linux-kernel - [PATCH] block2mtd: throttle writes by calling balance_dirty_pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 12 Dec 2012 19:32:15 +1100
From:	NeilBrown <neilb@...e.de>
To:	Joern Engel <joern@...ybastard.org>,
	David Woodhouse <dwmw2@...radead.org>
Cc:	linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: [PATCH] block2mtd: throttle writes by calling
 balance_dirty_pages_ratelimited.



If you create a block2mtd device that is larger than main memory,
and write to all of it, then lots of pages will be dirtied but
they will never be flushed out as nothing calls any variant of
balance_dirty_pages.

It would be nice to call set_page_dirty_balance(), but that isn't exported,
so just call balance_dirty_pages_ratelimited() directly.

Signed-off-by: NeilBrown <neilb@...e.de>

diff --git a/drivers/mtd/devices/block2mtd.c b/drivers/mtd/devices/block2mtd.c
index 681e2ee..2c3e8e7 100644
--- a/drivers/mtd/devices/block2mtd.c
+++ b/drivers/mtd/devices/block2mtd.c
@@ -62,6 +62,7 @@ static int _block2mtd_erase(struct block2mtd_dev *dev, loff_t to, size_t len)
 				memset(page_address(page), 0xff, PAGE_SIZE);
 				set_page_dirty(page);
 				unlock_page(page);
+				balance_dirty_pages_ratelimited(mapping);
 				break;
 			}
 
@@ -152,6 +153,7 @@ static int _block2mtd_write(struct block2mtd_dev *dev, const u_char *buf,
 			memcpy(page_address(page) + offset, buf, cpylen);
 			set_page_dirty(page);
 			unlock_page(page);
+			balance_dirty_pages_ratelimited(mapping);
 		}
 		page_cache_release(page);
 

Download attachment "signature.asc" of type "application/pgp-signature" (829 bytes)