Received-SPF: pass (google.com: domain of linux-kernel+bounces-178483-linux.lists.archive=gmail.com@vger.kernel.org designates 139.178.88.99 as permitted sender) client-ip=139.178.88.99;
From: Yang Yang <yang.yang@vivo.com>
To: Alasdair Kergon <agk@redhat.com>,
	Mike Snitzer <snitzer@kernel.org>,
	Mikulas Patocka <mpatocka@redhat.com>,
	dm-devel@lists.linux.dev,
	linux-kernel@vger.kernel.org
Cc: Yang Yang <yang.yang@vivo.com>
Subject: [PATCH 3/5] dm: support retrieving struct dm_target from struct dm_dev
Date: Tue, 14 May 2024 17:04:42 +0800
Message-Id: <20240514090445.2847-4-yang.yang@vivo.com>
In-Reply-To: <20240514090445.2847-1-yang.yang@vivo.com>
References: <20240514090445.2847-1-yang.yang@vivo.com>
Content-Transfer-Encoding: 8bit
Content-Type: text/plain
Precedence: bulk
MIME-Version: 1.0
X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-MessageData-0:
	=?us-ascii?Q?/FcNCiaJvIKCnhWD2Q6hw1ZgCwTOec5ylyaa/3SXMy4Z+vFSMVEbtRD6vyfl?=
 =?us-ascii?Q?RiA9ZxpL7+HjCOr6QqPRDF6isf2q1xPTyTq7b3WufR1cfOPBmIqP+b5dQ4Yz?=
 =?us-ascii?Q?fi/96W8bCfJlT7/e+O+Z/GetVZTpKajkdCcq1eYhBKyeHcMwniwIgL0yE186?=
 =?us-ascii?Q?Nvq1FtynU30744idB/b3oMtz4R53/yuvs5P/uW2lkywXkV8eu5xnST8O6MBJ?=
 =?us-ascii?Q?fi+J6cE1e1cV1gBvzAKQF7tLAJ6cbAUwrin1y/c92s8EBRC9CQgOcsihQzWB?=
 =?us-ascii?Q?q2/jZlkOzfcXco4Gz8T2TSDs8NExAVGv2jUnL56Or/hY+rNNRnxj9SU56HTG?=
 =?us-ascii?Q?lsZBUGMcrHw9QB/MgwivY2CsxmsAjIlahoxzT7+/y/wH5aWcMgfFqvxTCain?=
 =?us-ascii?Q?8OwWa7vQm7ckulj/KbPG6WwtWGalCXe6uYsM08u4nWegr6OFJ8qlht7DHY2j?=
 =?us-ascii?Q?XwaK0AlzvCWldMQoVa04nFcHrSKUptW1Ei4uY9XzQHucDhXb4sV1g/cAFcVk?=
 =?us-ascii?Q?X+RVDzeXqNQbNE0Fc2YAdjnscH2xn8R97ggL9aJElpreU87CiBQxturNb8mF?=
 =?us-ascii?Q?SMfLZZfLN8bk1SuJn78hLtPv+8SiBJSQOBWk5Z25wH5GRh4TQ0YYIIfmQGus?=
 =?us-ascii?Q?rscMNDLhMt3oIW+lyXzlDreOAC0Qbk7Q/cj3KxDn2ygWY3ZQkGgXl6ssG2h7?=
 =?us-ascii?Q?Zk1KBLNVlFvVIS5zhrda3ZTyOZKhg6L5kQYBpVr+WmGtdxLDpqadzTR+DrQA?=
 =?us-ascii?Q?8ku5D4aN5IUFwmb4vvA4Hqytyi9DivUA6h2PO0WUtTfQJTmNxRfaoWCxGn+i?=
 =?us-ascii?Q?HT37gXgKtGiBWWPv81QRT8pk0ZHgvnOdi6lsy9+B0pknrPRuZqRHKHWqmlDE?=
 =?us-ascii?Q?jQ0s7gPpiJfrL7EVx/hh4r/PaQZ7qsw70svtxv19GkkCVPlJ8wYh9daMR2Hc?=
 =?us-ascii?Q?l/yWtPZ/Rkar3Nl2I6kfoOYV+RrbbCo+XPCAX9N1v4TJWp7dkeT0lX3N3VQe?=
 =?us-ascii?Q?fENkVz1D1V4fMyEkkd5fgKAHXAUc5S0gN6c9p7TqVioyMbzVhF0Wzf0s+X4C?=
 =?us-ascii?Q?Oo68T3Uo5p3ehuFjUCMEENjip60XyIYWHvzToEBWVC1gBwMjdiACCAEyZCoS?=
 =?us-ascii?Q?K47RL8UzSvCRV6Si/M+3fsQ7wc8UxiXzlMBKuTCHIeTVzXAOXaC8vJfRShne?=
 =?us-ascii?Q?rTLAsfI3KMD5RAq+X/tew2uvBuCKMnz6Obp+GC90/pMcBkwFej8uLtkroV+y?=
 =?us-ascii?Q?HLNQmABxa0SWqTOWy7vO70X02GwhDFtMe+mXoMeFg7IKUOIybjTh/c+nNAcV?=
 =?us-ascii?Q?6871sxJ4fLvPVuOifJx2Ncox/Eaxrqa4q70vHAy24r+JuKNRagKg9bN77Xsg?=
 =?us-ascii?Q?n1SDzQmVNT2H2zw1bmsDC9gIsBFgQbWaf31mSff76i8D8iyjmYz8PQDEI13z?=
 =?us-ascii?Q?BFtEkq6g+A2JH0lPGKLgTNUTbQIH042d3qNMNsyHFoqDvZcbAz1lyP4bhm7U?=
 =?us-ascii?Q?JUM4EzLYq5K53wcYYvOjhlq29wMJNWj49tvFwrPxgMDIi68BLpVG5Y/oLa7x?=
 =?us-ascii?Q?S2ZX2B+F4nPcbzTtGrbhr9Hlj8snHvwG63DsoAML?=
X-OriginatorOrg: vivo.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 01a95b6c-f61d-403f-a869-08dc73f51033
X-MS-Exchange-CrossTenant-AuthSource: SEYPR06MB6398.apcprd06.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Internal
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 14 May 2024 09:05:55.7555
 (UTC)
X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted
X-MS-Exchange-CrossTenant-Id: 923e42dc-48d5-4cbe-b582-1a797a6412ed
X-MS-Exchange-CrossTenant-MailboxType: HOSTED
X-MS-Exchange-CrossTenant-UserPrincipalName: 4LYvc197lNDsOIbnMV29w5KgiU1/5d4h3rpsSiVNJ6HUW4RQEfnUaqpNiZzpCPy7LcvbCsKsIQTKneQnnb4dXw==
X-MS-Exchange-Transport-CrossTenantHeadersStamped: PUZPR06MB6102

Add a list to the struct dm_dev structure to store the associated
targets, while also allowing differentiation between different target
types.

Signed-off-by: Yang Yang <yang.yang@vivo.com>
---
 drivers/md/dm-table.c         | 36 +++++++++++++++++++++++++++++++++++
 include/linux/device-mapper.h |  3 +++
 2 files changed, 39 insertions(+)

diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index bd68af10afed..f6554590b7af 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -741,6 +741,8 @@ int dm_table_add_target(struct dm_table *t, const char *type,
 	if (ti->flush_pass_around == 0)
 		t->flush_pass_around = 0;
 
+	INIT_LIST_HEAD(&ti->list);
+
 	return 0;
 
  bad:
@@ -2134,6 +2136,25 @@ void dm_table_postsuspend_targets(struct dm_table *t)
 	suspend_targets(t, POSTSUSPEND);
 }
 
+static int dm_link_dev_to_target(struct dm_target *ti, struct dm_dev *dev,
+		sector_t start, sector_t len, void *data)
+{
+	struct list_head *targets = &dev->targets;
+	struct dm_target *pti;
+
+	if (!list_empty(targets)) {
+		list_for_each_entry(pti, targets, list) {
+			if (pti->type == ti->type)
+				return 0;
+		}
+	}
+
+	if (list_empty(&ti->list))
+		list_add_tail(&ti->list, targets);
+
+	return 0;
+}
+
 int dm_table_resume_targets(struct dm_table *t)
 {
 	unsigned int i;
@@ -2162,6 +2183,21 @@ int dm_table_resume_targets(struct dm_table *t)
 			ti->type->resume(ti);
 	}
 
+	if (t->flush_pass_around) {
+		struct list_head *devices = &t->devices;
+		struct dm_dev_internal *dd;
+
+		list_for_each_entry(dd, devices, list)
+			INIT_LIST_HEAD(&dd->dm_dev->targets);
+
+		for (i = 0; i < t->num_targets; i++) {
+			struct dm_target *ti = dm_table_get_target(t, i);
+
+			if (ti->type->iterate_devices)
+				ti->type->iterate_devices(ti, dm_link_dev_to_target, NULL);
+		}
+	}
+
 	return 0;
 }
 
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 0893ff8c01b6..19e03f9b2589 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -169,6 +169,7 @@ struct dm_dev {
 	struct dax_device *dax_dev;
 	blk_mode_t mode;
 	char name[16];
+	struct list_head targets;
 };
 
 /*
@@ -298,6 +299,8 @@ struct dm_target {
 	struct dm_table *table;
 	struct target_type *type;
 
+	struct list_head list;
+
 	/* target limits */
 	sector_t begin;
 	sector_t len;
-- 
2.34.1