[RFC PATCH v3 1/2] erofs-utils: support tail-packing inline compressed data

Yue Hu huyue2 at yulong.com
Wed Nov 17 20:22:00 AEDT 2021


Currently, we only support tail-end inline data for uncompressed
files, let's support it as well for compressed files.

The idea is from Xiang.

Signed-off-by: Yue Hu <huyue2 at yulong.com>
---
v3:
- based on commit 9fe440d0ac03 ("erofs-utils: mkfs: introduce --quiet option").
- move h_idata_size ahead of h_advise for compatibility.
- rename feature/update messages which i think they are more exact.

v2:
- add 2 bytes to record compressed size of tail-pcluster suggested from
  Xiang and update related code.

 include/erofs/internal.h |  1 +
 include/erofs_fs.h       | 10 ++++-
 lib/compress.c           | 83 ++++++++++++++++++++++++++++++----------
 lib/compressor.c         |  9 +++--
 lib/decompress.c         |  4 ++
 lib/inode.c              | 42 ++++++++++----------
 mkfs/main.c              |  7 ++++
 7 files changed, 108 insertions(+), 48 deletions(-)

diff --git a/include/erofs/internal.h b/include/erofs/internal.h
index 8b154ed..54e5939 100644
--- a/include/erofs/internal.h
+++ b/include/erofs/internal.h
@@ -110,6 +110,7 @@ EROFS_FEATURE_FUNCS(lz4_0padding, incompat, INCOMPAT_LZ4_0PADDING)
 EROFS_FEATURE_FUNCS(compr_cfgs, incompat, INCOMPAT_COMPR_CFGS)
 EROFS_FEATURE_FUNCS(big_pcluster, incompat, INCOMPAT_BIG_PCLUSTER)
 EROFS_FEATURE_FUNCS(chunked_file, incompat, INCOMPAT_CHUNKED_FILE)
+EROFS_FEATURE_FUNCS(tail_packing, incompat, INCOMPAT_TAIL_PACKING)
 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 66a68e3..0ebcd5b 100644
--- a/include/erofs_fs.h
+++ b/include/erofs_fs.h
@@ -22,11 +22,13 @@
 #define EROFS_FEATURE_INCOMPAT_COMPR_CFGS	0x00000002
 #define EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER	0x00000002
 #define EROFS_FEATURE_INCOMPAT_CHUNKED_FILE	0x00000004
+#define EROFS_FEATURE_INCOMPAT_TAIL_PACKING	0x00000010
 #define EROFS_ALL_FEATURE_INCOMPAT		\
 	(EROFS_FEATURE_INCOMPAT_LZ4_0PADDING | \
 	 EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
 	 EROFS_FEATURE_INCOMPAT_BIG_PCLUSTER | \
-	 EROFS_FEATURE_INCOMPAT_CHUNKED_FILE)
+	 EROFS_FEATURE_INCOMPAT_CHUNKED_FILE | \
+	 EROFS_FEATURE_INCOMPAT_TAIL_PACKING)
 
 #define EROFS_SB_EXTSLOT_SIZE	16
 
@@ -266,13 +268,17 @@ struct z_erofs_lz4_cfgs {
  *                                  (4B) + 2B + (4B) if compacted 2B is on.
  * bit 1 : HEAD1 big pcluster (0 - off; 1 - on)
  * bit 2 : HEAD2 big pcluster (0 - off; 1 - on)
+ * bit 3 : tail-packing inline (un)compressed data
  */
 #define Z_EROFS_ADVISE_COMPACTED_2B		0x0001
 #define Z_EROFS_ADVISE_BIG_PCLUSTER_1		0x0002
 #define Z_EROFS_ADVISE_BIG_PCLUSTER_2		0x0004
+#define Z_EROFS_ADVISE_INLINE_DATA		0x0008
 
 struct z_erofs_map_header {
-	__le32	h_reserved1;
+	__le16	h_reserved1;
+	/* record the (un)compressed size of tail-packing pcluster */
+	__le16	h_idata_size;
 	__le16	h_advise;
 	/*
 	 * bit 0-3 : algorithm type of head 1 (logical cluster type 01);
diff --git a/lib/compress.c b/lib/compress.c
index 6ca5bed..d7d60b9 100644
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -70,11 +70,10 @@ static void vle_write_indexes(struct z_erofs_vle_compress_ctx *ctx,
 
 	di.di_clusterofs = cpu_to_le16(ctx->clusterofs);
 
-	/* whether the tail-end uncompressed block or not */
+	/* whether the tail-end (un)compressed block or not */
 	if (!d1) {
-		/* TODO: tail-packing inline compressed data */
-		DBG_BUGON(!raw);
-		type = Z_EROFS_VLE_CLUSTER_TYPE_PLAIN;
+		type = raw ? Z_EROFS_VLE_CLUSTER_TYPE_PLAIN :
+			Z_EROFS_VLE_CLUSTER_TYPE_HEAD;
 		advise = cpu_to_le16(type << Z_EROFS_VLE_DI_CLUSTER_TYPE_BIT);
 
 		di.di_advise = advise;
@@ -162,6 +161,17 @@ static unsigned int z_erofs_get_max_pclusterblks(struct erofs_inode *inode)
 	return cfg.c_pclusterblks_def;
 }
 
+static int z_erofs_fill_inline_data(struct erofs_inode *inode, char *data,
+				    unsigned int len)
+{
+	inode->idata_size = len;
+	inode->idata = malloc(inode->idata_size);
+	if (!inode->idata)
+		return -ENOMEM;
+	memcpy(inode->idata, data, inode->idata_size);
+	return 0;
+}
+
 static int vle_compress_one(struct erofs_inode *inode,
 			    struct z_erofs_vle_compress_ctx *ctx,
 			    bool final)
@@ -172,15 +182,20 @@ static int vle_compress_one(struct erofs_inode *inode,
 	int ret;
 	static char dstbuf[EROFS_CONFIG_COMPR_MAX_SZ + EROFS_BLKSIZ];
 	char *const dst = dstbuf + EROFS_BLKSIZ;
+	bool tail_pcluster = false;
 
 	while (len) {
-		const unsigned int pclustersize =
+		unsigned int pclustersize =
 			z_erofs_get_max_pclusterblks(inode) * EROFS_BLKSIZ;
 		bool raw;
 
-		if (len <= pclustersize) {
+		if (!tail_pcluster && len <= pclustersize) {
 			if (final) {
-				if (len <= EROFS_BLKSIZ)
+				/* TODO: compress with 2 pclusters */
+				if (erofs_sb_has_tail_packing()) {
+					tail_pcluster = true;
+					pclustersize = EROFS_BLKSIZ;
+				} else if (len <= EROFS_BLKSIZ)
 					goto nocompression;
 			} else {
 				break;
@@ -196,6 +211,16 @@ static int vle_compress_one(struct erofs_inode *inode,
 					  inode->i_srcpath,
 					  erofs_strerror(ret));
 			}
+			if (tail_pcluster && len < EROFS_BLKSIZ) {
+				ret = z_erofs_fill_inline_data(inode,
+					(char *)(ctx->queue + ctx->head), len);
+				if (ret)
+					return ret;
+				count = len;
+				raw = true;
+				ctx->compressedblks = 1;
+				goto add_head;
+			}
 nocompression:
 			ret = write_uncompressed_extent(ctx, &len, dst);
 			if (ret < 0)
@@ -204,6 +229,15 @@ nocompression:
 			ctx->compressedblks = 1;
 			raw = true;
 		} else {
+			if (tail_pcluster && ret < EROFS_BLKSIZ &&
+			    !(len - count)) {
+				ret = z_erofs_fill_inline_data(inode, dst, ret);
+				if (ret)
+					return ret;
+				raw = false;
+				ctx->compressedblks = 1;
+				goto add_head;
+			}
 			const unsigned int tailused = ret & (EROFS_BLKSIZ - 1);
 			const unsigned int padding =
 				erofs_sb_has_lz4_0padding() && tailused ?
@@ -228,11 +262,13 @@ nocompression:
 			raw = false;
 		}
 
+add_head:
 		ctx->head += count;
 		/* write compression indexes for this pcluster */
 		vle_write_indexes(ctx, count, raw);
 
-		ctx->blkaddr += ctx->compressedblks;
+		if (!inode->idata_size)
+			ctx->blkaddr += ctx->compressedblks;
 		len -= count;
 
 		if (!final && ctx->head >= EROFS_CONFIG_COMPR_MAX_SZ) {
@@ -449,6 +485,7 @@ static void z_erofs_write_mapheader(struct erofs_inode *inode,
 {
 	struct z_erofs_map_header h = {
 		.h_advise = cpu_to_le16(inode->z_advise),
+		.h_idata_size = cpu_to_le16(inode->idata_size),
 		.h_algorithmtype = inode->z_algorithmtype[1] << 4 |
 				   inode->z_algorithmtype[0],
 		/* lclustersize */
@@ -476,7 +513,7 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
 	fd = open(inode->i_srcpath, O_RDONLY | O_BINARY);
 	if (fd < 0) {
 		ret = -errno;
-		goto err_free;
+		goto err_free_meta;
 	}
 
 	/* allocate main data buffer */
@@ -504,8 +541,6 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
 	inode->z_algorithmtype[1] = algorithmtype[1];
 	inode->z_logical_clusterbits = LOG_BLOCK_SIZE;
 
-	z_erofs_write_mapheader(inode, compressmeta);
-
 	blkaddr = erofs_mapbh(bh->block);	/* start_blkaddr */
 	ctx.blkaddr = blkaddr;
 	ctx.metacur = compressmeta + Z_EROFS_LEGACY_MAP_HEADER_SIZE;
@@ -531,19 +566,23 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
 			goto err_bdrop;
 	}
 
+	inode->idata_size = 0;
+
 	/* do the final round */
 	ret = vle_compress_one(inode, &ctx, true);
 	if (ret)
-		goto err_bdrop;
+		goto err_free_id;
 
 	/* fall back to no compression mode */
 	compressed_blocks = ctx.blkaddr - blkaddr;
-	if (compressed_blocks >= BLK_ROUND_UP(inode->i_size)) {
+	if (compressed_blocks >= BLK_ROUND_UP(inode->i_size) -
+	    (inode->idata_size ? 1 : 0)) {
 		ret = -ENOSPC;
-		goto err_bdrop;
+		goto err_free_id;
 	}
 
 	vle_write_indexes_final(&ctx);
+	z_erofs_write_mapheader(inode, compressmeta);
 
 	close(fd);
 	DBG_BUGON(!compressed_blocks);
@@ -554,12 +593,11 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
 		   inode->i_srcpath, (unsigned long long)inode->i_size,
 		   compressed_blocks);
 
-	/*
-	 * TODO: need to move erofs_bdrop to erofs_write_tail_end
-	 *       when both mkfs & kernel support compression inline.
-	 */
-	erofs_bdrop(bh, false);
-	inode->idata_size = 0;
+	if (inode->idata_size)
+		inode->bh_data = bh;
+	else
+		erofs_bdrop(bh, false);
+
 	inode->u.i_blocks = compressed_blocks;
 
 	legacymetasize = ctx.metacur - compressmeta;
@@ -575,11 +613,14 @@ int erofs_write_compressed_file(struct erofs_inode *inode)
 	erofs_droid_blocklist_write(inode, blkaddr, compressed_blocks);
 	return 0;
 
+err_free_id:
+	if (inode->idata)
+		free(inode->idata);
 err_bdrop:
 	erofs_bdrop(bh, true);	/* revoke buffer */
 err_close:
 	close(fd);
-err_free:
+err_free_meta:
 	free(compressmeta);
 	return ret;
 }
diff --git a/lib/compressor.c b/lib/compressor.c
index 89c1be1..9b9d2ff 100644
--- a/lib/compressor.c
+++ b/lib/compressor.c
@@ -23,7 +23,7 @@ int erofs_compress_destsize(struct erofs_compress *c,
 			    void *src, unsigned int *srcsize,
 			    void *dst, unsigned int dstsize)
 {
-	unsigned int uncompressed_size;
+	unsigned int compressed_size;
 	int ret;
 
 	DBG_BUGON(!c->alg);
@@ -35,9 +35,10 @@ int erofs_compress_destsize(struct erofs_compress *c,
 		return ret;
 
 	/* check if there is enough gains to compress */
-	uncompressed_size = *srcsize;
-	if (roundup(ret, EROFS_BLKSIZ) >= uncompressed_size *
-	    c->compress_threshold / 100)
+	compressed_size = *srcsize <= EROFS_BLKSIZ ? ret :
+			  roundup(ret, EROFS_BLKSIZ);
+
+	if (*srcsize <= compressed_size * c->compress_threshold / 100)
 		return -EAGAIN;
 	return ret;
 }
diff --git a/lib/decompress.c b/lib/decompress.c
index 2ee1439..6f4ecc2 100644
--- a/lib/decompress.c
+++ b/lib/decompress.c
@@ -7,6 +7,7 @@
 
 #include "erofs/decompress.h"
 #include "erofs/err.h"
+#include "erofs/print.h"
 
 #ifdef LZ4_ENABLED
 #include <lz4.h>
@@ -48,6 +49,9 @@ static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq)
 					  rq->decodedlength);
 
 	if (ret != (int)rq->decodedlength) {
+		erofs_err("failed to %s decompress %d in[%u, %u] out[%u]",
+			  rq->partial_decoding ? "partial" : "full",
+			  ret, rq->inputsize, inputmargin, rq->decodedlength);
 		ret = -EIO;
 		goto out;
 	}
diff --git a/lib/inode.c b/lib/inode.c
index 6597a26..b9dcb08 100644
--- a/lib/inode.c
+++ b/lib/inode.c
@@ -549,9 +549,6 @@ static int erofs_prepare_tail_block(struct erofs_inode *inode)
 	struct erofs_buffer_head *bh;
 	int ret;
 
-	if (!inode->idata_size)
-		return 0;
-
 	bh = inode->bh_data;
 	if (!bh) {
 		bh = erofs_balloc(DATA, EROFS_BLKSIZ, 0, 0);
@@ -585,8 +582,9 @@ static int erofs_prepare_inode_buffer(struct erofs_inode *inode)
 		inodesize = Z_EROFS_VLE_EXTENT_ALIGN(inodesize) +
 			    inode->extent_isize;
 
-	if (is_inode_layout_compression(inode))
+	if (!inode->idata_size)
 		goto noinline;
+
 	if (inode->datalayout == EROFS_INODE_CHUNK_BASED)
 		goto noinline;
 
@@ -595,23 +593,18 @@ static int erofs_prepare_inode_buffer(struct erofs_inode *inode)
 		goto noinline;
 	}
 
-	/*
-	 * if the file size is block-aligned for uncompressed files,
-	 * should use EROFS_INODE_FLAT_PLAIN data mapping mode.
-	 */
-	if (!inode->idata_size)
-		inode->datalayout = EROFS_INODE_FLAT_PLAIN;
-
 	bh = erofs_balloc(INODE, inodesize, 0, inode->idata_size);
 	if (bh == ERR_PTR(-ENOSPC)) {
 		int ret;
 
-		inode->datalayout = EROFS_INODE_FLAT_PLAIN;
-noinline:
 		/* expend an extra block for tail-end data */
 		ret = erofs_prepare_tail_block(inode);
 		if (ret)
 			return ret;
+noinline:
+		if (!is_inode_layout_compression(inode))
+			inode->datalayout = EROFS_INODE_FLAT_PLAIN;
+
 		bh = erofs_balloc(INODE, inodesize, 0, 0);
 		if (IS_ERR(bh))
 			return PTR_ERR(bh);
@@ -619,7 +612,15 @@ noinline:
 	} else if (IS_ERR(bh)) {
 		return PTR_ERR(bh);
 	} else if (inode->idata_size) {
-		inode->datalayout = EROFS_INODE_FLAT_INLINE;
+		if (is_inode_layout_compression(inode)) {
+			struct z_erofs_map_header *h = inode->compressmeta;
+
+			h->h_advise |= Z_EROFS_ADVISE_INLINE_DATA;
+			erofs_dbg("%s: inline data (%u bytes)",
+				  inode->i_srcpath, inode->idata_size);
+		} else {
+			inode->datalayout = EROFS_INODE_FLAT_INLINE;
+		}
 
 		/* allocate inline buffer */
 		ibh = erofs_battach(bh, META, inode->idata_size);
@@ -684,13 +685,12 @@ static int erofs_write_tail_end(struct erofs_inode *inode)
 		ret = dev_write(inode->idata, pos, inode->idata_size);
 		if (ret)
 			return ret;
-		if (inode->idata_size < EROFS_BLKSIZ) {
-			ret = dev_fillzero(pos + inode->idata_size,
-					   EROFS_BLKSIZ - inode->idata_size,
-					   false);
-			if (ret)
-				return ret;
-		}
+		ret = dev_fillzero(pos + inode->idata_size,
+				   EROFS_BLKSIZ - inode->idata_size,
+				   false);
+		if (ret)
+			return ret;
+
 		inode->idata_size = 0;
 		free(inode->idata);
 		inode->idata = NULL;
diff --git a/mkfs/main.c b/mkfs/main.c
index 055d077..7505ff6 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -47,6 +47,7 @@ static struct option long_options[] = {
 	{"compress-hints", required_argument, NULL, 10},
 	{"chunksize", required_argument, NULL, 11},
 	{"quiet", no_argument, 0, 12},
+	{"inline-data", no_argument, NULL, 13},
 #ifdef WITH_ANDROID
 	{"mount-point", required_argument, NULL, 512},
 	{"product-out", required_argument, NULL, 513},
@@ -95,6 +96,7 @@ static void usage(void)
 	      " --help                display this help and exit\n"
 	      " --max-extent-bytes=#  set maximum decompressed extent size # in bytes\n"
 	      " --quiet               quiet execution (do not write anything to standard output.)\n"
+	      " --inline-data         tail-packing inline compressed data\n"
 #ifndef NDEBUG
 	      " --random-pclusterblks randomize pclusterblks for big pcluster (debugging only)\n"
 #endif
@@ -349,6 +351,9 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
 		case 12:
 			quiet = true;
 			break;
+		case 13:
+			erofs_sb_set_tail_packing();
+			break;
 		case 1:
 			usage();
 			exit(0);
@@ -607,6 +612,8 @@ int main(int argc, char **argv)
 	erofs_show_config();
 	if (erofs_sb_has_chunked_file())
 		erofs_warn("EXPERIMENTAL chunked file feature in use. Use at your own risk!");
+	if (erofs_sb_has_tail_packing())
+		erofs_warn("EXPERIMENTAL compression inline data feature in use. Use at your own risk!");
 	erofs_set_fs_root(cfg.c_src_path);
 #ifndef NDEBUG
 	if (cfg.c_random_pclusterblks)
-- 
2.17.1





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