[PATCH] nvme-multipath: use vmalloc for ANA log buffer

[Daniel Wagner]

From: Hannes Reinecke <hare at suse.de>

The ANA log buffer can get really large, as it depends on the
controller configuration. So to avoid an out-of-memory issue
during scanning use kvmalloc() instead of the kmalloc().

Signed-off-by: Hannes Reinecke <hare at suse.de>
Tested-by: Daniel Wagner <dwagner at suse.de>
Signed-off-by: Daniel Wagner <dwagner at suse.de>
---

As discussed in [1] switch the ana buffer memory type to
kvmalloc. I've done some simple testing but also got positive feedback
from our partner who observerd order 7 allocation with kmalloc.

This patch is cut against nvme-5.18. Let me know, if it should be
again something else.

[1] https://lore.kernel.org/linux-nvme/20220207100005.34404-1-hare@suse.de/

 drivers/nvme/host/multipath.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index f8bf6606eb2f..3ddc1ba66f0d 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -5,6 +5,7 @@
 
 #include <linux/backing-dev.h>
 #include <linux/moduleparam.h>
+#include <linux/vmalloc.h>
 #include <trace/events/block.h>
 #include "nvme.h"
 
@@ -898,7 +899,7 @@ int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 	if (ana_log_size > ctrl->ana_log_size) {
 		nvme_mpath_stop(ctrl);
 		nvme_mpath_uninit(ctrl);
-		ctrl->ana_log_buf = kmalloc(ana_log_size, GFP_KERNEL);
+		ctrl->ana_log_buf = kvmalloc(ana_log_size, GFP_KERNEL);
 		if (!ctrl->ana_log_buf)
 			return -ENOMEM;
 	}
@@ -915,7 +916,7 @@ int nvme_mpath_init_identify(struct nvme_ctrl *ctrl, struct nvme_id_ctrl *id)
 
 void nvme_mpath_uninit(struct nvme_ctrl *ctrl)
 {
-	kfree(ctrl->ana_log_buf);
+	kvfree(ctrl->ana_log_buf);
 	ctrl->ana_log_buf = NULL;
 	ctrl->ana_log_size = 0;
 }
-- 
2.29.2