1 files changed, 149 insertions, 110 deletions

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 5bfb88261c7e..5f33adf8eecb 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -29,6 +29,7 @@
 #include "xfs_inode_item.h"
 #include "xfs_buf_item.h"
 #include "xfs_btree.h"
+#include "xfs_errortag.h"
 #include "xfs_error.h"
 #include "xfs_trace.h"
 #include "xfs_cksum.h"
@@ -63,44 +64,63 @@ xfs_btree_magic(
 	return magic;
 }
 
-STATIC int				/* error (0 or EFSCORRUPTED) */
-xfs_btree_check_lblock(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	struct xfs_btree_block	*block,	/* btree long form block pointer */
-	int			level,	/* level of the btree block */
-	struct xfs_buf		*bp)	/* buffer for block, if any */
+/*
+ * Check a long btree block header.  Return the address of the failing check,
+ * or NULL if everything is ok.
+ */
+xfs_failaddr_t
+__xfs_btree_check_lblock(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	int			level,
+	struct xfs_buf		*bp)
 {
-	int			lblock_ok = 1; /* block passes checks */
-	struct xfs_mount	*mp;	/* file system mount point */
+	struct xfs_mount	*mp = cur->bc_mp;
 	xfs_btnum_t		btnum = cur->bc_btnum;
-	int			crc;
-
-	mp = cur->bc_mp;
-	crc = xfs_sb_version_hascrc(&mp->m_sb);
+	int			crc = xfs_sb_version_hascrc(&mp->m_sb);
 
 	if (crc) {
-		lblock_ok = lblock_ok &&
-			uuid_equal(&block->bb_u.l.bb_uuid,
-				   &mp->m_sb.sb_meta_uuid) &&
-			block->bb_u.l.bb_blkno == cpu_to_be64(
-				bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
+		if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
+			return __this_address;
+		if (block->bb_u.l.bb_blkno !=
+		    cpu_to_be64(bp ? bp->b_bn : XFS_BUF_DADDR_NULL))
+			return __this_address;
+		if (block->bb_u.l.bb_pad != cpu_to_be32(0))
+			return __this_address;
 	}
 
-	lblock_ok = lblock_ok &&
-		be32_to_cpu(block->bb_magic) == xfs_btree_magic(crc, btnum) &&
-		be16_to_cpu(block->bb_level) == level &&
-		be16_to_cpu(block->bb_numrecs) <=
-			cur->bc_ops->get_maxrecs(cur, level) &&
-		block->bb_u.l.bb_leftsib &&
-		(block->bb_u.l.bb_leftsib == cpu_to_be64(NULLFSBLOCK) ||
-		 XFS_FSB_SANITY_CHECK(mp,
-			be64_to_cpu(block->bb_u.l.bb_leftsib))) &&
-		block->bb_u.l.bb_rightsib &&
-		(block->bb_u.l.bb_rightsib == cpu_to_be64(NULLFSBLOCK) ||
-		 XFS_FSB_SANITY_CHECK(mp,
-			be64_to_cpu(block->bb_u.l.bb_rightsib)));
-
-	if (unlikely(XFS_TEST_ERROR(!lblock_ok, mp,
+	if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
+		return __this_address;
+	if (be16_to_cpu(block->bb_level) != level)
+		return __this_address;
+	if (be16_to_cpu(block->bb_numrecs) >
+	    cur->bc_ops->get_maxrecs(cur, level))
+		return __this_address;
+	if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
+	    !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_leftsib),
+			level + 1))
+		return __this_address;
+	if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
+	    !xfs_btree_check_lptr(cur, be64_to_cpu(block->bb_u.l.bb_rightsib),
+			level + 1))
+		return __this_address;
+
+	return NULL;
+}
+
+/* Check a long btree block header. */
+static int
+xfs_btree_check_lblock(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	int			level,
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = cur->bc_mp;
+	xfs_failaddr_t		fa;
+
+	fa = __xfs_btree_check_lblock(cur, block, level, bp);
+	if (unlikely(XFS_TEST_ERROR(fa != NULL, mp,
 			XFS_ERRTAG_BTREE_CHECK_LBLOCK))) {
 		if (bp)
 			trace_xfs_btree_corrupt(bp, _RET_IP_);
@@ -110,48 +130,61 @@ xfs_btree_check_lblock(
 	return 0;
 }
 
-STATIC int				/* error (0 or EFSCORRUPTED) */
-xfs_btree_check_sblock(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	struct xfs_btree_block	*block,	/* btree short form block pointer */
-	int			level,	/* level of the btree block */
-	struct xfs_buf		*bp)	/* buffer containing block */
+/*
+ * Check a short btree block header.  Return the address of the failing check,
+ * or NULL if everything is ok.
+ */
+xfs_failaddr_t
+__xfs_btree_check_sblock(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	int			level,
+	struct xfs_buf		*bp)
 {
-	struct xfs_mount	*mp;	/* file system mount point */
-	struct xfs_buf		*agbp;	/* buffer for ag. freespace struct */
-	struct xfs_agf		*agf;	/* ag. freespace structure */
-	xfs_agblock_t		agflen;	/* native ag. freespace length */
-	int			sblock_ok = 1; /* block passes checks */
+	struct xfs_mount	*mp = cur->bc_mp;
 	xfs_btnum_t		btnum = cur->bc_btnum;
-	int			crc;
-
-	mp = cur->bc_mp;
-	crc = xfs_sb_version_hascrc(&mp->m_sb);
-	agbp = cur->bc_private.a.agbp;
-	agf = XFS_BUF_TO_AGF(agbp);
-	agflen = be32_to_cpu(agf->agf_length);
+	int			crc = xfs_sb_version_hascrc(&mp->m_sb);
 
 	if (crc) {
-		sblock_ok = sblock_ok &&
-			uuid_equal(&block->bb_u.s.bb_uuid,
-				   &mp->m_sb.sb_meta_uuid) &&
-			block->bb_u.s.bb_blkno == cpu_to_be64(
-				bp ? bp->b_bn : XFS_BUF_DADDR_NULL);
+		if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
+			return __this_address;
+		if (block->bb_u.s.bb_blkno !=
+		    cpu_to_be64(bp ? bp->b_bn : XFS_BUF_DADDR_NULL))
+			return __this_address;
 	}
 
-	sblock_ok = sblock_ok &&
-		be32_to_cpu(block->bb_magic) == xfs_btree_magic(crc, btnum) &&
-		be16_to_cpu(block->bb_level) == level &&
-		be16_to_cpu(block->bb_numrecs) <=
-			cur->bc_ops->get_maxrecs(cur, level) &&
-		(block->bb_u.s.bb_leftsib == cpu_to_be32(NULLAGBLOCK) ||
-		 be32_to_cpu(block->bb_u.s.bb_leftsib) < agflen) &&
-		block->bb_u.s.bb_leftsib &&
-		(block->bb_u.s.bb_rightsib == cpu_to_be32(NULLAGBLOCK) ||
-		 be32_to_cpu(block->bb_u.s.bb_rightsib) < agflen) &&
-		block->bb_u.s.bb_rightsib;
-
-	if (unlikely(XFS_TEST_ERROR(!sblock_ok, mp,
+	if (be32_to_cpu(block->bb_magic) != xfs_btree_magic(crc, btnum))
+		return __this_address;
+	if (be16_to_cpu(block->bb_level) != level)
+		return __this_address;
+	if (be16_to_cpu(block->bb_numrecs) >
+	    cur->bc_ops->get_maxrecs(cur, level))
+		return __this_address;
+	if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) &&
+	    !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_leftsib),
+			level + 1))
+		return __this_address;
+	if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) &&
+	    !xfs_btree_check_sptr(cur, be32_to_cpu(block->bb_u.s.bb_rightsib),
+			level + 1))
+		return __this_address;
+
+	return NULL;
+}
+
+/* Check a short btree block header. */
+STATIC int
+xfs_btree_check_sblock(
+	struct xfs_btree_cur	*cur,
+	struct xfs_btree_block	*block,
+	int			level,
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = cur->bc_mp;
+	xfs_failaddr_t		fa;
+
+	fa = __xfs_btree_check_sblock(cur, block, level, bp);
+	if (unlikely(XFS_TEST_ERROR(fa != NULL, mp,
 			XFS_ERRTAG_BTREE_CHECK_SBLOCK))) {
 		if (bp)
 			trace_xfs_btree_corrupt(bp, _RET_IP_);
@@ -177,59 +210,53 @@ xfs_btree_check_block(
 		return xfs_btree_check_sblock(cur, block, level, bp);
 }
 
-/*
- * Check that (long) pointer is ok.
- */
-int					/* error (0 or EFSCORRUPTED) */
+/* Check that this long pointer is valid and points within the fs. */
+bool
 xfs_btree_check_lptr(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	xfs_fsblock_t		bno,	/* btree block disk address */
-	int			level)	/* btree block level */
+	struct xfs_btree_cur	*cur,
+	xfs_fsblock_t		fsbno,
+	int			level)
 {
-	XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
-		level > 0 &&
-		bno != NULLFSBLOCK &&
-		XFS_FSB_SANITY_CHECK(cur->bc_mp, bno));
-	return 0;
+	if (level <= 0)
+		return false;
+	return xfs_verify_fsbno(cur->bc_mp, fsbno);
 }
 
-#ifdef DEBUG
-/*
- * Check that (short) pointer is ok.
- */
-STATIC int				/* error (0 or EFSCORRUPTED) */
+/* Check that this short pointer is valid and points within the AG. */
+bool
 xfs_btree_check_sptr(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	xfs_agblock_t		bno,	/* btree block disk address */
-	int			level)	/* btree block level */
+	struct xfs_btree_cur	*cur,
+	xfs_agblock_t		agbno,
+	int			level)
 {
-	xfs_agblock_t		agblocks = cur->bc_mp->m_sb.sb_agblocks;
-
-	XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
-		level > 0 &&
-		bno != NULLAGBLOCK &&
-		bno != 0 &&
-		bno < agblocks);
-	return 0;
+	if (level <= 0)
+		return false;
+	return xfs_verify_agbno(cur->bc_mp, cur->bc_private.a.agno, agbno);
 }
 
+#ifdef DEBUG
 /*
- * Check that block ptr is ok.
+ * Check that a given (indexed) btree pointer at a certain level of a
+ * btree is valid and doesn't point past where it should.
  */
-STATIC int				/* error (0 or EFSCORRUPTED) */
+static int
 xfs_btree_check_ptr(
-	struct xfs_btree_cur	*cur,	/* btree cursor */
-	union xfs_btree_ptr	*ptr,	/* btree block disk address */
-	int			index,	/* offset from ptr to check */
-	int			level)	/* btree block level */
+	struct xfs_btree_cur	*cur,
+	union xfs_btree_ptr	*ptr,
+	int			index,
+	int			level)
 {
 	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
-		return xfs_btree_check_lptr(cur,
-				be64_to_cpu((&ptr->l)[index]), level);
+		XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
+				xfs_btree_check_lptr(cur,
+					be64_to_cpu((&ptr->l)[index]), level));
 	} else {
-		return xfs_btree_check_sptr(cur,
-				be32_to_cpu((&ptr->s)[index]), level);
+		XFS_WANT_CORRUPTED_RETURN(cur->bc_mp,
+				xfs_btree_check_sptr(cur,
+					be32_to_cpu((&ptr->s)[index]), level));
 	}
+
+	return 0;
 }
 #endif
 
@@ -1027,7 +1054,7 @@ xfs_btree_setbuf(
 	}
 }
 
-STATIC int
+bool
 xfs_btree_ptr_is_null(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_ptr	*ptr)
@@ -1052,7 +1079,7 @@ xfs_btree_set_ptr_null(
 /*
  * Get/set/init sibling pointers
  */
-STATIC void
+void
 xfs_btree_get_sibling(
 	struct xfs_btree_cur	*cur,
 	struct xfs_btree_block	*block,
@@ -2001,7 +2028,7 @@ error0:
 }
 
 /* Find the high key storage area from a regular key. */
-STATIC union xfs_btree_key *
+union xfs_btree_key *
 xfs_btree_high_key_from_key(
 	struct xfs_btree_cur	*cur,
 	union xfs_btree_key	*key)
@@ -2075,7 +2102,7 @@ xfs_btree_get_node_keys(
 }
 
 /* Derive the keys for any btree block. */
-STATIC void
+void
 xfs_btree_get_keys(
 	struct xfs_btree_cur	*cur,
 	struct xfs_btree_block	*block,
@@ -4914,3 +4941,15 @@ xfs_btree_count_blocks(
 	return xfs_btree_visit_blocks(cur, xfs_btree_count_blocks_helper,
 			blocks);
 }
+
+/* Compare two btree pointers. */
+int64_t
+xfs_btree_diff_two_ptrs(
+	struct xfs_btree_cur		*cur,
+	const union xfs_btree_ptr	*a,
+	const union xfs_btree_ptr	*b)
+{
+	if (cur->bc_flags & XFS_BTREE_LONG_PTRS)
+		return (int64_t)be64_to_cpu(a->l) - be64_to_cpu(b->l);
+	return (int64_t)be32_to_cpu(a->s) - be32_to_cpu(b->s);
+}