Re: [PATCH/RFC] minix filesystem update to V3 for 2.6 kernels

Daniel Aragonés <danarag@xxxxxxxxx> wrote:

Hi Andrew,

As a continuation of my former communication of January 25, and after having posted the attached patch in my personal page http://www.terra.es/personal2/danarag for about 3 months, feedback has come
to me, and some bugs have been detected and corrected.

People use minixfs? I'm a bit surprised.

I believe that now (not before) the patch is really ready for merging into the main line if you consider it appropriate.

We'd need a detailed changelog please.

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

The patch gets lots of rejects. More than I'm prepared to fix up so I can
take a look at it in tkdiff, unfortunately.

I suspect the patch was against some prehistoric kernel like 2.6.16 ;)


@@ -79,24 +96,35 @@
int minix_new_block(struct inode * inode)
{
struct minix_sb_info *sbi = minix_sb(inode->i_sb);
- int i;
+ char *offset = kmalloc(sizeof(char *), GFP_KERNEL);

That's a peculiar thing to do.

+ int num_1K_blocks = (inode->i_sb->s_blocksize)/1024;
+ int bits_per_zone = 8 * (inode->i_sb->s_blocksize);
+ int i, k;

for (i = 0; i < sbi->s_zmap_blocks; i++) {
struct buffer_head *bh = sbi->s_zmap[i];
- int j;
+ for (k = 0; k < num_1K_blocks; k++) {
+ int j;

- lock_kernel();
- if ((j = minix_find_first_zero_bit(bh->b_data, 8192)) < 8192) {
- minix_set_bit(j,bh->b_data);
- unlock_kernel();
- mark_buffer_dirty(bh);
- j += i*8192 + sbi->s_firstdatazone-1;
- if (j < sbi->s_firstdatazone || j >= sbi->s_nzones)
- break;
- return j;
+ offset = (char *)bh->b_data;

And here I think we've just leaked that memory.

+ bit = ino & 8191;
+ ino >>= 13;
+ mask >>= (4-k);
+ if ((ino >> k) >= sbi->s_imap_blocks) {
printk("minix_free_inode: nonexistent imap in superblock\n");
goto out;
}

minix_clear_inode(inode); /* clear on-disk copy */

- bh = sbi->s_imap[ino >> 13];
+ char *offset = kmalloc(sizeof(char *), GFP_KERNEL);
+ bh = sbi->s_imap[ino >> k];
+ offset = (char *)bh->b_data;

And again. Here we've definitely leaked it.

@@ -226,26 +268,36 @@
j = 8192;
bh = NULL;
*error = -ENOSPC;
+ char *offset = kmalloc(sizeof(char *), GFP_KERNEL);
lock_kernel();
for (i = 0; i < sbi->s_imap_blocks; i++) {
bh = sbi->s_imap[i];
- if ((j = minix_find_first_zero_bit(bh->b_data, 8192)) < 8192)
- break;
+ for (k = 0; k < num_1K_blocks; k++) {
+ offset = (char *)bh->b_data;

again


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