mm/filemap: Add __folio_lock_or_retry()

Convert __lock_page_or_retry() to __folio_lock_or_retry().  This actually
saves 4 bytes in the only caller of lock_page_or_retry() (due to better
register allocation) and saves the 14 byte cost of calling page_folio()
in __folio_lock_or_retry() for a total saving of 18 bytes.  Also use
a bool for the return type.

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>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Acked-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>

1 files changed, 10 insertions, 12 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index b17b58c29ed7..706d121ca9cc 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1680,48 +1680,46 @@ static int __folio_lock_async(struct folio *folio, struct wait_page_queue *wait)
 
 /*
  * Return values:
- * 1 - page is locked; mmap_lock is still held.
- * 0 - page is not locked.
+ * true - folio is locked; mmap_lock is still held.
+ * false - folio is not locked.
  *     mmap_lock has been released (mmap_read_unlock(), unless flags had both
  *     FAULT_FLAG_ALLOW_RETRY and FAULT_FLAG_RETRY_NOWAIT set, in
  *     which case mmap_lock is still held.
  *
- * If neither ALLOW_RETRY nor KILLABLE are set, will always return 1
- * with the page locked and the mmap_lock unperturbed.
+ * If neither ALLOW_RETRY nor KILLABLE are set, will always return true
+ * with the folio locked and the mmap_lock unperturbed.
  */
-int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
+bool __folio_lock_or_retry(struct folio *folio, struct mm_struct *mm,
 			 unsigned int flags)
 {
-	struct folio *folio = page_folio(page);
-
 	if (fault_flag_allow_retry_first(flags)) {
 		/*
 		 * CAUTION! In this case, mmap_lock is not released
 		 * even though return 0.
 		 */
 		if (flags & FAULT_FLAG_RETRY_NOWAIT)
-			return 0;
+			return false;
 
 		mmap_read_unlock(mm);
 		if (flags & FAULT_FLAG_KILLABLE)
 			folio_wait_locked_killable(folio);
 		else
 			folio_wait_locked(folio);
-		return 0;
+		return false;
 	}
 	if (flags & FAULT_FLAG_KILLABLE) {
-		int ret;
+		bool ret;
 
 		ret = __folio_lock_killable(folio);
 		if (ret) {
 			mmap_read_unlock(mm);
-			return 0;
+			return false;
 		}
 	} else {
 		__folio_lock(folio);
 	}
 
-	return 1;
+	return true;
 }
 
 /**