// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#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_btree.h"
#include "xfs_btree_staging.h"
#include "xfs_alloc_btree.h"
#include "xfs_alloc.h"
#include "xfs_extent_busy.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_trans.h"
#include "xfs_ag.h"

static struct kmem_cache        *xfs_allocbt_cur_cache;

STATIC struct xfs_btree_cur *
xfs_allocbt_dup_cursor(
        struct xfs_btree_cur    *cur)
{
        return xfs_allocbt_init_cursor(cur->bc_mp, cur->bc_tp,
                        cur->bc_ag.agbp, cur->bc_ag.pag, cur->bc_btnum);
}

STATIC void
xfs_allocbt_set_root(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_ptr       *ptr,
        int                             inc)
{
        struct xfs_buf          *agbp = cur->bc_ag.agbp;
        struct xfs_agf          *agf = agbp->b_addr;
        int                     btnum = cur->bc_btnum;

        ASSERT(ptr->s != 0);

        agf->agf_roots[btnum] = ptr->s;
        be32_add_cpu(&agf->agf_levels[btnum], inc);
        cur->bc_ag.pag->pagf_levels[btnum] += inc;

        xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);
}

STATIC int
xfs_allocbt_alloc_block(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_ptr       *start,
        union xfs_btree_ptr             *new,
        int                             *stat)
{
        int                     error;
        xfs_agblock_t           bno;

        /* Allocate the new block from the freelist. If we can't, give up.  */
        error = xfs_alloc_get_freelist(cur->bc_tp, cur->bc_ag.agbp,
                                       &bno, 1);
        if (error)
                return error;

        if (bno == NULLAGBLOCK) {
                *stat = 0;
                return 0;
        }

        atomic64_inc(&cur->bc_mp->m_allocbt_blks);
        xfs_extent_busy_reuse(cur->bc_mp, cur->bc_ag.agbp->b_pag, bno, 1, false);

        new->s = cpu_to_be32(bno);

        *stat = 1;
        return 0;
}

STATIC int
xfs_allocbt_free_block(
        struct xfs_btree_cur    *cur,
        struct xfs_buf          *bp)
{
        struct xfs_buf          *agbp = cur->bc_ag.agbp;
        xfs_agblock_t           bno;
        int                     error;

        bno = xfs_daddr_to_agbno(cur->bc_mp, xfs_buf_daddr(bp));
        error = xfs_alloc_put_freelist(cur->bc_tp, agbp, NULL, bno, 1);
        if (error)
                return error;

        atomic64_dec(&cur->bc_mp->m_allocbt_blks);
        xfs_extent_busy_insert(cur->bc_tp, agbp->b_pag, bno, 1,
                              XFS_EXTENT_BUSY_SKIP_DISCARD);
        return 0;
}

/*
 * Update the longest extent in the AGF
 */
STATIC void
xfs_allocbt_update_lastrec(
        struct xfs_btree_cur            *cur,
        const struct xfs_btree_block    *block,
        const union xfs_btree_rec       *rec,
        int                             ptr,
        int                             reason)
{
        struct xfs_agf          *agf = cur->bc_ag.agbp->b_addr;
        struct xfs_perag        *pag;
        __be32                  len;
        int                     numrecs;

        ASSERT(cur->bc_btnum == XFS_BTNUM_CNT);

        switch (reason) {
        case LASTREC_UPDATE:
                /*
                 * If this is the last leaf block and it's the last record,
                 * then update the size of the longest extent in the AG.
                 */
                if (ptr != xfs_btree_get_numrecs(block))
                        return;
                len = rec->alloc.ar_blockcount;
                break;
        case LASTREC_INSREC:
                if (be32_to_cpu(rec->alloc.ar_blockcount) <=
                    be32_to_cpu(agf->agf_longest))
                        return;
                len = rec->alloc.ar_blockcount;
                break;
        case LASTREC_DELREC:
                numrecs = xfs_btree_get_numrecs(block);
                if (ptr <= numrecs)
                        return;
                ASSERT(ptr == numrecs + 1);

                if (numrecs) {
                        xfs_alloc_rec_t *rrp;

                        rrp = XFS_ALLOC_REC_ADDR(cur->bc_mp, block, numrecs);
                        len = rrp->ar_blockcount;
                } else {
                        len = 0;
                }

                break;
        default:
                ASSERT(0);
                return;
        }

        agf->agf_longest = len;
        pag = cur->bc_ag.agbp->b_pag;
        pag->pagf_longest = be32_to_cpu(len);
        xfs_alloc_log_agf(cur->bc_tp, cur->bc_ag.agbp, XFS_AGF_LONGEST);
}

STATIC int
xfs_allocbt_get_minrecs(
        struct xfs_btree_cur    *cur,
        int                     level)
{
        return cur->bc_mp->m_alloc_mnr[level != 0];
}

STATIC int
xfs_allocbt_get_maxrecs(
        struct xfs_btree_cur    *cur,
        int                     level)
{
        return cur->bc_mp->m_alloc_mxr[level != 0];
}

STATIC void
xfs_allocbt_init_key_from_rec(
        union xfs_btree_key             *key,
        const union xfs_btree_rec       *rec)
{
        key->alloc.ar_startblock = rec->alloc.ar_startblock;
        key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
}

STATIC void
xfs_bnobt_init_high_key_from_rec(
        union xfs_btree_key             *key,
        const union xfs_btree_rec       *rec)
{
        __u32                           x;

        x = be32_to_cpu(rec->alloc.ar_startblock);
        x += be32_to_cpu(rec->alloc.ar_blockcount) - 1;
        key->alloc.ar_startblock = cpu_to_be32(x);
        key->alloc.ar_blockcount = 0;
}

STATIC void
xfs_cntbt_init_high_key_from_rec(
        union xfs_btree_key             *key,
        const union xfs_btree_rec       *rec)
{
        key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
        key->alloc.ar_startblock = 0;
}

STATIC void
xfs_allocbt_init_rec_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_rec     *rec)
{
        rec->alloc.ar_startblock = cpu_to_be32(cur->bc_rec.a.ar_startblock);
        rec->alloc.ar_blockcount = cpu_to_be32(cur->bc_rec.a.ar_blockcount);
}

STATIC void
xfs_allocbt_init_ptr_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *ptr)
{
        struct xfs_agf          *agf = cur->bc_ag.agbp->b_addr;

        ASSERT(cur->bc_ag.pag->pag_agno == be32_to_cpu(agf->agf_seqno));

        ptr->s = agf->agf_roots[cur->bc_btnum];
}

STATIC int64_t
xfs_bnobt_key_diff(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key)
{
        struct xfs_alloc_rec_incore     *rec = &cur->bc_rec.a;
        const struct xfs_alloc_rec      *kp = &key->alloc;

        return (int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
}

STATIC int64_t
xfs_cntbt_key_diff(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *key)
{
        struct xfs_alloc_rec_incore     *rec = &cur->bc_rec.a;
        const struct xfs_alloc_rec      *kp = &key->alloc;
        int64_t                         diff;

        diff = (int64_t)be32_to_cpu(kp->ar_blockcount) - rec->ar_blockcount;
        if (diff)
                return diff;

        return (int64_t)be32_to_cpu(kp->ar_startblock) - rec->ar_startblock;
}

STATIC int64_t
xfs_bnobt_diff_two_keys(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *k1,
        const union xfs_btree_key       *k2)
{
        return (int64_t)be32_to_cpu(k1->alloc.ar_startblock) -
                          be32_to_cpu(k2->alloc.ar_startblock);
}

STATIC int64_t
xfs_cntbt_diff_two_keys(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *k1,
        const union xfs_btree_key       *k2)
{
        int64_t                         diff;

        diff =  be32_to_cpu(k1->alloc.ar_blockcount) -
                be32_to_cpu(k2->alloc.ar_blockcount);
        if (diff)
                return diff;

        return  be32_to_cpu(k1->alloc.ar_startblock) -
                be32_to_cpu(k2->alloc.ar_startblock);
}

static xfs_failaddr_t
xfs_allocbt_verify(
        struct xfs_buf          *bp)
{
        struct xfs_mount        *mp = bp->b_mount;
        struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
        struct xfs_perag        *pag = bp->b_pag;
        xfs_failaddr_t          fa;
        unsigned int            level;
        xfs_btnum_t             btnum = XFS_BTNUM_BNOi;

        if (!xfs_verify_magic(bp, block->bb_magic))
                return __this_address;

        if (xfs_has_crc(mp)) {
                fa = xfs_btree_sblock_v5hdr_verify(bp);
                if (fa)
                        return fa;
        }

        /*
         * The perag may not be attached during grow operations or fully
         * initialized from the AGF during log recovery. Therefore we can only
         * check against maximum tree depth from those contexts.
         *
         * Otherwise check against the per-tree limit. Peek at one of the
         * verifier magic values to determine the type of tree we're verifying
         * against.
         */
        level = be16_to_cpu(block->bb_level);
        if (bp->b_ops->magic[0] == cpu_to_be32(XFS_ABTC_MAGIC))
                btnum = XFS_BTNUM_CNTi;
        if (pag && pag->pagf_init) {
                if (level >= pag->pagf_levels[btnum])
                        return __this_address;
        } else if (level >= mp->m_alloc_maxlevels)
                return __this_address;

        return xfs_btree_sblock_verify(bp, mp->m_alloc_mxr[level != 0]);
}

static void
xfs_allocbt_read_verify(
        struct xfs_buf  *bp)
{
        xfs_failaddr_t  fa;

        if (!xfs_btree_sblock_verify_crc(bp))
                xfs_verifier_error(bp, -EFSBADCRC, __this_address);
        else {
                fa = xfs_allocbt_verify(bp);
                if (fa)
                        xfs_verifier_error(bp, -EFSCORRUPTED, fa);
        }

        if (bp->b_error)
                trace_xfs_btree_corrupt(bp, _RET_IP_);
}

static void
xfs_allocbt_write_verify(
        struct xfs_buf  *bp)
{
        xfs_failaddr_t  fa;

        fa = xfs_allocbt_verify(bp);
        if (fa) {
                trace_xfs_btree_corrupt(bp, _RET_IP_);
                xfs_verifier_error(bp, -EFSCORRUPTED, fa);
                return;
        }
        xfs_btree_sblock_calc_crc(bp);

}

const struct xfs_buf_ops xfs_bnobt_buf_ops = {
        .name = "xfs_bnobt",
        .magic = { cpu_to_be32(XFS_ABTB_MAGIC),
                   cpu_to_be32(XFS_ABTB_CRC_MAGIC) },
        .verify_read = xfs_allocbt_read_verify,
        .verify_write = xfs_allocbt_write_verify,
        .verify_struct = xfs_allocbt_verify,
};

const struct xfs_buf_ops xfs_cntbt_buf_ops = {
        .name = "xfs_cntbt",
        .magic = { cpu_to_be32(XFS_ABTC_MAGIC),
                   cpu_to_be32(XFS_ABTC_CRC_MAGIC) },
        .verify_read = xfs_allocbt_read_verify,
        .verify_write = xfs_allocbt_write_verify,
        .verify_struct = xfs_allocbt_verify,
};

STATIC int
xfs_bnobt_keys_inorder(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *k1,
        const union xfs_btree_key       *k2)
{
        return be32_to_cpu(k1->alloc.ar_startblock) <
               be32_to_cpu(k2->alloc.ar_startblock);
}

STATIC int
xfs_bnobt_recs_inorder(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_rec       *r1,
        const union xfs_btree_rec       *r2)
{
        return be32_to_cpu(r1->alloc.ar_startblock) +
                be32_to_cpu(r1->alloc.ar_blockcount) <=
                be32_to_cpu(r2->alloc.ar_startblock);
}

STATIC int
xfs_cntbt_keys_inorder(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_key       *k1,
        const union xfs_btree_key       *k2)
{
        return be32_to_cpu(k1->alloc.ar_blockcount) <
                be32_to_cpu(k2->alloc.ar_blockcount) ||
                (k1->alloc.ar_blockcount == k2->alloc.ar_blockcount &&
                 be32_to_cpu(k1->alloc.ar_startblock) <
                 be32_to_cpu(k2->alloc.ar_startblock));
}

STATIC int
xfs_cntbt_recs_inorder(
        struct xfs_btree_cur            *cur,
        const union xfs_btree_rec       *r1,
        const union xfs_btree_rec       *r2)
{
        return be32_to_cpu(r1->alloc.ar_blockcount) <
                be32_to_cpu(r2->alloc.ar_blockcount) ||
                (r1->alloc.ar_blockcount == r2->alloc.ar_blockcount &&
                 be32_to_cpu(r1->alloc.ar_startblock) <
                 be32_to_cpu(r2->alloc.ar_startblock));
}

static const struct xfs_btree_ops xfs_bnobt_ops = {
        .rec_len                = sizeof(xfs_alloc_rec_t),
        .key_len                = sizeof(xfs_alloc_key_t),

        .dup_cursor             = xfs_allocbt_dup_cursor,
        .set_root               = xfs_allocbt_set_root,
        .alloc_block            = xfs_allocbt_alloc_block,
        .free_block             = xfs_allocbt_free_block,
        .update_lastrec         = xfs_allocbt_update_lastrec,
        .get_minrecs            = xfs_allocbt_get_minrecs,
        .get_maxrecs            = xfs_allocbt_get_maxrecs,
        .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
        .init_high_key_from_rec = xfs_bnobt_init_high_key_from_rec,
        .init_rec_from_cur      = xfs_allocbt_init_rec_from_cur,
        .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
        .key_diff               = xfs_bnobt_key_diff,
        .buf_ops                = &xfs_bnobt_buf_ops,
        .diff_two_keys          = xfs_bnobt_diff_two_keys,
        .keys_inorder           = xfs_bnobt_keys_inorder,
        .recs_inorder           = xfs_bnobt_recs_inorder,
};

static const struct xfs_btree_ops xfs_cntbt_ops = {
        .rec_len                = sizeof(xfs_alloc_rec_t),
        .key_len                = sizeof(xfs_alloc_key_t),

        .dup_cursor             = xfs_allocbt_dup_cursor,
        .set_root               = xfs_allocbt_set_root,
        .alloc_block            = xfs_allocbt_alloc_block,
        .free_block             = xfs_allocbt_free_block,
        .update_lastrec         = xfs_allocbt_update_lastrec,
        .get_minrecs            = xfs_allocbt_get_minrecs,
        .get_maxrecs            = xfs_allocbt_get_maxrecs,
        .init_key_from_rec      = xfs_allocbt_init_key_from_rec,
        .init_high_key_from_rec = xfs_cntbt_init_high_key_from_rec,
        .init_rec_from_cur      = xfs_allocbt_init_rec_from_cur,
        .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
        .key_diff               = xfs_cntbt_key_diff,
        .buf_ops                = &xfs_cntbt_buf_ops,
        .diff_two_keys          = xfs_cntbt_diff_two_keys,
        .keys_inorder           = xfs_cntbt_keys_inorder,
        .recs_inorder           = xfs_cntbt_recs_inorder,
};

/* Allocate most of a new allocation btree cursor. */
STATIC struct xfs_btree_cur *
xfs_allocbt_init_common(
        struct xfs_mount        *mp,
        struct xfs_trans        *tp,
        struct xfs_perag        *pag,
        xfs_btnum_t             btnum)
{
        struct xfs_btree_cur    *cur;

        ASSERT(btnum == XFS_BTNUM_BNO || btnum == XFS_BTNUM_CNT);

        cur = xfs_btree_alloc_cursor(mp, tp, btnum, mp->m_alloc_maxlevels,
                        xfs_allocbt_cur_cache);
        cur->bc_ag.abt.active = false;

        if (btnum == XFS_BTNUM_CNT) {
                cur->bc_ops = &xfs_cntbt_ops;
                cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_abtc_2);
                cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
        } else {
                cur->bc_ops = &xfs_bnobt_ops;
                cur->bc_statoff = XFS_STATS_CALC_INDEX(xs_abtb_2);
        }

        /* take a reference for the cursor */
        atomic_inc(&pag->pag_ref);
        cur->bc_ag.pag = pag;

        if (xfs_has_crc(mp))
                cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;

        return cur;
}

/*
 * Allocate a new allocation btree cursor.
 */
struct xfs_btree_cur *                  /* new alloc btree cursor */
xfs_allocbt_init_cursor(
        struct xfs_mount        *mp,            /* file system mount point */
        struct xfs_trans        *tp,            /* transaction pointer */
        struct xfs_buf          *agbp,          /* buffer for agf structure */
        struct xfs_perag        *pag,
        xfs_btnum_t             btnum)          /* btree identifier */
{
        struct xfs_agf          *agf = agbp->b_addr;
        struct xfs_btree_cur    *cur;

        cur = xfs_allocbt_init_common(mp, tp, pag, btnum);
        if (btnum == XFS_BTNUM_CNT)
                cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
        else
                cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);

        cur->bc_ag.agbp = agbp;

        return cur;
}

/* Create a free space btree cursor with a fake root for staging. */
struct xfs_btree_cur *
xfs_allocbt_stage_cursor(
        struct xfs_mount        *mp,
        struct xbtree_afakeroot *afake,
        struct xfs_perag        *pag,
        xfs_btnum_t             btnum)
{
        struct xfs_btree_cur    *cur;

        cur = xfs_allocbt_init_common(mp, NULL, pag, btnum);
        xfs_btree_stage_afakeroot(cur, afake);
        return cur;
}

/*
 * Install a new free space btree root.  Caller is responsible for invalidating
 * and freeing the old btree blocks.
 */
void
xfs_allocbt_commit_staged_btree(
        struct xfs_btree_cur    *cur,
        struct xfs_trans        *tp,
        struct xfs_buf          *agbp)
{
        struct xfs_agf          *agf = agbp->b_addr;
        struct xbtree_afakeroot *afake = cur->bc_ag.afake;

        ASSERT(cur->bc_flags & XFS_BTREE_STAGING);

        agf->agf_roots[cur->bc_btnum] = cpu_to_be32(afake->af_root);
        agf->agf_levels[cur->bc_btnum] = cpu_to_be32(afake->af_levels);
        xfs_alloc_log_agf(tp, agbp, XFS_AGF_ROOTS | XFS_AGF_LEVELS);

        if (cur->bc_btnum == XFS_BTNUM_BNO) {
                xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_bnobt_ops);
        } else {
                cur->bc_flags |= XFS_BTREE_LASTREC_UPDATE;
                xfs_btree_commit_afakeroot(cur, tp, agbp, &xfs_cntbt_ops);
        }
}

/* Calculate number of records in an alloc btree block. */
static inline unsigned int
xfs_allocbt_block_maxrecs(
        unsigned int            blocklen,
        bool                    leaf)
{
        if (leaf)
                return blocklen / sizeof(xfs_alloc_rec_t);
        return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
}

/*
 * Calculate number of records in an alloc btree block.
 */
int
xfs_allocbt_maxrecs(
        struct xfs_mount        *mp,
        int                     blocklen,
        int                     leaf)
{
        blocklen -= XFS_ALLOC_BLOCK_LEN(mp);
        return xfs_allocbt_block_maxrecs(blocklen, leaf);
}

/* Free space btrees are at their largest when every other block is free. */
#define XFS_MAX_FREESP_RECORDS  ((XFS_MAX_AG_BLOCKS + 1) / 2)

/* Compute the max possible height for free space btrees. */
unsigned int
xfs_allocbt_maxlevels_ondisk(void)
{
        unsigned int            minrecs[2];
        unsigned int            blocklen;

        blocklen = min(XFS_MIN_BLOCKSIZE - XFS_BTREE_SBLOCK_LEN,
                       XFS_MIN_CRC_BLOCKSIZE - XFS_BTREE_SBLOCK_CRC_LEN);

        minrecs[0] = xfs_allocbt_block_maxrecs(blocklen, true) / 2;
        minrecs[1] = xfs_allocbt_block_maxrecs(blocklen, false) / 2;

        return xfs_btree_compute_maxlevels(minrecs, XFS_MAX_FREESP_RECORDS);
}

/* Calculate the freespace btree size for some records. */
xfs_extlen_t
xfs_allocbt_calc_size(
        struct xfs_mount        *mp,
        unsigned long long      len)
{
        return xfs_btree_calc_size(mp->m_alloc_mnr, len);
}

int __init
xfs_allocbt_init_cur_cache(void)
{
        xfs_allocbt_cur_cache = kmem_cache_create("xfs_bnobt_cur",
                        xfs_btree_cur_sizeof(xfs_allocbt_maxlevels_ondisk()),
                        0, 0, NULL);

        if (!xfs_allocbt_cur_cache)
                return -ENOMEM;
        return 0;
}

void
xfs_allocbt_destroy_cur_cache(void)
{
        kmem_cache_destroy(xfs_allocbt_cur_cache);
        xfs_allocbt_cur_cache = NULL;
}