[PATCH 1/3] nvmet: add helper to set ns->blkshift value

[Chaitanya Kulkarni]

From: Chaitanya Kulkarni <kch at nvidia.com>

In order to support the block device in the buffered I/O mode, we use  
file backend. Calculating the blksize_shift value for the block device
backend is different from the file backend.  
 
Move existing code for calculating the namespace's blksize_shift value
into the helper for file backend. The last patch in this series will add
the code for block device blksize_shift calculation in the same helper.

Signed-off-by: Chaitanya Kulkarni <kch at nvidia.com>
---
 drivers/nvme/target/io-cmd-file.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c
index 6be6e59d273b..7aa4cdcb80ce 100644
--- a/drivers/nvme/target/io-cmd-file.c
+++ b/drivers/nvme/target/io-cmd-file.c
@@ -26,6 +26,16 @@ int nvmet_file_ns_revalidate(struct nvmet_ns *ns)
 	return ret;
 }
 
+static int nvmet_file_ns_set_blkshift(struct nvmet_ns *ns)
+{
+	/*
+	 * i_blkbits can be greater than the universally accepted upper bound,
+	 * so make sure we export a sane namespace lba_shift.
+	 */
+	ns->blksize_shift = min_t(u8, file_inode(ns->file)->i_blkbits, 12);
+	return 0;
+}
+
 void nvmet_file_ns_disable(struct nvmet_ns *ns)
 {
 	if (ns->file) {
@@ -57,17 +67,14 @@ int nvmet_file_ns_enable(struct nvmet_ns *ns)
 		return ret;
 	}
 
+	ret = nvmet_file_ns_set_blkshift(ns);
+	if (ret)
+		return ret;
+
 	ret = nvmet_file_ns_revalidate(ns);
 	if (ret)
 		goto err;
 
-	/*
-	 * i_blkbits can be greater than the universally accepted upper bound,
-	 * so make sure we export a sane namespace lba_shift.
-	 */
-	ns->blksize_shift = min_t(u8,
-			file_inode(ns->file)->i_blkbits, 12);
-
 	ns->bvec_cache = kmem_cache_create("nvmet-bvec",
 			NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec),
 			0, SLAB_HWCACHE_ALIGN, NULL);
-- 
2.29.0