[PATCH v2 06/10] pmem: Implement ->corrupted_range() for pmem driver

[Shiyang Ruan <ruansy.fnst@xxxxxxxxxxxxxx>]

Obtain the superblock of a pmem disk, and call filesystem's
->corrupted_range() to handle the corrupted data.

Signed-off-by: Shiyang Ruan <ruansy.fnst@xxxxxxxxxxxxxx>
---
 block/genhd.c         |  6 ++++++
 drivers/nvdimm/pmem.c | 24 ++++++++++++++++++++++++
 include/linux/genhd.h |  1 +
 3 files changed, 31 insertions(+)

diff --git a/block/genhd.c b/block/genhd.c
index 419548e92d82..fd7cf03b65a8 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -936,6 +936,12 @@ struct block_device *bdget_disk(struct gendisk *disk, int partno)
 	return bdev;
 }
 
+struct block_device *bdget_disk_sector(struct gendisk *disk, sector_t sector)
+{
+	return disk_map_sector_rcu(disk, sector);
+}
+EXPORT_SYMBOL(bdget_disk_sector);
+
 /*
  * print a full list of all partitions - intended for places where the root
  * filesystem can't be mounted and thus to give the victim some idea of what
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index c9e4fb38f94a..501959947d48 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -253,6 +253,29 @@ static int pmem_rw_page(struct block_device *bdev, sector_t sector,
 	return blk_status_to_errno(rc);
 }
 
+static int pmem_corrupted_range(struct gendisk *disk, struct block_device *bdev,
+				loff_t disk_offset, size_t len, void *data)
+{
+	struct super_block *sb;
+	loff_t bdev_offset;
+	sector_t disk_sector = disk_offset >> SECTOR_SHIFT;
+	int rc = 0;
+
+	bdev = bdget_disk_sector(disk, disk_sector);
+	if (!bdev)
+		return -ENODEV;
+
+	bdev_offset = (disk_sector - get_start_sect(bdev)) << SECTOR_SHIFT;
+	sb = get_super(bdev);
+	if (sb && sb->s_op->corrupted_range) {
+		rc = sb->s_op->corrupted_range(sb, bdev, bdev_offset, len, data);
+		drop_super(sb);
+	}
+
+	bdput(bdev);
+	return rc;
+}
+
 /* see "strong" declaration in tools/testing/nvdimm/pmem-dax.c */
 __weak long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 		long nr_pages, void **kaddr, pfn_t *pfn)
@@ -281,6 +304,7 @@ static const struct block_device_operations pmem_fops = {
 	.owner =		THIS_MODULE,
 	.submit_bio =		pmem_submit_bio,
 	.rw_page =		pmem_rw_page,
+	.corrupted_range =	pmem_corrupted_range,
 };
 
 static int pmem_dax_zero_page_range(struct dax_device *dax_dev, pgoff_t pgoff,
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 809aaa32d53c..4da480798955 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -248,6 +248,7 @@ static inline void add_disk_no_queue_reg(struct gendisk *disk)
 
 extern void del_gendisk(struct gendisk *gp);
 extern struct block_device *bdget_disk(struct gendisk *disk, int partno);
+extern struct block_device *bdget_disk_sector(struct gendisk *disk, sector_t sector);
 
 extern void set_disk_ro(struct gendisk *disk, int flag);
 
-- 
2.30.0