[PATCH v14 020/138] mm/filemap: Add __folio_lock_async()
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Date: 2021-07-15 03:54:58
Also in:
linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), memory management, page cache, the rest · Maintainers:
Alexander Viro, Christian Brauner, Andrew Morton, Matthew Wilcox, Linus Torvalds
There aren't any actual callers of lock_page_async(), so remove it. Convert filemap_update_page() to call __folio_lock_async(). __folio_lock_async() is 21 bytes smaller than __lock_page_async(), but the real savings come from using a folio in filemap_update_page(), shrinking it from 515 bytes to 404 bytes, saving 110 bytes. The text shrinks by 132 bytes in total. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Jeff Layton <jlayton@kernel.org> Acked-by: Kirill A. Shutemov <redacted> Acked-by: Vlastimil Babka <redacted> Reviewed-by: William Kucharski <redacted> Reviewed-by: David Howells <dhowells@redhat.com> --- fs/io_uring.c | 2 +- include/linux/pagemap.h | 17 ----------------- mm/filemap.c | 31 ++++++++++++++++--------------- 3 files changed, 17 insertions(+), 33 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index d94fb5835a20..7e30c7c361e6 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c@@ -3149,7 +3149,7 @@ static int io_read_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) } /* - * This is our waitqueue callback handler, registered through lock_page_async() + * This is our waitqueue callback handler, registered through __folio_lock_async() * when we initially tried to do the IO with the iocb armed our waitqueue. * This gets called when the page is unlocked, and we generally expect that to * happen when the page IO is completed and the page is now uptodate. This will
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 88727c74e059..6f631a3e42dc 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h@@ -655,7 +655,6 @@ static inline bool wake_page_match(struct wait_page_queue *wait_page, void __folio_lock(struct folio *folio); int __folio_lock_killable(struct folio *folio); -extern int __lock_page_async(struct page *page, struct wait_page_queue *wait); extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm, unsigned int flags); void unlock_page(struct page *page);
@@ -712,22 +711,6 @@ static inline int lock_page_killable(struct page *page) return folio_lock_killable(page_folio(page)); } -/* - * lock_page_async - Lock the page, unless this would block. If the page - * is already locked, then queue a callback when the page becomes unlocked. - * This callback can then retry the operation. - * - * Returns 0 if the page is locked successfully, or -EIOCBQUEUED if the page - * was already locked and the callback defined in 'wait' was queued. - */ -static inline int lock_page_async(struct page *page, - struct wait_page_queue *wait) -{ - if (!trylock_page(page)) - return __lock_page_async(page, wait); - return 0; -} - /* * lock_page_or_retry - Lock the page, unless this would block and the * caller indicated that it can handle a retry.
diff --git a/mm/filemap.c b/mm/filemap.c
index 962db5c38cd7..c97b804811fc 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c@@ -1597,18 +1597,18 @@ int __folio_lock_killable(struct folio *folio) } EXPORT_SYMBOL_GPL(__folio_lock_killable); -int __lock_page_async(struct page *page, struct wait_page_queue *wait) +static int __folio_lock_async(struct folio *folio, struct wait_page_queue *wait) { - struct wait_queue_head *q = page_waitqueue(page); + struct wait_queue_head *q = page_waitqueue(&folio->page); int ret = 0; - wait->page = page; + wait->page = &folio->page; wait->bit_nr = PG_locked; spin_lock_irq(&q->lock); __add_wait_queue_entry_tail(q, &wait->wait); - SetPageWaiters(page); - ret = !trylock_page(page); + folio_set_waiters(folio); + ret = !folio_trylock(folio); /* * If we were successful now, we know we're still on the * waitqueue as we're still under the lock. This means it's
@@ -2381,41 +2381,42 @@ static int filemap_update_page(struct kiocb *iocb, struct address_space *mapping, struct iov_iter *iter, struct page *page) { + struct folio *folio = page_folio(page); int error; - if (!trylock_page(page)) { + if (!folio_trylock(folio)) { if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_NOIO)) return -EAGAIN; if (!(iocb->ki_flags & IOCB_WAITQ)) { - put_and_wait_on_page_locked(page, TASK_KILLABLE); + put_and_wait_on_page_locked(&folio->page, TASK_KILLABLE); return AOP_TRUNCATED_PAGE; } - error = __lock_page_async(page, iocb->ki_waitq); + error = __folio_lock_async(folio, iocb->ki_waitq); if (error) return error; } - if (!page->mapping) + if (!folio->mapping) goto truncated; error = 0; - if (filemap_range_uptodate(mapping, iocb->ki_pos, iter, page)) + if (filemap_range_uptodate(mapping, iocb->ki_pos, iter, &folio->page)) goto unlock; error = -EAGAIN; if (iocb->ki_flags & (IOCB_NOIO | IOCB_NOWAIT | IOCB_WAITQ)) goto unlock; - error = filemap_read_page(iocb->ki_filp, mapping, page); + error = filemap_read_page(iocb->ki_filp, mapping, &folio->page); if (error == AOP_TRUNCATED_PAGE) - put_page(page); + folio_put(folio); return error; truncated: - unlock_page(page); - put_page(page); + folio_unlock(folio); + folio_put(folio); return AOP_TRUNCATED_PAGE; unlock: - unlock_page(page); + folio_unlock(folio); return error; }
--
2.30.2