xfs: scrub in-core metadata

Whenever we load a buffer, explicitly re-call the structure verifier to
ensure that memory isn't corrupting things.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

6 files changed, 57 insertions, 0 deletions

diff --git a/fs/xfs/scrub/agheader.c b/fs/xfs/scrub/agheader.c
index 20a3bebdee06..fd975524f460 100644
--- a/fs/xfs/scrub/agheader.c
+++ b/fs/xfs/scrub/agheader.c
@@ -611,6 +611,7 @@ xfs_scrub_agf(
                         &sc->sa.agf_bp, &sc->sa.agfl_bp);
         if (!xfs_scrub_process_error(sc, agno, XFS_AGF_BLOCK(sc->mp), &error))
                 goto out;
+        xfs_scrub_buffer_recheck(sc, sc->sa.agf_bp);
 
         agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
 
@@ -780,6 +781,7 @@ xfs_scrub_agfl(
                 goto out;
         if (!sc->sa.agf_bp)
                 return -EFSCORRUPTED;
+        xfs_scrub_buffer_recheck(sc, sc->sa.agfl_bp);
 
         xfs_scrub_agfl_xref(sc);
 
@@ -902,6 +904,7 @@ xfs_scrub_agi(
                         &sc->sa.agf_bp, &sc->sa.agfl_bp);
         if (!xfs_scrub_process_error(sc, agno, XFS_AGI_BLOCK(sc->mp), &error))
                 goto out;
+        xfs_scrub_buffer_recheck(sc, sc->sa.agi_bp);
 
         agi = XFS_BUF_TO_AGI(sc->sa.agi_bp);
 
diff --git a/fs/xfs/scrub/btree.c b/fs/xfs/scrub/btree.c
index 0589d4efbf6b..54218168c8f9 100644
--- a/fs/xfs/scrub/btree.c
+++ b/fs/xfs/scrub/btree.c
@@ -314,6 +314,8 @@ xfs_scrub_btree_block_check_sibling(
         pp = xfs_btree_ptr_addr(ncur, ncur->bc_ptrs[level + 1], pblock);
         if (!xfs_scrub_btree_ptr_ok(bs, level + 1, pp))
                 goto out;
+        if (pbp)
+                xfs_scrub_buffer_recheck(bs->sc, pbp);
 
         if (xfs_btree_diff_two_ptrs(cur, pp, sibling))
                 xfs_scrub_btree_set_corrupt(bs->sc, cur, level);
@@ -486,6 +488,8 @@ xfs_scrub_btree_get_block(
                 xfs_scrub_btree_set_corrupt(bs->sc, bs->cur, level);
                 return 0;
         }
+        if (*pbp)
+                xfs_scrub_buffer_recheck(bs->sc, *pbp);
 
         /*
          * Check the block's owner; this function absorbs error codes
diff --git a/fs/xfs/scrub/common.c b/fs/xfs/scrub/common.c
index f5df8f2859d7..8033ab9d8f47 100644
--- a/fs/xfs/scrub/common.c
+++ b/fs/xfs/scrub/common.c
@@ -756,3 +756,26 @@ xfs_scrub_should_check_xref(
         *error = 0;
         return false;
 }
+
+/* Run the structure verifiers on in-memory buffers to detect bad memory. */
+void
+xfs_scrub_buffer_recheck(
+        struct xfs_scrub_context        *sc,
+        struct xfs_buf                  *bp)
+{
+        xfs_failaddr_t                  fa;
+
+        if (bp->b_ops == NULL) {
+                xfs_scrub_block_set_corrupt(sc, bp);
+                return;
+        }
+        if (bp->b_ops->verify_struct == NULL) {
+                xfs_scrub_set_incomplete(sc);
+                return;
+        }
+        fa = bp->b_ops->verify_struct(bp);
+        if (!fa)
+                return;
+        sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+        trace_xfs_scrub_block_error(sc, bp->b_bn, fa);
+}
diff --git a/fs/xfs/scrub/common.h b/fs/xfs/scrub/common.h
index bf88a677f6e7..ddb65d22c76a 100644
--- a/fs/xfs/scrub/common.h
+++ b/fs/xfs/scrub/common.h
@@ -158,5 +158,6 @@ int xfs_scrub_setup_ag_btree(struct xfs_scrub_context *sc,
 int xfs_scrub_get_inode(struct xfs_scrub_context *sc, struct xfs_inode *ip_in);
 int xfs_scrub_setup_inode_contents(struct xfs_scrub_context *sc,
                                    struct xfs_inode *ip, unsigned int resblks);
+void xfs_scrub_buffer_recheck(struct xfs_scrub_context *sc, struct xfs_buf *bp);
 
 #endif  /* __XFS_SCRUB_COMMON_H__ */
diff --git a/fs/xfs/scrub/dabtree.c b/fs/xfs/scrub/dabtree.c
index d94edd93cba8..bffdb7dc09bf 100644
--- a/fs/xfs/scrub/dabtree.c
+++ b/fs/xfs/scrub/dabtree.c
@@ -233,11 +233,28 @@ xfs_scrub_da_btree_write_verify(
                 return;
         }
 }
+static void *
+xfs_scrub_da_btree_verify(
+        struct xfs_buf          *bp)
+{
+        struct xfs_da_blkinfo   *info = bp->b_addr;
+
+        switch (be16_to_cpu(info->magic)) {
+        case XFS_DIR2_LEAF1_MAGIC:
+        case XFS_DIR3_LEAF1_MAGIC:
+                bp->b_ops = &xfs_dir3_leaf1_buf_ops;
+                return bp->b_ops->verify_struct(bp);
+        default:
+                bp->b_ops = &xfs_da3_node_buf_ops;
+                return bp->b_ops->verify_struct(bp);
+        }
+}
 
 static const struct xfs_buf_ops xfs_scrub_da_btree_buf_ops = {
         .name = "xfs_scrub_da_btree",
         .verify_read = xfs_scrub_da_btree_read_verify,
         .verify_write = xfs_scrub_da_btree_write_verify,
+        .verify_struct = xfs_scrub_da_btree_verify,
 };
 
 /* Check a block's sibling. */
@@ -276,6 +293,9 @@ xfs_scrub_da_btree_block_check_sibling(
                 xfs_scrub_da_set_corrupt(ds, level);
                 return error;
         }
+        if (ds->state->altpath.blk[level].bp)
+                xfs_scrub_buffer_recheck(ds->sc,
+                                ds->state->altpath.blk[level].bp);
 
         /* Compare upper level pointer to sibling pointer. */
         if (ds->state->altpath.blk[level].blkno != sibling)
@@ -358,6 +378,8 @@ xfs_scrub_da_btree_block(
                         &xfs_scrub_da_btree_buf_ops);
         if (!xfs_scrub_da_process_error(ds, level, &error))
                 goto out_nobuf;
+        if (blk->bp)
+                xfs_scrub_buffer_recheck(ds->sc, blk->bp);
 
         /*
          * We didn't find a dir btree root block, which means that
diff --git a/fs/xfs/scrub/dir.c b/fs/xfs/scrub/dir.c
index e75826bb6516..f5a0d179eac0 100644
--- a/fs/xfs/scrub/dir.c
+++ b/fs/xfs/scrub/dir.c
@@ -237,6 +237,7 @@ xfs_scrub_dir_rec(
                 xfs_scrub_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
                 goto out;
         }
+        xfs_scrub_buffer_recheck(ds->sc, bp);
 
         /* Retrieve the entry, sanity check it, and compare hashes. */
         dent = (struct xfs_dir2_data_entry *)(((char *)bp->b_addr) + off);
@@ -324,6 +325,7 @@ xfs_scrub_directory_data_bestfree(
         }
         if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
                 goto out;
+        xfs_scrub_buffer_recheck(sc, bp);
 
         /* XXX: Check xfs_dir3_data_hdr.pad is zero once we start setting it. */
 
@@ -474,6 +476,7 @@ xfs_scrub_directory_leaf1_bestfree(
         error = xfs_dir3_leaf_read(sc->tp, sc->ip, lblk, -1, &bp);
         if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
                 goto out;
+        xfs_scrub_buffer_recheck(sc, bp);
 
         leaf = bp->b_addr;
         d_ops->leaf_hdr_from_disk(&leafhdr, leaf);
@@ -559,6 +562,7 @@ xfs_scrub_directory_free_bestfree(
         error = xfs_dir2_free_read(sc->tp, sc->ip, lblk, &bp);
         if (!xfs_scrub_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
                 goto out;
+        xfs_scrub_buffer_recheck(sc, bp);
 
         if (xfs_sb_version_hascrc(&sc->mp->m_sb)) {
                 struct xfs_dir3_free_hdr        *hdr3 = bp->b_addr;