[PATCH v2 3/4] nfs/blocklayout: Report only when /no/ device is found

[cel@kernel.org]

From: Chuck Lever <chuck.lever@oracle.com>

Since commit f931d8374cad ("nfs/blocklayout: refactor block device
opening"), an error is reported when no multi-path device is found.
But this isn't a fatal error if the subsequent device open is
successful. On systems without multi-path devices, this message
always appears whether there is a problem or not.

Instead, generate less system journal noise by reporting an error
only when both open attempts fail. The new error message is more
actionable since it indicates that there is a real configuration
issue to be addressed.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 fs/nfs/blocklayout/dev.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/blocklayout/dev.c b/fs/nfs/blocklayout/dev.c
index 83753a08a19d..568f685dee4b 100644
--- a/fs/nfs/blocklayout/dev.c
+++ b/fs/nfs/blocklayout/dev.c
@@ -338,7 +338,7 @@ bl_open_path(struct pnfs_block_volume *v, const char *prefix)
 	bdev_file = bdev_file_open_by_path(devname, BLK_OPEN_READ | BLK_OPEN_WRITE,
 					NULL, NULL);
 	if (IS_ERR(bdev_file)) {
-		pr_warn("pNFS: failed to open device %s (%ld)\n",
+		dprintk("failed to open device %s (%ld)\n",
 			devname, PTR_ERR(bdev_file));
 	}
 
@@ -367,8 +367,11 @@ bl_parse_scsi(struct nfs_server *server, struct pnfs_block_dev *d,
 	bdev_file = bl_open_path(v, "dm-uuid-mpath-0x");
 	if (IS_ERR(bdev_file))
 		bdev_file = bl_open_path(v, "wwn-0x");
-	if (IS_ERR(bdev_file))
+	if (IS_ERR(bdev_file)) {
+		pr_warn("pNFS: no device found for volume %*phN\n",
+			v->scsi.designator_len, v->scsi.designator);
 		return PTR_ERR(bdev_file);
+	}
 	d->bdev_file = bdev_file;
 
 	d->len = bdev_nr_bytes(file_bdev(d->bdev_file));
-- 
2.45.1