102 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			102 lines
		
	
	
		
			2.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* vi: set sw=4 ts=4: */
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| /*
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|  * ext_attr.c --- extended attribute blocks
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|  *
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|  * Copyright (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
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|  *
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|  * Copyright (C) 2002 Theodore Ts'o.
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|  *
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|  * %Begin-Header%
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|  * This file may be redistributed under the terms of the GNU Public
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|  * License.
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|  * %End-Header%
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|  */
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| 
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| #include <stdio.h>
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| #include <unistd.h>
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| #include <string.h>
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| #include <time.h>
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| 
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| #include "ext2_fs.h"
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| #include "ext2_ext_attr.h"
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| #include "ext2fs.h"
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| 
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| errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf)
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| {
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| 	errcode_t	retval;
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| 
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| 	retval = io_channel_read_blk(fs->io, block, 1, buf);
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| 	if (retval)
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| 		return retval;
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| #if BB_BIG_ENDIAN
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| 	if ((fs->flags & (EXT2_FLAG_SWAP_BYTES|
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| 			  EXT2_FLAG_SWAP_BYTES_READ)) != 0)
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| 		ext2fs_swap_ext_attr(buf, buf, fs->blocksize, 1);
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| #endif
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| 	return 0;
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| }
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| 
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| errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf)
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| {
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| 	errcode_t	retval;
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| 	char		*write_buf;
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| 	char		*buf = NULL;
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| 
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| 	if (BB_BIG_ENDIAN && ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
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| 	    (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))) {
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| 		retval = ext2fs_get_mem(fs->blocksize, &buf);
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| 		if (retval)
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| 			return retval;
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| 		write_buf = buf;
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| 		ext2fs_swap_ext_attr(buf, inbuf, fs->blocksize, 1);
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| 	} else
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| 		write_buf = (char *) inbuf;
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| 	retval = io_channel_write_blk(fs->io, block, 1, write_buf);
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| 	if (buf)
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| 		ext2fs_free_mem(&buf);
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| 	if (!retval)
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| 		ext2fs_mark_changed(fs);
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| 	return retval;
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| }
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| 
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| /*
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|  * This function adjusts the reference count of the EA block.
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|  */
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| errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
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| 				    char *block_buf, int adjust,
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| 				    __u32 *newcount)
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| {
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| 	errcode_t	retval;
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| 	struct ext2_ext_attr_header *header;
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| 	char	*buf = NULL;
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| 
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| 	if ((blk >= fs->super->s_blocks_count) ||
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| 	    (blk < fs->super->s_first_data_block))
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| 		return EXT2_ET_BAD_EA_BLOCK_NUM;
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| 
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| 	if (!block_buf) {
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| 		retval = ext2fs_get_mem(fs->blocksize, &buf);
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| 		if (retval)
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| 			return retval;
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| 		block_buf = buf;
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| 	}
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| 
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| 	retval = ext2fs_read_ext_attr(fs, blk, block_buf);
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| 	if (retval)
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| 		goto errout;
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| 
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| 	header = (struct ext2_ext_attr_header *) block_buf;
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| 	header->h_refcount += adjust;
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| 	if (newcount)
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| 		*newcount = header->h_refcount;
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| 
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| 	retval = ext2fs_write_ext_attr(fs, blk, block_buf);
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| 	if (retval)
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| 		goto errout;
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| 
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| errout:
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| 	if (buf)
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| 		ext2fs_free_mem(&buf);
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| 	return retval;
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| }
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