Re: [PATCH] nvme: add 'fail_if_no_path' sysfs attribute
From: Keith Busch <kbusch@kernel.org>
Date: 2021-02-19 23:17:43
On Fri, Feb 19, 2021 at 03:46:25PM +0100, Hannes Reinecke wrote:
In some setups like RAID we need to return an I/O error once all paths are unavailable to allow the upper layers to start their own error recovery (like redirecting I/O to other mirrors). This patch adds a sysfs attribute 'fail_if_no_path' to allow the admin to enable that behaviour instead of the current 'queue until a path becomes available' policy. Signed-off-by: Hannes Reinecke <hare@suse.de>
Sounds okay to me, just some minor nits below.
quoted hunk ↗ jump to hunk
@@ -283,10 +283,13 @@ static bool nvme_available_path(struct nvme_ns_head *head) continue; switch (ns->ctrl->state) { case NVME_CTRL_LIVE: + return true; case NVME_CTRL_RESETTING: case NVME_CTRL_CONNECTING: /* fallthru */ - return true; + if (!test_bit(NVME_NSHEAD_FAIL_IF_NO_PATH, + &head->flags)) + return true;
It doesn't look like the 'fallthru' is in the right place anymore, though I can't tell why it is there in the first place.
quoted hunk ↗ jump to hunk
default: break; }@@ -641,6 +644,37 @@ static ssize_t ana_state_show(struct device *dev, struct device_attribute *attr, } DEVICE_ATTR_RO(ana_state); +static ssize_t fail_if_no_path_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct gendisk *disk = dev_to_disk(dev); + struct nvme_ns_head *head = disk->private_data; + + return sprintf(buf, "%d\n", + test_bit(NVME_NSHEAD_FAIL_IF_NO_PATH, &head->flags) ? + 1 : 0); +} + +static ssize_t fail_if_no_path_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct gendisk *disk = dev_to_disk(dev); + struct nvme_ns_head *head = disk->private_data; + int fail_if_no_path, err; + + err = kstrtoint(buf, 10, &fail_if_no_path); + if (err) + return -EINVAL; + + else if (fail_if_no_path <= 0) + clear_bit(NVME_NSHEAD_FAIL_IF_NO_PATH, &head->flags); + else + set_bit(NVME_NSHEAD_FAIL_IF_NO_PATH, &head->flags);
The extra line above the 'else if' should be removed, or just change it to simply 'if'. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme