Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ryusuke/nilfs2:
  nilfs2: fix possible mismatch of sufile counters on recovery
  nilfs2: segment usage file cleanups
  nilfs2: fix wrong accounting and duplicate brelse in nilfs_sufile_set_error
  nilfs2: simplify handling of active state of segments fix
  nilfs2: remove module version
  nilfs2: fix lockdep recursive locking warning on meta data files
  nilfs2: fix lockdep recursive locking warning on bmap
  nilfs2: return f_fsid for statfs2
diff --git a/fs/nilfs2/bmap.c b/fs/nilfs2/bmap.c
index 24638e0..064279e 100644
--- a/fs/nilfs2/bmap.c
+++ b/fs/nilfs2/bmap.c
@@ -688,6 +688,8 @@
 	.bpop_translate		=	NULL,
 };
 
+static struct lock_class_key nilfs_bmap_dat_lock_key;
+
 /**
  * nilfs_bmap_read - read a bmap from an inode
  * @bmap: bmap
@@ -715,6 +717,7 @@
 		bmap->b_pops = &nilfs_bmap_ptr_ops_p;
 		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
 		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:
@@ -772,6 +775,7 @@
 {
 	memcpy(gcbmap, bmap, sizeof(union nilfs_bmap_union));
 	init_rwsem(&gcbmap->b_sem);
+	lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 	gcbmap->b_inode = &NILFS_BMAP_I(gcbmap)->vfs_inode;
 }
 
@@ -779,5 +783,6 @@
 {
 	memcpy(bmap, gcbmap, sizeof(union nilfs_bmap_union));
 	init_rwsem(&bmap->b_sem);
+	lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
 }
diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 7558c97..3d0c18a 100644
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -35,11 +35,6 @@
 #include "bmap_union.h"
 
 /*
- * NILFS filesystem version
- */
-#define NILFS_VERSION		"2.0.5"
-
-/*
  * nilfs inode data in memory
  */
 struct nilfs_inode_info {
diff --git a/fs/nilfs2/recovery.c b/fs/nilfs2/recovery.c
index 6ade096..4fc081e 100644
--- a/fs/nilfs2/recovery.c
+++ b/fs/nilfs2/recovery.c
@@ -413,7 +413,6 @@
 	struct nilfs_segment_entry *ent, *n;
 	struct inode *sufile = nilfs->ns_sufile;
 	__u64 segnum[4];
-	time_t mtime;
 	int err;
 	int i;
 
@@ -442,24 +441,13 @@
 	 * Collecting segments written after the latest super root.
 	 * These are marked dirty to avoid being reallocated in the next write.
 	 */
-	mtime = get_seconds();
 	list_for_each_entry_safe(ent, n, head, list) {
-		if (ent->segnum == segnum[0]) {
-			list_del(&ent->list);
-			nilfs_free_segment_entry(ent);
-			continue;
-		}
-		err = nilfs_open_segment_entry(ent, sufile);
-		if (unlikely(err))
-			goto failed;
-		if (!nilfs_segment_usage_dirty(ent->raw_su)) {
-			/* make the segment garbage */
-			ent->raw_su->su_nblocks = cpu_to_le32(0);
-			ent->raw_su->su_lastmod = cpu_to_le32(mtime);
-			nilfs_segment_usage_set_dirty(ent->raw_su);
+		if (ent->segnum != segnum[0]) {
+			err = nilfs_sufile_scrap(sufile, ent->segnum);
+			if (unlikely(err))
+				goto failed;
 		}
 		list_del(&ent->list);
-		nilfs_close_segment_entry(ent, sufile);
 		nilfs_free_segment_entry(ent);
 	}
 
diff --git a/fs/nilfs2/sufile.c b/fs/nilfs2/sufile.c
index c774cf3..98e6867 100644
--- a/fs/nilfs2/sufile.c
+++ b/fs/nilfs2/sufile.c
@@ -93,6 +93,52 @@
 				   create, NULL, bhp);
 }
 
+static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
+				     u64 ncleanadd, u64 ndirtyadd)
+{
+	struct nilfs_sufile_header *header;
+	void *kaddr;
+
+	kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
+	header = kaddr + bh_offset(header_bh);
+	le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
+	le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
+	kunmap_atomic(kaddr, KM_USER0);
+
+	nilfs_mdt_mark_buffer_dirty(header_bh);
+}
+
+int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
+			void (*dofunc)(struct inode *, __u64,
+				       struct buffer_head *,
+				       struct buffer_head *))
+{
+	struct buffer_head *header_bh, *bh;
+	int ret;
+
+	if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
+		printk(KERN_WARNING "%s: invalid segment number: %llu\n",
+		       __func__, (unsigned long long)segnum);
+		return -EINVAL;
+	}
+	down_write(&NILFS_MDT(sufile)->mi_sem);
+
+	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
+	if (ret < 0)
+		goto out_sem;
+
+	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
+	if (!ret) {
+		dofunc(sufile, segnum, header_bh, bh);
+		brelse(bh);
+	}
+	brelse(header_bh);
+
+ out_sem:
+	up_write(&NILFS_MDT(sufile)->mi_sem);
+	return ret;
+}
+
 /**
  * nilfs_sufile_alloc - allocate a segment
  * @sufile: inode of segment usage file
@@ -113,7 +159,6 @@
 int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
 {
 	struct buffer_head *header_bh, *su_bh;
-	struct the_nilfs *nilfs;
 	struct nilfs_sufile_header *header;
 	struct nilfs_segment_usage *su;
 	size_t susz = NILFS_MDT(sufile)->mi_entry_size;
@@ -124,8 +169,6 @@
 
 	down_write(&NILFS_MDT(sufile)->mi_sem);
 
-	nilfs = NILFS_MDT(sufile)->mi_nilfs;
-
 	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
 	if (ret < 0)
 		goto out_sem;
@@ -192,165 +235,84 @@
 	return ret;
 }
 
-/**
- * nilfs_sufile_cancel_free -
- * @sufile: inode of segment usage file
- * @segnum: segment number
- *
- * Description:
- *
- * Return Value: On success, 0 is returned. On error, one of the following
- * negative error codes is returned.
- *
- * %-EIO - I/O error.
- *
- * %-ENOMEM - Insufficient amount of memory available.
- */
-int nilfs_sufile_cancel_free(struct inode *sufile, __u64 segnum)
+void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
+				 struct buffer_head *header_bh,
+				 struct buffer_head *su_bh)
 {
-	struct buffer_head *header_bh, *su_bh;
-	struct the_nilfs *nilfs;
-	struct nilfs_sufile_header *header;
 	struct nilfs_segment_usage *su;
 	void *kaddr;
-	int ret;
-
-	down_write(&NILFS_MDT(sufile)->mi_sem);
-
-	nilfs = NILFS_MDT(sufile)->mi_nilfs;
-
-	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
-	if (ret < 0)
-		goto out_sem;
-
-	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &su_bh);
-	if (ret < 0)
-		goto out_header;
 
 	kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
-	su = nilfs_sufile_block_get_segment_usage(
-		sufile, segnum, su_bh, kaddr);
+	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 	if (unlikely(!nilfs_segment_usage_clean(su))) {
 		printk(KERN_WARNING "%s: segment %llu must be clean\n",
 		       __func__, (unsigned long long)segnum);
 		kunmap_atomic(kaddr, KM_USER0);
-		goto out_su_bh;
+		return;
 	}
 	nilfs_segment_usage_set_dirty(su);
 	kunmap_atomic(kaddr, KM_USER0);
 
-	kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
-	header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
-	le64_add_cpu(&header->sh_ncleansegs, -1);
-	le64_add_cpu(&header->sh_ndirtysegs, 1);
-	kunmap_atomic(kaddr, KM_USER0);
-
-	nilfs_mdt_mark_buffer_dirty(header_bh);
+	nilfs_sufile_mod_counter(header_bh, -1, 1);
 	nilfs_mdt_mark_buffer_dirty(su_bh);
 	nilfs_mdt_mark_dirty(sufile);
-
- out_su_bh:
-	brelse(su_bh);
- out_header:
-	brelse(header_bh);
- out_sem:
-	up_write(&NILFS_MDT(sufile)->mi_sem);
-	return ret;
 }
 
-/**
- * nilfs_sufile_freev - free segments
- * @sufile: inode of segment usage file
- * @segnum: array of segment numbers
- * @nsegs: number of segments
- *
- * Description: nilfs_sufile_freev() frees segments specified by @segnum and
- * @nsegs, which must have been returned by a previous call to
- * nilfs_sufile_alloc().
- *
- * Return Value: On success, 0 is returned. On error, one of the following
- * negative error codes is returned.
- *
- * %-EIO - I/O error.
- *
- * %-ENOMEM - Insufficient amount of memory available.
- */
-#define NILFS_SUFILE_FREEV_PREALLOC	16
-int nilfs_sufile_freev(struct inode *sufile, __u64 *segnum, size_t nsegs)
+void nilfs_sufile_do_scrap(struct inode *sufile, __u64 segnum,
+			   struct buffer_head *header_bh,
+			   struct buffer_head *su_bh)
 {
-	struct buffer_head *header_bh, **su_bh,
-		*su_bh_prealloc[NILFS_SUFILE_FREEV_PREALLOC];
-	struct the_nilfs *nilfs;
-	struct nilfs_sufile_header *header;
 	struct nilfs_segment_usage *su;
 	void *kaddr;
-	int ret, i;
+	int clean, dirty;
 
-	down_write(&NILFS_MDT(sufile)->mi_sem);
-
-	nilfs = NILFS_MDT(sufile)->mi_nilfs;
-
-	/* prepare resources */
-	if (nsegs <= NILFS_SUFILE_FREEV_PREALLOC)
-		su_bh = su_bh_prealloc;
-	else {
-		su_bh = kmalloc(sizeof(*su_bh) * nsegs, GFP_NOFS);
-		if (su_bh == NULL) {
-			ret = -ENOMEM;
-			goto out_sem;
-		}
-	}
-
-	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
-	if (ret < 0)
-		goto out_su_bh;
-	for (i = 0; i < nsegs; i++) {
-		ret = nilfs_sufile_get_segment_usage_block(sufile, segnum[i],
-							   0, &su_bh[i]);
-		if (ret < 0)
-			goto out_bh;
-	}
-
-	/* free segments */
-	for (i = 0; i < nsegs; i++) {
-		kaddr = kmap_atomic(su_bh[i]->b_page, KM_USER0);
-		su = nilfs_sufile_block_get_segment_usage(
-			sufile, segnum[i], su_bh[i], kaddr);
-		WARN_ON(nilfs_segment_usage_error(su));
-		nilfs_segment_usage_set_clean(su);
+	kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
+	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
+	if (su->su_flags == cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY) &&
+	    su->su_nblocks == cpu_to_le32(0)) {
 		kunmap_atomic(kaddr, KM_USER0);
-		nilfs_mdt_mark_buffer_dirty(su_bh[i]);
+		return;
 	}
-	kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
-	header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
-	le64_add_cpu(&header->sh_ncleansegs, nsegs);
-	le64_add_cpu(&header->sh_ndirtysegs, -(u64)nsegs);
+	clean = nilfs_segment_usage_clean(su);
+	dirty = nilfs_segment_usage_dirty(su);
+
+	/* make the segment garbage */
+	su->su_lastmod = cpu_to_le64(0);
+	su->su_nblocks = cpu_to_le32(0);
+	su->su_flags = cpu_to_le32(1UL << NILFS_SEGMENT_USAGE_DIRTY);
 	kunmap_atomic(kaddr, KM_USER0);
-	nilfs_mdt_mark_buffer_dirty(header_bh);
+
+	nilfs_sufile_mod_counter(header_bh, clean ? (u64)-1 : 0, dirty ? 0 : 1);
+	nilfs_mdt_mark_buffer_dirty(su_bh);
 	nilfs_mdt_mark_dirty(sufile);
-
- out_bh:
-	for (i--; i >= 0; i--)
-		brelse(su_bh[i]);
-	brelse(header_bh);
-
- out_su_bh:
-	if (su_bh != su_bh_prealloc)
-		kfree(su_bh);
-
- out_sem:
-	up_write(&NILFS_MDT(sufile)->mi_sem);
-	return ret;
 }
 
-/**
- * nilfs_sufile_free -
- * @sufile:
- * @segnum:
- */
-int nilfs_sufile_free(struct inode *sufile, __u64 segnum)
+void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
+			  struct buffer_head *header_bh,
+			  struct buffer_head *su_bh)
 {
-	return nilfs_sufile_freev(sufile, &segnum, 1);
+	struct nilfs_segment_usage *su;
+	void *kaddr;
+	int sudirty;
+
+	kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
+	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
+	if (nilfs_segment_usage_clean(su)) {
+		printk(KERN_WARNING "%s: segment %llu is already clean\n",
+		       __func__, (unsigned long long)segnum);
+		kunmap_atomic(kaddr, KM_USER0);
+		return;
+	}
+	WARN_ON(nilfs_segment_usage_error(su));
+	WARN_ON(!nilfs_segment_usage_dirty(su));
+
+	sudirty = nilfs_segment_usage_dirty(su);
+	nilfs_segment_usage_set_clean(su);
+	kunmap_atomic(kaddr, KM_USER0);
+	nilfs_mdt_mark_buffer_dirty(su_bh);
+
+	nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
+	nilfs_mdt_mark_dirty(sufile);
 }
 
 /**
@@ -500,72 +462,28 @@
 	return ret;
 }
 
-/**
- * nilfs_sufile_set_error - mark a segment as erroneous
- * @sufile: inode of segment usage file
- * @segnum: segment number
- *
- * Description: nilfs_sufile_set_error() marks the segment specified by
- * @segnum as erroneous. The error segment will never be used again.
- *
- * Return Value: On success, 0 is returned. On error, one of the following
- * negative error codes is returned.
- *
- * %-EIO - I/O error.
- *
- * %-ENOMEM - Insufficient amount of memory available.
- *
- * %-EINVAL - Invalid segment usage number.
- */
-int nilfs_sufile_set_error(struct inode *sufile, __u64 segnum)
+void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
+			       struct buffer_head *header_bh,
+			       struct buffer_head *su_bh)
 {
-	struct buffer_head *header_bh, *su_bh;
 	struct nilfs_segment_usage *su;
-	struct nilfs_sufile_header *header;
 	void *kaddr;
-	int ret;
-
-	if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
-		printk(KERN_WARNING "%s: invalid segment number: %llu\n",
-		       __func__, (unsigned long long)segnum);
-		return -EINVAL;
-	}
-	down_write(&NILFS_MDT(sufile)->mi_sem);
-
-	ret = nilfs_sufile_get_header_block(sufile, &header_bh);
-	if (ret < 0)
-		goto out_sem;
-	ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &su_bh);
-	if (ret < 0)
-		goto out_header;
+	int suclean;
 
 	kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
 	su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
 	if (nilfs_segment_usage_error(su)) {
 		kunmap_atomic(kaddr, KM_USER0);
-		brelse(su_bh);
-		goto out_header;
+		return;
 	}
-
+	suclean = nilfs_segment_usage_clean(su);
 	nilfs_segment_usage_set_error(su);
 	kunmap_atomic(kaddr, KM_USER0);
-	brelse(su_bh);
 
-	kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
-	header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
-	le64_add_cpu(&header->sh_ndirtysegs, -1);
-	kunmap_atomic(kaddr, KM_USER0);
-	nilfs_mdt_mark_buffer_dirty(header_bh);
+	if (suclean)
+		nilfs_sufile_mod_counter(header_bh, -1, 0);
 	nilfs_mdt_mark_buffer_dirty(su_bh);
 	nilfs_mdt_mark_dirty(sufile);
-	brelse(su_bh);
-
- out_header:
-	brelse(header_bh);
-
- out_sem:
-	up_write(&NILFS_MDT(sufile)->mi_sem);
-	return ret;
 }
 
 /**
@@ -625,7 +543,7 @@
 			si[i + j].sui_nblocks = le32_to_cpu(su->su_nblocks);
 			si[i + j].sui_flags = le32_to_cpu(su->su_flags) &
 				~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
-			if (nilfs_segment_is_active(nilfs, segnum + i + j))
+			if (nilfs_segment_is_active(nilfs, segnum + j))
 				si[i + j].sui_flags |=
 					(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
 		}
diff --git a/fs/nilfs2/sufile.h b/fs/nilfs2/sufile.h
index d595f33..a2e2efd 100644
--- a/fs/nilfs2/sufile.h
+++ b/fs/nilfs2/sufile.h
@@ -36,9 +36,6 @@
 }
 
 int nilfs_sufile_alloc(struct inode *, __u64 *);
-int nilfs_sufile_cancel_free(struct inode *, __u64);
-int nilfs_sufile_freev(struct inode *, __u64 *, size_t);
-int nilfs_sufile_free(struct inode *, __u64);
 int nilfs_sufile_get_segment_usage(struct inode *, __u64,
 				   struct nilfs_segment_usage **,
 				   struct buffer_head **);
@@ -46,9 +43,83 @@
 				    struct buffer_head *);
 int nilfs_sufile_get_stat(struct inode *, struct nilfs_sustat *);
 int nilfs_sufile_get_ncleansegs(struct inode *, unsigned long *);
-int nilfs_sufile_set_error(struct inode *, __u64);
 ssize_t nilfs_sufile_get_suinfo(struct inode *, __u64, struct nilfs_suinfo *,
 				size_t);
 
+int nilfs_sufile_update(struct inode *, __u64, int,
+			void (*dofunc)(struct inode *, __u64,
+				       struct buffer_head *,
+				       struct buffer_head *));
+void nilfs_sufile_do_cancel_free(struct inode *, __u64, struct buffer_head *,
+				 struct buffer_head *);
+void nilfs_sufile_do_scrap(struct inode *, __u64, struct buffer_head *,
+			   struct buffer_head *);
+void nilfs_sufile_do_free(struct inode *, __u64, struct buffer_head *,
+			  struct buffer_head *);
+void nilfs_sufile_do_set_error(struct inode *, __u64, struct buffer_head *,
+			       struct buffer_head *);
+
+/**
+ * nilfs_sufile_cancel_free -
+ * @sufile: inode of segment usage file
+ * @segnum: segment number
+ *
+ * Description:
+ *
+ * Return Value: On success, 0 is returned. On error, one of the following
+ * negative error codes is returned.
+ *
+ * %-EIO - I/O error.
+ *
+ * %-ENOMEM - Insufficient amount of memory available.
+ */
+static inline int nilfs_sufile_cancel_free(struct inode *sufile, __u64 segnum)
+{
+	return nilfs_sufile_update(sufile, segnum, 0,
+				   nilfs_sufile_do_cancel_free);
+}
+
+/**
+ * nilfs_sufile_scrap - make a segment garbage
+ * @sufile: inode of segment usage file
+ * @segnum: segment number to be freed
+ */
+static inline int nilfs_sufile_scrap(struct inode *sufile, __u64 segnum)
+{
+	return nilfs_sufile_update(sufile, segnum, 1, nilfs_sufile_do_scrap);
+}
+
+/**
+ * nilfs_sufile_free - free segment
+ * @sufile: inode of segment usage file
+ * @segnum: segment number to be freed
+ */
+static inline int nilfs_sufile_free(struct inode *sufile, __u64 segnum)
+{
+	return nilfs_sufile_update(sufile, segnum, 0, nilfs_sufile_do_free);
+}
+
+/**
+ * nilfs_sufile_set_error - mark a segment as erroneous
+ * @sufile: inode of segment usage file
+ * @segnum: segment number
+ *
+ * Description: nilfs_sufile_set_error() marks the segment specified by
+ * @segnum as erroneous. The error segment will never be used again.
+ *
+ * Return Value: On success, 0 is returned. On error, one of the following
+ * negative error codes is returned.
+ *
+ * %-EIO - I/O error.
+ *
+ * %-ENOMEM - Insufficient amount of memory available.
+ *
+ * %-EINVAL - Invalid segment usage number.
+ */
+static inline int nilfs_sufile_set_error(struct inode *sufile, __u64 segnum)
+{
+	return nilfs_sufile_update(sufile, segnum, 0,
+				   nilfs_sufile_do_set_error);
+}
 
 #endif	/* _NILFS_SUFILE_H */
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index e117e1e..6989b03 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -63,7 +63,6 @@
 MODULE_AUTHOR("NTT Corp.");
 MODULE_DESCRIPTION("A New Implementation of the Log-structured Filesystem "
 		   "(NILFS)");
-MODULE_VERSION(NILFS_VERSION);
 MODULE_LICENSE("GPL");
 
 static int nilfs_remount(struct super_block *sb, int *flags, char *data);
@@ -476,11 +475,12 @@
 {
 	struct super_block *sb = dentry->d_sb;
 	struct nilfs_sb_info *sbi = NILFS_SB(sb);
+	struct the_nilfs *nilfs = sbi->s_nilfs;
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
 	unsigned long long blocks;
 	unsigned long overhead;
 	unsigned long nrsvblocks;
 	sector_t nfreeblocks;
-	struct the_nilfs *nilfs = sbi->s_nilfs;
 	int err;
 
 	/*
@@ -514,6 +514,9 @@
 	buf->f_files = atomic_read(&sbi->s_inodes_count);
 	buf->f_ffree = 0; /* nilfs_count_free_inodes(sb); */
 	buf->f_namelen = NILFS_NAME_LEN;
+	buf->f_fsid.val[0] = (u32)id;
+	buf->f_fsid.val[1] = (u32)(id >> 32);
+
 	return 0;
 }
 
diff --git a/fs/nilfs2/the_nilfs.c b/fs/nilfs2/the_nilfs.c
index 33400cf..7f65b3b 100644
--- a/fs/nilfs2/the_nilfs.c
+++ b/fs/nilfs2/the_nilfs.c
@@ -115,6 +115,7 @@
 static int nilfs_load_super_root(struct the_nilfs *nilfs,
 				 struct nilfs_sb_info *sbi, sector_t sr_block)
 {
+	static struct lock_class_key dat_lock_key;
 	struct buffer_head *bh_sr;
 	struct nilfs_super_root *raw_sr;
 	struct nilfs_super_block **sbp = nilfs->ns_sbp;
@@ -163,6 +164,9 @@
 	if (unlikely(err))
 		goto failed_sufile;
 
+	lockdep_set_class(&NILFS_MDT(nilfs->ns_dat)->mi_sem, &dat_lock_key);
+	lockdep_set_class(&NILFS_MDT(nilfs->ns_gc_dat)->mi_sem, &dat_lock_key);
+
 	nilfs_mdt_set_shadow(nilfs->ns_dat, nilfs->ns_gc_dat);
 	nilfs_mdt_set_entry_size(nilfs->ns_cpfile, checkpoint_size,
 				 sizeof(struct nilfs_cpfile_header));