From 4e646fa490ba4b782afa188dd8818b94c419924e Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 26 May 2021 16:33:10 -0700 Subject: [PATCH 026/217] ndctl/scrub: Reread scrub-engine status at start Given that the kernel has exponential backoff to cover the lack of interrupts for scrub completion status there is a reasonable likelihood that 'ndctl start-scrub' is issued while the hardware/platform scrub-state is idle, but the kernel engine poll timer has not fired. Trigger at least one poll cycle for the kernel to re-read the scrub-state before reporting that ARS is busy. Link: https://lore.kernel.org/r/162207199057.3715490.2469820075085914776.stgit@dwillia2-desk3.amr.corp.intel.com Reported-by: Krzysztof Rusocki Signed-off-by: Dan Williams Signed-off-by: Vishal Verma --- ndctl/lib/libndctl.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/ndctl/lib/libndctl.c b/ndctl/lib/libndctl.c index e5641fe..536e142 100644 --- a/ndctl/lib/libndctl.c +++ b/ndctl/lib/libndctl.c @@ -1354,8 +1354,18 @@ static int __ndctl_bus_get_scrub_state(struct ndctl_bus *bus, NDCTL_EXPORT int ndctl_bus_start_scrub(struct ndctl_bus *bus) { struct ndctl_ctx *ctx = ndctl_bus_get_ctx(bus); + int rc; + + rc = sysfs_write_attr(ctx, bus->scrub_path, "1\n"); - return sysfs_write_attr(ctx, bus->scrub_path, "1\n"); + /* + * Try at least 1 poll cycle before reporting busy in case this + * request hits the kernel's exponential backoff while the + * hardware/platform scrub state is idle. + */ + if (rc == -EBUSY && ndctl_bus_poll_scrub_completion(bus, 1, 1) == 0) + return sysfs_write_attr(ctx, bus->scrub_path, "1\n"); + return rc; } NDCTL_EXPORT int ndctl_bus_get_scrub_state(struct ndctl_bus *bus) -- 2.27.0