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bztsrc--bootboot/mkbootimg/minix.c
bzt 1ac24e3c06 More file system stuff
2021-03-25 08:30:25 +01:00

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/*
* mkbootimg/minix.c
*
* Copyright (C) 2017 - 2021 bzt (bztsrc@gitlab)
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy,
* modify, merge, publish, distribute, sublicense, and/or sell copies
* of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* This file is part of the BOOTBOOT Protocol package.
* @brief Minix3 file system driver
* See https://ohm.hgresser.de/sp-ss2012/Intro-MinixFS.pdf
* (however that's for V2, see the Minix3 source code)
*
*/
#include "main.h"
typedef uint32_t zone_t; /* zone number */
typedef uint32_t block_t; /* block number */
typedef uint32_t bit_t; /* bit number in a bit map */
typedef uint32_t bitchunk_t; /* collection of bits in a bitmap */
#define DEFAULT_BLOCK_SIZE 4096
#define SUPER_V3 0x4d5a /* magic # for V3 file systems */
#define MFS_DIRSIZ 60
#define NR_DZONES 7 /* # direct zone numbers in a V2 inode */
#define NR_TZONES 10 /* total # zone numbers in a V2 inode */
#define NR_DIR_ENTRIES (int)(DEFAULT_BLOCK_SIZE/sizeof(direct_t)) /* # dir entries/blk */
#define INDIRECTS (int)(DEFAULT_BLOCK_SIZE/sizeof(zone_t)) /* # zones/indir block */
#define FS_BITMAP_CHUNKS (int)(DEFAULT_BLOCK_SIZE/sizeof(bitchunk_t)) /*# map chunks/blk*/
#define FS_BITCHUNK_BITS (sizeof(bitchunk_t) * 8)
#define FS_BITS_PER_BLOCK (FS_BITMAP_CHUNKS * FS_BITCHUNK_BITS)
typedef struct {
uint32_t s_ninodes; /* # usable inodes on the minor device */
uint16_t s_nzones; /* total device size, including bit maps etc */
int16_t s_imap_blocks; /* # of blocks used by inode bit map */
int16_t s_zmap_blocks; /* # of blocks used by zone bit map */
uint16_t s_firstdatazone_old; /* number of first data zone (small) */
uint16_t s_log_zone_size; /* log2 of blocks/zone */
uint16_t s_flags; /* FS state flags */
int32_t s_max_size; /* maximum file size on this device */
uint32_t s_zones; /* number of zones (replaces s_nzones in V2) */
int16_t s_magic; /* magic number to recognize super-blocks */
/* The following items are valid on disk only for V3 and above */
int16_t s_pad2; /* try to avoid compiler-dependent padding */
/* The block size in bytes. Minimum MIN_BLOCK SIZE. SECTOR_SIZE multiple.*/
uint16_t s_block_size; /* block size in bytes. */
int8_t s_disk_version; /* filesystem format sub-version */
} __attribute__((packed)) superblock_t;
typedef struct {
uint32_t d_ino;
char d_name[MFS_DIRSIZ];
} __attribute__((packed)) direct_t;
typedef struct { /* V2/V3 disk inode */
uint16_t i_mode; /* file type, protection, etc. */
uint16_t i_nlinks; /* how many links to this file. */
int16_t i_uid; /* user id of the file's owner. */
uint16_t i_gid; /* group number */
uint32_t i_size; /* current file size in bytes */
uint32_t i_atime; /* when was file data last accessed */
uint32_t i_mtime; /* when was file data last changed */
uint32_t i_ctime; /* when was inode data last changed */
uint32_t i_zone[NR_TZONES]; /* zone nums for direct, ind, and dbl ind */
} __attribute__((packed)) inode_t;
block_t mnx_numblk, mnx_inode_offset, mnx_next_zone, mnx_next_inode, mnx_zone_map, mnx_root_inum;
zone_t mnx_zoff;
/* Insert one bit into the bitmap */
void mnx_insert_bit(block_t map, bit_t bit)
{
int boff, w, s;
block_t map_block = map + bit / FS_BITS_PER_BLOCK;
boff = bit % FS_BITS_PER_BLOCK;
w = boff / FS_BITCHUNK_BITS;
s = boff % FS_BITCHUNK_BITS;
*((uint32_t*)(fs_base + map_block * DEFAULT_BLOCK_SIZE + w)) |= (1 << s);
}
/* Increment the link count to inode n */
void mnx_incr_link(ino_t n)
{
inode_t *inodes = (inode_t*)(fs_base + mnx_inode_offset * DEFAULT_BLOCK_SIZE + (n-1) * sizeof(inode_t));
inodes[0].i_nlinks++;
}
/* Increment the file-size in inode n */
void mnx_incr_size(ino_t n, size_t count)
{
inode_t *inodes = (inode_t*)(fs_base + mnx_inode_offset * DEFAULT_BLOCK_SIZE + (n-1) * sizeof(inode_t));
inodes[0].i_size += count;
}
/* allocate an inode */
static ino_t mnx_alloc_inode(int mode, int usrid, int grpid)
{
ino_t num;
inode_t *inodes;
superblock_t *sup = (superblock_t*)(fs_base + 1024);
num = mnx_next_inode++;
if(num > sup->s_ninodes) {
fprintf(stderr,"mkbootimg: partition #%d %s\r\n", fs_no, lang[ERR_TOOMANY]);
exit(1);
}
inodes = (inode_t*)(fs_base + mnx_inode_offset * DEFAULT_BLOCK_SIZE + (num-1) * sizeof(inode_t));
inodes[0].i_mode = mode;
inodes[0].i_uid = usrid;
inodes[0].i_gid = grpid;
/* Set the bit in the bit map. */
mnx_insert_bit((block_t)2, num);
return(num);
}
/* Allocate a new zone */
static zone_t mnx_alloc_zone(void)
{
zone_t z = mnx_next_zone++;
mnx_insert_bit(mnx_zone_map, z - mnx_zoff);
return z;
}
void mnx_add_zone(ino_t n, zone_t z, size_t bytes, time_t mtime, char *name)
{
/* Add zone z to inode n. The file has grown by 'bytes' bytes. */
int i, j;
inode_t *p;
zone_t indir, dindir, *blk, *dblk;
p = (inode_t*)(fs_base + mnx_inode_offset * DEFAULT_BLOCK_SIZE + (n-1) * sizeof(inode_t));
p->i_size += bytes;
p->i_mtime = mtime;
for (i = 0; i < NR_DZONES; i++)
if (p->i_zone[i] == 0) {
p->i_zone[i] = z;
return;
}
/* File has grown beyond a small file. */
if (p->i_zone[NR_DZONES] == 0)
p->i_zone[NR_DZONES] = mnx_alloc_zone();
indir = p->i_zone[NR_DZONES];
--indir; /* Compensate for ++indir below */
for (i = 0; i < INDIRECTS; i++) {
if (i % INDIRECTS == 0)
blk = (zone_t*)(fs_base + ++indir * DEFAULT_BLOCK_SIZE);
if (blk[i % INDIRECTS] == 0) {
blk[i] = z;
return;
}
}
/* File has grown beyond single indirect; we need a double indirect */
if (p->i_zone[NR_DZONES+1] == 0)
p->i_zone[NR_DZONES+1] = mnx_alloc_zone();
dindir = p->i_zone[NR_DZONES+1];
--dindir; /* Compensate for ++indir below */
for (j = 0; j < INDIRECTS; j++) {
if (j % INDIRECTS == 0)
dblk = (zone_t*)(fs_base + ++dindir * DEFAULT_BLOCK_SIZE);
if (dblk[j % INDIRECTS] == 0)
dblk[j % INDIRECTS] = mnx_alloc_zone();
indir = dblk[j % INDIRECTS];
--indir; /* Compensate for ++indir below */
for (i = 0; i < INDIRECTS; i++) {
if (i % INDIRECTS == 0)
blk = (zone_t*)(fs_base + ++indir * DEFAULT_BLOCK_SIZE);
if (blk[i % INDIRECTS] == 0) {
blk[i] = z;
return;
}
}
}
fprintf(stderr,"mkbootimg: partition #%d %s: %s\r\n", fs_no, lang[ERR_TOOBIG], name);
exit(1);
}
int mnx_dir_try_enter(zone_t z, ino_t child, char const *name)
{
direct_t *dir_entry;
int i;
dir_entry = (direct_t*)(fs_base + z * DEFAULT_BLOCK_SIZE);
for (i = 0; i < NR_DIR_ENTRIES; i++)
if (!dir_entry[i].d_ino)
break;
if(i < NR_DIR_ENTRIES) {
dir_entry[i].d_ino = child;
strncpy(dir_entry[i].d_name, name, MFS_DIRSIZ);
return 1;
}
return 0;
}
void mnx_enter_dir(ino_t parent, char const *name, ino_t child)
{
/* Enter child in parent directory */
/* Works for dir > 1 block and zone > block */
unsigned int k;
block_t indir;
zone_t z;
inode_t *ino;
zone_t *indirblock;
/* Obtain the inode structure */
ino = (inode_t*)(fs_base + mnx_inode_offset * DEFAULT_BLOCK_SIZE + (parent-1) * sizeof(inode_t));
for (k = 0; k < NR_DZONES; k++) {
z = ino->i_zone[k];
if (z == 0) {
z = mnx_alloc_zone();
ino->i_zone[k] = z;
}
if(mnx_dir_try_enter(z, child, name))
return;
}
/* no space in directory using just direct blocks; try indirect */
if (ino->i_zone[NR_DZONES] == 0)
ino->i_zone[NR_DZONES] = mnx_alloc_zone();
indir = ino->i_zone[NR_DZONES];
--indir; /* Compensate for ++indir below */
for(k = 0; k < INDIRECTS; k++) {
if (k % INDIRECTS == 0)
indirblock = (zone_t*)(fs_base + ++indir * DEFAULT_BLOCK_SIZE);
z = indirblock[k % INDIRECTS];
if(!z)
z = indirblock[k % INDIRECTS] = mnx_alloc_zone();
if(mnx_dir_try_enter(z, child, name))
return;
}
fprintf(stderr,"mkbootimg: partition #%d %s: %s\r\n", fs_no, lang[ERR_TOOBIG], name);
exit(1);
}
/*** mkbootimg interface ***/
void mnx_open(gpt_t *gpt_entry)
{
zone_t z;
superblock_t *sup;
int i, kb;
if(!gpt_entry) { fprintf(stderr,"mkbootimg: %s minix.\r\n", lang[ERR_BADINITRDTYPE]); exit(1); }
mnx_numblk = (gpt_entry->last - gpt_entry->start + 1) * 512 / DEFAULT_BLOCK_SIZE;
if(mnx_numblk < 8) { fprintf(stderr,"mkbootimg: partition #%d %s\r\n", fs_no, lang[ERR_NOSIZE]); exit(1); }
/* "format" the partition to Minix3FS */
fs_len = mnx_numblk * DEFAULT_BLOCK_SIZE;
fs_base = realloc(fs_base, fs_len);
if(!fs_base) { fprintf(stderr,"mkbootimg: %s\r\n",lang[ERR_MEM]); exit(1); }
memset(fs_base, 0, fs_len);
sup = (superblock_t*)(fs_base + 1024);
kb = fs_len / 1024;
sup->s_ninodes = kb / 2;
if (kb >= 100000) sup->s_ninodes = kb / 4;
if (kb >= 1000000) sup->s_ninodes = kb / 6;
if (kb >= 10000000) sup->s_ninodes = kb / 8;
if (kb >= 100000000) sup->s_ninodes = kb / 10;
if (kb >= 1000000000) sup->s_ninodes = kb / 12;
sup->s_ninodes += (DEFAULT_BLOCK_SIZE/sizeof(inode_t)) - 1;
sup->s_ninodes &= ~((DEFAULT_BLOCK_SIZE/sizeof(inode_t)) - 1);
if(sup->s_ninodes < 1) { fprintf(stderr,"mkbootimg: partition #%d %s\r\n", fs_no, lang[ERR_NOSIZE]); exit(1); }
sup->s_zones = mnx_numblk;
sup->s_imap_blocks = (1 + sup->s_ninodes + DEFAULT_BLOCK_SIZE - 1) / DEFAULT_BLOCK_SIZE;
sup->s_zmap_blocks = (mnx_numblk + DEFAULT_BLOCK_SIZE - 1) / DEFAULT_BLOCK_SIZE;
mnx_inode_offset = 2 + sup->s_imap_blocks + sup->s_zmap_blocks;
sup->s_magic = SUPER_V3;
sup->s_block_size = DEFAULT_BLOCK_SIZE;
i = NR_DZONES+(DEFAULT_BLOCK_SIZE/sizeof(inode_t))+(DEFAULT_BLOCK_SIZE/sizeof(inode_t))*(DEFAULT_BLOCK_SIZE/sizeof(inode_t));
if(INT32_MAX/DEFAULT_BLOCK_SIZE < i)
sup->s_max_size = INT32_MAX;
else
sup->s_max_size = i * DEFAULT_BLOCK_SIZE;
mnx_next_zone = mnx_inode_offset + (sup->s_ninodes+(DEFAULT_BLOCK_SIZE/sizeof(inode_t))-1)/(DEFAULT_BLOCK_SIZE/sizeof(inode_t));
mnx_zoff = mnx_next_zone - 1;
mnx_next_inode = 1;
mnx_zone_map = 2 + sup->s_imap_blocks;
mnx_insert_bit(mnx_zone_map, 0); /* bit zero must always be allocated */
mnx_insert_bit((block_t)2, 0); /* inode zero not used but must be allocated */
mnx_root_inum = mnx_alloc_inode(0755, 0, 0);
z = mnx_alloc_zone();
mnx_add_zone(mnx_root_inum, z, 2 * sizeof(direct_t), t, "rootdir");
mnx_enter_dir(mnx_root_inum, ".", mnx_root_inum);
mnx_enter_dir(mnx_root_inum, "..", mnx_root_inum);
mnx_incr_link(mnx_root_inum);
mnx_incr_link(mnx_root_inum);
}
void mnx_add(struct stat *st, char *name, unsigned char *content, int size)
{
ino_t n, parent = mnx_root_inum;
inode_t *ino;
zone_t z;
direct_t *dir_entry;
int i, k;
char *end, *fn = strrchr(name, '/');
if(!fn) fn = name; else fn++;
if(!strcmp(fn, ".") || !strcmp(fn, "..")) return;
if(!S_ISREG(st->st_mode) && !S_ISDIR(st->st_mode) && !S_ISLNK(st->st_mode) && !S_ISCHR(st->st_mode) && !S_ISBLK(st->st_mode))
return;
n = mnx_alloc_inode(st->st_mode, st->st_uid, st->st_gid);
/* Enter name in directory and update directory's size. */
fn = name;
end = strchr(name, '/');
if(!end) end = name + strlen(name);
i = k = 0;
do {
/* FIXME: this doesn't handle indirect and double indirect data */
ino = (inode_t*)(fs_base + mnx_inode_offset * DEFAULT_BLOCK_SIZE + (parent-1) * sizeof(inode_t));
if(!ino->i_zone[k]) break;
if(k >= NR_DZONES) {
fprintf(stderr,"mkbootimg: partition #%d %s: %s\r\n", fs_no, lang[ERR_TOOBIG], name);
exit(1);
}
dir_entry = (direct_t*)(fs_base + ino->i_zone[k] * DEFAULT_BLOCK_SIZE);
if(!memcmp(dir_entry[i].d_name, fn, end - fn) && !dir_entry[i].d_name[end - fn]) {
parent = dir_entry[i].d_ino; i = k = 0;
fn = end + 1;
end = *end ? strchr(fn, '/') : NULL;
if(!end) break;
}
i++;
if(i == NR_DIR_ENTRIES) { i = 0; k++; }
if((k * NR_DIR_ENTRIES + i) * sizeof(direct_t) >= ino->i_size) break;
} while(1);
mnx_enter_dir(parent, fn, n);
mnx_incr_size(parent, sizeof(direct_t));
/* Check to see if file is directory or special. */
mnx_incr_link(n);
if (S_ISDIR(st->st_mode)) {
/* This is a directory. */
z = mnx_alloc_zone(); /* zone for new directory */
mnx_add_zone(n, z, 2 * sizeof(direct_t), st->st_mtime, name);
mnx_enter_dir(n, ".", n);
mnx_enter_dir(n, "..", parent);
mnx_incr_link(parent);
mnx_incr_link(n);
} else if (S_ISCHR(st->st_mode) || S_ISBLK(st->st_mode)) {
/* Special file. */
mnx_add_zone(n, (zone_t)st->st_rdev, st->st_size, st->st_mtime, name);
} else if (S_ISLNK(st->st_mode)) {
if(size > DEFAULT_BLOCK_SIZE - 1) {
fprintf(stderr,"mkbootimg: partition #%d %s: %s\r\n", fs_no, lang[ERR_TOOBIG], name);
exit(1);
}
z = mnx_alloc_zone();
memcpy(fs_base + z * DEFAULT_BLOCK_SIZE, content, size + 1);
mnx_add_zone(n, z, size, st->st_mtime, name);
} else {
/* Regular file. Go read it. */
while(size) {
z = mnx_alloc_zone();
memcpy(fs_base + z * DEFAULT_BLOCK_SIZE, content, DEFAULT_BLOCK_SIZE);
mnx_add_zone(n, z, size < DEFAULT_BLOCK_SIZE ? size : DEFAULT_BLOCK_SIZE, st->st_mtime, name);
if(size > DEFAULT_BLOCK_SIZE) {
content += DEFAULT_BLOCK_SIZE;
size -= DEFAULT_BLOCK_SIZE;
} else
break;
}
}
}
void mnx_close()
{
}
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