Hi Sergei,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on lwn/docs-next]
[also build test ERROR on linus/master v5.11-rc7 next-20210125]
[cannot apply to dm/for-next block/for-next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Sergei-Shtepa/block-layer-interposer/20210209-223704
base:   git://git.lwn.net/linux-2.6 docs-next
config: x86_64-rhel-8.3 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-15) 9.3.0
reproduce (this is a W=1 build):
        # https://github.com/0day-ci/linux/commit/2dbb264e739c9f95b90e4ea2a0cdb5d874628746
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Sergei-Shtepa/block-layer-interposer/20210209-223704
        git checkout 2dbb264e739c9f95b90e4ea2a0cdb5d874628746
        # save the attached .config to linux build tree
        make W=1 ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

Note: the linux-review/Sergei-Shtepa/block-layer-interposer/20210209-223704 HEAD a0be3a113742b603fe383ca9a97978f9815a8283 builds fine.
      It only hurts bisectibility.

All errors (new ones prefixed by >>):

   drivers/md/dm.c: In function 'open_table_device':
>> drivers/md/dm.c:1108:12: error: 'struct dm_dev' has no member named 'non_exclusive'
    1108 |  td->dm_dev.non_exclusive = non_exclusive;
         |            ^
   drivers/md/dm.c: In function 'dm_get_table_device':
>> drivers/md/dm.c:1157:12: error: too few arguments to function 'open_table_device'
    1157 |   if ((r = open_table_device(td, dev, md))) {
         |            ^~~~~~~~~~~~~~~~~
   drivers/md/dm.c:1079:12: note: declared here
    1079 | static int open_table_device(struct table_device *td, dev_t dev,
         |            ^~~~~~~~~~~~~~~~~


vim +1108 drivers/md/dm.c

  1075	
  1076	/*
  1077	 * Open a table device so we can use it as a map destination.
  1078	 */
  1079	static int open_table_device(struct table_device *td, dev_t dev,
  1080				     struct mapped_device *md, bool non_exclusive)
  1081	{
  1082		struct block_device *bdev;
  1083		int ret;
  1084	
  1085		BUG_ON(td->dm_dev.bdev);
  1086	
  1087		if (non_exclusive)
  1088			bdev = blkdev_get_by_dev(dev, td->dm_dev.mode, NULL);
  1089		else
  1090			bdev = blkdev_get_by_dev(dev, td->dm_dev.mode | FMODE_EXCL, _dm_claim_ptr);
  1091	
  1092		if (IS_ERR(bdev)) {
  1093			ret = PTR_ERR(bdev);
  1094			if (ret != -EBUSY)
  1095				return ret;
  1096		}
  1097	
  1098		if (!non_exclusive) {
  1099			ret = bd_link_disk_holder(bdev, dm_disk(md));
  1100			if (ret) {
  1101				blkdev_put(bdev, td->dm_dev.mode);
  1102				return ret;
  1103			}
  1104		}
  1105	
  1106		td->dm_dev.bdev = bdev;
  1107		td->dm_dev.dax_dev = dax_get_by_host(bdev->bd_disk->disk_name);
> 1108		td->dm_dev.non_exclusive = non_exclusive;
  1109		return 0;
  1110	}
  1111	
  1112	/*
  1113	 * Close a table device that we've been using.
  1114	 */
  1115	static void close_table_device(struct table_device *td, struct mapped_device *md)
  1116	{
  1117		if (!td->dm_dev.bdev)
  1118			return;
  1119	
  1120		bd_unlink_disk_holder(td->dm_dev.bdev, dm_disk(md));
  1121		blkdev_put(td->dm_dev.bdev, td->dm_dev.mode | FMODE_EXCL);
  1122		put_dax(td->dm_dev.dax_dev);
  1123		td->dm_dev.bdev = NULL;
  1124		td->dm_dev.dax_dev = NULL;
  1125	}
  1126	
  1127	static struct table_device *find_table_device(struct list_head *l, dev_t dev,
  1128						      fmode_t mode)
  1129	{
  1130		struct table_device *td;
  1131	
  1132		list_for_each_entry(td, l, list)
  1133			if (td->dm_dev.bdev->bd_dev == dev && td->dm_dev.mode == mode)
  1134				return td;
  1135	
  1136		return NULL;
  1137	}
  1138	
  1139	int dm_get_table_device(struct mapped_device *md, dev_t dev, fmode_t mode,
  1140				struct dm_dev **result)
  1141	{
  1142		int r;
  1143		struct table_device *td;
  1144	
  1145		mutex_lock(&md->table_devices_lock);
  1146		td = find_table_device(&md->table_devices, dev, mode);
  1147		if (!td) {
  1148			td = kmalloc_node(sizeof(*td), GFP_KERNEL, md->numa_node_id);
  1149			if (!td) {
  1150				mutex_unlock(&md->table_devices_lock);
  1151				return -ENOMEM;
  1152			}
  1153	
  1154			td->dm_dev.mode = mode;
  1155			td->dm_dev.bdev = NULL;
  1156	
> 1157			if ((r = open_table_device(td, dev, md))) {
  1158				mutex_unlock(&md->table_devices_lock);
  1159				kfree(td);
  1160				return r;
  1161			}
  1162	
  1163			format_dev_t(td->dm_dev.name, dev);
  1164	
  1165			refcount_set(&td->count, 1);
  1166			list_add(&td->list, &md->table_devices);
  1167		} else {
  1168			refcount_inc(&td->count);
  1169		}
  1170		mutex_unlock(&md->table_devices_lock);
  1171	
  1172		*result = &td->dm_dev;
  1173		return 0;
  1174	}
  1175	EXPORT_SYMBOL_GPL(dm_get_table_device);
  1176	

---
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