All of lore.kernel.org
 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] acpi, nfit: Further restrict userspace ARS start requests
Date: Mon, 15 Oct 2018 13:46:01 -0700	[thread overview]
Message-ID: <153963636159.2102929.5769352106580143614.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>
---
 drivers/acpi/nfit/core.c |   21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index f7efcd9843e0..0eaf934ca624 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 +3375,22 @@ 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 (test_bit(ARS_REQ_SHORT, &nfit_spa->ars_state)) {
+			rc = -EBUSY;
+			break;
+		} else if (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
Linux-nvdimm@lists.01.org
https://lists.01.org/mailman/listinfo/linux-nvdimm

WARNING: multiple messages have this Message-ID (diff)
From: Dan Williams <dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
To: linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org
Cc: linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: [PATCH] acpi, nfit: Further restrict userspace ARS start requests
Date: Mon, 15 Oct 2018 13:46:01 -0700	[thread overview]
Message-ID: <153963636159.2102929.5769352106580143614.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-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/acpi/nfit/core.c |   21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index f7efcd9843e0..0eaf934ca624 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 +3375,22 @@ 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 (test_bit(ARS_REQ_SHORT, &nfit_spa->ars_state)) {
+			rc = -EBUSY;
+			break;
+		} else if (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 */

             reply	other threads:[~2018-10-15 20:57 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-15 20:46 Dan Williams [this message]
2018-10-15 20:46 ` [PATCH] acpi, nfit: Further restrict userspace ARS start requests Dan Williams

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:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

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

  git send-email \
    --in-reply-to=153963636159.2102929.5769352106580143614.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 \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.