/*
 * 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_bit.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_ialloc_btree.h"
#include "xfs_alloc.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_cksum.h"
#include "xfs_trans.h"


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

STATIC struct xfs_btree_cur *
xfs_inobt_dup_cursor(
        struct xfs_btree_cur    *cur)
{
        return xfs_inobt_init_cursor(cur->bc_mp, cur->bc_tp,
                        cur->bc_private.a.agbp, cur->bc_private.a.agno,
                        cur->bc_btnum);
}

STATIC void
xfs_inobt_set_root(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *nptr,
        int                     inc)    /* level change */
{
        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
        struct xfs_agi          *agi = XFS_BUF_TO_AGI(agbp);

        agi->agi_root = nptr->s;
        be32_add_cpu(&agi->agi_level, inc);
        xfs_ialloc_log_agi(cur->bc_tp, agbp, XFS_AGI_ROOT | XFS_AGI_LEVEL);
}

STATIC void
xfs_finobt_set_root(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *nptr,
        int                     inc)    /* level change */
{
        struct xfs_buf          *agbp = cur->bc_private.a.agbp;
        struct xfs_agi          *agi = XFS_BUF_TO_AGI(agbp);

        agi->agi_free_root = nptr->s;
        be32_add_cpu(&agi->agi_free_level, inc);
        xfs_ialloc_log_agi(cur->bc_tp, agbp,
                           XFS_AGI_FREE_ROOT | XFS_AGI_FREE_LEVEL);
}

STATIC int
xfs_inobt_alloc_block(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *start,
        union xfs_btree_ptr     *new,
        int                     *stat)
{
        xfs_alloc_arg_t         args;           /* block allocation args */
        int                     error;          /* error return value */
        xfs_agblock_t           sbno = be32_to_cpu(start->s);

        XFS_BTREE_TRACE_CURSOR(cur, XBT_ENTRY);

        memset(&args, 0, sizeof(args));
        args.tp = cur->bc_tp;
        args.mp = cur->bc_mp;
        args.fsbno = XFS_AGB_TO_FSB(args.mp, cur->bc_private.a.agno, sbno);
        args.minlen = 1;
        args.maxlen = 1;
        args.prod = 1;
        args.type = XFS_ALLOCTYPE_NEAR_BNO;

        error = xfs_alloc_vextent(&args);
        if (error) {
                XFS_BTREE_TRACE_CURSOR(cur, XBT_ERROR);
                return error;
        }
        if (args.fsbno == NULLFSBLOCK) {
                XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);
                *stat = 0;
                return 0;
        }
        ASSERT(args.len == 1);
        XFS_BTREE_TRACE_CURSOR(cur, XBT_EXIT);

        new->s = cpu_to_be32(XFS_FSB_TO_AGBNO(args.mp, args.fsbno));
        *stat = 1;
        return 0;
}

STATIC int
xfs_inobt_free_block(
        struct xfs_btree_cur    *cur,
        struct xfs_buf          *bp)
{
        return xfs_free_extent(cur->bc_tp,
                        XFS_DADDR_TO_FSB(cur->bc_mp, XFS_BUF_ADDR(bp)), 1);
}

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

STATIC void
xfs_inobt_init_key_from_rec(
        union xfs_btree_key     *key,
        union xfs_btree_rec     *rec)
{
        key->inobt.ir_startino = rec->inobt.ir_startino;
}

STATIC void
xfs_inobt_init_rec_from_key(
        union xfs_btree_key     *key,
        union xfs_btree_rec     *rec)
{
        rec->inobt.ir_startino = key->inobt.ir_startino;
}

STATIC void
xfs_inobt_init_rec_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_rec     *rec)
{
        rec->inobt.ir_startino = cpu_to_be32(cur->bc_rec.i.ir_startino);
        if (xfs_sb_version_hassparseinodes(&cur->bc_mp->m_sb)) {
                rec->inobt.ir_u.sp.ir_holemask =
                                        cpu_to_be16(cur->bc_rec.i.ir_holemask);
                rec->inobt.ir_u.sp.ir_count = cur->bc_rec.i.ir_count;
                rec->inobt.ir_u.sp.ir_freecount = cur->bc_rec.i.ir_freecount;
        } else {
                /* ir_holemask/ir_count not supported on-disk */
                rec->inobt.ir_u.f.ir_freecount =
                                        cpu_to_be32(cur->bc_rec.i.ir_freecount);
        }
        rec->inobt.ir_free = cpu_to_be64(cur->bc_rec.i.ir_free);
}

/*
 * initial value of ptr for lookup
 */
STATIC void
xfs_inobt_init_ptr_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *ptr)
{
        struct xfs_agi          *agi = XFS_BUF_TO_AGI(cur->bc_private.a.agbp);

        ASSERT(cur->bc_private.a.agno == be32_to_cpu(agi->agi_seqno));

        ptr->s = agi->agi_root;
}

STATIC void
xfs_finobt_init_ptr_from_cur(
        struct xfs_btree_cur    *cur,
        union xfs_btree_ptr     *ptr)
{
        struct xfs_agi          *agi = XFS_BUF_TO_AGI(cur->bc_private.a.agbp);

        ASSERT(cur->bc_private.a.agno == be32_to_cpu(agi->agi_seqno));
        ptr->s = agi->agi_free_root;
}

STATIC __int64_t
xfs_inobt_key_diff(
        struct xfs_btree_cur    *cur,
        union xfs_btree_key     *key)
{
        return (__int64_t)be32_to_cpu(key->inobt.ir_startino) -
                          cur->bc_rec.i.ir_startino;
}

static int
xfs_inobt_verify(
        struct xfs_buf          *bp)
{
        struct xfs_mount        *mp = bp->b_target->bt_mount;
        struct xfs_btree_block  *block = XFS_BUF_TO_BLOCK(bp);
        unsigned int            level;

        /*
         * During growfs operations, we can't verify the exact owner as the
         * perag is not fully initialised and hence not attached to the buffer.
         *
         * Similarly, during log recovery we will have a perag structure
         * attached, but the agi information will not yet have been initialised
         * from the on disk AGI. We don't currently use any of this information,
         * but beware of the landmine (i.e. need to check pag->pagi_init) if we
         * ever do.
         */
        switch (block->bb_magic) {
        case cpu_to_be32(XFS_IBT_CRC_MAGIC):
        case cpu_to_be32(XFS_FIBT_CRC_MAGIC):
                if (!xfs_btree_sblock_v5hdr_verify(bp))
                        return false;
                /* fall through */
        case cpu_to_be32(XFS_IBT_MAGIC):
        case cpu_to_be32(XFS_FIBT_MAGIC):
                break;
        default:
                return 0;
        }

        /* level verification */
        level = be16_to_cpu(block->bb_level);
        if (level >= mp->m_in_maxlevels)
                return false;

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

static void
xfs_inobt_read_verify(
        struct xfs_buf  *bp)
{
        if (!xfs_btree_sblock_verify_crc(bp))
                xfs_buf_ioerror(bp, -EFSBADCRC);
        else if (!xfs_inobt_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_inobt_write_verify(
        struct xfs_buf  *bp)
{
        if (!xfs_inobt_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_inobt_buf_ops = {
        .name = "xfs_inobt",
        .verify_read = xfs_inobt_read_verify,
        .verify_write = xfs_inobt_write_verify,
};

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

STATIC int
xfs_inobt_recs_inorder(
        struct xfs_btree_cur    *cur,
        union xfs_btree_rec     *r1,
        union xfs_btree_rec     *r2)
{
        return be32_to_cpu(r1->inobt.ir_startino) + XFS_INODES_PER_CHUNK <=
                be32_to_cpu(r2->inobt.ir_startino);
}
#endif  /* DEBUG */

static const struct xfs_btree_ops xfs_inobt_ops = {
        .rec_len                = sizeof(xfs_inobt_rec_t),
        .key_len                = sizeof(xfs_inobt_key_t),

        .dup_cursor             = xfs_inobt_dup_cursor,
        .set_root               = xfs_inobt_set_root,
        .alloc_block            = xfs_inobt_alloc_block,
        .free_block             = xfs_inobt_free_block,
        .get_minrecs            = xfs_inobt_get_minrecs,
        .get_maxrecs            = xfs_inobt_get_maxrecs,
        .init_key_from_rec      = xfs_inobt_init_key_from_rec,
        .init_rec_from_key      = xfs_inobt_init_rec_from_key,
        .init_rec_from_cur      = xfs_inobt_init_rec_from_cur,
        .init_ptr_from_cur      = xfs_inobt_init_ptr_from_cur,
        .key_diff               = xfs_inobt_key_diff,
        .buf_ops                = &xfs_inobt_buf_ops,
#if defined(DEBUG) || defined(XFS_WARN)
        .keys_inorder           = xfs_inobt_keys_inorder,
        .recs_inorder           = xfs_inobt_recs_inorder,
#endif
};

static const struct xfs_btree_ops xfs_finobt_ops = {
        .rec_len                = sizeof(xfs_inobt_rec_t),
        .key_len                = sizeof(xfs_inobt_key_t),

        .dup_cursor             = xfs_inobt_dup_cursor,
        .set_root               = xfs_finobt_set_root,
        .alloc_block            = xfs_inobt_alloc_block,
        .free_block             = xfs_inobt_free_block,
        .get_minrecs            = xfs_inobt_get_minrecs,
        .get_maxrecs            = xfs_inobt_get_maxrecs,
        .init_key_from_rec      = xfs_inobt_init_key_from_rec,
        .init_rec_from_key      = xfs_inobt_init_rec_from_key,
        .init_rec_from_cur      = xfs_inobt_init_rec_from_cur,
        .init_ptr_from_cur      = xfs_finobt_init_ptr_from_cur,
        .key_diff               = xfs_inobt_key_diff,
        .buf_ops                = &xfs_inobt_buf_ops,
#if defined(DEBUG) || defined(XFS_WARN)
        .keys_inorder           = xfs_inobt_keys_inorder,
        .recs_inorder           = xfs_inobt_recs_inorder,
#endif
};

/*
 * Allocate a new inode btree cursor.
 */
struct xfs_btree_cur *                          /* new inode btree cursor */
xfs_inobt_init_cursor(
        struct xfs_mount        *mp,            /* file system mount point */
        struct xfs_trans        *tp,            /* transaction pointer */
        struct xfs_buf          *agbp,          /* buffer for agi structure */
        xfs_agnumber_t          agno,           /* allocation group number */
        xfs_btnum_t             btnum)          /* ialloc or free ino btree */
{
        struct xfs_agi          *agi = XFS_BUF_TO_AGI(agbp);
        struct xfs_btree_cur    *cur;

        cur = kmem_zone_zalloc(xfs_btree_cur_zone, KM_SLEEP);

        cur->bc_tp = tp;
        cur->bc_mp = mp;
        cur->bc_btnum = btnum;
        if (btnum == XFS_BTNUM_INO) {
                cur->bc_nlevels = be32_to_cpu(agi->agi_level);
                cur->bc_ops = &xfs_inobt_ops;
        } else {
                cur->bc_nlevels = be32_to_cpu(agi->agi_free_level);
                cur->bc_ops = &xfs_finobt_ops;
        }

        cur->bc_blocklog = mp->m_sb.sb_blocklog;

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

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

        return cur;
}

/*
 * Calculate number of records in an inobt btree block.
 */
int
xfs_inobt_maxrecs(
        struct xfs_mount        *mp,
        int                     blocklen,
        int                     leaf)
{
        blocklen -= XFS_INOBT_BLOCK_LEN(mp);

        if (leaf)
                return blocklen / sizeof(xfs_inobt_rec_t);
        return blocklen / (sizeof(xfs_inobt_key_t) + sizeof(xfs_inobt_ptr_t));
}

/*
 * Convert the inode record holemask to an inode allocation bitmap. The inode
 * allocation bitmap is inode granularity and specifies whether an inode is
 * physically allocated on disk (not whether the inode is considered allocated
 * or free by the fs).
 *
 * A bit value of 1 means the inode is allocated, a value of 0 means it is free.
 */
uint64_t
xfs_inobt_irec_to_allocmask(
        struct xfs_inobt_rec_incore     *rec)
{
        uint64_t                        bitmap = 0;
        uint64_t                        inodespbit;
        int                             nextbit;
        uint                            allocbitmap;

        /*
         * The holemask has 16-bits for a 64 inode record. Therefore each
         * holemask bit represents multiple inodes. Create a mask of bits to set
         * in the allocmask for each holemask bit.
         */
        inodespbit = (1 << XFS_INODES_PER_HOLEMASK_BIT) - 1;

        /*
         * Allocated inodes are represented by 0 bits in holemask. Invert the 0
         * bits to 1 and convert to a uint so we can use xfs_next_bit(). Mask
         * anything beyond the 16 holemask bits since this casts to a larger
         * type.
         */
        allocbitmap = ~rec->ir_holemask & ((1 << XFS_INOBT_HOLEMASK_BITS) - 1);

        /*
         * allocbitmap is the inverted holemask so every set bit represents
         * allocated inodes. To expand from 16-bit holemask granularity to
         * 64-bit (e.g., bit-per-inode), set inodespbit bits in the target
         * bitmap for every holemask bit.
         */
        nextbit = xfs_next_bit(&allocbitmap, 1, 0);
        while (nextbit != -1) {
                ASSERT(nextbit < (sizeof(rec->ir_holemask) * NBBY));

                bitmap |= (inodespbit <<
                           (nextbit * XFS_INODES_PER_HOLEMASK_BIT));

                nextbit = xfs_next_bit(&allocbitmap, 1, nextbit + 1);
        }

        return bitmap;
}

#if defined(DEBUG) || defined(XFS_WARN)
/*
 * Verify that an in-core inode record has a valid inode count.
 */
int
xfs_inobt_rec_check_count(
        struct xfs_mount                *mp,
        struct xfs_inobt_rec_incore     *rec)
{
        int                             inocount = 0;
        int                             nextbit = 0;
        uint64_t                        allocbmap;
        int                             wordsz;

        wordsz = sizeof(allocbmap) / sizeof(unsigned int);
        allocbmap = xfs_inobt_irec_to_allocmask(rec);

        nextbit = xfs_next_bit((uint *) &allocbmap, wordsz, nextbit);
        while (nextbit != -1) {
                inocount++;
                nextbit = xfs_next_bit((uint *) &allocbmap, wordsz,
                                       nextbit + 1);
        }

        if (inocount != rec->ir_count)
                return -EFSCORRUPTED;

        return 0;
}
#endif  /* DEBUG */