From 4005f28d25cbd3d4f85529a31e46a0b78e293082 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 4 Apr 2020 10:31:35 +0200 Subject: [PATCH] nvme: avoid an Identify Controller command for each namespace scan The namespace lists are 0-terminated, so we don't really need the NN value execept for the legacy sequential scan. Signed-off-by: Christoph Hellwig Reviewed-by: Keith Busch Signed-off-by: Jens Axboe --- drivers/nvme/host/core.c | 40 ++++++++++++++++++---------------------- 1 file changed, 18 insertions(+), 22 deletions(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 42102b81d540..15b63426a113 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3740,12 +3740,11 @@ static void nvme_remove_invalid_namespaces(struct nvme_ctrl *ctrl, } -static int nvme_scan_ns_list(struct nvme_ctrl *ctrl, unsigned nn) +static int nvme_scan_ns_list(struct nvme_ctrl *ctrl) { __le32 *ns_list; - unsigned i, j, nsid, prev = 0; - unsigned num_lists = DIV_ROUND_UP_ULL((u64)nn, 1024); - int ret = 0; + u32 prev = 0; + int ret = 0, i; if (nvme_ctrl_limited_cns(ctrl)) return -EOPNOTSUPP; @@ -3754,22 +3753,20 @@ static int nvme_scan_ns_list(struct nvme_ctrl *ctrl, unsigned nn) if (!ns_list) return -ENOMEM; - for (i = 0; i < num_lists; i++) { + for (;;) { ret = nvme_identify_ns_list(ctrl, prev, ns_list); if (ret) goto free; - for (j = 0; j < min(nn, 1024U); j++) { - nsid = le32_to_cpu(ns_list[j]); - if (!nsid) - goto out; + for (i = 0; i < 1024; i++) { + u32 nsid = le32_to_cpu(ns_list[i]); + if (!nsid) /* end of the list? */ + goto out; nvme_validate_ns(ctrl, nsid); - while (++prev < nsid) nvme_ns_remove_by_nsid(ctrl, prev); } - nn -= j; } out: nvme_remove_invalid_namespaces(ctrl, prev); @@ -3778,9 +3775,15 @@ static int nvme_scan_ns_list(struct nvme_ctrl *ctrl, unsigned nn) return ret; } -static void nvme_scan_ns_sequential(struct nvme_ctrl *ctrl, unsigned nn) +static void nvme_scan_ns_sequential(struct nvme_ctrl *ctrl) { - unsigned i; + struct nvme_id_ctrl *id; + u32 nn, i; + + if (nvme_identify_ctrl(ctrl, &id)) + return; + nn = le32_to_cpu(id->nn); + kfree(id); for (i = 1; i <= nn; i++) nvme_validate_ns(ctrl, i); @@ -3817,8 +3820,6 @@ static void nvme_scan_work(struct work_struct *work) { struct nvme_ctrl *ctrl = container_of(work, struct nvme_ctrl, scan_work); - struct nvme_id_ctrl *id; - unsigned nn; /* No tagset on a live ctrl means IO queues could not created */ if (ctrl->state != NVME_CTRL_LIVE || !ctrl->tagset) @@ -3829,14 +3830,9 @@ static void nvme_scan_work(struct work_struct *work) nvme_clear_changed_ns_log(ctrl); } - if (nvme_identify_ctrl(ctrl, &id)) - return; - nn = le32_to_cpu(id->nn); - kfree(id); - mutex_lock(&ctrl->scan_lock); - if (nvme_scan_ns_list(ctrl, nn) != 0) - nvme_scan_ns_sequential(ctrl, nn); + if (nvme_scan_ns_list(ctrl) != 0) + nvme_scan_ns_sequential(ctrl); mutex_unlock(&ctrl->scan_lock); down_write(&ctrl->namespaces_rwsem); -- 2.11.0