On 10/20/23 21:37, Matthew Wilcox wrote:
On Mon, Sep 18, 2023 at 01:04:56PM +0200, Hannes Reinecke wrote:
Use accessor functions block_index_to_sector() and block_sector_to_index()
to translate the page index into the block sector and vice versa.
You missed two in grow_dev_page() (which I just happened upon):
bh = folio_buffers(folio);
if (bh) {
if (bh->b_size == size) {
end_block = folio_init_buffers(folio, bdev,
(sector_t)index << sizebits, size);
goto done;
}
...
spin_lock(&inode->i_mapping->private_lock);
link_dev_buffers(folio, bh);
end_block = folio_init_buffers(folio, bdev,
(sector_t)index << sizebits, size);
Can UBSAN be of help here? It should catch shifting by a negative
amount. That sizebits is calculated in grow_buffers:
sizebits = PAGE_SHIFT - __ffs(size);
Ah, thanks. I'm currently working with Luis and Pankay to get a combined
patchset; I'll make sure to have that included.
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman
