mm: convert find_get_entry to return the head page
There are only four callers remaining of find_get_entry(). get_shadow_from_swap_cache() only wants to see shadow entries and doesn't care about which page is returned. Push the find_subpage() call into find_lock_entry(), find_get_incore_page() and pagecache_get_page(). [willy@infradead.org: fix oops] Link: https://lkml.kernel.org/r/20200914112738.GM6583@casper.infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Huang Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Link: https://lkml.kernel.org/r/20200910183318.20139-7-willy@infradead.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
9dfc8ff34b
commit
a6de4b4873
13
mm/filemap.c
13
mm/filemap.c
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@ -1645,19 +1645,19 @@ EXPORT_SYMBOL(page_cache_prev_miss);
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/**
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/**
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* find_get_entry - find and get a page cache entry
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* find_get_entry - find and get a page cache entry
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* @mapping: the address_space to search
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* @mapping: the address_space to search
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* @offset: the page cache index
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* @index: The page cache index.
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*
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*
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* Looks up the page cache slot at @mapping & @offset. If there is a
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* Looks up the page cache slot at @mapping & @offset. If there is a
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* page cache page, it is returned with an increased refcount.
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* page cache page, the head page is returned with an increased refcount.
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*
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*
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* If the slot holds a shadow entry of a previously evicted page, or a
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* If the slot holds a shadow entry of a previously evicted page, or a
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* swap entry from shmem/tmpfs, it is returned.
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* swap entry from shmem/tmpfs, it is returned.
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*
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*
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* Return: the found page or shadow entry, %NULL if nothing is found.
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* Return: The head page or shadow entry, %NULL if nothing is found.
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*/
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*/
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struct page *find_get_entry(struct address_space *mapping, pgoff_t offset)
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struct page *find_get_entry(struct address_space *mapping, pgoff_t index)
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{
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{
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XA_STATE(xas, &mapping->i_pages, offset);
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XA_STATE(xas, &mapping->i_pages, index);
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struct page *page;
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struct page *page;
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rcu_read_lock();
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rcu_read_lock();
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@ -1685,7 +1685,6 @@ struct page *find_get_entry(struct address_space *mapping, pgoff_t offset)
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put_page(page);
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put_page(page);
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goto repeat;
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goto repeat;
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}
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}
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page = find_subpage(page, offset);
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out:
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out:
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rcu_read_unlock();
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rcu_read_unlock();
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@ -1722,6 +1721,7 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset)
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put_page(page);
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put_page(page);
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goto repeat;
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goto repeat;
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}
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}
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page = find_subpage(page, offset);
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VM_BUG_ON_PAGE(page_to_pgoff(page) != offset, page);
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VM_BUG_ON_PAGE(page_to_pgoff(page) != offset, page);
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}
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}
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return page;
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return page;
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@ -1768,6 +1768,7 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
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page = NULL;
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page = NULL;
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if (!page)
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if (!page)
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goto no_page;
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goto no_page;
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page = find_subpage(page, index);
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if (fgp_flags & FGP_LOCK) {
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if (fgp_flags & FGP_LOCK) {
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if (fgp_flags & FGP_NOWAIT) {
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if (fgp_flags & FGP_NOWAIT) {
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@ -431,8 +431,10 @@ struct page *find_get_incore_page(struct address_space *mapping, pgoff_t index)
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struct swap_info_struct *si;
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struct swap_info_struct *si;
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struct page *page = find_get_entry(mapping, index);
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struct page *page = find_get_entry(mapping, index);
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if (!xa_is_value(page))
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if (!page)
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return page;
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return page;
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if (!xa_is_value(page))
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return find_subpage(page, index);
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if (!shmem_mapping(mapping))
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if (!shmem_mapping(mapping))
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return NULL;
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return NULL;
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