From: Christoph Hellwig <hch@lst.de>
Date: Thu, 7 Jun 2018 13:47:33 +0200
Subject: [PATCH] nvme: don't rely on the changed namespace list log
References: bsc#1054245
Git-commit: f493af37abfb3c0ae0f62f628d2b20e9c32561c4
Patch-mainline: v4.18-rc1
Don't optimize our namespace rescan based on the changed namespace list
log page as userspace might have changed the content through reading
it.
Suggested-by: Keith Busch <keith.busch@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@linux.intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/nvme/host/core.c | 36 +++++++++++-------------------------
1 file changed, 11 insertions(+), 25 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 33793d3eaed6..0c23ff3d831c 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3184,40 +3184,28 @@ static void nvme_scan_ns_sequential(struct nvme_ctrl *ctrl, unsigned nn)
nvme_remove_invalid_namespaces(ctrl, nn);
}
-static bool nvme_scan_changed_ns_log(struct nvme_ctrl *ctrl)
+static void nvme_clear_changed_ns_log(struct nvme_ctrl *ctrl)
{
size_t log_size = NVME_MAX_CHANGED_NAMESPACES * sizeof(__le32);
__le32 *log;
- int error, i;
- bool ret = false;
+ int error;
log = kzalloc(log_size, GFP_KERNEL);
if (!log)
- return false;
+ return;
+ /*
+ * We need to read the log to clear the AEN, but we don't want to rely
+ * on it for the changed namespace information as userspace could have
+ * raced with us in reading the log page, which could cause us to miss
+ * updates.
+ */
error = nvme_get_log(ctrl, NVME_LOG_CHANGED_NS, log, log_size);
- if (error) {
+ if (error)
dev_warn(ctrl->device,
"reading changed ns log failed: %d\n", error);
- goto out_free_log;
- }
-
- if (log[0] == cpu_to_le32(0xffffffff))
- goto out_free_log;
- for (i = 0; i < NVME_MAX_CHANGED_NAMESPACES; i++) {
- u32 nsid = le32_to_cpu(log[i]);
-
- if (nsid == 0)
- break;
- dev_info(ctrl->device, "rescanning namespace %d.\n", nsid);
- nvme_validate_ns(ctrl, nsid);
- }
- ret = true;
-
-out_free_log:
kfree(log);
- return ret;
}
static void nvme_scan_work(struct work_struct *work)
@@ -3233,9 +3221,8 @@ static void nvme_scan_work(struct work_struct *work)
WARN_ON_ONCE(!ctrl->tagset);
if (test_and_clear_bit(NVME_AER_NOTICE_NS_CHANGED, &ctrl->events)) {
- if (nvme_scan_changed_ns_log(ctrl))
- goto out_sort_namespaces;
dev_info(ctrl->device, "rescanning namespaces.\n");
+ nvme_clear_changed_ns_log(ctrl);
}
if (nvme_identify_ctrl(ctrl, &id))
@@ -3250,7 +3237,6 @@ static void nvme_scan_work(struct work_struct *work)
nvme_scan_ns_sequential(ctrl, nn);
out_free_id:
kfree(id);
-out_sort_namespaces:
down_write(&ctrl->namespaces_rwsem);
list_sort(NULL, &ctrl->namespaces, ns_cmp);
up_write(&ctrl->namespaces_rwsem);
--
2.12.3