1 files changed, 596 insertions, 0 deletions

diff --git a/fs/xfs/scrub/dabtree.c b/fs/xfs/scrub/dabtree.c
new file mode 100644
index 000000000..84fe3d33d
--- /dev/null
+++ b/fs/xfs/scrub/dabtree.c
@@ -0,0 +1,596 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2017 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ */
+#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_log_format.h"
+#include "xfs_trans.h"
+#include "xfs_inode.h"
+#include "xfs_dir2.h"
+#include "xfs_dir2_priv.h"
+#include "xfs_attr_leaf.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/trace.h"
+#include "scrub/dabtree.h"
+
+/* Directory/Attribute Btree */
+
+/*
+ * Check for da btree operation errors.  See the section about handling
+ * operational errors in common.c.
+ */
+bool
+xchk_da_process_error(
+	struct xchk_da_btree	*ds,
+	int			level,
+	int			*error)
+{
+	struct xfs_scrub	*sc = ds->sc;
+
+	if (*error == 0)
+		return true;
+
+	switch (*error) {
+	case -EDEADLOCK:
+		/* Used to restart an op with deadlock avoidance. */
+		trace_xchk_deadlock_retry(sc->ip, sc->sm, *error);
+		break;
+	case -EFSBADCRC:
+	case -EFSCORRUPTED:
+		/* Note the badness but don't abort. */
+		sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+		*error = 0;
+		fallthrough;
+	default:
+		trace_xchk_file_op_error(sc, ds->dargs.whichfork,
+				xfs_dir2_da_to_db(ds->dargs.geo,
+					ds->state->path.blk[level].blkno),
+				*error, __return_address);
+		break;
+	}
+	return false;
+}
+
+/*
+ * Check for da btree corruption.  See the section about handling
+ * operational errors in common.c.
+ */
+void
+xchk_da_set_corrupt(
+	struct xchk_da_btree	*ds,
+	int			level)
+{
+	struct xfs_scrub	*sc = ds->sc;
+
+	sc->sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
+
+	trace_xchk_fblock_error(sc, ds->dargs.whichfork,
+			xfs_dir2_da_to_db(ds->dargs.geo,
+				ds->state->path.blk[level].blkno),
+			__return_address);
+}
+
+static struct xfs_da_node_entry *
+xchk_da_btree_node_entry(
+	struct xchk_da_btree		*ds,
+	int				level)
+{
+	struct xfs_da_state_blk		*blk = &ds->state->path.blk[level];
+	struct xfs_da3_icnode_hdr	hdr;
+
+	ASSERT(blk->magic == XFS_DA_NODE_MAGIC);
+
+	xfs_da3_node_hdr_from_disk(ds->sc->mp, &hdr, blk->bp->b_addr);
+	return hdr.btree + blk->index;
+}
+
+/* Scrub a da btree hash (key). */
+int
+xchk_da_btree_hash(
+	struct xchk_da_btree		*ds,
+	int				level,
+	__be32				*hashp)
+{
+	struct xfs_da_node_entry	*entry;
+	xfs_dahash_t			hash;
+	xfs_dahash_t			parent_hash;
+
+	/* Is this hash in order? */
+	hash = be32_to_cpu(*hashp);
+	if (hash < ds->hashes[level])
+		xchk_da_set_corrupt(ds, level);
+	ds->hashes[level] = hash;
+
+	if (level == 0)
+		return 0;
+
+	/* Is this hash no larger than the parent hash? */
+	entry = xchk_da_btree_node_entry(ds, level - 1);
+	parent_hash = be32_to_cpu(entry->hashval);
+	if (parent_hash < hash)
+		xchk_da_set_corrupt(ds, level);
+
+	return 0;
+}
+
+/*
+ * Check a da btree pointer.  Returns true if it's ok to use this
+ * pointer.
+ */
+STATIC bool
+xchk_da_btree_ptr_ok(
+	struct xchk_da_btree	*ds,
+	int			level,
+	xfs_dablk_t		blkno)
+{
+	if (blkno < ds->lowest || (ds->highest != 0 && blkno >= ds->highest)) {
+		xchk_da_set_corrupt(ds, level);
+		return false;
+	}
+
+	return true;
+}
+
+/*
+ * The da btree scrubber can handle leaf1 blocks as a degenerate
+ * form of leafn blocks.  Since the regular da code doesn't handle
+ * leaf1, we must multiplex the verifiers.
+ */
+static void
+xchk_da_btree_read_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;
+		bp->b_ops->verify_read(bp);
+		return;
+	default:
+		/*
+		 * xfs_da3_node_buf_ops already know how to handle
+		 * DA*_NODE, ATTR*_LEAF, and DIR*_LEAFN blocks.
+		 */
+		bp->b_ops = &xfs_da3_node_buf_ops;
+		bp->b_ops->verify_read(bp);
+		return;
+	}
+}
+static void
+xchk_da_btree_write_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;
+		bp->b_ops->verify_write(bp);
+		return;
+	default:
+		/*
+		 * xfs_da3_node_buf_ops already know how to handle
+		 * DA*_NODE, ATTR*_LEAF, and DIR*_LEAFN blocks.
+		 */
+		bp->b_ops = &xfs_da3_node_buf_ops;
+		bp->b_ops->verify_write(bp);
+		return;
+	}
+}
+static void *
+xchk_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 xchk_da_btree_buf_ops = {
+	.name = "xchk_da_btree",
+	.verify_read = xchk_da_btree_read_verify,
+	.verify_write = xchk_da_btree_write_verify,
+	.verify_struct = xchk_da_btree_verify,
+};
+
+/* Check a block's sibling. */
+STATIC int
+xchk_da_btree_block_check_sibling(
+	struct xchk_da_btree	*ds,
+	int			level,
+	int			direction,
+	xfs_dablk_t		sibling)
+{
+	struct xfs_da_state_path *path = &ds->state->path;
+	struct xfs_da_state_path *altpath = &ds->state->altpath;
+	int			retval;
+	int			plevel;
+	int			error;
+
+	memcpy(altpath, path, sizeof(ds->state->altpath));
+
+	/*
+	 * If the pointer is null, we shouldn't be able to move the upper
+	 * level pointer anywhere.
+	 */
+	if (sibling == 0) {
+		error = xfs_da3_path_shift(ds->state, altpath, direction,
+				false, &retval);
+		if (error == 0 && retval == 0)
+			xchk_da_set_corrupt(ds, level);
+		error = 0;
+		goto out;
+	}
+
+	/* Move the alternate cursor one block in the direction given. */
+	error = xfs_da3_path_shift(ds->state, altpath, direction, false,
+			&retval);
+	if (!xchk_da_process_error(ds, level, &error))
+		goto out;
+	if (retval) {
+		xchk_da_set_corrupt(ds, level);
+		goto out;
+	}
+	if (altpath->blk[level].bp)
+		xchk_buffer_recheck(ds->sc, altpath->blk[level].bp);
+
+	/* Compare upper level pointer to sibling pointer. */
+	if (altpath->blk[level].blkno != sibling)
+		xchk_da_set_corrupt(ds, level);
+
+out:
+	/* Free all buffers in the altpath that aren't referenced from path. */
+	for (plevel = 0; plevel < altpath->active; plevel++) {
+		if (altpath->blk[plevel].bp == NULL ||
+		    (plevel < path->active &&
+		     altpath->blk[plevel].bp == path->blk[plevel].bp))
+			continue;
+
+		xfs_trans_brelse(ds->dargs.trans, altpath->blk[plevel].bp);
+		altpath->blk[plevel].bp = NULL;
+	}
+
+	return error;
+}
+
+/* Check a block's sibling pointers. */
+STATIC int
+xchk_da_btree_block_check_siblings(
+	struct xchk_da_btree	*ds,
+	int			level,
+	struct xfs_da_blkinfo	*hdr)
+{
+	xfs_dablk_t		forw;
+	xfs_dablk_t		back;
+	int			error = 0;
+
+	forw = be32_to_cpu(hdr->forw);
+	back = be32_to_cpu(hdr->back);
+
+	/* Top level blocks should not have sibling pointers. */
+	if (level == 0) {
+		if (forw != 0 || back != 0)
+			xchk_da_set_corrupt(ds, level);
+		return 0;
+	}
+
+	/*
+	 * Check back (left) and forw (right) pointers.  These functions
+	 * absorb error codes for us.
+	 */
+	error = xchk_da_btree_block_check_sibling(ds, level, 0, back);
+	if (error)
+		goto out;
+	error = xchk_da_btree_block_check_sibling(ds, level, 1, forw);
+
+out:
+	memset(&ds->state->altpath, 0, sizeof(ds->state->altpath));
+	return error;
+}
+
+/* Load a dir/attribute block from a btree. */
+STATIC int
+xchk_da_btree_block(
+	struct xchk_da_btree		*ds,
+	int				level,
+	xfs_dablk_t			blkno)
+{
+	struct xfs_da_state_blk		*blk;
+	struct xfs_da_intnode		*node;
+	struct xfs_da_node_entry	*btree;
+	struct xfs_da3_blkinfo		*hdr3;
+	struct xfs_da_args		*dargs = &ds->dargs;
+	struct xfs_inode		*ip = ds->dargs.dp;
+	xfs_ino_t			owner;
+	int				*pmaxrecs;
+	struct xfs_da3_icnode_hdr	nodehdr;
+	int				error = 0;
+
+	blk = &ds->state->path.blk[level];
+	ds->state->path.active = level + 1;
+
+	/* Release old block. */
+	if (blk->bp) {
+		xfs_trans_brelse(dargs->trans, blk->bp);
+		blk->bp = NULL;
+	}
+
+	/* Check the pointer. */
+	blk->blkno = blkno;
+	if (!xchk_da_btree_ptr_ok(ds, level, blkno))
+		goto out_nobuf;
+
+	/* Read the buffer. */
+	error = xfs_da_read_buf(dargs->trans, dargs->dp, blk->blkno,
+			XFS_DABUF_MAP_HOLE_OK, &blk->bp, dargs->whichfork,
+			&xchk_da_btree_buf_ops);
+	if (!xchk_da_process_error(ds, level, &error))
+		goto out_nobuf;
+	if (blk->bp)
+		xchk_buffer_recheck(ds->sc, blk->bp);
+
+	/*
+	 * We didn't find a dir btree root block, which means that
+	 * there's no LEAF1/LEAFN tree (at least not where it's supposed
+	 * to be), so jump out now.
+	 */
+	if (ds->dargs.whichfork == XFS_DATA_FORK && level == 0 &&
+			blk->bp == NULL)
+		goto out_nobuf;
+
+	/* It's /not/ ok for attr trees not to have a da btree. */
+	if (blk->bp == NULL) {
+		xchk_da_set_corrupt(ds, level);
+		goto out_nobuf;
+	}
+
+	hdr3 = blk->bp->b_addr;
+	blk->magic = be16_to_cpu(hdr3->hdr.magic);
+	pmaxrecs = &ds->maxrecs[level];
+
+	/* We only started zeroing the header on v5 filesystems. */
+	if (xfs_has_crc(ds->sc->mp) && hdr3->hdr.pad)
+		xchk_da_set_corrupt(ds, level);
+
+	/* Check the owner. */
+	if (xfs_has_crc(ip->i_mount)) {
+		owner = be64_to_cpu(hdr3->owner);
+		if (owner != ip->i_ino)
+			xchk_da_set_corrupt(ds, level);
+	}
+
+	/* Check the siblings. */
+	error = xchk_da_btree_block_check_siblings(ds, level, &hdr3->hdr);
+	if (error)
+		goto out;
+
+	/* Interpret the buffer. */
+	switch (blk->magic) {
+	case XFS_ATTR_LEAF_MAGIC:
+	case XFS_ATTR3_LEAF_MAGIC:
+		xfs_trans_buf_set_type(dargs->trans, blk->bp,
+				XFS_BLFT_ATTR_LEAF_BUF);
+		blk->magic = XFS_ATTR_LEAF_MAGIC;
+		blk->hashval = xfs_attr_leaf_lasthash(blk->bp, pmaxrecs);
+		if (ds->tree_level != 0)
+			xchk_da_set_corrupt(ds, level);
+		break;
+	case XFS_DIR2_LEAFN_MAGIC:
+	case XFS_DIR3_LEAFN_MAGIC:
+		xfs_trans_buf_set_type(dargs->trans, blk->bp,
+				XFS_BLFT_DIR_LEAFN_BUF);
+		blk->magic = XFS_DIR2_LEAFN_MAGIC;
+		blk->hashval = xfs_dir2_leaf_lasthash(ip, blk->bp, pmaxrecs);
+		if (ds->tree_level != 0)
+			xchk_da_set_corrupt(ds, level);
+		break;
+	case XFS_DIR2_LEAF1_MAGIC:
+	case XFS_DIR3_LEAF1_MAGIC:
+		xfs_trans_buf_set_type(dargs->trans, blk->bp,
+				XFS_BLFT_DIR_LEAF1_BUF);
+		blk->magic = XFS_DIR2_LEAF1_MAGIC;
+		blk->hashval = xfs_dir2_leaf_lasthash(ip, blk->bp, pmaxrecs);
+		if (ds->tree_level != 0)
+			xchk_da_set_corrupt(ds, level);
+		break;
+	case XFS_DA_NODE_MAGIC:
+	case XFS_DA3_NODE_MAGIC:
+		xfs_trans_buf_set_type(dargs->trans, blk->bp,
+				XFS_BLFT_DA_NODE_BUF);
+		blk->magic = XFS_DA_NODE_MAGIC;
+		node = blk->bp->b_addr;
+		xfs_da3_node_hdr_from_disk(ip->i_mount, &nodehdr, node);
+		btree = nodehdr.btree;
+		*pmaxrecs = nodehdr.count;
+		blk->hashval = be32_to_cpu(btree[*pmaxrecs - 1].hashval);
+		if (level == 0) {
+			if (nodehdr.level >= XFS_DA_NODE_MAXDEPTH) {
+				xchk_da_set_corrupt(ds, level);
+				goto out_freebp;
+			}
+			ds->tree_level = nodehdr.level;
+		} else {
+			if (ds->tree_level != nodehdr.level) {
+				xchk_da_set_corrupt(ds, level);
+				goto out_freebp;
+			}
+		}
+
+		/* XXX: Check hdr3.pad32 once we know how to fix it. */
+		break;
+	default:
+		xchk_da_set_corrupt(ds, level);
+		goto out_freebp;
+	}
+
+	/*
+	 * If we've been handed a block that is below the dabtree root, does
+	 * its hashval match what the parent block expected to see?
+	 */
+	if (level > 0) {
+		struct xfs_da_node_entry	*key;
+
+		key = xchk_da_btree_node_entry(ds, level - 1);
+		if (be32_to_cpu(key->hashval) != blk->hashval) {
+			xchk_da_set_corrupt(ds, level);
+			goto out_freebp;
+		}
+	}
+
+out:
+	return error;
+out_freebp:
+	xfs_trans_brelse(dargs->trans, blk->bp);
+	blk->bp = NULL;
+out_nobuf:
+	blk->blkno = 0;
+	return error;
+}
+
+/* Visit all nodes and leaves of a da btree. */
+int
+xchk_da_btree(
+	struct xfs_scrub		*sc,
+	int				whichfork,
+	xchk_da_btree_rec_fn		scrub_fn,
+	void				*private)
+{
+	struct xchk_da_btree		*ds;
+	struct xfs_mount		*mp = sc->mp;
+	struct xfs_da_state_blk		*blks;
+	struct xfs_da_node_entry	*key;
+	xfs_dablk_t			blkno;
+	int				level;
+	int				error;
+
+	/* Skip short format data structures; no btree to scan. */
+	if (!xfs_ifork_has_extents(xfs_ifork_ptr(sc->ip, whichfork)))
+		return 0;
+
+	/* Set up initial da state. */
+	ds = kmem_zalloc(sizeof(struct xchk_da_btree), KM_NOFS | KM_MAYFAIL);
+	if (!ds)
+		return -ENOMEM;
+	ds->dargs.dp = sc->ip;
+	ds->dargs.whichfork = whichfork;
+	ds->dargs.trans = sc->tp;
+	ds->dargs.op_flags = XFS_DA_OP_OKNOENT;
+	ds->state = xfs_da_state_alloc(&ds->dargs);
+	ds->sc = sc;
+	ds->private = private;
+	if (whichfork == XFS_ATTR_FORK) {
+		ds->dargs.geo = mp->m_attr_geo;
+		ds->lowest = 0;
+		ds->highest = 0;
+	} else {
+		ds->dargs.geo = mp->m_dir_geo;
+		ds->lowest = ds->dargs.geo->leafblk;
+		ds->highest = ds->dargs.geo->freeblk;
+	}
+	blkno = ds->lowest;
+	level = 0;
+
+	/* Find the root of the da tree, if present. */
+	blks = ds->state->path.blk;
+	error = xchk_da_btree_block(ds, level, blkno);
+	if (error)
+		goto out_state;
+	/*
+	 * We didn't find a block at ds->lowest, which means that there's
+	 * no LEAF1/LEAFN tree (at least not where it's supposed to be),
+	 * so jump out now.
+	 */
+	if (blks[level].bp == NULL)
+		goto out_state;
+
+	blks[level].index = 0;
+	while (level >= 0 && level < XFS_DA_NODE_MAXDEPTH) {
+		/* Handle leaf block. */
+		if (blks[level].magic != XFS_DA_NODE_MAGIC) {
+			/* End of leaf, pop back towards the root. */
+			if (blks[level].index >= ds->maxrecs[level]) {
+				if (level > 0)
+					blks[level - 1].index++;
+				ds->tree_level++;
+				level--;
+				continue;
+			}
+
+			/* Dispatch record scrubbing. */
+			error = scrub_fn(ds, level);
+			if (error)
+				break;
+			if (xchk_should_terminate(sc, &error) ||
+			    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
+				break;
+
+			blks[level].index++;
+			continue;
+		}
+
+
+		/* End of node, pop back towards the root. */
+		if (blks[level].index >= ds->maxrecs[level]) {
+			if (level > 0)
+				blks[level - 1].index++;
+			ds->tree_level++;
+			level--;
+			continue;
+		}
+
+		/* Hashes in order for scrub? */
+		key = xchk_da_btree_node_entry(ds, level);
+		error = xchk_da_btree_hash(ds, level, &key->hashval);
+		if (error)
+			goto out;
+
+		/* Drill another level deeper. */
+		blkno = be32_to_cpu(key->before);
+		level++;
+		if (level >= XFS_DA_NODE_MAXDEPTH) {
+			/* Too deep! */
+			xchk_da_set_corrupt(ds, level - 1);
+			break;
+		}
+		ds->tree_level--;
+		error = xchk_da_btree_block(ds, level, blkno);
+		if (error)
+			goto out;
+		if (blks[level].bp == NULL)
+			goto out;
+
+		blks[level].index = 0;
+	}
+
+out:
+	/* Release all the buffers we're tracking. */
+	for (level = 0; level < XFS_DA_NODE_MAXDEPTH; level++) {
+		if (blks[level].bp == NULL)
+			continue;
+		xfs_trans_brelse(sc->tp, blks[level].bp);
+		blks[level].bp = NULL;
+	}
+
+out_state:
+	xfs_da_state_free(ds->state);
+	kmem_free(ds);
+	return error;
+}