NVMe: Namespace IDs are unsigned

The 'Number of Namespaces' read from the device was being treated as
signed, which would cause us to not scan any namespaces for a device
with more than 2 billion namespaces.  That led to noticing that the
namespace ID was also being treated as signed, which could lead to the
result from NVME_IOCTL_ID being treated as an error code.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>

2 files changed, 6 insertions, 3 deletions

diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
index 07d527c66eb4..56d1fa472d06 100644
--- a/drivers/block/nvme-core.c
+++ b/drivers/block/nvme-core.c
@@ -36,6 +36,7 @@
 #include <linux/moduleparam.h>
 #include <linux/pci.h>
 #include <linux/poison.h>
+#include <linux/ptrace.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/types.h>
@@ -1486,6 +1487,7 @@ static int nvme_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
 
         switch (cmd) {
         case NVME_IOCTL_ID:
+                force_successful_syscall_return();
                 return ns->ns_id;
         case NVME_IOCTL_ADMIN_CMD:
                 return nvme_user_admin_cmd(ns->dev, (void __user *)arg);
@@ -1588,7 +1590,7 @@ static void nvme_config_discard(struct nvme_ns *ns)
         queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, ns->queue);
 }
 
-static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, int nsid,
+static struct nvme_ns *nvme_alloc_ns(struct nvme_dev *dev, unsigned nsid,
                         struct nvme_id_ns *id, struct nvme_lba_range_type *rt)
 {
         struct nvme_ns *ns;
@@ -1768,7 +1770,8 @@ static void nvme_free_queues(struct nvme_dev *dev)
  */
 static int nvme_dev_add(struct nvme_dev *dev)
 {
-        int res, nn, i;
+        int res;
+        unsigned nn, i;
         struct nvme_ns *ns;
         struct nvme_id_ctrl *ctrl;
         struct nvme_id_ns *id_ns;
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 8d0041513e1a..3403c8f06fa0 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -104,7 +104,7 @@ struct nvme_ns {
         struct request_queue *queue;
         struct gendisk *disk;
 
-        int ns_id;
+        unsigned ns_id;
         int lba_shift;
         int ms;
         u64 mode_select_num_blocks;