[PATCH 6.9.y] erofs: avoid allocating DEFLATE streams before mounting

Gao Xiang
2024-05-30T09:22:14Z

index 81e65c453ef0..3a3461561a3c 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,