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Date:   Tue, 8 Dec 2020 12:18:25 -0800
From:   Jaegeuk Kim <jaegeuk@kernel.org>
To:     Robin Hsu <robinh3123@gmail.com>
Cc:     linux-f2fs-devel@lists.sourceforge.net, chao@kernel.org,
        linux-kernel@vger.kernel.org, Robin Hsu <robinhsu@google.com>
Subject: Re: [PATCH v3 2/3] f2fs-tools:sload.f2fs compression support
Message-ID: <X8/fkR8pjef1I6Q9@google.com>
References: <20201208081555.652932-1-robinh3123@gmail.com>
 <20201208081555.652932-3-robinh3123@gmail.com>
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In-Reply-To: <20201208081555.652932-3-robinh3123@gmail.com>
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Hi Robin,

I found some bugs and want to suggest a fix.
I'll apply this on your patch and let me know, if you want to modify more on top
of this.

--- a/fsck/segment.c
+++ b/fsck/segment.c
@@ -115,6 +115,8 @@ int new_data_block(struct f2fs_sb_info *sbi, void *block,

        get_node_info(sbi, dn->nid, &ni);
        set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
+
+       dn->data_blkaddr = blkaddr;
        ret = reserve_new_block(sbi, &dn->data_blkaddr, &sum, type, 0);
        if (ret) {
                c.alloc_failed = 1;
@@ -517,8 +519,8 @@ int f2fs_build_file(struct f2fs_sb_info *sbi, struct dentry *de)
                                        COMPRESS_HEADER_SIZE, BLOCK_SZ);
                        unsigned int cur_cblk;

-                       if (ret || n < (int)(csize + BLOCK_SZ *
-                                               c.sldc_min_cbpc)) {
+                       if (ret || n < (1 << c.sldc_cc.log_cluster_size) * BLOCK_SZ ||
+                               n < (int)(csize + BLOCK_SZ * c.sldc_min_cbpc)) {
                                wlen = f2fs_write(sbi, de->ino, rbuf, n, off);
                                ASSERT((int)wlen == n);
                        } else {
@@ -549,8 +551,10 @@ int f2fs_build_file(struct f2fs_sb_info *sbi, struct dentry *de)
                ASSERT(dev_read_block(node_blk, ni.blk_addr) >= 0);
                /* update inode meta */
                node_blk->i.i_size = cpu_to_le64(off);
-               if (!c.sldc_immutable)
+               if (!c.sldc_immutable) {
                        node_blk->i.i_compr_blocks = cpu_to_le64(cblocks);
+                       node_blk->i.i_blocks += cpu_to_le64(cblocks);
+               }
                ASSERT(write_inode(node_blk, ni.blk_addr) >= 0);
                free(node_blk);


On 12/08, Robin Hsu wrote:
> From: Robin Hsu <robinhsu@google.com>
> 
> Add F2FS compression support for sload
> * Support file extension filter, either default-accept or default-deny
>   policy
> * Support choice of compression algorithm, LZO (version 2) or LZ4
>   (default)
> * Support custom log of cluster size
> * Support minimum number of compressed blocks per cluster (default 1).
>   A cluster will not be compressed if the number can not be met.
> * suuport -r (read-only) option
> 
> Signed-off-by: Robin Hsu <robinhsu@google.com>
> ---
>  fsck/compress_wrapper.c | 102 ++++++++++++++++++++
>  fsck/compress_wrapper.h |  22 +++++
>  fsck/fsck.h             |  15 +++
>  fsck/main.c             | 141 +++++++++++++++++++++++++++-
>  fsck/segment.c          | 202 +++++++++++++++++++++++++++++++++++++---
>  fsck/sload.c            |  67 +++++++++++++
>  include/f2fs_fs.h       |  76 ++++++++++++++-
>  lib/libf2fs_io.c        |  33 +++++++
>  8 files changed, 644 insertions(+), 14 deletions(-)
>  create mode 100644 fsck/compress_wrapper.c
>  create mode 100644 fsck/compress_wrapper.h
> 
> diff --git a/fsck/compress_wrapper.c b/fsck/compress_wrapper.c
> new file mode 100644
> index 0000000..2cdc4fd
> --- /dev/null
> +++ b/fsck/compress_wrapper.c
> @@ -0,0 +1,102 @@
> +/**
> + * compress_wrapper.c
> + *
> + * Copyright (c) 2020 Google Inc.
> + *   Robin Hsu <robinhsu@google.com>
> + *   : initial created, for sload compression support
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +#include "f2fs.h" /* for config.h for general environment (non-Android) */
> +
> +#include "compress_wrapper.h"
> +#ifdef HAVE_LIBLZO2
> +#include <lzo/lzo1x.h> /* for lzo1x_1_15_compress() */
> +#endif
> +#ifdef HAVE_LIBLZ4
> +#include <lz4.h> /* for LZ4_compress_fast_extState() */
> +#endif
> +
> +/*
> + * macro/constants borrowed from kernel header (GPL-2.0):
> + * include/linux/lzo.h, and include/linux/lz4.h
> + */
> +#ifdef HAVE_LIBLZO2
> +#define lzo1x_worst_compress(x)		((x) + (x) / 16 + 64 + 3 + 2)
> +#define LZO_WORK_SIZE			ALIGN_UP(LZO1X_1_15_MEM_COMPRESS, 8)
> +#endif
> +#ifdef HAVE_LIBLZ4
> +#define LZ4_MEMORY_USAGE		14
> +#define LZ4_MAX_INPUT_SIZE		0x7E000000 /* 2 113 929 216 bytes */
> +#define LZ4_STREAMSIZE			(LZ4_STREAMSIZE_U64 * sizeof(long long))
> +#define LZ4_MEM_COMPRESS		LZ4_STREAMSIZE
> +#define LZ4_ACCELERATION_DEFAULT	1
> +#define LZ4_WORK_SIZE			ALIGN_UP(LZ4_MEM_COMPRESS, 8)
> +#endif
> +
> +#ifdef HAVE_LIBLZO2
> +static void lzo_compress_init(struct compress_ctx *cc)
> +{
> +	size_t size = cc->cluster_size * F2FS_BLKSIZE;
> +	size_t alloc = size + lzo1x_worst_compress(size)
> +			+ COMPRESS_HEADER_SIZE + LZO_WORK_SIZE;
> +	ASSERT((cc->private = qbuf_alloc(alloc)) != NULL);
> +	cc->rbuf = (char *) cc->private + LZO_WORK_SIZE;
> +	cc->cbuf = (struct compress_data *)((char *) cc->rbuf + size);
> +}
> +
> +static int lzo_compress(struct compress_ctx *cc)
> +{
> +	int ret = lzo1x_1_15_compress(cc->rbuf, cc->rlen, cc->cbuf->cdata,
> +			(lzo_uintp)(&cc->clen), cc->private);
> +	cc->cbuf->clen = cpu_to_le32(cc->clen);
> +	return ret;
> +}
> +#endif
> +
> +#ifdef HAVE_LIBLZ4
> +static void lz4_compress_init(struct compress_ctx *cc)
> +{
> +	size_t size = cc->cluster_size * F2FS_BLKSIZE;
> +	size_t alloc = size + LZ4_COMPRESSBOUND(size)
> +			+ COMPRESS_HEADER_SIZE + LZ4_WORK_SIZE;
> +	ASSERT((cc->private = qbuf_alloc(alloc)) != NULL);
> +	cc->rbuf = (char *) cc->private + LZ4_WORK_SIZE;
> +	cc->cbuf = (struct compress_data *)((char *) cc->rbuf + size);
> +}
> +
> +static int lz4_compress(struct compress_ctx *cc)
> +{
> +	cc->clen = LZ4_compress_fast_extState(cc->private, cc->rbuf,
> +			(char *)cc->cbuf->cdata, cc->rlen,
> +			cc->rlen - F2FS_BLKSIZE * c.sldc_min_cbpc,
> +			LZ4_ACCELERATION_DEFAULT);
> +
> +	if (!cc->clen)
> +		return 1;
> +
> +	cc->cbuf->clen = cpu_to_le32(cc->clen);
> +	return 0;
> +}
> +#endif
> +
> +const char *ca_names[] = {
> +	"LZO",
> +	"LZ4",
> +	"", /* end of the name list */
> +};
> +
> +compress_ops compr_ops[] = {
> +#ifdef HAVE_LIBLZO2
> +	{lzo_compress_init, lzo_compress},
> +#else
> +	{NULL, NULL},
> +#endif
> +#ifdef HAVE_LIBLZ4
> +	{lz4_compress_init, lz4_compress},
> +#else
> +	{NULL, NULL},
> +#endif
> +};
> diff --git a/fsck/compress_wrapper.h b/fsck/compress_wrapper.h
> new file mode 100644
> index 0000000..ec33d43
> --- /dev/null
> +++ b/fsck/compress_wrapper.h
> @@ -0,0 +1,22 @@
> +/**
> + * compress_wrapper.h
> + *
> + * Copyright (c) 2020 Google Inc.
> + *   Robin Hsu <robinhsu@google.com>
> + *   : initial created, for sload compression support
> + * Copyright (c) 2020 Google Inc.
> + *   Robin Hsu <robinhsu@google.com>
> + *  : add sload compression support
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef COMPRESS_WRAPPER_H
> +#define COMPRESS_WRAPPER_H
> +
> +#include "f2fs_fs.h"
> +extern compress_ops compr_ops[]; /* [0]: LZO, [1]: LZ4, */
> +
> +#endif /* COMPRESS_WRAPPER_H */
> diff --git a/fsck/fsck.h b/fsck/fsck.h
> index c5e85fe..4e866ec 100644
> --- a/fsck/fsck.h
> +++ b/fsck/fsck.h
> @@ -3,6 +3,9 @@
>   *
>   * Copyright (c) 2013 Samsung Electronics Co., Ltd.
>   *             http://www.samsung.com/
> + * Copyright (c) 2020 Google Inc.
> + *   Robin Hsu <robinhsu@google.com>
> + *  : add sload compression support
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License version 2 as
> @@ -266,6 +269,9 @@ int f2fs_resize(struct f2fs_sb_info *);
>  
>  /* sload.c */
>  int f2fs_sload(struct f2fs_sb_info *);
> +void sldc_erase_bufs(struct compress_ctx *cc);
> +void sload_countblk(void);
> +extern struct ext_tbl_op ext_filter;
>  
>  /* segment.c */
>  int reserve_new_block(struct f2fs_sb_info *, block_t *,
> @@ -282,7 +288,16 @@ block_t new_node_block(struct f2fs_sb_info *,
>  struct quota_file;
>  u64 f2fs_quota_size(struct quota_file *);
>  u64 f2fs_read(struct f2fs_sb_info *, nid_t, u8 *, u64, pgoff_t);
> +enum wr_addr_type {
> +	WR_NORMAL = 1,
> +	WR_COMPRESS_DATA = 2,
> +	WR_NULL_ADDR = NULL_ADDR,  /* 0 */
> +	WR_NEW_ADDR = NEW_ADDR, /* -1U */
> +	WR_COMPRESS_ADDR = COMPRESS_ADDR, /* -2U */
> +};
>  u64 f2fs_write(struct f2fs_sb_info *, nid_t, u8 *, u64, pgoff_t);
> +u64 f2fs_write_compress_data(struct f2fs_sb_info *, nid_t, u8 *, u64, pgoff_t);
> +u64 f2fs_write_addrtag(struct f2fs_sb_info *, nid_t, pgoff_t, unsigned int);
>  void f2fs_filesize_update(struct f2fs_sb_info *, nid_t, u64);
>  
>  int get_dnode_of_data(struct f2fs_sb_info *, struct dnode_of_data *,
> diff --git a/fsck/main.c b/fsck/main.c
> index b20498f..001eed0 100644
> --- a/fsck/main.c
> +++ b/fsck/main.c
> @@ -13,6 +13,9 @@
>   * Copyright (c) 2019 Google Inc.
>   *   Robin Hsu <robinhsu@google.com>
>   *  : add cache layer
> + * Copyright (c) 2020 Google Inc.
> + *   Robin Hsu <robinhsu@google.com>
> + *  : add sload compression support
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License version 2 as
> @@ -25,6 +28,7 @@
>  #include <getopt.h>
>  #include <stdbool.h>
>  #include "quotaio.h"
> +#include "compress_wrapper.h"
>  
>  struct f2fs_fsck gfsck;
>  
> @@ -134,6 +138,17 @@ void sload_usage()
>  	MSG(0, "  -S sparse_mode\n");
>  	MSG(0, "  -t mount point [prefix of target fs path, default:/]\n");
>  	MSG(0, "  -T timestamp\n");
> +	MSG(0, "  -c enable compression (default allow policy)\n");
> +	MSG(0, "    ------------ Compression sub-options -----------------\n");
> +	MSG(0, "    -L <log-of-blocks-per-cluster>, default 2\n");
> +	MSG(0, "    -a <algorithm> compression algorithm, default LZ4\n");
> +	MSG(0, "    -x <ext> compress files except for these extensions.\n");
> +	MSG(0, "    -i <ext> compress files with these extensions only.\n");
> +	MSG(0, "    * -i or -x: use it many times for multiple extensions.\n");
> +	MSG(0, "    * -i and -x cannot be used together..\n");
> +	MSG(0, "    -m <num> min compressed blocks per cluster\n");
> +	MSG(0, "    -r readonly (IMMUTABLE) for compressed files\n");
> +	MSG(0, "    ------------------------------------------------------\n");
>  	MSG(0, "  -d debug level [default:0]\n");
>  	MSG(0, "  -V print the version number and exit\n");
>  	exit(1);
> @@ -534,7 +549,7 @@ void f2fs_parse_options(int argc, char *argv[])
>  #endif
>  	} else if (!strcmp("sload.f2fs", prog)) {
>  #ifdef WITH_SLOAD
> -		const char *option_string = "C:d:f:p:s:St:T:V";
> +		const char *option_string = "cL:a:i:x:m:rC:d:f:p:s:St:T:V";
>  #ifdef HAVE_LIBSELINUX
>  		int max_nr_opt = (int)sizeof(c.seopt_file) /
>  			sizeof(c.seopt_file[0]);
> @@ -543,8 +558,82 @@ void f2fs_parse_options(int argc, char *argv[])
>  		char *p;
>  
>  		c.func = SLOAD;
> +		c.sldc_cc.log_cluster_size = 2;
> +		c.sldc_ca = CA_LZ4;
> +		c.sldc_min_cbpc = 1;
> +		c.sldc_ef = &ext_filter;
>  		while ((option = getopt(argc, argv, option_string)) != EOF) {
> +			unsigned int i;
> +			int val;
> +
>  			switch (option) {
> +			case 'c': /* compression support */
> +				c.sldc_en = true;
> +				break;
> +			case 'L': /* compression: log of blocks-per-cluster */
> +				c.sldc_got_opt = true;
> +				val = atoi(optarg);
> +				if (val < MIN_COMPRESS_LOG_SIZE ||
> +						val > MAX_COMPRESS_LOG_SIZE) {
> +					MSG(0, "\tError: log of blocks per"
> +						" cluster must be in the range"
> +						" of %d .. %d.\n",
> +						MIN_COMPRESS_LOG_SIZE,
> +						MAX_COMPRESS_LOG_SIZE);
> +					error_out(prog);
> +				}
> +				c.sldc_cc.log_cluster_size = val;
> +				break;
> +			case 'a': /* compression: choose algorithm */
> +				c.sldc_got_opt = true;
> +				c.sldc_ca = (u8)-1;
> +				for (i = 0; ca_names[i][0] != 0; i++) {
> +					if (!strcmp(ca_names[i], optarg)) {
> +						c.sldc_ca = i;
> +						break;
> +					}
> +				}
> +				if (c.sldc_ca == (u8)-1) {
> +					MSG(0, "\tError: Unknown compression"
> +						" algorithm %s\n", optarg);
> +					error_out(prog);
> +				}
> +				break;
> +			case 'i': /* compress only these extensions */
> +				c.sldc_got_opt = true;
> +				if (c.sldc_policy == FP_ALLOW) {
> +					MSG(0, "\tError: could not mix option"
> +							" -i and -x\n");
> +					error_out(prog);
> +				}
> +				c.sldc_policy = FP_DENY;
> +				c.sldc_ef->add(optarg);
> +				break;
> +			case 'x': /* compress except for these extensions */
> +				c.sldc_got_opt = true;
> +				if (c.sldc_policy == FP_DENY) {
> +					MSG(0, "\tError: could not mix option"
> +							" -i and -x\n");
> +					error_out(prog);
> +				}
> +				c.sldc_policy = FP_ALLOW;
> +				c.sldc_ef->add(optarg);
> +				break;
> +			case 'm': /* minimum compressed blocks per cluster */
> +				c.sldc_got_opt = true;
> +				val = atoi(optarg);
> +				if (val <= 0) {
> +					MSG(0, "\tError: minimum compressed"
> +						" blocks per cluster must be"
> +						" positive.\n");
> +					error_out(prog);
> +				}
> +				c.sldc_min_cbpc = val;
> +				break;
> +			case 'r': /* compress file to set IMMUTABLE */
> +				c.sldc_got_opt = true;
> +				c.sldc_immutable = true;
> +				break;
>  			case 'C':
>  				c.fs_config_file = absolute_path(optarg);
>  				break;
> @@ -602,6 +691,27 @@ void f2fs_parse_options(int argc, char *argv[])
>  			if (err != NOERROR)
>  				break;
>  		}
> +		if (c.sldc_got_opt && !c.sldc_en) {
> +			MSG(0, "\tError: compression sub-options are used"
> +				" without the compression enable (-c) option\n"
> +			);
> +			error_out(prog);
> +		}
> +		if (err == NOERROR && c.sldc_en) {
> +			c.sldc_cc.cluster_size = 1
> +				<< c.sldc_cc.log_cluster_size;
> +			if (c.sldc_policy == FP_UNASSIGNED)
> +				c.sldc_policy = FP_ALLOW;
> +			if (c.sldc_min_cbpc >= c.sldc_cc.cluster_size) {
> +				MSG(0, "\tError: minimum reduced blocks by"
> +					" compression per cluster must be at"
> +					" most one less than blocks per"
> +					" cluster, i.e. %d\n",
> +					c.sldc_cc.cluster_size - 1);
> +				error_out(prog);
> +			}
> +			qbuf_init();
> +		}
>  #endif /* WITH_SLOAD */
>  	}
>  
> @@ -812,6 +922,27 @@ static int do_resize(struct f2fs_sb_info *sbi)
>  #endif
>  
>  #ifdef WITH_SLOAD
> +int init_compr(struct f2fs_sb_info *sbi)
> +{
> +	if (!(sbi->raw_super->feature
> +			& cpu_to_le32(F2FS_FEATURE_COMPRESSION))) {
> +		MSG(0, "Error: Compression (-c) was requested "
> +			"but the file system is not created "
> +			"with such feature.\n");
> +		return -1;
> +	}
> +	if (compr_ops[c.sldc_ca].init == NULL) {
> +		MSG(0, "Error: The selected compression algorithm is not"
> +				" supported\n");
> +		return -1;
> +	}
> +	c.sldc_compr = compr_ops + c.sldc_ca;
> +	c.sldc_compr->init(&c.sldc_cc);
> +	sldc_erase_bufs(&c.sldc_cc);
> +	c.sldc_cc.rlen = c.sldc_cc.cluster_size * F2FS_BLKSIZE;
> +	return 0;
> +}
> +
>  static int do_sload(struct f2fs_sb_info *sbi)
>  {
>  	if (!c.from_dir) {
> @@ -821,6 +952,11 @@ static int do_sload(struct f2fs_sb_info *sbi)
>  	if (!c.mount_point)
>  		c.mount_point = "/";
>  
> +	if (c.sldc_en) {
> +		if (init_compr(sbi))
> +			return -1;
> +	}
> +
>  	return f2fs_sload(sbi);
>  }
>  #endif
> @@ -971,6 +1107,9 @@ retry:
>  		return ret2;
>  	}
>  
> +	if (c.func == SLOAD)
> +		c.sldc_ef->destroy();
> +
>  	printf("\nDone: %lf secs\n", (get_boottime_ns() - start) / 1000000000.0);
>  	return ret;
>  
> diff --git a/fsck/segment.c b/fsck/segment.c
> index 0487f41..e4c8cea 100644
> --- a/fsck/segment.c
> +++ b/fsck/segment.c
> @@ -8,6 +8,9 @@
>   *   Hou Pengyang <houpengyang@huawei.com>
>   *   Liu Shuoran <liushuoran@huawei.com>
>   *   Jaegeuk Kim <jaegeuk@kernel.org>
> + * Copyright (c) 2020 Google Inc.
> + *   Robin Hsu <robinhsu@google.com>
> + *  : add sload compression support
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License version 2 as
> @@ -16,6 +19,7 @@
>  #include "fsck.h"
>  #include "node.h"
>  #include "quotaio.h"
> +#include "compress_wrapper.h"
>  
>  int reserve_new_block(struct f2fs_sb_info *sbi, block_t *to,
>  			struct f2fs_summary *sum, int type, bool is_inode)
> @@ -228,8 +232,14 @@ u64 f2fs_read(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
>  	return read_count;
>  }
>  
> -u64 f2fs_write(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
> -					u64 count, pgoff_t offset)
> +/*
> + * Do not call this function directly.  Instead, call one of the following:
> + *     u64 f2fs_write();
> + *     u64 f2fs_write_compress_data();
> + *     u64 f2fs_write_addrtag();
> + */
> +static u64 f2fs_write_ex(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
> +		u64 count, pgoff_t offset, enum wr_addr_type addr_type)
>  {
>  	struct dnode_of_data dn;
>  	struct node_info ni;
> @@ -243,6 +253,19 @@ u64 f2fs_write(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
>  	void* index_node = NULL;
>  	int idirty = 0;
>  	int err;
> +	bool has_data = (addr_type == WR_NORMAL
> +			|| addr_type == WR_COMPRESS_DATA);
> +
> +	if (count == 0)
> +		return 0;
> +
> +	/*
> +	 * Enforce calling from f2fs_write(), f2fs_write_compress_data(),
> +	 * and f2fs_write_addrtag().   Beside, check if is properly called.
> +	 */
> +	ASSERT((!has_data && buffer == NULL) || (has_data && buffer != NULL));
> +	if (addr_type != WR_NORMAL)
> +		ASSERT(offset % F2FS_BLKSIZE == 0); /* block boundary only */
>  
>  	/* Memory allocation for block buffer and inode. */
>  	blk_buffer = calloc(BLOCK_SZ, 2);
> @@ -265,15 +288,26 @@ u64 f2fs_write(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
>  			if (err)
>  				break;
>  			idirty |= dn.idirty;
> -			if (index_node)
> -				free(index_node);
> +			free(index_node);
>  			index_node = (dn.node_blk == dn.inode_blk) ?
> -							NULL : dn.node_blk;
> +					NULL : dn.node_blk;
>  			remained_blkentries = ADDRS_PER_PAGE(sbi,
> -						dn.node_blk, dn.inode_blk);
> +					dn.node_blk, dn.inode_blk) -
> +					dn.ofs_in_node;
>  		}
>  		ASSERT(remained_blkentries > 0);
>  
> +		if (!has_data) {
> +			dn.data_blkaddr = addr_type;
> +			set_data_blkaddr(&dn);
> +			idirty |= dn.idirty;
> +			if (dn.ndirty)
> +				ASSERT(dev_write_block(dn.node_blk,
> +						dn.node_blkaddr) >= 0);
> +			written_count = 0;
> +			break;
> +		}
> +
>  		blkaddr = datablock_addr(dn.node_blk, dn.ofs_in_node);
>  		if (blkaddr == NULL_ADDR || blkaddr == NEW_ADDR) {
>  			err = new_data_block(sbi, blk_buffer,
> @@ -281,6 +315,7 @@ u64 f2fs_write(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
>  			if (err)
>  				break;
>  			blkaddr = dn.data_blkaddr;
> +			idirty |= dn.idirty;
>  		}
>  
>  		off_in_blk = offset % BLOCK_SZ;
> @@ -305,9 +340,10 @@ u64 f2fs_write(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
>  
>  		dn.ofs_in_node++;
>  		if ((--remained_blkentries == 0 || count == 0) && (dn.ndirty))
> -			ASSERT(dev_write_block(dn.node_blk, dn.node_blkaddr) >= 0);
> +			ASSERT(dev_write_block(dn.node_blk, dn.node_blkaddr)
> +					>= 0);
>  	}
> -	if (offset > le64_to_cpu(inode->i.i_size)) {
> +	if (addr_type == WR_NORMAL && offset > le64_to_cpu(inode->i.i_size)) {
>  		inode->i.i_size = cpu_to_le64(offset);
>  		idirty = 1;
>  	}
> @@ -315,13 +351,33 @@ u64 f2fs_write(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
>  		ASSERT(inode == dn.inode_blk);
>  		ASSERT(write_inode(inode, ni.blk_addr) >= 0);
>  	}
> -	if (index_node)
> -		free(index_node);
> +
> +	free(index_node);
>  	free(blk_buffer);
>  
>  	return written_count;
>  }
>  
> +u64 f2fs_write(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
> +					u64 count, pgoff_t offset)
> +{
> +	return f2fs_write_ex(sbi, ino, buffer, count, offset, WR_NORMAL);
> +}
> +
> +u64 f2fs_write_compress_data(struct f2fs_sb_info *sbi, nid_t ino, u8 *buffer,
> +					u64 count, pgoff_t offset)
> +{
> +	return f2fs_write_ex(sbi, ino, buffer, count, offset, WR_COMPRESS_DATA);
> +}
> +
> +u64 f2fs_write_addrtag(struct f2fs_sb_info *sbi, nid_t ino, pgoff_t offset,
> +		unsigned int addrtag)
> +{
> +	ASSERT(addrtag == COMPRESS_ADDR || addrtag == NEW_ADDR
> +			|| addrtag == NULL_ADDR);
> +	return f2fs_write_ex(sbi, ino, NULL, F2FS_BLKSIZE, offset, addrtag);
> +}
> +
>  /* This function updates only inode->i.i_size */
>  void f2fs_filesize_update(struct f2fs_sb_info *sbi, nid_t ino, u64 filesize)
>  {
> @@ -342,11 +398,59 @@ void f2fs_filesize_update(struct f2fs_sb_info *sbi, nid_t ino, u64 filesize)
>  	free(inode);
>  }
>  
> +#define MAX_BULKR_RETRY 5
> +int bulkread(int fd, void *rbuf, size_t rsize, bool *eof)
> +{
> +	int n = 0;
> +	int retry = MAX_BULKR_RETRY;
> +	int cur;
> +
> +	if (!rsize)
> +		return 0;
> +
> +	if (eof != NULL)
> +		*eof = false;
> +	while (rsize && (cur = read(fd, rbuf, rsize)) != 0) {
> +		if (cur == -1) {
> +			if (errno == EINTR && retry--)
> +				continue;
> +			return -1;
> +		}
> +		retry = MAX_BULKR_RETRY;
> +
> +		rsize -= cur;
> +		n += cur;
> +	}
> +	if (eof != NULL)
> +		*eof = (cur == 0);
> +	return n;
> +}
> +
> +u64 f2fs_fix_mutable(struct f2fs_sb_info *sbi, nid_t ino, pgoff_t offset,
> +		unsigned int compressed)
> +{
> +	unsigned int i;
> +	u64 wlen;
> +
> +	if (c.sldc_immutable)
> +		return 0;
> +
> +	for (i = 0; i < compressed - 1; i++) {
> +		wlen = f2fs_write_addrtag(sbi, ino,
> +				offset + (i << F2FS_BLKSIZE_BITS), NEW_ADDR);
> +		if (wlen)
> +			return wlen;
> +	}
> +	return 0;
> +}
> +
>  int f2fs_build_file(struct f2fs_sb_info *sbi, struct dentry *de)
>  {
>  	int fd, n;
>  	pgoff_t off = 0;
>  	u8 buffer[BLOCK_SZ];
> +	struct node_info ni;
> +	struct f2fs_node *node_blk;
>  
>  	if (de->ino == 0)
>  		return -1;
> @@ -359,8 +463,6 @@ int f2fs_build_file(struct f2fs_sb_info *sbi, struct dentry *de)
>  
>  	/* inline_data support */
>  	if (de->size <= DEF_MAX_INLINE_DATA) {
> -		struct node_info ni;
> -		struct f2fs_node *node_blk;
>  		int ret;
>  
>  		get_node_info(sbi, de->ino, &ni);
> @@ -385,6 +487,82 @@ int f2fs_build_file(struct f2fs_sb_info *sbi, struct dentry *de)
>  		node_blk->i.i_size = cpu_to_le64(de->size);
>  		ASSERT(write_inode(node_blk, ni.blk_addr) >= 0);
>  		free(node_blk);
> +#ifdef WITH_SLOAD
> +	} else if (c.func == SLOAD && c.sldc_en &&
> +			c.sldc_ef->filter(de->full_path)) {
> +		bool eof = false;
> +		u8 *rbuf = c.sldc_cc.rbuf;
> +		unsigned int cblocks = 0;
> +
> +		node_blk = calloc(BLOCK_SZ, 1);
> +		ASSERT(node_blk);
> +
> +		/* read inode */
> +		get_node_info(sbi, de->ino, &ni);
> +		ASSERT(dev_read_block(node_blk, ni.blk_addr) >= 0);
> +		/* update inode meta */
> +		node_blk->i.i_compress_algrithm = c.sldc_ca;
> +		node_blk->i.i_log_cluster_size =
> +				c.sldc_cc.log_cluster_size;
> +		node_blk->i.i_flags = cpu_to_le32(
> +				F2FS_COMPR_FL |
> +				(c.sldc_immutable ? FS_IMMUTABLE_FL : 0));
> +		ASSERT(write_inode(node_blk, ni.blk_addr) >= 0);
> +
> +		while (!eof && (n = bulkread(fd, rbuf, c.sldc_cc.rlen,
> +				&eof)) > 0) {
> +			int ret = c.sldc_compr->compress(&c.sldc_cc);
> +			u64 wlen;
> +			u32 csize = ALIGN_UP(c.sldc_cc.clen +
> +					COMPRESS_HEADER_SIZE, BLOCK_SZ);
> +			unsigned int cur_cblk;
> +
> +			if (ret || n < (int)(csize + BLOCK_SZ *
> +						c.sldc_min_cbpc)) {
> +				wlen = f2fs_write(sbi, de->ino, rbuf, n, off);
> +				ASSERT((int)wlen == n);
> +			} else {
> +				wlen = f2fs_write_addrtag(sbi, de->ino, off,
> +						WR_COMPRESS_ADDR);
> +				ASSERT(!wlen);
> +				wlen = f2fs_write_compress_data(sbi, de->ino,
> +						(u8 *)c.sldc_cc.cbuf,
> +						csize, off + BLOCK_SZ);
> +				ASSERT(wlen == csize);
> +				sldc_erase_bufs(&c.sldc_cc);
> +				cur_cblk = (c.sldc_cc.rlen - csize) / BLOCK_SZ;
> +				cblocks += cur_cblk;
> +				wlen = f2fs_fix_mutable(sbi, de->ino,
> +						off + BLOCK_SZ + csize,
> +						cur_cblk);
> +				ASSERT(!wlen);
> +			}
> +			off += n;
> +		}
> +		if (n == -1) {
> +			fprintf(stderr, "Load file '%s' failed: ",
> +					de->full_path);
> +			perror(NULL);
> +		}
> +		/* read inode */
> +		get_node_info(sbi, de->ino, &ni);
> +		ASSERT(dev_read_block(node_blk, ni.blk_addr) >= 0);
> +		/* update inode meta */
> +		node_blk->i.i_size = cpu_to_le64(off);
> +		if (!c.sldc_immutable)
> +			node_blk->i.i_compr_blocks = cpu_to_le64(cblocks);
> +		ASSERT(write_inode(node_blk, ni.blk_addr) >= 0);
> +		free(node_blk);
> +
> +		if (!c.sldc_immutable) {
> +			sbi->total_valid_block_count += cblocks;
> +			if (sbi->total_valid_block_count >=
> +					sbi->user_block_count) {
> +				ERR_MSG("Not enough space\n");
> +				ASSERT(0);
> +			}
> +		}
> +#endif
>  	} else {
>  		while ((n = read(fd, buffer, BLOCK_SZ)) > 0) {
>  			f2fs_write(sbi, de->ino, buffer, n, off);
> diff --git a/fsck/sload.c b/fsck/sload.c
> index 14012fb..13e523a 100644
> --- a/fsck/sload.c
> +++ b/fsck/sload.c
> @@ -6,6 +6,9 @@
>   *   Hou Pengyang <houpengyang@huawei.com>
>   *   Liu Shuoran <liushuoran@huawei.com>
>   *   Jaegeuk Kim <jaegeuk@kernel.org>
> + * Copyright (c) 2020 Google Inc.
> + *   Robin Hsu <robinhsu@google.com>
> + *  : add sload compression support
>   *
>   * This program is free software; you can redistribute it and/or modify
>   * it under the terms of the GNU General Public License version 2 as
> @@ -317,6 +320,70 @@ skip:
>  	return 0;
>  }
>  
> +typedef struct _ext_tbl {
> +	const char *ext;
> +	struct _ext_tbl *next; /* linked list */
> +} ext_tbl_t;
> +static ext_tbl_t *ext_tbl;
> +
> +static bool ext_found(const char *ext)
> +{
> +	ext_tbl_t *p = ext_tbl;
> +
> +	while (p != NULL && strcmp(ext, p->ext))
> +		p = p->next;
> +	return (p != NULL);
> +}
> +
> +static const char *get_ext(const char *path)
> +{
> +	char *p = strrchr(path, '.');
> +	return p == NULL ? path + strlen(path) : p + 1;
> +}
> +
> +static bool ext_do_filter(const char *path)
> +{
> +	return (ext_found(get_ext(path)) == true) ^ (c.sldc_policy == FP_ALLOW);
> +}
> +
> +static void ext_filter_add(const char *ext)
> +{
> +	ext_tbl_t *node;
> +
> +	ASSERT(ext != NULL);
> +	if (ext_found(ext))
> +		return; /* ext was already registered */
> +	node = malloc(sizeof(ext_tbl_t));
> +	ASSERT(node != NULL);
> +	node->ext = ext;
> +	node->next = ext_tbl;
> +	ext_tbl = node;
> +}
> +
> +static void ext_filter_destroy(void)
> +{
> +	ext_tbl_t *p;
> +
> +	while (ext_tbl != NULL) {
> +		p = ext_tbl;
> +		ext_tbl = p->next;
> +		free(p);
> +	}
> +}
> +
> +struct ext_tbl_op ext_filter = {
> +	.add = ext_filter_add,
> +	.destroy = ext_filter_destroy,
> +	.filter = ext_do_filter,
> +};
> +
> +void sldc_erase_bufs(struct compress_ctx *cc)
> +{
> +	memset(cc->rbuf, 0, cc->cluster_size * F2FS_BLKSIZE);
> +	memset(cc->cbuf->cdata, 0, cc->cluster_size * F2FS_BLKSIZE
> +			- F2FS_BLKSIZE);
> +}
> +
>  int f2fs_sload(struct f2fs_sb_info *sbi)
>  {
>  	int ret = 0;
> diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
> index 1348e39..2a2dc15 100644
> --- a/include/f2fs_fs.h
> +++ b/include/f2fs_fs.h
> @@ -5,6 +5,9 @@
>   *             http://www.samsung.com/
>   * Copyright (c) 2019 Google Inc.
>   *             http://www.google.com/
> + * Copyright (c) 2020 Google Inc.
> + *   Robin Hsu <robinhsu@google.com>
> + *  : add sload compression support
>   *
>   * Dual licensed under the GPL or LGPL version 2 licenses.
>   *
> @@ -68,6 +71,10 @@ typedef uint16_t u_int16_t;
>  typedef uint8_t u_int8_t;
>  #endif
>  
> +/* codes from kernel's f2fs.h, GPL-v2.0 */
> +#define MIN_COMPRESS_LOG_SIZE	2
> +#define MAX_COMPRESS_LOG_SIZE	8
> +
>  typedef u_int64_t	u64;
>  typedef u_int32_t	u32;
>  typedef u_int16_t	u16;
> @@ -93,6 +100,31 @@ typedef u32	__be32;
>  typedef u64	__be64;
>  #endif
>  
> +/*
> + * code borrowed from kernel f2fs dirver: f2fs.h, GPL-2.0
> + *  : definitions of COMPRESS_DATA_RESERVED_SIZE,
> + *    struct compress_data, COMPRESS_HEADER_SIZE,
> + *    and struct compress_ctx
> + */
> +#define COMPRESS_DATA_RESERVED_SIZE		4
> +struct compress_data {
> +	__le32 clen;			/* compressed data size */
> +	__le32 chksum;			/* checksum of compressed data */
> +	__le32 reserved[COMPRESS_DATA_RESERVED_SIZE];	/* reserved */
> +	u8 cdata[];			/* compressed data */
> +};
> +#define COMPRESS_HEADER_SIZE	(sizeof(struct compress_data))
> +/* compress context */
> +struct compress_ctx {
> +	unsigned int cluster_size;	/* page count in cluster */
> +	unsigned int log_cluster_size;	/* log of cluster size */
> +	void *rbuf;			/* compression input buffer */
> +	struct compress_data *cbuf;	/* comprsssion output header + data */
> +	size_t rlen;			/* valid data length in rbuf */
> +	size_t clen;			/* valid data length in cbuf */
> +	void *private;			/* work buf for compress algorithm */
> +};
> +
>  #if HAVE_BYTESWAP_H
>  #include <byteswap.h>
>  #else
> @@ -345,6 +377,25 @@ typedef struct {
>  	bool dbg_en;
>  } dev_cache_config_t;
>  
> +/* f2fs_configration: sldc_ca, the sload compress algorithm */
> +enum {CA_LZO, CA_LZ4};
> +extern const char *ca_names[];
> +
> +typedef struct  {
> +	void (*init)(struct compress_ctx *cc);
> +	int (*compress)(struct compress_ctx *cc);
> +} compress_ops;
> +
> +#define ALIGN_UP(value, size) ((value) + ((value) % (size) > 0 ? \
> +		(size) - (value) % (size) : 0))
> +
> +enum filter_policy {FP_UNASSIGNED = 0, FP_ALLOW, FP_DENY};
> +struct ext_tbl_op {
> +	void (*add)(const char *);
> +	void (*destroy)(void);
> +	bool (*filter)(const char *);
> +};
> +
>  struct f2fs_configuration {
>  	u_int32_t reserved_segments;
>  	u_int32_t new_reserved_segments;
> @@ -441,6 +492,24 @@ struct f2fs_configuration {
>  
>  	/* cache parameters */
>  	dev_cache_config_t cache_config;
> +
> +	/* quick dynamic buffer */
> +	bool qbuf_initialized;
> +	size_t qbufsize;
> +	void *qbuf;
> +
> +	/* sldc: sload compression support */
> +	bool sldc_en;
> +	bool sldc_use_allow_list;  /* default false to use the deny list */
> +	struct compress_ctx sldc_cc;
> +	u8 sldc_ca; /* compress algorithm: 0 = LZO, 1 = LZ4 */
> +	compress_ops *sldc_compr;
> +	enum filter_policy sldc_policy;
> +	/* max_cppc can used to specify minimum compression rate */
> +	unsigned int sldc_min_cbpc; /* min compressed pages per cluster */
> +	bool sldc_got_opt;
> +	bool sldc_immutable;
> +	struct ext_tbl_op *sldc_ef; /* extension filter */
>  };
>  
>  #ifdef CONFIG_64BIT
> @@ -1226,6 +1295,11 @@ extern void f2fs_release_sparse_resource(void);
>  extern int f2fs_finalize_device(void);
>  extern int f2fs_fsync_device(void);
>  
> +/* quick (shared) buffer */
> +extern void qbuf_free(void);
> +extern void *qbuf_alloc(size_t size);
> +extern void qbuf_init(void);
> +
>  extern void dcache_init(void);
>  extern void dcache_release(void);
>  
> @@ -1377,7 +1451,7 @@ int f2fs_reset_zone(int, void *);
>  extern int f2fs_reset_zones(int);
>  extern uint32_t f2fs_get_usable_segments(struct f2fs_super_block *sb);
>  
> -#define SIZE_ALIGN(val, size)	((val) + (size) - 1) / (size)
> +#define SIZE_ALIGN(val, size)	(((val) + (size) - 1) / (size))
>  #define SEG_ALIGN(blks)		SIZE_ALIGN(blks, c.blks_per_seg)
>  #define ZONE_ALIGN(blks)	SIZE_ALIGN(blks, c.blks_per_seg * \
>  					c.segs_per_zone)
> diff --git a/lib/libf2fs_io.c b/lib/libf2fs_io.c
> index 138285d..0280896 100644
> --- a/lib/libf2fs_io.c
> +++ b/lib/libf2fs_io.c
> @@ -5,6 +5,9 @@
>   *             http://www.samsung.com/
>   * Copyright (c) 2019 Google Inc.
>   *             http://www.google.com/
> + * Copyright (c) 2020 Google Inc.
> + *   Robin Hsu <robinhsu@google.com>
> + *  : add quick-buffer for sload compression support
>   *
>   * Dual licensed under the GPL or LGPL version 2 licenses.
>   */
> @@ -106,6 +109,36 @@ static long dcache_relocate_offset0[] = {
>  };
>  static int dcache_relocate_offset[16];
>  
> +/* quick (shared) buffer */
> +static bool qbuf_initialized;
> +static void *qbuf;
> +static size_t qbufsize;
> +void qbuf_free(void)
> +{
> +	ASSERT(qbuf_initialized);
> +	if (qbuf != NULL) {
> +		free(qbuf);
> +		qbuf = NULL;
> +		qbufsize = 0;
> +	}
> +}
> +void *qbuf_alloc(size_t size)
> +{
> +	ASSERT(qbuf_initialized);
> +	if (size > qbufsize) {
> +		qbuf_free();
> +		qbuf = malloc(size);
> +	}
> +	return qbuf;
> +}
> +void qbuf_init(void)
> +{
> +	if (qbuf_initialized)
> +		return;
> +	atexit(qbuf_free);
> +	qbuf_initialized = true;
> +}
> +
>  static void dcache_print_statistics(void)
>  {
>  	long i;
> -- 
> 2.29.2.576.ga3fc446d84-goog