From 858333dcf021a46baef6505beac329c495fbfcf3 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 16 Jan 2018 18:53:05 -0800 Subject: xfs: check btree block ownership with bnobt/rmapbt when scrubbing btree When scanning a metadata btree block, cross-reference the block location with the free space btree and the reverse mapping btree to ensure that the rmapbt knows about the block and the bnobt does not. Add a mechanism to defer checks when we happen to be scanning the bnobt/rmapbt itself because it's less efficient to repeatedly clone and destroy the cursor. This patch provides the framework to make btree block owner checks happen; the actual meat will be added in subsequent patches. Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner --- fs/xfs/scrub/btree.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) (limited to 'fs/xfs/scrub/btree.c') diff --git a/fs/xfs/scrub/btree.c b/fs/xfs/scrub/btree.c index 4751ed03b9fb..e671d694908b 100644 --- a/fs/xfs/scrub/btree.c +++ b/fs/xfs/scrub/btree.c @@ -361,6 +361,80 @@ out: return error; } +struct check_owner { + struct list_head list; + xfs_daddr_t daddr; + int level; +}; + +/* + * Make sure this btree block isn't in the free list and that there's + * an rmap record for it. + */ +STATIC int +xfs_scrub_btree_check_block_owner( + struct xfs_scrub_btree *bs, + int level, + xfs_daddr_t daddr) +{ + xfs_agnumber_t agno; + bool init_sa; + int error = 0; + + if (!bs->cur) + return 0; + + agno = xfs_daddr_to_agno(bs->cur->bc_mp, daddr); + + init_sa = bs->cur->bc_flags & XFS_BTREE_LONG_PTRS; + if (init_sa) { + error = xfs_scrub_ag_init(bs->sc, agno, &bs->sc->sa); + if (!xfs_scrub_btree_xref_process_error(bs->sc, bs->cur, + level, &error)) + return error; + } + + if (init_sa) + xfs_scrub_ag_free(bs->sc, &bs->sc->sa); + + return error; +} + +/* Check the owner of a btree block. */ +STATIC int +xfs_scrub_btree_check_owner( + struct xfs_scrub_btree *bs, + int level, + struct xfs_buf *bp) +{ + struct xfs_btree_cur *cur = bs->cur; + struct check_owner *co; + + if ((cur->bc_flags & XFS_BTREE_ROOT_IN_INODE) && bp == NULL) + return 0; + + /* + * We want to cross-reference each btree block with the bnobt + * and the rmapbt. We cannot cross-reference the bnobt or + * rmapbt while scanning the bnobt or rmapbt, respectively, + * because we cannot alter the cursor and we'd prefer not to + * duplicate cursors. Therefore, save the buffer daddr for + * later scanning. + */ + if (cur->bc_btnum == XFS_BTNUM_BNO || cur->bc_btnum == XFS_BTNUM_RMAP) { + co = kmem_alloc(sizeof(struct check_owner), + KM_MAYFAIL | KM_NOFS); + if (!co) + return -ENOMEM; + co->level = level; + co->daddr = XFS_BUF_ADDR(bp); + list_add_tail(&co->list, &bs->to_check); + return 0; + } + + return xfs_scrub_btree_check_block_owner(bs, level, XFS_BUF_ADDR(bp)); +} + /* * Grab and scrub a btree block given a btree pointer. Returns block * and buffer pointers (if applicable) if they're ok to use. @@ -396,6 +470,14 @@ xfs_scrub_btree_get_block( return 0; } + /* + * Check the block's owner; this function absorbs error codes + * for us. + */ + error = xfs_scrub_btree_check_owner(bs, level, *pbp); + if (error) + return error; + /* * Check the block's siblings; this function absorbs error codes * for us. @@ -467,6 +549,8 @@ xfs_scrub_btree( struct xfs_btree_block *block; int level; struct xfs_buf *bp; + struct check_owner *co; + struct check_owner *n; int i; int error = 0; @@ -558,5 +642,14 @@ xfs_scrub_btree( } out: + /* Process deferred owner checks on btree blocks. */ + list_for_each_entry_safe(co, n, &bs.to_check, list) { + if (!error && bs.cur) + error = xfs_scrub_btree_check_block_owner(&bs, + co->level, co->daddr); + list_del(&co->list); + kmem_free(co); + } + return error; } -- cgit v1.2.3