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Message-Id: <20201216182335.27227-22-willy@infradead.org>
Date: Wed, 16 Dec 2020 18:23:31 +0000
From: "Matthew Wilcox (Oracle)" <willy@...radead.org>
To: linux-fsdevel@...r.kernel.org, linux-mm@...ck.org
Cc: "Matthew Wilcox (Oracle)" <willy@...radead.org>,
linux-kernel@...r.kernel.org
Subject: [PATCH 21/25] mm: Convert wait_on_page_bit to wait_on_folio_bit
We must deal with folios here otherwise we'll get the wrong waitqueue
and fail to receive wakeups.
Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
fs/afs/write.c | 2 +-
include/linux/pagemap.h | 14 ++++++-----
mm/filemap.c | 54 ++++++++++++++++++-----------------------
mm/page-writeback.c | 7 +++---
4 files changed, 37 insertions(+), 40 deletions(-)
diff --git a/fs/afs/write.c b/fs/afs/write.c
index c9195fc67fd8..b58e7a69a464 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -852,7 +852,7 @@ vm_fault_t afs_page_mkwrite(struct vm_fault *vmf)
#endif
if (PageWriteback(vmf->page) &&
- wait_on_page_bit_killable(vmf->page, PG_writeback) < 0)
+ wait_on_folio_bit_killable(page_folio(vmf->page), PG_writeback) < 0)
return VM_FAULT_RETRY;
if (lock_page_killable(vmf->page) < 0)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 2283e58ebe32..ac4d3e2ac86c 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -717,8 +717,8 @@ static inline int lock_page_or_retry(struct page *page, struct mm_struct *mm,
* This is exported only for wait_on_page_locked/wait_on_page_writeback, etc.,
* and should not be used directly.
*/
-extern void wait_on_page_bit(struct page *page, int bit_nr);
-extern int wait_on_page_bit_killable(struct page *page, int bit_nr);
+extern void wait_on_folio_bit(struct folio *folio, int bit_nr);
+extern int wait_on_folio_bit_killable(struct folio *folio, int bit_nr);
/*
* Wait for a page to be unlocked.
@@ -729,15 +729,17 @@ extern int wait_on_page_bit_killable(struct page *page, int bit_nr);
*/
static inline void wait_on_page_locked(struct page *page)
{
- if (PageLocked(page))
- wait_on_page_bit(compound_head(page), PG_locked);
+ struct folio *folio = page_folio(page);
+ if (FolioLocked(folio))
+ wait_on_folio_bit(folio, PG_locked);
}
static inline int wait_on_page_locked_killable(struct page *page)
{
- if (!PageLocked(page))
+ struct folio *folio = page_folio(page);
+ if (!FolioLocked(folio))
return 0;
- return wait_on_page_bit_killable(compound_head(page), PG_locked);
+ return wait_on_folio_bit_killable(folio, PG_locked);
}
extern void put_and_wait_on_page_locked(struct page *page);
diff --git a/mm/filemap.c b/mm/filemap.c
index 3c5eb39452c3..a5925450ee13 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1075,7 +1075,7 @@ static int wake_page_function(wait_queue_entry_t *wait, unsigned mode, int sync,
*
* So update the flags atomically, and wake up the waiter
* afterwards to avoid any races. This store-release pairs
- * with the load-acquire in wait_on_page_bit_common().
+ * with the load-acquire in wait_on_folio_bit_common().
*/
smp_store_release(&wait->flags, flags | WQ_FLAG_WOKEN);
wake_up_state(wait->private, mode);
@@ -1156,7 +1156,7 @@ static void wake_up_folio(struct folio *folio, int bit)
}
/*
- * A choice of three behaviors for wait_on_page_bit_common():
+ * A choice of three behaviors for wait_on_folio_bit_common():
*/
enum behavior {
EXCLUSIVE, /* Hold ref to page and take the bit when woken, like
@@ -1190,9 +1190,10 @@ static inline bool trylock_page_bit_common(struct page *page, int bit_nr,
/* How many times do we accept lock stealing from under a waiter? */
int sysctl_page_lock_unfairness = 5;
-static inline int wait_on_page_bit_common(wait_queue_head_t *q,
- struct page *page, int bit_nr, int state, enum behavior behavior)
+static inline int wait_on_folio_bit_common(struct folio *folio, int bit_nr,
+ int state, enum behavior behavior)
{
+ wait_queue_head_t *q = page_waitqueue(&folio->page);
int unfairness = sysctl_page_lock_unfairness;
struct wait_page_queue wait_page;
wait_queue_entry_t *wait = &wait_page.wait;
@@ -1201,8 +1202,8 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
unsigned long pflags;
if (bit_nr == PG_locked &&
- !PageUptodate(page) && PageWorkingset(page)) {
- if (!PageSwapBacked(page)) {
+ !FolioUptodate(folio) && FolioWorkingset(folio)) {
+ if (!FolioSwapBacked(folio)) {
delayacct_thrashing_start();
delayacct = true;
}
@@ -1212,7 +1213,7 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
init_wait(wait);
wait->func = wake_page_function;
- wait_page.page = page;
+ wait_page.page = &folio->page;
wait_page.bit_nr = bit_nr;
repeat:
@@ -1227,7 +1228,7 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
* Do one last check whether we can get the
* page bit synchronously.
*
- * Do the SetPageWaiters() marking before that
+ * Do the SetFolioWaiters() marking before that
* to let any waker we _just_ missed know they
* need to wake us up (otherwise they'll never
* even go to the slow case that looks at the
@@ -1238,8 +1239,8 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
* lock to avoid races.
*/
spin_lock_irq(&q->lock);
- SetPageWaiters(page);
- if (!trylock_page_bit_common(page, bit_nr, wait))
+ SetFolioWaiters(folio);
+ if (!trylock_page_bit_common(&folio->page, bit_nr, wait))
__add_wait_queue_entry_tail(q, wait);
spin_unlock_irq(&q->lock);
@@ -1249,10 +1250,10 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
* see whether the page bit testing has already
* been done by the wake function.
*
- * We can drop our reference to the page.
+ * We can drop our reference to the folio.
*/
if (behavior == DROP)
- put_page(page);
+ put_folio(folio);
/*
* Note that until the "finish_wait()", or until
@@ -1289,7 +1290,7 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
*
* And if that fails, we'll have to retry this all.
*/
- if (unlikely(test_and_set_bit(bit_nr, &page->flags)))
+ if (unlikely(test_and_set_bit(bit_nr, folio_flags(folio))))
goto repeat;
wait->flags |= WQ_FLAG_DONE;
@@ -1329,19 +1330,17 @@ static inline int wait_on_page_bit_common(wait_queue_head_t *q,
return wait->flags & WQ_FLAG_WOKEN ? 0 : -EINTR;
}
-void wait_on_page_bit(struct page *page, int bit_nr)
+void wait_on_folio_bit(struct folio *folio, int bit_nr)
{
- wait_queue_head_t *q = page_waitqueue(page);
- wait_on_page_bit_common(q, page, bit_nr, TASK_UNINTERRUPTIBLE, SHARED);
+ wait_on_folio_bit_common(folio, bit_nr, TASK_UNINTERRUPTIBLE, SHARED);
}
-EXPORT_SYMBOL(wait_on_page_bit);
+EXPORT_SYMBOL(wait_on_folio_bit);
-int wait_on_page_bit_killable(struct page *page, int bit_nr)
+int wait_on_folio_bit_killable(struct folio *folio, int bit_nr)
{
- wait_queue_head_t *q = page_waitqueue(page);
- return wait_on_page_bit_common(q, page, bit_nr, TASK_KILLABLE, SHARED);
+ return wait_on_folio_bit_common(folio, bit_nr, TASK_KILLABLE, SHARED);
}
-EXPORT_SYMBOL(wait_on_page_bit_killable);
+EXPORT_SYMBOL(wait_on_folio_bit_killable);
static int __wait_on_page_locked_async(struct page *page,
struct wait_page_queue *wait, bool set)
@@ -1393,11 +1392,8 @@ static int wait_on_page_locked_async(struct page *page,
*/
void put_and_wait_on_page_locked(struct page *page)
{
- 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);
+ wait_on_folio_bit_common(page_folio(page), PG_locked,
+ TASK_UNINTERRUPTIBLE, DROP);
}
/**
@@ -1530,16 +1526,14 @@ EXPORT_SYMBOL_GPL(page_endio);
*/
void __lock_folio(struct folio *folio)
{
- wait_queue_head_t *q = page_waitqueue(&folio->page);
- wait_on_page_bit_common(q, &folio->page, PG_locked, TASK_UNINTERRUPTIBLE,
+ wait_on_folio_bit_common(folio, PG_locked, TASK_UNINTERRUPTIBLE,
EXCLUSIVE);
}
EXPORT_SYMBOL(__lock_folio);
int __lock_folio_killable(struct folio *folio)
{
- wait_queue_head_t *q = page_waitqueue(&folio->page);
- return wait_on_page_bit_common(q, &folio->page, PG_locked, TASK_KILLABLE,
+ return wait_on_folio_bit_common(folio, PG_locked, TASK_KILLABLE,
EXCLUSIVE);
}
EXPORT_SYMBOL_GPL(__lock_folio_killable);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 586042472ac9..500ed9afcec2 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2826,9 +2826,10 @@ EXPORT_SYMBOL(__test_set_page_writeback);
*/
void wait_on_page_writeback(struct page *page)
{
- if (PageWriteback(page)) {
- trace_wait_on_page_writeback(page, page_mapping(page));
- wait_on_page_bit(page, PG_writeback);
+ struct folio *folio = page_folio(page);
+ if (FolioWriteback(folio)) {
+ trace_wait_on_page_writeback(page, folio_mapping(folio));
+ wait_on_folio_bit(folio, PG_writeback);
}
}
EXPORT_SYMBOL_GPL(wait_on_page_writeback);
--
2.29.2
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