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-rw-r--r--lib/compress.c211
1 files changed, 205 insertions, 6 deletions
diff --git a/lib/compress.c b/lib/compress.c
index edff7ab..ed4dba4 100644
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -20,6 +20,8 @@
static struct erofs_compress compresshandle;
static int compressionlevel;
+static struct z_erofs_map_header mapheader;
+
struct z_erofs_vle_compress_ctx {
u8 *metacur;
@@ -33,7 +35,7 @@ struct z_erofs_vle_compress_ctx {
#define Z_EROFS_LEGACY_MAP_HEADER_SIZE \
(sizeof(struct z_erofs_map_header) + Z_EROFS_VLE_LEGACY_HEADER_PADDING)
-static unsigned int get_vle_compress_metasize(erofs_off_t filesize)
+static unsigned int vle_compressmeta_capacity(erofs_off_t filesize)
{
const unsigned int indexsize = BLK_ROUND_UP(filesize) *
sizeof(struct z_erofs_vle_decompressed_index);
@@ -193,17 +195,186 @@ nocompression:
return 0;
}
+struct z_erofs_compressindex_vec {
+ union {
+ erofs_blk_t blkaddr;
+ u16 delta[2];
+ } u;
+ u16 clusterofs;
+ u8 clustertype;
+};
+
+static void *parse_legacy_indexes(struct z_erofs_compressindex_vec *cv,
+ unsigned int nr, void *metacur)
+{
+ struct z_erofs_vle_decompressed_index *const db = metacur;
+ unsigned int i;
+
+ for (i = 0; i < nr; ++i, ++cv) {
+ struct z_erofs_vle_decompressed_index *const di = db + i;
+ const unsigned int advise = le16_to_cpu(di->di_advise);
+
+ cv->clustertype = (advise >> Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT) &
+ ((1 << Z_EROFS_VLE_DI_CLUSTER_TYPE_BITS) - 1);
+ cv->clusterofs = le16_to_cpu(di->di_clusterofs);
+
+ if (cv->clustertype == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
+ cv->u.delta[0] = le16_to_cpu(di->di_u.delta[0]);
+ cv->u.delta[1] = le16_to_cpu(di->di_u.delta[1]);
+ } else {
+ cv->u.blkaddr = le32_to_cpu(di->di_u.blkaddr);
+ }
+ }
+ return db + nr;
+}
+
+static void *write_compacted_indexes(u8 *out,
+ struct z_erofs_compressindex_vec *cv,
+ erofs_blk_t *blkaddr_ret,
+ unsigned int destsize,
+ unsigned int logical_clusterbits,
+ bool final)
+{
+ unsigned int vcnt, encodebits, pos, i;
+ erofs_blk_t blkaddr;
+
+ if (destsize == 4) {
+ vcnt = 2;
+ } else if (destsize == 2 && logical_clusterbits == 12) {
+ vcnt = 16;
+ } else {
+ return ERR_PTR(-EINVAL);
+ }
+ encodebits = (vcnt * destsize * 8 - 32) / vcnt;
+ blkaddr = *blkaddr_ret;
+
+ pos = 0;
+ for (i = 0; i < vcnt; ++i) {
+ unsigned int offset, v;
+ u8 ch, rem;
+
+ if (cv[i].clustertype == Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD) {
+ if (i + 1 == vcnt)
+ offset = cv[i].u.delta[1];
+ else
+ offset = cv[i].u.delta[0];
+ } else {
+ offset = cv[i].clusterofs;
+ ++blkaddr;
+ if (cv[i].u.blkaddr != blkaddr) {
+ if (i + 1 != vcnt)
+ DBG_BUGON(!final);
+ DBG_BUGON(cv[i].u.blkaddr);
+ }
+ }
+ v = (cv[i].clustertype << logical_clusterbits) | offset;
+ rem = pos & 7;
+ ch = out[pos / 8] & ((1 << rem) - 1);
+ out[pos / 8] = (v << rem) | ch;
+ out[pos / 8 + 1] = v >> (8 - rem);
+ out[pos / 8 + 2] = v >> (16 - rem);
+ pos += encodebits;
+ }
+ DBG_BUGON(destsize * vcnt * 8 != pos + 32);
+ *(__le32 *)(out + destsize * vcnt - 4) = cpu_to_le32(*blkaddr_ret);
+ *blkaddr_ret = blkaddr;
+ return out + destsize * vcnt;
+}
+
+int z_erofs_convert_to_compacted_format(struct erofs_inode *inode,
+ erofs_blk_t blkaddr,
+ unsigned int legacymetasize,
+ unsigned int logical_clusterbits)
+{
+ const uint headerpos = Z_EROFS_VLE_EXTENT_ALIGN(inode->inode_isize +
+ inode->xattr_isize) +
+ sizeof(struct z_erofs_map_header);
+ const uint totalidx = (legacymetasize -
+ Z_EROFS_LEGACY_MAP_HEADER_SIZE) / 8;
+ u8 *out, *in;
+ struct z_erofs_compressindex_vec cv[16];
+ /* # of 8-byte units so that it can be aligned with 32 bytes */
+ unsigned int compacted_4b_initial, compacted_4b_end;
+ unsigned int compacted_2b;
+
+ if (logical_clusterbits < LOG_BLOCK_SIZE || LOG_BLOCK_SIZE < 12)
+ return -EINVAL;
+ if (logical_clusterbits > 14) /* currently not supported */
+ return -ENOTSUP;
+ if (logical_clusterbits == 12) {
+ compacted_4b_initial = (32 - headerpos % 32) / 4;
+ if (compacted_4b_initial == 32 / 4)
+ compacted_4b_initial = 0;
+
+ if (compacted_4b_initial > totalidx) {
+ compacted_4b_initial = compacted_2b = 0;
+ compacted_4b_end = totalidx;
+ } else {
+ compacted_2b = rounddown(totalidx -
+ compacted_4b_initial, 16);
+ compacted_4b_end = totalidx - compacted_4b_initial -
+ compacted_2b;
+ }
+ } else {
+ compacted_2b = compacted_4b_initial = 0;
+ compacted_4b_end = totalidx;
+ }
+
+ out = in = inode->compressmeta;
+
+ /* write out compacted header */
+ memcpy(out, &mapheader, sizeof(mapheader));
+ out += sizeof(mapheader);
+ in += Z_EROFS_LEGACY_MAP_HEADER_SIZE;
+
+ /* generate compacted_4b_initial */
+ while (compacted_4b_initial) {
+ in = parse_legacy_indexes(cv, 2, in);
+ out = write_compacted_indexes(out, cv, &blkaddr,
+ 4, logical_clusterbits, false);
+ compacted_4b_initial -= 2;
+ }
+ DBG_BUGON(compacted_4b_initial);
+
+ /* generate compacted_2b */
+ while (compacted_2b) {
+ in = parse_legacy_indexes(cv, 16, in);
+ out = write_compacted_indexes(out, cv, &blkaddr,
+ 2, logical_clusterbits, false);
+ compacted_2b -= 16;
+ }
+ DBG_BUGON(compacted_2b);
+
+ /* generate compacted_4b_end */
+ while (compacted_4b_end > 1) {
+ in = parse_legacy_indexes(cv, 2, in);
+ out = write_compacted_indexes(out, cv, &blkaddr,
+ 4, logical_clusterbits, false);
+ compacted_4b_end -= 2;
+ }
+
+ /* generate final compacted_4b_end if needed */
+ if (compacted_4b_end) {
+ memset(cv, 0, sizeof(cv));
+ in = parse_legacy_indexes(cv, 1, in);
+ out = write_compacted_indexes(out, cv, &blkaddr,
+ 4, logical_clusterbits, true);
+ }
+ inode->extent_isize = out - (u8 *)inode->compressmeta;
+ inode->data_mapping_mode = EROFS_INODE_FLAT_COMPRESSION;
+ return 0;
+}
+
int erofs_write_compressed_file(struct erofs_inode *inode)
{
- const unsigned int metasize = get_vle_compress_metasize(inode->i_size);
struct erofs_buffer_head *bh;
struct z_erofs_vle_compress_ctx ctx;
erofs_off_t remaining;
erofs_blk_t blkaddr, compressed_blocks;
-
+ unsigned int legacymetasize;
int ret, fd;
- u8 *compressmeta = malloc(metasize);
+ u8 *compressmeta = malloc(vle_compressmeta_capacity(inode->i_size));
if (!compressmeta)
return -ENOMEM;
@@ -276,8 +447,16 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
inode->compressmeta = compressmeta;
inode->idata_size = 0;
inode->u.i_blocks = compressed_blocks;
- inode->extent_isize = metasize;
- inode->data_mapping_mode = EROFS_INODE_LAYOUT_COMPRESSION;
+
+ legacymetasize = ctx.metacur - compressmeta;
+ if (cfg.c_legacy_compress) {
+ inode->extent_isize = legacymetasize;
+ inode->data_mapping_mode = EROFS_INODE_FLAT_COMPRESSION_LEGACY;
+ } else {
+ ret = z_erofs_convert_to_compacted_format(inode, blkaddr - 1,
+ legacymetasize, 12);
+ DBG_BUGON(ret);
+ }
return 0;
err_bdrop:
@@ -289,8 +468,16 @@ err_free:
return ret;
}
+static int erofs_get_compress_algorithm_id(const char *name)
+{
+ if (!strcmp(name, "lz4") || !strcmp(name, "lz4hc"))
+ return Z_EROFS_COMPRESSION_LZ4;
+ return -ENOTSUP;
+}
+
int z_erofs_compress_init(void)
{
+ unsigned int algorithmtype[2];
/* initialize for primary compression algorithm */
int ret = erofs_compressor_init(&compresshandle,
cfg.c_compr_alg_master);
@@ -300,6 +487,18 @@ int z_erofs_compress_init(void)
compressionlevel = cfg.c_compr_level_master < 0 ?
compresshandle.alg->default_level :
cfg.c_compr_level_master;
+
+ /* figure out mapheader */
+ ret = erofs_get_compress_algorithm_id(cfg.c_compr_alg_master);
+ if (ret < 0)
+ return ret;
+
+ algorithmtype[0] = ret; /* primary algorithm (head 0) */
+ algorithmtype[1] = 0; /* secondary algorithm (head 1) */
+ mapheader.h_advise |= Z_EROFS_ADVISE_COMPACTED_2B;
+ mapheader.h_algorithmtype = algorithmtype[1] << 4 |
+ algorithmtype[0];
+ mapheader.h_clusterbits = LOG_BLOCK_SIZE - 12;
return 0;
}