mm/filemap: Add __folio_lock_async()

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 <kirill.shutemov@linux.intel.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
This commit is contained in:
Matthew Wilcox (Oracle) 2020-12-30 17:58:40 -05:00
parent af7f29d9e1
commit ffdc8dabf2
3 changed files with 15 additions and 31 deletions

View File

@ -3364,7 +3364,7 @@ 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

View File

@ -654,7 +654,6 @@ 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);
@ -711,22 +710,6 @@ 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.

View File

@ -1652,18 +1652,18 @@ 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
@ -2436,6 +2436,7 @@ 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 (iocb->ki_flags & IOCB_NOWAIT) {
@ -2445,40 +2446,40 @@ static int filemap_update_page(struct kiocb *iocb,
filemap_invalidate_lock_shared(mapping);
}
if (!trylock_page(page)) {
if (!folio_trylock(folio)) {
error = -EAGAIN;
if (iocb->ki_flags & (IOCB_NOWAIT | IOCB_NOIO))
goto unlock_mapping;
if (!(iocb->ki_flags & IOCB_WAITQ)) {
filemap_invalidate_unlock_shared(mapping);
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)
goto unlock_mapping;
}
error = AOP_TRUNCATED_PAGE;
if (!page->mapping)
if (!folio->mapping)
goto unlock;
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);
goto unlock_mapping;
unlock:
unlock_page(page);
folio_unlock(folio);
unlock_mapping:
filemap_invalidate_unlock_shared(mapping);
if (error == AOP_TRUNCATED_PAGE)
put_page(page);
folio_put(folio);
return error;
}