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Daniel

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More options Jan 11 2006, 6:18 pm

Newsgroups: comp.os.minix

From: "Daniel" <dana...@gmail.com>

Date: 11 Jan 2006 15:18:47 -0800

Local: Wed, Jan 11 2006 6:18 pm

Subject: [PATCH] Update for Linux kernel 2.6.x.y to support Minix V3 filesystem

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This patch I submit compiles cleanly and works fine under i386
arquitecture. I have tested it with blocksizes of 1024, 2048 and 4096
bytes. The backwards compatibility has been tested only with diskettes
V1 and V2. More testing is needed, of course, but it looks nice by now.

The references to the old fixed size blocks have been changed to
multiple sizes. Also, the padding needed to allow for 60 characters
long names in the directory entries of 64 bytes, has needed noticeable
changes in the file dir.c. The reference to s_state in the superblock
is now removed from version 3. Also, some relocations are new in the
superblock.

I hope this patch helps to understand what is inside a Minix 3
partition and subpartitions. I expect to read your suggestions to
improve the patch.

========================

diff -ur orig.linux-2.6.14.5/fs/minix/bitmap.c
updated.linux-2.6.14.5/fs/minix/bitmap.c
--- orig.linux-2.6.14.5/fs/minix/bitmap.c 2005-12-27 01:26:33.000000000
+0100
+++ updated.linux-2.6.14.5/fs/minix/bitmap.c 2006-01-11
19:41:41.000000000 +0100
@@ -26,14 +26,14 @@
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];
@@ -145,15 +145,15 @@
return NULL;
}
ino--;
- block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
- ino / MINIX2_INODES_PER_BLOCK;
+ block = 2 + sbi->s_imap_blocks + sbi->s_zmap_blocks +
+ ino / MINIX2_INODES_PER_BLOCK(sb->s_blocksize);
*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(sb->s_blocksize);
}

/* Clear the link count and mode of a deleted inode on disk. */
diff -ur orig.linux-2.6.14.5/fs/minix/dir.c
updated.linux-2.6.14.5/fs/minix/dir.c
--- orig.linux-2.6.14.5/fs/minix/dir.c 2005-12-27 01:26:33.000000000
+0100
+++ updated.linux-2.6.14.5/fs/minix/dir.c 2006-01-11 19:41:41.000000000
+0100
@@ -4,6 +4,8 @@
* Copyright (C) 1991, 1992 Linus Torvalds
*
* minix directory handling functions
+ *
+ * Updated to filesystem version 3 by Daniel Aragones
*/

#include "minix.h"
@@ -11,6 +13,7 @@
#include <linux/smp_lock.h>

typedef struct minix_dir_entry minix_dirent;
+typedef struct minix3_dir_entry minix3_dirent;

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

@@ -108,14 +111,22 @@
limit = kaddr + minix_last_byte(inode, n) - chunk_size;
for ( ; p <= limit ; p = minix_next_entry(p, sbi)) {
minix_dirent *de = (minix_dirent *)p;
+ minix3_dirent *de3 = (minix3_dirent *)p;
if (de->inode) {
int over;
- unsigned l = strnlen(de->name,sbi->s_namelen);
-
- offset = p - kaddr;
- over = filldir(dirent, de->name, l,
- (n<<PAGE_CACHE_SHIFT) | offset,
- de->inode, DT_UNKNOWN);
+ if (!(sbi->s_version == MINIX_V3)) {
+ unsigned l = strnlen(de->name,sbi->s_namelen);
+ offset = p - kaddr;
+ over = filldir(dirent, de->name, l,
+ (n<<PAGE_CACHE_SHIFT) | offset,
+ de->inode, DT_UNKNOWN);
+ } else {
+ unsigned l = strnlen(de3->name,sbi->s_namelen);
+ offset = p - kaddr;
+ over = filldir(dirent, de3->name, l,
+ (n<<PAGE_CACHE_SHIFT) | offset,
+ de3->inode, DT_UNKNOWN);
+ }
if (over) {
dir_put_page(page);
goto done;
@@ -158,7 +169,7 @@
unsigned long npages = dir_pages(dir);
struct page *page = NULL;
struct minix_dir_entry *de;
-
+ struct minix3_dir_entry *de3;
*res_page = NULL;

for (n = 0; n < npages; n++) {
@@ -169,17 +180,26 @@

kaddr = (char*)page_address(page);
de = (struct minix_dir_entry *) kaddr;
+ de3 = (struct minix3_dir_entry *) kaddr;
kaddr += minix_last_byte(dir, n) - sbi->s_dirsize;
- for ( ; (char *) de <= kaddr ; de = minix_next_entry(de,sbi)) {
- if (!de->inode)
- continue;
- if (namecompare(namelen,sbi->s_namelen,name,de->name))
- goto found;
+ for ( ; (char *) de <= kaddr ;
+ de = minix_next_entry(de,sbi),
+ de3 = minix_next_entry(de3,sbi)) {
+ if (!(sbi->s_version == MINIX_V3)) {
+ if (!de->inode)
+ continue;
+ if (namecompare(namelen,sbi->s_namelen,name,de->name))
+ goto found;
+ } else {
+ if (!de3->inode)
+ continue;
+ if (namecompare(namelen,sbi->s_namelen,name,de3->name))
+ goto found;
+ }
}
dir_put_page(page);
}
return NULL;
-
found:
*res_page = page;
return de;
@@ -194,6 +214,7 @@
struct minix_sb_info * sbi = minix_sb(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;
@@ -216,6 +237,7 @@
kaddr = (char*)page_address(page);
dir_end = kaddr + minix_last_byte(dir, n);
de = (minix_dirent *)kaddr;
+ de3 = (minix3_dirent *)kaddr;
kaddr += PAGE_CACHE_SIZE - sbi->s_dirsize;
while ((char *)de <= kaddr) {
if ((char *)de == dir_end) {
@@ -226,9 +248,16 @@
if (!de->inode)
goto got_it;
err = -EEXIST;
- if (namecompare(namelen,sbi->s_namelen,name,de->name))
- goto out_unlock;
- de = minix_next_entry(de, sbi);
+ if (!(sbi->s_version == MINIX_V3)) {
+ if (namecompare(namelen,sbi->s_namelen,name,de->name))
+ goto out_unlock;
+ de = minix_next_entry(de, sbi);
+ } else {
+ if (namecompare(namelen,sbi->s_namelen,name,de3->name))
+ goto out_unlock;
+ de = minix_next_entry(de, sbi);
+ de3 = minix_next_entry(de3, sbi);
+ }
}
unlock_page(page);
dir_put_page(page);
@@ -242,9 +271,15 @@
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;
+ if (!(sbi->s_version == MINIX_V3)) {
+ memcpy (de->name, name, namelen);
+ memset (de->name + namelen, 0, sbi->s_dirsize - namelen - 2);
+ de->inode = inode->i_ino;
+ } else {
+ memcpy (de3->name, name, namelen);
+ memset (de3->name + namelen, 0, sbi->s_dirsize - namelen - 4);
+ de3->inode = inode->i_ino;
+ }
err = dir_commit_chunk(page, from, to);
dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
mark_inode_dirty(dir);
@@ -286,6 +321,7 @@
struct page *page = grab_cache_page(mapping, 0);
struct minix_sb_info * sbi = minix_sb(inode->i_sb);
struct minix_dir_entry * de;
+ struct minix3_dir_entry * de3;
char *kaddr;
int err;

@@ -301,11 +337,13 @@
memset(kaddr, 0, PAGE_CACHE_SIZE);

de = (struct minix_dir_entry *)kaddr;
- de->inode = inode->i_ino;
- strcpy(de->name,".");
+ de3 = (struct minix3_dir_entry *)kaddr;
+ de->inode = de3->inode = inode->i_ino;
+ (sbi->s_version == MINIX_V3) ? strcpy(de3->name,".") :
strcpy(de->name,".");
de = minix_next_entry(de, sbi);
- de->inode = dir->i_ino;
- strcpy(de->name,"..");
+ de3 = minix_next_entry(de3, sbi);
+ de->inode = de3->inode = dir->i_ino;
+ (sbi->s_version == MINIX_V3) ? strcpy(de3->name,"..") :
strcpy(de->name,"..");
kunmap_atomic(kaddr, KM_USER0);

err = dir_commit_chunk(page, 0, 2 * sbi->s_dirsize);
@@ -326,27 +364,42 @@
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 += minix_last_byte(inode, i) - sbi->s_dirsize;

while ((char *)de <= kaddr) {
if (de->inode != 0) {
/* check for . and .. */
- if (de->name[0] != '.')
- goto not_empty;
- if (!de->name[1]) {
- if (de->inode != inode->i_ino)
+ if (!(sbi->s_version == MINIX_V3)) {
+ if (de->name[0] != '.')
+ goto not_empty;
+ if (!de->name[1]) {
+ if (de->inode != inode->i_ino)
+ goto not_empty;
+ } else if (de->name[1] != '.')
+ goto not_empty;
+ else if (de->name[2])
+ goto not_empty;
+ } else {
+ if (de3->name[0] != '.')
goto not_empty;
- } else if (de->name[1] != '.')
- goto not_empty;
- else if (de->name[2])
- goto not_empty;
+ if (!de3->name[1]) {
+ if (de3->inode != inode->i_ino)
+ goto not_empty;
+ } else if (de3->name[1] != '.')
+ goto not_empty;
+ else if (de3->name[2])
+ goto not_empty;
+ }
}
de = minix_next_entry(de, sbi);
}
diff -ur orig.linux-2.6.14.5/fs/minix/inode.c
updated.linux-2.6.14.5/fs/minix/inode.c
--- orig.linux-2.6.14.5/fs/minix/inode.c 2005-12-27 01:26:33.000000000
+0100
+++ updated.linux-2.6.14.5/fs/minix/inode.c 2006-01-11
19:41:41.000000000 +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>
@@ -36,7 +37,8 @@
struct minix_sb_info *sbi = minix_sb(sb);

if (!(sb->s_flags & MS_RDONLY)) {
- sbi->s_ms->s_state = sbi->s_mount_state;
+ if (sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
+ sbi->s_ms->s_state = sbi->s_mount_state;
mark_buffer_dirty(sbi->s_sbh);
}
for (i = 0; i < sbi->s_imap_blocks; i++)
@@ -117,21 +119,23 @@
!(sbi->s_mount_state & MINIX_VALID_FS))
return 0;
/* Mounting a rw partition read-only. */
- ms->s_state = sbi->s_mount_state;
+ if (sbi->s_version != MINIX_V3)
+ ms->s_state = sbi->s_mount_state;
mark_buffer_dirty(sbi->s_sbh);
} else {
/* Mount a partition which is read-only, read-write. */
sbi->s_mount_state = ms->s_state;
- ms->s_state &= ~MINIX_VALID_FS;
+ if (sbi->s_version != MINIX_V3)
+ ms->s_state &= ~MINIX_VALID_FS;
mark_buffer_dirty(sbi->s_sbh);

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

@@ -197,6 +201,23 @@
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) {
+
+ s->s_magic = MINIX3_SUPER_MAGIC;
+ sbi->s_imap_blocks = *(__u16 *)(bh->b_data + 6);
+ sbi->s_zmap_blocks = *(__u16 *)(bh->b_data + 8);
+ sbi->s_firstdatazone = *(__u16 *)(bh->b_data + 10);
+ sbi->s_log_zone_size = *(__u16 *)(bh->b_data + 12);
+ sbi->s_max_size = *(__u32 *)(bh->b_data + 16);
+ sbi->s_nzones = *(__u32 *)(bh->b_data + 20);
+ sbi->s_dirsize = 64;
+ sbi->s_namelen = 60;
+ sbi->s_version = MINIX_V3;
+ sbi->s_link_max = MINIX2_LINK_MAX;
+ if ( *(__u16 *)(bh->b_data + 28) != 1024) {
+ if (!sb_set_blocksize(s,( *(__u16 *)(bh->b_data + 28))))
+ goto out_bad_hblock;
+ }
} else
goto out_no_fs;

@@ -240,15 +261,16 @@
s->s_root->d_op = &minix_dentry_operations;

if (!(s->s_flags & MS_RDONLY)) {
- ms->s_state &= ~MINIX_VALID_FS;
+ if(sbi->s_version != MINIX_V3) /* s_state is now out from V3 sb */
+ ms->s_state &= ~MINIX_VALID_FS;
mark_buffer_dirty(bh);
}
- 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 0;

out_iput:
@@ -277,8 +299,8 @@

out_no_fs:
if (!silent)
- printk("VFS: Can't find a Minix or Minix V2 filesystem on device "
- "%s.\n", s->s_id);
+ printk("VFS: Can't find a Minix filesystem V1 | V2 | V3 on device "
+ "%s.\n", s->s_id);
out_release:
brelse(bh);
goto out;
@@ -536,12 +558,14 @@

int minix_getattr(struct vfsmount *mnt, struct dentry *dentry, struct
kstat *stat)
{
+ struct inode * dir = dentry->d_parent->d_inode;
+ struct super_block * sb = dir->i_sb;
generic_fillattr(dentry->d_inode, stat);
if (INODE_VERSION(dentry->d_inode) == MINIX_V1)
stat->blocks = (BLOCK_SIZE / 512) * V1_minix_blocks(stat->size);
else
- stat->blocks = (BLOCK_SIZE / 512) * V2_minix_blocks(stat->size);
- stat->blksize = BLOCK_SIZE;
+ stat->blocks = (sb->s_blocksize / 512) *
V2_minix_blocks(stat->size);
+ stat->blksize = sb->s_blocksize;
return 0;
}

diff -ur orig.linux-2.6.14.5/fs/minix/itree_common.c
updated.linux-2.6.14.5/fs/minix/itree_common.c
--- orig.linux-2.6.14.5/fs/minix/itree_common.c 2005-12-27
01:26:33.000000000 +0100
+++ updated.linux-2.6.14.5/fs/minix/itree_common.c 2006-01-11
19:41:41.000000000 +0100
@@ -23,7 +23,7 @@

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,
@@ -85,7 +85,7 @@
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-2.6.14.5/fs/minix/minix.h
updated.linux-2.6.14.5/fs/minix/minix.h
--- orig.linux-2.6.14.5/fs/minix/minix.h 2005-12-27 01:26:33.000000000
+0100
+++ updated.linux-2.6.14.5/fs/minix/minix.h 2006-01-11
19:41:41.000000000 +0100
@@ -12,6 +12,7 @@

#define MINIX_V1 0x0001 /* original minix fs */
#define MINIX_V2 0x0002 /* minix V2 fs */
+#define MINIX_V3 0x0003 /* minix V3 fs */

/*
* minix fs inode data in memory
diff -ur orig.linux-2.6.14.5/include/linux/minix_fs.h
updated.linux-2.6.14.5/include/linux/minix_fs.h
--- orig.linux-2.6.14.5/include/linux/minix_fs.h 2005-12-27
01:26:33.000000000 +0100
+++ updated.linux-2.6.14.5/include/linux/minix_fs.h 2006-01-11
19:41:41.000000000 +0100
@@ -23,11 +23,12 @@
#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 MINIX2_INODES_PER_BLOCK(b) ((b)/(sizeof (struct
minix2_inode)))

/*
* This is the original minix inode layout on disk.
@@ -82,4 +83,9 @@
char name[0];
};

+struct minix3_dir_entry {
+ __u16 inode;
+ __u16 padding;
+ char name[0];
+};
#endif

=================

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