erofs-utils: introduce ondisk compression cfgs
Add support to generate ondisk compression cfgs, which can generate
lz4 compression cfgs now.
Link: https://lore.kernel.org/r/20210411034844.12673-3-xiang@kernel.org
Signed-off-by: Gao Xiang <xiang@kernel.org>
diff --git a/include/erofs/compress.h b/include/erofs/compress.h
index 952f287..d234e8b 100644
--- a/include/erofs/compress.h
+++ b/include/erofs/compress.h
@@ -18,7 +18,7 @@
int erofs_write_compressed_file(struct erofs_inode *inode);
-int z_erofs_compress_init(void);
+int z_erofs_compress_init(struct erofs_buffer_head *bh);
int z_erofs_compress_exit(void);
const char *z_erofs_list_available_compressors(unsigned int i);
diff --git a/include/erofs/internal.h b/include/erofs/internal.h
index 3849980..6e481fa 100644
--- a/include/erofs/internal.h
+++ b/include/erofs/internal.h
@@ -79,6 +79,8 @@
u64 inos;
u8 uuid[16];
+
+ u16 available_compr_algs;
u16 lz4_max_distance;
};
@@ -105,6 +107,7 @@
}
EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
+EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
#define EROFS_I_EA_INITED (1 << 0)
diff --git a/include/erofs_fs.h b/include/erofs_fs.h
index ae2305c..a24deb0 100644
--- a/include/erofs_fs.h
+++ b/include/erofs_fs.h
@@ -20,7 +20,10 @@
* be incompatible with this kernel version.
*/
#define EROFS_FEATURE_INCOMPAT_LZ4_0PADDING 0x00000001
-#define EROFS_ALL_FEATURE_INCOMPAT EROFS_FEATURE_INCOMPAT_LZ4_0PADDING
+#define EROFS_FEATURE_INCOMPAT_COMPR_CFGS 0x00000002
+#define EROFS_ALL_FEATURE_INCOMPAT \
+ (EROFS_FEATURE_INCOMPAT_LZ4_0PADDING | \
+ EROFS_FEATURE_INCOMPAT_COMPR_CFGS)
/* 128-byte erofs on-disk super block */
struct erofs_super_block {
@@ -41,7 +44,11 @@
__u8 uuid[16]; /* 128-bit uuid for volume */
__u8 volume_name[16]; /* volume name */
__le32 feature_incompat;
- __le16 lz4_max_distance;
+ union {
+ /* bitmap for available compression algorithms */
+ __le16 available_compr_algs;
+ __le16 lz4_max_distance;
+ } u1;
__u8 reserved2[42];
};
@@ -198,6 +205,12 @@
Z_EROFS_COMPRESSION_MAX
};
+/* 14 bytes (+ length field = 16 bytes) */
+struct z_erofs_lz4_cfgs {
+ __le16 max_distance;
+ u8 reserved[12];
+} __packed;
+
/*
* bit 0 : COMPACTED_2B indexes (0 - off; 1 - on)
* e.g. for 4k logical cluster size, 4B if compacted 2B is off;
diff --git a/lib/compress.c b/lib/compress.c
index 4b685cd..c991c13 100644
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -500,7 +500,37 @@
return -ENOTSUP;
}
-int z_erofs_compress_init(void)
+int z_erofs_build_compr_cfgs(struct erofs_buffer_head *sb_bh)
+{
+ struct erofs_buffer_head *bh = sb_bh;
+ int ret = 0;
+
+ if (sbi.available_compr_algs & (1 << Z_EROFS_COMPRESSION_LZ4)) {
+ struct {
+ __le16 size;
+ struct z_erofs_lz4_cfgs lz4;
+ } __packed lz4alg = {
+ .size = cpu_to_le16(sizeof(struct z_erofs_lz4_cfgs)),
+ .lz4 = {
+ .max_distance =
+ cpu_to_le16(sbi.lz4_max_distance),
+ }
+ };
+
+ bh = erofs_battach(bh, META, sizeof(lz4alg));
+ if (IS_ERR(bh)) {
+ DBG_BUGON(1);
+ return PTR_ERR(bh);
+ }
+ erofs_mapbh(bh->block);
+ ret = dev_write(&lz4alg, erofs_btell(bh, false),
+ sizeof(lz4alg));
+ bh->op = &erofs_drop_directly_bhops;
+ }
+ return ret;
+}
+
+int z_erofs_compress_init(struct erofs_buffer_head *sb_bh)
{
unsigned int algorithmtype[2];
/* initialize for primary compression algorithm */
@@ -536,6 +566,11 @@
mapheader.h_algorithmtype = algorithmtype[1] << 4 |
algorithmtype[0];
mapheader.h_clusterbits = LOG_BLOCK_SIZE - 12;
+
+ if (erofs_sb_has_compr_cfgs()) {
+ sbi.available_compr_algs |= 1 << ret;
+ return z_erofs_build_compr_cfgs(sb_bh);
+ }
return 0;
}
diff --git a/mkfs/main.c b/mkfs/main.c
index 8a9611f..45709d7 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -322,7 +322,6 @@
.feature_incompat = cpu_to_le32(sbi.feature_incompat),
.feature_compat = cpu_to_le32(sbi.feature_compat &
~EROFS_FEATURE_COMPAT_SB_CHKSUM),
- .lz4_max_distance = cpu_to_le16(sbi.lz4_max_distance),
};
const unsigned int sb_blksize =
round_up(EROFS_SUPER_END, EROFS_BLKSIZ);
@@ -333,6 +332,11 @@
sb.root_nid = cpu_to_le16(root_nid);
memcpy(sb.uuid, sbi.uuid, sizeof(sb.uuid));
+ if (erofs_sb_has_compr_cfgs())
+ sb.u1.available_compr_algs = sbi.available_compr_algs;
+ else
+ sb.u1.lz4_max_distance = cpu_to_le16(sbi.lz4_max_distance);
+
buf = calloc(sb_blksize, 1);
if (!buf) {
erofs_err("Failed to allocate memory for sb: %s",
@@ -522,7 +526,7 @@
goto exit;
}
- err = z_erofs_compress_init();
+ err = z_erofs_compress_init(sb_bh);
if (err) {
erofs_err("Failed to initialize compressor: %s",
erofs_strerror(err));