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/* minix.c - The minix filesystem, version 1 and 2. */
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* GRUB -- GRand Unified Bootloader
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* Copyright (C) 2004,2005,2006,2007,2008 Free Software Foundation, Inc.
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* GRUB is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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* GRUB is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
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#include <grub/file.h>
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#include <grub/misc.h>
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#include <grub/disk.h>
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#include <grub/types.h>
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#define GRUB_MINIX_MAGIC 0x137F
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#define GRUB_MINIX2_MAGIC 0x2468
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#define GRUB_MINIX_MAGIC_30 0x138F
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#define GRUB_MINIX2_MAGIC_30 0x2478
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#define GRUB_MINIX_BSIZE 1024U
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#define GRUB_MINIX_LOG2_BSIZE 1
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#define GRUB_MINIX_ROOT_INODE 1
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#define GRUB_MINIX_MAX_SYMLNK_CNT 8
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#define GRUB_MINIX_SBLOCK 2
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#define GRUB_MINIX_IFDIR 0040000U
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#define GRUB_MINIX_IFLNK 0120000U
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#define GRUB_MINIX_INODE(data,field) (data->version == 1 ? \
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data->inode. field : data->inode2. field)
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#define GRUB_MINIX_INODE_ENDIAN(data,field,bits1,bits2) (data->version == 1 ? \
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grub_le_to_cpu##bits1 (data->inode.field) : \
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grub_le_to_cpu##bits2 (data->inode2.field))
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#define GRUB_MINIX_INODE_SIZE(data) GRUB_MINIX_INODE_ENDIAN (data,size,16,32)
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#define GRUB_MINIX_INODE_MODE(data) GRUB_MINIX_INODE_ENDIAN (data,mode,16,16)
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#define GRUB_MINIX_INODE_DIR_ZONES(data,blk) GRUB_MINIX_INODE_ENDIAN \
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(data,dir_zones[blk],16,32)
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#define GRUB_MINIX_INODE_INDIR_ZONE(data) \
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GRUB_MINIX_INODE_ENDIAN (data,indir_zone,16,32)
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#define GRUB_MINIX_INODE_DINDIR_ZONE(data) \
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GRUB_MINIX_INODE_ENDIAN (data,double_indir_zone,16,32)
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#define GRUB_MINIX_INODE_BLKSZ(data) (data->version == 1 ? 2 : 4)
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#define GRUB_MINIX_LOG2_ZONESZ (GRUB_MINIX_LOG2_BSIZE \
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+ grub_le_to_cpu16 (sblock->log2_zone_size))
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#define GRUB_MINIX_ZONESZ (GRUB_MINIX_BSIZE \
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<< grub_le_to_cpu16 (sblock->log2_zone_size))
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struct grub_minix_sblock
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grub_uint16_t inode_cnt;
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grub_uint16_t zone_cnt;
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grub_uint16_t inode_bmap_size;
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grub_uint16_t zone_bmap_size;
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grub_uint16_t first_data_zone;
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grub_uint16_t log2_zone_size;
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grub_uint32_t max_file_size;
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struct grub_minix_inode
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grub_uint16_t dir_zones[7];
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grub_uint16_t indir_zone;
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grub_uint16_t double_indir_zone;
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struct grub_minix2_inode
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grub_uint32_t dir_zones[7];
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grub_uint32_t indir_zone;
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grub_uint32_t double_indir_zone;
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/* Information about a "mounted" minix filesystem. */
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struct grub_minix_data
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struct grub_minix_sblock sblock;
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struct grub_minix_inode inode;
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struct grub_minix2_inode inode2;
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static grub_dl_t my_mod;
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static grub_err_t grub_minix_find_file (struct grub_minix_data *data,
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grub_minix_get_file_block (struct grub_minix_data *data, unsigned int blk)
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struct grub_minix_sblock *sblock = &data->sblock;
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auto int grub_get_indir (int, int);
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/* Read the block pointer in ZONE, on the offset NUM. */
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int grub_get_indir (int zone, int num)
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if (data->version == 1)
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grub_uint16_t indir16;
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grub_disk_read (data->disk,
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zone << GRUB_MINIX_LOG2_ZONESZ,
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sizeof (grub_uint16_t) * num,
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sizeof (grub_uint16_t), (char *) &indir16);
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return grub_le_to_cpu16 (indir16);
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grub_uint32_t indir32;
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grub_disk_read (data->disk,
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zone << GRUB_MINIX_LOG2_ZONESZ,
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sizeof (grub_uint32_t) * num,
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sizeof (grub_uint32_t), (char *) &indir32);
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return grub_le_to_cpu32 (indir32);
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return GRUB_MINIX_INODE_DIR_ZONES (data, blk);
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/* Indirect block. */
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if (blk < GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data))
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indir = grub_get_indir (GRUB_MINIX_INODE_INDIR_ZONE (data), blk);
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/* Double indirect block. */
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blk -= GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data);
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if (blk < (GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data))
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* (GRUB_MINIX_ZONESZ / GRUB_MINIX_INODE_BLKSZ (data)))
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indir = grub_get_indir (GRUB_MINIX_INODE_DINDIR_ZONE (data),
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blk / GRUB_MINIX_ZONESZ);
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indir = grub_get_indir (indir, blk % GRUB_MINIX_ZONESZ);
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/* This should never happen. */
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grub_error (GRUB_ERR_OUT_OF_RANGE, "file bigger than maximum size");
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/* Read LEN bytes from the file described by DATA starting with byte
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POS. Return the amount of read bytes in READ. */
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grub_minix_read_file (struct grub_minix_data *data,
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void NESTED_FUNC_ATTR (*read_hook) (grub_disk_addr_t sector,
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unsigned offset, unsigned length),
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int pos, grub_disk_addr_t len, char *buf)
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struct grub_minix_sblock *sblock = &data->sblock;
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/* Adjust len so it we can't read past the end of the file. */
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if (len + pos > GRUB_MINIX_INODE_SIZE (data))
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len = GRUB_MINIX_INODE_SIZE (data) - pos;
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blockcnt = (len + pos + GRUB_MINIX_BSIZE - 1) / GRUB_MINIX_BSIZE;
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for (i = pos / GRUB_MINIX_BSIZE; i < blockcnt; i++)
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int blockoff = pos % GRUB_MINIX_BSIZE;
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int blockend = GRUB_MINIX_BSIZE;
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blknr = grub_minix_get_file_block (data, i);
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if (i == blockcnt - 1)
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blockend = (len + pos) % GRUB_MINIX_BSIZE;
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blockend = GRUB_MINIX_BSIZE;
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if (i == (pos / (int) GRUB_MINIX_BSIZE))
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skipfirst = blockoff;
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blockend -= skipfirst;
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data->disk->read_hook = read_hook;
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grub_disk_read (data->disk, blknr << GRUB_MINIX_LOG2_ZONESZ,
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skipfirst, blockend, buf);
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data->disk->read_hook = 0;
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buf += GRUB_MINIX_BSIZE - skipfirst;
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/* Read inode INO from the mounted filesystem described by DATA. This
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inode is used by default now. */
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grub_minix_read_inode (struct grub_minix_data *data, int ino)
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struct grub_minix_sblock *sblock = &data->sblock;
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/* Block in which the inode is stored. */
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/* The first inode in minix is inode 1. */
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block = ((2 + grub_le_to_cpu16 (sblock->inode_bmap_size)
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+ grub_le_to_cpu16 (sblock->zone_bmap_size))
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<< GRUB_MINIX_LOG2_BSIZE);
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if (data->version == 1)
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block += ino / (GRUB_DISK_SECTOR_SIZE / sizeof (struct grub_minix_inode));
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int offs = (ino % (GRUB_DISK_SECTOR_SIZE
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/ sizeof (struct grub_minix_inode))
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* sizeof (struct grub_minix_inode));
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grub_disk_read (data->disk, block, offs,
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sizeof (struct grub_minix_inode), &data->inode);
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block += ino / (GRUB_DISK_SECTOR_SIZE
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/ sizeof (struct grub_minix2_inode));
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% (GRUB_DISK_SECTOR_SIZE / sizeof (struct grub_minix2_inode))
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* sizeof (struct grub_minix2_inode));
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grub_disk_read (data->disk, block, offs,
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sizeof (struct grub_minix2_inode),&data->inode2);
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return GRUB_ERR_NONE;
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/* Lookup the symlink the current inode points to. INO is the inode
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number of the directory the symlink is relative to. */
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grub_minix_lookup_symlink (struct grub_minix_data *data, int ino)
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char symlink[GRUB_MINIX_INODE_SIZE (data) + 1];
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if (++data->linknest > GRUB_MINIX_MAX_SYMLNK_CNT)
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return grub_error (GRUB_ERR_SYMLINK_LOOP, "too deep nesting of symlinks");
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if (grub_minix_read_file (data, 0, 0,
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GRUB_MINIX_INODE_SIZE (data), symlink) < 0)
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symlink[GRUB_MINIX_INODE_SIZE (data)] = '\0';
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/* The symlink is an absolute path, go back to the root inode. */
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if (symlink[0] == '/')
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ino = GRUB_MINIX_ROOT_INODE;
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/* Now load in the old inode. */
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if (grub_minix_read_inode (data, ino))
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grub_minix_find_file (data, symlink);
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grub_error (grub_errno, "cannot follow symlink `%s'", symlink);
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/* Find the file with the pathname PATH on the filesystem described by
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grub_minix_find_file (struct grub_minix_data *data, const char *path)
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char fpath[grub_strlen (path) + 1];
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unsigned int pos = 0;
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grub_strcpy (fpath, path);
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/* Skip the first slash. */
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/* Extract the actual part from the pathname. */
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next = grub_strchr (name, '/');
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char filename[data->filename_size + 1];
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if (grub_strlen (name) == 0)
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return GRUB_ERR_NONE;
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if (grub_minix_read_file (data, 0, pos, sizeof (ino),
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if (grub_minix_read_file (data, 0, pos + sizeof (ino),
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data->filename_size, (char *) filename)< 0)
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filename[data->filename_size] = '\0';
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/* Check if the current direntry matches the current part of the
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if (!grub_strcmp (name, filename))
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grub_minix_read_inode (data, grub_le_to_cpu16 (ino));
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/* Follow the symlink. */
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if ((GRUB_MINIX_INODE_MODE (data)
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& GRUB_MINIX_IFLNK) == GRUB_MINIX_IFLNK)
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grub_minix_lookup_symlink (data, dirino);
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next = grub_strchr (name, '/');
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if ((GRUB_MINIX_INODE_MODE (data)
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& GRUB_MINIX_IFDIR) != GRUB_MINIX_IFDIR)
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return grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
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pos += sizeof (ino) + data->filename_size;
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} while (pos < GRUB_MINIX_INODE_SIZE (data));
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grub_error (GRUB_ERR_FILE_NOT_FOUND, "file not found");
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/* Mount the filesystem on the disk DISK. */
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static struct grub_minix_data *
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grub_minix_mount (grub_disk_t disk)
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struct grub_minix_data *data;
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data = grub_malloc (sizeof (struct grub_minix_data));
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/* Read the superblock. */
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grub_disk_read (disk, GRUB_MINIX_SBLOCK, 0,
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sizeof (struct grub_minix_sblock),&data->sblock);
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if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX_MAGIC)
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data->filename_size = 14;
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else if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX2_MAGIC)
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data->filename_size = 14;
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else if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX_MAGIC_30)
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data->filename_size = 30;
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else if (grub_le_to_cpu16 (data->sblock.magic) == GRUB_MINIX2_MAGIC_30)
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data->filename_size = 30;
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grub_error (GRUB_ERR_BAD_FS, "not a minix filesystem");
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grub_minix_dir (grub_device_t device, const char *path,
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int (*hook) (const char *filename,
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const struct grub_dirhook_info *info))
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struct grub_minix_data *data = 0;
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struct grub_minix_sblock *sblock;
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unsigned int pos = 0;
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data = grub_minix_mount (device->disk);
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grub_minix_read_inode (data, GRUB_MINIX_ROOT_INODE);
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sblock = &data->sblock;
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grub_minix_find_file (data, path);
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if ((GRUB_MINIX_INODE_MODE (data) & GRUB_MINIX_IFDIR) != GRUB_MINIX_IFDIR)
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grub_error (GRUB_ERR_BAD_FILE_TYPE, "not a directory");
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while (pos < GRUB_MINIX_INODE_SIZE (data))
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char filename[data->filename_size + 1];
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int dirino = data->ino;
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struct grub_dirhook_info info;
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grub_memset (&info, 0, sizeof (info));
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if (grub_minix_read_file (data, 0, pos, sizeof (ino),
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if (grub_minix_read_file (data, 0, pos + sizeof (ino),
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(char *) filename) < 0)
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filename[data->filename_size] = '\0';
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/* The filetype is not stored in the dirent. Read the inode to
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find out the filetype. This *REALLY* sucks. */
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grub_minix_read_inode (data, grub_le_to_cpu16 (ino));
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info.dir = ((GRUB_MINIX_INODE_MODE (data)
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& GRUB_MINIX_IFDIR) == GRUB_MINIX_IFDIR);
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if (hook (filename, &info) ? 1 : 0)
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/* Load the old inode back in. */
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grub_minix_read_inode (data, dirino);
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pos += sizeof (ino) + data->filename_size;
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/* Open a file named NAME and initialize FILE. */
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grub_minix_open (struct grub_file *file, const char *name)
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struct grub_minix_data *data;
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data = grub_minix_mount (file->device->disk);
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/* Open the inode op the root directory. */
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grub_minix_read_inode (data, GRUB_MINIX_ROOT_INODE);
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if (!name || name[0] != '/')
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grub_error (GRUB_ERR_BAD_FILENAME, "bad filename");
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/* Traverse the directory tree to the node that should be
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grub_minix_find_file (data, name);
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file->size = GRUB_MINIX_INODE_SIZE (data);
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return GRUB_ERR_NONE;
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grub_minix_read (grub_file_t file, char *buf, grub_size_t len)
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struct grub_minix_data *data =
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(struct grub_minix_data *) file->data;
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return grub_minix_read_file (data, file->read_hook, file->offset, len, buf);
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grub_minix_close (grub_file_t file)
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grub_free (file->data);
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return GRUB_ERR_NONE;
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grub_minix_label (grub_device_t device __attribute ((unused)),
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char **label __attribute ((unused)))
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return GRUB_ERR_NONE;
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static struct grub_fs grub_minix_fs =
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.dir = grub_minix_dir,
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.open = grub_minix_open,
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.read = grub_minix_read,
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.close = grub_minix_close,
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.label = grub_minix_label,
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grub_fs_register (&grub_minix_fs);
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grub_fs_unregister (&grub_minix_fs);