1 files changed, 141 insertions, 44 deletions

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index c1500b238520..2eecc49fc1b2 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -52,6 +52,71 @@ xfs_btree_magic(
 }
 
 /*
+ * These sibling pointer checks are optimised for null sibling pointers. This
+ * happens a lot, and we don't need to byte swap at runtime if the sibling
+ * pointer is NULL.
+ *
+ * These are explicitly marked at inline because the cost of calling them as
+ * functions instead of inlining them is about 36 bytes extra code per call site
+ * on x86-64. Yes, gcc-11 fails to inline them, and explicit inlining of these
+ * two sibling check functions reduces the compiled code size by over 300
+ * bytes.
+ */
+static inline xfs_failaddr_t
+xfs_btree_check_lblock_siblings(
+	struct xfs_mount	*mp,
+	struct xfs_btree_cur	*cur,
+	int			level,
+	xfs_fsblock_t		fsb,
+	__be64			dsibling)
+{
+	xfs_fsblock_t		sibling;
+
+	if (dsibling == cpu_to_be64(NULLFSBLOCK))
+		return NULL;
+
+	sibling = be64_to_cpu(dsibling);
+	if (sibling == fsb)
+		return __this_address;
+	if (level >= 0) {
+		if (!xfs_btree_check_lptr(cur, sibling, level + 1))
+			return __this_address;
+	} else {
+		if (!xfs_verify_fsbno(mp, sibling))
+			return __this_address;
+	}
+
+	return NULL;
+}
+
+static inline xfs_failaddr_t
+xfs_btree_check_sblock_siblings(
+	struct xfs_mount	*mp,
+	struct xfs_btree_cur	*cur,
+	int			level,
+	xfs_agnumber_t		agno,
+	xfs_agblock_t		agbno,
+	__be32			dsibling)
+{
+	xfs_agblock_t		sibling;
+
+	if (dsibling == cpu_to_be32(NULLAGBLOCK))
+		return NULL;
+
+	sibling = be32_to_cpu(dsibling);
+	if (sibling == agbno)
+		return __this_address;
+	if (level >= 0) {
+		if (!xfs_btree_check_sptr(cur, sibling, level + 1))
+			return __this_address;
+	} else {
+		if (!xfs_verify_agbno(mp, agno, sibling))
+			return __this_address;
+	}
+	return NULL;
+}
+
+/*
  * Check a long btree block header.  Return the address of the failing check,
  * or NULL if everything is ok.
  */
@@ -65,6 +130,8 @@ __xfs_btree_check_lblock(
 	struct xfs_mount	*mp = cur->bc_mp;
 	xfs_btnum_t		btnum = cur->bc_btnum;
 	int			crc = xfs_has_crc(mp);
+	xfs_failaddr_t		fa;
+	xfs_fsblock_t		fsb = NULLFSBLOCK;
 
 	if (crc) {
 		if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
@@ -83,16 +150,16 @@ __xfs_btree_check_lblock(
 	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;
+	if (bp)
+		fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
+
+	fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
+			block->bb_u.l.bb_leftsib);
+	if (!fa)
+		fa = xfs_btree_check_lblock_siblings(mp, cur, level, fsb,
+				block->bb_u.l.bb_rightsib);
+	return fa;
 }
 
 /* Check a long btree block header. */
@@ -130,6 +197,9 @@ __xfs_btree_check_sblock(
 	struct xfs_mount	*mp = cur->bc_mp;
 	xfs_btnum_t		btnum = cur->bc_btnum;
 	int			crc = xfs_has_crc(mp);
+	xfs_failaddr_t		fa;
+	xfs_agblock_t		agbno = NULLAGBLOCK;
+	xfs_agnumber_t		agno = NULLAGNUMBER;
 
 	if (crc) {
 		if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
@@ -146,16 +216,18 @@ __xfs_btree_check_sblock(
 	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;
+	if (bp) {
+		agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
+		agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp));
+	}
+
+	fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno, agbno,
+			block->bb_u.s.bb_leftsib);
+	if (!fa)
+		fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno,
+				 agbno, block->bb_u.s.bb_rightsib);
+	return fa;
 }
 
 /* Check a short btree block header. */
@@ -373,8 +445,14 @@ xfs_btree_del_cursor(
 			break;
 	}
 
+	/*
+	 * If we are doing a BMBT update, the number of unaccounted blocks
+	 * allocated during this cursor life time should be zero. If it's not
+	 * zero, then we should be shut down or on our way to shutdown due to
+	 * cancelling a dirty transaction on error.
+	 */
 	ASSERT(cur->bc_btnum != XFS_BTNUM_BMAP || cur->bc_ino.allocated == 0 ||
-	       xfs_is_shutdown(cur->bc_mp));
+	       xfs_is_shutdown(cur->bc_mp) || error != 0);
 	if (unlikely(cur->bc_flags & XFS_BTREE_STAGING))
 		kmem_free(cur->bc_ops);
 	if (!(cur->bc_flags & XFS_BTREE_LONG_PTRS) && cur->bc_ag.pag)
@@ -751,20 +829,20 @@ xfs_btree_lastrec(
  */
 void
 xfs_btree_offsets(
-	int64_t		fields,		/* bitmask of fields */
+	uint32_t	fields,		/* bitmask of fields */
 	const short	*offsets,	/* table of field offsets */
 	int		nbits,		/* number of bits to inspect */
 	int		*first,		/* output: first byte offset */
 	int		*last)		/* output: last byte offset */
 {
 	int		i;		/* current bit number */
-	int64_t		imask;		/* mask for current bit number */
+	uint32_t	imask;		/* mask for current bit number */
 
 	ASSERT(fields != 0);
 	/*
 	 * Find the lowest bit, so the first byte offset.
 	 */
-	for (i = 0, imask = 1LL; ; i++, imask <<= 1) {
+	for (i = 0, imask = 1u; ; i++, imask <<= 1) {
 		if (imask & fields) {
 			*first = offsets[i];
 			break;
@@ -773,7 +851,7 @@ xfs_btree_offsets(
 	/*
 	 * Find the highest bit, so the last byte offset.
 	 */
-	for (i = nbits - 1, imask = 1LL << i; ; i--, imask >>= 1) {
+	for (i = nbits - 1, imask = 1u << i; ; i--, imask >>= 1) {
 		if (imask & fields) {
 			*last = offsets[i + 1] - 1;
 			break;
@@ -1456,7 +1534,7 @@ void
 xfs_btree_log_block(
 	struct xfs_btree_cur	*cur,	/* btree cursor */
 	struct xfs_buf		*bp,	/* buffer containing btree block */
-	int			fields)	/* mask of fields: XFS_BB_... */
+	uint32_t		fields)	/* mask of fields: XFS_BB_... */
 {
 	int			first;	/* first byte offset logged */
 	int			last;	/* last byte offset logged */
@@ -3194,7 +3272,7 @@ xfs_btree_insrec(
 	struct xfs_btree_block	*block;	/* btree block */
 	struct xfs_buf		*bp;	/* buffer for block */
 	union xfs_btree_ptr	nptr;	/* new block ptr */
-	struct xfs_btree_cur	*ncur;	/* new btree cursor */
+	struct xfs_btree_cur	*ncur = NULL;	/* new btree cursor */
 	union xfs_btree_key	nkey;	/* new block key */
 	union xfs_btree_key	*lkey;
 	int			optr;	/* old key/record index */
@@ -3274,7 +3352,7 @@ xfs_btree_insrec(
 #ifdef DEBUG
 	error = xfs_btree_check_block(cur, block, level, bp);
 	if (error)
-		return error;
+		goto error0;
 #endif
 
 	/*
@@ -3294,7 +3372,7 @@ xfs_btree_insrec(
 		for (i = numrecs - ptr; i >= 0; i--) {
 			error = xfs_btree_debug_check_ptr(cur, pp, i, level);
 			if (error)
-				return error;
+				goto error0;
 		}
 
 		xfs_btree_shift_keys(cur, kp, 1, numrecs - ptr + 1);
@@ -3379,6 +3457,8 @@ xfs_btree_insrec(
 	return 0;
 
 error0:
+	if (ncur)
+		xfs_btree_del_cursor(ncur, error);
 	return error;
 }
 
@@ -4271,6 +4351,21 @@ xfs_btree_visit_block(
 	if (xfs_btree_ptr_is_null(cur, &rptr))
 		return -ENOENT;
 
+	/*
+	 * We only visit blocks once in this walk, so we have to avoid the
+	 * internal xfs_btree_lookup_get_block() optimisation where it will
+	 * return the same block without checking if the right sibling points
+	 * back to us and creates a cyclic reference in the btree.
+	 */
+	if (cur->bc_flags & XFS_BTREE_LONG_PTRS) {
+		if (be64_to_cpu(rptr.l) == XFS_DADDR_TO_FSB(cur->bc_mp,
+							xfs_buf_daddr(bp)))
+			return -EFSCORRUPTED;
+	} else {
+		if (be32_to_cpu(rptr.s) == xfs_daddr_to_agbno(cur->bc_mp,
+							xfs_buf_daddr(bp)))
+			return -EFSCORRUPTED;
+	}
 	return xfs_btree_lookup_get_block(cur, level, &rptr, &block);
 }
 
@@ -4445,20 +4540,21 @@ xfs_btree_lblock_verify(
 {
 	struct xfs_mount	*mp = bp->b_mount;
 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+	xfs_fsblock_t		fsb;
+	xfs_failaddr_t		fa;
 
 	/* numrecs verification */
 	if (be16_to_cpu(block->bb_numrecs) > max_recs)
 		return __this_address;
 
 	/* sibling pointer verification */
-	if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
-	    !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_leftsib)))
-		return __this_address;
-	if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
-	    !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_rightsib)))
-		return __this_address;
-
-	return NULL;
+	fsb = XFS_DADDR_TO_FSB(mp, xfs_buf_daddr(bp));
+	fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
+			block->bb_u.l.bb_leftsib);
+	if (!fa)
+		fa = xfs_btree_check_lblock_siblings(mp, NULL, -1, fsb,
+				block->bb_u.l.bb_rightsib);
+	return fa;
 }
 
 /**
@@ -4499,7 +4595,9 @@ xfs_btree_sblock_verify(
 {
 	struct xfs_mount	*mp = bp->b_mount;
 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
-	xfs_agblock_t		agno;
+	xfs_agnumber_t		agno;
+	xfs_agblock_t		agbno;
+	xfs_failaddr_t		fa;
 
 	/* numrecs verification */
 	if (be16_to_cpu(block->bb_numrecs) > max_recs)
@@ -4507,14 +4605,13 @@ xfs_btree_sblock_verify(
 
 	/* sibling pointer verification */
 	agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp));
-	if (block->bb_u.s.bb_leftsib != cpu_to_be32(NULLAGBLOCK) &&
-	    !xfs_verify_agbno(mp, agno, be32_to_cpu(block->bb_u.s.bb_leftsib)))
-		return __this_address;
-	if (block->bb_u.s.bb_rightsib != cpu_to_be32(NULLAGBLOCK) &&
-	    !xfs_verify_agbno(mp, agno, be32_to_cpu(block->bb_u.s.bb_rightsib)))
-		return __this_address;
-
-	return NULL;
+	agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
+	fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno,
+			block->bb_u.s.bb_leftsib);
+	if (!fa)
+		fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno,
+				block->bb_u.s.bb_rightsib);
+	return fa;
 }
 
 /*