[PATCH/RFC] minix filesystem update to V3 for 2.4 kernels

From: Daniel Aragonés
Date: Wed Jan 25 2006 - 14:00:35 EST


Hi Marcelo,

After 2 revisions incorporating the suggestions made by Pekka, here I attach as a text file "v3_2dot4_diff.txt" my patch for minix-fs version 3 support.

I first posted it in comp.os.minix in January 11. I have no received feedback at all. Can we trust the saying "no news, good news"?...

I have sent the same patch for 2.6 kernels to Andrew today. The present one is a port or adaptation of the 2.6 one, which was the first that I started, to the 2.4 peculiarities.

The modifications I have made to the preexistent code have been four:

1.- The layout of the superblock variables is different in version V3. Suggested by Pekka, the structure minix3_super_block has been introduced.

2.- Disable writings to "s_state" because it has been droped out from the superblock, and its former address is now used by another parameter.

3.- Change the references to the constant "BLOCK_SIZE" to the variables "s_blocksize" or "b_size", so allowing for multiple block sizes.

4.- Introduce the new structure "minix3_dir_entry" to employ 60 characters long names in the new directory entries of 64 bytes.

Signed-off-by: Daniel Aragones <danarag@xxxxxxxxx>







diff -ur orig.linux-2.4.32/fs/minix/bitmap.c updated.linux-2.4.32/fs/minix/bitmap.c
--- orig.linux-2.4.32/fs/minix/bitmap.c 2002-02-25 20:38:09.000000000 +0100
+++ updated.linux-2.4.32/fs/minix/bitmap.c 2006-01-25 16:07:08.000000000 +0100
@@ -27,14 +27,14 @@
for (i=0; i<numblocks-1; i++) {
if (!(bh=map[i]))
return(0);
- for (j=0; j<BLOCK_SIZE; j++)
+ for (j=0; j<bh->b_size; j++)
sum += nibblemap[bh->b_data[j] & 0xf]
+ nibblemap[(bh->b_data[j]>>4) & 0xf];
}

if (numblocks==0 || !(bh=map[numblocks-1]))
return(0);
- i = ((numbits-(numblocks-1)*BLOCK_SIZE*8)/16)*2;
+ i = ((numbits-(numblocks-1)*bh->b_size*8)/16)*2;
for (j=0; j<i; j++) {
sum += nibblemap[bh->b_data[j] & 0xf]
+ nibblemap[(bh->b_data[j]>>4) & 0xf];
@@ -124,6 +124,7 @@
int block;
struct minix_sb_info *sbi = &sb->u.minix_sb;
struct minix_inode *p;
+ int minix_inodes_per_block = BLOCK_SIZE/sizeof(struct minix_inode);

if (!ino || ino > sbi->s_ninodes) {
printk("Bad inode number on dev %s: %ld is out of range\n",
@@ -132,14 +133,14 @@
}
ino--;
block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
- ino / MINIX_INODES_PER_BLOCK;
+ ino / minix_inodes_per_block;
*bh = sb_bread(sb, block);
if (!*bh) {
printk("unable to read i-node block\n");
return NULL;
}
p = (void *)(*bh)->b_data;
- return p + ino % MINIX_INODES_PER_BLOCK;
+ return p + ino % minix_inodes_per_block;
}

struct minix2_inode *
@@ -148,6 +149,7 @@
int block;
struct minix_sb_info *sbi = &sb->u.minix_sb;
struct minix2_inode *p;
+ int minix2_inodes_per_block = sb->s_blocksize/sizeof(struct minix2_inode);

*bh = NULL;
if (!ino || ino > sbi->s_ninodes) {
@@ -157,14 +159,14 @@
}
ino--;
block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
- ino / MINIX2_INODES_PER_BLOCK;
+ ino / minix2_inodes_per_block;
*bh = sb_bread(sb, block);
if (!*bh) {
printk("unable to read i-node block\n");
return NULL;
}
p = (void *)(*bh)->b_data;
- return p + ino % MINIX2_INODES_PER_BLOCK;
+ return p + ino % minix2_inodes_per_block;
}

/* Clear the link count and mode of a deleted inode on disk. */
diff -ur orig.linux-2.4.32/fs/minix/dir.c updated.linux-2.4.32/fs/minix/dir.c
--- orig.linux-2.4.32/fs/minix/dir.c 2002-02-25 20:38:09.000000000 +0100
+++ updated.linux-2.4.32/fs/minix/dir.c 2006-01-25 16:07:08.000000000 +0100
@@ -4,6 +4,9 @@
* Copyright (C) 1991, 1992 Linus Torvalds
*
* minix directory handling functions
+ *
+ * Updated to filesystem version 3 by Daniel Aragones
+ *
*/

#include <linux/fs.h>
@@ -11,6 +14,7 @@
#include <linux/pagemap.h>

typedef struct minix_dir_entry minix_dirent;
+typedef struct minix3_dir_entry minix3_dirent;

static int minix_readdir(struct file *, void *, filldir_t);

@@ -80,6 +84,8 @@
struct minix_sb_info *sbi = &sb->u.minix_sb;
unsigned chunk_size = sbi->s_dirsize;

+ char *namx;
+ __u32 inodx;
pos = (pos + chunk_size-1) & ~(chunk_size-1);
if (pos >= inode->i_size)
goto done;
@@ -95,14 +101,22 @@
limit = kaddr + PAGE_CACHE_SIZE - chunk_size;
for ( ; p <= limit ; p = minix_next_entry(p, sbi)) {
minix_dirent *de = (minix_dirent *)p;
- if (de->inode) {
+ minix3_dirent *de3 = (minix3_dirent *)p;
+ if (sbi->s_version == MINIX_V3) {
+ namx = de3->name;
+ inodx = de3->inode;
+ } else {
+ namx = de->name;
+ inodx = de->inode;
+ }
+ if (inodx) {
int over;
- unsigned l = strnlen(de->name,sbi->s_namelen);

+ unsigned l = strnlen(namx,sbi->s_namelen);
offset = p - kaddr;
- over = filldir(dirent, de->name, l,
- (n<<PAGE_CACHE_SHIFT) | offset,
- de->inode, DT_UNKNOWN);
+ over = filldir(dirent, namx, l,
+ (n<<PAGE_CACHE_SHIFT) | offset,
+ inodx, DT_UNKNOWN);
if (over) {
dir_put_page(page);
goto done;
@@ -145,8 +159,11 @@
unsigned long npages = dir_pages(dir);
struct page *page = NULL;
struct minix_dir_entry *de;
+ struct minix3_dir_entry *de3;

*res_page = NULL;
+ char *namx;
+ __u32 inodx;

for (n = 0; n < npages; n++) {
char *kaddr;
@@ -156,11 +173,21 @@

kaddr = (char*)page_address(page);
de = (struct minix_dir_entry *) kaddr;
+ de3 = (struct minix3_dir_entry *) kaddr;
kaddr += PAGE_CACHE_SIZE - sbi->s_dirsize;
- for ( ; (char *) de <= kaddr ; de = minix_next_entry(de,sbi)) {
- if (!de->inode)
+ for ( ; (char *) de <= kaddr ;
+ de = minix_next_entry(de,sbi),
+ de3 = minix_next_entry(de3,sbi)) {
+ if (sbi->s_version == MINIX_V3) {
+ namx = de3->name;
+ inodx = de3->inode;
+ } else {
+ namx = de->name;
+ inodx = de->inode;
+ }
+ if (!inodx)
continue;
- if (namecompare(namelen,sbi->s_namelen,name,de->name))
+ if (namecompare(namelen,sbi->s_namelen,name,namx))
goto found;
}
dir_put_page(page);
@@ -181,11 +208,14 @@
struct minix_sb_info * sbi = &sb->u.minix_sb;
struct page *page = NULL;
struct minix_dir_entry * de;
+ struct minix3_dir_entry * de3;
unsigned long npages = dir_pages(dir);
unsigned long n;
char *kaddr;
unsigned from, to;
int err;
+ char *namx = NULL;
+ __u32 inodx;

/* We take care of directory expansion in the same loop */
for (n = 0; n <= npages; n++) {
@@ -195,13 +225,22 @@
goto out;
kaddr = (char*)page_address(page);
de = (minix_dirent *)kaddr;
+ de3 = (minix3_dirent *)kaddr;
kaddr += PAGE_CACHE_SIZE - sbi->s_dirsize;
while ((char *)de <= kaddr) {
- if (!de->inode)
+ if (sbi->s_version == MINIX_V3) {
+ namx = de3->name;
+ inodx = de3->inode;
+ } else {
+ namx = de->name;
+ inodx = de->inode;
+ }
+ if (!inodx)
goto got_it;
err = -EEXIST;
- if (namecompare(namelen,sbi->s_namelen,name,de->name))
+ if (namecompare(namelen,sbi->s_namelen,name,namx))
goto out_page;
+ de3 = minix_next_entry(de3, sbi);
de = minix_next_entry(de, sbi);
}
dir_put_page(page);
@@ -216,9 +255,14 @@
err = page->mapping->a_ops->prepare_write(NULL, page, from, to);
if (err)
goto out_unlock;
- memcpy (de->name, name, namelen);
- memset (de->name + namelen, 0, sbi->s_dirsize - namelen - 2);
- de->inode = inode->i_ino;
+ memcpy (namx, name, namelen);
+ if (sbi->s_version == MINIX_V3) {
+ memset (namx + namelen, 0, sbi->s_dirsize - namelen - 4);
+ de3->inode = inode->i_ino;
+ } else {
+ memset (namx + namelen, 0, sbi->s_dirsize - namelen - 2);
+ de->inode = inode->i_ino;
+ }
err = dir_commit_chunk(page, from, to);
dir->i_mtime = dir->i_ctime = CURRENT_TIME;
mark_inode_dirty(dir);
@@ -258,6 +302,7 @@
struct page *page = grab_cache_page(mapping, 0);
struct minix_sb_info * sbi = &inode->i_sb->u.minix_sb;
struct minix_dir_entry * de;
+ struct minix3_dir_entry * de3;
char *base;
int err;

@@ -270,12 +315,22 @@
base = (char*)page_address(page);
memset(base, 0, PAGE_CACHE_SIZE);

- de = (struct minix_dir_entry *) base;
+ de = (struct minix_dir_entry *)base;
+ de3 = (struct minix3_dir_entry *)base;
de->inode = inode->i_ino;
- strcpy(de->name,".");
+ de3->inode = inode->i_ino;
+ if (sbi->s_version == MINIX_V3)
+ strcpy(de3->name,".");
+ else
+ strcpy(de->name,".");
de = minix_next_entry(de, sbi);
+ de3 = minix_next_entry(de3, sbi);
de->inode = dir->i_ino;
- strcpy(de->name,"..");
+ de3->inode = dir->i_ino;
+ if (sbi->s_version == MINIX_V3)
+ strcpy(de3->name,"..");
+ else
+ strcpy(de->name,"..");

err = dir_commit_chunk(page, 0, 2 * sbi->s_dirsize);
fail:
@@ -292,30 +347,42 @@
struct page *page = NULL;
unsigned long i, npages = dir_pages(inode);
struct minix_sb_info *sbi = &inode->i_sb->u.minix_sb;
+ char *namx;
+ __u32 inodx;

for (i = 0; i < npages; i++) {
char *kaddr;
minix_dirent * de;
+ minix3_dirent * de3 = NULL;
page = dir_get_page(inode, i);

if (IS_ERR(page))
continue;

kaddr = (char *)page_address(page);
+ if (sbi->s_version == MINIX_V3)
+ de3 = (minix3_dirent *)kaddr;
de = (minix_dirent *)kaddr;
kaddr += PAGE_CACHE_SIZE - sbi->s_dirsize;

+ if (sbi->s_version == MINIX_V3) {
+ namx = de3->name;
+ inodx = de3->inode;
+ } else {
+ namx = de->name;
+ inodx = de->inode;
+ }
while ((char *)de <= kaddr) {
- if (de->inode != 0) {
+ if (inodx != 0) {
/* check for . and .. */
- if (de->name[0] != '.')
+ if (namx[0] != '.')
goto not_empty;
- if (!de->name[1]) {
- if (de->inode != inode->i_ino)
+ if (!namx[1]) {
+ if (inodx != inode->i_ino)
goto not_empty;
- } else if (de->name[1] != '.')
+ } else if (namx[1] != '.')
goto not_empty;
- else if (de->name[2])
+ else if (namx[2])
goto not_empty;
}
de = minix_next_entry(de, sbi);
diff -ur orig.linux-2.4.32/fs/minix/inode.c updated.linux-2.4.32/fs/minix/inode.c
--- orig.linux-2.4.32/fs/minix/inode.c 2003-11-28 19:26:21.000000000 +0100
+++ updated.linux-2.4.32/fs/minix/inode.c 2006-01-25 16:07:08.000000000 +0100
@@ -7,6 +7,7 @@
* Minix V2 fs support.
*
* Modified for 680x0 by Andreas Schwab
+ * Updated to filesystem version 3 by Daniel Aragones
*/

#include <linux/module.h>
@@ -29,6 +30,7 @@
{
lock_kernel();

+ truncate_inode_pages(&inode->i_data, 0);
inode->i_size = 0;
minix_truncate(inode);
minix_free_inode(inode);
@@ -45,13 +47,16 @@
static void minix_write_super(struct super_block * sb)
{
struct minix_super_block * ms;
+ struct minix_sb_info *sbi = &sb->u.minix_sb;

if (!(sb->s_flags & MS_RDONLY)) {
ms = sb->u.minix_sb.s_ms;

- if (ms->s_state & MINIX_VALID_FS)
- ms->s_state &= ~MINIX_VALID_FS;
- minix_commit_super(sb);
+ if (sbi->s_version != MINIX_V3) { /* s_state is out from V3 sb */
+ if (ms->s_state & MINIX_VALID_FS)
+ ms->s_state &= ~MINIX_VALID_FS;
+ minix_commit_super(sb);
+ }
}
sb->s_dirt = 0;
}
@@ -61,7 +66,8 @@
{
int i;

- if (!(sb->s_flags & MS_RDONLY)) {
+ struct minix_sb_info *sbi = &sb->u.minix_sb;
+ if (!(sb->s_flags & MS_RDONLY) && (sbi->s_version != MINIX_V3)) {
sb->u.minix_sb.s_ms->s_state = sb->u.minix_sb.s_mount_state;
mark_buffer_dirty(sb->u.minix_sb.s_sbh);
}
@@ -88,11 +94,12 @@
static int minix_remount (struct super_block * sb, int * flags, char * data)
{
struct minix_super_block * ms;
+ struct minix_sb_info *sbi = &sb->u.minix_sb;

ms = sb->u.minix_sb.s_ms;
if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY))
return 0;
- if (*flags & MS_RDONLY) {
+ if ((*flags & MS_RDONLY) && (sbi->s_version != MINIX_V3)){
if (ms->s_state & MINIX_VALID_FS ||
!(sb->u.minix_sb.s_mount_state & MINIX_VALID_FS))
return 0;
@@ -102,20 +109,21 @@
sb->s_dirt = 1;
minix_commit_super(sb);
}
- else {
+ else if (sbi->s_version != MINIX_V3){
/* Mount a partition which is read-only, read-write. */
sb->u.minix_sb.s_mount_state = ms->s_state;
ms->s_state &= ~MINIX_VALID_FS;
mark_buffer_dirty(sb->u.minix_sb.s_sbh);
sb->s_dirt = 1;
+ }
+
+ if (!(sb->u.minix_sb.s_mount_state & MINIX_VALID_FS) && (sbi->s_version != MINIX_V3))
+ printk ("MINIX-fs warning: remounting unchecked Minix filesystem V%i, "
+ "running fsck is recommended.\n", sbi->s_version);
+ else if ((sb->u.minix_sb.s_mount_state & MINIX_ERROR_FS) && (sbi->s_version != MINIX_V3))
+ printk ("MINIX-fs warning: remounting Minix filesystem V%i with errors, "
+ "running fsck is recommended.\n", sbi->s_version);

- if (!(sb->u.minix_sb.s_mount_state & MINIX_VALID_FS))
- printk ("MINIX-fs warning: remounting unchecked fs, "
- "running fsck is recommended.\n");
- else if ((sb->u.minix_sb.s_mount_state & MINIX_ERROR_FS))
- printk ("MINIX-fs warning: remounting fs with errors, "
- "running fsck is recommended.\n");
- }
return 0;
}

@@ -125,6 +133,7 @@
struct buffer_head *bh;
struct buffer_head **map;
struct minix_super_block *ms;
+ struct minix3_super_block *m3s = NULL;
int i, block;
kdev_t dev = s->s_dev;
struct inode *root_inode;
@@ -182,6 +191,20 @@
sbi->s_dirsize = 32;
sbi->s_namelen = 30;
sbi->s_link_max = MINIX2_LINK_MAX;
+ } else if ( *(__u16 *)(bh->b_data + 24) == MINIX3_SUPER_MAGIC) {
+ m3s = (struct minix3_super_block *) bh->b_data;
+ s->s_magic = m3s->s_magic;
+ sbi->s_imap_blocks = m3s->s_imap_blocks;
+ sbi->s_zmap_blocks = m3s->s_zmap_blocks;
+ sbi->s_firstdatazone = m3s->s_firstdatazone;
+ sbi->s_log_zone_size = m3s->s_log_zone_size;
+ sbi->s_max_size = m3s->s_max_size;
+ sbi->s_nzones = m3s->s_zones;
+ sbi->s_dirsize = 64;
+ sbi->s_namelen = 60;
+ sbi->s_version = MINIX_V3;
+ sbi->s_link_max = MINIX2_LINK_MAX;
+ sb_set_blocksize(s, m3s->s_blocksize);
} else
goto out_no_fs;

@@ -224,17 +247,17 @@
if (!NO_TRUNCATE)
s->s_root->d_op = &minix_dentry_operations;

- if (!(s->s_flags & MS_RDONLY)) {
- ms->s_state &= ~MINIX_VALID_FS;
+ if (!(s->s_flags & MS_RDONLY) && (sbi->s_version != MINIX_V3)) {
+ ms->s_state &= ~MINIX_VALID_FS; /* s_state is out from V3 sb */
mark_buffer_dirty(bh);
s->s_dirt = 1;
}
- if (!(sbi->s_mount_state & MINIX_VALID_FS))
- printk ("MINIX-fs: mounting unchecked file system, "
- "running fsck is recommended.\n");
- else if (sbi->s_mount_state & MINIX_ERROR_FS)
- printk ("MINIX-fs: mounting file system with errors, "
- "running fsck is recommended.\n");
+ if (!(sbi->s_mount_state & MINIX_VALID_FS) && (sbi->s_version != MINIX_V3))
+ printk ("MINIX-fs: mounting unchecked Minix filesystem V%i, "
+ "running fsck is recommended.\n", sbi->s_version);
+ else if ((sbi->s_mount_state & MINIX_ERROR_FS) && (sbi->s_version != MINIX_V3))
+ printk ("MINIX-fs: mounting Minix filesystem V%i with errors, "
+ "running fsck is recommended.\n", sbi->s_version);
return s;

out_iput:
@@ -263,7 +286,7 @@

out_no_fs:
if (!silent)
- printk("VFS: Can't find a Minix or Minix V2 filesystem on device "
+ printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 on device "
"%s.\n", kdevname(dev));
out_release:
brelse(bh);
diff -ur orig.linux-2.4.32/fs/minix/itree_common.c updated.linux-2.4.32/fs/minix/itree_common.c
--- orig.linux-2.4.32/fs/minix/itree_common.c 2002-02-25 20:38:09.000000000 +0100
+++ updated.linux-2.4.32/fs/minix/itree_common.c 2006-01-25 16:07:08.000000000 +0100
@@ -21,7 +21,7 @@

static inline block_t *block_end(struct buffer_head *bh)
{
- return (block_t *)((char*)bh->b_data + BLOCK_SIZE);
+ return (block_t *)((char*)bh->b_data + bh->b_size);
}

static inline Indirect *get_branch(struct inode *inode,
@@ -81,7 +81,7 @@
branch[n].key = cpu_to_block(nr);
bh = sb_getblk(inode->i_sb, parent);
lock_buffer(bh);
- memset(bh->b_data, 0, BLOCK_SIZE);
+ memset(bh->b_data, 0, bh->b_size);
branch[n].bh = bh;
branch[n].p = (block_t*) bh->b_data + offsets[n];
*branch[n].p = branch[n].key;
@@ -292,6 +292,7 @@

static inline void truncate (struct inode * inode)
{
+ struct super_block * sb = inode->i_sb;
block_t *idata = i_data(inode);
int offsets[DEPTH];
Indirect chain[DEPTH];
@@ -301,7 +302,7 @@
int first_whole;
long iblock;

- iblock = (inode->i_size + BLOCK_SIZE-1) >> 10;
+ iblock = (inode->i_size + sb->s_blocksize -1) >> 10;
block_truncate_page(inode->i_mapping, inode->i_size, get_block);

n = block_to_path(inode, iblock, offsets);
diff -ur orig.linux-2.4.32/include/linux/minix_fs.h updated.linux-2.4.32/include/linux/minix_fs.h
--- orig.linux-2.4.32/include/linux/minix_fs.h 2001-09-07 18:45:51.000000000 +0200
+++ updated.linux-2.4.32/include/linux/minix_fs.h 2006-01-25 16:07:08.000000000 +0100
@@ -23,14 +23,13 @@
#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 MINIX3_SUPER_MAGIC 0x4d5a /* minix V3 fs */
#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 */
+#define MINIX_V3 0x0003 /* minix V3 fs */

#define INODE_VERSION(inode) inode->i_sb->u.minix_sb.s_version

@@ -82,11 +81,36 @@
__u32 s_zones;
};

+/*
+ * V3 minix super-block data on disk
+ */
+struct minix3_super_block {
+ __u16 s_ninodes;
+ __u16 s_nzones;
+ __u16 s_pad0;
+ __u16 s_imap_blocks;
+ __u16 s_zmap_blocks;
+ __u16 s_firstdatazone;
+ __u16 s_log_zone_size;
+ __u16 s_pad1;
+ __u32 s_max_size;
+ __u32 s_zones;
+ __u16 s_magic;
+ __u16 s_pad2;
+ __u16 s_blocksize;
+ __u8 s_disk_version;
+};
+
struct minix_dir_entry {
__u16 inode;
char name[0];
};

+struct minix3_dir_entry {
+ __u32 inode;
+ char name[0];
+};
+
#ifdef __KERNEL__

/*