Btrfs: get/set for struct header fields

Signed-off-by: NChris Mason <chris.mason@oracle.com>

fs/btrfs/Makefile

@@ -25,7 +25,7 @@ tester: $(objects) random-test.o
 quick-test: $(objects) quick-test.o
 	gcc $(CFLAGS) -o quick-test $(objects) quick-test.o
 
-$(objects) : $(headers)
+$(objects): $(headers)
 
 clean :
 	rm debug-tree tester *.o

fs/btrfs/TODO

 * cleanup, add more error checking, get rid of BUG_ONs
+* endian fixes
 * Make IO functions look more like the page cache
 * Fix ENOSPC handling
 * make blocksize a mkfs parameter instead of #define

fs/btrfs/ctree.h

@@ -35,13 +35,10 @@ struct header {
 	/* generation flags to be added */
 } __attribute__ ((__packed__));
 
+#define MAX_LEVEL 8
 #define NODEPTRS_PER_BLOCK ((CTREE_BLOCKSIZE - sizeof(struct header)) / \
 			    (sizeof(struct key) + sizeof(u64)))
 
-#define MAX_LEVEL 8
-#define node_level(f) ((f) & (MAX_LEVEL-1))
-#define is_leaf(f) (node_level(f) == 0)
-
 struct tree_buffer;
 
 /*
@@ -144,6 +141,64 @@ struct ctree_path {
 	int slots[MAX_LEVEL];
 };
 
+static inline u64 btrfs_header_blocknr(struct header *h)
+{
+	return h->blocknr;
+}
+
+static inline void btrfs_set_header_blocknr(struct header *h, u64 blocknr)
+{
+	h->blocknr = blocknr;
+}
+
+static inline u64 btrfs_header_parentid(struct header *h)
+{
+	return h->parentid;
+}
+
+static inline void btrfs_set_header_parentid(struct header *h, u64 parentid)
+{
+	h->parentid = parentid;
+}
+
+static inline u32 btrfs_header_nritems(struct header *h)
+{
+	return h->nritems;
+}
+
+static inline void btrfs_set_header_nritems(struct header *h, u32 val)
+{
+	h->nritems = val;
+}
+
+static inline u32 btrfs_header_flags(struct header *h)
+{
+	return h->flags;
+}
+
+static inline void btrfs_set_header_flags(struct header *h, u32 val)
+{
+	h->flags = val;
+}
+
+static inline int btrfs_header_level(struct header *h)
+{
+	return btrfs_header_flags(h) & (MAX_LEVEL - 1);
+}
+
+static inline void btrfs_set_header_level(struct header *h, int level)
+{
+	u32 flags;
+	BUG_ON(level > MAX_LEVEL);
+	flags = btrfs_header_flags(h) & ~(MAX_LEVEL - 1);
+	btrfs_set_header_flags(h, flags | level);
+}
+
+static inline int btrfs_is_leaf(struct node *n)
+{
+	return (btrfs_header_level(&n->header) == 0);
+}
+
 struct tree_buffer *alloc_free_block(struct ctree_root *root);
 int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf);
 int free_extent(struct ctree_root *root, u64 blocknr, u64 num_blocks);

fs/btrfs/disk-io.c

@@ -15,9 +15,10 @@ int cache_max = 10000;
 
 static int check_tree_block(struct ctree_root *root, struct tree_buffer *buf)
 {
-	if (buf->blocknr != buf->node.header.blocknr)
+	if (buf->blocknr != btrfs_header_blocknr(&buf->node.header))
 		BUG();
-	if (root->node && buf->node.header.parentid != root->node->node.header.parentid)
+	if (root->node && btrfs_header_parentid(&buf->node.header) !=
+	    btrfs_header_parentid(&root->node->node.header))
 		BUG();
 	return 0;
 }
@@ -129,7 +130,7 @@ int write_tree_block(struct ctree_root *root, struct tree_buffer *buf)
 	loff_t offset = blocknr * CTREE_BLOCKSIZE;
 	int ret;
 
-	if (buf->blocknr != buf->node.header.blocknr)
+	if (buf->blocknr != btrfs_header_blocknr(&buf->node.header))
 		BUG();
 	ret = pwrite(root->fp, &buf->node, CTREE_BLOCKSIZE, offset);
 	if (ret != CTREE_BLOCKSIZE)

fs/btrfs/extent-tree.c

@@ -79,10 +79,10 @@ int btrfs_inc_ref(struct ctree_root *root, struct tree_buffer *buf)
 
 	if (root == root->extent_root)
 		return 0;
-	if (is_leaf(buf->node.header.flags))
+	if (btrfs_is_leaf(&buf->node))
 		return 0;
 
-	for (i = 0; i < buf->node.header.nritems; i++) {
+	for (i = 0; i < btrfs_header_nritems(&buf->node.header); i++) {
 		blocknr = buf->node.blockptrs[i];
 		inc_block_ref(root, blocknr);
 	}
@@ -119,7 +119,8 @@ static int finish_current_insert(struct ctree_root *extent_root)
 	int ret;
 
 	extent_item.refs = 1;
-	extent_item.owner = extent_root->node->node.header.parentid;
+	extent_item.owner =
+		btrfs_header_parentid(&extent_root->node->node.header);
 	ins.offset = 1;
 	ins.flags = 0;
 
@@ -269,7 +270,7 @@ static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
 	struct ctree_root * root = orig_root->extent_root;
 	int total_needed = num_blocks;
 
-	total_needed += (node_level(root->node->node.header.flags) + 1) * 3;
+	total_needed += (btrfs_header_level(&root->node->node.header) + 1) * 3;
 	if (root->last_insert.objectid > search_start)
 		search_start = root->last_insert.objectid;
 check_failed:
@@ -288,7 +289,7 @@ static int find_free_extent(struct ctree_root *orig_root, u64 num_blocks,
 	while (1) {
 		l = &path.nodes[0]->leaf;
 		slot = path.slots[0];
-		if (slot >= l->header.nritems) {
+		if (slot >= btrfs_header_nritems(&l->header)) {
 			ret = next_leaf(root, &path);
 			if (ret == 0)
 				continue;
@@ -404,7 +405,7 @@ struct tree_buffer *alloc_free_block(struct ctree_root *root)
 	struct tree_buffer *buf;
 
 	ret = alloc_extent(root, 1, 0, (unsigned long)-1,
-			   root->node->node.header.parentid,
+			   btrfs_header_parentid(&root->node->node.header),
 			   &ins);
 	if (ret) {
 		BUG();
@@ -429,7 +430,8 @@ int walk_down_tree(struct ctree_root *root, struct ctree_path *path, int *level)
 		goto out;
 	while(*level > 0) {
 		cur = path->nodes[*level];
-		if (path->slots[*level] >= cur->node.header.nritems)
+		if (path->slots[*level] >=
+		    btrfs_header_nritems(&cur->node.header))
 			break;
 		blocknr = cur->node.blockptrs[path->slots[*level]];
 		ret = lookup_block_ref(root, blocknr, &refs);
@@ -444,7 +446,7 @@ int walk_down_tree(struct ctree_root *root, struct ctree_path *path, int *level)
 		if (path->nodes[*level-1])
 			tree_block_release(root, path->nodes[*level-1]);
 		path->nodes[*level-1] = next;
-		*level = node_level(next->node.header.flags);
+		*level = btrfs_header_level(&next->node.header);
 		path->slots[*level] = 0;
 	}
 out:
@@ -463,7 +465,8 @@ int walk_up_tree(struct ctree_root *root, struct ctree_path *path, int *level)
 	int ret;
 	for(i = *level; i < MAX_LEVEL - 1 && path->nodes[i]; i++) {
 		slot = path->slots[i];
-		if (slot < path->nodes[i]->node.header.nritems - 1) {
+		if (slot <
+		    btrfs_header_nritems(&path->nodes[i]->node.header)- 1) {
 			path->slots[i]++;
 			*level = i;
 			return 0;
@@ -489,7 +492,7 @@ int btrfs_drop_snapshot(struct ctree_root *root, struct tree_buffer *snap)
 
 	init_path(&path);
 
-	level = node_level(snap->node.header.flags);
+	level = btrfs_header_level(&snap->node.header);
 	orig_level = level;
 	path.nodes[level] = snap;
 	path.slots[level] = 0;
@@ -509,33 +512,3 @@ int btrfs_drop_snapshot(struct ctree_root *root, struct tree_buffer *snap)
 
 	return 0;
 }
-
-
-#if 0
-int btrfs_drop_snapshot(struct ctree_root *root, struct tree_buffer *snap)
-{
-	int ret;
-	int level;
-	int refs;
-	u64 blocknr = snap->blocknr;
-
-	level = node_level(snap->node.header.flags);
-	ret = lookup_block_ref(root, snap->blocknr, &refs);
-	BUG_ON(ret);
-	if (refs == 1 && level != 0) {
-		struct node *n = &snap->node;
-		struct tree_buffer *b;
-		int i;
-		for (i = 0; i < n->header.nritems; i++) {
-			b = read_tree_block(root, n->blockptrs[i]);
-			/* FIXME, don't recurse here */
-			ret = btrfs_drop_snapshot(root, b);
-			BUG_ON(ret);
-			tree_block_release(root, b);
-		}
-	}
-	ret = free_extent(root, blocknr, 1);
-	BUG_ON(ret);
-	return 0;
-}
-#endif

fs/btrfs/mkfs.c

@@ -34,15 +34,15 @@ int mkfs(int fd)
 
 	/* create leaves for the tree root and extent root */
 	memset(&empty_leaf, 0, sizeof(empty_leaf));
-	empty_leaf.header.parentid = 1;
-	empty_leaf.header.blocknr = 17;
+	btrfs_set_header_parentid(&empty_leaf.header, 1);
+	btrfs_set_header_blocknr(&empty_leaf.header, 17);
 	ret = pwrite(fd, &empty_leaf, sizeof(empty_leaf), 17 * CTREE_BLOCKSIZE);
 	if (ret != sizeof(empty_leaf))
 		return -1;
 
-	empty_leaf.header.parentid = 2;
-	empty_leaf.header.blocknr = 18;
-	empty_leaf.header.nritems = 3;
+	btrfs_set_header_parentid(&empty_leaf.header, 2);
+	btrfs_set_header_blocknr(&empty_leaf.header, 18);
+	btrfs_set_header_nritems(&empty_leaf.header, 3);
 
 	/* item1, reserve blocks 0-16 */
 	item.key.objectid = 0;

fs/btrfs/print-tree.c

@@ -8,11 +8,11 @@
 void print_leaf(struct leaf *l)
 {
 	int i;
-	int nr = l->header.nritems;
+	u32 nr = btrfs_header_nritems(&l->header);
 	struct item *item;
 	struct extent_item *ei;
-	printf("leaf %Lu total ptrs %d free space %d\n", l->header.blocknr, nr,
-	       leaf_free_space(l));
+	printf("leaf %Lu total ptrs %d free space %d\n",
+		btrfs_header_blocknr(&l->header), nr, leaf_free_space(l));
 	fflush(stdout);
 	for (i = 0 ; i < nr ; i++) {
 		item = l->items + i;
@@ -32,22 +32,20 @@ void print_leaf(struct leaf *l)
 void print_tree(struct ctree_root *root, struct tree_buffer *t)
 {
 	int i;
-	int nr;
+	u32 nr;
 	struct node *c;
 
 	if (!t)
 		return;
 	c = &t->node;
-	nr = c->header.nritems;
-	if (c->header.blocknr != t->blocknr)
-		BUG();
-	if (is_leaf(c->header.flags)) {
+	nr = btrfs_header_nritems(&c->header);
+	if (btrfs_is_leaf(c)) {
 		print_leaf((struct leaf *)c);
 		return;
 	}
 	printf("node %Lu level %d total ptrs %d free spc %u\n", t->blocknr,
-	        node_level(c->header.flags), c->header.nritems,
-		(u32)NODEPTRS_PER_BLOCK - c->header.nritems);
+	        btrfs_header_level(&c->header), nr,
+		(u32)NODEPTRS_PER_BLOCK - nr);
 	fflush(stdout);
 	for (i = 0; i < nr; i++) {
 		printf("\tkey %d (%Lu %u %Lu) block %Lu\n",
@@ -60,11 +58,11 @@ void print_tree(struct ctree_root *root, struct tree_buffer *t)
 		struct tree_buffer *next_buf = read_tree_block(root,
 							    c->blockptrs[i]);
 		struct node *next = &next_buf->node;
-		if (is_leaf(next->header.flags) &&
-		    node_level(c->header.flags) != 1)
+		if (btrfs_is_leaf(next) &&
+		    btrfs_header_level(&c->header) != 1)
 			BUG();
-		if (node_level(next->header.flags) !=
-			node_level(c->header.flags) - 1)
+		if (btrfs_header_level(&next->header) !=
+			btrfs_header_level(&c->header) - 1)
 			BUG();
 		print_tree(root, next_buf);
 		tree_block_release(root, next_buf);

fs/btrfs/quick-test.c

@@ -71,9 +71,10 @@ int main(int ac, char **av) {
 	close_ctree(root, &super);
 	root = open_ctree("dbfile", &super);
 	printf("node %p level %d total ptrs %d free spc %lu\n", root->node,
-	        node_level(root->node->node.header.flags),
-		root->node->node.header.nritems,
-		NODEPTRS_PER_BLOCK - root->node->node.header.nritems);
+	        btrfs_header_level(&root->node->node.header),
+		btrfs_header_nritems(&root->node->node.header),
+		NODEPTRS_PER_BLOCK -
+		btrfs_header_nritems(&root->node->node.header));
 	printf("all searches good, deleting some items\n");
 	i = 0;
 	srand(55);
@@ -126,7 +127,8 @@ int main(int ac, char **av) {
 		release_path(root, &path);
 	}
 	printf("starting big long delete run\n");
-	while(root->node && root->node->node.header.nritems > 0) {
+	while(root->node &&
+	      btrfs_header_nritems(&root->node->node.header) > 0) {
 		struct leaf *leaf;
 		int slot;
 		ins.objectid = (u64)-1;
@@ -137,7 +139,7 @@ int main(int ac, char **av) {
 
 		leaf = &path.nodes[0]->leaf;
 		slot = path.slots[0];
-		if (slot != leaf->header.nritems)
+		if (slot != btrfs_header_nritems(&leaf->header))
 			BUG();
 		while(path.slots[0] > 0) {
 			path.slots[0] -= 1;

fs/btrfs/random-test.c

@@ -358,8 +358,8 @@ int main(int ac, char **av)
 		}
 		if (i && i % 5000 == 0) {
 			printf("open & close, root level %d nritems %d\n",
-				node_level(root->node->node.header.flags),
-				root->node->node.header.nritems);
+				btrfs_header_level(&root->node->node.header),
+				btrfs_header_nritems(&root->node->node.header));
 			close_ctree(root, &super);
 			root = open_ctree("dbfile", &super);
 		}