[PATCH 6/8][next] nvme: target: Avoid -Wflex-array-member-not-at-end warnings

["Gustavo A. R. Silva" <gustavoars@kernel.org>]

-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.

Change the type of the middle struct members currently causing trouble
from `struct bio` to `struct bio_hdr`.

We also use `container_of()` whenever we need to retrieve a pointer to
the flexible structure `struct bio`, through which we can access the
flexible-array member in it, if necessary.

With these changes fix 38 of the following warnings:

drivers/nvme/target/nvmet.h:455:49: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
drivers/nvme/target/nvmet.h:462:49: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
 drivers/nvme/target/nvmet.h    | 4 ++--
 drivers/nvme/target/passthru.c | 2 +-
 drivers/nvme/target/zns.c      | 2 +-
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 4be8d22d2d8d..13ee8026d3d8 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -452,14 +452,14 @@ struct nvmet_req {
 			struct work_struct      work;
 		} f;
 		struct {
-			struct bio		inline_bio;
+			struct bio_hdr		inline_bio;
 			struct request		*rq;
 			struct work_struct      work;
 			bool			use_workqueue;
 		} p;
 #ifdef CONFIG_BLK_DEV_ZONED
 		struct {
-			struct bio		inline_bio;
+			struct bio_hdr		inline_bio;
 			struct work_struct	zmgmt_work;
 		} z;
 #endif /* CONFIG_BLK_DEV_ZONED */
diff --git a/drivers/nvme/target/passthru.c b/drivers/nvme/target/passthru.c
index 26e2907ce8bb..bff52252ffb9 100644
--- a/drivers/nvme/target/passthru.c
+++ b/drivers/nvme/target/passthru.c
@@ -268,7 +268,7 @@ static int nvmet_passthru_map_sg(struct nvmet_req *req, struct request *rq)
 		return -EINVAL;
 
 	if (nvmet_use_inline_bvec(req)) {
-		bio = &req->p.inline_bio;
+		bio = container_of(&req->p.inline_bio, struct bio, __hdr);
 		bio_init(bio, NULL, req->inline_bvec,
 			 ARRAY_SIZE(req->inline_bvec), req_op(rq));
 	} else {
diff --git a/drivers/nvme/target/zns.c b/drivers/nvme/target/zns.c
index 29a60fabfcc8..afedbd984d39 100644
--- a/drivers/nvme/target/zns.c
+++ b/drivers/nvme/target/zns.c
@@ -570,7 +570,7 @@ void nvmet_bdev_execute_zone_append(struct nvmet_req *req)
 	}
 
 	if (nvmet_use_inline_bvec(req)) {
-		bio = &req->z.inline_bio;
+		bio = container_of(&req->z.inline_bio, struct bio, __hdr);
 		bio_init(bio, req->ns->bdev, req->inline_bvec,
 			 ARRAY_SIZE(req->inline_bvec), opf);
 	} else {
-- 
2.43.0