openwrt/target/linux/generic/pending-6.6/452-block-add-support-for-notifications.patch
Christian Marangi f9a70a20c5
generic: backport BLOCK OF support patch
Backport BLOCK OF support patch merged upstream and refresh pending
BLOCK patches.

This is a new way to declare partition table for BLOCK device (eMMC
currently supported) with the use of DTS.

Current pending patch are adapted to not cause regression with current
downstream implementation of a similar functionality.

Also enable the new OF_PARTITION config by default.

Link: https://github.com/openwrt/openwrt/pull/16663
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
2024-10-11 17:18:40 +02:00

175 lines
5.6 KiB
Diff

From patchwork Tue Jul 30 19:26:42 2024
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X-Patchwork-Submitter: Daniel Golle <daniel@makrotopia.org>
X-Patchwork-Id: 13747817
Date: Tue, 30 Jul 2024 20:26:42 +0100
From: Daniel Golle <daniel@makrotopia.org>
To: Rob Herring <robh@kernel.org>, Krzysztof Kozlowski <krzk+dt@kernel.org>,
Conor Dooley <conor+dt@kernel.org>, Jens Axboe <axboe@kernel.dk>,
Daniel Golle <daniel@makrotopia.org>, Christian Brauner <brauner@kernel.org>,
Al Viro <viro@zeniv.linux.org.uk>, Li Lingfeng <lilingfeng3@huawei.com>,
Ming Lei <ming.lei@redhat.com>, Christian Heusel <christian@heusel.eu>,
=?utf-8?b?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>,
Felix Fietkau <nbd@nbd.name>, John Crispin <john@phrozen.org>,
Chad Monroe <chad.monroe@adtran.com>, Yangyu Chen <cyy@cyyself.name>,
Tianling Shen <cnsztl@immortalwrt.org>, Chuanhong Guo <gch981213@gmail.com>,
Chen Minqiang <ptpt52@gmail.com>, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-block@vger.kernel.org
Subject: [PATCH v5 3/4] block: add support for notifications
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<ca0022886e8f211a323a716653a1396a3bc91653.1722365899.git.daniel@makrotopia.org>
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Add notifier block to notify other subsystems about the addition or
removal of block devices.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
block/Kconfig | 6 +++
block/Makefile | 1 +
block/blk-notify.c | 87 ++++++++++++++++++++++++++++++++++++++++++
include/linux/blkdev.h | 11 ++++++
4 files changed, 105 insertions(+)
create mode 100644 block/blk-notify.c
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -208,6 +208,12 @@ config BLK_INLINE_ENCRYPTION_FALLBACK
by falling back to the kernel crypto API when inline
encryption hardware is not present.
+config BLOCK_NOTIFIERS
+ bool "Enable support for notifications in block layer"
+ help
+ Enable this option to provide notifiers for other subsystems
+ upon addition or removal of block devices.
+
source "block/partitions/Kconfig"
config BLK_MQ_PCI
--- a/block/Makefile
+++ b/block/Makefile
@@ -40,3 +40,4 @@ obj-$(CONFIG_BLK_INLINE_ENCRYPTION) += b
blk-crypto-sysfs.o
obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) += blk-crypto-fallback.o
obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED) += holder.o
+obj-$(CONFIG_BLOCK_NOTIFIERS) += blk-notify.o
--- /dev/null
+++ b/block/blk-notify.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Notifiers for addition and removal of block devices
+ *
+ * Copyright (c) 2024 Daniel Golle <daniel@makrotopia.org>
+ */
+
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/notifier.h>
+
+#include "blk.h"
+
+struct blk_device_list {
+ struct device *dev;
+ struct list_head list;
+};
+
+static RAW_NOTIFIER_HEAD(blk_notifier_list);
+static DEFINE_MUTEX(blk_notifier_lock);
+static LIST_HEAD(blk_devices);
+
+void blk_register_notify(struct notifier_block *nb)
+{
+ struct blk_device_list *existing_blkdev;
+
+ mutex_lock(&blk_notifier_lock);
+ raw_notifier_chain_register(&blk_notifier_list, nb);
+
+ list_for_each_entry(existing_blkdev, &blk_devices, list)
+ nb->notifier_call(nb, BLK_DEVICE_ADD, existing_blkdev->dev);
+
+ mutex_unlock(&blk_notifier_lock);
+}
+EXPORT_SYMBOL_GPL(blk_register_notify);
+
+void blk_unregister_notify(struct notifier_block *nb)
+{
+ mutex_lock(&blk_notifier_lock);
+ raw_notifier_chain_unregister(&blk_notifier_list, nb);
+ mutex_unlock(&blk_notifier_lock);
+}
+EXPORT_SYMBOL_GPL(blk_unregister_notify);
+
+static int blk_call_notifier_add(struct device *dev)
+{
+ struct blk_device_list *new_blkdev;
+
+ new_blkdev = kmalloc(sizeof(*new_blkdev), GFP_KERNEL);
+ if (!new_blkdev)
+ return -ENOMEM;
+
+ new_blkdev->dev = dev;
+ mutex_lock(&blk_notifier_lock);
+ list_add_tail(&new_blkdev->list, &blk_devices);
+ raw_notifier_call_chain(&blk_notifier_list, BLK_DEVICE_ADD, dev);
+ mutex_unlock(&blk_notifier_lock);
+ return 0;
+}
+
+static void blk_call_notifier_remove(struct device *dev)
+{
+ struct blk_device_list *old_blkdev, *tmp;
+
+ mutex_lock(&blk_notifier_lock);
+ list_for_each_entry_safe(old_blkdev, tmp, &blk_devices, list) {
+ if (old_blkdev->dev != dev)
+ continue;
+
+ list_del(&old_blkdev->list);
+ kfree(old_blkdev);
+ }
+ raw_notifier_call_chain(&blk_notifier_list, BLK_DEVICE_REMOVE, dev);
+ mutex_unlock(&blk_notifier_lock);
+}
+
+static struct class_interface blk_notifications_bus_interface __refdata = {
+ .class = &block_class,
+ .add_dev = &blk_call_notifier_add,
+ .remove_dev = &blk_call_notifier_remove,
+};
+
+static int __init blk_notifications_init(void)
+{
+ return class_interface_register(&blk_notifications_bus_interface);
+}
+device_initcall(blk_notifications_init);
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1567,4 +1567,15 @@ struct io_comp_batch {
#define DEFINE_IO_COMP_BATCH(name) struct io_comp_batch name = { }
+
+#define BLK_DEVICE_ADD 1
+#define BLK_DEVICE_REMOVE 2
+#if defined(CONFIG_BLOCK_NOTIFIERS)
+void blk_register_notify(struct notifier_block *nb);
+void blk_unregister_notify(struct notifier_block *nb);
+#else
+static inline void blk_register_notify(struct notifier_block *nb) { };
+static inline void blk_unregister_notify(struct notifier_block *nb) { };
+#endif
+
#endif /* _LINUX_BLKDEV_H */