From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: Sun, 12 Dec 2021 12:16:06 +0000 (+0100)
Subject: 4.4-stable patches
X-Git-Tag: v4.4.295~46
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3b47bcbab44a94cad79960efd36b0011e00bcbcd;p=thirdparty%2Fkernel%2Fstable-queue.git

4.4-stable patches

added patches:
	mm-bdi-initialize-bdi_min_ratio-when-bdi-is-unregistered.patch
---

diff --git a/queue-4.4/mm-bdi-initialize-bdi_min_ratio-when-bdi-is-unregistered.patch b/queue-4.4/mm-bdi-initialize-bdi_min_ratio-when-bdi-is-unregistered.patch
new file mode 100644
index 00000000000..90f314c12e9
--- /dev/null
+++ b/queue-4.4/mm-bdi-initialize-bdi_min_ratio-when-bdi-is-unregistered.patch
@@ -0,0 +1,61 @@
+From 3c376dfafbf7a8ea0dea212d095ddd83e93280bb Mon Sep 17 00:00:00 2001
+From: Manjong Lee <mj0123.lee@samsung.com>
+Date: Fri, 10 Dec 2021 14:47:11 -0800
+Subject: mm: bdi: initialize bdi_min_ratio when bdi is unregistered
+
+From: Manjong Lee <mj0123.lee@samsung.com>
+
+commit 3c376dfafbf7a8ea0dea212d095ddd83e93280bb upstream.
+
+Initialize min_ratio if it is set during bdi unregistration.  This can
+prevent problems that may occur a when bdi is removed without resetting
+min_ratio.
+
+For example.
+1) insert external sdcard
+2) set external sdcard's min_ratio 70
+3) remove external sdcard without setting min_ratio 0
+4) insert external sdcard
+5) set external sdcard's min_ratio 70 << error occur(can't set)
+
+Because when an sdcard is removed, the present bdi_min_ratio value will
+remain.  Currently, the only way to reset bdi_min_ratio is to reboot.
+
+[akpm@linux-foundation.org: tweak comment and coding style]
+
+Link: https://lkml.kernel.org/r/20211021161942.5983-1-mj0123.lee@samsung.com
+Signed-off-by: Manjong Lee <mj0123.lee@samsung.com>
+Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+Cc: Changheun Lee <nanich.lee@samsung.com>
+Cc: Jens Axboe <axboe@kernel.dk>
+Cc: Christoph Hellwig <hch@infradead.org>
+Cc: Matthew Wilcox <willy@infradead.org>
+Cc: <seunghwan.hyun@samsung.com>
+Cc: <sookwan7.kim@samsung.com>
+Cc: <yt0928.kim@samsung.com>
+Cc: <junho89.kim@samsung.com>
+Cc: <jisoo2146.oh@samsung.com>
+Cc: <stable@vger.kernel.org>
+Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ mm/backing-dev.c |    7 +++++++
+ 1 file changed, 7 insertions(+)
+
+--- a/mm/backing-dev.c
++++ b/mm/backing-dev.c
+@@ -865,6 +865,13 @@ void bdi_unregister(struct backing_dev_i
+ 	wb_shutdown(&bdi->wb);
+ 	cgwb_bdi_destroy(bdi);
+ 
++	/*
++	 * If this BDI's min ratio has been set, use bdi_set_min_ratio() to
++	 * update the global bdi_min_ratio.
++	 */
++	if (bdi->min_ratio)
++		bdi_set_min_ratio(bdi, 0);
++
+ 	if (bdi->dev) {
+ 		bdi_debug_unregister(bdi);
+ 		device_unregister(bdi->dev);
diff --git a/queue-4.4/series b/queue-4.4/series
index 55bb82f373c..63e63843a24 100644
--- a/queue-4.4/series
+++ b/queue-4.4/series
@@ -7,3 +7,4 @@ hid-wacom-fix-problems-when-device-is-not-a-valid-usb-device.patch
 hid-check-for-valid-usb-device-for-many-hid-drivers.patch
 can-sja1000-fix-use-after-free-in-ems_pcmcia_add_card.patch
 nfc-fix-potential-null-pointer-deref-in-nfc_genl_dump_ses_done.patch
+mm-bdi-initialize-bdi_min_ratio-when-bdi-is-unregistered.patch