--- /dev/null
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 1999,2000,2001,2002 Free Software Foundation, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+/* Restrictions:
+ This is MINIX V1 only (yet)
+ Disk creation is like:
+ mkfs.minix -c DEVICE
+*/
+
+#ifdef FSYS_MINIX
+
+#include "shared.h"
+#include "filesys.h"
+
+/* #define DEBUG_MINIX */
+
+/* indirect blocks */
+static int mapblock1, mapblock2, namelen;
+
+/* sizes are always in bytes, BLOCK values are always in DEV_BSIZE (sectors) */
+#define DEV_BSIZE 512
+
+/* include/linux/fs.h */
+#define BLOCK_SIZE_BITS 10
+#define BLOCK_SIZE (1<<BLOCK_SIZE_BITS)
+
+/* made up, defaults to 1 but can be passed via mount_opts */
+#define WHICH_SUPER 1
+/* kind of from fs/ext2/super.c (is OK for minix) */
+#define SBLOCK (WHICH_SUPER * BLOCK_SIZE / DEV_BSIZE) /* = 2 */
+
+/* include/asm-i386/type.h */
+typedef __signed__ char __s8;
+typedef unsigned char __u8;
+typedef __signed__ short __s16;
+typedef unsigned short __u16;
+typedef __signed__ int __s32;
+typedef unsigned int __u32;
+
+/* include/linux/minix_fs.h */
+#define MINIX_ROOT_INO 1
+
+/* Not the same as the bogus LINK_MAX in <linux/limits.h>. Oh well. */
+#define MINIX_LINK_MAX 250
+#define MINIX2_LINK_MAX 65530
+
+#define MINIX_I_MAP_SLOTS 8
+#define MINIX_Z_MAP_SLOTS 64
+#define MINIX_SUPER_MAGIC 0x137F /* original minix fs */
+#define MINIX_SUPER_MAGIC2 0x138F /* minix fs, 30 char names */
+#define MINIX2_SUPER_MAGIC 0x2468 /* minix V2 fs */
+#define MINIX2_SUPER_MAGIC2 0x2478 /* minix V2 fs, 30 char names */
+#define MINIX_VALID_FS 0x0001 /* Clean fs. */
+#define MINIX_ERROR_FS 0x0002 /* fs has errors. */
+
+#define MINIX_INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct minix_inode)))
+#define MINIX2_INODES_PER_BLOCK ((BLOCK_SIZE)/(sizeof (struct minix2_inode)))
+
+#define MINIX_V1 0x0001 /* original minix fs */
+#define MINIX_V2 0x0002 /* minix V2 fs */
+
+/* originally this is :
+#define INODE_VERSION(inode) inode->i_sb->u.minix_sb.s_version
+ here we have */
+#define INODE_VERSION(inode) (SUPERBLOCK->s_version)
+
+/*
+ * This is the original minix inode layout on disk.
+ * Note the 8-bit gid and atime and ctime.
+ */
+struct minix_inode {
+ __u16 i_mode;
+ __u16 i_uid;
+ __u32 i_size;
+ __u32 i_time;
+ __u8 i_gid;
+ __u8 i_nlinks;
+ __u16 i_zone[9];
+};
+
+/*
+ * The new minix inode has all the time entries, as well as
+ * long block numbers and a third indirect block (7+1+1+1
+ * instead of 7+1+1). Also, some previously 8-bit values are
+ * now 16-bit. The inode is now 64 bytes instead of 32.
+ */
+struct minix2_inode {
+ __u16 i_mode;
+ __u16 i_nlinks;
+ __u16 i_uid;
+ __u16 i_gid;
+ __u32 i_size;
+ __u32 i_atime;
+ __u32 i_mtime;
+ __u32 i_ctime;
+ __u32 i_zone[10];
+};
+
+/*
+ * minix super-block data on disk
+ */
+struct minix_super_block {
+ __u16 s_ninodes;
+ __u16 s_nzones;
+ __u16 s_imap_blocks;
+ __u16 s_zmap_blocks;
+ __u16 s_firstdatazone;
+ __u16 s_log_zone_size;
+ __u32 s_max_size;
+ __u16 s_magic;
+ __u16 s_state;
+ __u32 s_zones;
+};
+
+struct minix_dir_entry {
+ __u16 inode;
+ char name[0];
+};
+
+/* made up, these are pointers into FSYS_BUF */
+/* read once, always stays there: */
+#define SUPERBLOCK \
+ ((struct minix_super_block *)(FSYS_BUF))
+#define INODE \
+ ((struct minix_inode *)((char *) SUPERBLOCK + BLOCK_SIZE))
+#define DATABLOCK1 \
+ ((char *)((char *)INODE + sizeof(struct minix_inode)))
+#define DATABLOCK2 \
+ ((char *)((char *)DATABLOCK1 + BLOCK_SIZE))
+
+/* linux/stat.h */
+#define S_IFMT 00170000
+#define S_IFLNK 0120000
+#define S_IFREG 0100000
+#define S_IFDIR 0040000
+#define S_ISLNK(m) (((m) & S_IFMT) == S_IFLNK)
+#define S_ISREG(m) (((m) & S_IFMT) == S_IFREG)
+#define S_ISDIR(m) (((m) & S_IFMT) == S_IFDIR)
+
+#define PATH_MAX 1024 /* include/linux/limits.h */
+#define MAX_LINK_COUNT 5 /* number of symbolic links to follow */
+
+/* check filesystem types and read superblock into memory buffer */
+int
+minix_mount (void)
+{
+ if (((current_drive & 0x80) || current_slice != 0)
+ && ! IS_PC_SLICE_TYPE_MINIX (current_slice)
+ && ! IS_PC_SLICE_TYPE_BSD_WITH_FS (current_slice, FS_OTHER))
+ return 0; /* The partition is not of MINIX type */
+
+ if (part_length < (SBLOCK +
+ (sizeof (struct minix_super_block) / DEV_BSIZE)))
+ return 0; /* The partition is too short */
+
+ if (!devread (SBLOCK, 0, sizeof (struct minix_super_block),
+ (char *) SUPERBLOCK))
+ return 0; /* Cannot read superblock */
+
+ switch (SUPERBLOCK->s_magic)
+ {
+ case MINIX_SUPER_MAGIC:
+ namelen = 14;
+ break;
+ case MINIX_SUPER_MAGIC2:
+ namelen = 30;
+ break;
+ default:
+ return 0; /* Unsupported type */
+ }
+
+ return 1;
+}
+
+/* Takes a file system block number and reads it into BUFFER. */
+static int
+minix_rdfsb (int fsblock, char *buffer)
+{
+ return devread (fsblock * (BLOCK_SIZE / DEV_BSIZE), 0,
+ BLOCK_SIZE, buffer);
+}
+
+/* Maps LOGICAL_BLOCK (the file offset divided by the blocksize) into
+ a physical block (the location in the file system) via an inode. */
+static int
+minix_block_map (int logical_block)
+{
+ int i;
+
+ if (logical_block < 7)
+ return INODE->i_zone[logical_block];
+
+ logical_block -= 7;
+ if (logical_block < 512)
+ {
+ i = INODE->i_zone[7];
+
+ if (!i || ((mapblock1 != 1)
+ && !minix_rdfsb (i, DATABLOCK1)))
+ {
+ errnum = ERR_FSYS_CORRUPT;
+ return -1;
+ }
+ mapblock1 = 1;
+ return ((__u16 *) DATABLOCK1) [logical_block];
+ }
+
+ logical_block -= 512;
+ i = INODE->i_zone[8];
+ if (!i || ((mapblock1 != 2)
+ && !minix_rdfsb (i, DATABLOCK1)))
+ {
+ errnum = ERR_FSYS_CORRUPT;
+ return -1;
+ }
+ mapblock1 = 2;
+ i = ((__u16 *) DATABLOCK1)[logical_block >> 9];
+ if (!i || ((mapblock2 != i)
+ && !minix_rdfsb (i, DATABLOCK2)))
+ {
+ errnum = ERR_FSYS_CORRUPT;
+ return -1;
+ }
+ mapblock2 = i;
+ return ((__u16 *) DATABLOCK2)[logical_block & 511];
+}
+
+/* read from INODE into BUF */
+int
+minix_read (char *buf, int len)
+{
+ int logical_block;
+ int offset;
+ int map;
+ int ret = 0;
+ int size = 0;
+
+ while (len > 0)
+ {
+ /* find the (logical) block component of our location */
+ logical_block = filepos >> BLOCK_SIZE_BITS;
+ offset = filepos & (BLOCK_SIZE - 1);
+ map = minix_block_map (logical_block);
+#ifdef DEBUG_MINIX
+ printf ("map=%d\n", map);
+#endif
+ if (map < 0)
+ break;
+
+ size = BLOCK_SIZE;
+ size -= offset;
+ if (size > len)
+ size = len;
+
+ disk_read_func = disk_read_hook;
+
+ devread (map * (BLOCK_SIZE / DEV_BSIZE),
+ offset, size, buf);
+
+ disk_read_func = NULL;
+
+ buf += size;
+ len -= size;
+ filepos += size;
+ ret += size;
+ }
+
+ if (errnum)
+ ret = 0;
+
+ return ret;
+}
+
+/* preconditions: minix_mount already executed, therefore supblk in buffer
+ known as SUPERBLOCK
+ returns: 0 if error, nonzero iff we were able to find the file successfully
+ postconditions: on a nonzero return, buffer known as INODE contains the
+ inode of the file we were trying to look up
+ side effects: none yet */
+int
+minix_dir (char *dirname)
+{
+ int current_ino = MINIX_ROOT_INO; /* start at the root */
+ int updir_ino = current_ino; /* the parent of the current directory */
+ int ino_blk; /* fs pointer of the inode's info */
+
+ int str_chk = 0; /* used ot hold the results of a string
+ compare */
+
+ struct minix_inode * raw_inode; /* inode info for current_ino */
+
+ char linkbuf[PATH_MAX]; /* buffer for following sym-links */
+ int link_count = 0;
+
+ char * rest;
+ char ch;
+
+ int off; /* offset within block of directory
+ entry */
+ int loc; /* location within a directory */
+ int blk; /* which data blk within dir entry */
+ long map; /* fs pointer of a particular block from
+ dir entry */
+ struct minix_dir_entry * dp; /* pointer to directory entry */
+
+ /* loop invariants:
+ current_ino = inode to lookup
+ dirname = pointer to filename component we are cur looking up within
+ the directory known pointed to by current_ino (if any) */
+
+#ifdef DEBUG_MINIX
+ printf ("\n");
+#endif
+
+ while (1)
+ {
+#ifdef DEBUG_MINIX
+ printf ("inode %d, dirname %s\n", current_ino, dirname);
+#endif
+
+ ino_blk = (2 + SUPERBLOCK->s_imap_blocks + SUPERBLOCK->s_zmap_blocks
+ + (current_ino - 1) / MINIX_INODES_PER_BLOCK);
+ if (! minix_rdfsb (ino_blk, (char *) INODE))
+ return 0;
+
+ /* reset indirect blocks! */
+ mapblock2 = mapblock1 = -1;
+
+ raw_inode = INODE + ((current_ino - 1) % MINIX_INODES_PER_BLOCK);
+
+ /* copy inode to fixed location */
+ memmove ((void *) INODE, (void *) raw_inode,
+ sizeof (struct minix_inode));
+
+ /* If we've got a symbolic link, then chase it. */
+ if (S_ISLNK (INODE->i_mode))
+ {
+ int len;
+
+ if (++link_count > MAX_LINK_COUNT)
+ {
+ errnum = ERR_SYMLINK_LOOP;
+ return 0;
+ }
+#ifdef DEBUG_MINIX
+ printf ("S_ISLNK (%s)\n", dirname);
+#endif
+
+ /* Find out how long our remaining name is. */
+ len = 0;
+ while (dirname[len] && !isspace (dirname[len]))
+ len++;
+
+ /* Get the symlink size. */
+ filemax = (INODE->i_size);
+ if (filemax + len > sizeof (linkbuf) - 2)
+ {
+ errnum = ERR_FILELENGTH;
+ return 0;
+ }
+
+ if (len)
+ {
+ /* Copy the remaining name to the end of the symlink data.
+ Note that DIRNAME and LINKBUF may overlap! */
+ memmove (linkbuf + filemax, dirname, len);
+ }
+ linkbuf[filemax + len] = '\0';
+
+ /* Read the necessary blocks, and reset the file pointer. */
+ len = grub_read (linkbuf, filemax);
+ filepos = 0;
+ if (!len)
+ return 0;
+
+#ifdef DEBUG_MINIX
+ printf ("symlink=%s\n", linkbuf);
+#endif
+
+ dirname = linkbuf;
+ if (*dirname == '/')
+ {
+ /* It's an absolute link, so look it up in root. */
+ current_ino = MINIX_ROOT_INO;
+ updir_ino = current_ino;
+ }
+ else
+ {
+ /* Relative, so look it up in our parent directory. */
+ current_ino = updir_ino;
+ }
+
+ /* Try again using the new name. */
+ continue;
+ }
+
+ /* If end of filename, INODE points to the file's inode */
+ if (!*dirname || isspace (*dirname))
+ {
+ if (!S_ISREG (INODE->i_mode))
+ {
+ errnum = ERR_BAD_FILETYPE;
+ return 0;
+ }
+
+ filemax = (INODE->i_size);
+ return 1;
+ }
+
+ /* else we have to traverse a directory */
+ updir_ino = current_ino;
+
+ /* skip over slashes */
+ while (*dirname == '/')
+ dirname++;
+
+ /* if this isn't a directory of sufficient size to hold our file,
+ abort */
+ if (!(INODE->i_size) || !S_ISDIR (INODE->i_mode))
+ {
+ errnum = ERR_BAD_FILETYPE;
+ return 0;
+ }
+
+ /* skip to next slash or end of filename (space) */
+ for (rest = dirname; (ch = *rest) && !isspace (ch) && ch != '/';
+ rest++);
+
+ /* look through this directory and find the next filename component */
+ /* invariant: rest points to slash after the next filename component */
+ *rest = 0;
+ loc = 0;
+
+ do
+ {
+#ifdef DEBUG_MINIX
+ printf ("dirname=`%s', rest=`%s', loc=%d\n", dirname, rest, loc);
+#endif
+
+ /* if our location/byte offset into the directory exceeds the size,
+ give up */
+ if (loc >= INODE->i_size)
+ {
+ if (print_possibilities < 0)
+ {
+#if 0
+ putchar ('\n');
+#endif
+ }
+ else
+ {
+ errnum = ERR_FILE_NOT_FOUND;
+ *rest = ch;
+ }
+ return (print_possibilities < 0);
+ }
+
+ /* else, find the (logical) block component of our location */
+ blk = loc >> BLOCK_SIZE_BITS;
+
+ /* we know which logical block of the directory entry we are looking
+ for, now we have to translate that to the physical (fs) block on
+ the disk */
+ map = minix_block_map (blk);
+#ifdef DEBUG_MINIX
+ printf ("fs block=%d\n", map);
+#endif
+ mapblock2 = -1;
+ if ((map < 0) || !minix_rdfsb (map, DATABLOCK2))
+ {
+ errnum = ERR_FSYS_CORRUPT;
+ *rest = ch;
+ return 0;
+ }
+ off = loc & (BLOCK_SIZE - 1);
+ dp = (struct minix_dir_entry *) (DATABLOCK2 + off);
+ /* advance loc prematurely to next on-disk directory entry */
+ loc += sizeof (dp->inode) + namelen;
+
+ /* NOTE: minix filenames are NULL terminated if < NAMELEN
+ else exact */
+
+#ifdef DEBUG_MINIX
+ printf ("directory entry ino=%d\n", dp->inode);
+ if (dp->inode)
+ printf ("entry=%s\n", dp->name);
+#endif
+
+ if (dp->inode)
+ {
+ int saved_c = dp->name[namelen];
+
+ dp->name[namelen] = 0;
+ str_chk = substring (dirname, dp->name);
+
+# ifndef STAGE1_5
+ if (print_possibilities && ch != '/'
+ && (!*dirname || str_chk <= 0))
+ {
+ if (print_possibilities > 0)
+ print_possibilities = -print_possibilities;
+ print_a_completion (dp->name);
+ }
+# endif
+
+ dp->name[namelen] = saved_c;
+ }
+
+ }
+ while (!dp->inode || (str_chk || (print_possibilities && ch != '/')));
+
+ current_ino = dp->inode;
+ *(dirname = rest) = ch;
+ }
+ /* never get here */
+}
+
+#endif /* FSYS_MINIX */
Code Review / kvmfornfv.git / blobdiff