nvdimm.lists.linux.dev archive mirror
 help / color / mirror / Atom feed
From: Dan Williams <dan.j.williams@intel.com>
To: linux-nvdimm@lists.01.org
Cc: linux-acpi@vger.kernel.org
Subject: [PATCH v2] acpi, nfit: Further restrict userspace ARS start requests
Date: Mon, 15 Oct 2018 14:00:48 -0700	[thread overview]
Message-ID: <153963719771.2140296.1457598322723171137.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)

In addition to not allowing ARS start while the background thread is
actively running, prevent ARS start while any scrub request is pending.

This aligns the window for ARS start submission with the status of ARS
reported via sysfs. Previously userspace could sneak its own ARS start
requests in while sysfs reported -EBUSY.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Changes in v2:
* Require acpi_desc->scrub_spa to be NULL to prevent requests being sent
  while a scrub is active, or whose results are waiting to be reaped.

 drivers/acpi/nfit/core.c |   19 ++++++++++++++-----
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index f7efcd9843e0..253c0e85554d 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -3364,6 +3364,8 @@ static int __acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc,
 		struct nvdimm *nvdimm, unsigned int cmd)
 	struct acpi_nfit_desc *acpi_desc = to_acpi_nfit_desc(nd_desc);
+	struct nfit_spa *nfit_spa;
+	int rc = 0;
 	if (nvdimm)
 		return 0;
@@ -3373,13 +3375,20 @@ static int __acpi_nfit_clear_to_send(struct nvdimm_bus_descriptor *nd_desc,
 	 * The kernel and userspace may race to initiate a scrub, but
 	 * the scrub thread is prepared to lose that initial race.  It
-	 * just needs guarantees that any ars it initiates are not
-	 * interrupted by any intervening start reqeusts from userspace.
+	 * just needs guarantees that any ARS it initiates are not
+	 * interrupted by any intervening start requests from userspace.
-	if (work_busy(&acpi_desc->dwork.work))
-		return -EBUSY;
+	mutex_lock(&acpi_desc->init_mutex);
+	list_for_each_entry(nfit_spa, &acpi_desc->spas, list)
+		if (acpi_desc->scrub_spa
+				|| test_bit(ARS_REQ_SHORT, &nfit_spa->ars_state)
+				|| test_bit(ARS_REQ_LONG, &nfit_spa->ars_state)) {
+			rc = -EBUSY;
+			break;
+		}
+	mutex_unlock(&acpi_desc->init_mutex);
-	return 0;
+	return rc;
 /* prevent security commands from being issued via ioctl */

Linux-nvdimm mailing list

             reply	other threads:[~2018-10-15 21:12 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-15 21:00 Dan Williams [this message]
2018-10-15 21:24 ` Dave Jiang

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=153963719771.2140296.1457598322723171137.stgit@dwillia2-desk3.amr.corp.intel.com \
    --to=dan.j.williams@intel.com \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-nvdimm@lists.01.org \
    --subject='Re: [PATCH v2] acpi, nfit: Further restrict userspace ARS start requests' \


* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).