1 files changed, 101 insertions, 317 deletions

diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c
index 24638e059bf..aadbd0b5e3e 100644
--- a/fs/nilfs2/bmap.c
+++ b/fs/nilfs2/bmap.c
@@ -25,46 +25,45 @@
 #include <linux/errno.h>
 #include "nilfs.h"
 #include "bmap.h"
-#include "sb.h"
+#include "btree.h"
+#include "direct.h"
 #include "btnode.h"
 #include "mdt.h"
 #include "dat.h"
 #include "alloc.h"
 
-int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
-			       __u64 *ptrp)
+struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
 {
-	__u64 ptr;
-	int ret;
-
-	down_read(&bmap->b_sem);
-	ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
-	if (ret < 0)
-		goto out;
-	if (bmap->b_pops->bpop_translate != NULL) {
-		ret = bmap->b_pops->bpop_translate(bmap, *ptrp, &ptr);
-		if (ret < 0)
-			goto out;
-		*ptrp = ptr;
-	}
+	struct the_nilfs *nilfs = bmap->b_inode->i_sb->s_fs_info;
 
- out:
-	up_read(&bmap->b_sem);
-	return ret;
+	return nilfs->ns_dat;
 }
 
+static int nilfs_bmap_convert_error(struct nilfs_bmap *bmap,
+				     const char *fname, int err)
+{
+	struct inode *inode = bmap->b_inode;
+
+	if (err == -EINVAL) {
+		nilfs_error(inode->i_sb, fname,
+			    "broken bmap (inode number=%lu)\n", inode->i_ino);
+		err = -EIO;
+	}
+	return err;
+}
 
 /**
- * nilfs_bmap_lookup - find a record
+ * nilfs_bmap_lookup_at_level - find a data block or node block
  * @bmap: bmap
  * @key: key
- * @recp: pointer to record
+ * @level: level
+ * @ptrp: place to store the value associated to @key
  *
- * Description: nilfs_bmap_lookup() finds a record whose key matches @key in
- * @bmap.
+ * Description: nilfs_bmap_lookup_at_level() finds a record whose key
+ * matches @key in the block at @level of the bmap.
  *
  * Return Value: On success, 0 is returned and the record associated with @key
- * is stored in the place pointed by @recp. On error, one of the following
+ * is stored in the place pointed by @ptrp. On error, one of the following
  * negative error codes is returned.
  *
  * %-EIO - I/O error.
@@ -73,20 +72,42 @@ int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
  *
  * %-ENOENT - A record associated with @key does not exist.
  */
-int nilfs_bmap_lookup(struct nilfs_bmap *bmap,
-		      unsigned long key,
-		      unsigned long *recp)
+int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
+			       __u64 *ptrp)
 {
-	__u64 ptr;
+	sector_t blocknr;
 	int ret;
 
-	/* XXX: use macro for level 1 */
-	ret = nilfs_bmap_lookup_at_level(bmap, key, 1, &ptr);
-	if (recp != NULL)
-		*recp = ptr;
+	down_read(&bmap->b_sem);
+	ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
+	if (ret < 0) {
+		ret = nilfs_bmap_convert_error(bmap, __func__, ret);
+		goto out;
+	}
+	if (NILFS_BMAP_USE_VBN(bmap)) {
+		ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
+					  &blocknr);
+		if (!ret)
+			*ptrp = blocknr;
+	}
+
+ out:
+	up_read(&bmap->b_sem);
 	return ret;
 }
 
+int nilfs_bmap_lookup_contig(struct nilfs_bmap *bmap, __u64 key, __u64 *ptrp,
+			     unsigned maxblocks)
+{
+	int ret;
+
+	down_read(&bmap->b_sem);
+	ret = bmap->b_ops->bop_lookup_contig(bmap, key, ptrp, maxblocks);
+	up_read(&bmap->b_sem);
+
+	return nilfs_bmap_convert_error(bmap, __func__, ret);
+}
+
 static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 {
 	__u64 keys[NILFS_BMAP_SMALL_HIGH + 1];
@@ -101,8 +122,7 @@ static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
 			if (n < 0)
 				return n;
 			ret = nilfs_btree_convert_and_insert(
-				bmap, key, ptr, keys, ptrs, n,
-				NILFS_BMAP_LARGE_LOW, NILFS_BMAP_LARGE_HIGH);
+				bmap, key, ptr, keys, ptrs, n);
 			if (ret == 0)
 				bmap->b_u.u_flags |= NILFS_BMAP_LARGE;
 
@@ -141,7 +161,8 @@ int nilfs_bmap_insert(struct nilfs_bmap *bmap,
 	down_write(&bmap->b_sem);
 	ret = nilfs_bmap_do_insert(bmap, key, rec);
 	up_write(&bmap->b_sem);
-	return ret;
+
+	return nilfs_bmap_convert_error(bmap, __func__, ret);
 }
 
 static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
@@ -158,8 +179,7 @@ static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
 			if (n < 0)
 				return n;
 			ret = nilfs_direct_delete_and_convert(
-				bmap, key, keys, ptrs, n,
-				NILFS_BMAP_SMALL_LOW, NILFS_BMAP_SMALL_HIGH);
+				bmap, key, keys, ptrs, n);
 			if (ret == 0)
 				bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;
 
@@ -178,9 +198,12 @@ int nilfs_bmap_last_key(struct nilfs_bmap *bmap, unsigned long *key)
 
 	down_read(&bmap->b_sem);
 	ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
-	if (!ret)
-		*key = lastkey;
 	up_read(&bmap->b_sem);
+
+	if (ret < 0)
+		ret = nilfs_bmap_convert_error(bmap, __func__, ret);
+	else
+		*key = lastkey;
 	return ret;
 }
 
@@ -208,7 +231,8 @@ int nilfs_bmap_delete(struct nilfs_bmap *bmap, unsigned long key)
 	down_write(&bmap->b_sem);
 	ret = nilfs_bmap_do_delete(bmap, key);
 	up_write(&bmap->b_sem);
-	return ret;
+
+	return nilfs_bmap_convert_error(bmap, __func__, ret);
 }
 
 static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, unsigned long key)
@@ -259,7 +283,8 @@ int nilfs_bmap_truncate(struct nilfs_bmap *bmap, unsigned long key)
 	down_write(&bmap->b_sem);
 	ret = nilfs_bmap_do_truncate(bmap, key);
 	up_write(&bmap->b_sem);
-	return ret;
+
+	return nilfs_bmap_convert_error(bmap, __func__, ret);
 }
 
 /**
@@ -298,7 +323,8 @@ int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
 	down_write(&bmap->b_sem);
 	ret = bmap->b_ops->bop_propagate(bmap, bh);
 	up_write(&bmap->b_sem);
-	return ret;
+
+	return nilfs_bmap_convert_error(bmap, __func__, ret);
 }
 
 /**
@@ -342,7 +368,8 @@ int nilfs_bmap_assign(struct nilfs_bmap *bmap,
 	down_write(&bmap->b_sem);
 	ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
 	up_write(&bmap->b_sem);
-	return ret;
+
+	return nilfs_bmap_convert_error(bmap, __func__, ret);
 }
 
 /**
@@ -371,7 +398,8 @@ int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
 	down_write(&bmap->b_sem);
 	ret = bmap->b_ops->bop_mark(bmap, key, level);
 	up_write(&bmap->b_sem);
-	return ret;
+
+	return nilfs_bmap_convert_error(bmap, __func__, ret);
 }
 
 /**
@@ -398,57 +426,6 @@ int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
 /*
  * Internal use only
  */
-
-void nilfs_bmap_add_blocks(const struct nilfs_bmap *bmap, int n)
-{
-	inode_add_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
-	if (NILFS_MDT(bmap->b_inode))
-		nilfs_mdt_mark_dirty(bmap->b_inode);
-	else
-		mark_inode_dirty(bmap->b_inode);
-}
-
-void nilfs_bmap_sub_blocks(const struct nilfs_bmap *bmap, int n)
-{
-	inode_sub_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
-	if (NILFS_MDT(bmap->b_inode))
-		nilfs_mdt_mark_dirty(bmap->b_inode);
-	else
-		mark_inode_dirty(bmap->b_inode);
-}
-
-int nilfs_bmap_get_block(const struct nilfs_bmap *bmap, __u64 ptr,
-			 struct buffer_head **bhp)
-{
-	return nilfs_btnode_get(&NILFS_BMAP_I(bmap)->i_btnode_cache,
-				ptr, 0, bhp, 0);
-}
-
-void nilfs_bmap_put_block(const struct nilfs_bmap *bmap,
-			  struct buffer_head *bh)
-{
-	brelse(bh);
-}
-
-int nilfs_bmap_get_new_block(const struct nilfs_bmap *bmap, __u64 ptr,
-			     struct buffer_head **bhp)
-{
-	int ret;
-
-	ret = nilfs_btnode_get(&NILFS_BMAP_I(bmap)->i_btnode_cache,
-			       ptr, 0, bhp, 1);
-	if (ret < 0)
-		return ret;
-	set_buffer_nilfs_volatile(*bhp);
-	return 0;
-}
-
-void nilfs_bmap_delete_block(const struct nilfs_bmap *bmap,
-			     struct buffer_head *bh)
-{
-	nilfs_btnode_delete(bh);
-}
-
 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
 			      const struct buffer_head *bh)
 {
@@ -457,8 +434,8 @@ __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
 
 	key = page_index(bh->b_page) << (PAGE_CACHE_SHIFT -
 					 bmap->b_inode->i_blkbits);
-	for (pbh = page_buffers(bh->b_page); pbh != bh;
-	     pbh = pbh->b_this_page, key++);
+	for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page)
+		key++;
 
 	return key;
 }
@@ -476,11 +453,6 @@ __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
 		return NILFS_BMAP_INVALID_PTR;
 }
 
-static struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
-{
-	return nilfs_dat_inode(NILFS_I_NILFS(bmap->b_inode));
-}
-
 #define NILFS_BMAP_GROUP_DIV	8
 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
 {
@@ -493,200 +465,8 @@ __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
 		(entries_per_group / NILFS_BMAP_GROUP_DIV);
 }
 
-static int nilfs_bmap_prepare_alloc_v(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req)
-{
-	return nilfs_dat_prepare_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
-}
-
-static void nilfs_bmap_commit_alloc_v(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req)
-{
-	nilfs_dat_commit_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
-}
-
-static void nilfs_bmap_abort_alloc_v(struct nilfs_bmap *bmap,
-				     union nilfs_bmap_ptr_req *req)
-{
-	nilfs_dat_abort_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
-}
-
-static int nilfs_bmap_prepare_start_v(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req)
-{
-	return nilfs_dat_prepare_start(nilfs_bmap_get_dat(bmap), &req->bpr_req);
-}
-
-static void nilfs_bmap_commit_start_v(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req,
-				      sector_t blocknr)
-{
-	nilfs_dat_commit_start(nilfs_bmap_get_dat(bmap), &req->bpr_req,
-			       blocknr);
-}
-
-static void nilfs_bmap_abort_start_v(struct nilfs_bmap *bmap,
-				     union nilfs_bmap_ptr_req *req)
-{
-	nilfs_dat_abort_start(nilfs_bmap_get_dat(bmap), &req->bpr_req);
-}
-
-static int nilfs_bmap_prepare_end_v(struct nilfs_bmap *bmap,
-				    union nilfs_bmap_ptr_req *req)
-{
-	return nilfs_dat_prepare_end(nilfs_bmap_get_dat(bmap), &req->bpr_req);
-}
-
-static void nilfs_bmap_commit_end_v(struct nilfs_bmap *bmap,
-				    union nilfs_bmap_ptr_req *req)
-{
-	nilfs_dat_commit_end(nilfs_bmap_get_dat(bmap), &req->bpr_req, 0);
-}
-
-static void nilfs_bmap_commit_end_vmdt(struct nilfs_bmap *bmap,
-				       union nilfs_bmap_ptr_req *req)
-{
-	nilfs_dat_commit_end(nilfs_bmap_get_dat(bmap), &req->bpr_req, 1);
-}
-
-static void nilfs_bmap_abort_end_v(struct nilfs_bmap *bmap,
-				   union nilfs_bmap_ptr_req *req)
-{
-	nilfs_dat_abort_end(nilfs_bmap_get_dat(bmap), &req->bpr_req);
-}
-
-int nilfs_bmap_move_v(const struct nilfs_bmap *bmap, __u64 vblocknr,
-		      sector_t blocknr)
-{
-	return nilfs_dat_move(nilfs_bmap_get_dat(bmap), vblocknr, blocknr);
-}
-
-int nilfs_bmap_mark_dirty(const struct nilfs_bmap *bmap, __u64 vblocknr)
-{
-	return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(bmap), vblocknr);
-}
-
-int nilfs_bmap_prepare_update(struct nilfs_bmap *bmap,
-			      union nilfs_bmap_ptr_req *oldreq,
-			      union nilfs_bmap_ptr_req *newreq)
-{
-	int ret;
-
-	ret = bmap->b_pops->bpop_prepare_end_ptr(bmap, oldreq);
-	if (ret < 0)
-		return ret;
-	ret = bmap->b_pops->bpop_prepare_alloc_ptr(bmap, newreq);
-	if (ret < 0)
-		bmap->b_pops->bpop_abort_end_ptr(bmap, oldreq);
-
-	return ret;
-}
-
-void nilfs_bmap_commit_update(struct nilfs_bmap *bmap,
-			      union nilfs_bmap_ptr_req *oldreq,
-			      union nilfs_bmap_ptr_req *newreq)
-{
-	bmap->b_pops->bpop_commit_end_ptr(bmap, oldreq);
-	bmap->b_pops->bpop_commit_alloc_ptr(bmap, newreq);
-}
-
-void nilfs_bmap_abort_update(struct nilfs_bmap *bmap,
-			     union nilfs_bmap_ptr_req *oldreq,
-			     union nilfs_bmap_ptr_req *newreq)
-{
-	bmap->b_pops->bpop_abort_end_ptr(bmap, oldreq);
-	bmap->b_pops->bpop_abort_alloc_ptr(bmap, newreq);
-}
-
-static int nilfs_bmap_translate_v(const struct nilfs_bmap *bmap, __u64 ptr,
-				  __u64 *ptrp)
-{
-	sector_t blocknr;
-	int ret;
-
-	ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), ptr, &blocknr);
-	if (ret < 0)
-		return ret;
-	if (ptrp != NULL)
-		*ptrp = blocknr;
-	return 0;
-}
-
-static int nilfs_bmap_prepare_alloc_p(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req)
-{
-	/* ignore target ptr */
-	req->bpr_ptr = bmap->b_last_allocated_ptr++;
-	return 0;
-}
-
-static void nilfs_bmap_commit_alloc_p(struct nilfs_bmap *bmap,
-				      union nilfs_bmap_ptr_req *req)
-{
-	/* do nothing */
-}
-
-static void nilfs_bmap_abort_alloc_p(struct nilfs_bmap *bmap,
-				     union nilfs_bmap_ptr_req *req)
-{
-	bmap->b_last_allocated_ptr--;
-}
-
-static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_v = {
-	.bpop_prepare_alloc_ptr	=	nilfs_bmap_prepare_alloc_v,
-	.bpop_commit_alloc_ptr	=	nilfs_bmap_commit_alloc_v,
-	.bpop_abort_alloc_ptr	=	nilfs_bmap_abort_alloc_v,
-	.bpop_prepare_start_ptr	=	nilfs_bmap_prepare_start_v,
-	.bpop_commit_start_ptr	=	nilfs_bmap_commit_start_v,
-	.bpop_abort_start_ptr	=	nilfs_bmap_abort_start_v,
-	.bpop_prepare_end_ptr	=	nilfs_bmap_prepare_end_v,
-	.bpop_commit_end_ptr	=	nilfs_bmap_commit_end_v,
-	.bpop_abort_end_ptr	=	nilfs_bmap_abort_end_v,
-
-	.bpop_translate		=	nilfs_bmap_translate_v,
-};
-
-static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_vmdt = {
-	.bpop_prepare_alloc_ptr	=	nilfs_bmap_prepare_alloc_v,
-	.bpop_commit_alloc_ptr	=	nilfs_bmap_commit_alloc_v,
-	.bpop_abort_alloc_ptr	=	nilfs_bmap_abort_alloc_v,
-	.bpop_prepare_start_ptr	=	nilfs_bmap_prepare_start_v,
-	.bpop_commit_start_ptr	=	nilfs_bmap_commit_start_v,
-	.bpop_abort_start_ptr	=	nilfs_bmap_abort_start_v,
-	.bpop_prepare_end_ptr	=	nilfs_bmap_prepare_end_v,
-	.bpop_commit_end_ptr	=	nilfs_bmap_commit_end_vmdt,
-	.bpop_abort_end_ptr	=	nilfs_bmap_abort_end_v,
-
-	.bpop_translate		=	nilfs_bmap_translate_v,
-};
-
-static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_p = {
-	.bpop_prepare_alloc_ptr	=	nilfs_bmap_prepare_alloc_p,
-	.bpop_commit_alloc_ptr	=	nilfs_bmap_commit_alloc_p,
-	.bpop_abort_alloc_ptr	=	nilfs_bmap_abort_alloc_p,
-	.bpop_prepare_start_ptr	=	NULL,
-	.bpop_commit_start_ptr	=	NULL,
-	.bpop_abort_start_ptr	=	NULL,
-	.bpop_prepare_end_ptr	=	NULL,
-	.bpop_commit_end_ptr	=	NULL,
-	.bpop_abort_end_ptr	=	NULL,
-
-	.bpop_translate		=	NULL,
-};
-
-static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_gc = {
-	.bpop_prepare_alloc_ptr	=	NULL,
-	.bpop_commit_alloc_ptr	=	NULL,
-	.bpop_abort_alloc_ptr	=	NULL,
-	.bpop_prepare_start_ptr	=	NULL,
-	.bpop_commit_start_ptr	=	NULL,
-	.bpop_abort_start_ptr	=	NULL,
-	.bpop_prepare_end_ptr	=	NULL,
-	.bpop_commit_end_ptr	=	NULL,
-	.bpop_abort_end_ptr	=	NULL,
-
-	.bpop_translate		=	NULL,
-};
+static struct lock_class_key nilfs_bmap_dat_lock_key;
+static struct lock_class_key nilfs_bmap_mdt_lock_key;
 
 /**
  * nilfs_bmap_read - read a bmap from an inode
@@ -712,30 +492,30 @@ int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 	switch (bmap->b_inode->i_ino) {
 	case NILFS_DAT_INO:
-		bmap->b_pops = &nilfs_bmap_ptr_ops_p;
-		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
+		bmap->b_ptr_type = NILFS_BMAP_PTR_P;
+		bmap->b_last_allocated_key = 0;
 		bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
+		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 		break;
 	case NILFS_CPFILE_INO:
 	case NILFS_SUFILE_INO:
-		bmap->b_pops = &nilfs_bmap_ptr_ops_vmdt;
-		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
+		bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
+		bmap->b_last_allocated_key = 0;
 		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
+		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
 		break;
+	case NILFS_IFILE_INO:
+		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
+		/* Fall through */
 	default:
-		bmap->b_pops = &nilfs_bmap_ptr_ops_v;
-		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
+		bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
+		bmap->b_last_allocated_key = 0;
 		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 		break;
 	}
 
 	return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
-		nilfs_btree_init(bmap,
-				 NILFS_BMAP_LARGE_LOW,
-				 NILFS_BMAP_LARGE_HIGH) :
-		nilfs_direct_init(bmap,
-				  NILFS_BMAP_SMALL_LOW,
-				  NILFS_BMAP_SMALL_HIGH);
+		nilfs_btree_init(bmap) : nilfs_direct_init(bmap);
 }
 
 /**
@@ -761,23 +541,27 @@ void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
 	memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
 	init_rwsem(&bmap->b_sem);
 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
-	bmap->b_pops = &nilfs_bmap_ptr_ops_gc;
+	bmap->b_ptr_type = NILFS_BMAP_PTR_U;
 	bmap->b_last_allocated_key = 0;
 	bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
 	bmap->b_state = 0;
 	nilfs_btree_init_gc(bmap);
 }
 
-void nilfs_bmap_init_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
+void nilfs_bmap_save(const struct nilfs_bmap *bmap,
+		     struct nilfs_bmap_store *store)
 {
-	memcpy(gcbmap, bmap, sizeof(union nilfs_bmap_union));
-	init_rwsem(&gcbmap->b_sem);
-	gcbmap->b_inode = &NILFS_BMAP_I(gcbmap)->vfs_inode;
+	memcpy(store->data, bmap->b_u.u_data, sizeof(store->data));
+	store->last_allocated_key = bmap->b_last_allocated_key;
+	store->last_allocated_ptr = bmap->b_last_allocated_ptr;
+	store->state = bmap->b_state;
 }
 
-void nilfs_bmap_commit_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
+void nilfs_bmap_restore(struct nilfs_bmap *bmap,
+			const struct nilfs_bmap_store *store)
 {
-	memcpy(bmap, gcbmap, sizeof(union nilfs_bmap_union));
-	init_rwsem(&bmap->b_sem);
-	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
+	memcpy(bmap->b_u.u_data, store->data, sizeof(store->data));
+	bmap->b_last_allocated_key = store->last_allocated_key;
+	bmap->b_last_allocated_ptr = store->last_allocated_ptr;
+	bmap->b_state = store->state;
 }