[people/arne_f/kernel.git] / fs / xfs / libxfs / xfs_refcount_btree.c

/*
 * 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_sb.h"
#include "xfs_mount.h"
#include "xfs_btree.h"
#include "xfs_bmap.h"
#include "xfs_refcount_btree.h"
#include "xfs_alloc.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_cksum.h"
#include "xfs_trans.h"
#include "xfs_bit.h"
#include "xfs_rmap.h"

static struct xfs_btree_cur *
xfs_refcountbt_dup_cursor(
        struct xfs_btree_cur    *cur)
{
        return xfs_refcountbt_init_cursor(cur->bc_mp, cur->bc_tp,
                        cur->bc_private.a.agbp, cur->bc_private.a.agno,
                        cur->bc_private.a.dfops);
}

STATIC void
xfs_refcountbt_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);
        struct xfs_perag        *pag = xfs_perag_get(cur->bc_mp, seqno);

        ASSERT(ptr->s != 0);

        agf->agf_refcount_root = ptr->s;
        be32_add_cpu(&agf->agf_refcount_level, inc);
        pag->pagf_refcount_level += inc;
        xfs_perag_put(pag);

        xfs_alloc_log_agf(cur->bc_tp, agbp,
                        XFS_AGF_REFCOUNT_ROOT | XFS_AGF_REFCOUNT_LEVEL);
}

STATIC int
xfs_refcountbt_alloc_block(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *start,
        union xfs_btree_ptr     *new,
        int                     *stat)
{
        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
        struct xfs_alloc_arg    args;           /* block allocation args */
        int                     error;          /* error return value */

        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);

        memset(&args, 0, sizeof(args));
        args.tp = cur->bc_tp;
        args.mp = cur->bc_mp;
        args.type = XFS_ALLOCTYPE_NEAR_BNO;
        args.fsbno = XFS_AGB_TO_FSB(cur->bc_mp, cur->bc_private.a.agno,
                        xfs_refc_block(args.mp));
        args.firstblock = args.fsbno;
        xfs_rmap_ag_owner(&args.oinfo, XFS_RMAP_OWN_REFC);
        args.minlen = args.maxlen = args.prod = 1;
        args.resv = XFS_AG_RESV_METADATA;

        error = xfs_alloc_vextent(&args);
        if (error)
                goto out_error;
        trace_xfs_refcountbt_alloc_block(cur->bc_mp, cur->bc_private.a.agno,
                        args.agbno, 1);
        if (args.fsbno == NULLFSBLOCK) {
                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
                *stat = 0;
                return 0;
        }
        ASSERT(args.agno == cur->bc_private.a.agno);
        ASSERT(args.len == 1);

        new->s = cpu_to_be32(args.agbno);
        be32_add_cpu(&agf->agf_refcount_blocks, 1);
        xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_REFCOUNT_BLOCKS);

        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
        *stat = 1;
        return 0;

out_error:
        XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
        return error;
}

STATIC int
xfs_refcountbt_free_block(
        struct xfs_btree_cur    *cur,
        struct xfs_buf          *bp)
{
        struct xfs_mount        *mp = cur->bc_mp;
        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
        xfs_fsblock_t           fsbno = XFS_DADDR_TO_FSB(mp, XFS_BUF_ADDR(bp));
        struct xfs_owner_info   oinfo;
        int                     error;

        trace_xfs_refcountbt_free_block(cur->bc_mp, cur->bc_private.a.agno,
                        XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno), 1);
        xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_REFC);
        be32_add_cpu(&agf->agf_refcount_blocks, -1);
        xfs_alloc_log_agf(cur->bc_tp, agbp, XFS_AGF_REFCOUNT_BLOCKS);
        error = xfs_free_extent(cur->bc_tp, fsbno, 1, &oinfo,
                        XFS_AG_RESV_METADATA);
        if (error)
                return error;

        return error;
}

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

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

STATIC void
xfs_refcountbt_init_key_from_rec(
        union xfs_btree_key     *key,
        union xfs_btree_rec     *rec)
{
        key->refc.rc_startblock = rec->refc.rc_startblock;
}

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

        x = be32_to_cpu(rec->refc.rc_startblock);
        x += be32_to_cpu(rec->refc.rc_blockcount) - 1;
        key->refc.rc_startblock = cpu_to_be32(x);
}

STATIC void
xfs_refcountbt_init_rec_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_rec     *rec)
{
        rec->refc.rc_startblock = cpu_to_be32(cur->bc_rec.rc.rc_startblock);
        rec->refc.rc_blockcount = cpu_to_be32(cur->bc_rec.rc.rc_blockcount);
        rec->refc.rc_refcount = cpu_to_be32(cur->bc_rec.rc.rc_refcount);
}

STATIC void
xfs_refcountbt_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_refcount_root != 0);

        ptr->s = agf->agf_refcount_root;
}

STATIC __int64_t
xfs_refcountbt_key_diff(
        struct xfs_btree_cur    *cur,
        union xfs_btree_key     *key)
{
        struct xfs_refcount_irec        *rec = &cur->bc_rec.rc;
        struct xfs_refcount_key         *kp = &key->refc;

        return (__int64_t)be32_to_cpu(kp->rc_startblock) - rec->rc_startblock;
}

STATIC __int64_t
xfs_refcountbt_diff_two_keys(
        struct xfs_btree_cur    *cur,
        union xfs_btree_key     *k1,
        union xfs_btree_key     *k2)
{
        return (__int64_t)be32_to_cpu(k1->refc.rc_startblock) -
                          be32_to_cpu(k2->refc.rc_startblock);
}

STATIC bool
xfs_refcountbt_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;

        if (block->bb_magic != cpu_to_be32(XFS_REFC_CRC_MAGIC))
                return false;

        if (!xfs_sb_version_hasreflink(&mp->m_sb))
                return false;
        if (!xfs_btree_sblock_v5hdr_verify(bp))
                return false;

        level = be16_to_cpu(block->bb_level);
        if (pag && pag->pagf_init) {
                if (level >= pag->pagf_refcount_level)
                        return false;
        } else if (level >= mp->m_refc_maxlevels)
                return false;

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

STATIC void
xfs_refcountbt_read_verify(
        struct xfs_buf  *bp)
{
        if (!xfs_btree_sblock_verify_crc(bp))
                xfs_buf_ioerror(bp, -EFSBADCRC);
        else if (!xfs_refcountbt_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_refcountbt_write_verify(
        struct xfs_buf  *bp)
{
        if (!xfs_refcountbt_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_refcountbt_buf_ops = {
        .name                   = "xfs_refcountbt",
        .verify_read            = xfs_refcountbt_read_verify,
        .verify_write           = xfs_refcountbt_write_verify,
};

#if defined(DEBUG) || defined(XFS_WARN)
STATIC int
xfs_refcountbt_keys_inorder(
        struct xfs_btree_cur    *cur,
        union xfs_btree_key     *k1,
        union xfs_btree_key     *k2)
{
        return be32_to_cpu(k1->refc.rc_startblock) <
               be32_to_cpu(k2->refc.rc_startblock);
}

STATIC int
xfs_refcountbt_recs_inorder(
        struct xfs_btree_cur    *cur,
        union xfs_btree_rec     *r1,
        union xfs_btree_rec     *r2)
{
        return  be32_to_cpu(r1->refc.rc_startblock) +
                be32_to_cpu(r1->refc.rc_blockcount) <=
                be32_to_cpu(r2->refc.rc_startblock);
}
#endif

static const struct xfs_btree_ops xfs_refcountbt_ops = {
        .rec_len                = sizeof(struct xfs_refcount_rec),
        .key_len                = sizeof(struct xfs_refcount_key),

        .dup_cursor             = xfs_refcountbt_dup_cursor,
        .set_root               = xfs_refcountbt_set_root,
        .alloc_block            = xfs_refcountbt_alloc_block,
        .free_block             = xfs_refcountbt_free_block,
        .get_minrecs            = xfs_refcountbt_get_minrecs,
        .get_maxrecs            = xfs_refcountbt_get_maxrecs,
        .init_key_from_rec      = xfs_refcountbt_init_key_from_rec,
        .init_high_key_from_rec = xfs_refcountbt_init_high_key_from_rec,
        .init_rec_from_cur      = xfs_refcountbt_init_rec_from_cur,
        .init_ptr_from_cur      = xfs_refcountbt_init_ptr_from_cur,
        .key_diff               = xfs_refcountbt_key_diff,
        .buf_ops                = &xfs_refcountbt_buf_ops,
        .diff_two_keys          = xfs_refcountbt_diff_two_keys,
#if defined(DEBUG) || defined(XFS_WARN)
        .keys_inorder           = xfs_refcountbt_keys_inorder,
        .recs_inorder           = xfs_refcountbt_recs_inorder,
#endif
};

/*
 * Allocate a new refcount btree cursor.
 */
struct xfs_btree_cur *
xfs_refcountbt_init_cursor(
        struct xfs_mount        *mp,
        struct xfs_trans        *tp,
        struct xfs_buf          *agbp,
        xfs_agnumber_t          agno,
        struct xfs_defer_ops    *dfops)
{
        struct xfs_agf          *agf = XFS_BUF_TO_AGF(agbp);
        struct xfs_btree_cur    *cur;

        ASSERT(agno != NULLAGNUMBER);
        ASSERT(agno < mp->m_sb.sb_agcount);
        cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_NOFS);

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

        cur->bc_nlevels = be32_to_cpu(agf->agf_refcount_level);

        cur->bc_private.a.agbp = agbp;
        cur->bc_private.a.agno = agno;
        cur->bc_private.a.dfops = dfops;
        cur->bc_flags |= XFS_BTREE_CRC_BLOCKS;

        cur->bc_private.a.priv.refc.nr_ops = 0;
        cur->bc_private.a.priv.refc.shape_changes = 0;

        return cur;
}

/*
 * Calculate the number of records in a refcount btree block.
 */
int
xfs_refcountbt_maxrecs(
        struct xfs_mount        *mp,
        int                     blocklen,
        bool                    leaf)
{
        blocklen -= XFS_REFCOUNT_BLOCK_LEN;

        if (leaf)
                return blocklen / sizeof(struct xfs_refcount_rec);
        return blocklen / (sizeof(struct xfs_refcount_key) +
                           sizeof(xfs_refcount_ptr_t));
}

/* Compute the maximum height of a refcount btree. */
void
xfs_refcountbt_compute_maxlevels(
        struct xfs_mount                *mp)
{
        mp->m_refc_maxlevels = xfs_btree_compute_maxlevels(mp,
                        mp->m_refc_mnr, mp->m_sb.sb_agblocks);
}

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

/*
 * Calculate the maximum refcount btree size.
 */
xfs_extlen_t
xfs_refcountbt_max_size(
        struct xfs_mount        *mp)
{
        /* Bail out if we're uninitialized, which can happen in mkfs. */
        if (mp->m_refc_mxr[0] == 0)
                return 0;

        return xfs_refcountbt_calc_size(mp, mp->m_sb.sb_agblocks);
}

/*
 * Figure out how many blocks to reserve and how many are used by this btree.
 */
int
xfs_refcountbt_calc_reserves(
        struct xfs_mount        *mp,
        xfs_agnumber_t          agno,
        xfs_extlen_t            *ask,
        xfs_extlen_t            *used)
{
        struct xfs_buf          *agbp;
        struct xfs_agf          *agf;
        xfs_extlen_t            tree_len;
        int                     error;

        if (!xfs_sb_version_hasreflink(&mp->m_sb))
                return 0;

        *ask += xfs_refcountbt_max_size(mp);

        error = xfs_alloc_read_agf(mp, NULL, agno, 0, &agbp);
        if (error)
                return error;

        agf = XFS_BUF_TO_AGF(agbp);
        tree_len = be32_to_cpu(agf->agf_refcount_blocks);
        xfs_buf_relse(agbp);

        *used += tree_len;

        return error;
}