diff --git a/kmod/src/data.c b/kmod/src/data.c
index 78dd74ad..54a1857b 100644
--- a/kmod/src/data.c
+++ b/kmod/src/data.c
@@ -1807,37 +1807,6 @@ int scoutfs_data_wait_check_iov(struct inode *inode, const struct iovec *iov,
 	return ret;
 }
 
-int scoutfs_data_wait_check_iter(struct inode *inode, loff_t pos, struct iov_iter *iter,
-				 u8 sef, u8 op, struct scoutfs_data_wait *dw,
-				 struct scoutfs_lock *lock)
-{
-	size_t count = iov_iter_count(iter);
-	size_t off = iter->iov_offset;
-	const struct iovec *iov;
-	size_t len;
-	int ret = 0;
-
-	for (iov = iter->iov; count > 0; iov++) {
-		len = iov->iov_len - off;
-		if (len == 0)
-			continue;
-
-		/* aren't we waiting on too much data here ? */
-		ret = scoutfs_data_wait_check(inode, pos, len,
-					      sef, op, dw, lock);
-
-		if (ret != 0)
-			break;
-
-
-		pos += len;
-		count -= len;
-		off = 0;
-	}
-
-	return ret;
-}
-
 int scoutfs_data_wait(struct inode *inode, struct scoutfs_data_wait *dw)
 {
 	DECLARE_DATA_WAIT_ROOT(inode->i_sb, rt);
diff --git a/kmod/src/data.h b/kmod/src/data.h
index 1fbfce9b..a34854eb 100644
--- a/kmod/src/data.h
+++ b/kmod/src/data.h
@@ -65,9 +65,6 @@ int scoutfs_data_wait_check_iov(struct inode *inode, const struct iovec *iov,
 				unsigned long nr_segs, loff_t pos, u8 sef,
 				u8 op, struct scoutfs_data_wait *ow,
 				struct scoutfs_lock *lock);
-int scoutfs_data_wait_check_iter(struct inode *inode, loff_t pos, struct iov_iter *iter,
-				 u8 sef, u8 op, struct scoutfs_data_wait *ow,
-				 struct scoutfs_lock *lock);
 bool scoutfs_data_wait_found(struct scoutfs_data_wait *ow);
 int scoutfs_data_wait(struct inode *inode,
 			      struct scoutfs_data_wait *ow);
diff --git a/kmod/src/dir.c b/kmod/src/dir.c
index 357d33c6..4227457f 100644
--- a/kmod/src/dir.c
+++ b/kmod/src/dir.c
@@ -931,7 +931,7 @@ static int scoutfs_unlink(struct inode *dir, struct dentry *dentry)
 	ret = lookup_dirent(sb, scoutfs_ino(dir), dentry->d_name.name, dentry->d_name.len, hash,
 			    &dent, dir_lock);
 	if (ret < 0)
-		goto out;
+		goto unlock;
 
 	if (should_orphan(inode)) {
 		ret = scoutfs_lock_orphan(sb, SCOUTFS_LOCK_WRITE_ONLY, 0, scoutfs_ino(inode),
diff --git a/kmod/src/file.c b/kmod/src/file.c
index fd31a9d0..55c8b230 100644
--- a/kmod/src/file.c
+++ b/kmod/src/file.c
@@ -171,10 +171,8 @@ retry:
 		goto out;
 
 	if (scoutfs_per_task_add_excl(&si->pt_data_lock, &pt_ent, scoutfs_inode_lock)) {
-		ret = scoutfs_data_wait_check_iter(inode, iocb->ki_pos, to,
-						   SEF_OFFLINE,
-						   SCOUTFS_IOC_DWO_READ,
-						   &dw, scoutfs_inode_lock);
+		ret = scoutfs_data_wait_check(inode, iocb->ki_pos, iov_iter_count(to), SEF_OFFLINE,
+					      SCOUTFS_IOC_DWO_READ, &dw, scoutfs_inode_lock);
 		if (ret != 0)
 			goto out;
 	} else {
@@ -205,8 +203,7 @@ ssize_t scoutfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	struct scoutfs_lock *scoutfs_inode_lock = NULL;
 	SCOUTFS_DECLARE_PER_TASK_ENTRY(pt_ent);
 	DECLARE_DATA_WAIT(dw);
-	int ret;
-	int written;
+	ssize_t ret;
 
 retry:
 	inode_lock(inode);
@@ -225,17 +222,15 @@ retry:
 
 	if (scoutfs_per_task_add_excl(&si->pt_data_lock, &pt_ent, scoutfs_inode_lock)) {
 		/* data_version is per inode, whole file must be online */
-		ret = scoutfs_data_wait_check_iter(inode, iocb->ki_pos, from,
-						   SEF_OFFLINE,
-						   SCOUTFS_IOC_DWO_WRITE,
-						   &dw, scoutfs_inode_lock);
+		ret = scoutfs_data_wait_check(inode, 0, i_size_read(inode), SEF_OFFLINE,
+					      SCOUTFS_IOC_DWO_WRITE, &dw, scoutfs_inode_lock);
 		if (ret != 0)
 			goto out;
 	}
 
 	/* XXX: remove SUID bit */
 
-	written = __generic_file_write_iter(iocb, from);
+	ret = __generic_file_write_iter(iocb, from);
 
 out:
 	scoutfs_per_task_del(&si->pt_data_lock, &pt_ent);
@@ -248,10 +243,10 @@ out:
 			goto retry;
 	}
 
-	if (ret > 0 || ret == -EIOCBQUEUED)
-		ret = generic_write_sync(iocb, written);
+	if (ret > 0)
+		ret = generic_write_sync(iocb, ret);
 
-	return written ? written : ret;
+	return ret;
 }
 #endif
 
diff --git a/kmod/src/forest.h b/kmod/src/forest.h
index 30564a11..24753e89 100644
--- a/kmod/src/forest.h
+++ b/kmod/src/forest.h
@@ -4,6 +4,7 @@
 struct scoutfs_alloc;
 struct scoutfs_block_writer;
 struct scoutfs_block;
+struct scoutfs_lock;
 
 #include "btree.h"
 
diff --git a/kmod/src/inode.c b/kmod/src/inode.c
index 540004cc..db76f798 100644
--- a/kmod/src/inode.c
+++ b/kmod/src/inode.c
@@ -91,7 +91,7 @@ static void scoutfs_inode_ctor(void *obj)
 
 	init_rwsem(&si->extent_sem);
 	mutex_init(&si->item_mutex);
-	seqcount_init(&si->seqcount);
+	seqlock_init(&si->seqlock);
 	si->staging = false;
 	scoutfs_per_task_init(&si->pt_data_lock);
 	atomic64_set(&si->data_waitq.changed, 0);
@@ -566,11 +566,9 @@ static void set_trans_seq(struct inode *inode, u64 *seq)
 	struct scoutfs_sb_info *sbi = SCOUTFS_SB(sb);
 
 	if (*seq != sbi->trans_seq) {
-		preempt_disable();
-		write_seqcount_begin(&si->seqcount);
+		write_seqlock(&si->seqlock);
 		*seq = sbi->trans_seq;
-		write_seqcount_end(&si->seqcount);
-		preempt_enable();
+		write_sequnlock(&si->seqlock);
 	}
 }
 
@@ -592,22 +590,18 @@ void scoutfs_inode_inc_data_version(struct inode *inode)
 {
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
 
-	preempt_disable();
-	write_seqcount_begin(&si->seqcount);
+	write_seqlock(&si->seqlock);
 	si->data_version++;
-	write_seqcount_end(&si->seqcount);
-	preempt_enable();
+	write_sequnlock(&si->seqlock);
 }
 
 void scoutfs_inode_set_data_version(struct inode *inode, u64 data_version)
 {
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
 
-	preempt_disable();
-	write_seqcount_begin(&si->seqcount);
+	write_seqlock(&si->seqlock);
 	si->data_version = data_version;
-	write_seqcount_end(&si->seqcount);
-	preempt_enable();
+	write_sequnlock(&si->seqlock);
 }
 
 void scoutfs_inode_add_onoff(struct inode *inode, s64 on, s64 off)
@@ -616,8 +610,7 @@ void scoutfs_inode_add_onoff(struct inode *inode, s64 on, s64 off)
 
 	if (inode && (on || off)) {
 		si = SCOUTFS_I(inode);
-		preempt_disable();
-		write_seqcount_begin(&si->seqcount);
+		write_seqlock(&si->seqlock);
 
 		/* inode and extents out of sync, bad callers */
 		if (((s64)si->online_blocks + on < 0) ||
@@ -638,8 +631,7 @@ void scoutfs_inode_add_onoff(struct inode *inode, s64 on, s64 off)
 						    si->online_blocks,
 						    si->offline_blocks);
 
-		write_seqcount_end(&si->seqcount);
-		preempt_enable();
+		write_sequnlock(&si->seqlock);
 	}
 
 	/* any time offline extents decreased we try and wake waiters */
@@ -647,16 +639,16 @@ void scoutfs_inode_add_onoff(struct inode *inode, s64 on, s64 off)
 		scoutfs_data_wait_changed(inode);
 }
 
-static u64 read_seqcount_u64(struct inode *inode, u64 *val)
+static u64 read_seqlock_u64(struct inode *inode, u64 *val)
 {
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
-	unsigned int seq;
+	unsigned seq;
 	u64 v;
 
 	do {
-		seq = read_seqcount_begin(&si->seqcount);
+		seq = read_seqbegin(&si->seqlock);
 		v = *val;
-	} while (read_seqcount_retry(&si->seqcount, seq));
+	} while (read_seqretry(&si->seqlock, seq));
 
 	return v;
 }
@@ -665,33 +657,33 @@ u64 scoutfs_inode_meta_seq(struct inode *inode)
 {
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
 
-	return read_seqcount_u64(inode, &si->meta_seq);
+	return read_seqlock_u64(inode, &si->meta_seq);
 }
 
 u64 scoutfs_inode_data_seq(struct inode *inode)
 {
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
 
-	return read_seqcount_u64(inode, &si->data_seq);
+	return read_seqlock_u64(inode, &si->data_seq);
 }
 
 u64 scoutfs_inode_data_version(struct inode *inode)
 {
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
 
-	return read_seqcount_u64(inode, &si->data_version);
+	return read_seqlock_u64(inode, &si->data_version);
 }
 
 void scoutfs_inode_get_onoff(struct inode *inode, s64 *on, s64 *off)
 {
 	struct scoutfs_inode_info *si = SCOUTFS_I(inode);
-	unsigned int seq;
+	unsigned seq;
 
 	do {
-		seq = read_seqcount_begin(&si->seqcount);
+		seq = read_seqbegin(&si->seqlock);
 		*on = SCOUTFS_I(inode)->online_blocks;
 		*off = SCOUTFS_I(inode)->offline_blocks;
-	} while (read_seqcount_retry(&si->seqcount, seq));
+	} while (read_seqretry(&si->seqlock, seq));
 }
 
 static int scoutfs_iget_test(struct inode *inode, void *arg)
diff --git a/kmod/src/inode.h b/kmod/src/inode.h
index 607ac9f8..dd8e33f3 100644
--- a/kmod/src/inode.h
+++ b/kmod/src/inode.h
@@ -47,7 +47,7 @@ struct scoutfs_inode_info {
 	atomic64_t last_refreshed;
 
 	/* initialized once for slab object */
-	seqcount_t seqcount;
+	seqlock_t seqlock;
 	bool staging;			/* holder of i_mutex is staging */
 	struct scoutfs_per_task pt_data_lock;
 	struct scoutfs_data_waitq data_waitq;
diff --git a/kmod/src/item.c b/kmod/src/item.c
index 673797ef..a99202cf 100644
--- a/kmod/src/item.c
+++ b/kmod/src/item.c
@@ -24,6 +24,7 @@
 #include "item.h"
 #include "forest.h"
 #include "block.h"
+#include "msg.h"
 #include "trans.h"
 #include "counters.h"
 #include "scoutfs_trace.h"
@@ -1670,13 +1671,24 @@ out:
 	return ret;
 }
 
-static int lock_safe(struct scoutfs_lock *lock, struct scoutfs_key *key,
+static int lock_safe(struct super_block *sb, struct scoutfs_lock *lock, struct scoutfs_key *key,
 		     int mode)
 {
-	if (WARN_ON_ONCE(!scoutfs_lock_protected(lock, key, mode)))
+	bool prot = scoutfs_lock_protected(lock, key, mode);
+
+	if (!prot) {
+		static bool once = false;
+		if (!once) {
+			scoutfs_err(sb, "lock (start "SK_FMT" end "SK_FMT" mode 0x%x) does not protect operation (key "SK_FMT" mode 0x%x)",
+				    SK_ARG(&lock->start), SK_ARG(&lock->end), lock->mode,
+				    SK_ARG(key), mode);
+			dump_stack();
+			once = true;
+		}
 		return -EINVAL;
-	else
-		return 0;
+	}
+
+	return 0;
 }
 
 static int optional_lock_mode_match(struct scoutfs_lock *lock, int mode)
@@ -1718,7 +1730,7 @@ int scoutfs_item_lookup(struct super_block *sb, struct scoutfs_key *key,
 
 	scoutfs_inc_counter(sb, item_lookup);
 
-	if ((ret = lock_safe(lock, key, SCOUTFS_LOCK_READ)))
+	if ((ret = lock_safe(sb, lock, key, SCOUTFS_LOCK_READ)))
 		goto out;
 
 	ret = get_cached_page(sb, cinf, lock, key, false, false, 0, &pg);
@@ -1793,7 +1805,7 @@ int scoutfs_item_next(struct super_block *sb, struct scoutfs_key *key,
 		goto out;
 	}
 
-	if ((ret = lock_safe(lock, key, SCOUTFS_LOCK_READ)))
+	if ((ret = lock_safe(sb, lock, key, SCOUTFS_LOCK_READ)))
 		goto out;
 
 	pos = *key;
@@ -1874,7 +1886,7 @@ int scoutfs_item_dirty(struct super_block *sb, struct scoutfs_key *key,
 
 	scoutfs_inc_counter(sb, item_dirty);
 
-	if ((ret = lock_safe(lock, key, SCOUTFS_LOCK_WRITE)))
+	if ((ret = lock_safe(sb, lock, key, SCOUTFS_LOCK_WRITE)))
 		goto out;
 
 	ret = scoutfs_forest_set_bloom_bits(sb, lock);
@@ -1920,7 +1932,7 @@ static int item_create(struct super_block *sb, struct scoutfs_key *key,
 
 	scoutfs_inc_counter(sb, item_create);
 
-	if ((ret = lock_safe(lock, key, mode)) ||
+	if ((ret = lock_safe(sb, lock, key, mode)) ||
 	    (ret = optional_lock_mode_match(primary, SCOUTFS_LOCK_WRITE)))
 		goto out;
 
@@ -1963,7 +1975,7 @@ int scoutfs_item_create(struct super_block *sb, struct scoutfs_key *key,
 			void *val, int val_len, struct scoutfs_lock *lock)
 {
 	return item_create(sb, key, val, val_len, lock, NULL,
-			   SCOUTFS_LOCK_READ, false);
+			   SCOUTFS_LOCK_WRITE, false);
 }
 
 int scoutfs_item_create_force(struct super_block *sb, struct scoutfs_key *key,
@@ -1994,7 +2006,7 @@ int scoutfs_item_update(struct super_block *sb, struct scoutfs_key *key,
 
 	scoutfs_inc_counter(sb, item_update);
 
-	if ((ret = lock_safe(lock, key, SCOUTFS_LOCK_WRITE)))
+	if ((ret = lock_safe(sb, lock, key, SCOUTFS_LOCK_WRITE)))
 		goto out;
 
 	ret = scoutfs_forest_set_bloom_bits(sb, lock);
@@ -2062,7 +2074,7 @@ int scoutfs_item_delta(struct super_block *sb, struct scoutfs_key *key,
 
 	scoutfs_inc_counter(sb, item_delta);
 
-	if ((ret = lock_safe(lock, key, SCOUTFS_LOCK_WRITE_ONLY)))
+	if ((ret = lock_safe(sb, lock, key, SCOUTFS_LOCK_WRITE_ONLY)))
 		goto out;
 
 	ret = scoutfs_forest_set_bloom_bits(sb, lock);
@@ -2135,7 +2147,7 @@ static int item_delete(struct super_block *sb, struct scoutfs_key *key,
 
 	scoutfs_inc_counter(sb, item_delete);
 
-	if ((ret = lock_safe(lock, key, mode)) ||
+	if ((ret = lock_safe(sb, lock, key, mode)) ||
 	    (ret = optional_lock_mode_match(primary, SCOUTFS_LOCK_WRITE)))
 		goto out;
 
diff --git a/utils/src/change_format_version.c b/utils/src/change_format_version.c
index 071e6303..1e5e1507 100644
--- a/utils/src/change_format_version.c
+++ b/utils/src/change_format_version.c
@@ -119,6 +119,16 @@ static int do_change_fmt_vers(struct change_fmt_vers_args *args)
 		goto out;
 	}
 
+	if (le64_to_cpu(meta_super->fmt_vers) > args->fmt_vers ||
+	    le64_to_cpu(data_super->fmt_vers) > args->fmt_vers) {
+		ret = -EPERM;
+		printf("Downgrade of Meta Format Version: %llu and Data Format Version: %llu to Format Version: %llu is not allowed\n",
+		       le64_to_cpu(meta_super->fmt_vers),
+		       le64_to_cpu(data_super->fmt_vers),
+		       args->fmt_vers);
+		goto out;
+	}
+
 	if (le64_to_cpu(meta_super->fmt_vers) != args->fmt_vers) {
 		meta_super->fmt_vers = cpu_to_le64(args->fmt_vers);
 
diff --git a/utils/src/mkfs.c b/utils/src/mkfs.c
index f27a5674..211302aa 100644
--- a/utils/src/mkfs.c
+++ b/utils/src/mkfs.c
@@ -274,6 +274,8 @@ static int do_mkfs(struct mkfs_args *args)
 	inode.ctime.nsec = inode.atime.nsec;
 	inode.mtime.sec = inode.atime.sec;
 	inode.mtime.nsec = inode.atime.nsec;
+	inode.crtime.sec = inode.atime.sec;
+	inode.crtime.nsec = inode.atime.nsec;
 	btree_append_item(bt, &key, &inode, sizeof(inode));
 
 	ret = write_block(meta_fd, SCOUTFS_BLOCK_MAGIC_BTREE, fsid, 1, blkno,