/*
* Delete a page from the page cache and free it. Caller has to make
* sure the page is locked and that nobody else uses it - or that usage
* is safe. The caller must hold the mapping's tree_lock and
* mem_cgroup_begin_page_stat().
*/
void __delete_from_page_cache(struct page *page, void *shadow,
struct mem_cgroup *memcg)
{
struct address_space *mapping = page->mapping;
trace_mm_filemap_delete_from_page_cache(page);
/*
* if we're uptodate, flush out into the cleancache, otherwise
* invalidate any existing cleancache entries. We can't leave
* stale data around in the cleancache once our page is gone
*/
if (PageUptodate(page) && PageMappedToDisk(page))
cleancache_put_page(page);
else
cleancache_invalidate_page(mapping, page);
page_cache_tree_delete(mapping, page, shadow);
page->mapping = NULL;
/* Leave page->index set: truncation lookup relies upon it */
/* hugetlb pages do not participate in page cache accounting. */
if (!PageHuge(page))
__dec_zone_page_state(page, NR_FILE_PAGES);
if (PageSwapBacked(page))
__dec_zone_page_state(page, NR_SHMEM);
BUG_ON(page_mapped(page));
/*
* At this point page must be either written or cleaned by truncate.
* Dirty page here signals a bug and loss of unwritten data.
*
* This fixes dirty accounting after removing the page entirely but
* leaves PageDirty set: it has no effect for truncated page and
* anyway will be cleared before returning page into buddy allocator.
*/
if (WARN_ON_ONCE(PageDirty(page)))
account_page_cleaned(page, mapping, memcg,
inode_to_wb(mapping->host));
}
void __delete_from_page_cache(struct page *page)
{
struct address_space *mapping = page->mapping;
if (PageUptodate(page) && PageMappedToDisk(page))
cleancache_put_page(page);
else
cleancache_invalidate_page(mapping, page);
radix_tree_delete(&mapping->page_tree, page->index);
page->mapping = NULL;
mapping->nrpages--;
__dec_zone_page_state(page, NR_FILE_PAGES);
if (PageSwapBacked(page))
__dec_zone_page_state(page, NR_SHMEM);
BUG_ON(page_mapped(page));
if (PageDirty(page) && mapping_cap_account_dirty(mapping)) {
dec_zone_page_state(page, NR_FILE_DIRTY);
dec_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
}
}
