update

2026-08-14 12:01:38 +02:00
commit 0bbc249155
21 changed files with 6786 additions and 0 deletions
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2019 HUAWEI, Inc.
+ *             https://www.huawei.com/
+ * Copyright (C) 2024 Alibaba Cloud
+ */
+
+#include <sys/param.h>
+#include <sys/endian.h>
+#include <sys/libkern.h>
+#include <sys/malloc.h>
+#include <sys/systm.h>
+
+#include "internal.h"
+
+static int
+z_erofs_load_lz4_config(struct erofs_mount *em,
+    const struct erofs_super_block *dsb, const void *data, size_t size)
+{
+	const struct z_erofs_lz4_cfgs *lz4;
+	uint32_t max_pclusterblks;
+	uint16_t distance;
+
+	if (data != NULL) {
+		if (size < sizeof(*lz4))
+			return (EINVAL);
+		lz4 = data;
+		distance = le16toh(lz4->max_distance);
+		max_pclusterblks = le16toh(lz4->max_pclusterblks);
+		if (max_pclusterblks == 0)
+			max_pclusterblks = 1;
+		else if (max_pclusterblks >
+		    (Z_EROFS_PCLUSTER_MAX_SIZE >> em->block_bits))
+			return (EINVAL);
+	} else {
+		distance = le16toh(dsb->u1.lz4_max_distance);
+		if (distance == 0 && !erofs_sb_has_lz4_0padding(em))
+			return (0);
+		max_pclusterblks = 1;
+		em->available_compr_algs = 1U << Z_EROFS_COMPRESSION_LZ4;
+	}
+	em->lz4.max_pclusterblks = max_pclusterblks;
+	em->lz4.max_distance_pages = distance != 0 ?
+	    howmany(distance, PAGE_SIZE) + 1 :
+	    howmany(UINT16_MAX, PAGE_SIZE) + 1;
+	return (0);
+}
+
+static int
+z_erofs_read_cfg(struct erofs_mount *em, uint64_t *offset, void **bufp,
+    size_t *sizep)
+{
+	uint8_t length_buf[2];
+	uint64_t aligned;
+	uint16_t length;
+	void *buf;
+	int error;
+
+	aligned = roundup2(*offset, 4);
+	if (aligned > UINT64_MAX - sizeof(length_buf))
+		return (EOVERFLOW);
+	error = erofs_bread(em, aligned, sizeof(length_buf), &buf);
+	if (error != 0)
+		return (error);
+	memcpy(length_buf, buf, sizeof(length_buf));
+	erofs_brelse(buf);
+	length = le16dec(length_buf);
+	*sizep = length != 0 ? length : UINT16_MAX + 1U;
+	if (*sizep > 65536 || aligned + sizeof(length_buf) >
+	    UINT64_MAX - *sizep)
+		return (EOVERFLOW);
+	*offset = aligned + sizeof(length_buf);
+	error = erofs_bread(em, *offset, *sizep, bufp);
+	if (error == 0)
+		*offset += *sizep;
+	return (error);
+}
+
+int
+z_erofs_parse_cfgs(struct erofs_mount *em,
+    const struct erofs_super_block *dsb)
+{
+	uint64_t offset;
+	uint16_t algorithms;
+	void *data;
+	size_t size;
+	int algorithm, error;
+
+	if (!erofs_sb_has_compr_cfgs(em))
+		return (z_erofs_load_lz4_config(em, dsb, NULL, 0));
+	algorithms = le16toh(dsb->u1.available_compr_algs);
+	em->available_compr_algs = algorithms;
+	if ((algorithms & ~Z_EROFS_ALL_COMPR_ALGS) != 0)
+		return (EOPNOTSUPP);
+	offset = EROFS_SUPER_OFFSET + em->sb_size;
+	for (algorithm = 0; algorithm < Z_EROFS_COMPRESSION_MAX;
+	    ++algorithm) {
+		if ((algorithms & (1U << algorithm)) == 0)
+			continue;
+		error = z_erofs_read_cfg(em, &offset, &data, &size);
+		if (error != 0)
+			return (error);
+		switch (algorithm) {
+		case Z_EROFS_COMPRESSION_LZ4:
+			error = z_erofs_load_lz4_config(em, dsb, data, size);
+			break;
+		case Z_EROFS_COMPRESSION_LZMA:
+			error = z_erofs_load_lzma_config(em, data, size);
+			break;
+		case Z_EROFS_COMPRESSION_DEFLATE:
+			error = z_erofs_load_deflate_config(em, data, size);
+			break;
+		case Z_EROFS_COMPRESSION_ZSTD:
+			error = z_erofs_load_zstd_config(em, data, size);
+			break;
+		default:
+			error = EOPNOTSUPP;
+			break;
+		}
+		erofs_brelse(data);
+		if (error != 0)
+			return (error);
+	}
+	return (0);
+}
+
+static int
+z_erofs_transform_plain(struct erofs_mount *em,
+    const struct erofs_map_blocks *map, const uint8_t *src, size_t srclen,
+    uint8_t *dst, size_t dstlen)
+{
+	size_t first, offset;
+
+	if (dstlen > srclen)
+		return (EINTEGRITY);
+	if (map->m_algorithmformat == Z_EROFS_COMPRESSION_SHIFTED) {
+		memmove(dst, src, dstlen);
+		return (0);
+	}
+	first = MIN((size_t)(em->block_size -
+	    (map->m_la & (em->block_size - 1))), dstlen);
+	offset = (srclen - first) & (em->block_size - 1);
+	if (offset > srclen || first > srclen - offset)
+		return (EINTEGRITY);
+	memmove(dst, src + offset, first);
+	if (first < dstlen)
+		memmove(dst + first, src, dstlen - first);
+	return (0);
+}
+
+int
+z_erofs_decompress(struct erofs_mount *em,
+    const struct erofs_map_blocks *map, const void *src0, size_t srclen,
+    void *dst, size_t dstlen, bool partial)
+{
+	const uint8_t *src;
+	size_t padding, padding_limit;
+	int ret;
+
+	if (map->m_algorithmformat == Z_EROFS_COMPRESSION_SHIFTED ||
+	    map->m_algorithmformat == Z_EROFS_COMPRESSION_INTERLACED)
+		return (z_erofs_transform_plain(em, map, src0, srclen, dst,
+		    dstlen));
+	if ((unsigned char)map->m_algorithmformat >= Z_EROFS_COMPRESSION_MAX)
+		return (EOPNOTSUPP);
+
+	src = src0;
+	if (map->m_algorithmformat != Z_EROFS_COMPRESSION_LZ4 ||
+	    erofs_sb_has_lz4_0padding(em)) {
+		padding_limit = MIN(srclen, em->block_size -
+		    (map->m_pa & (em->block_size - 1)));
+		for (padding = 0; padding < padding_limit && src[padding] == 0;
+		    ++padding)
+			;
+		if (padding == padding_limit)
+			return (EINTEGRITY);
+		src += padding;
+		srclen -= padding;
+	}
+
+	switch (map->m_algorithmformat) {
+	case Z_EROFS_COMPRESSION_LZ4:
+		ret = lz4_decompress(__DECONST(void *, src), dst, srclen,
+		    dstlen, partial);
+		break;
+	case Z_EROFS_COMPRESSION_LZMA:
+		if (em->lzma_dict_size == 0)
+			return (EINTEGRITY);
+		ret = lzma_decompress(src, srclen, dst, dstlen,
+		    em->lzma_dict_size, partial);
+		break;
+	case Z_EROFS_COMPRESSION_DEFLATE:
+		ret = deflate_decompress(__DECONST(void *, src), srclen, dst,
+		    dstlen, em->deflate_windowbits, partial);
+		break;
+	case Z_EROFS_COMPRESSION_ZSTD:
+		ret = zstd_decompress(__DECONST(void *, src), srclen, dst,
+		    dstlen, em->zstd_windowlog + 10, partial);
+		break;
+	default:
+		return (EOPNOTSUPP);
+	}
+	return (ret == 0 ? 0 : EIO);
+}