xfs: repair the AGFL (0e93d3f4) · Commits · EulixOS / Software / Kernel

fs/xfs/scrub/agheader_repair.c

+281 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

fs/xfs/scrub/bitmap.c

+92 −0

Original line number	Diff line number	Diff line
		@@ -9,6 +9,7 @@
		#include "xfs_format.h"
		#include "xfs_trans_resv.h"
		#include "xfs_mount.h"
		#include "xfs_btree.h"
		#include "scrub/xfs_scrub.h"
		#include "scrub/scrub.h"
		#include "scrub/common.h"
		@@ -209,3 +210,94 @@ xfs_bitmap_disunion(
		}
		#undef LEFT_ALIGNED
		#undef RIGHT_ALIGNED

		/*
		* Record all btree blocks seen while iterating all records of a btree.
		*
		* We know that the btree query_all function starts at the left edge and walks
		* towards the right edge of the tree. Therefore, we know that we can walk up
		* the btree cursor towards the root; if the pointer for a given level points
		* to the first record/key in that block, we haven't seen this block before;
		* and therefore we need to remember that we saw this block in the btree.
		*
		* So if our btree is:
		*
		* 4
		* / \| \
		* 1 2 3
		*
		* Pretend for this example that each leaf block has 100 btree records. For
		* the first btree record, we'll observe that bc_ptrs[0] == 1, so we record
		* that we saw block 1. Then we observe that bc_ptrs[1] == 1, so we record
		* block 4. The list is [1, 4].
		*
		* For the second btree record, we see that bc_ptrs[0] == 2, so we exit the
		* loop. The list remains [1, 4].
		*
		* For the 101st btree record, we've moved onto leaf block 2. Now
		* bc_ptrs[0] == 1 again, so we record that we saw block 2. We see that
		* bc_ptrs[1] == 2, so we exit the loop. The list is now [1, 4, 2].
		*
		* For the 102nd record, bc_ptrs[0] == 2, so we continue.
		*
		* For the 201st record, we've moved on to leaf block 3. bc_ptrs[0] == 1, so
		* we add 3 to the list. Now it is [1, 4, 2, 3].
		*
		* For the 300th record we just exit, with the list being [1, 4, 2, 3].
		*/

		/*
		* Record all the buffers pointed to by the btree cursor. Callers already
		* engaged in a btree walk should call this function to capture the list of
		* blocks going from the leaf towards the root.
		*/
		int
		xfs_bitmap_set_btcur_path(
		struct xfs_bitmap *bitmap,
		struct xfs_btree_cur *cur)
		{
		struct xfs_buf *bp;
		xfs_fsblock_t fsb;
		int i;
		int error;

		for (i = 0; i < cur->bc_nlevels && cur->bc_ptrs[i] == 1; i++) {
		xfs_btree_get_block(cur, i, &bp);
		if (!bp)
		continue;
		fsb = XFS_DADDR_TO_FSB(cur->bc_mp, bp->b_bn);
		error = xfs_bitmap_set(bitmap, fsb, 1);
		if (error)
		return error;
		}

		return 0;
		}

		/* Collect a btree's block in the bitmap. */
		STATIC int
		xfs_bitmap_collect_btblock(
		struct xfs_btree_cur *cur,
		int level,
		void *priv)
		{
		struct xfs_bitmap *bitmap = priv;
		struct xfs_buf *bp;
		xfs_fsblock_t fsbno;

		xfs_btree_get_block(cur, level, &bp);
		if (!bp)
		return 0;

		fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, bp->b_bn);
		return xfs_bitmap_set(bitmap, fsbno, 1);
		}

		/* Walk the btree and mark the bitmap wherever a btree block is found. */
		int
		xfs_bitmap_set_btblocks(
		struct xfs_bitmap *bitmap,
		struct xfs_btree_cur *cur)
		{
		return xfs_btree_visit_blocks(cur, xfs_bitmap_collect_btblock, bitmap);
		}

fs/xfs/scrub/bitmap.h

+4 −0

Original line number	Diff line number	Diff line
		@@ -28,5 +28,9 @@ void xfs_bitmap_destroy(struct xfs_bitmap *bitmap);

		int xfs_bitmap_set(struct xfs_bitmap *bitmap, uint64_t start, uint64_t len);
		int xfs_bitmap_disunion(struct xfs_bitmap bitmap, struct xfs_bitmap sub);
		int xfs_bitmap_set_btcur_path(struct xfs_bitmap *bitmap,
		struct xfs_btree_cur *cur);
		int xfs_bitmap_set_btblocks(struct xfs_bitmap *bitmap,
		struct xfs_btree_cur *cur);

		#endif /* __XFS_SCRUB_BITMAP_H__ */

fs/xfs/scrub/repair.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -59,6 +59,7 @@ int xrep_ino_dqattach(struct xfs_scrub *sc);
		int xrep_probe(struct xfs_scrub *sc);
		int xrep_superblock(struct xfs_scrub *sc);
		int xrep_agf(struct xfs_scrub *sc);
		int xrep_agfl(struct xfs_scrub *sc);

		#else

		@@ -83,6 +84,7 @@ xrep_calc_ag_resblks(
		#define xrep_probe xrep_notsupported
		#define xrep_superblock xrep_notsupported
		#define xrep_agf xrep_notsupported
		#define xrep_agfl xrep_notsupported

		#endif /* CONFIG_XFS_ONLINE_REPAIR */

fs/xfs/scrub/scrub.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -220,7 +220,7 @@ static const struct xchk_meta_ops meta_scrub_ops[] = {
		.type = ST_PERAG,
		.setup = xchk_setup_fs,
		.scrub = xchk_agfl,
		.repair = xrep_notsupported,
		.repair = xrep_agfl,
		},
		[XFS_SCRUB_TYPE_AGI] = { /* agi */
		.type = ST_PERAG,