[PATCH 01/17] nvme: introduce namespace features flag

[Max Gurtovoy <maxg@xxxxxxxxxxxx>]

From: Israel Rukshin <israelr@xxxxxxxxxxxx>

Centralize all the metadata checks to one place and make the code more
readable. Introduce a new enum nvme_ns_features for that matter.
The features flag description:
 - NVME_NS_EXT_LBAS - NVMe namespace supports extended LBA format.
 - NVME_NS_MD_HOST_SUPPORTED - NVMe namespace supports getting metadata
   from host's block layer.
 - NVME_NS_MD_CTRL_SUPPORTED - NVMe namespace supports metadata actions
   by the controller (generate/strip).

Suggested-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
Signed-off-by: Israel Rukshin <israelr@xxxxxxxxxxxx>
---
 drivers/nvme/host/core.c | 42 ++++++++++++++++++++++++++++--------------
 drivers/nvme/host/nvme.h |  8 +++++++-
 2 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 1cab3c6..f3a184f 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -203,11 +203,6 @@ static void nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl)
 	nvme_put_ctrl(ctrl);
 }
 
-static inline bool nvme_ns_has_pi(struct nvme_ns *ns)
-{
-	return ns->pi_type && ns->ms == sizeof(struct t10_pi_tuple);
-}
-
 static blk_status_t nvme_error_status(u16 status)
 {
 	switch (status & 0x7ff) {
@@ -706,7 +701,8 @@ static inline blk_status_t nvme_setup_rw(struct nvme_ns *ns,
 		 * namespace capacity to zero to prevent any I/O.
 		 */
 		if (!blk_integrity_rq(req)) {
-			if (WARN_ON_ONCE(!nvme_ns_has_pi(ns)))
+			if (WARN_ON_ONCE(!(ns->features &
+					   NVME_NS_MD_CTRL_SUPPORTED)))
 				return BLK_STS_NOTSUPP;
 			control |= NVME_RW_PRINFO_PRACT;
 		}
@@ -1277,7 +1273,7 @@ static int nvme_submit_io(struct nvme_ns *ns, struct nvme_user_io __user *uio)
 	meta_len = (io.nblocks + 1) * ns->ms;
 	metadata = (void __user *)(uintptr_t)io.metadata;
 
-	if (ns->ext) {
+	if (ns->features & NVME_NS_EXT_LBAS) {
 		length += meta_len;
 		meta_len = 0;
 	} else if (meta_len) {
@@ -1837,11 +1833,12 @@ static void nvme_update_disk_info(struct gendisk *disk,
 	blk_queue_io_min(disk->queue, phys_bs);
 	blk_queue_io_opt(disk->queue, io_opt);
 
-	if (ns->ms && !ns->ext &&
-	    (ns->ctrl->ops->flags & NVME_F_METADATA_SUPPORTED))
+	if (ns->features & NVME_NS_MD_HOST_SUPPORTED)
 		nvme_init_integrity(disk, ns->ms, ns->pi_type);
-	if ((ns->ms && !nvme_ns_has_pi(ns) && !blk_get_integrity(disk)) ||
-	    ns->lba_shift > PAGE_SHIFT)
+
+	if ((ns->ms && !(ns->features & NVME_NS_MD_CTRL_SUPPORTED) &&
+	     !(ns->features & NVME_NS_MD_HOST_SUPPORTED) &&
+	     !blk_get_integrity(disk)) || ns->lba_shift > PAGE_SHIFT)
 		capacity = 0;
 
 	set_capacity(disk, capacity);
@@ -1870,12 +1867,29 @@ static void __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id)
 		ns->lba_shift = 9;
 	ns->noiob = le16_to_cpu(id->noiob);
 	ns->ms = le16_to_cpu(id->lbaf[id->flbas & NVME_NS_FLBAS_LBA_MASK].ms);
-	ns->ext = ns->ms && (id->flbas & NVME_NS_FLBAS_META_EXT);
+	ns->features = 0;
 	/* the PI implementation requires metadata equal t10 pi tuple size */
-	if (ns->ms == sizeof(struct t10_pi_tuple))
+	if (ns->ms == sizeof(struct t10_pi_tuple)) {
 		ns->pi_type = id->dps & NVME_NS_DPS_PI_MASK;
-	else
+		if (ns->pi_type)
+			ns->features |= NVME_NS_MD_CTRL_SUPPORTED;
+	} else {
 		ns->pi_type = 0;
+	}
+
+	if (ns->ms) {
+		if (id->flbas & NVME_NS_FLBAS_META_EXT)
+			ns->features |= NVME_NS_EXT_LBAS;
+
+		/*
+		 * For PCI, Extended logical block will be generated by the
+		 * controller.
+		 */
+		if (ns->ctrl->ops->flags & NVME_F_METADATA_SUPPORTED) {
+			if (!(ns->features & NVME_NS_EXT_LBAS))
+				ns->features |= NVME_NS_MD_HOST_SUPPORTED;
+		}
+	}
 
 	if (ns->noiob)
 		nvme_set_chunk_size(ns);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 2e04a36..83296d0 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -363,6 +363,12 @@ struct nvme_ns_head {
 #endif
 };
 
+enum nvme_ns_features {
+	NVME_NS_EXT_LBAS = 1 << 0,
+	NVME_NS_MD_HOST_SUPPORTED = 1 << 1,
+	NVME_NS_MD_CTRL_SUPPORTED = 1 << 2,
+};
+
 struct nvme_ns {
 	struct list_head list;
 
@@ -382,8 +388,8 @@ struct nvme_ns {
 	u16 ms;
 	u16 sgs;
 	u32 sws;
-	bool ext;
 	u8 pi_type;
+	unsigned long features;
 	unsigned long flags;
 #define NVME_NS_REMOVING	0
 #define NVME_NS_DEAD     	1
-- 
1.8.3.1