Commit ab22590f authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Zizhi Wo
Browse files

filemap: remove use of wait bookmarks 

mainline inclusion
from mainline-v6.7-rc1
commit b0b598ee08f9759b70971e297cf7ddd3eaaa5245
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I93R1D
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b0b598ee08f9759b70971e297cf7ddd3eaaa5245

--------------------------------

The original problem of the overly long list of waiters on a locked page
was solved properly by commit 9a1ea439 ("mm:
put_and_wait_on_page_locked() while page is migrated").  In the meantime,
using bookmarks for the writeback bit can cause livelocks, so we need to
stop using them.

Link: https://lkml.kernel.org/r/20231010035829.544242-1-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Bin Lai <sclaibin@gmail.com>
Cc: Benjamin Segall <bsegall@google.com>
Cc: Daniel Bristot de Oliveira <bristot@redhat.com>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>

Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarZizhi Wo <wozizhi@huawei.com>

Conflicts:
	mm/filemap.c
parent 2644e97c

mm/filemap.c

+1 −20
Original line number Diff line number Diff line
@@ -1095,32 +1095,13 @@ static void wake_up_page_bit(struct page *page, int bit_nr) 
	wait_queue_head_t *q = page_waitqueue(page);

	struct wait_page_key key;

	unsigned long flags;

	wait_queue_entry_t bookmark;



	key.page = page;

	key.bit_nr = bit_nr;

	key.page_match = 0;



	bookmark.flags = 0;

	bookmark.private = NULL;

	bookmark.func = NULL;

	INIT_LIST_HEAD(&bookmark.entry);



	spin_lock_irqsave(&q->lock, flags);

	__wake_up_locked_key_bookmark(q, TASK_NORMAL, &key, &bookmark);



	while (bookmark.flags & WQ_FLAG_BOOKMARK) {

		/*

		 * Take a breather from holding the lock,

		 * allow pages that finish wake up asynchronously

		 * to acquire the lock and remove themselves

		 * from wait queue

		 */

		spin_unlock_irqrestore(&q->lock, flags);

		cpu_relax();

		spin_lock_irqsave(&q->lock, flags);

		__wake_up_locked_key_bookmark(q, TASK_NORMAL, &key, &bookmark);

	}

	__wake_up_locked_key(q, TASK_NORMAL, &key);



	/*

	 * It is possible for other pages to have collided on the waitqueue