/*
 * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * 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.
 *
 * 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_sb.h"
#include "xfs_mount.h"
#include "xfs_btree.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_cksum.h"
#include "xfs_trans.h"


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_private.a.agbp, cur->bc_private.a.agno,
                        cur->bc_btnum);
}

STATIC void
xfs_allocbt_set_root(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *ptr,
        int                     inc)
{
        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
        xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
        int                     btnum = cur->bc_btnum;
        struct xfs_perag        *pag = xfs_perag_get(cur->bc_mp, seqno);

        ASSERT(ptr->s != 0);

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

        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,
        union xfs_btree_ptr     *start,
        union xfs_btree_ptr     *new,
        int                     *stat)
{
        int                     error;
        xfs_agblock_t           bno;

        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);

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

        if (bno == NULLAGBLOCK) {
                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
                *stat = 0;
                return 0;
        }

        xfs_extent_busy_reuse(cur->bc_mp, cur->bc_private.a.agno, bno, 1, false);

        xfs_trans_agbtree_delta(cur->bc_tp, 1);
        new->s = cpu_to_be32(bno);

        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
        *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_private.a.agbp;
        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
        xfs_agblock_t           bno;
        int                     error;

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

        xfs_extent_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1,
                              XFS_EXTENT_BUSY_SKIP_DISCARD);
        xfs_trans_agbtree_delta(cur->bc_tp, -1);
        return 0;
}

/*
 * Update the longest extent in the AGF
 */
STATIC void
xfs_allocbt_update_lastrec(
        struct xfs_btree_cur    *cur,
        struct xfs_btree_block  *block,
        union xfs_btree_rec     *rec,
        int                     ptr,
        int                     reason)
{
        struct xfs_agf          *agf = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);
        xfs_agnumber_t          seqno = be32_to_cpu(agf->agf_seqno);
        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 = xfs_perag_get(cur->bc_mp, seqno);
        pag->pagf_longest = be32_to_cpu(len);
        xfs_perag_put(pag);
        xfs_alloc_log_agf(cur->bc_tp, cur->bc_private.a.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,
        union xfs_btree_rec     *rec)
{
        ASSERT(rec->alloc.ar_startblock != 0);

        key->alloc.ar_startblock = rec->alloc.ar_startblock;
        key->alloc.ar_blockcount = rec->alloc.ar_blockcount;
}

STATIC void
xfs_allocbt_init_rec_from_key(
        union xfs_btree_key     *key,
        union xfs_btree_rec     *rec)
{
        ASSERT(key->alloc.ar_startblock != 0);

        rec->alloc.ar_startblock = key->alloc.ar_startblock;
        rec->alloc.ar_blockcount = key->alloc.ar_blockcount;
}

STATIC void
xfs_allocbt_init_rec_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_rec     *rec)
{
        ASSERT(cur->bc_rec.a.ar_startblock != 0);

        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 = XFS_BUF_TO_AGF(cur->bc_private.a.agbp);

        ASSERT(cur->bc_private.a.agno == be32_to_cpu(agf->agf_seqno));
        ASSERT(agf->agf_roots[cur->bc_btnum] != 0);

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

STATIC __int64_t
xfs_allocbt_key_diff(
        struct xfs_btree_cur    *cur,
        union xfs_btree_key     *key)
{
        xfs_alloc_rec_incore_t  *rec = &cur->bc_rec.a;
        xfs_alloc_key_t         *kp = &key->alloc;
        __int64_t               diff;

        if (cur->bc_btnum == XFS_BTNUM_BNO) {
                return (__int64_t)be32_to_cpu(kp->ar_startblock) -
                                rec->ar_startblock;
        }

        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 bool
xfs_allocbt_verify(
        struct xfs_buf          *bp)
{
        struct xfs_mount        *mp = bp->b_target->bt_mount;
        struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
        struct xfs_perag        *pag = bp->b_pag;
        unsigned int            level;

        /*
         * magic number and level verification
         *
         * During growfs operations, we can't verify the exact level or owner as
         * the perag is not fully initialised and hence not attached to the
         * buffer.  In this case, check against the maximum tree depth.
         *
         * Similarly, during log recovery we will have a perag structure
         * attached, but the agf information will not yet have been initialised
         * from the on disk AGF. Again, we can only check against maximum limits
         * in this case.
         */
        level = be16_to_cpu(block->bb_level);
        switch (block->bb_magic) {
        case cpu_to_be32(XFS_ABTB_CRC_MAGIC):
                if (!xfs_btree_sblock_v5hdr_verify(bp))
                        return false;
                /* fall through */
        case cpu_to_be32(XFS_ABTB_MAGIC):
                if (pag && pag->pagf_init) {
                        if (level >= pag->pagf_levels[XFS_BTNUM_BNOi])
                                return false;
                } else if (level >= mp->m_ag_maxlevels)
                        return false;
                break;
        case cpu_to_be32(XFS_ABTC_CRC_MAGIC):
                if (!xfs_btree_sblock_v5hdr_verify(bp))
                        return false;
                /* fall through */
        case cpu_to_be32(XFS_ABTC_MAGIC):
                if (pag && pag->pagf_init) {
                        if (level >= pag->pagf_levels[XFS_BTNUM_CNTi])
                                return false;
                } else if (level >= mp->m_ag_maxlevels)
                        return false;
                break;
        default:
                return false;
        }

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

static void
xfs_allocbt_read_verify(
        struct xfs_buf  *bp)
{
        if (!xfs_btree_sblock_verify_crc(bp))
                xfs_buf_ioerror(bp, -EFSBADCRC);
        else if (!xfs_allocbt_verify(bp))
                xfs_buf_ioerror(bp, -EFSCORRUPTED);

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

static void
xfs_allocbt_write_verify(
        struct xfs_buf  *bp)
{
        if (!xfs_allocbt_verify(bp)) {
                trace_xfs_btree_corrupt(bp, _RET_IP_);
                xfs_buf_ioerror(bp, -EFSCORRUPTED);
                xfs_verifier_error(bp);
                return;
        }
        xfs_btree_sblock_calc_crc(bp);

}

const struct xfs_buf_ops xfs_allocbt_buf_ops = {
        .name = "xfs_allocbt",
        .verify_read = xfs_allocbt_read_verify,
        .verify_write = xfs_allocbt_write_verify,
};


#if defined(DEBUG) || defined(XFS_WARN)
STATIC int
xfs_allocbt_keys_inorder(
        struct xfs_btree_cur    *cur,
        union xfs_btree_key     *k1,
        union xfs_btree_key     *k2)
{
        if (cur->bc_btnum == XFS_BTNUM_BNO) {
                return be32_to_cpu(k1->alloc.ar_startblock) <
                       be32_to_cpu(k2->alloc.ar_startblock);
        } else {
                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_allocbt_recs_inorder(
        struct xfs_btree_cur    *cur,
        union xfs_btree_rec     *r1,
        union xfs_btree_rec     *r2)
{
        if (cur->bc_btnum == XFS_BTNUM_BNO) {
                return be32_to_cpu(r1->alloc.ar_startblock) +
                        be32_to_cpu(r1->alloc.ar_blockcount) <=
                        be32_to_cpu(r2->alloc.ar_startblock);
        } else {
                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));
        }
}
#endif  /* DEBUG */

static const struct xfs_btree_ops xfs_allocbt_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_rec_from_key      = xfs_allocbt_init_rec_from_key,
        .init_rec_from_cur      = xfs_allocbt_init_rec_from_cur,
        .init_ptr_from_cur      = xfs_allocbt_init_ptr_from_cur,
        .key_diff               = xfs_allocbt_key_diff,
        .buf_ops                = &xfs_allocbt_buf_ops,
#if defined(DEBUG) || defined(XFS_WARN)
        .keys_inorder           = xfs_allocbt_keys_inorder,
        .recs_inorder           = xfs_allocbt_recs_inorder,
#endif
};

/*
 * 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 */
        xfs_agnumber_t          agno,           /* allocation group number */
        xfs_btnum_t             btnum)          /* btree identifier */
{
        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
        struct xfs_btree_cur    *cur;

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

        cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);

        cur->bc_tp = tp;
        cur->bc_mp = mp;
        cur->bc_btnum = btnum;
        cur->bc_blocklog = mp->m_sb.sb_blocklog;
        cur->bc_ops = &xfs_allocbt_ops;

        if (btnum == XFS_BTNUM_CNT) {
                cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
                cur->bc_flags = XFS_BTREE_LASTREC_UPDATE;
        } else {
                cur->bc_nlevels = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
        }

        cur->bc_private.a.agbp = agbp;
        cur->bc_private.a.agno = agno;

        if (xfs_sb_version_hascrc(&mp->m_sb))
                cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;

        return cur;
}

/*
 * 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);

        if (leaf)
                return blocklen / sizeof(xfs_alloc_rec_t);
        return blocklen / (sizeof(xfs_alloc_key_t) + sizeof(xfs_alloc_ptr_t));
}