Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

[cris-mirror.git] / fs / xfs / scrub / ialloc.c

/*
 * Copyright (C) 2017 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_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_btree.h"
#include "xfs_bit.h"
#include "xfs_log_format.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_ialloc.h"
#include "xfs_ialloc_btree.h"
#include "xfs_icache.h"
#include "xfs_rmap.h"
#include "xfs_log.h"
#include "xfs_trans_priv.h"
#include "scrub/xfs_scrub.h"
#include "scrub/scrub.h"
#include "scrub/common.h"
#include "scrub/btree.h"
#include "scrub/trace.h"

/*
 * Set us up to scrub inode btrees.
 * If we detect a discrepancy between the inobt and the inode,
 * try again after forcing logged inode cores out to disk.
 */
int
xfs_scrub_setup_ag_iallocbt(
        struct xfs_scrub_context        *sc,
        struct xfs_inode                *ip)
{
        return xfs_scrub_setup_ag_btree(sc, ip, sc->try_harder);
}

/* Inode btree scrubber. */

/*
 * If we're checking the finobt, cross-reference with the inobt.
 * Otherwise we're checking the inobt; if there is an finobt, make sure
 * we have a record or not depending on freecount.
 */
static inline void
xfs_scrub_iallocbt_chunk_xref_other(
        struct xfs_scrub_context        *sc,
        struct xfs_inobt_rec_incore     *irec,
        xfs_agino_t                     agino)
{
        struct xfs_btree_cur            **pcur;
        bool                            has_irec;
        int                             error;

        if (sc->sm->sm_type == XFS_SCRUB_TYPE_FINOBT)
                pcur = &sc->sa.ino_cur;
        else
                pcur = &sc->sa.fino_cur;
        if (!(*pcur))
                return;
        error = xfs_ialloc_has_inode_record(*pcur, agino, agino, &has_irec);
        if (!xfs_scrub_should_check_xref(sc, &error, pcur))
                return;
        if (((irec->ir_freecount > 0 && !has_irec) ||
             (irec->ir_freecount == 0 && has_irec)))
                xfs_scrub_btree_xref_set_corrupt(sc, *pcur, 0);
}

/* Cross-reference with the other btrees. */
STATIC void
xfs_scrub_iallocbt_chunk_xref(
        struct xfs_scrub_context        *sc,
        struct xfs_inobt_rec_incore     *irec,
        xfs_agino_t                     agino,
        xfs_agblock_t                   agbno,
        xfs_extlen_t                    len)
{
        struct xfs_owner_info           oinfo;

        if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
                return;

        xfs_scrub_xref_is_used_space(sc, agbno, len);
        xfs_scrub_iallocbt_chunk_xref_other(sc, irec, agino);
        xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INODES);
        xfs_scrub_xref_is_owned_by(sc, agbno, len, &oinfo);
        xfs_scrub_xref_is_not_shared(sc, agbno, len);
}

/* Is this chunk worth checking? */
STATIC bool
xfs_scrub_iallocbt_chunk(
        struct xfs_scrub_btree          *bs,
        struct xfs_inobt_rec_incore     *irec,
        xfs_agino_t                     agino,
        xfs_extlen_t                    len)
{
        struct xfs_mount                *mp = bs->cur->bc_mp;
        xfs_agnumber_t                  agno = bs->cur->bc_private.a.agno;
        xfs_agblock_t                   bno;

        bno = XFS_AGINO_TO_AGBNO(mp, agino);
        if (bno + len <= bno ||
            !xfs_verify_agbno(mp, agno, bno) ||
            !xfs_verify_agbno(mp, agno, bno + len - 1))
                xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);

        xfs_scrub_iallocbt_chunk_xref(bs->sc, irec, agino, bno, len);

        return true;
}

/* Count the number of free inodes. */
static unsigned int
xfs_scrub_iallocbt_freecount(
        xfs_inofree_t                   freemask)
{
        BUILD_BUG_ON(sizeof(freemask) != sizeof(__u64));
        return hweight64(freemask);
}

/* Check a particular inode with ir_free. */
STATIC int
xfs_scrub_iallocbt_check_cluster_freemask(
        struct xfs_scrub_btree          *bs,
        xfs_ino_t                       fsino,
        xfs_agino_t                     chunkino,
        xfs_agino_t                     clusterino,
        struct xfs_inobt_rec_incore     *irec,
        struct xfs_buf                  *bp)
{
        struct xfs_dinode               *dip;
        struct xfs_mount                *mp = bs->cur->bc_mp;
        bool                            inode_is_free = false;
        bool                            freemask_ok;
        bool                            inuse;
        int                             error = 0;

        if (xfs_scrub_should_terminate(bs->sc, &error))
                return error;

        dip = xfs_buf_offset(bp, clusterino * mp->m_sb.sb_inodesize);
        if (be16_to_cpu(dip->di_magic) != XFS_DINODE_MAGIC ||
            (dip->di_version >= 3 &&
             be64_to_cpu(dip->di_ino) != fsino + clusterino)) {
                xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
                goto out;
        }

        if (irec->ir_free & XFS_INOBT_MASK(chunkino + clusterino))
                inode_is_free = true;
        error = xfs_icache_inode_is_allocated(mp, bs->cur->bc_tp,
                        fsino + clusterino, &inuse);
        if (error == -ENODATA) {
                /* Not cached, just read the disk buffer */
                freemask_ok = inode_is_free ^ !!(dip->di_mode);
                if (!bs->sc->try_harder && !freemask_ok)
                        return -EDEADLOCK;
        } else if (error < 0) {
                /*
                 * Inode is only half assembled, or there was an IO error,
                 * or the verifier failed, so don't bother trying to check.
                 * The inode scrubber can deal with this.
                 */
                goto out;
        } else {
                /* Inode is all there. */
                freemask_ok = inode_is_free ^ inuse;
        }
        if (!freemask_ok)
                xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
out:
        return 0;
}

/* Make sure the free mask is consistent with what the inodes think. */
STATIC int
xfs_scrub_iallocbt_check_freemask(
        struct xfs_scrub_btree          *bs,
        struct xfs_inobt_rec_incore     *irec)
{
        struct xfs_owner_info           oinfo;
        struct xfs_imap                 imap;
        struct xfs_mount                *mp = bs->cur->bc_mp;
        struct xfs_dinode               *dip;
        struct xfs_buf                  *bp;
        xfs_ino_t                       fsino;
        xfs_agino_t                     nr_inodes;
        xfs_agino_t                     agino;
        xfs_agino_t                     chunkino;
        xfs_agino_t                     clusterino;
        xfs_agblock_t                   agbno;
        int                             blks_per_cluster;
        uint16_t                        holemask;
        uint16_t                        ir_holemask;
        int                             error = 0;

        /* Make sure the freemask matches the inode records. */
        blks_per_cluster = xfs_icluster_size_fsb(mp);
        nr_inodes = XFS_OFFBNO_TO_AGINO(mp, blks_per_cluster, 0);
        xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INODES);

        for (agino = irec->ir_startino;
             agino < irec->ir_startino + XFS_INODES_PER_CHUNK;
             agino += blks_per_cluster * mp->m_sb.sb_inopblock) {
                fsino = XFS_AGINO_TO_INO(mp, bs->cur->bc_private.a.agno, agino);
                chunkino = agino - irec->ir_startino;
                agbno = XFS_AGINO_TO_AGBNO(mp, agino);

                /* Compute the holemask mask for this cluster. */
                for (clusterino = 0, holemask = 0; clusterino < nr_inodes;
                     clusterino += XFS_INODES_PER_HOLEMASK_BIT)
                        holemask |= XFS_INOBT_MASK((chunkino + clusterino) /
                                        XFS_INODES_PER_HOLEMASK_BIT);

                /* The whole cluster must be a hole or not a hole. */
                ir_holemask = (irec->ir_holemask & holemask);
                if (ir_holemask != holemask && ir_holemask != 0) {
                        xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
                        continue;
                }

                /* If any part of this is a hole, skip it. */
                if (ir_holemask) {
                        xfs_scrub_xref_is_not_owned_by(bs->sc, agbno,
                                        blks_per_cluster, &oinfo);
                        continue;
                }

                xfs_scrub_xref_is_owned_by(bs->sc, agbno, blks_per_cluster,
                                &oinfo);

                /* Grab the inode cluster buffer. */
                imap.im_blkno = XFS_AGB_TO_DADDR(mp, bs->cur->bc_private.a.agno,
                                agbno);
                imap.im_len = XFS_FSB_TO_BB(mp, blks_per_cluster);
                imap.im_boffset = 0;

                error = xfs_imap_to_bp(mp, bs->cur->bc_tp, &imap,
                                &dip, &bp, 0, 0);
                if (!xfs_scrub_btree_process_error(bs->sc, bs->cur, 0, &error))
                        continue;

                /* Which inodes are free? */
                for (clusterino = 0; clusterino < nr_inodes; clusterino++) {
                        error = xfs_scrub_iallocbt_check_cluster_freemask(bs,
                                        fsino, chunkino, clusterino, irec, bp);
                        if (error) {
                                xfs_trans_brelse(bs->cur->bc_tp, bp);
                                return error;
                        }
                }

                xfs_trans_brelse(bs->cur->bc_tp, bp);
        }

        return error;
}

/* Scrub an inobt/finobt record. */
STATIC int
xfs_scrub_iallocbt_rec(
        struct xfs_scrub_btree          *bs,
        union xfs_btree_rec             *rec)
{
        struct xfs_mount                *mp = bs->cur->bc_mp;
        xfs_filblks_t                   *inode_blocks = bs->private;
        struct xfs_inobt_rec_incore     irec;
        uint64_t                        holes;
        xfs_agnumber_t                  agno = bs->cur->bc_private.a.agno;
        xfs_agino_t                     agino;
        xfs_agblock_t                   agbno;
        xfs_extlen_t                    len;
        int                             holecount;
        int                             i;
        int                             error = 0;
        unsigned int                    real_freecount;
        uint16_t                        holemask;

        xfs_inobt_btrec_to_irec(mp, rec, &irec);

        if (irec.ir_count > XFS_INODES_PER_CHUNK ||
            irec.ir_freecount > XFS_INODES_PER_CHUNK)
                xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);

        real_freecount = irec.ir_freecount +
                        (XFS_INODES_PER_CHUNK - irec.ir_count);
        if (real_freecount != xfs_scrub_iallocbt_freecount(irec.ir_free))
                xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);

        agino = irec.ir_startino;
        /* Record has to be properly aligned within the AG. */
        if (!xfs_verify_agino(mp, agno, agino) ||
            !xfs_verify_agino(mp, agno, agino + XFS_INODES_PER_CHUNK - 1)) {
                xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);
                goto out;
        }

        /* Make sure this record is aligned to cluster and inoalignmnt size. */
        agbno = XFS_AGINO_TO_AGBNO(mp, irec.ir_startino);
        if ((agbno & (xfs_ialloc_cluster_alignment(mp) - 1)) ||
            (agbno & (xfs_icluster_size_fsb(mp) - 1)))
                xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);

        *inode_blocks += XFS_B_TO_FSB(mp,
                        irec.ir_count * mp->m_sb.sb_inodesize);

        /* Handle non-sparse inodes */
        if (!xfs_inobt_issparse(irec.ir_holemask)) {
                len = XFS_B_TO_FSB(mp,
                                XFS_INODES_PER_CHUNK * mp->m_sb.sb_inodesize);
                if (irec.ir_count != XFS_INODES_PER_CHUNK)
                        xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);

                if (!xfs_scrub_iallocbt_chunk(bs, &irec, agino, len))
                        goto out;
                goto check_freemask;
        }

        /* Check each chunk of a sparse inode cluster. */
        holemask = irec.ir_holemask;
        holecount = 0;
        len = XFS_B_TO_FSB(mp,
                        XFS_INODES_PER_HOLEMASK_BIT * mp->m_sb.sb_inodesize);
        holes = ~xfs_inobt_irec_to_allocmask(&irec);
        if ((holes & irec.ir_free) != holes ||
            irec.ir_freecount > irec.ir_count)
                xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);

        for (i = 0; i < XFS_INOBT_HOLEMASK_BITS; i++) {
                if (holemask & 1)
                        holecount += XFS_INODES_PER_HOLEMASK_BIT;
                else if (!xfs_scrub_iallocbt_chunk(bs, &irec, agino, len))
                        break;
                holemask >>= 1;
                agino += XFS_INODES_PER_HOLEMASK_BIT;
        }

        if (holecount > XFS_INODES_PER_CHUNK ||
            holecount + irec.ir_count != XFS_INODES_PER_CHUNK)
                xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, 0);

check_freemask:
        error = xfs_scrub_iallocbt_check_freemask(bs, &irec);
        if (error)
                goto out;

out:
        return error;
}

/*
 * Make sure the inode btrees are as large as the rmap thinks they are.
 * Don't bother if we're missing btree cursors, as we're already corrupt.
 */
STATIC void
xfs_scrub_iallocbt_xref_rmap_btreeblks(
        struct xfs_scrub_context        *sc,
        int                             which)
{
        struct xfs_owner_info           oinfo;
        xfs_filblks_t                   blocks;
        xfs_extlen_t                    inobt_blocks = 0;
        xfs_extlen_t                    finobt_blocks = 0;
        int                             error;

        if (!sc->sa.ino_cur || !sc->sa.rmap_cur ||
            (xfs_sb_version_hasfinobt(&sc->mp->m_sb) && !sc->sa.fino_cur))
                return;

        /* Check that we saw as many inobt blocks as the rmap says. */
        error = xfs_btree_count_blocks(sc->sa.ino_cur, &inobt_blocks);
        if (!xfs_scrub_process_error(sc, 0, 0, &error))
                return;

        if (sc->sa.fino_cur) {
                error = xfs_btree_count_blocks(sc->sa.fino_cur, &finobt_blocks);
                if (!xfs_scrub_process_error(sc, 0, 0, &error))
                        return;
        }

        xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INOBT);
        error = xfs_scrub_count_rmap_ownedby_ag(sc, sc->sa.rmap_cur, &oinfo,
                        &blocks);
        if (!xfs_scrub_should_check_xref(sc, &error, &sc->sa.rmap_cur))
                return;
        if (blocks != inobt_blocks + finobt_blocks)
                xfs_scrub_btree_set_corrupt(sc, sc->sa.ino_cur, 0);
}

/*
 * Make sure that the inobt records point to the same number of blocks as
 * the rmap says are owned by inodes.
 */
STATIC void
xfs_scrub_iallocbt_xref_rmap_inodes(
        struct xfs_scrub_context        *sc,
        int                             which,
        xfs_filblks_t                   inode_blocks)
{
        struct xfs_owner_info           oinfo;
        xfs_filblks_t                   blocks;
        int                             error;

        if (!sc->sa.rmap_cur)
                return;

        /* Check that we saw as many inode blocks as the rmap knows about. */
        xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INODES);
        error = xfs_scrub_count_rmap_ownedby_ag(sc, sc->sa.rmap_cur, &oinfo,
                        &blocks);
        if (!xfs_scrub_should_check_xref(sc, &error, &sc->sa.rmap_cur))
                return;
        if (blocks != inode_blocks)
                xfs_scrub_btree_set_corrupt(sc, sc->sa.ino_cur, 0);
}

/* Scrub the inode btrees for some AG. */
STATIC int
xfs_scrub_iallocbt(
        struct xfs_scrub_context        *sc,
        xfs_btnum_t                     which)
{
        struct xfs_btree_cur            *cur;
        struct xfs_owner_info           oinfo;
        xfs_filblks_t                   inode_blocks = 0;
        int                             error;

        xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_INOBT);
        cur = which == XFS_BTNUM_INO ? sc->sa.ino_cur : sc->sa.fino_cur;
        error = xfs_scrub_btree(sc, cur, xfs_scrub_iallocbt_rec, &oinfo,
                        &inode_blocks);
        if (error)
                return error;

        xfs_scrub_iallocbt_xref_rmap_btreeblks(sc, which);

        /*
         * If we're scrubbing the inode btree, inode_blocks is the number of
         * blocks pointed to by all the inode chunk records.  Therefore, we
         * should compare to the number of inode chunk blocks that the rmap
         * knows about.  We can't do this for the finobt since it only points
         * to inode chunks with free inodes.
         */
        if (which == XFS_BTNUM_INO)
                xfs_scrub_iallocbt_xref_rmap_inodes(sc, which, inode_blocks);

        return error;
}

int
xfs_scrub_inobt(
        struct xfs_scrub_context        *sc)
{
        return xfs_scrub_iallocbt(sc, XFS_BTNUM_INO);
}

int
xfs_scrub_finobt(
        struct xfs_scrub_context        *sc)
{
        return xfs_scrub_iallocbt(sc, XFS_BTNUM_FINO);
}

/* See if an inode btree has (or doesn't have) an inode chunk record. */
static inline void
xfs_scrub_xref_inode_check(
        struct xfs_scrub_context        *sc,
        xfs_agblock_t                   agbno,
        xfs_extlen_t                    len,
        struct xfs_btree_cur            **icur,
        bool                            should_have_inodes)
{
        bool                            has_inodes;
        int                             error;

        if (!(*icur))
                return;

        error = xfs_ialloc_has_inodes_at_extent(*icur, agbno, len, &has_inodes);
        if (!xfs_scrub_should_check_xref(sc, &error, icur))
                return;
        if (has_inodes != should_have_inodes)
                xfs_scrub_btree_xref_set_corrupt(sc, *icur, 0);
}

/* xref check that the extent is not covered by inodes */
void
xfs_scrub_xref_is_not_inode_chunk(
        struct xfs_scrub_context        *sc,
        xfs_agblock_t                   agbno,
        xfs_extlen_t                    len)
{
        xfs_scrub_xref_inode_check(sc, agbno, len, &sc->sa.ino_cur, false);
        xfs_scrub_xref_inode_check(sc, agbno, len, &sc->sa.fino_cur, false);
}

/* xref check that the extent is covered by inodes */
void
xfs_scrub_xref_is_inode_chunk(
        struct xfs_scrub_context        *sc,
        xfs_agblock_t                   agbno,
        xfs_extlen_t                    len)
{
        xfs_scrub_xref_inode_check(sc, agbno, len, &sc->sa.ino_cur, true);
}