readahead: Use a folio in read_pages()

Handle multi-page folios correctly and removes a few calls to
compound_head().

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Matthew Wilcox (Oracle) 2022-03-31 14:15:59 -04:00
parent 2ca456c248
commit a42634a6c0

View File

@ -145,7 +145,7 @@ EXPORT_SYMBOL_GPL(file_ra_state_init);
static void read_pages(struct readahead_control *rac)
{
const struct address_space_operations *aops = rac->mapping->a_ops;
struct page *page;
struct folio *folio;
struct blk_plug plug;
if (!readahead_count(rac))
@ -156,24 +156,23 @@ static void read_pages(struct readahead_control *rac)
if (aops->readahead) {
aops->readahead(rac);
/*
* Clean up the remaining pages. The sizes in ->ra
* Clean up the remaining folios. The sizes in ->ra
* may be used to size the next readahead, so make sure
* they accurately reflect what happened.
*/
while ((page = readahead_page(rac))) {
rac->ra->size -= 1;
if (rac->ra->async_size > 0) {
rac->ra->async_size -= 1;
delete_from_page_cache(page);
while ((folio = readahead_folio(rac)) != NULL) {
unsigned long nr = folio_nr_pages(folio);
rac->ra->size -= nr;
if (rac->ra->async_size >= nr) {
rac->ra->async_size -= nr;
filemap_remove_folio(folio);
}
unlock_page(page);
put_page(page);
folio_unlock(folio);
}
} else {
while ((page = readahead_page(rac))) {
aops->readpage(rac->file, page);
put_page(page);
}
while ((folio = readahead_folio(rac)))
aops->readpage(rac->file, &folio->page);
}
blk_finish_plug(&plug);