Decompression errors can arise due to corruption of compressed blocks on flash or in memory. This patch propagates errors detected during decompression back to the block layer. Signed-off-by: David VomLehn <dvomlehn@cisco.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			77 lines
		
	
	
	
		
			1.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			77 lines
		
	
	
	
		
			1.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * uncompress.c
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 *
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 * (C) Copyright 1999 Linus Torvalds
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 *
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 * cramfs interfaces to the uncompression library. There's really just
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 * three entrypoints:
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 *
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 *  - cramfs_uncompress_init() - called to initialize the thing.
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 *  - cramfs_uncompress_exit() - tell me when you're done
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 *  - cramfs_uncompress_block() - uncompress a block.
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 *
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 * NOTE NOTE NOTE! The uncompression is entirely single-threaded. We
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 * only have one stream, and we'll initialize it only once even if it
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 * then is used by multiple filesystems.
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 */
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/vmalloc.h>
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#include <linux/zlib.h>
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#include <linux/cramfs_fs.h>
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static z_stream stream;
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static int initialized;
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/* Returns length of decompressed data. */
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int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen)
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{
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	int err;
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	stream.next_in = src;
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	stream.avail_in = srclen;
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	stream.next_out = dst;
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	stream.avail_out = dstlen;
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	err = zlib_inflateReset(&stream);
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	if (err != Z_OK) {
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		printk("zlib_inflateReset error %d\n", err);
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		zlib_inflateEnd(&stream);
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		zlib_inflateInit(&stream);
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	}
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	err = zlib_inflate(&stream, Z_FINISH);
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	if (err != Z_STREAM_END)
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		goto err;
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	return stream.total_out;
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err:
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	printk("Error %d while decompressing!\n", err);
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	printk("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen);
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	return -EIO;
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}
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int cramfs_uncompress_init(void)
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{
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	if (!initialized++) {
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		stream.workspace = vmalloc(zlib_inflate_workspacesize());
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		if ( !stream.workspace ) {
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			initialized = 0;
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			return -ENOMEM;
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		}
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		stream.next_in = NULL;
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		stream.avail_in = 0;
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		zlib_inflateInit(&stream);
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	}
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	return 0;
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}
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void cramfs_uncompress_exit(void)
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{
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	if (!--initialized) {
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		zlib_inflateEnd(&stream);
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		vfree(stream.workspace);
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	}
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}
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