mm/filemap: pass a sleep state to put_and_wait_on_page_locked

This is prep work for the next patch, but I think at least one of the
current callers would prefer a killable sleep to an uninterruptible one.

Link: https://lkml.kernel.org/r/20210122160140.223228-6-willy@infradead.orgSigned-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/pagemap.h

@@ -681,8 +681,7 @@ static inline int wait_on_page_locked_killable(struct page *page)
 	return wait_on_page_bit_killable(compound_head(page), PG_locked);
 }
 
-extern void put_and_wait_on_page_locked(struct page *page);
-
+int put_and_wait_on_page_locked(struct page *page, int state);
 void wait_on_page_writeback(struct page *page);
 extern void end_page_writeback(struct page *page);
 void wait_for_stable_page(struct page *page);

mm/filemap.c

@@ -1384,20 +1384,23 @@ static int wait_on_page_locked_async(struct page *page,
 /**
  * put_and_wait_on_page_locked - Drop a reference and wait for it to be unlocked
  * @page: The page to wait for.
+ * @state: The sleep state (TASK_KILLABLE, TASK_UNINTERRUPTIBLE, etc).
  *
  * The caller should hold a reference on @page.  They expect the page to
  * become unlocked relatively soon, but do not wish to hold up migration
  * (for example) by holding the reference while waiting for the page to
  * come unlocked.  After this function returns, the caller should not
  * dereference @page.
+ *
+ * Return: 0 if the page was unlocked or -EINTR if interrupted by a signal.
  */
-void put_and_wait_on_page_locked(struct page *page)
+int put_and_wait_on_page_locked(struct page *page, int state)
 {
 	wait_queue_head_t *q;
 
 	page = compound_head(page);
 	q = page_waitqueue(page);
-	wait_on_page_bit_common(q, page, PG_locked, TASK_UNINTERRUPTIBLE, DROP);
+	return wait_on_page_bit_common(q, page, PG_locked, state, DROP);
 }
 
 /**

mm/huge_memory.c

@@ -1439,7 +1439,7 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd)
 		if (!get_page_unless_zero(page))
 			goto out_unlock;
 		spin_unlock(vmf->ptl);
-		put_and_wait_on_page_locked(page);
+		put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE);
 		goto out;
 	}
 
@@ -1475,7 +1475,7 @@ vm_fault_t do_huge_pmd_numa_page(struct vm_fault *vmf, pmd_t pmd)
 		if (!get_page_unless_zero(page))
 			goto out_unlock;
 		spin_unlock(vmf->ptl);
-		put_and_wait_on_page_locked(page);
+		put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE);
 		goto out;
 	}
 

mm/migrate.c

@@ -331,7 +331,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep,
 	if (!get_page_unless_zero(page))
 		goto out;
 	pte_unmap_unlock(ptep, ptl);
-	put_and_wait_on_page_locked(page);
+	put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE);
 	return;
 out:
 	pte_unmap_unlock(ptep, ptl);
@@ -365,7 +365,7 @@ void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd)
 	if (!get_page_unless_zero(page))
 		goto unlock;
 	spin_unlock(ptl);
-	put_and_wait_on_page_locked(page);
+	put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE);
 	return;
 unlock:
 	spin_unlock(ptl);