[PATCH] lightnvm: invalid offset calculation for lba_shift

[Matias BjÃrling]

The ns->lba_shift assumes its value to be the logarithmic of the
LA size. A previous patch duplicated the lba_shift calculation into
lightnvm. It prematurely also subtracted a 512byte shift, which commonly
is applied per-command. The 512byte shift being subtracted twice led to
data loss when restoring the logical to physical mapping table from
device and when issuing I/O commands using rrpc.

Fix offset by removing the 512byte shift subtraction when calculating
lba_shift.

Fixes: b0b4e09c1ae7 "lightnvm: control life of nvm_dev in driver"
Reported-by: Javier GonzÃlez <javier@xxxxxxxxxxxx>
Signed-off-by: Matias BjÃrling <m@xxxxxxxxxxx>
---
 drivers/nvme/host/lightnvm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index f5e3011..5daf2f4 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -612,7 +612,7 @@ int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node,
 
 	ret = nvm_register(dev);
 
-	ns->lba_shift = ilog2(dev->sec_size) - 9;
+	ns->lba_shift = ilog2(dev->sec_size);
 
 	if (sysfs_create_group(&dev->dev.kobj, attrs))
 		pr_warn("%s: failed to create sysfs group for identification\n",
-- 
2.1.4