This morning I needed to read a Minix V3 filesystem,
but unfortunately my 2.6.19 did not support that,
and neither did the downloaded 2.6.20rc4.
Fortunately, google told me that Daniel Aragones had
already done the work, patch found at
http://www.terra.es/personal2/danarag/
Unfortunaly, looking at the patch was painful to my eyes,
so I polished it a bit before applying. The resulting
kernel boots, and reads the filesystem it needed to read.
(So, I do not guarantee the patch below, it is almost untested,
writing is entirely untested, but it certainly contains fewer
bugs than the patch found at the url above.
The patch is relative to 2.6.20rc4.)
Andries
diff -uprN -X /linux/dontdiff a/fs/minix/bitmap.c b/fs/minix/bitmap.c
--- a/fs/minix/bitmap.c 2006-11-30 14:56:42.0 +0100
+++ b/fs/minix/bitmap.c 2007-01-08 18:16:02.879794568 +0100
@@ -26,14 +26,14 @@ static unsigned long count_free(struct b
for (i=0; ib_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; jb_data[j] & 0xf]
+ nibblemap[(bh->b_data[j]>>4) & 0xf];
@@ -48,28 +48,29 @@ static unsigned long count_free(struct b
return(sum);
}
-void minix_free_block(struct inode * inode, int block)
+void minix_free_block(struct inode *inode, unsigned long block)
{
- struct super_block * sb = inode->i_sb;
- struct minix_sb_info * sbi = minix_sb(sb);
- struct buffer_head * bh;
- unsigned int bit,zone;
+ struct super_block *sb = inode->i_sb;
+ struct minix_sb_info *sbi = minix_sb(sb);
+ struct buffer_head *bh;
+ int k = sb->s_blocksize_bits + 3;
+ unsigned long bit, zone;
if (block < sbi->s_firstdatazone || block >= sbi->s_nzones) {
printk("Trying to free block not in datazone\n");
return;
}
zone = block - sbi->s_firstdatazone + 1;
- bit = zone & 8191;
- zone >>= 13;
+ bit = zone & ((1<>= k;
if (zone >= sbi->s_zmap_blocks) {
printk("minix_free_block: nonexistent bitmap buffer\n");
return;
}
bh = sbi->s_zmap[zone];
lock_kernel();
- if (!minix_test_and_clear_bit(bit,bh->b_data))
- printk("free_block (%s:%d): bit already cleared\n",
+ if (!minix_test_and_clear_bit(bit, bh->b_data))
+ printk("minix_free_block (%s:%lu): bit already cleared\n",
sb->s_id, block);
unlock_kernel();
mark_buffer_dirty(bh);
@@ -79,6 +80,7 @@ void minix_free_block(struct inode * ino
int minix_new_block(struct inode * inode)
{
struct minix_sb_info *sbi = minix_sb(inode->i_sb);
+ int bits_per_zone = 8 * inode->i_sb->s_blocksize;
int i;
for (i = 0; i < sbi->s_zmap_blocks; i++) {
@@ -86,11 +88,12 @@ int minix_new_block(struct inode * inode
int j;
lock_kernel();
- if ((j = minix_find_first_zero_bit(bh->b_data, 8192)) < 8192) {
- minix_set_bit(j,bh->b_data);
+ j = minix_find_first_zero_bit(bh->b_data, bits_per_zone);
+ if (j < bits_per_zone) {
+ minix_set_bit(j, bh->b_data);
unlock_kernel();
mark_buffer_dirty(bh);
- j += i*8192 + sbi->s_firstdatazone-1;
+ j += i * bits_per_zone + sbi->s_firstdatazone-1;
if (j < sbi->s_firstdatazone || j >= sbi->s_nzones)
break;
return j;
@@ -137,6 +140,7 @@ minix_V2_raw_inode(struct super_block *s
int block;
struct minix_sb_info *sbi = minix_sb(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) {
@@ -146,14 +150,14 @@ minix_V2_raw_inode(struct super_block *s
}
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 inode 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. */
@@ -185,26 +189,30 @@ static void minix_clear_inode(struct ino
void minix_free_inode(struct inode * inode)
{
+ struct super_block *sb = inode->i_sb;
struct min
