diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index e16545849ea7..c08c0f578bc6 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -376,7 +376,7 @@ static ssize_t erofs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 		if (bdev)
 			blksize_mask = bdev_logical_block_size(bdev) - 1;
 		else
-			blksize_mask = (1 << inode->i_blkbits) - 1;
+			blksize_mask = i_blocksize(inode) - 1;
 
 		if ((iocb->ki_pos | iov_iter_count(to) |
 		     iov_iter_alignment(to)) & blksize_mask)
diff --git a/fs/erofs/decompressor_lzma.c b/fs/erofs/decompressor_lzma.c
index 091fd5adf818..d38e19c11270 100644
--- a/fs/erofs/decompressor_lzma.c
+++ b/fs/erofs/decompressor_lzma.c
@@ -47,7 +47,7 @@ void z_erofs_lzma_exit(void)
 	}
 }
 
-int z_erofs_lzma_init(void)
+int __init z_erofs_lzma_init(void)
 {
 	unsigned int i;
 
@@ -278,7 +278,7 @@ again:
 		}
 	}
 	if (no < nrpages_out && strm->buf.out)
-		kunmap(rq->in[no]);
+		kunmap(rq->out[no]);
 	if (ni < nrpages_in)
 		kunmap(rq->in[ni]);
 	/* 4. push back LZMA stream context to the global list */
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index 3f3561d37d1b..1db018f8c2e8 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -486,7 +486,7 @@ static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
 void *erofs_get_pcpubuf(unsigned int requiredpages);
 void erofs_put_pcpubuf(void *ptr);
 int erofs_pcpubuf_growsize(unsigned int nrpages);
-void erofs_pcpubuf_init(void);
+void __init erofs_pcpubuf_init(void);
 void erofs_pcpubuf_exit(void);
 
 int erofs_register_sysfs(struct super_block *sb);
@@ -545,7 +545,7 @@ static inline int z_erofs_fill_inode(struct inode *inode) { return -EOPNOTSUPP;
 #endif	/* !CONFIG_EROFS_FS_ZIP */
 
 #ifdef CONFIG_EROFS_FS_ZIP_LZMA
-int z_erofs_lzma_init(void);
+int __init z_erofs_lzma_init(void);
 void z_erofs_lzma_exit(void);
 int z_erofs_load_lzma_config(struct super_block *sb,
 			     struct erofs_super_block *dsb,
diff --git a/fs/erofs/pcpubuf.c b/fs/erofs/pcpubuf.c
index a2efd833d1b6..c7a4b1d77069 100644
--- a/fs/erofs/pcpubuf.c
+++ b/fs/erofs/pcpubuf.c
@@ -114,7 +114,7 @@ out:
 	return ret;
 }
 
-void erofs_pcpubuf_init(void)
+void __init erofs_pcpubuf_init(void)
 {
 	int cpu;
 
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 3247d2422bea..f1708c77a991 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1312,12 +1312,12 @@ static int z_erofs_decompress_pcluster(struct z_erofs_decompress_backend *be,
 
 	if (!be->decompressed_pages)
 		be->decompressed_pages =
-			kcalloc(be->nr_pages, sizeof(struct page *),
-				GFP_KERNEL | __GFP_NOFAIL);
+			kvcalloc(be->nr_pages, sizeof(struct page *),
+				 GFP_KERNEL | __GFP_NOFAIL);
 	if (!be->compressed_pages)
 		be->compressed_pages =
-			kcalloc(pclusterpages, sizeof(struct page *),
-				GFP_KERNEL | __GFP_NOFAIL);
+			kvcalloc(pclusterpages, sizeof(struct page *),
+				 GFP_KERNEL | __GFP_NOFAIL);
 
 	z_erofs_parse_out_bvecs(be);
 	err2 = z_erofs_parse_in_bvecs(be, &overlapped);
@@ -1365,7 +1365,7 @@ out:
 	}
 	if (be->compressed_pages < be->onstack_pages ||
 	    be->compressed_pages >= be->onstack_pages + Z_EROFS_ONSTACK_PAGES)
-		kfree(be->compressed_pages);
+		kvfree(be->compressed_pages);
 	z_erofs_fill_other_copies(be, err);
 
 	for (i = 0; i < be->nr_pages; ++i) {
@@ -1384,7 +1384,7 @@ out:
 	}
 
 	if (be->decompressed_pages != be->onstack_pages)
-		kfree(be->decompressed_pages);
+		kvfree(be->decompressed_pages);
 
 	pcl->length = 0;
 	pcl->partial = true;
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 8bf6d30518b6..655da4d739cb 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -757,9 +757,6 @@ int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map,
 	err = z_erofs_do_map_blocks(inode, map, flags);
 out:
 	trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err);
-
-	/* aggressively BUG_ON iff CONFIG_EROFS_FS_DEBUG is on */
-	DBG_BUGON(err < 0 && err != -ENOMEM);
 	return err;
 }