diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index f09c152d5516..d35d17787530 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -306,4 +306,9 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 	if (!(map.m_flags & EROFS_MAP_MAPPED)) {
 		iomap->type = IOMAP_HOLE;
+		pr_info("IOMAPDBG e_begin: ino=%llu la=%llu llen=%llu mflags=0x%x -> HOLE addr=%llx devid=%u\n",
+			(unsigned long long)inode->i_ino,
+			(unsigned long long)map.m_la, (unsigned long long)map.m_llen,
+			(unsigned int)map.m_flags, (unsigned long long)iomap->addr,
+			(unsigned int)map.m_deviceid);
 		return 0;
 	}
@@ -346,4 +351,10 @@ static int erofs_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
 		iomap->type = IOMAP_MAPPED;
 	}
+	pr_info("IOMAPDBG e_begin: ino=%llu la=%llu llen=%llu mflags=0x%x pa=%llx -> type=%u addr=%llx bdev=%d devid=%u\n",
+		(unsigned long long)inode->i_ino, (unsigned long long)map.m_la,
+		(unsigned long long)map.m_llen, (unsigned int)map.m_flags,
+		(unsigned long long)map.m_pa, (unsigned int)iomap->type,
+		(unsigned long long)iomap->addr, !!iomap->bdev,
+		(unsigned int)map.m_deviceid);
 	return 0;
 }
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 678f4c5329e7..fd8ec852c6e6 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -538,4 +538,8 @@ static void iomap_read_end(struct folio *folio, size_t bytes_submitted)
 		if (end_read)
 			uptodate = ifs_is_fully_uptodate(folio, ifs);
+		pr_info("IOMAPDBG read_end: ino=%llu fpos=%lld fsize=%zu submitted=%zu pending=%u end_read=%d\n",
+			(unsigned long long)folio->mapping->host->i_ino,
+			folio_pos(folio), folio_size(folio), bytes_submitted,
+			ifs->read_bytes_pending, end_read);
 		spin_unlock_irq(&ifs->state_lock);
 		if (end_read)
@@ -551,4 +555,7 @@ static void iomap_read_end(struct folio *folio, size_t bytes_submitted)
 		 */
 		WARN_ON_ONCE(bytes_submitted);
+		pr_info("IOMAPDBG read_end_noifs: ino=%llu fpos=%lld fsize=%zu submitted=%zu\n",
+			(unsigned long long)folio->mapping->host->i_ino,
+			folio_pos(folio), folio_size(folio), bytes_submitted);
 		folio_unlock(folio);
 	}
@@ -582,4 +589,9 @@ static int iomap_read_folio_iter(struct iomap_iter *iter,
 				&plen);
 
+		pr_info("IOMAPDBG rf_iter: ino=%llu fpos=%lld fsize=%zu pos=%lld type=%u poff=%zu plen=%zu submitted=%zu\n",
+			(unsigned long long)iter->inode->i_ino, folio_pos(folio),
+			folio_size(folio), pos, (unsigned int)iomap->type,
+			poff, plen, *bytes_submitted);
+
 		pos_diff = pos - iter->pos;
 		if (WARN_ON_ONCE(pos_diff + plen > length))
@@ -640,4 +652,8 @@ static int iomap_read_folio_iter(struct iomap_iter *iter,
 		}
 
+		pr_info("IOMAPDBG rf_done: ino=%llu fpos=%lld type=%u poff=%zu plen=%zu submitted=%zu\n",
+			(unsigned long long)iter->inode->i_ino, folio_pos(folio),
+			(unsigned int)iomap->type, poff, plen, *bytes_submitted);
+
 		ret = iomap_iter_advance(iter, plen);
 		if (ret)
diff --git a/fs/iomap/iter.c b/fs/iomap/iter.c
index fd8791c4963b..3f6d6966c31e 100644
--- a/fs/iomap/iter.c
+++ b/fs/iomap/iter.c
@@ -127,8 +127,24 @@ int iomap_iter(struct iomap_iter *iter, const struct iomap_ops *ops)
 
 	iter->status = 0;
-	if (ret > 0)
+	if (ret > 0) {
 		iomap_iter_done(iter);
-	else if (ret < 0)
-		iomap_iter_clean_fbatch(iter, &iter->iomap);
+		pr_info("IOMAPDBG iter_enter: ino=%llu pos=%lld len=%llu start=%lld | iomap off=%lld len=%llu type=%u addr=%llx flags=0x%x src=%u\n",
+			(unsigned long long)iter->inode->i_ino, iter->pos,
+			(unsigned long long)iter->len, iter->iter_start_pos,
+			iter->iomap.offset, (unsigned long long)iter->iomap.length,
+			(unsigned int)iter->iomap.type,
+			(unsigned long long)iter->iomap.addr,
+			(unsigned int)iter->iomap.flags,
+			(unsigned int)iter->srcmap.type);
+	} else {
+		if (ret < 0)
+			iomap_iter_clean_fbatch(iter, &iter->iomap);
+		pr_info("IOMAPDBG iter_exit: ino=%llu ret=%d pos=%lld len=%llu start=%lld | iomap off=%lld len=%llu type=%u addr=%llx\n",
+			(unsigned long long)iter->inode->i_ino, ret, iter->pos,
+			(unsigned long long)iter->len, iter->iter_start_pos,
+			iter->iomap.offset, (unsigned long long)iter->iomap.length,
+			(unsigned int)iter->iomap.type,
+			(unsigned long long)iter->iomap.addr);
+	}
 
 	return ret;