> + partial_end = ((lend + 1) % PAGE_SIZE) > 0;
The > 0 reads a little odd as we can never get a negative value here.
> + shmem_get_folio(inode, lstart >> PAGE_SHIFT, &folio, SGP_READ);
> + if (folio) {
> + bool same_page;
> +
> + same_page = lend < folio_pos(folio) + folio_size(folio);
> + if (same_page)
> + partial_end = false;
> + folio_mark_dirty(folio);
> + if (!truncate_inode_partial_folio(folio, lstart, lend)) {
> + start = folio->index + folio_nr_pages(folio);
> + if (same_page)
> + end = folio->index;
> }
> + folio_unlock(folio);
> + folio_put(folio);
> + folio = NULL;
The entire logic after the shmem_get_folio call is duplicated in
truncate_inode_pages_range. Shouldn't we ty to combine that by moving it
into a helper?
If we can't merge it I think same_page shoud be renamed to same_folio as in
truncate_inode_pages_range.
> pgoff_t start; /* inclusive */
> pgoff_t end; /* exclusive */
> - unsigned int partial_start; /* inclusive */
> - unsigned int partial_end; /* exclusive */
> struct folio_batch fbatch;
> pgoff_t indices[PAGEVEC_SIZE];
> pgoff_t index;
> int i;
> + struct folio * folio;
Weird indentation after the star.
> + bool partial_end;
And the style here in general does not seem to match the existing code.
