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authorChristoph Hellwig <hch@lst.de>2021-11-29 11:21:59 +0100
committerDan Williams <dan.j.williams@intel.com>2021-12-04 08:58:54 -0800
commitcd913c76f489def1a388e3a5b10df94948ede3f5 (patch)
treed144a96b23dd0ea4064702c2f5e06d4fe6258680 /drivers/dax
parent952da06375c8f3aa58474fff718d9ae8442531b9 (diff)
downloadlinux-cd913c76f489def1a388e3a5b10df94948ede3f5.tar.gz
dax: return the partition offset from fs_dax_get_by_bdev
Prepare for the removal of the block_device from the DAX I/O path by
returning the partition offset from fs_dax_get_by_bdev so that the file
systems have it at hand for use during I/O.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20211129102203.2243509-26-hch@lst.de
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dax')
-rw-r--r--drivers/dax/super.c9
1 files changed, 6 insertions, 3 deletions
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 45d931aefd06..e7152a6c4cc4 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -69,17 +69,20 @@ EXPORT_SYMBOL_GPL(dax_remove_host);
 /**
  * fs_dax_get_by_bdev() - temporary lookup mechanism for filesystem-dax
  * @bdev: block device to find a dax_device for
+ * @start_off: returns the byte offset into the dax_device that @bdev starts
  */
-struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev)
+struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev, u64 *start_off)
 {
 	struct dax_device *dax_dev;
+	u64 part_size;
 	int id;
 
 	if (!blk_queue_dax(bdev->bd_disk->queue))
 		return NULL;
 
-	if ((get_start_sect(bdev) * SECTOR_SIZE) % PAGE_SIZE ||
-	    (bdev_nr_sectors(bdev) * SECTOR_SIZE) % PAGE_SIZE) {
+	*start_off = get_start_sect(bdev) * SECTOR_SIZE;
+	part_size = bdev_nr_sectors(bdev) * SECTOR_SIZE;
+	if (*start_off % PAGE_SIZE || part_size % PAGE_SIZE) {
 		pr_info("%pg: error: unaligned partition for dax\n", bdev);
 		return NULL;
 	}