mirror of https://github.com/vitalif/e2fsprogs
142 lines
3.5 KiB
C
142 lines
3.5 KiB
C
/*
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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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#include <stdio.h>
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#if HAVE_UNISTD_H
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#include <unistd.h>
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#endif
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#include <string.h>
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#include <time.h>
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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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#ifdef EXT2FS_ENABLE_SWAPFS
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void ext2fs_swap_ext_attr(ext2_filsys fs, char *to, char *from)
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{
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struct ext2_ext_attr_header *from_header =
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(struct ext2_ext_attr_header *)from;
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struct ext2_ext_attr_header *to_header =
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(struct ext2_ext_attr_header *)to;
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struct ext2_ext_attr_entry *from_entry, *to_entry;
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char *from_end = (char *)from_header + fs->blocksize;
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int n;
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if (to_header != from_header)
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memcpy(to_header, from_header, fs->blocksize);
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to_header->h_magic = ext2fs_swab32(from_header->h_magic);
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to_header->h_blocks = ext2fs_swab32(from_header->h_blocks);
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to_header->h_refcount = ext2fs_swab32(from_header->h_refcount);
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for (n=0; n<4; n++)
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to_header->h_reserved[n] =
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ext2fs_swab32(from_header->h_reserved[n]);
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from_entry = (struct ext2_ext_attr_entry *)(from_header+1);
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to_entry = (struct ext2_ext_attr_entry *)(to_header+1);
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while ((char *)from_entry < from_end && *(__u32 *)from_entry) {
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to_entry->e_value_offs =
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ext2fs_swab16(from_entry->e_value_offs);
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to_entry->e_value_block =
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ext2fs_swab32(from_entry->e_value_block);
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to_entry->e_value_size =
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ext2fs_swab32(from_entry->e_value_size);
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from_entry = EXT2_EXT_ATTR_NEXT(from_entry);
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to_entry = EXT2_EXT_ATTR_NEXT(to_entry);
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}
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}
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#endif
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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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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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#ifdef EXT2FS_ENABLE_SWAPFS
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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(fs, buf, buf);
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#endif
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return 0;
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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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#ifdef EXT2FS_ENABLE_SWAPFS
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if ((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, (void **) &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(fs, buf, inbuf);
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} else
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#endif
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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((void **) &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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* 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 = 0;
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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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if (!block_buf) {
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retval = ext2fs_get_mem(fs->blocksize, (void **) &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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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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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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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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errout:
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if (buf)
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ext2fs_free_mem((void **) &buf);
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return retval;
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}
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