hpfs: annotate btree nodes, get rid of bitfields mess

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/hpfs/anode.c

@@ -20,7 +20,7 @@ secno hpfs_bplus_lookup(struct super_block *s, struct inode *inode,
 	int c1, c2 = 0;
 	go_down:
 	if (hpfs_sb(s)->sb_chk) if (hpfs_stop_cycles(s, a, &c1, &c2, "hpfs_bplus_lookup")) return -1;
-	if (btree->internal) {
+	if (bp_internal(btree)) {
 		for (i = 0; i < btree->n_used_nodes; i++)
 			if (le32_to_cpu(btree->u.internal[i].file_secno) > sec) {
 				a = le32_to_cpu(btree->u.internal[i].down);
@@ -82,7 +82,7 @@ secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsi
 		brelse(bh);
 		return -1;
 	}
-	if (btree->internal) {
+	if (bp_internal(btree)) {
 		a = le32_to_cpu(btree->u.internal[n].down);
 		btree->u.internal[n].file_secno = cpu_to_le32(-1);
 		mark_buffer_dirty(bh);
@@ -129,12 +129,12 @@ secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsi
 		}
 		if (a == node && fnod) {
 			anode->up = cpu_to_le32(node);
-			anode->btree.fnode_parent = 1;
+			anode->btree.flags |= BP_fnode_parent;
 			anode->btree.n_used_nodes = btree->n_used_nodes;
 			anode->btree.first_free = btree->first_free;
 			anode->btree.n_free_nodes = 40 - anode->btree.n_used_nodes;
 			memcpy(&anode->u, &btree->u, btree->n_used_nodes * 12);
-			btree->internal = 1;
+			btree->flags |= BP_internal;
 			btree->n_free_nodes = 11;
 			btree->n_used_nodes = 1;
 			btree->first_free = cpu_to_le16((char *)&(btree->u.internal[1]) - (char *)btree);
@@ -184,7 +184,10 @@ secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsi
 			hpfs_free_sectors(s, ra, 1);
 			if ((anode = hpfs_map_anode(s, na, &bh))) {
 				anode->up = cpu_to_le32(up);
-				anode->btree.fnode_parent = up == node && fnod;
+				if (up == node && fnod)
+					anode->btree.flags |= BP_fnode_parent;
+				else
+					anode->btree.flags &= ~BP_fnode_parent;
 				mark_buffer_dirty(bh);
 				brelse(bh);
 			}
@@ -198,7 +201,7 @@ secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsi
 		if ((new_anode = hpfs_alloc_anode(s, a, &na, &bh))) {
 			anode = new_anode;
 			/*anode->up = cpu_to_le32(up != -1 ? up : ra);*/
-			anode->btree.internal = 1;
+			anode->btree.flags |= BP_internal;
 			anode->btree.n_used_nodes = 1;
 			anode->btree.n_free_nodes = 59;
 			anode->btree.first_free = cpu_to_le16(16);
@@ -215,7 +218,8 @@ secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsi
 	}
 	if ((anode = hpfs_map_anode(s, na, &bh))) {
 		anode->up = cpu_to_le32(node);
-		if (fnod) anode->btree.fnode_parent = 1;
+		if (fnod)
+			anode->btree.flags |= BP_fnode_parent;
 		mark_buffer_dirty(bh);
 		brelse(bh);
 	}
@@ -234,18 +238,19 @@ secno hpfs_add_sector_to_btree(struct super_block *s, secno node, int fnod, unsi
 	}
 	ranode->up = cpu_to_le32(node);
 	memcpy(&ranode->btree, btree, le16_to_cpu(btree->first_free));
-	if (fnod) ranode->btree.fnode_parent = 1;
-	ranode->btree.n_free_nodes = (ranode->btree.internal ? 60 : 40) - ranode->btree.n_used_nodes;
-	if (ranode->btree.internal) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
+	if (fnod)
+		ranode->btree.flags |= BP_fnode_parent;
+	ranode->btree.n_free_nodes = (bp_internal(&ranode->btree) ? 60 : 40) - ranode->btree.n_used_nodes;
+	if (bp_internal(&ranode->btree)) for (n = 0; n < ranode->btree.n_used_nodes; n++) {
 		struct anode *unode;
 		if ((unode = hpfs_map_anode(s, le32_to_cpu(ranode->u.internal[n].down), &bh1))) {
 			unode->up = cpu_to_le32(ra);
-			unode->btree.fnode_parent = 0;
+			unode->btree.flags &= ~BP_fnode_parent;
 			mark_buffer_dirty(bh1);
 			brelse(bh1);
 		}
 	}
-	btree->internal = 1;
+	btree->flags |= BP_internal;
 	btree->n_free_nodes = fnod ? 10 : 58;
 	btree->n_used_nodes = 2;
 	btree->first_free = cpu_to_le16((char *)&btree->u.internal[2] - (char *)btree);
@@ -278,7 +283,7 @@ void hpfs_remove_btree(struct super_block *s, struct bplus_header *btree)
 	int d1, d2;
 	go_down:
 	d2 = 0;
-	while (btree1->internal) {
+	while (bp_internal(btree1)) {
 		ano = le32_to_cpu(btree1->u.internal[pos].down);
 		if (level) brelse(bh);
 		if (hpfs_sb(s)->sb_chk)
@@ -412,13 +417,13 @@ void hpfs_truncate_btree(struct super_block *s, secno f, int fno, unsigned secs)
 			btree->n_free_nodes = 8;
 			btree->n_used_nodes = 0;
 			btree->first_free = cpu_to_le16(8);
-			btree->internal = 0;
+			btree->flags &= ~BP_internal;
 			mark_buffer_dirty(bh);
 		} else hpfs_free_sectors(s, f, 1);
 		brelse(bh);
 		return;
 	}
-	while (btree->internal) {
+	while (bp_internal(btree)) {
 		nodes = btree->n_used_nodes + btree->n_free_nodes;
 		for (i = 0; i < btree->n_used_nodes; i++)
 			if (le32_to_cpu(btree->u.internal[i].file_secno) >= secs) goto f;

fs/hpfs/hpfs.h

@@ -375,50 +375,36 @@ struct hpfs_dirent {
 
 struct bplus_leaf_node
 {
-  u32 file_secno;			/* first file sector in extent */
-  u32 length;				/* length, sectors */
-  secno disk_secno;			/* first corresponding disk sector */
+  __le32 file_secno;			/* first file sector in extent */
+  __le32 length;			/* length, sectors */
+  __le32 disk_secno;			/* first corresponding disk sector */
 };
 
 struct bplus_internal_node
 {
-  u32 file_secno;			/* subtree maps sectors < this  */
-  anode_secno down;			/* pointer to subtree */
+  __le32 file_secno;			/* subtree maps sectors < this  */
+  __le32 down;				/* pointer to subtree */
 };
 
+enum {
+	BP_hbff = 1,
+	BP_fnode_parent = 0x20,
+	BP_binary_search = 0x40,
+	BP_internal = 0x80
+};
 struct bplus_header
 {
-#ifdef __LITTLE_ENDIAN
-  u8 hbff: 1;			/* high bit of first free entry offset */
-  u8 flag1234: 4;
-  u8 fnode_parent: 1;			/* ? we're pointed to by an fnode,
-					   the data btree or some ea or the
-					   main ea bootage pointer ea_secno */
-					/* also can get set in fnodes, which
-					   may be a chkdsk glitch or may mean
-					   this bit is irrelevant in fnodes,
-					   or this interpretation is all wet */
-  u8 binary_search: 1;			/* suggest binary search (unused) */
-  u8 internal: 1;			/* 1 -> (internal) tree of anodes
-					   0 -> (leaf) list of extents */
-#else
-  u8 internal: 1;			/* 1 -> (internal) tree of anodes
-					   0 -> (leaf) list of extents */
-  u8 binary_search: 1;			/* suggest binary search (unused) */
-  u8 fnode_parent: 1;			/* ? we're pointed to by an fnode,
+  u8 flags;				/* bit 0 - high bit of first free entry offset
+					   bit 5 - we're pointed to by an fnode,
 					   the data btree or some ea or the
-					   main ea bootage pointer ea_secno */
-					/* also can get set in fnodes, which
-					   may be a chkdsk glitch or may mean
-					   this bit is irrelevant in fnodes,
-					   or this interpretation is all wet */
-  u8 flag1234: 4;
-  u8 hbff: 1;			/* high bit of first free entry offset */
-#endif
+					   main ea bootage pointer ea_secno
+					   bit 6 - suggest binary search (unused)
+					   bit 7 - 1 -> (internal) tree of anodes
+						   0 -> (leaf) list of extents */
   u8 fill[3];
   u8 n_free_nodes;			/* free nodes in following array */
   u8 n_used_nodes;			/* used nodes in following array */
-  u16 first_free;			/* offset from start of header to
+  __le16 first_free;			/* offset from start of header to
 					   first free node in array */
   union {
     struct bplus_internal_node internal[0]; /* (internal) 2-word entries giving
@@ -428,6 +414,16 @@ struct bplus_header
   } u;
 };
 
+static inline bool bp_internal(struct bplus_header *bp)
+{
+	return bp->flags & BP_internal;
+}
+
+static inline bool bp_fnode_parent(struct bplus_header *bp)
+{
+	return bp->flags & BP_fnode_parent;
+}
+
 /* fnode: root of allocation b+ tree, and EA's */
 
 /* Every file and every directory has one fnode, pointed to by the directory

fs/hpfs/map.c

@@ -132,14 +132,14 @@ struct fnode *hpfs_map_fnode(struct super_block *s, ino_t ino, struct buffer_hea
 			}
 			if (!fnode_is_dir(fnode)) {
 				if ((unsigned)fnode->btree.n_used_nodes + (unsigned)fnode->btree.n_free_nodes !=
-				    (fnode->btree.internal ? 12 : 8)) {
+				    (bp_internal(&fnode->btree) ? 12 : 8)) {
 					hpfs_error(s,
 					   "bad number of nodes in fnode %08lx",
 					    (unsigned long)ino);
 					goto bail;
 				}
 				if (le16_to_cpu(fnode->btree.first_free) !=
-				    8 + fnode->btree.n_used_nodes * (fnode->btree.internal ? 8 : 12)) {
+				    8 + fnode->btree.n_used_nodes * (bp_internal(&fnode->btree) ? 8 : 12)) {
 					hpfs_error(s,
 					    "bad first_free pointer in fnode %08lx",
 					    (unsigned long)ino);
@@ -187,12 +187,12 @@ struct anode *hpfs_map_anode(struct super_block *s, anode_secno ano, struct buff
 				goto bail;
 			}
 			if ((unsigned)anode->btree.n_used_nodes + (unsigned)anode->btree.n_free_nodes !=
-			    (anode->btree.internal ? 60 : 40)) {
+			    (bp_internal(&anode->btree) ? 60 : 40)) {
 				hpfs_error(s, "bad number of nodes in anode %08x", ano);
 				goto bail;
 			}
 			if (le16_to_cpu(anode->btree.first_free) !=
-			    8 + anode->btree.n_used_nodes * (anode->btree.internal ? 8 : 12)) {
+			    8 + anode->btree.n_used_nodes * (bp_internal(&anode->btree) ? 8 : 12)) {
 				hpfs_error(s, "bad first_free pointer in anode %08x", ano);
 				goto bail;
 			}