/*
 * Copyright (c) 2000-2005 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_defer.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_error.h"
#include "xfs_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_alloc.h"
#include "xfs_rmap_btree.h"
#include "xfs_ialloc.h"
#include "xfs_fsops.h"
#include "xfs_itable.h"
#include "xfs_trans_space.h"
#include "xfs_rtalloc.h"
#include "xfs_trace.h"
#include "xfs_log.h"
#include "xfs_filestream.h"
#include "xfs_rmap.h"
#include "xfs_ag_resv.h"

/*
 * File system operations
 */

static struct xfs_buf *
xfs_growfs_get_hdr_buf(
        struct xfs_mount        *mp,
        xfs_daddr_t             blkno,
        size_t                  numblks,
        int                     flags,
        const struct xfs_buf_ops *ops)
{
        struct xfs_buf          *bp;

        bp = xfs_buf_get_uncached(mp->m_ddev_targp, numblks, flags);
        if (!bp)
                return NULL;

        xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
        bp->b_bn = blkno;
        bp->b_maps[0].bm_bn = blkno;
        bp->b_ops = ops;

        return bp;
}

static int
xfs_growfs_data_private(
        xfs_mount_t             *mp,            /* mount point for filesystem */
        xfs_growfs_data_t       *in)            /* growfs data input struct */
{
        xfs_agf_t               *agf;
        struct xfs_agfl         *agfl;
        xfs_agi_t               *agi;
        xfs_agnumber_t          agno;
        xfs_extlen_t            agsize;
        xfs_extlen_t            tmpsize;
        xfs_alloc_rec_t         *arec;
        xfs_buf_t               *bp;
        int                     bucket;
        int                     dpct;
        int                     error, saved_error = 0;
        xfs_agnumber_t          nagcount;
        xfs_agnumber_t          nagimax = 0;
        xfs_rfsblock_t          nb, nb_mod;
        xfs_rfsblock_t          new;
        xfs_rfsblock_t          nfree;
        xfs_agnumber_t          oagcount;
        int                     pct;
        xfs_trans_t             *tp;

        nb = in->newblocks;
        pct = in->imaxpct;
        if (nb < mp->m_sb.sb_dblocks || pct < 0 || pct > 100)
                return -EINVAL;
        if ((error = xfs_sb_validate_fsb_count(&mp->m_sb, nb)))
                return error;
        dpct = pct - mp->m_sb.sb_imax_pct;
        error = xfs_buf_read_uncached(mp->m_ddev_targp,
                                XFS_FSB_TO_BB(mp, nb) - XFS_FSS_TO_BB(mp, 1),
                                XFS_FSS_TO_BB(mp, 1), 0, &bp, NULL);
        if (error)
                return error;
        xfs_buf_relse(bp);

        new = nb;       /* use new as a temporary here */
        nb_mod = do_div(new, mp->m_sb.sb_agblocks);
        nagcount = new + (nb_mod != 0);
        if (nb_mod && nb_mod < XFS_MIN_AG_BLOCKS) {
                nagcount--;
                nb = (xfs_rfsblock_t)nagcount * mp->m_sb.sb_agblocks;
                if (nb < mp->m_sb.sb_dblocks)
                        return -EINVAL;
        }
        new = nb - mp->m_sb.sb_dblocks;
        oagcount = mp->m_sb.sb_agcount;

        /* allocate the new per-ag structures */
        if (nagcount > oagcount) {
                error = xfs_initialize_perag(mp, nagcount, &nagimax);
                if (error)
                        return error;
        }

        error = xfs_trans_alloc(mp, &M_RES(mp)->tr_growdata,
                        XFS_GROWFS_SPACE_RES(mp), 0, XFS_TRANS_RESERVE, &tp);
        if (error)
                return error;

        /*
         * Write new AG headers to disk. Non-transactional, but written
         * synchronously so they are completed prior to the growfs transaction
         * being logged.
         */
        nfree = 0;
        for (agno = nagcount - 1; agno >= oagcount; agno--, new -= agsize) {
                __be32  *agfl_bno;

                /*
                 * AG freespace header block
                 */
                bp = xfs_growfs_get_hdr_buf(mp,
                                XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
                                XFS_FSS_TO_BB(mp, 1), 0,
                                &xfs_agf_buf_ops);
                if (!bp) {
                        error = -ENOMEM;
                        goto error0;
                }

                agf = XFS_BUF_TO_AGF(bp);
                agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
                agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
                agf->agf_seqno = cpu_to_be32(agno);
                if (agno == nagcount - 1)
                        agsize =
                                nb -
                                (agno * (xfs_rfsblock_t)mp->m_sb.sb_agblocks);
                else
                        agsize = mp->m_sb.sb_agblocks;
                agf->agf_length = cpu_to_be32(agsize);
                agf->agf_roots[XFS_BTNUM_BNOi] = cpu_to_be32(XFS_BNO_BLOCK(mp));
                agf->agf_roots[XFS_BTNUM_CNTi] = cpu_to_be32(XFS_CNT_BLOCK(mp));
                agf->agf_levels[XFS_BTNUM_BNOi] = cpu_to_be32(1);
                agf->agf_levels[XFS_BTNUM_CNTi] = cpu_to_be32(1);
                if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
                        agf->agf_roots[XFS_BTNUM_RMAPi] =
                                                cpu_to_be32(XFS_RMAP_BLOCK(mp));
                        agf->agf_levels[XFS_BTNUM_RMAPi] = cpu_to_be32(1);
                        agf->agf_rmap_blocks = cpu_to_be32(1);
                }

                agf->agf_flfirst = cpu_to_be32(1);
                agf->agf_fllast = 0;
                agf->agf_flcount = 0;
                tmpsize = agsize - mp->m_ag_prealloc_blocks;
                agf->agf_freeblks = cpu_to_be32(tmpsize);
                agf->agf_longest = cpu_to_be32(tmpsize);
                if (xfs_sb_version_hascrc(&mp->m_sb))
                        uuid_copy(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid);
                if (xfs_sb_version_hasreflink(&mp->m_sb)) {
                        agf->agf_refcount_root = cpu_to_be32(
                                        xfs_refc_block(mp));
                        agf->agf_refcount_level = cpu_to_be32(1);
                        agf->agf_refcount_blocks = cpu_to_be32(1);
                }

                error = xfs_bwrite(bp);
                xfs_buf_relse(bp);
                if (error)
                        goto error0;

                /*
                 * AG freelist header block
                 */
                bp = xfs_growfs_get_hdr_buf(mp,
                                XFS_AG_DADDR(mp, agno, XFS_AGFL_DADDR(mp)),
                                XFS_FSS_TO_BB(mp, 1), 0,
                                &xfs_agfl_buf_ops);
                if (!bp) {
                        error = -ENOMEM;
                        goto error0;
                }

                agfl = XFS_BUF_TO_AGFL(bp);
                if (xfs_sb_version_hascrc(&mp->m_sb)) {
                        agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC);
                        agfl->agfl_seqno = cpu_to_be32(agno);
                        uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid);
                }

                agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, bp);
                for (bucket = 0; bucket < XFS_AGFL_SIZE(mp); bucket++)
                        agfl_bno[bucket] = cpu_to_be32(NULLAGBLOCK);

                error = xfs_bwrite(bp);
                xfs_buf_relse(bp);
                if (error)
                        goto error0;

                /*
                 * AG inode header block
                 */
                bp = xfs_growfs_get_hdr_buf(mp,
                                XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
                                XFS_FSS_TO_BB(mp, 1), 0,
                                &xfs_agi_buf_ops);
                if (!bp) {
                        error = -ENOMEM;
                        goto error0;
                }

                agi = XFS_BUF_TO_AGI(bp);
                agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
                agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
                agi->agi_seqno = cpu_to_be32(agno);
                agi->agi_length = cpu_to_be32(agsize);
                agi->agi_count = 0;
                agi->agi_root = cpu_to_be32(XFS_IBT_BLOCK(mp));
                agi->agi_level = cpu_to_be32(1);
                agi->agi_freecount = 0;
                agi->agi_newino = cpu_to_be32(NULLAGINO);
                agi->agi_dirino = cpu_to_be32(NULLAGINO);
                if (xfs_sb_version_hascrc(&mp->m_sb))
                        uuid_copy(&agi->agi_uuid, &mp->m_sb.sb_meta_uuid);
                if (xfs_sb_version_hasfinobt(&mp->m_sb)) {
                        agi->agi_free_root = cpu_to_be32(XFS_FIBT_BLOCK(mp));
                        agi->agi_free_level = cpu_to_be32(1);
                }
                for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++)
                        agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);

                error = xfs_bwrite(bp);
                xfs_buf_relse(bp);
                if (error)
                        goto error0;

                /*
                 * BNO btree root block
                 */
                bp = xfs_growfs_get_hdr_buf(mp,
                                XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
                                BTOBB(mp->m_sb.sb_blocksize), 0,
                                &xfs_allocbt_buf_ops);

                if (!bp) {
                        error = -ENOMEM;
                        goto error0;
                }

                xfs_btree_init_block(mp, bp, XFS_BTNUM_BNO, 0, 1, agno, 0);

                arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
                arec->ar_startblock = cpu_to_be32(mp->m_ag_prealloc_blocks);
                arec->ar_blockcount = cpu_to_be32(
                        agsize - be32_to_cpu(arec->ar_startblock));

                error = xfs_bwrite(bp);
                xfs_buf_relse(bp);
                if (error)
                        goto error0;

                /*
                 * CNT btree root block
                 */
                bp = xfs_growfs_get_hdr_buf(mp,
                                XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
                                BTOBB(mp->m_sb.sb_blocksize), 0,
                                &xfs_allocbt_buf_ops);
                if (!bp) {
                        error = -ENOMEM;
                        goto error0;
                }

                xfs_btree_init_block(mp, bp, XFS_BTNUM_CNT, 0, 1, agno, 0);

                arec = XFS_ALLOC_REC_ADDR(mp, XFS_BUF_TO_BLOCK(bp), 1);
                arec->ar_startblock = cpu_to_be32(mp->m_ag_prealloc_blocks);
                arec->ar_blockcount = cpu_to_be32(
                        agsize - be32_to_cpu(arec->ar_startblock));
                nfree += be32_to_cpu(arec->ar_blockcount);

                error = xfs_bwrite(bp);
                xfs_buf_relse(bp);
                if (error)
                        goto error0;

                /* RMAP btree root block */
                if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
                        struct xfs_rmap_rec     *rrec;
                        struct xfs_btree_block  *block;

                        bp = xfs_growfs_get_hdr_buf(mp,
                                XFS_AGB_TO_DADDR(mp, agno, XFS_RMAP_BLOCK(mp)),
                                BTOBB(mp->m_sb.sb_blocksize), 0,
                                &xfs_rmapbt_buf_ops);
                        if (!bp) {
                                error = -ENOMEM;
                                goto error0;
                        }

                        xfs_btree_init_block(mp, bp, XFS_BTNUM_RMAP, 0, 0,
                                                agno, 0);
                        block = XFS_BUF_TO_BLOCK(bp);


                        /*
                         * mark the AG header regions as static metadata The BNO
                         * btree block is the first block after the headers, so
                         * it's location defines the size of region the static
                         * metadata consumes.
                         *
                         * Note: unlike mkfs, we never have to account for log
                         * space when growing the data regions
                         */
                        rrec = XFS_RMAP_REC_ADDR(block, 1);
                        rrec->rm_startblock = 0;
                        rrec->rm_blockcount = cpu_to_be32(XFS_BNO_BLOCK(mp));
                        rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_FS);
                        rrec->rm_offset = 0;
                        be16_add_cpu(&block->bb_numrecs, 1);

                        /* account freespace btree root blocks */
                        rrec = XFS_RMAP_REC_ADDR(block, 2);
                        rrec->rm_startblock = cpu_to_be32(XFS_BNO_BLOCK(mp));
                        rrec->rm_blockcount = cpu_to_be32(2);
                        rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_AG);
                        rrec->rm_offset = 0;
                        be16_add_cpu(&block->bb_numrecs, 1);

                        /* account inode btree root blocks */
                        rrec = XFS_RMAP_REC_ADDR(block, 3);
                        rrec->rm_startblock = cpu_to_be32(XFS_IBT_BLOCK(mp));
                        rrec->rm_blockcount = cpu_to_be32(XFS_RMAP_BLOCK(mp) -
                                                        XFS_IBT_BLOCK(mp));
                        rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_INOBT);
                        rrec->rm_offset = 0;
                        be16_add_cpu(&block->bb_numrecs, 1);

                        /* account for rmap btree root */
                        rrec = XFS_RMAP_REC_ADDR(block, 4);
                        rrec->rm_startblock = cpu_to_be32(XFS_RMAP_BLOCK(mp));
                        rrec->rm_blockcount = cpu_to_be32(1);
                        rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_AG);
                        rrec->rm_offset = 0;
                        be16_add_cpu(&block->bb_numrecs, 1);

                        /* account for refc btree root */
                        if (xfs_sb_version_hasreflink(&mp->m_sb)) {
                                rrec = XFS_RMAP_REC_ADDR(block, 5);
                                rrec->rm_startblock = cpu_to_be32(
                                                xfs_refc_block(mp));
                                rrec->rm_blockcount = cpu_to_be32(1);
                                rrec->rm_owner = cpu_to_be64(XFS_RMAP_OWN_REFC);
                                rrec->rm_offset = 0;
                                be16_add_cpu(&block->bb_numrecs, 1);
                        }

                        error = xfs_bwrite(bp);
                        xfs_buf_relse(bp);
                        if (error)
                                goto error0;
                }

                /*
                 * INO btree root block
                 */
                bp = xfs_growfs_get_hdr_buf(mp,
                                XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
                                BTOBB(mp->m_sb.sb_blocksize), 0,
                                &xfs_inobt_buf_ops);
                if (!bp) {
                        error = -ENOMEM;
                        goto error0;
                }

                xfs_btree_init_block(mp, bp, XFS_BTNUM_INO , 0, 0, agno, 0);

                error = xfs_bwrite(bp);
                xfs_buf_relse(bp);
                if (error)
                        goto error0;

                /*
                 * FINO btree root block
                 */
                if (xfs_sb_version_hasfinobt(&mp->m_sb)) {
                        bp = xfs_growfs_get_hdr_buf(mp,
                                XFS_AGB_TO_DADDR(mp, agno, XFS_FIBT_BLOCK(mp)),
                                BTOBB(mp->m_sb.sb_blocksize), 0,
                                &xfs_inobt_buf_ops);
                        if (!bp) {
                                error = -ENOMEM;
                                goto error0;
                        }

                        xfs_btree_init_block(mp, bp, XFS_BTNUM_FINO,
                                                     0, 0, agno, 0);

                        error = xfs_bwrite(bp);
                        xfs_buf_relse(bp);
                        if (error)
                                goto error0;
                }

                /*
                 * refcount btree root block
                 */
                if (xfs_sb_version_hasreflink(&mp->m_sb)) {
                        bp = xfs_growfs_get_hdr_buf(mp,
                                XFS_AGB_TO_DADDR(mp, agno, xfs_refc_block(mp)),
                                BTOBB(mp->m_sb.sb_blocksize), 0,
                                &xfs_refcountbt_buf_ops);
                        if (!bp) {
                                error = -ENOMEM;
                                goto error0;
                        }

                        xfs_btree_init_block(mp, bp, XFS_BTNUM_REFC,
                                             0, 0, agno, 0);

                        error = xfs_bwrite(bp);
                        xfs_buf_relse(bp);
                        if (error)
                                goto error0;
                }
        }
        xfs_trans_agblocks_delta(tp, nfree);
        /*
         * There are new blocks in the old last a.g.
         */
        if (new) {
                struct xfs_owner_info   oinfo;

                /*
                 * Change the agi length.
                 */
                error = xfs_ialloc_read_agi(mp, tp, agno, &bp);
                if (error) {
                        goto error0;
                }
                ASSERT(bp);
                agi = XFS_BUF_TO_AGI(bp);
                be32_add_cpu(&agi->agi_length, new);
                ASSERT(nagcount == oagcount ||
                       be32_to_cpu(agi->agi_length) == mp->m_sb.sb_agblocks);
                xfs_ialloc_log_agi(tp, bp, XFS_AGI_LENGTH);
                /*
                 * Change agf length.
                 */
                error = xfs_alloc_read_agf(mp, tp, agno, 0, &bp);
                if (error) {
                        goto error0;
                }
                ASSERT(bp);
                agf = XFS_BUF_TO_AGF(bp);
                be32_add_cpu(&agf->agf_length, new);
                ASSERT(be32_to_cpu(agf->agf_length) ==
                       be32_to_cpu(agi->agi_length));

                xfs_alloc_log_agf(tp, bp, XFS_AGF_LENGTH);

                /*
                 * Free the new space.
                 *
                 * XFS_RMAP_OWN_NULL is used here to tell the rmap btree that
                 * this doesn't actually exist in the rmap btree.
                 */
                xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_NULL);
                error = xfs_rmap_free(tp, bp, agno,
                                be32_to_cpu(agf->agf_length) - new,
                                new, &oinfo);
                if (error)
                        goto error0;
                error = xfs_free_extent(tp,
                                XFS_AGB_TO_FSB(mp, agno,
                                        be32_to_cpu(agf->agf_length) - new),
                                new, &oinfo, XFS_AG_RESV_NONE);
                if (error)
                        goto error0;
        }

        /*
         * Update changed superblock fields transactionally. These are not
         * seen by the rest of the world until the transaction commit applies
         * them atomically to the superblock.
         */
        if (nagcount > oagcount)
                xfs_trans_mod_sb(tp, XFS_TRANS_SB_AGCOUNT, nagcount - oagcount);
        if (nb > mp->m_sb.sb_dblocks)
                xfs_trans_mod_sb(tp, XFS_TRANS_SB_DBLOCKS,
                                 nb - mp->m_sb.sb_dblocks);
        if (nfree)
                xfs_trans_mod_sb(tp, XFS_TRANS_SB_FDBLOCKS, nfree);
        if (dpct)
                xfs_trans_mod_sb(tp, XFS_TRANS_SB_IMAXPCT, dpct);
        xfs_trans_set_sync(tp);
        error = xfs_trans_commit(tp);
        if (error)
                return error;

        /* New allocation groups fully initialized, so update mount struct */
        if (nagimax)
                mp->m_maxagi = nagimax;
        if (mp->m_sb.sb_imax_pct) {
                uint64_t icount = mp->m_sb.sb_dblocks * mp->m_sb.sb_imax_pct;
                do_div(icount, 100);
                mp->m_maxicount = icount << mp->m_sb.sb_inopblog;
        } else
                mp->m_maxicount = 0;
        xfs_set_low_space_thresholds(mp);
        mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);

        /*
         * If we expanded the last AG, free the per-AG reservation
         * so we can reinitialize it with the new size.
         */
        if (new) {
                struct xfs_perag        *pag;

                pag = xfs_perag_get(mp, agno);
                error = xfs_ag_resv_free(pag);
                xfs_perag_put(pag);
                if (error)
                        goto out;
        }

        /* Reserve AG metadata blocks. */
        error = xfs_fs_reserve_ag_blocks(mp);
        if (error && error != -ENOSPC)
                goto out;

        /* update secondary superblocks. */
        for (agno = 1; agno < nagcount; agno++) {
                error = 0;
                /*
                 * new secondary superblocks need to be zeroed, not read from
                 * disk as the contents of the new area we are growing into is
                 * completely unknown.
                 */
                if (agno < oagcount) {
                        error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp,
                                  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
                                  XFS_FSS_TO_BB(mp, 1), 0, &bp,
                                  &xfs_sb_buf_ops);
                } else {
                        bp = xfs_trans_get_buf(NULL, mp->m_ddev_targp,
                                  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
                                  XFS_FSS_TO_BB(mp, 1), 0);
                        if (bp) {
                                bp->b_ops = &xfs_sb_buf_ops;
                                xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
                        } else
                                error = -ENOMEM;
                }

                /*
                 * If we get an error reading or writing alternate superblocks,
                 * continue.  xfs_repair chooses the "best" superblock based
                 * on most matches; if we break early, we'll leave more
                 * superblocks un-updated than updated, and xfs_repair may
                 * pick them over the properly-updated primary.
                 */
                if (error) {
                        xfs_warn(mp,
                "error %d reading secondary superblock for ag %d",
                                error, agno);
                        saved_error = error;
                        continue;
                }
                xfs_sb_to_disk(XFS_BUF_TO_SBP(bp), &mp->m_sb);

                error = xfs_bwrite(bp);
                xfs_buf_relse(bp);
                if (error) {
                        xfs_warn(mp,
                "write error %d updating secondary superblock for ag %d",
                                error, agno);
                        saved_error = error;
                        continue;
                }
        }

 out:
        return saved_error ? saved_error : error;

 error0:
        xfs_trans_cancel(tp);
        return error;
}

static int
xfs_growfs_log_private(
        xfs_mount_t             *mp,    /* mount point for filesystem */
        xfs_growfs_log_t        *in)    /* growfs log input struct */
{
        xfs_extlen_t            nb;

        nb = in->newblocks;
        if (nb < XFS_MIN_LOG_BLOCKS || nb < XFS_B_TO_FSB(mp, XFS_MIN_LOG_BYTES))
                return -EINVAL;
        if (nb == mp->m_sb.sb_logblocks &&
            in->isint == (mp->m_sb.sb_logstart != 0))
                return -EINVAL;
        /*
         * Moving the log is hard, need new interfaces to sync
         * the log first, hold off all activity while moving it.
         * Can have shorter or longer log in the same space,
         * or transform internal to external log or vice versa.
         */
        return -ENOSYS;
}

/*
 * protected versions of growfs function acquire and release locks on the mount
 * point - exported through ioctls: XFS_IOC_FSGROWFSDATA, XFS_IOC_FSGROWFSLOG,
 * XFS_IOC_FSGROWFSRT
 */


int
xfs_growfs_data(
        xfs_mount_t             *mp,
        xfs_growfs_data_t       *in)
{
        int error;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
        if (!mutex_trylock(&mp->m_growlock))
                return -EWOULDBLOCK;
        error = xfs_growfs_data_private(mp, in);
        /*
         * Increment the generation unconditionally, the error could be from
         * updating the secondary superblocks, in which case the new size
         * is live already.
         */
        mp->m_generation++;
        mutex_unlock(&mp->m_growlock);
        return error;
}

int
xfs_growfs_log(
        xfs_mount_t             *mp,
        xfs_growfs_log_t        *in)
{
        int error;

        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
        if (!mutex_trylock(&mp->m_growlock))
                return -EWOULDBLOCK;
        error = xfs_growfs_log_private(mp, in);
        mutex_unlock(&mp->m_growlock);
        return error;
}

/*
 * exported through ioctl XFS_IOC_FSCOUNTS
 */

int
xfs_fs_counts(
        xfs_mount_t             *mp,
        xfs_fsop_counts_t       *cnt)
{
        cnt->allocino = percpu_counter_read_positive(&mp->m_icount);
        cnt->freeino = percpu_counter_read_positive(&mp->m_ifree);
        cnt->freedata = percpu_counter_read_positive(&mp->m_fdblocks) -
                                                mp->m_alloc_set_aside;

        spin_lock(&mp->m_sb_lock);
        cnt->freertx = mp->m_sb.sb_frextents;
        spin_unlock(&mp->m_sb_lock);
        return 0;
}

/*
 * exported through ioctl XFS_IOC_SET_RESBLKS & XFS_IOC_GET_RESBLKS
 *
 * xfs_reserve_blocks is called to set m_resblks
 * in the in-core mount table. The number of unused reserved blocks
 * is kept in m_resblks_avail.
 *
 * Reserve the requested number of blocks if available. Otherwise return
 * as many as possible to satisfy the request. The actual number
 * reserved are returned in outval
 *
 * A null inval pointer indicates that only the current reserved blocks
 * available  should  be returned no settings are changed.
 */

int
xfs_reserve_blocks(
        xfs_mount_t             *mp,
        uint64_t              *inval,
        xfs_fsop_resblks_t      *outval)
{
        int64_t                 lcounter, delta;
        int64_t                 fdblks_delta = 0;
        uint64_t                request;
        int64_t                 free;
        int                     error = 0;

        /* If inval is null, report current values and return */
        if (inval == (uint64_t *)NULL) {
                if (!outval)
                        return -EINVAL;
                outval->resblks = mp->m_resblks;
                outval->resblks_avail = mp->m_resblks_avail;
                return 0;
        }

        request = *inval;

        /*
         * With per-cpu counters, this becomes an interesting problem. we need
         * to work out if we are freeing or allocation blocks first, then we can
         * do the modification as necessary.
         *
         * We do this under the m_sb_lock so that if we are near ENOSPC, we will
         * hold out any changes while we work out what to do. This means that
         * the amount of free space can change while we do this, so we need to
         * retry if we end up trying to reserve more space than is available.
         */
        spin_lock(&mp->m_sb_lock);

        /*
         * If our previous reservation was larger than the current value,
         * then move any unused blocks back to the free pool. Modify the resblks
         * counters directly since we shouldn't have any problems unreserving
         * space.
         */
        if (mp->m_resblks > request) {
                lcounter = mp->m_resblks_avail - request;
                if (lcounter  > 0) {            /* release unused blocks */
                        fdblks_delta = lcounter;
                        mp->m_resblks_avail -= lcounter;
                }
                mp->m_resblks = request;
                if (fdblks_delta) {
                        spin_unlock(&mp->m_sb_lock);
                        error = xfs_mod_fdblocks(mp, fdblks_delta, 0);
                        spin_lock(&mp->m_sb_lock);
                }

                goto out;
        }

        /*
         * If the request is larger than the current reservation, reserve the
         * blocks before we update the reserve counters. Sample m_fdblocks and
         * perform a partial reservation if the request exceeds free space.
         */
        error = -ENOSPC;
        do {
                free = percpu_counter_sum(&mp->m_fdblocks) -
                                                mp->m_alloc_set_aside;
                if (!free)
                        break;

                delta = request - mp->m_resblks;
                lcounter = free - delta;
                if (lcounter < 0)
                        /* We can't satisfy the request, just get what we can */
                        fdblks_delta = free;
                else
                        fdblks_delta = delta;

                /*
                 * We'll either succeed in getting space from the free block
                 * count or we'll get an ENOSPC. If we get a ENOSPC, it means
                 * things changed while we were calculating fdblks_delta and so
                 * we should try again to see if there is anything left to
                 * reserve.
                 *
                 * Don't set the reserved flag here - we don't want to reserve
                 * the extra reserve blocks from the reserve.....
                 */
                spin_unlock(&mp->m_sb_lock);
                error = xfs_mod_fdblocks(mp, -fdblks_delta, 0);
                spin_lock(&mp->m_sb_lock);
        } while (error == -ENOSPC);

        /*
         * Update the reserve counters if blocks have been successfully
         * allocated.
         */
        if (!error && fdblks_delta) {
                mp->m_resblks += fdblks_delta;
                mp->m_resblks_avail += fdblks_delta;
        }

out:
        if (outval) {
                outval->resblks = mp->m_resblks;
                outval->resblks_avail = mp->m_resblks_avail;
        }

        spin_unlock(&mp->m_sb_lock);
        return error;
}

int
xfs_fs_goingdown(
        xfs_mount_t     *mp,
        uint32_t        inflags)
{
        switch (inflags) {
        case XFS_FSOP_GOING_FLAGS_DEFAULT: {
                struct super_block *sb = freeze_bdev(mp->m_super->s_bdev);

                if (sb && !IS_ERR(sb)) {
                        xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
                        thaw_bdev(sb->s_bdev, sb);
                }

                break;
        }
        case XFS_FSOP_GOING_FLAGS_LOGFLUSH:
                xfs_force_shutdown(mp, SHUTDOWN_FORCE_UMOUNT);
                break;
        case XFS_FSOP_GOING_FLAGS_NOLOGFLUSH:
                xfs_force_shutdown(mp,
                                SHUTDOWN_FORCE_UMOUNT | SHUTDOWN_LOG_IO_ERROR);
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

/*
 * Force a shutdown of the filesystem instantly while keeping the filesystem
 * consistent. We don't do an unmount here; just shutdown the shop, make sure
 * that absolutely nothing persistent happens to this filesystem after this
 * point.
 */
void
xfs_do_force_shutdown(
        xfs_mount_t     *mp,
        int             flags,
        char            *fname,
        int             lnnum)
{
        int             logerror;

        logerror = flags & SHUTDOWN_LOG_IO_ERROR;

        if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
                xfs_notice(mp,
        "%s(0x%x) called from line %d of file %s.  Return address = "PTR_FMT,
                        __func__, flags, lnnum, fname, __return_address);
        }
        /*
         * No need to duplicate efforts.
         */
        if (XFS_FORCED_SHUTDOWN(mp) && !logerror)
                return;

        /*
         * This flags XFS_MOUNT_FS_SHUTDOWN, makes sure that we don't
         * queue up anybody new on the log reservations, and wakes up
         * everybody who's sleeping on log reservations to tell them
         * the bad news.
         */
        if (xfs_log_force_umount(mp, logerror))
                return;

        if (flags & SHUTDOWN_CORRUPT_INCORE) {
                xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_CORRUPT,
    "Corruption of in-memory data detected.  Shutting down filesystem");
                if (XFS_ERRLEVEL_HIGH <= xfs_error_level)
                        xfs_stack_trace();
        } else if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
                if (logerror) {
                        xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_LOGERROR,
                "Log I/O Error Detected.  Shutting down filesystem");
                } else if (flags & SHUTDOWN_DEVICE_REQ) {
                        xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
                "All device paths lost.  Shutting down filesystem");
                } else if (!(flags & SHUTDOWN_REMOTE_REQ)) {
                        xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
                "I/O Error Detected. Shutting down filesystem");
                }
        }
        if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
                xfs_alert(mp,
        "Please umount the filesystem and rectify the problem(s)");
        }
}

/*
 * Reserve free space for per-AG metadata.
 */
int
xfs_fs_reserve_ag_blocks(
        struct xfs_mount        *mp)
{
        xfs_agnumber_t          agno;
        struct xfs_perag        *pag;
        int                     error = 0;
        int                     err2;

        for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
                pag = xfs_perag_get(mp, agno);
                err2 = xfs_ag_resv_init(pag);
                xfs_perag_put(pag);
                if (err2 && !error)
                        error = err2;
        }

        if (error && error != -ENOSPC) {
                xfs_warn(mp,
        "Error %d reserving per-AG metadata reserve pool.", error);
                xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
        }

        return error;
}

/*
 * Free space reserved for per-AG metadata.
 */
int
xfs_fs_unreserve_ag_blocks(
        struct xfs_mount        *mp)
{
        xfs_agnumber_t          agno;
        struct xfs_perag        *pag;
        int                     error = 0;
        int                     err2;

        for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
                pag = xfs_perag_get(mp, agno);
                err2 = xfs_ag_resv_free(pag);
                xfs_perag_put(pag);
                if (err2 && !error)
                        error = err2;
        }

        if (error)
                xfs_warn(mp,
        "Error %d freeing per-AG metadata reserve pool.", error);

        return error;
}