation is the last place an CUI is manipulated in the log. It is
 * either inserted in the AIL or aborted in the event of a log I/O error. In
 * either case, the CUI transaction has been successfully committed to make it
 * this far. Therefore, we expect whoever committed the CUI to either construct
 * and commit the CUD or drop the CUD's reference in the event of error. Simply
 * drop the log's CUI reference now that the log is done with it.
 */
STATIC void
xfs_cui_item_unpin(
        struct xfs_log_item     *lip,
        int                     remove)
{
        struct xfs_cui_log_item *cuip = CUI_ITEM(lip);

        xfs_cui_release(cuip);
}

/*
 * The CUI has been either committed or aborted if the transaction has been
 * cancelled. If the transaction was cancelled, an CUD isn't going to be
 * constructed and thus we free the CUI here directly.
 */
STATIC void
xfs_cui_item_release(
        struct xfs_log_item     *lip)
{
        xfs_cui_release(CUI_ITEM(lip));
}

/*
 * Allocate and initialize an cui item with the given number of extents.
 */
STATIC struct xfs_cui_log_item *
xfs_cui_init(
        struct xfs_mount                *mp,
        uint                            nextents)

{
        struct xfs_cui_log_item         *cuip;

        ASSERT(nextents > 0);
        if (nextents > XFS_CUI_MAX_FAST_EXTENTS)
                cuip = kmem_zalloc(xfs_cui_log_item_sizeof(nextents),
                                0);
        else
                cuip = kmem_cache_zalloc(xfs_cui_zone,
                                         GFP_KERNEL | __GFP_NOFAIL);

        xfs_log_item_init(mp, &cuip->cui_item, XFS_LI_CUI, &xfs_cui_item_ops);
        cuip->cui_format.cui_nextents = nextents;
        cuip->cui_format.cui_id = (uintptr_t)(void *)cuip;
        atomic_set(&cuip->cui_next_extent, 0);
        atomic_set(&cuip->cui_refcount, 2);

        return cuip;
}

static inline struct xfs_cud_log_item *CUD_ITEM(struct xfs_log_item *lip)
{
        return container_of(lip, struct xfs_cud_log_item, cud_item);
}

STATIC void
xfs_cud_item_size(
        struct xfs_log_item     *lip,
        int                     *nvecs,
        int                     *nbytes)
{
        *nvecs += 1;
        *nbytes += sizeof(struct xfs_cud_log_format);
}

/*
 * This is called to fill in the vector of log iovecs for the
 * given cud log item. We use only 1 iovec, and we point that
 * at the cud_log_format structure embedded in the cud item.
 * It is at this point that we assert that all of the extent
 * slots in the cud item have been filled.
 */
STATIC void
xfs_cud_item_format(
        struct xfs_log_item     *lip,
        struct xfs_log_vec      *lv)
{
        struct xfs_cud_log_item *cudp = CUD_ITEM(lip);
        struct xfs_log_iovec    *vecp = NULL;

        cudp->cud_format.cud_type = XFS_LI_CUD;
        cudp->cud_format.cud_size = 1;

        xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_CUD_FORMAT, &cudp->cud_format,
                        sizeof(struct xfs_cud_log_format));
}

/*
 * The CUD is either committed or aborted if the transaction is cancelled. If
 * the transaction is cancelled, drop our reference to the CUI and free the
 * CUD.
 */
STATIC void
xfs_cud_item_release(
        struct xfs_log_item     *lip)
{
        struct xfs_cud_log_item *cudp = CUD_ITEM(lip);

        xfs_cui_release(cudp->cud_cuip);
        kmem_cache_free(xfs_cud_zone, cudp);
}

static const struct xfs_item_ops xfs_cud_item_ops = {
        .flags          = XFS_ITEM_RELEASE_WHEN_COMMITTED,
        .iop_size       = xfs_cud_item_size,
        .iop_format     = xfs_cud_item_format,
        .iop_release    = xfs_cud_item_release,
};

static struct xfs_cud_log_item *
xfs_trans_get_cud(
        struct xfs_trans                *tp,
        struct xfs_cui_log_item         *cuip)
{
        struct xfs_cud_log_item         *cudp;

        cudp = kmem_cache_zalloc(xfs_cud_zone, GFP_KERNEL | __GFP_NOFAIL);
        xfs_log_item_init(tp->t_mountp, &cudp->cud_item, XFS_LI_CUD,
                          &xfs_cud_item_ops);
        cudp->cud_cuip = cuip;
        cudp->cud_format.cud_cui_id = cuip->cui_format.cui_id;

        xfs_trans_add_item(tp, &cudp->cud_item);
        return cudp;
}

/*
 * Finish an refcount update and log it to the CUD. Note that the
 * transaction is marked dirty regardless of whether the refcount
 * update succeeds or fails to support the CUI/CUD lifecycle rules.
 */
static int
xfs_trans_log_finish_refcount_update(
        struct xfs_trans                *tp,
        struct xfs_cud_log_item         *cudp,
        enum xfs_refcount_intent_type   type,
        xfs_fsblock_t                   startblock,
        xfs_extlen_t                    blockcount,
        xfs_fsblock_t                   *new_fsb,
        xfs_extlen_t                    *new_len,
        struct xfs_btree_cur            **pcur)
{
        int                             error;

        error = xfs_refcount_finish_one(tp, type, startblock,
                        blockcount, new_fsb, new_len, pcur);

        /*
         * Mark the transaction dirty, even on error. This ensures the
         * transaction is aborted, which:
         *
         * 1.) releases the CUI and frees the CUD
         * 2.) shuts down the filesystem
         */
        tp->t_flags |= XFS_TRANS_DIRTY;
        set_bit(XFS_LI_DIRTY, &cudp->cud_item.li_flags);

        return error;
}

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

        ra = container_of(a, struct xfs_refcount_intent, ri_list);
        rb = container_of(b, struct xfs_refcount_intent, ri_list);
        return  XFS_FSB_TO_AGNO(mp, ra->ri_startblock) -
                XFS_FSB_TO_AGNO(mp, rb->ri_startblock);
}

/* Set the phys extent flags for this reverse mapping. */
static void
xfs_trans_set_refcount_flags(
        struct xfs_phys_extent          *refc,
        enum xfs_refcount_intent_type   type)
{
        refc->pe_flags = 0;
        switch (type) {
        case XFS_REFCOUNT_INCREASE:
        case XFS_REFCOUNT_DECREASE:
        case XFS_REFCOUNT_ALLOC_COW:
        case XFS_REFCOUNT_FREE_COW:
                refc->pe_flags |= type;
                break;
        default:
                ASSERT(0);
        }
}

/* Log refcount updates in the intent item. */
STATIC void
xfs_refcount_update_log_item(
        struct xfs_trans                *tp,
        struct xfs_cui_log_item         *cuip,
        struct xfs_refcount_intent      *refc)
{
        uint                            next_extent;
        struct xfs_phys_extent          *ext;

        tp->t_flags |= XFS_TRANS_DIRTY;
        set_bit(XFS_LI_DIRTY, &cuip->cui_item.li_flags);

        /*
         * 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(&cuip->cui_next_extent) - 1;
        ASSERT(next_extent < cuip->cui_format.cui_nextents);
        ext = &cuip->cui_format.cui_extents[next_extent];
        ext->pe_startblock = refc->ri_startblock;
        ext->pe_len = refc->ri_blockcount;
        xfs_trans_set_refcount_flags(ext, refc->ri_type);
}

static struct xfs_log_item *
xfs_refcount_update_create_intent(
        struct xfs_trans                *tp,
        struct list_head                *items,
        unsigned int                    count,
        bool                            sort)
{
        struct xfs_mount                *mp = tp->t_mountp;
        struct xfs_cui_log_item         *cuip = xfs_cui_init(mp, count);
        struct xfs_refcount_intent      *refc;

        ASSERT(count > 0);

        xfs_trans_add_item(tp, &cuip->cui_item);
        if (sort)
                list_sort(mp, items, xfs_refcount_update_diff_items);
        list_for_each_entry(refc, items, ri_list)
                xfs_refcount_update_log_item(tp, cuip, refc);
        return &cuip->cui_item;
}

/* Get an CUD so we can process all the deferred refcount updates. */
static struct xfs_log_item *
xfs_refcount_update_create_done(
        struct xfs_trans                *tp,
        struct xfs_log_item             *intent,
        unsigned int                    count)
{
        return &xfs_trans_get_cud(tp, CUI_ITEM(intent))->cud_item;
}

/* Process a deferred refcount update. */
STATIC int
xfs_refcount_update_finish_item(
        struct xfs_trans                *tp,
        struct xfs_log_item             *done,
        struct list_head                *item,
        struct xfs_btree_cur            **state)
{
        struct xfs_refcount_intent      *refc;
        xfs_fsblock_t                   new_fsb;
        xfs_extlen_t                    new_aglen;
        int                             error;

        refc = container_of(item, struct xfs_refcount_intent, ri_list);
        error = xfs_trans_log_finish_refcount_update(tp, CUD_ITEM(done),
                        refc->ri_type, refc->ri_startblock, refc->ri_blockcount,
                        &new_fsb, &new_aglen, state);

        /* Did we run out of reservation?  Requeue what we didn't finish. */
        if (!error && new_aglen > 0) {
                ASSERT(refc->ri_type == XFS_REFCOUNT_INCREASE ||
                       refc->ri_type == XFS_REFCOUNT_DECREASE);
                refc->ri_startblock = new_fsb;
                refc->ri_blockcount = new_aglen;
                return -EAGAIN;
        }
        kmem_free(refc);
        return error;
}

/* Abort all pending CUIs. */
STATIC void
xfs_refcount_update_abort_intent(
        struct xfs_log_item             *intent)
{
        xfs_cui_release(CUI_ITEM(intent));
}

/* Cancel a deferred refcount update. */
STATIC void
xfs_refcount_update_cancel_item(
        struct list_head                *item)
{
        struct xfs_refcount_intent      *refc;

        refc = container_of(item, struct xfs_refcount_intent, ri_list);
        kmem_free(refc);
}

const struct xfs_defer_op_type xfs_refcount_update_defer_type = {
        .max_items      = XFS_CUI_MAX_FAST_EXTENTS,
        .create_intent  = xfs_refcount_update_create_intent,
        .abort_intent   = xfs_refcount_update_abort_intent,
        .create_done    = xfs_refcount_update_create_done,
        .finish_item    = xfs_refcount_update_finish_item,
        .finish_cleanup = xfs_refcount_finish_one_cleanup,
        .cancel_item    = xfs_refcount_update_cancel_item,
};

/*
 * Process a refcount update intent item that was recovered from the log.
 * We need to update the refcountbt.
 */
STATIC int
xfs_cui_item_recover(
        struct xfs_log_item             *lip,
        struct list_head                *capture_list)
{
        struct xfs_bmbt_irec            irec;
        struct xfs_cui_log_item         *cuip = CUI_ITEM(lip);
        struct xfs_phys_extent          *refc;
        struct xfs_cud_log_item         *cudp;
        struct xfs_trans                *tp;
        struct xfs_btree_cur            *rcur = NULL;
        struct xfs_mount                *mp = lip->li_mountp;
        xfs_fsblock_t                   startblock_fsb;
        xfs_fsblock_t                   new_fsb;
        xfs_extlen_t                    new_len;
        unsigned int                    refc_type;
        bool                            op_ok;
        bool                            requeue_only = false;
        enum xfs_refcount_intent_type   type;
        int                             i;
        int                             error = 0;

        /*
         * First check the validity of the extents described by the
         * CUI.  If any are bad, then assume that all are bad and
         * just toss the CUI.
         */
        for (i = 0; i < cuip->cui_format.cui_nextents; i++) {
                refc = &cuip->cui_format.cui_extents[i];
                startblock_fsb = XFS_BB_TO_FSB(mp,
                                   XFS_FSB_TO_DADDR(mp, refc->pe_startblock));
                switch (refc->pe_flags & XFS_REFCOUNT_EXTENT_TYPE_MASK) {
                case XFS_REFCOUNT_INCREASE:
                case XFS_REFCOUNT_DECREASE:
                case XFS_REFCOUNT_ALLOC_COW:
                case XFS_REFCOUNT_FREE_COW:
                        op_ok = true;
                        break;
                default:
                        op_ok = false;
                        break;
                }
                if (!op_ok || startblock_fsb == 0 ||
                    refc->pe_len == 0 ||
                    startblock_fsb >= mp->m_sb.sb_dblocks ||
                    refc->pe_len >= mp->m_sb.sb_agblocks ||
                    (refc->pe_flags & ~XFS_REFCOUNT_EXTENT_FLAGS))
                        return -EFSCORRUPTED;
        }

        /*
         * Under normal operation, refcount updates are deferred, so we
         * wouldn't be adding them directly to a transaction.  All
         * refcount updates manage reservation usage internally and
         * dynamically by deferring work that won't fit in the
         * transaction.  Normally, any work that needs to be deferred
         * gets attached to the same defer_ops that scheduled the
         * refcount update.  However, we're in log recovery here, so we
         * use the passed in defer_ops and to finish up any work that
         * doesn't fit.  We need to reserve enough blocks to handle a
         * full btree split on either end of the refcount range.
         */
        error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate,
                        mp->m_refc_maxlevels * 2, 0, XFS_TRANS_RESERVE, &tp);
        if (error)
                return error;

        cudp = xfs_trans_get_cud(tp, cuip);

        for (i = 0; i < cuip->cui_format.cui_nextents; i++) {
                refc = &cuip->cui_format.cui_extents[i];
                refc_type = refc->pe_flags & XFS_REFCOUNT_EXTENT_TYPE_MASK;
                switch (refc_type) {
                case XFS_REFCOUNT_INCREASE:
                case XFS_REFCOUNT_DECREASE:
                case XFS_REFCOUNT_ALLOC_COW:
                case XFS_REFCOUNT_FREE_COW:
                        type = refc_type;
                        break;
                default:
                        XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
                        error = -EFSCORRUPTED;
                        goto abort_error;
                }
                if (requeue_only) {
                        new_fsb = refc->pe_startblock;
                        new_len = refc->pe_len;
                } else
                        error = xfs_trans_log_finish_refcount_update(tp, cudp,
                                type, refc->pe_startblock, refc->pe_len,
                                &new_fsb, &new_len, &rcur);
                if (error)
                        goto abort_error;

                /* Requeue what we didn't finish. */
                if (new_len > 0) {
                        irec.br_startblock = new_fsb;
                        irec.br_blockcount = new_len;
                        switch (type) {
                        case XFS_REFCOUNT_INCREASE:
                                xfs_refcount_increase_extent(tp, &irec);
                                break;
                        case XFS_REFCOUNT_DECREASE:
                                xfs_refcount_decrease_extent(tp, &irec);
                                break;
                        case XFS_REFCOUNT_ALLOC_COW:
                                xfs_refcount_alloc_cow_extent(tp,
                                                irec.br_startblock,
                                                irec.br_blockcount);
                                break;
                        case XFS_REFCOUNT_FREE_COW:
                                xfs_refcount_free_cow_extent(tp,
                                                irec.br_startblock,
                                                irec.br_blockcount);
                                break;
                        default:
                                ASSERT(0);
                        }
                        requeue_only = true;
                }
        }

        xfs_refcount_finish_one_cleanup(tp, rcur, error);
        return xfs_defer_ops_capture_and_commit(tp, NULL, capture_list);

abort_error:
        xfs_refcount_finish_one_cleanup(tp, rcur, error);
        xfs_trans_cancel(tp);
        return error;
}

STATIC bool
xfs_cui_item_match(
        struct xfs_log_item     *lip,
        uint64_t                intent_id)
{
        return CUI_ITEM(lip)->cui_format.cui_id == intent_id;
}

/* Relog an intent item to push the log tail forward. */
static struct xfs_log_item *
xfs_cui_item_relog(
        struct xfs_log_item             *intent,
        struct xfs_trans                *tp)
{
        struct xfs_cud_log_item         *cudp;
        struct xfs_cui_log_item         *cuip;
        struct xfs_phys_extent          *extp;
        unsigned int                    count;

        count = CUI_ITEM(intent)->cui_format.cui_nextents;
        extp = CUI_ITEM(intent)->cui_format.cui_extents;

        tp->t_flags |= XFS_TRANS_DIRTY;
        cudp = xfs_trans_get_cud(tp, CUI_ITEM(intent));
        set_bit(XFS_LI_DIRTY, &cudp->cud_item.li_flags);

        cuip = xfs_cui_init(tp->t_mountp, count);
        memcpy(cuip->cui_format.cui_extents, extp, count * sizeof(*extp));
        atomic_set(&cuip->cui_next_extent, count);
        xfs_trans_add_item(tp, &cuip->cui_item);
        set_bit(XFS_LI_DIRTY, &cuip->cui_item.li_flags);
        return &cuip->cui_item;
}

static const struct xfs_item_ops xfs_cui_item_ops = {
        .iop_size       = xfs_cui_item_size,
        .iop_format     = xfs_cui_item_format,
        .iop_unpin      = xfs_cui_item_unpin,
        .iop_release    = xfs_cui_item_release,
        .iop_recover    = xfs_cui_item_recover,
        .iop_match      = xfs_cui_item_match,
        .iop_relog      = xfs_cui_item_relog,
};

/*
 * Copy an CUI format buffer from the given buf, and into the destination
 * CUI format structure.  The CUI/CUD items were designed not to need any
 * special alignment handling.
 */
static int
xfs_cui_copy_format(
        struct xfs_log_iovec            *buf,
        struct xfs_cui_log_format       *dst_cui_fmt)
{
        struct xfs_cui_log_format       *src_cui_fmt;
        uint                            len;

        src_cui_fmt = buf->i_addr;
        len = xfs_cui_log_format_sizeof(src_cui_fmt->cui_nextents);

        if (buf->i_len == len) {
                memcpy(dst_cui_fmt, src_cui_fmt, len);
                return 0;
        }
        XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, NULL);
        return -EFSCORRUPTED;
}

/*
 * This routine is called to create an in-core extent refcount update
 * item from the cui format structure which was logged on disk.
 * It allocates an in-core cui, copies the extents from the format
 * structure into it, and adds the cui to the AIL with the given
 * LSN.
 */
STATIC int
xlog_recover_cui_commit_pass2(
        struct xlog                     *log,
        struct list_head                *buffer_list,
        struct xlog_recover_item        *item,
        xfs_lsn_t                       lsn)
{
        int                             error;
        struct xfs_mount                *mp = log->l_mp;
        struct xfs_cui_log_item         *cuip;
        struct xfs_cui_log_format       *cui_formatp;

        cui_formatp = item->ri_buf[0].i_addr;

        cuip = xfs_cui_init(mp, cui_formatp->cui_nextents);
        error = xfs_cui_copy_format(&item->ri_buf[0], &cuip->cui_format);
        if (error) {
                xfs_cui_item_free(cuip);
                return error;
        }
        atomic_set(&cuip->cui_next_extent, cui_formatp->cui_nextents);
        /*
         * Insert the intent into the AIL directly and drop one reference so
         * that finishing or canceling the work will drop the other.
         */
        xfs_trans_ail_insert(log->l_ailp, &cuip->cui_item, lsn);
        xfs_cui_release(cuip);
        return 0;
}

const struct xlog_recover_item_ops xlog_cui_item_ops = {
        .item_type              = XFS_LI_CUI,
        .commit_pass2           = xlog_recover_cui_commit_pass2,
};

/*
 * This routine is called when an CUD format structure is found in a committed
 * transaction in the log. Its purpose is to cancel the corresponding CUI if it
 * was still in the log. To do this it searches the AIL for the CUI with an id
 * equal to that in the CUD format structure. If we find it we drop the CUD
 * reference, which removes the CUI from the AIL and frees it.
 */
STATIC int
xlog_recover_cud_commit_pass2(
        struct xlog                     *log,
        struct list_head                *buffer_list,
        struct xlog_recover_item        *item,
        xfs_lsn_t                       lsn)
{
        struct xfs_cud_log_format       *cud_formatp;

        cud_formatp = item->ri_buf[0].i_addr;
        if (item->ri_buf[0].i_len != sizeof(struct xfs_cud_log_format)) {
                XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
                return -EFSCORRUPTED;
        }

        xlog_recover_release_intent(log, XFS_LI_CUI, cud_formatp->cud_cui_id);
        return 0;
}

const struct xlog_recover_item_ops xlog_cud_item_ops = {
        .item_type              = XFS_LI_CUD,
        .commit_pass2           = xlog_recover_cud_commit_pass2,
};