File 0030-nvme-ioctl-retrieve-log-pages-in-4k-chunks.patch of Package nvme-cli.10193

From aa76264a842c6fb3eca9fb32a2de4d44ed90db46 Mon Sep 17 00:00:00 2001
From: Hannes Reinecke <hare@suse.de>
Date: Thu, 20 Sep 2018 11:09:35 +0200
Subject: nvme-ioctl: retrieve log pages in 4k chunks

Git-commit: 465a4d5ab209bb20ea4b3ba808438747773edd2b
References: bsc#1076004

Some log pages increase with the scale of the subsystem, so the
overall size might be larger than the MDTS value for that controller.
In order to avoid having to pass in the MDTS value we should restrict
the transfer size to 4k and retrieve the log page in 4k chunks.

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
 nvme-ioctl.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/nvme-ioctl.c b/nvme-ioctl.c
index f267227..11e81d1 100644
--- a/nvme-ioctl.c
+++ b/nvme-ioctl.c
@@ -396,8 +396,30 @@ int nvme_get_log13(int fd, __u32 nsid, __u8 log_id, __u8 lsp, __u64 lpo,
 
 int nvme_get_log(int fd, __u32 nsid, __u8 log_id, __u32 data_len, void *data)
 {
-	return nvme_get_log13(fd, nsid, log_id, NVME_NO_LOG_LSP, NVME_NO_LOG_LPO,
-			      0, 0, data_len, data);
+	void *ptr = data;
+	__u32 offset = 0, xfer_len = data_len;
+	int ret;
+
+	/*
+	 * 4k is the smallest possible transfer unit, so by
+	 * restricting ourselves for 4k transfers we avoid having
+	 * to check the MDTS value of the controller.
+	 */
+	do {
+		xfer_len = data_len - offset;
+		if (xfer_len > 4096)
+			xfer_len = 4096;
+
+		ret = nvme_get_log13(fd, nsid, log_id, NVME_NO_LOG_LSP,
+				     offset, 0, false, xfer_len, ptr);
+		if (ret)
+			return ret;
+
+		offset += xfer_len;
+		ptr += xfer_len;
+	} while (offset < data_len);
+
+	return 0;
 }
 
 int nvme_fw_log(int fd, struct nvme_firmware_log_page *fw_log)
-- 
2.13.7