1 files changed, 29 insertions, 26 deletions

diff --git a/fs/erofs/decompressor_deflate.c b/fs/erofs/decompressor_deflate.c
index 81e65c453e..3a3461561a 100644
--- a/fs/erofs/decompressor_deflate.c
+++ b/fs/erofs/decompressor_deflate.c
@@ -46,39 +46,15 @@ int __init z_erofs_deflate_init(void)
 	/* by default, use # of possible CPUs instead */
 	if (!z_erofs_deflate_nstrms)
 		z_erofs_deflate_nstrms = num_possible_cpus();
-
-	for (; z_erofs_deflate_avail_strms < z_erofs_deflate_nstrms;
-	     ++z_erofs_deflate_avail_strms) {
-		struct z_erofs_deflate *strm;
-
-		strm = kzalloc(sizeof(*strm), GFP_KERNEL);
-		if (!strm)
-			goto out_failed;
-
-		/* XXX: in-kernel zlib cannot shrink windowbits currently */
-		strm->z.workspace = vmalloc(zlib_inflate_workspacesize());
-		if (!strm->z.workspace) {
-			kfree(strm);
-			goto out_failed;
-		}
-
-		spin_lock(&z_erofs_deflate_lock);
-		strm->next = z_erofs_deflate_head;
-		z_erofs_deflate_head = strm;
-		spin_unlock(&z_erofs_deflate_lock);
-	}
 	return 0;
-
-out_failed:
-	erofs_err(NULL, "failed to allocate zlib workspace");
-	z_erofs_deflate_exit();
-	return -ENOMEM;
 }
 
 int z_erofs_load_deflate_config(struct super_block *sb,
 			struct erofs_super_block *dsb, void *data, int size)
 {
 	struct z_erofs_deflate_cfgs *dfl = data;
+	static DEFINE_MUTEX(deflate_resize_mutex);
+	static bool inited;
 
 	if (!dfl || size < sizeof(struct z_erofs_deflate_cfgs)) {
 		erofs_err(sb, "invalid deflate cfgs, size=%u", size);
@@ -89,9 +65,36 @@ int z_erofs_load_deflate_config(struct super_block *sb,
 		erofs_err(sb, "unsupported windowbits %u", dfl->windowbits);
 		return -EOPNOTSUPP;
 	}
+	mutex_lock(&deflate_resize_mutex);
+	if (!inited) {
+		for (; z_erofs_deflate_avail_strms < z_erofs_deflate_nstrms;
+		     ++z_erofs_deflate_avail_strms) {
+			struct z_erofs_deflate *strm;
+
+			strm = kzalloc(sizeof(*strm), GFP_KERNEL);
+			if (!strm)
+				goto failed;
+			/* XXX: in-kernel zlib cannot customize windowbits */
+			strm->z.workspace = vmalloc(zlib_inflate_workspacesize());
+			if (!strm->z.workspace) {
+				kfree(strm);
+				goto failed;
+			}
 
+			spin_lock(&z_erofs_deflate_lock);
+			strm->next = z_erofs_deflate_head;
+			z_erofs_deflate_head = strm;
+			spin_unlock(&z_erofs_deflate_lock);
+		}
+		inited = true;
+	}
+	mutex_unlock(&deflate_resize_mutex);
 	erofs_info(sb, "EXPERIMENTAL DEFLATE feature in use. Use at your own risk!");
 	return 0;
+failed:
+	mutex_unlock(&deflate_resize_mutex);
+	z_erofs_deflate_exit();
+	return -ENOMEM;
 }
 
 int z_erofs_deflate_decompress(struct z_erofs_decompress_req *rq,