[PATCH 1/3] mm: Pass a sleep state to put_and_wait_on_page_locked

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

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.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 include/linux/pagemap.h | 3 +--
 mm/filemap.c            | 7 +++++--
 mm/huge_memory.c        | 4 ++--
 mm/migrate.c            | 4 ++--
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 853733286138..a9ed9ac86e0f 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -618,8 +618,7 @@ 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);
diff --git a/mm/filemap.c b/mm/filemap.c
index 0ef06d515532..f70227941627 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1265,20 +1265,23 @@ 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);
 }
 
 /**
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 7ff29cc3d55c..4b85729016b2 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1398,7 +1398,7 @@ 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;
 	}
 
@@ -1434,7 +1434,7 @@ 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;
 	}
 
diff --git a/mm/migrate.c b/mm/migrate.c
index 941b89383cf3..ac18bbbd8347 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -335,7 +335,7 @@ 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);
@@ -369,7 +369,7 @@ 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);
-- 
2.28.0