xfs_alloc_btree.c

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/*
 * 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_types.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_alloc.h"
#include "xfs_extent_busy.h"
#include "xfs_error.h"
#include "xfs_trace.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         length,
    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);

    xfs_trans_binval(cur->bc_tp, bp);
    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;
}

#ifdef DEBUG
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,
#ifdef DEBUG
    .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;

    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));
}