Re: JFS resize=0 problem in 2.6.0

Christophe Saout
2004-01-02T22:33:22Z

Am So, den 28.12.2003 schrieb lkml@dhtns.com um 16:30:

> Let me know if I'm missing the goal of the code here, but lines 261-273
> of linux-2.6.0/fs/jfs/super.c are:
>
> case Opt_resize:
> {
> char *resize = args[0].from;
> if (!resize || !*resize) { /* LINE 264 HERE */
> *newLVSize = sb->s_bdev->bd_inode->i_size >>
> sb->s_blocksize_bits;
> if (*newLVSize == 0)
> printk(KERN_ERR
> "JFS: Cannot determine volume size\n");
> } else
> *newLVSize = simple_strtoull(resize, &resize, 0);
> break;
> }
>
> It seems to me that line 264 is attempting to test for the mount
> paramater "resize=0", and when it comes across this, resize to the full
> size of the volume. However, this doesn't work. I believe it should
> test for the char '0' (*resize=='0'), not against literal zero.

literal zero is the end of the string.

So the code checks for resize= and not resize=0.

I think your fix is wrong because it would also recognize resize=0123
because it only tests the first character.

- if (!resize || !*resize) {
+ if (!resize || !*resize || *resize=='0')

It should probably be

+ if (!resize || !*resize || (*resize=='0' && !resize[1]))

Or better: check the integer value that is returned by simple_strtoull.

But did you test what resize= does?