Eric Lee / smarc-uboot

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fs/btrfs/compression.c 2.48 KB
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21a14facb   Marek Behún   fs: btrfs: Add si... 
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  /*
   * BTRFS filesystem implementation for U-Boot
   *
   * 2017 Marek Behun, CZ.NIC, marek.behun@nic.cz
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #include "btrfs.h"
  #include <linux/lzo.h>
  #include <u-boot/zlib.h>
2021f083e   Alberto Sánchez Molero   fs: btrfs: Fix un... 
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  #include <asm/unaligned.h>
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  static u32 decompress_lzo(const u8 *cbuf, u32 clen, u8 *dbuf, u32 dlen)
  {
  	u32 tot_len, in_len, res;
  	size_t out_len;
  	int ret;
  
  	if (clen < 4)
  		return -1;
2021f083e   Alberto Sánchez Molero   fs: btrfs: Fix un... 
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  	tot_len = le32_to_cpu(get_unaligned((u32 *)cbuf));
21a14facb   Marek Behún   fs: btrfs: Add si... 
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  	cbuf += 4;
  	clen -= 4;
  	tot_len -= 4;
  
  	if (tot_len == 0 && dlen)
  		return -1;
  	if (tot_len < 4)
  		return -1;
  
  	res = 0;
  
  	while (tot_len > 4) {
2021f083e   Alberto Sánchez Molero   fs: btrfs: Fix un... 
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  		in_len = le32_to_cpu(get_unaligned((u32 *)cbuf));
21a14facb   Marek Behún   fs: btrfs: Add si... 
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  		cbuf += 4;
  		clen -= 4;
  
  		if (in_len > clen || tot_len < 4 + in_len)
  			return -1;
  
  		tot_len -= 4 + in_len;
  
  		out_len = dlen;
  		ret = lzo1x_decompress_safe(cbuf, in_len, dbuf, &out_len);
  		if (ret != LZO_E_OK)
  			return -1;
  
  		cbuf += in_len;
  		clen -= in_len;
  		dbuf += out_len;
  		dlen -= out_len;
  
  		res += out_len;
  	}
  
  	return res;
  }
  
  /* from zutil.h */
  #define PRESET_DICT 0x20
  
  static u32 decompress_zlib(const u8 *_cbuf, u32 clen, u8 *dbuf, u32 dlen)
  {
  	int wbits = MAX_WBITS, ret = -1;
  	z_stream stream;
  	u8 *cbuf;
  	u32 res;
  
  	memset(&stream, 0, sizeof(stream));
  
  	cbuf = (u8 *) _cbuf;
  
  	stream.total_in = 0;
  
  	stream.next_out = dbuf;
  	stream.avail_out = dlen;
  	stream.total_out = 0;
  
  	/* skip adler32 check if deflate and no dictionary */
  	if (clen > 2 && !(cbuf[1] & PRESET_DICT) &&
  	    ((cbuf[0] & 0x0f) == Z_DEFLATED) &&
  	    !(((cbuf[0] << 8) + cbuf[1]) % 31)) {
  		wbits = -((cbuf[0] >> 4) + 8);
  		cbuf += 2;
  		clen -= 2;
  	}
  
  	if (Z_OK != inflateInit2(&stream, wbits))
  		return -1;
  
  	while (stream.total_in < clen) {
  		stream.next_in = cbuf + stream.total_in;
  		stream.avail_in = min((u32) (clen - stream.total_in),
  				      (u32) btrfs_info.sb.sectorsize);
  
  		ret = inflate(&stream, Z_NO_FLUSH);
  		if (ret != Z_OK)
  			break;
  	}
  
  	res = stream.total_out;
  	inflateEnd(&stream);
  
  	if (ret != Z_STREAM_END)
  		return -1;
  
  	return res;
  }
  
  u32 btrfs_decompress(u8 type, const char *c, u32 clen, char *d, u32 dlen)
  {
  	u32 res;
  	const u8 *cbuf;
  	u8 *dbuf;
  
  	cbuf = (const u8 *) c;
  	dbuf = (u8 *) d;
  
  	switch (type) {
  	case BTRFS_COMPRESS_NONE:
  		res = dlen < clen ? dlen : clen;
  		memcpy(dbuf, cbuf, res);
  		return res;
  	case BTRFS_COMPRESS_ZLIB:
  		return decompress_zlib(cbuf, clen, dbuf, dlen);
  	case BTRFS_COMPRESS_LZO:
  		return decompress_lzo(cbuf, clen, dbuf, dlen);
  	default:
  		printf("%s: Unsupported compression in extent: %i
  ", __func__,
  		       type);
  		return -1;
  	}
  }