| 1 | /*
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| 2 | * ext_attr.c --- extended attribute blocks
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| 3 | *
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| 4 | * Copyright (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
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| 5 | *
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| 6 | * Copyright (C) 2002 Theodore Ts'o.
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| 7 | *
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| 8 | * %Begin-Header%
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| 9 | * This file may be redistributed under the terms of the GNU Public
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| 10 | * License.
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| 11 | * %End-Header%
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| 12 | */
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| 13 |
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| 14 | #include <stdio.h>
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| 15 | #include <unistd.h>
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| 16 | #include <string.h>
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| 17 | #include <time.h>
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| 18 |
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| 19 | #include "ext2_fs.h"
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| 20 | #include "ext2_ext_attr.h"
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| 21 | #include "ext2fs.h"
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| 22 |
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| 23 | errcode_t ext2fs_read_ext_attr(ext2_filsys fs, blk_t block, void *buf)
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| 24 | {
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| 25 | errcode_t retval;
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| 26 |
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| 27 | retval = io_channel_read_blk(fs->io, block, 1, buf);
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| 28 | if (retval)
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| 29 | return retval;
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| 30 | #if BB_BIG_ENDIAN
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| 31 | if ((fs->flags & (EXT2_FLAG_SWAP_BYTES|
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| 32 | EXT2_FLAG_SWAP_BYTES_READ)) != 0)
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| 33 | ext2fs_swap_ext_attr(buf, buf, fs->blocksize, 1);
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| 34 | #endif
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| 35 | return 0;
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| 36 | }
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| 37 |
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| 38 | errcode_t ext2fs_write_ext_attr(ext2_filsys fs, blk_t block, void *inbuf)
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| 39 | {
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| 40 | errcode_t retval;
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| 41 | char *write_buf;
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| 42 | char *buf = NULL;
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| 43 |
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| 44 | if (BB_BIG_ENDIAN && ((fs->flags & EXT2_FLAG_SWAP_BYTES) ||
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| 45 | (fs->flags & EXT2_FLAG_SWAP_BYTES_WRITE))) {
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| 46 | retval = ext2fs_get_mem(fs->blocksize, &buf);
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| 47 | if (retval)
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| 48 | return retval;
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| 49 | write_buf = buf;
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| 50 | ext2fs_swap_ext_attr(buf, inbuf, fs->blocksize, 1);
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| 51 | } else
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| 52 | write_buf = (char *) inbuf;
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| 53 | retval = io_channel_write_blk(fs->io, block, 1, write_buf);
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| 54 | if (buf)
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| 55 | ext2fs_free_mem(&buf);
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| 56 | if (!retval)
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| 57 | ext2fs_mark_changed(fs);
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| 58 | return retval;
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| 59 | }
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| 60 |
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| 61 | /*
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| 62 | * This function adjusts the reference count of the EA block.
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| 63 | */
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| 64 | errcode_t ext2fs_adjust_ea_refcount(ext2_filsys fs, blk_t blk,
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| 65 | char *block_buf, int adjust,
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| 66 | __u32 *newcount)
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| 67 | {
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| 68 | errcode_t retval;
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| 69 | struct ext2_ext_attr_header *header;
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| 70 | char *buf = 0;
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| 71 |
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| 72 | if ((blk >= fs->super->s_blocks_count) ||
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| 73 | (blk < fs->super->s_first_data_block))
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| 74 | return EXT2_ET_BAD_EA_BLOCK_NUM;
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| 75 |
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| 76 | if (!block_buf) {
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| 77 | retval = ext2fs_get_mem(fs->blocksize, &buf);
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| 78 | if (retval)
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| 79 | return retval;
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| 80 | block_buf = buf;
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| 81 | }
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| 82 |
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| 83 | retval = ext2fs_read_ext_attr(fs, blk, block_buf);
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| 84 | if (retval)
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| 85 | goto errout;
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| 86 |
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| 87 | header = (struct ext2_ext_attr_header *) block_buf;
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| 88 | header->h_refcount += adjust;
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| 89 | if (newcount)
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| 90 | *newcount = header->h_refcount;
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| 91 |
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| 92 | retval = ext2fs_write_ext_attr(fs, blk, block_buf);
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| 93 | if (retval)
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| 94 | goto errout;
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| 95 |
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| 96 | errout:
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| 97 | if (buf)
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| 98 | ext2fs_free_mem(&buf);
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| 99 | return retval;
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| 100 | }
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