erofs: simplify compression configuration parser

Move erofs_load_compr_cfgs() into decompressor.c as well as introduce
a callback instead of a hard-coded switch for each algorithm for
simplicity.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20231022130957.11398-1-xiang@kernel.org

1 files changed, 8 insertions, 64 deletions

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 3700af9ee173..cc44fb2e001e 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -156,68 +156,15 @@ void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,
 	return buffer;
 }
 
-#ifdef CONFIG_EROFS_FS_ZIP
-static int erofs_load_compr_cfgs(struct super_block *sb,
-				 struct erofs_super_block *dsb)
+#ifndef CONFIG_EROFS_FS_ZIP
+static int z_erofs_parse_cfgs(struct super_block *sb,
+			      struct erofs_super_block *dsb)
 {
-	struct erofs_sb_info *sbi = EROFS_SB(sb);
-	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
-	unsigned int algs, alg;
-	erofs_off_t offset;
-	int size, ret = 0;
-
-	sbi->available_compr_algs = le16_to_cpu(dsb->u1.available_compr_algs);
-	if (sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS) {
-		erofs_err(sb, "try to load compressed fs with unsupported algorithms %x",
-			  sbi->available_compr_algs & ~Z_EROFS_ALL_COMPR_ALGS);
-		return -EINVAL;
-	}
-
-	erofs_init_metabuf(&buf, sb);
-	offset = EROFS_SUPER_OFFSET + sbi->sb_size;
-	alg = 0;
-	for (algs = sbi->available_compr_algs; algs; algs >>= 1, ++alg) {
-		void *data;
-
-		if (!(algs & 1))
-			continue;
-
-		data = erofs_read_metadata(sb, &buf, &offset, &size);
-		if (IS_ERR(data)) {
-			ret = PTR_ERR(data);
-			break;
-		}
+	if (!dsb->u1.available_compr_algs)
+		return 0;
 
-		switch (alg) {
-		case Z_EROFS_COMPRESSION_LZ4:
-			ret = z_erofs_load_lz4_config(sb, dsb, data, size);
-			break;
-		case Z_EROFS_COMPRESSION_LZMA:
-			ret = z_erofs_load_lzma_config(sb, dsb, data, size);
-			break;
-		case Z_EROFS_COMPRESSION_DEFLATE:
-			ret = z_erofs_load_deflate_config(sb, dsb, data, size);
-			break;
-		default:
-			DBG_BUGON(1);
-			ret = -EFAULT;
-		}
-		kfree(data);
-		if (ret)
-			break;
-	}
-	erofs_put_metabuf(&buf);
-	return ret;
-}
-#else
-static int erofs_load_compr_cfgs(struct super_block *sb,
-				 struct erofs_super_block *dsb)
-{
-	if (dsb->u1.available_compr_algs) {
-		erofs_err(sb, "try to load compressed fs when compression is disabled");
-		return -EINVAL;
-	}
-	return 0;
+	erofs_err(sb, "compression disabled, unable to mount compressed EROFS");
+	return -EOPNOTSUPP;
 }
 #endif
 
@@ -406,10 +353,7 @@ static int erofs_read_superblock(struct super_block *sb)
 	}
 
 	/* parse on-disk compression configurations */
-	if (erofs_sb_has_compr_cfgs(sbi))
-		ret = erofs_load_compr_cfgs(sb, dsb);
-	else
-		ret = z_erofs_load_lz4_config(sb, dsb, NULL, 0);
+	ret = z_erofs_parse_cfgs(sb, dsb);
 	if (ret < 0)
 		goto out;