LinuxLists.cc - [PATCH AUTOSEL 6.1 01/53] scsi: iscsi: Fix multiple iSCSI session unbind events sent to userspace

2023-01-16 14:43:11

Subject: [PATCH AUTOSEL 6.1 01/53] scsi: iscsi: Fix multiple iSCSI session unbind events sent to userspace

From: Wenchao Hao <[email protected]>

[ Upstream commit a3be19b91ea7121d388084e8c07f5b1b982eb40c ]

It was observed that the kernel would potentially send
ISCSI_KEVENT_UNBIND_SESSION multiple times. Introduce 'target_state' in
iscsi_cls_session() to make sure session will send only one unbind session
event.

This introduces a regression wrt. the issue fixed in commit 13e60d3ba287
("scsi: iscsi: Report unbind session event when the target has been
removed"). If iscsid dies for any reason after sending an unbind session to
kernel, once iscsid is restarted, the kernel's ISCSI_KEVENT_UNBIND_SESSION
event is lost and userspace is then unable to logout. However, the session
is actually in invalid state (its target_id is INVALID) so iscsid should
not sync this session during restart.

Consequently we need to check the session's target state during iscsid
restart. If session is in unbound state, do not sync this session and
perform session teardown. This is OK because once a session is unbound, we
can not recover it any more (mainly because its target id is INVALID).

Signed-off-by: Wenchao Hao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Mike Christie <[email protected]>
Reviewed-by: Wu Bo <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
drivers/scsi/scsi_transport_iscsi.c | 50 ++++++++++++++++++++++++++---
include/scsi/scsi_transport_iscsi.h | 9 ++++++
2 files changed, 54 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index f473c002fa4d..bf834e72595a 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -1677,6 +1677,13 @@ static const char *iscsi_session_state_name(int state)
return name;
}

+static char *iscsi_session_target_state_name[] = {
+ [ISCSI_SESSION_TARGET_UNBOUND] = "UNBOUND",
+ [ISCSI_SESSION_TARGET_ALLOCATED] = "ALLOCATED",
+ [ISCSI_SESSION_TARGET_SCANNED] = "SCANNED",
+ [ISCSI_SESSION_TARGET_UNBINDING] = "UNBINDING",
+};
+
int iscsi_session_chkready(struct iscsi_cls_session *session)
{
int err;
@@ -1786,9 +1793,13 @@ static int iscsi_user_scan_session(struct device *dev, void *data)
if ((scan_data->channel == SCAN_WILD_CARD ||
scan_data->channel == 0) &&
(scan_data->id == SCAN_WILD_CARD ||
- scan_data->id == id))
+ scan_data->id == id)) {
scsi_scan_target(&session->dev, 0, id,
scan_data->lun, scan_data->rescan);
+ spin_lock_irqsave(&session->lock, flags);
+ session->target_state = ISCSI_SESSION_TARGET_SCANNED;
+ spin_unlock_irqrestore(&session->lock, flags);
+ }
}

user_scan_exit:
@@ -1961,31 +1972,41 @@ static void __iscsi_unbind_session(struct work_struct *work)
struct iscsi_cls_host *ihost = shost->shost_data;
unsigned long flags;
unsigned int target_id;
+ bool remove_target = true;

ISCSI_DBG_TRANS_SESSION(session, "Unbinding session\n");

/* Prevent new scans and make sure scanning is not in progress */
mutex_lock(&ihost->mutex);
spin_lock_irqsave(&session->lock, flags);
- if (session->target_id == ISCSI_MAX_TARGET) {
+ if (session->target_state == ISCSI_SESSION_TARGET_ALLOCATED) {
+ remove_target = false;
+ } else if (session->target_state != ISCSI_SESSION_TARGET_SCANNED) {
spin_unlock_irqrestore(&session->lock, flags);
mutex_unlock(&ihost->mutex);
- goto unbind_session_exit;
+ ISCSI_DBG_TRANS_SESSION(session,
+ "Skipping target unbinding: Session is unbound/unbinding.\n");
+ return;
}

+ session->target_state = ISCSI_SESSION_TARGET_UNBINDING;
target_id = session->target_id;
session->target_id = ISCSI_MAX_TARGET;
spin_unlock_irqrestore(&session->lock, flags);
mutex_unlock(&ihost->mutex);

- scsi_remove_target(&session->dev);
+ if (remove_target)
+ scsi_remove_target(&session->dev);

if (session->ida_used)
ida_free(&iscsi_sess_ida, target_id);

-unbind_session_exit:
iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION);
ISCSI_DBG_TRANS_SESSION(session, "Completed target removal\n");
+
+ spin_lock_irqsave(&session->lock, flags);
+ session->target_state = ISCSI_SESSION_TARGET_UNBOUND;
+ spin_unlock_irqrestore(&session->lock, flags);
}

static void __iscsi_destroy_session(struct work_struct *work)
@@ -2062,6 +2083,9 @@ int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
session->ida_used = true;
} else
session->target_id = target_id;
+ spin_lock_irqsave(&session->lock, flags);
+ session->target_state = ISCSI_SESSION_TARGET_ALLOCATED;
+ spin_unlock_irqrestore(&session->lock, flags);

dev_set_name(&session->dev, "session%u", session->sid);
err = device_add(&session->dev);
@@ -4369,6 +4393,19 @@ iscsi_session_attr(def_taskmgmt_tmo, ISCSI_PARAM_DEF_TASKMGMT_TMO, 0);
iscsi_session_attr(discovery_parent_idx, ISCSI_PARAM_DISCOVERY_PARENT_IDX, 0);
iscsi_session_attr(discovery_parent_type, ISCSI_PARAM_DISCOVERY_PARENT_TYPE, 0);

+static ssize_t
+show_priv_session_target_state(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct iscsi_cls_session *session = iscsi_dev_to_session(dev->parent);
+
+ return sysfs_emit(buf, "%s\n",
+ iscsi_session_target_state_name[session->target_state]);
+}
+
+static ISCSI_CLASS_ATTR(priv_sess, target_state, S_IRUGO,
+ show_priv_session_target_state, NULL);
+
static ssize_t
show_priv_session_state(struct device *dev, struct device_attribute *attr,
char *buf)
@@ -4471,6 +4508,7 @@ static struct attribute *iscsi_session_attrs[] = {
&dev_attr_sess_boot_target.attr,
&dev_attr_priv_sess_recovery_tmo.attr,
&dev_attr_priv_sess_state.attr,
+ &dev_attr_priv_sess_target_state.attr,
&dev_attr_priv_sess_creator.attr,
&dev_attr_sess_chap_out_idx.attr,
&dev_attr_sess_chap_in_idx.attr,
@@ -4584,6 +4622,8 @@ static umode_t iscsi_session_attr_is_visible(struct kobject *kobj,
return S_IRUGO | S_IWUSR;
else if (attr == &dev_attr_priv_sess_state.attr)
return S_IRUGO;
+ else if (attr == &dev_attr_priv_sess_target_state.attr)
+ return S_IRUGO;
else if (attr == &dev_attr_priv_sess_creator.attr)
return S_IRUGO;
else if (attr == &dev_attr_priv_sess_target_id.attr)
diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
index cab52b0f11d0..34c03707fb6e 100644
--- a/include/scsi/scsi_transport_iscsi.h
+++ b/include/scsi/scsi_transport_iscsi.h
@@ -236,6 +236,14 @@ enum {
ISCSI_SESSION_FREE,
};

+enum {
+ ISCSI_SESSION_TARGET_UNBOUND,
+ ISCSI_SESSION_TARGET_ALLOCATED,
+ ISCSI_SESSION_TARGET_SCANNED,
+ ISCSI_SESSION_TARGET_UNBINDING,
+ ISCSI_SESSION_TARGET_MAX,
+};
+
#define ISCSI_MAX_TARGET -1

struct iscsi_cls_session {
@@ -264,6 +272,7 @@ struct iscsi_cls_session {
*/
pid_t creator;
int state;
+ int target_state; /* session target bind state */
int sid; /* session id */
void *dd_data; /* LLD private data */
struct device dev; /* sysfs transport/container device */
--
2.35.1

2023-01-16 14:43:49

Subject: [PATCH AUTOSEL 6.1 01/53] scsi: iscsi: Fix multiple iSCSI session unbind events sent to userspace

Subject: [PATCH AUTOSEL 6.1 45/53] platform/x86: asus-nb-wmi: Add alternate mapping for KEY_CAMERA

Subject: [PATCH AUTOSEL 6.1 49/53] platform/x86: simatic-ipc: correct name of a model

Subject: [PATCH AUTOSEL 6.1 29/53] tools/nolibc: fix missing includes causing build issues at -O0

Subject: [PATCH AUTOSEL 6.1 48/53] platform/x86: asus-wmi: Ignore fan on E410MA

Subject: [PATCH AUTOSEL 6.1 11/53] ASoC: amd: yc: Add ASUS M5402RA into DMI table

Subject: [PATCH AUTOSEL 6.1 27/53] nolibc: fix fd_set type

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Subject: [PATCH AUTOSEL 6.1 44/53] platform/x86: touchscreen_dmi: Add info for the CSL Panther Tab HD

Subject: [PATCH AUTOSEL 6.1 53/53] firmware: coreboot: Check size of table entry and use flex-array

Subject: [PATCH AUTOSEL 6.1 35/53] drm/amdkfd: Add sync after creating vram bo

Subject: [PATCH AUTOSEL 6.1 04/53] ASoC: SOF: Add FW state to debugfs

Subject: [PATCH AUTOSEL 6.1 13/53] kcsan: test: don't put the expect array on the stack

Subject: [PATCH AUTOSEL 6.1 17/53] net: usb: cdc_ether: add support for Thales Cinterion PLS62-W modem

Subject: [PATCH AUTOSEL 6.1 26/53] arm64/mm: Define dummy pud_user_exec() when using 2-level page-table

Subject: [PATCH AUTOSEL 6.1 25/53] perf/x86/intel/uncore: Add Emerald Rapids

Subject: [PATCH AUTOSEL 6.1 21/53] xen/pvcalls: free active map buffer on pvcalls_front_free_map

Subject: [PATCH AUTOSEL 6.1 41/53] scsi: hisi_sas: Use abort task set to reset SAS disks when discovered

Subject: [PATCH AUTOSEL 6.1 18/53] drm: Add orientation quirk for Lenovo ideapad D330-10IGL

Subject: [PATCH AUTOSEL 6.1 40/53] KVM: s390: interrupt: use READ_ONCE() before cmpxchg()

Subject: [PATCH AUTOSEL 6.1 43/53] r8152: add vendor/device ID pair for Microsoft Devkit

Subject: [PATCH AUTOSEL 6.1 38/53] spi: spidev: fix a race condition when accessing spidev->spi

Subject: [PATCH AUTOSEL 6.1 52/53] ata: pata_cs5535: Don't build on UML

Subject: [PATCH AUTOSEL 6.1 47/53] platform/x86: asus-wmi: Add quirk wmi_ignore_fan

Subject: [PATCH AUTOSEL 6.1 05/53] ASoC: amd: yc: Add Razer Blade 14 2022 into DMI table

Subject: [PATCH AUTOSEL 6.1 14/53] cpufreq: Add SM6375 to cpufreq-dt-platdev blocklist

Subject: [PATCH AUTOSEL 6.1 06/53] spi: cadence: Fix busy cycles calculation

Subject: [PATCH AUTOSEL 6.1 09/53] ASoC: mediatek: mt8186: support rt5682s_max98360

Subject: [PATCH AUTOSEL 6.1 32/53] ASoC: fsl_ssi: Rename AC'97 streams to avoid collisions with AC'97 CODEC

Subject: [PATCH AUTOSEL 6.1 16/53] drm/msm/a6xx: Avoid gx gbit halt during rpm suspend

Subject: [PATCH AUTOSEL 6.1 42/53] scsi: hisi_sas: Set a port invalid only if there are no devices attached when refreshing port id

Subject: [PATCH AUTOSEL 6.1 37/53] cifs: fix potential memory leaks in session setup