From f493af37abfb3c0ae0f62f628d2b20e9c32561c4 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 7 Jun 2018 13:47:33 +0200 Subject: nvme: don't rely on the changed namespace list log 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 Signed-off-by: Christoph Hellwig Reviewed-by: Keith Busch Reviewed-by: Hannes Reinecke --- 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 d6ca4598c027..dee8e71baf62 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3197,40 +3197,28 @@ 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) @@ -3246,9 +3234,8 @@ 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)) @@ -3263,7 +3250,6 @@ 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); -- cgit