LKML Archive on lore.kernel.org
 help / color / Atom feed
From: "Ahmed S. Darwish" <a.darwish@linutronix.de>
To: "James E.J. Bottomley" <jejb@linux.ibm.com>,
	"Martin K. Petersen" <martin.petersen@oracle.com>,
	Christoph Hellwig <hch@infradead.org>,
	John Garry <john.garry@huawei.com>,
	Jason Yan <yanaijie@huawei.com>, Daniel Wagner <dwagner@suse.de>,
	Artur Paszkiewicz <artur.paszkiewicz@intel.com>,
	Jack Wang <jinpu.wang@cloud.ionos.com>
Cc: linux-scsi@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	"Sebastian A. Siewior" <bigeasy@linutronix.de>,
	"Ahmed S. Darwish" <a.darwish@linutronix.de>
Subject: [PATCH v3 03/19] scsi: libsas: Introduce a _gfp() variant of event notifiers
Date: Mon, 18 Jan 2021 11:09:39 +0100
Message-ID: <20210118100955.1761652-4-a.darwish@linutronix.de> (raw)
In-Reply-To: <20210118100955.1761652-1-a.darwish@linutronix.de>

sas_alloc_event() uses in_interrupt() to decide which allocation should
be used.

The usage of in_interrupt() in drivers is phased out and Linus clearly
requested that code which changes behaviour depending on context should
either be separated or the context be conveyed in an argument passed by
the caller, which usually knows the context.

The in_interrupt() check is also only partially correct, because it
fails to choose the correct code path when just preemption or interrupts
are disabled. For example, as in the following call chain:

  mvsas/mv_sas.c: mvs_work_queue() [process context]
  spin_lock_irqsave(mvs_info::lock, )
    -> libsas/sas_event.c: sas_notify_phy_event()
      -> sas_alloc_event()
        -> in_interrupt() = false
          -> invalid GFP_KERNEL allocation
    -> libsas/sas_event.c: sas_notify_port_event()
      -> sas_alloc_event()
        -> in_interrupt() = false
          -> invalid GFP_KERNEL allocation

Introduce sas_alloc_event_gfp(), sas_notify_port_event_gfp(), and
sas_notify_phy_event_gfp(), which all behave like the non _gfp()
variants but use a caller-passed GFP mask for allocations.

For bisectability, all callers will be modified first to pass GFP
context, then the non _gfp() libsas API variants will be modified to
take a gfp_t by default.

Fixes: 1c393b970e0f ("scsi: libsas: Use dynamic alloced work to avoid sas event lost")
Signed-off-by: Ahmed S. Darwish <a.darwish@linutronix.de>
Reviewed-by: John Garry <john.garry@huawei.com>
Cc: Jason Yan <yanaijie@huawei.com>
---
 Documentation/scsi/libsas.rst      |  2 +
 drivers/scsi/libsas/sas_event.c    | 67 ++++++++++++++++++++++++------
 drivers/scsi/libsas/sas_init.c     | 21 +++++++---
 drivers/scsi/libsas/sas_internal.h |  4 ++
 include/scsi/libsas.h              |  4 ++
 5 files changed, 80 insertions(+), 18 deletions(-)

diff --git a/Documentation/scsi/libsas.rst b/Documentation/scsi/libsas.rst
index 6722e352444b..ea63ab3a9216 100644
--- a/Documentation/scsi/libsas.rst
+++ b/Documentation/scsi/libsas.rst
@@ -191,6 +191,8 @@ The event interface::
 	/* LLDD calls these to notify the class of an event. */
 	void sas_notify_port_event(struct sas_phy *, enum port_event);
 	void sas_notify_phy_event(struct sas_phy *, enum phy_event);
+	void sas_notify_port_event_gfp(struct sas_phy *, enum port_event, gfp_t);
+	void sas_notify_phy_event_gfp(struct sas_phy *, enum phy_event, gfp_t);
 
 The port notification::
 
diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c
index 112a1b76f63b..ba266a17250a 100644
--- a/drivers/scsi/libsas/sas_event.c
+++ b/drivers/scsi/libsas/sas_event.c
@@ -131,18 +131,15 @@ static void sas_phy_event_worker(struct work_struct *work)
 	sas_free_event(ev);
 }
 
-int sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event)
+static int __sas_notify_port_event(struct asd_sas_phy *phy,
+				   enum port_event event,
+				   struct asd_sas_event *ev)
 {
-	struct asd_sas_event *ev;
 	struct sas_ha_struct *ha = phy->ha;
 	int ret;
 
 	BUG_ON(event >= PORT_NUM_EVENTS);
 
-	ev = sas_alloc_event(phy);
-	if (!ev)
-		return -ENOMEM;
-
 	INIT_SAS_EVENT(ev, sas_port_event_worker, phy, event);
 
 	ret = sas_queue_event(event, &ev->work, ha);
@@ -151,20 +148,41 @@ int sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event)
 
 	return ret;
 }
+
+int sas_notify_port_event_gfp(struct asd_sas_phy *phy, enum port_event event,
+			      gfp_t gfp_flags)
+{
+	struct asd_sas_event *ev;
+
+	ev = sas_alloc_event_gfp(phy, gfp_flags);
+	if (!ev)
+		return -ENOMEM;
+
+	return __sas_notify_port_event(phy, event, ev);
+}
+EXPORT_SYMBOL_GPL(sas_notify_port_event_gfp);
+
+int sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event)
+{
+	struct asd_sas_event *ev;
+
+	ev = sas_alloc_event(phy);
+	if (!ev)
+		return -ENOMEM;
+
+	return __sas_notify_port_event(phy, event, ev);
+}
 EXPORT_SYMBOL_GPL(sas_notify_port_event);
 
-int sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event)
+static inline int __sas_notify_phy_event(struct asd_sas_phy *phy,
+					 enum phy_event event,
+					 struct asd_sas_event *ev)
 {
-	struct asd_sas_event *ev;
 	struct sas_ha_struct *ha = phy->ha;
 	int ret;
 
 	BUG_ON(event >= PHY_NUM_EVENTS);
 
-	ev = sas_alloc_event(phy);
-	if (!ev)
-		return -ENOMEM;
-
 	INIT_SAS_EVENT(ev, sas_phy_event_worker, phy, event);
 
 	ret = sas_queue_event(event, &ev->work, ha);
@@ -173,5 +191,28 @@ int sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event)
 
 	return ret;
 }
+
+int sas_notify_phy_event_gfp(struct asd_sas_phy *phy, enum phy_event event,
+			     gfp_t gfp_flags)
+{
+	struct asd_sas_event *ev;
+
+	ev = sas_alloc_event_gfp(phy, gfp_flags);
+	if (!ev)
+		return -ENOMEM;
+
+	return __sas_notify_phy_event(phy, event, ev);
+}
+EXPORT_SYMBOL_GPL(sas_notify_phy_event_gfp);
+
+int sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event)
+{
+	struct asd_sas_event *ev;
+
+	ev = sas_alloc_event(phy);
+	if (!ev)
+		return -ENOMEM;
+
+	return __sas_notify_phy_event(phy, event, ev);
+}
 EXPORT_SYMBOL_GPL(sas_notify_phy_event);
-
diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index 6dc2505d36af..f8ae1f0f17d3 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -584,16 +584,15 @@ sas_domain_attach_transport(struct sas_domain_function_template *dft)
 }
 EXPORT_SYMBOL_GPL(sas_domain_attach_transport);
 
-
-struct asd_sas_event *sas_alloc_event(struct asd_sas_phy *phy)
+static struct asd_sas_event *__sas_alloc_event(struct asd_sas_phy *phy,
+					       gfp_t gfp_flags)
 {
 	struct asd_sas_event *event;
-	gfp_t flags = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL;
 	struct sas_ha_struct *sas_ha = phy->ha;
 	struct sas_internal *i =
 		to_sas_internal(sas_ha->core.shost->transportt);
 
-	event = kmem_cache_zalloc(sas_event_cache, flags);
+	event = kmem_cache_zalloc(sas_event_cache, gfp_flags);
 	if (!event)
 		return NULL;
 
@@ -604,7 +603,8 @@ struct asd_sas_event *sas_alloc_event(struct asd_sas_phy *phy)
 			if (cmpxchg(&phy->in_shutdown, 0, 1) == 0) {
 				pr_notice("The phy%d bursting events, shut it down.\n",
 					  phy->id);
-				sas_notify_phy_event(phy, PHYE_SHUTDOWN);
+				sas_notify_phy_event_gfp(phy, PHYE_SHUTDOWN,
+							 gfp_flags);
 			}
 		} else {
 			/* Do not support PHY control, stop allocating events */
@@ -618,6 +618,17 @@ struct asd_sas_event *sas_alloc_event(struct asd_sas_phy *phy)
 	return event;
 }
 
+struct asd_sas_event *sas_alloc_event(struct asd_sas_phy *phy)
+{
+	return __sas_alloc_event(phy, in_interrupt() ? GFP_ATOMIC : GFP_KERNEL);
+}
+
+struct asd_sas_event *sas_alloc_event_gfp(struct asd_sas_phy *phy,
+					  gfp_t gfp_flags)
+{
+	return __sas_alloc_event(phy, gfp_flags);
+}
+
 void sas_free_event(struct asd_sas_event *event)
 {
 	struct asd_sas_phy *phy = event->phy;
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index 53ea32ed17a7..52e09c3e2b50 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -49,6 +49,8 @@ int  sas_register_phys(struct sas_ha_struct *sas_ha);
 void sas_unregister_phys(struct sas_ha_struct *sas_ha);
 
 struct asd_sas_event *sas_alloc_event(struct asd_sas_phy *phy);
+struct asd_sas_event *sas_alloc_event_gfp(struct asd_sas_phy *phy,
+					  gfp_t gfp_flags);
 void sas_free_event(struct asd_sas_event *event);
 
 int  sas_register_ports(struct sas_ha_struct *sas_ha);
@@ -77,6 +79,8 @@ int sas_smp_phy_control(struct domain_device *dev, int phy_id,
 int sas_smp_get_phy_events(struct sas_phy *phy);
 
 int sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event);
+int sas_notify_phy_event_gfp(struct asd_sas_phy *phy, enum phy_event event,
+			     gfp_t flags);
 void sas_device_set_phy(struct domain_device *dev, struct sas_port *port);
 struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy);
 struct domain_device *sas_ex_to_ata(struct domain_device *ex_dev, int phy_id);
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 3387149502e9..e6a43163ab5b 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -704,5 +704,9 @@ int sas_request_addr(struct Scsi_Host *shost, u8 *addr);
 
 int sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event);
 int sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event);
+int sas_notify_port_event_gfp(struct asd_sas_phy *phy, enum port_event event,
+			      gfp_t gfp_flags);
+int sas_notify_phy_event_gfp(struct asd_sas_phy *phy, enum phy_event event,
+			     gfp_t gfp_flags);
 
 #endif /* _SASLIB_H_ */
-- 
2.30.0


  parent reply index

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-18 10:09 [PATCH v3 00/19] scsi: libsas: Remove in_interrupt() check Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 01/19] Documentation: scsi: libsas: Remove notify_ha_event() Ahmed S. Darwish
2021-01-18 10:22   ` Jinpu Wang
2021-01-18 10:09 ` [PATCH v3 02/19] scsi: libsas and users: Remove notifier indirection Ahmed S. Darwish
2021-01-18 10:26   ` Jinpu Wang
2021-01-18 10:09 ` Ahmed S. Darwish [this message]
2021-01-18 10:09 ` [PATCH v3 04/19] scsi: mvsas: Pass gfp_t flags to libsas event notifiers Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 05/19] scsi: isci: port: link down: Pass gfp_t flags Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 06/19] scsi: isci: port: link up: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 07/19] scsi: isci: port: broadcast change: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 08/19] scsi: libsas: Pass gfp_t flags to event notifiers Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 09/19] scsi: pm80xx: Pass gfp_t flags to libsas " Ahmed S. Darwish
2021-01-18 10:26   ` Jinpu Wang
2021-01-18 10:09 ` [PATCH v3 10/19] scsi: aic94xx: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 11/19] scsi: hisi_sas: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 12/19] scsi: libsas: event notifiers API: Add gfp_t flags parameter Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 13/19] scsi: hisi_sas: Switch back to original libsas event notifiers Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 14/19] scsi: aic94xx: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 15/19] scsi: pm80xx: " Ahmed S. Darwish
2021-01-18 10:27   ` Jinpu Wang
2021-01-18 10:09 ` [PATCH v3 16/19] scsi: libsas: Switch back to original event notifiers API Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 17/19] scsi: isci: Switch back to original libsas event notifiers Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 18/19] scsi: mvsas: " Ahmed S. Darwish
2021-01-18 10:09 ` [PATCH v3 19/19] scsi: libsas: Remove temporarily-added _gfp() API variants Ahmed S. Darwish
2021-01-23  2:32 ` [PATCH v3 00/19] scsi: libsas: Remove in_interrupt() check Martin K. Petersen
2021-01-27  4:54 ` Martin K. Petersen

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=20210118100955.1761652-4-a.darwish@linutronix.de \
    --to=a.darwish@linutronix.de \
    --cc=artur.paszkiewicz@intel.com \
    --cc=bigeasy@linutronix.de \
    --cc=dwagner@suse.de \
    --cc=hch@infradead.org \
    --cc=jejb@linux.ibm.com \
    --cc=jinpu.wang@cloud.ionos.com \
    --cc=john.garry@huawei.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-scsi@vger.kernel.org \
    --cc=martin.petersen@oracle.com \
    --cc=tglx@linutronix.de \
    --cc=yanaijie@huawei.com \
    /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

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lkml.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lkml.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lkml.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lkml.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lkml.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lkml.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lkml.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lkml.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lkml.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lkml.kernel.org/lkml/9 lkml/git/9.git
	git clone --mirror https://lkml.kernel.org/lkml/10 lkml/git/10.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lkml.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git