// 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_inode.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_bmap_item.h"
#include "xfs_log.h"
#include "xfs_bmap.h"
#include "xfs_icache.h"
#include "xfs_bmap_btree.h"
#include "xfs_trans_space.h"
#include "xfs_error.h"

kmem_zone_t     *xfs_bui_zone;
kmem_zone_t     *xfs_bud_zone;

static inline struct xfs_bui_log_item *BUI_ITEM(struct xfs_log_item *lip)
{
        return container_of(lip, struct xfs_bui_log_item, bui_item);
}

void
xfs_bui_item_free(
        struct xfs_bui_log_item *buip)
{
        kmem_cache_free(xfs_bui_zone, buip);
}

/*
 * Freeing the BUI requires that we remove it from the AIL if it has already
 * been placed there. However, the BUI may not yet have been placed in the AIL
 * when called by xfs_bui_release() from BUD 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 BUI.
 */
void
xfs_bui_release(
        struct xfs_bui_log_item *buip)
{
        ASSERT(atomic_read(&buip->bui_refcount) > 0);
        if (atomic_dec_and_test(&buip->bui_refcount)) {
                xfs_trans_ail_remove(&buip->bui_item, SHUTDOWN_LOG_IO_ERROR);
                xfs_bui_item_free(buip);
        }
}


STATIC void
xfs_bui_item_size(
        struct xfs_log_item     *lip,
        int                     *nvecs,
        int                     *nbytes)
{
        struct xfs_bui_log_item *buip = BUI_ITEM(lip);

        *nvecs += 1;
        *nbytes += xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents);
}

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

        ASSERT(atomic_read(&buip->bui_next_extent) ==
                        buip->bui_format.bui_nextents);

        buip->bui_format.bui_type = XFS_LI_BUI;
        buip->bui_format.bui_size = 1;

        xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUI_FORMAT, &buip->bui_format,
                        xfs_bui_log_format_sizeof(buip->bui_format.bui_nextents));
}

/*
 * The unpin operation is the last place an BUI 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 BUI transaction has been successfully committed to make it
 * this far. Therefore, we expect whoever committed the BUI to either construct
 * and commit the BUD or drop the BUD's reference in the event of error. Simply
 * drop the log's BUI reference now that the log is done with it.
 */
STATIC void
xfs_bui_item_unpin(
        struct xfs_log_item     *lip,
        int                     remove)
{
        struct xfs_bui_log_item *buip = BUI_ITEM(lip);

        xfs_bui_release(buip);
}

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

static const struct xfs_item_ops xfs_bui_item_ops = {
        .iop_size       = xfs_bui_item_size,
        .iop_format     = xfs_bui_item_format,
        .iop_unpin      = xfs_bui_item_unpin,
        .iop_release    = xfs_bui_item_release,
};

/*
 * Allocate and initialize an bui item with the given number of extents.
 */
struct xfs_bui_log_item *
xfs_bui_init(
        struct xfs_mount                *mp)

{
        struct xfs_bui_log_item         *buip;

        buip = kmem_zone_zalloc(xfs_bui_zone, 0);

        xfs_log_item_init(mp, &buip->bui_item, XFS_LI_BUI, &xfs_bui_item_ops);
        buip->bui_format.bui_nextents = XFS_BUI_MAX_FAST_EXTENTS;
        buip->bui_format.bui_id = (uintptr_t)(void *)buip;
        atomic_set(&buip->bui_next_extent, 0);
        atomic_set(&buip->bui_refcount, 2);

        return buip;
}

static inline struct xfs_bud_log_item *BUD_ITEM(struct xfs_log_item *lip)
{
        return container_of(lip, struct xfs_bud_log_item, bud_item);
}

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

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

        budp->bud_format.bud_type = XFS_LI_BUD;
        budp->bud_format.bud_size = 1;

        xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_BUD_FORMAT, &budp->bud_format,
                        sizeof(struct xfs_bud_log_format));
}

/*
 * The BUD is either committed or aborted if the transaction is cancelled. If
 * the transaction is cancelled, drop our reference to the BUI and free the
 * BUD.
 */
STATIC void
xfs_bud_item_release(
        struct xfs_log_item     *lip)
{
        struct xfs_bud_log_item *budp = BUD_ITEM(lip);

        xfs_bui_release(budp->bud_buip);
        kmem_cache_free(xfs_bud_zone, budp);
}

static const struct xfs_item_ops xfs_bud_item_ops = {
        .flags          = XFS_ITEM_RELEASE_WHEN_COMMITTED,
        .iop_size       = xfs_bud_item_size,
        .iop_format     = xfs_bud_item_format,
        .iop_release    = xfs_bud_item_release,
};

static struct xfs_bud_log_item *
xfs_trans_get_bud(
        struct xfs_trans                *tp,
        struct xfs_bui_log_item         *buip)
{
        struct xfs_bud_log_item         *budp;

        budp = kmem_zone_zalloc(xfs_bud_zone, 0);
        xfs_log_item_init(tp->t_mountp, &budp->bud_item, XFS_LI_BUD,
                          &xfs_bud_item_ops);
        budp->bud_buip = buip;
        budp->bud_format.bud_bui_id = buip->bui_format.bui_id;

        xfs_trans_add_item(tp, &budp->bud_item);
        return budp;
}

/*
 * Finish an bmap update and log it to the BUD. Note that the
 * transaction is marked dirty regardless of whether the bmap update
 * succeeds or fails to support the BUI/BUD lifecycle rules.
 */
static int
xfs_trans_log_finish_bmap_update(
        struct xfs_trans                *tp,
        struct xfs_bud_log_item         *budp,
        enum xfs_bmap_intent_type       type,
        struct xfs_inode                *ip,
        int                             whichfork,
        xfs_fileoff_t                   startoff,
        xfs_fsblock_t                   startblock,
        xfs_filblks_t                   *blockcount,
        xfs_exntst_t                    state)
{
        int                             error;

        error = xfs_bmap_finish_one(tp, ip, type, whichfork, startoff,
                        startblock, blockcount, state);

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

        return error;
}

/* Sort bmap intents by inode. */
static int
xfs_bmap_update_diff_items(
        void                            *priv,
        struct list_head                *a,
        struct list_head                *b)
{
        struct xfs_bmap_intent          *ba;
        struct xfs_bmap_intent          *bb;

        ba = container_of(a, struct xfs_bmap_intent, bi_list);
        bb = container_of(b, struct xfs_bmap_intent, bi_list);
        return ba->bi_owner->i_ino - bb->bi_owner->i_ino;
}

/* Get an BUI. */
STATIC void *
xfs_bmap_update_create_intent(
        struct xfs_trans                *tp,
        unsigned int                    count)
{
        struct xfs_bui_log_item         *buip;

        ASSERT(count == XFS_BUI_MAX_FAST_EXTENTS);
        ASSERT(tp != NULL);

        buip = xfs_bui_init(tp->t_mountp);
        ASSERT(buip != NULL);

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

/* Set the map extent flags for this mapping. */
static void
xfs_trans_set_bmap_flags(
        struct xfs_map_extent           *bmap,
        enum xfs_bmap_intent_type       type,
        int                             whichfork,
        xfs_exntst_t                    state)
{
        bmap->me_flags = 0;
        switch (type) {
        case XFS_BMAP_MAP:
        case XFS_BMAP_UNMAP:
                bmap->me_flags = type;
                break;
        default:
                ASSERT(0);
        }
        if (state == XFS_EXT_UNWRITTEN)
                bmap->me_flags |= XFS_BMAP_EXTENT_UNWRITTEN;
        if (whichfork == XFS_ATTR_FORK)
                bmap->me_flags |= XFS_BMAP_EXTENT_ATTR_FORK;
}

/* Log bmap updates in the intent item. */
STATIC void
xfs_bmap_update_log_item(
        struct xfs_trans                *tp,
        void                            *intent,
        struct list_head                *item)
{
        struct xfs_bui_log_item         *buip = intent;
        struct xfs_bmap_intent          *bmap;
        uint                            next_extent;
        struct xfs_map_extent           *map;

        bmap = container_of(item, struct xfs_bmap_intent, bi_list);

        tp->t_flags |= XFS_TRANS_DIRTY;
        set_bit(XFS_LI_DIRTY, &buip->bui_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(&buip->bui_next_extent) - 1;
        ASSERT(next_extent < buip->bui_format.bui_nextents);
        map = &buip->bui_format.bui_extents[next_extent];
        map->me_owner = bmap->bi_owner->i_ino;
        map->me_startblock = bmap->bi_bmap.br_startblock;
        map->me_startoff = bmap->bi_bmap.br_startoff;
        map->me_len = bmap->bi_bmap.br_blockcount;
        xfs_trans_set_bmap_flags(map, bmap->bi_type, bmap->bi_whichfork,
                        bmap->bi_bmap.br_state);
}

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

/* Process a deferred rmap update. */
STATIC int
xfs_bmap_update_finish_item(
        struct xfs_trans                *tp,
        struct list_head                *item,
        void                            *done_item,
        void                            **state)
{
        struct xfs_bmap_intent          *bmap;
        xfs_filblks_t                   count;
        int                             error;

        bmap = container_of(item, struct xfs_bmap_intent, bi_list);
        count = bmap->bi_bmap.br_blockcount;
        error = xfs_trans_log_finish_bmap_update(tp, done_item,
                        bmap->bi_type,
                        bmap->bi_owner, bmap->bi_whichfork,
                        bmap->bi_bmap.br_startoff,
                        bmap->bi_bmap.br_startblock,
                        &count,
                        bmap->bi_bmap.br_state);
        if (!error && count > 0) {
                ASSERT(bmap->bi_type == XFS_BMAP_UNMAP);
                bmap->bi_bmap.br_blockcount = count;
                return -EAGAIN;
        }
        kmem_free(bmap);
        return error;
}

/* Abort all pending BUIs. */
STATIC void
xfs_bmap_update_abort_intent(
        void                            *intent)
{
        xfs_bui_release(intent);
}

/* Cancel a deferred rmap update. */
STATIC void
xfs_bmap_update_cancel_item(
        struct list_head                *item)
{
        struct xfs_bmap_intent          *bmap;

        bmap = container_of(item, struct xfs_bmap_intent, bi_list);
        kmem_free(bmap);
}

const struct xfs_defer_op_type xfs_bmap_update_defer_type = {
        .max_items      = XFS_BUI_MAX_FAST_EXTENTS,
        .diff_items     = xfs_bmap_update_diff_items,
        .create_intent  = xfs_bmap_update_create_intent,
        .abort_intent   = xfs_bmap_update_abort_intent,
        .log_item       = xfs_bmap_update_log_item,
        .create_done    = xfs_bmap_update_create_done,
        .finish_item    = xfs_bmap_update_finish_item,
        .cancel_item    = xfs_bmap_update_cancel_item,
};

/*
 * Process a bmap update intent item that was recovered from the log.
 * We need to update some inode's bmbt.
 */
int
xfs_bui_recover(
        struct xfs_trans                *parent_tp,
        struct xfs_bui_log_item         *buip)
{
        int                             error = 0;
        unsigned int                    bui_type;
        struct xfs_map_extent           *bmap;
        xfs_fsblock_t                   startblock_fsb;
        xfs_fsblock_t                   inode_fsb;
        xfs_filblks_t                   count;
        bool                            op_ok;
        struct xfs_bud_log_item         *budp;
        enum xfs_bmap_intent_type       type;
        int                             whichfork;
        xfs_exntst_t                    state;
        struct xfs_trans                *tp;
        struct xfs_inode                *ip = NULL;
        struct xfs_bmbt_irec            irec;
        struct xfs_mount                *mp = parent_tp->t_mountp;

        ASSERT(!test_bit(XFS_BUI_RECOVERED, &buip->bui_flags));

        /* Only one mapping operation per BUI... */
        if (buip->bui_format.bui_nextents != XFS_BUI_MAX_FAST_EXTENTS) {
                set_bit(XFS_BUI_RECOVERED, &buip->bui_flags);
                xfs_bui_release(buip);
                return -EFSCORRUPTED;
        }

        /*
         * First check the validity of the extent described by the
         * BUI.  If anything is bad, then toss the BUI.
         */
        bmap = &buip->bui_format.bui_extents[0];
        startblock_fsb = XFS_BB_TO_FSB(mp,
                           XFS_FSB_TO_DADDR(mp, bmap->me_startblock));
        inode_fsb = XFS_BB_TO_FSB(mp, XFS_FSB_TO_DADDR(mp,
                        XFS_INO_TO_FSB(mp, bmap->me_owner)));
        switch (bmap->me_flags & XFS_BMAP_EXTENT_TYPE_MASK) {
        case XFS_BMAP_MAP:
        case XFS_BMAP_UNMAP:
                op_ok = true;
                break;
        default:
                op_ok = false;
                break;
        }
        if (!op_ok || startblock_fsb == 0 ||
            bmap->me_len == 0 ||
            inode_fsb == 0 ||
            startblock_fsb >= mp->m_sb.sb_dblocks ||
            bmap->me_len >= mp->m_sb.sb_agblocks ||
            inode_fsb >= mp->m_sb.sb_dblocks ||
            (bmap->me_flags & ~XFS_BMAP_EXTENT_FLAGS)) {
                /*
                 * This will pull the BUI from the AIL and
                 * free the memory associated with it.
                 */
                set_bit(XFS_BUI_RECOVERED, &buip->bui_flags);
                xfs_bui_release(buip);
                return -EFSCORRUPTED;
        }

        error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate,
                        XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK), 0, 0, &tp);
        if (error)
                return error;
        /*
         * Recovery stashes all deferred ops during intent processing and
         * finishes them on completion. Transfer current dfops state to this
         * transaction and transfer the result back before we return.
         */
        xfs_defer_move(tp, parent_tp);
        budp = xfs_trans_get_bud(tp, buip);

        /* Grab the inode. */
        error = xfs_iget(mp, tp, bmap->me_owner, 0, XFS_ILOCK_EXCL, &ip);
        if (error)
                goto err_inode;

        if (VFS_I(ip)->i_nlink == 0)
                xfs_iflags_set(ip, XFS_IRECOVERY);

        /* Process deferred bmap item. */
        state = (bmap->me_flags & XFS_BMAP_EXTENT_UNWRITTEN) ?
                        XFS_EXT_UNWRITTEN : XFS_EXT_NORM;
        whichfork = (bmap->me_flags & XFS_BMAP_EXTENT_ATTR_FORK) ?
                        XFS_ATTR_FORK : XFS_DATA_FORK;
        bui_type = bmap->me_flags & XFS_BMAP_EXTENT_TYPE_MASK;
        switch (bui_type) {
        case XFS_BMAP_MAP:
        case XFS_BMAP_UNMAP:
                type = bui_type;
                break;
        default:
                XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
                error = -EFSCORRUPTED;
                goto err_inode;
        }
        xfs_trans_ijoin(tp, ip, 0);

        count = bmap->me_len;
        error = xfs_trans_log_finish_bmap_update(tp, budp, type, ip, whichfork,
                        bmap->me_startoff, bmap->me_startblock, &count, state);
        if (error)
                goto err_inode;

        if (count > 0) {
                ASSERT(type == XFS_BMAP_UNMAP);
                irec.br_startblock = bmap->me_startblock;
                irec.br_blockcount = count;
                irec.br_startoff = bmap->me_startoff;
                irec.br_state = state;
                xfs_bmap_unmap_extent(tp, ip, &irec);
        }

        set_bit(XFS_BUI_RECOVERED, &buip->bui_flags);
        xfs_defer_move(parent_tp, tp);
        error = xfs_trans_commit(tp);
        xfs_iunlock(ip, XFS_ILOCK_EXCL);
        xfs_irele(ip);

        return error;

err_inode:
        xfs_defer_move(parent_tp, tp);
        xfs_trans_cancel(tp);
        if (ip) {
                xfs_iunlock(ip, XFS_ILOCK_EXCL);
                xfs_irele(ip);
        }
        return error;
}