xfs: repair the AGFL
Repair the AGFL from the rmap data.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c
index aa18049..9ce3023 100644
--- a/fs/xfs/scrub/agheader_repair.c
+++ b/fs/xfs/scrub/agheader_repair.c
@@ -433,3 +433,284 @@ xrep_agf(
memcpy(agf, &old_agf, sizeof(old_agf));
return error;
}
+
+/* AGFL */
+
+struct xrep_agfl {
+ /* Bitmap of other OWN_AG metadata blocks. */
+ struct xfs_bitmap agmetablocks;
+
+ /* Bitmap of free space. */
+ struct xfs_bitmap *freesp;
+
+ struct xfs_scrub *sc;
+};
+
+/* Record all OWN_AG (free space btree) information from the rmap data. */
+STATIC int
+xrep_agfl_walk_rmap(
+ struct xfs_btree_cur *cur,
+ struct xfs_rmap_irec *rec,
+ void *priv)
+{
+ struct xrep_agfl *ra = priv;
+ xfs_fsblock_t fsb;
+ int error = 0;
+
+ if (xchk_should_terminate(ra->sc, &error))
+ return error;
+
+ /* Record all the OWN_AG blocks. */
+ if (rec->rm_owner == XFS_RMAP_OWN_AG) {
+ fsb = XFS_AGB_TO_FSB(cur->bc_mp, cur->bc_private.a.agno,
+ rec->rm_startblock);
+ error = xfs_bitmap_set(ra->freesp, fsb, rec->rm_blockcount);
+ if (error)
+ return error;
+ }
+
+ return xfs_bitmap_set_btcur_path(&ra->agmetablocks, cur);
+}
+
+/*
+ * Map out all the non-AGFL OWN_AG space in this AG so that we can deduce
+ * which blocks belong to the AGFL.
+ *
+ * Compute the set of old AGFL blocks by subtracting from the list of OWN_AG
+ * blocks the list of blocks owned by all other OWN_AG metadata (bnobt, cntbt,
+ * rmapbt). These are the old AGFL blocks, so return that list and the number
+ * of blocks we're actually going to put back on the AGFL.
+ */
+STATIC int
+xrep_agfl_collect_blocks(
+ struct xfs_scrub *sc,
+ struct xfs_buf *agf_bp,
+ struct xfs_bitmap *agfl_extents,
+ xfs_agblock_t *flcount)
+{
+ struct xrep_agfl ra;
+ struct xfs_mount *mp = sc->mp;
+ struct xfs_btree_cur *cur;
+ struct xfs_bitmap_range *br;
+ struct xfs_bitmap_range *n;
+ int error;
+
+ ra.sc = sc;
+ ra.freesp = agfl_extents;
+ xfs_bitmap_init(&ra.agmetablocks);
+
+ /* Find all space used by the free space btrees & rmapbt. */
+ cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno);
+ error = xfs_rmap_query_all(cur, xrep_agfl_walk_rmap, &ra);
+ if (error)
+ goto err;
+ xfs_btree_del_cursor(cur, error);
+
+ /* Find all blocks currently being used by the bnobt. */
+ cur = xfs_allocbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno,
+ XFS_BTNUM_BNO);
+ error = xfs_bitmap_set_btblocks(&ra.agmetablocks, cur);
+ if (error)
+ goto err;
+ xfs_btree_del_cursor(cur, error);
+
+ /* Find all blocks currently being used by the cntbt. */
+ cur = xfs_allocbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.agno,
+ XFS_BTNUM_CNT);
+ error = xfs_bitmap_set_btblocks(&ra.agmetablocks, cur);
+ if (error)
+ goto err;
+
+ xfs_btree_del_cursor(cur, error);
+
+ /*
+ * Drop the freesp meta blocks that are in use by btrees.
+ * The remaining blocks /should/ be AGFL blocks.
+ */
+ error = xfs_bitmap_disunion(agfl_extents, &ra.agmetablocks);
+ xfs_bitmap_destroy(&ra.agmetablocks);
+ if (error)
+ return error;
+
+ /*
+ * Calculate the new AGFL size. If we found more blocks than fit in
+ * the AGFL we'll free them later.
+ */
+ *flcount = 0;
+ for_each_xfs_bitmap_extent(br, n, agfl_extents) {
+ *flcount += br->len;
+ if (*flcount > xfs_agfl_size(mp))
+ break;
+ }
+ if (*flcount > xfs_agfl_size(mp))
+ *flcount = xfs_agfl_size(mp);
+ return 0;
+
+err:
+ xfs_bitmap_destroy(&ra.agmetablocks);
+ xfs_btree_del_cursor(cur, error);
+ return error;
+}
+
+/* Update the AGF and reset the in-core state. */
+STATIC void
+xrep_agfl_update_agf(
+ struct xfs_scrub *sc,
+ struct xfs_buf *agf_bp,
+ xfs_agblock_t flcount)
+{
+ struct xfs_agf *agf = XFS_BUF_TO_AGF(agf_bp);
+
+ ASSERT(flcount <= xfs_agfl_size(sc->mp));
+
+ /* Trigger fdblocks recalculation */
+ xfs_force_summary_recalc(sc->mp);
+
+ /* Update the AGF counters. */
+ if (sc->sa.pag->pagf_init)
+ sc->sa.pag->pagf_flcount = flcount;
+ agf->agf_flfirst = cpu_to_be32(0);
+ agf->agf_flcount = cpu_to_be32(flcount);
+ agf->agf_fllast = cpu_to_be32(flcount - 1);
+
+ xfs_alloc_log_agf(sc->tp, agf_bp,
+ XFS_AGF_FLFIRST | XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
+}
+
+/* Write out a totally new AGFL. */
+STATIC void
+xrep_agfl_init_header(
+ struct xfs_scrub *sc,
+ struct xfs_buf *agfl_bp,
+ struct xfs_bitmap *agfl_extents,
+ xfs_agblock_t flcount)
+{
+ struct xfs_mount *mp = sc->mp;
+ __be32 *agfl_bno;
+ struct xfs_bitmap_range *br;
+ struct xfs_bitmap_range *n;
+ struct xfs_agfl *agfl;
+ xfs_agblock_t agbno;
+ unsigned int fl_off;
+
+ ASSERT(flcount <= xfs_agfl_size(mp));
+
+ /*
+ * Start rewriting the header by setting the bno[] array to
+ * NULLAGBLOCK, then setting AGFL header fields.
+ */
+ agfl = XFS_BUF_TO_AGFL(agfl_bp);
+ memset(agfl, 0xFF, BBTOB(agfl_bp->b_length));
+ agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC);
+ agfl->agfl_seqno = cpu_to_be32(sc->sa.agno);
+ uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid);
+
+ /*
+ * Fill the AGFL with the remaining blocks. If agfl_extents has more
+ * blocks than fit in the AGFL, they will be freed in a subsequent
+ * step.
+ */
+ fl_off = 0;
+ agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, agfl_bp);
+ for_each_xfs_bitmap_extent(br, n, agfl_extents) {
+ agbno = XFS_FSB_TO_AGBNO(mp, br->start);
+
+ trace_xrep_agfl_insert(mp, sc->sa.agno, agbno, br->len);
+
+ while (br->len > 0 && fl_off < flcount) {
+ agfl_bno[fl_off] = cpu_to_be32(agbno);
+ fl_off++;
+ agbno++;
+
+ /*
+ * We've now used br->start by putting it in the AGFL,
+ * so bump br so that we don't reap the block later.
+ */
+ br->start++;
+ br->len--;
+ }
+
+ if (br->len)
+ break;
+ list_del(&br->list);
+ kmem_free(br);
+ }
+
+ /* Write new AGFL to disk. */
+ xfs_trans_buf_set_type(sc->tp, agfl_bp, XFS_BLFT_AGFL_BUF);
+ xfs_trans_log_buf(sc->tp, agfl_bp, 0, BBTOB(agfl_bp->b_length) - 1);
+}
+
+/* Repair the AGFL. */
+int
+xrep_agfl(
+ struct xfs_scrub *sc)
+{
+ struct xfs_owner_info oinfo;
+ struct xfs_bitmap agfl_extents;
+ struct xfs_mount *mp = sc->mp;
+ struct xfs_buf *agf_bp;
+ struct xfs_buf *agfl_bp;
+ xfs_agblock_t flcount;
+ int error;
+
+ /* We require the rmapbt to rebuild anything. */
+ if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
+ return -EOPNOTSUPP;
+
+ xchk_perag_get(sc->mp, &sc->sa);
+ xfs_bitmap_init(&agfl_extents);
+
+ /*
+ * Read the AGF so that we can query the rmapbt. We hope that there's
+ * nothing wrong with the AGF, but all the AG header repair functions
+ * have this chicken-and-egg problem.
+ */
+ error = xfs_alloc_read_agf(mp, sc->tp, sc->sa.agno, 0, &agf_bp);
+ if (error)
+ return error;
+ if (!agf_bp)
+ return -ENOMEM;
+
+ /*
+ * Make sure we have the AGFL buffer, as scrub might have decided it
+ * was corrupt after xfs_alloc_read_agfl failed with -EFSCORRUPTED.
+ */
+ error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
+ XFS_AG_DADDR(mp, sc->sa.agno, XFS_AGFL_DADDR(mp)),
+ XFS_FSS_TO_BB(mp, 1), 0, &agfl_bp, NULL);
+ if (error)
+ return error;
+ agfl_bp->b_ops = &xfs_agfl_buf_ops;
+
+ /* Gather all the extents we're going to put on the new AGFL. */
+ error = xrep_agfl_collect_blocks(sc, agf_bp, &agfl_extents, &flcount);
+ if (error)
+ goto err;
+
+ /*
+ * Update AGF and AGFL. We reset the global free block counter when
+ * we adjust the AGF flcount (which can fail) so avoid updating any
+ * buffers until we know that part works.
+ */
+ xrep_agfl_update_agf(sc, agf_bp, flcount);
+ xrep_agfl_init_header(sc, agfl_bp, &agfl_extents, flcount);
+
+ /*
+ * Ok, the AGFL should be ready to go now. Roll the transaction to
+ * make the new AGFL permanent before we start using it to return
+ * freespace overflow to the freespace btrees.
+ */
+ sc->sa.agf_bp = agf_bp;
+ sc->sa.agfl_bp = agfl_bp;
+ error = xrep_roll_ag_trans(sc);
+ if (error)
+ goto err;
+
+ /* Dump any AGFL overflow. */
+ xfs_rmap_ag_owner(&oinfo, XFS_RMAP_OWN_AG);
+ return xrep_reap_extents(sc, &agfl_extents, &oinfo, XFS_AG_RESV_AGFL);
+err:
+ xfs_bitmap_destroy(&agfl_extents);
+ return error;
+}