On Tuesday January 23, [EMAIL PROTECTED] wrote:
> I think your patch is not enough to slove the read_page error
> completely. I think in the bitmap_init_from_disk we also need to check
> the 'count' never exceeds the size of file before calling the
> read_page function. How do your think about it.
> Thanks your reply.
bitmap_init_from_disk already has a test:
if (file && i_size_read(file->f_mapping->host) < bytes +
sizeof(bitmap_super_t)) {
printk(KERN_INFO "%s: bitmap file too short %lu < %lu\n",
bmname(bitmap),
(unsigned long) i_size_read(file->f_mapping->host),
bytes + sizeof(bitmap_super_t));
goto out;
}
so 'bytes' of the bitmap must fit entirely within the file, and count
is set:
if (index == num_pages-1)
count = bytes + sizeof(bitmap_super_t)
- index * PAGE_SIZE;
else
count = PAGE_SIZE;
which ensures that it will not go beyond the end of the file.
So I don't think count can ever exceed the size of the file in this
case.
Can you still see a problem?
Thanks,
NeilBrown
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