[PATCH resend 0/3] couple of nvme patches resend

[PATCH resend 0/3] couple of nvme patches resend

[Sagi Grimberg]

Seems these got positive feedback (informally) but were left behind..

Roy Shterman (1):
  nvme-core/loop/rdma: Host delete_work and reset_work on separate
    workqueues

Sagi Grimberg (2):
  nvme-pci: serialize pci resets
  nvme-pci: allocate device queues storage space at probe

 drivers/nvme/host/core.c   | 47 ++++++++++++++++++++++++++++-----
 drivers/nvme/host/nvme.h   |  3 +++
 drivers/nvme/host/pci.c    | 65 +++++++++++++++++++---------------------------
 drivers/nvme/host/rdma.c   |  2 +-
 drivers/nvme/target/loop.c |  2 +-
 5 files changed, 73 insertions(+), 46 deletions(-)

-- 
2.14.1

[PATCH resend 1/3] nvme-pci: serialize pci resets

[Sagi Grimberg]

Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
---
 drivers/nvme/host/core.c | 3 ++-
 drivers/nvme/host/nvme.h | 1 +
 drivers/nvme/host/pci.c  | 2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 921e0fe46775..d30f21aa0828 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -95,7 +95,7 @@ int nvme_reset_ctrl(struct nvme_ctrl *ctrl)
 }
 EXPORT_SYMBOL_GPL(nvme_reset_ctrl);
 
-static int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl)
+int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl)
 {
 	int ret;
 
@@ -104,6 +104,7 @@ static int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl)
 		flush_work(&ctrl->reset_work);
 	return ret;
 }
+EXPORT_SYMBOL_GPL(nvme_reset_ctrl_sync);
 
 static void nvme_delete_ctrl_work(struct work_struct *work)
 {
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 5aadfe504e5d..6097091bab42 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -394,6 +394,7 @@ int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count);
 void nvme_start_keep_alive(struct nvme_ctrl *ctrl);
 void nvme_stop_keep_alive(struct nvme_ctrl *ctrl);
 int nvme_reset_ctrl(struct nvme_ctrl *ctrl);
+int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl);
 int nvme_delete_ctrl(struct nvme_ctrl *ctrl);
 int nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl);
 
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 45f843d0cdf9..6ba59566d9fb 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2535,7 +2535,7 @@ static void nvme_reset_prepare(struct pci_dev *pdev)
 static void nvme_reset_done(struct pci_dev *pdev)
 {
 	struct nvme_dev *dev = pci_get_drvdata(pdev);
-	nvme_reset_ctrl(&dev->ctrl);
+	nvme_reset_ctrl_sync(&dev->ctrl);
 }
 
 static void nvme_shutdown(struct pci_dev *pdev)
-- 
2.14.1

[PATCH resend 2/3] nvme-pci: allocate device queues storage space at probe

[Sagi Grimberg]

It may cause race by setting 'nvmeq' in nvme_init_request()
because .init_request is called inside switching io scheduler, which
may happen when the NVMe device is being resetted and its nvme queues
are being freed and created. We don't have any sync between the two
pathes.

This patch changes the nvmeq allocation to occur at probe time so
there is no way we can dereference it at init_request.

[   93.268391] kernel BUG at drivers/nvme/host/pci.c:408!
[   93.274146] invalid opcode: 0000 [#1] SMP
[   93.278618] Modules linked in: nfsv3 nfs_acl rpcsec_gss_krb5 auth_rpcgss
nfsv4 dns_resolver nfs lockd grace fscache sunrpc ipmi_ssif vfat fat
intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel
kvm irqbypass crct10dif_pclmul crc32_pclmul ghash_clmulni_intel iTCO_wdt
intel_cstate ipmi_si iTCO_vendor_support intel_uncore mxm_wmi mei_me
ipmi_devintf intel_rapl_perf pcspkr sg ipmi_msghandler lpc_ich dcdbas mei
shpchp acpi_power_meter wmi dm_multipath ip_tables xfs libcrc32c sd_mod
mgag200 i2c_algo_bit drm_kms_helper syscopyarea sysfillrect sysimgblt
fb_sys_fops ttm drm ahci libahci nvme libata crc32c_intel nvme_core tg3
megaraid_sas ptp i2c_core pps_core dm_mirror dm_region_hash dm_log dm_mod
[   93.349071] CPU: 5 PID: 1842 Comm: sh Not tainted 4.15.0-rc2.ming+ #4
[   93.356256] Hardware name: Dell Inc. PowerEdge R730xd/072T6D, BIOS 2.5.5 08/16/2017
[   93.364801] task: 00000000fb8abf2a task.stack: 0000000028bd82d1
[   93.371408] RIP: 0010:nvme_init_request+0x36/0x40 [nvme]
[   93.377333] RSP: 0018:ffffc90002537ca8 EFLAGS: 00010246
[   93.383161] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000008
[   93.391122] RDX: 0000000000000000 RSI: ffff880276ae0000 RDI: ffff88047bae9008
[   93.399084] RBP: ffff88047bae9008 R08: ffff88047bae9008 R09: 0000000009dabc00
[   93.407045] R10: 0000000000000004 R11: 000000000000299c R12: ffff880186bc1f00
[   93.415007] R13: ffff880276ae0000 R14: 0000000000000000 R15: 0000000000000071
[   93.422969] FS:  00007f33cf288740(0000) GS:ffff88047ba80000(0000) knlGS:0000000000000000
[   93.431996] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   93.438407] CR2: 00007f33cf28e000 CR3: 000000047e5bb006 CR4: 00000000001606e0
[   93.446368] Call Trace:
[   93.449103]  blk_mq_alloc_rqs+0x231/0x2a0
[   93.453579]  blk_mq_sched_alloc_tags.isra.8+0x42/0x80
[   93.459214]  blk_mq_init_sched+0x7e/0x140
[   93.463687]  elevator_switch+0x5a/0x1f0
[   93.467966]  ? elevator_get.isra.17+0x52/0xc0
[   93.472826]  elv_iosched_store+0xde/0x150
[   93.477299]  queue_attr_store+0x4e/0x90
[   93.481580]  kernfs_fop_write+0xfa/0x180
[   93.485958]  __vfs_write+0x33/0x170
[   93.489851]  ? __inode_security_revalidate+0x4c/0x60
[   93.495390]  ? selinux_file_permission+0xda/0x130
[   93.500641]  ? _cond_resched+0x15/0x30
[   93.504815]  vfs_write+0xad/0x1a0
[   93.508512]  SyS_write+0x52/0xc0
[   93.512113]  do_syscall_64+0x61/0x1a0
[   93.516199]  entry_SYSCALL64_slow_path+0x25/0x25
[   93.521351] RIP: 0033:0x7f33ce96aab0
[   93.525337] RSP: 002b:00007ffe57570238 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[   93.533785] RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f33ce96aab0
[   93.541746] RDX: 0000000000000006 RSI: 00007f33cf28e000 RDI: 0000000000000001
[   93.549707] RBP: 00007f33cf28e000 R08: 000000000000000a R09: 00007f33cf288740
[   93.557669] R10: 00007f33cf288740 R11: 0000000000000246 R12: 00007f33cec42400
[   93.565630] R13: 0000000000000006 R14: 0000000000000001 R15: 0000000000000000
[   93.573592] Code: 4c 8d 40 08 4c 39 c7 74 16 48 8b 00 48 8b 04 08 48 85 c0
74 16 48 89 86 78 01 00 00 31 c0 c3 8d 4a 01 48 63 c9 48 c1 e1 03 eb de <0f>
0b 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 85 f6 53 48 89
[   93.594676] RIP: nvme_init_request+0x36/0x40 [nvme] RSP: ffffc90002537ca8
[   93.602273] ---[ end trace 810dde3993e5f14e ]---

Reported-by: Yi Zhang <yi.zhang at redhat.com>
Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
---
 drivers/nvme/host/pci.c | 63 ++++++++++++++++++++-----------------------------
 1 file changed, 26 insertions(+), 37 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 6ba59566d9fb..293357b74860 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -75,7 +75,7 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown);
  * Represents an NVM Express device.  Each nvme_dev is a PCI function.
  */
 struct nvme_dev {
-	struct nvme_queue **queues;
+	struct nvme_queue *queues;
 	struct blk_mq_tag_set tagset;
 	struct blk_mq_tag_set admin_tagset;
 	u32 __iomem *dbs;
@@ -365,7 +365,7 @@ static int nvme_admin_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 				unsigned int hctx_idx)
 {
 	struct nvme_dev *dev = data;
-	struct nvme_queue *nvmeq = dev->queues[0];
+	struct nvme_queue *nvmeq = &dev->queues[0];
 
 	WARN_ON(hctx_idx != 0);
 	WARN_ON(dev->admin_tagset.tags[0] != hctx->tags);
@@ -387,7 +387,7 @@ static int nvme_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
 			  unsigned int hctx_idx)
 {
 	struct nvme_dev *dev = data;
-	struct nvme_queue *nvmeq = dev->queues[hctx_idx + 1];
+	struct nvme_queue *nvmeq = &dev->queues[hctx_idx + 1];
 
 	if (!nvmeq->tags)
 		nvmeq->tags = &dev->tagset.tags[hctx_idx];
@@ -403,7 +403,7 @@ static int nvme_init_request(struct blk_mq_tag_set *set, struct request *req,
 	struct nvme_dev *dev = set->driver_data;
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	int queue_idx = (set == &dev->tagset) ? hctx_idx + 1 : 0;
-	struct nvme_queue *nvmeq = dev->queues[queue_idx];
+	struct nvme_queue *nvmeq = &dev->queues[queue_idx];
 
 	BUG_ON(!nvmeq);
 	iod->nvmeq = nvmeq;
@@ -1044,7 +1044,7 @@ static int nvme_poll(struct blk_mq_hw_ctx *hctx, unsigned int tag)
 static void nvme_pci_submit_async_event(struct nvme_ctrl *ctrl)
 {
 	struct nvme_dev *dev = to_nvme_dev(ctrl);
-	struct nvme_queue *nvmeq = dev->queues[0];
+	struct nvme_queue *nvmeq = &dev->queues[0];
 	struct nvme_command c;
 
 	memset(&c, 0, sizeof(c));
@@ -1280,7 +1280,6 @@ static void nvme_free_queue(struct nvme_queue *nvmeq)
 	if (nvmeq->sq_cmds)
 		dma_free_coherent(nvmeq->q_dmadev, SQ_SIZE(nvmeq->q_depth),
 					nvmeq->sq_cmds, nvmeq->sq_dma_addr);
-	kfree(nvmeq);
 }
 
 static void nvme_free_queues(struct nvme_dev *dev, int lowest)
@@ -1288,10 +1287,8 @@ static void nvme_free_queues(struct nvme_dev *dev, int lowest)
 	int i;
 
 	for (i = dev->ctrl.queue_count - 1; i >= lowest; i--) {
-		struct nvme_queue *nvmeq = dev->queues[i];
 		dev->ctrl.queue_count--;
-		dev->queues[i] = NULL;
-		nvme_free_queue(nvmeq);
+		nvme_free_queue(&dev->queues[i]);
 	}
 }
 
@@ -1323,10 +1320,8 @@ static int nvme_suspend_queue(struct nvme_queue *nvmeq)
 
 static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
 {
-	struct nvme_queue *nvmeq = dev->queues[0];
+	struct nvme_queue *nvmeq = &dev->queues[0];
 
-	if (!nvmeq)
-		return;
 	if (nvme_suspend_queue(nvmeq))
 		return;
 
@@ -1382,13 +1377,10 @@ static int nvme_alloc_sq_cmds(struct nvme_dev *dev, struct nvme_queue *nvmeq,
 	return 0;
 }
 
-static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
-							int depth, int node)
+static int nvme_alloc_queue(struct nvme_dev *dev, int qid,
+		int depth, int node)
 {
-	struct nvme_queue *nvmeq = kzalloc_node(sizeof(*nvmeq), GFP_KERNEL,
-							node);
-	if (!nvmeq)
-		return NULL;
+	struct nvme_queue *nvmeq = &dev->queues[qid];
 
 	nvmeq->cqes = dma_zalloc_coherent(dev->dev, CQ_SIZE(depth),
 					  &nvmeq->cq_dma_addr, GFP_KERNEL);
@@ -1407,17 +1399,15 @@ static struct nvme_queue *nvme_alloc_queue(struct nvme_dev *dev, int qid,
 	nvmeq->q_depth = depth;
 	nvmeq->qid = qid;
 	nvmeq->cq_vector = -1;
-	dev->queues[qid] = nvmeq;
 	dev->ctrl.queue_count++;
 
-	return nvmeq;
+	return 0;
 
  free_cqdma:
 	dma_free_coherent(dev->dev, CQ_SIZE(depth), (void *)nvmeq->cqes,
 							nvmeq->cq_dma_addr);
  free_nvmeq:
-	kfree(nvmeq);
-	return NULL;
+	return -ENOMEM;
 }
 
 static int queue_request_irq(struct nvme_queue *nvmeq)
@@ -1590,14 +1580,12 @@ static int nvme_pci_configure_admin_queue(struct nvme_dev *dev)
 	if (result < 0)
 		return result;
 
-	nvmeq = dev->queues[0];
-	if (!nvmeq) {
-		nvmeq = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH,
-					dev_to_node(dev->dev));
-		if (!nvmeq)
-			return -ENOMEM;
-	}
+	result = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH,
+			dev_to_node(dev->dev));
+	if (result)
+		return result;
 
+	nvmeq = &dev->queues[0];
 	aqa = nvmeq->q_depth - 1;
 	aqa |= aqa << 16;
 
@@ -1627,7 +1615,7 @@ static int nvme_create_io_queues(struct nvme_dev *dev)
 
 	for (i = dev->ctrl.queue_count; i <= dev->max_qid; i++) {
 		/* vector == qid - 1, match nvme_create_queue */
-		if (!nvme_alloc_queue(dev, i, dev->q_depth,
+		if (nvme_alloc_queue(dev, i, dev->q_depth,
 		     pci_irq_get_node(to_pci_dev(dev->dev), i - 1))) {
 			ret = -ENOMEM;
 			break;
@@ -1636,7 +1624,7 @@ static int nvme_create_io_queues(struct nvme_dev *dev)
 
 	max = min(dev->max_qid, dev->ctrl.queue_count - 1);
 	for (i = dev->online_queues; i <= max; i++) {
-		ret = nvme_create_queue(dev->queues[i], i);
+		ret = nvme_create_queue(&dev->queues[i], i);
 		if (ret)
 			break;
 	}
@@ -1892,7 +1880,7 @@ static int nvme_setup_host_mem(struct nvme_dev *dev)
 
 static int nvme_setup_io_queues(struct nvme_dev *dev)
 {
-	struct nvme_queue *adminq = dev->queues[0];
+	struct nvme_queue *adminq = &dev->queues[0];
 	struct pci_dev *pdev = to_pci_dev(dev->dev);
 	int result, nr_io_queues;
 	unsigned long size;
@@ -2018,7 +2006,7 @@ static void nvme_disable_io_queues(struct nvme_dev *dev, int queues)
  retry:
 		timeout = ADMIN_TIMEOUT;
 		for (; i > 0; i--, sent++)
-			if (nvme_delete_queue(dev->queues[i], opcode))
+			if (nvme_delete_queue(&dev->queues[i], opcode))
 				break;
 
 		while (sent--) {
@@ -2210,7 +2198,7 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 
 	queues = dev->online_queues - 1;
 	for (i = dev->ctrl.queue_count - 1; i > 0; i--)
-		nvme_suspend_queue(dev->queues[i]);
+		nvme_suspend_queue(&dev->queues[i]);
 
 	if (dead) {
 		/* A device might become IO incapable very soon during
@@ -2218,7 +2206,7 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 		 * queue_count can be 0 here.
 		 */
 		if (dev->ctrl.queue_count)
-			nvme_suspend_queue(dev->queues[0]);
+			nvme_suspend_queue(&dev->queues[0]);
 	} else {
 		nvme_disable_io_queues(dev, queues);
 		nvme_disable_admin_queue(dev, shutdown);
@@ -2480,8 +2468,9 @@ static int nvme_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	dev = kzalloc_node(sizeof(*dev), GFP_KERNEL, node);
 	if (!dev)
 		return -ENOMEM;
-	dev->queues = kzalloc_node((num_possible_cpus() + 1) * sizeof(void *),
-							GFP_KERNEL, node);
+
+	dev->queues = kcalloc_node(num_possible_cpus() + 1,
+			sizeof(struct nvme_queue), GFP_KERNEL, node);
 	if (!dev->queues)
 		goto free;
 
-- 
2.14.1

[PATCH resend 3/3] nvme-core/loop/rdma: Host delete_work and reset_work on separate workqueues

[Sagi Grimberg]

From: Roy Shterman <roys@lightbitslabs.com>

We need to ensure that delete_work will be hosted on a different
workqueue than all the works we flush or cancel from it.
Otherwise we may hit a circular dependency warning [1].

Also, given that delete_work flushes reset_work, host reset_work
on nvme_reset_wq and delete_work on nvme_delete_wq. In addition,
fix the flushing in the individual drivers to flush nvme_delete_wq
when draining queued deletes.

[1]:
[  178.491942] =============================================
[  178.492718] [ INFO: possible recursive locking detected ]
[  178.493495] 4.9.0-rc4-c844263313a8-lb #3 Tainted: G           OE
[  178.494382] ---------------------------------------------
[  178.495160] kworker/5:1/135 is trying to acquire lock:
[  178.495894]  (
[  178.496120] "nvme-wq"
[  178.496471] ){++++.+}
[  178.496599] , at:
[  178.496921] [<ffffffffa70ac206>] flush_work+0x1a6/0x2d0
[  178.497670]
               but task is already holding lock:
[  178.498499]  (
[  178.498724] "nvme-wq"
[  178.499074] ){++++.+}
[  178.499202] , at:
[  178.499520] [<ffffffffa70ad6c2>] process_one_work+0x162/0x6a0
[  178.500343]
               other info that might help us debug this:
[  178.501269]  Possible unsafe locking scenario:

[  178.502113]        CPU0
[  178.502472]        ----
[  178.502829]   lock(
[  178.503115] "nvme-wq"
[  178.503467] );
[  178.503716]   lock(
[  178.504001] "nvme-wq"
[  178.504353] );
[  178.504601]
                *** DEADLOCK ***

[  178.505441]  May be due to missing lock nesting notation

[  178.506453] 2 locks held by kworker/5:1/135:
[  178.507068]  #0:
[  178.507330]  (
[  178.507598] "nvme-wq"
[  178.507726] ){++++.+}
[  178.508079] , at:
[  178.508173] [<ffffffffa70ad6c2>] process_one_work+0x162/0x6a0
[  178.509004]  #1:
[  178.509265]  (
[  178.509532] (&ctrl->delete_work)
[  178.509795] ){+.+.+.}
[  178.510145] , at:
[  178.510239] [<ffffffffa70ad6c2>] process_one_work+0x162/0x6a0
[  178.511070]
               stack backtrace:
:
[  178.511693] CPU: 5 PID: 135 Comm: kworker/5:1 Tainted: G           OE   4.9.0-rc4-c844263313a8-lb #3
[  178.512974] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.1-1ubuntu1 04/01/2014
[  178.514247] Workqueue: nvme-wq nvme_del_ctrl_work [nvme_tcp]
[  178.515071]  ffffc2668175bae0 ffffffffa7450823 ffffffffa88abd80 ffffffffa88abd80
[  178.516195]  ffffc2668175bb98 ffffffffa70eb012 ffffffffa8d8d90d ffff9c472e9ea700
[  178.517318]  ffff9c472e9ea700 ffff9c4700000000 ffff9c4700007200 ab83be61bec0d50e
[  178.518443] Call Trace:
[  178.518807]  [<ffffffffa7450823>] dump_stack+0x85/0xc2
[  178.519542]  [<ffffffffa70eb012>] __lock_acquire+0x17d2/0x18f0
[  178.520377]  [<ffffffffa75839a7>] ? serial8250_console_putchar+0x27/0x30
[  178.521330]  [<ffffffffa7583980>] ? wait_for_xmitr+0xa0/0xa0
[  178.522174]  [<ffffffffa70ac1eb>] ? flush_work+0x18b/0x2d0
[  178.522975]  [<ffffffffa70eb7cb>] lock_acquire+0x11b/0x220
[  178.523753]  [<ffffffffa70ac206>] ? flush_work+0x1a6/0x2d0
[  178.524535]  [<ffffffffa70ac229>] flush_work+0x1c9/0x2d0
[  178.525291]  [<ffffffffa70ac206>] ? flush_work+0x1a6/0x2d0
[  178.526077]  [<ffffffffa70a9cf0>] ? flush_workqueue_prep_pwqs+0x220/0x220
[  178.527040]  [<ffffffffa70ae7cf>] __cancel_work_timer+0x10f/0x1d0
[  178.527907]  [<ffffffffa70fecb9>] ? vprintk_default+0x29/0x40
[  178.528726]  [<ffffffffa71cb507>] ? printk+0x48/0x50
[  178.529434]  [<ffffffffa70ae8c3>] cancel_delayed_work_sync+0x13/0x20
[  178.530381]  [<ffffffffc042100b>] nvme_stop_ctrl+0x5b/0x70 [nvme_core]
[  178.531314]  [<ffffffffc0403dcc>] nvme_del_ctrl_work+0x2c/0x50 [nvme_tcp]
[  178.532271]  [<ffffffffa70ad741>] process_one_work+0x1e1/0x6a0
[  178.533101]  [<ffffffffa70ad6c2>] ? process_one_work+0x162/0x6a0
[  178.533954]  [<ffffffffa70adc4e>] worker_thread+0x4e/0x490
[  178.534735]  [<ffffffffa70adc00>] ? process_one_work+0x6a0/0x6a0
[  178.535588]  [<ffffffffa70adc00>] ? process_one_work+0x6a0/0x6a0
[  178.536441]  [<ffffffffa70b48cf>] kthread+0xff/0x120
[  178.537149]  [<ffffffffa70b47d0>] ? kthread_park+0x60/0x60
[  178.538094]  [<ffffffffa70b47d0>] ? kthread_park+0x60/0x60
[  178.538900]  [<ffffffffa78e332a>] ret_from_fork+0x2a/0x40

Signed-off-by: Roy Shterman <roys at lightbitslabs.com>
Signed-off-by: Sagi Grimberg <sagi at grimberg.me>
---
 drivers/nvme/host/core.c   | 44 +++++++++++++++++++++++++++++++++++++++-----
 drivers/nvme/host/nvme.h   |  2 ++
 drivers/nvme/host/rdma.c   |  2 +-
 drivers/nvme/target/loop.c |  2 +-
 4 files changed, 43 insertions(+), 7 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d30f21aa0828..d5e8961e08dd 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -65,9 +65,26 @@ static bool streams;
 module_param(streams, bool, 0644);
 MODULE_PARM_DESC(streams, "turn on support for Streams write directives");
 
+/*
+ * nvme_wq - hosts nvme related works that are not reset or delete
+ * nvme_reset_wq - hosts nvme reset works
+ * nvme_delete_wq - hosts nvme delete works
+ *
+ * nvme_wq will host works such are scan, aen handling, fw activation,
+ * keep-alive error recovery, periodic reconnects etc. nvme_reset_wq
+ * runs reset works which also flush works hosted on nvme_wq for
+ * serialization purposes. nvme_delete_wq host controller deletion
+ * works which flush reset works for serialization.
+ */
 struct workqueue_struct *nvme_wq;
 EXPORT_SYMBOL_GPL(nvme_wq);
 
+struct workqueue_struct *nvme_reset_wq;
+EXPORT_SYMBOL_GPL(nvme_reset_wq);
+
+struct workqueue_struct *nvme_delete_wq;
+EXPORT_SYMBOL_GPL(nvme_delete_wq);
+
 static DEFINE_IDA(nvme_subsystems_ida);
 static LIST_HEAD(nvme_subsystems);
 static DEFINE_MUTEX(nvme_subsystems_lock);
@@ -89,7 +106,7 @@ int nvme_reset_ctrl(struct nvme_ctrl *ctrl)
 {
 	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING))
 		return -EBUSY;
-	if (!queue_work(nvme_wq, &ctrl->reset_work))
+	if (!queue_work(nvme_reset_wq, &ctrl->reset_work))
 		return -EBUSY;
 	return 0;
 }
@@ -123,7 +140,7 @@ int nvme_delete_ctrl(struct nvme_ctrl *ctrl)
 {
 	if (!nvme_change_ctrl_state(ctrl, NVME_CTRL_DELETING))
 		return -EBUSY;
-	if (!queue_work(nvme_wq, &ctrl->delete_work))
+	if (!queue_work(nvme_delete_wq, &ctrl->delete_work))
 		return -EBUSY;
 	return 0;
 }
@@ -3524,16 +3541,26 @@ EXPORT_SYMBOL_GPL(nvme_reinit_tagset);
 
 int __init nvme_core_init(void)
 {
-	int result;
+	int result = -ENOMEM;
 
 	nvme_wq = alloc_workqueue("nvme-wq",
 			WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
 	if (!nvme_wq)
-		return -ENOMEM;
+		goto out;
+
+	nvme_reset_wq = alloc_workqueue("nvme-reset-wq",
+			WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
+	if (!nvme_reset_wq)
+		goto destroy_wq;
+
+	nvme_delete_wq = alloc_workqueue("nvme-delete-wq",
+			WQ_UNBOUND | WQ_MEM_RECLAIM | WQ_SYSFS, 0);
+	if (!nvme_delete_wq)
+		goto destroy_reset_wq;
 
 	result = alloc_chrdev_region(&nvme_chr_devt, 0, NVME_MINORS, "nvme");
 	if (result < 0)
-		goto destroy_wq;
+		goto destroy_delete_wq;
 
 	nvme_class = class_create(THIS_MODULE, "nvme");
 	if (IS_ERR(nvme_class)) {
@@ -3552,8 +3579,13 @@ int __init nvme_core_init(void)
 	class_destroy(nvme_class);
 unregister_chrdev:
 	unregister_chrdev_region(nvme_chr_devt, NVME_MINORS);
+destroy_delete_wq:
+	destroy_workqueue(nvme_delete_wq);
+destroy_reset_wq:
+	destroy_workqueue(nvme_reset_wq);
 destroy_wq:
 	destroy_workqueue(nvme_wq);
+out:
 	return result;
 }
 
@@ -3563,6 +3595,8 @@ void nvme_core_exit(void)
 	class_destroy(nvme_subsys_class);
 	class_destroy(nvme_class);
 	unregister_chrdev_region(nvme_chr_devt, NVME_MINORS);
+	destroy_workqueue(nvme_delete_wq);
+	destroy_workqueue(nvme_reset_wq);
 	destroy_workqueue(nvme_wq);
 }
 
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 6097091bab42..488be272cf5d 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -32,6 +32,8 @@ extern unsigned int admin_timeout;
 #define NVME_KATO_GRACE		10
 
 extern struct workqueue_struct *nvme_wq;
+extern struct workqueue_struct *nvme_reset_wq;
+extern struct workqueue_struct *nvme_delete_wq;
 
 enum {
 	NVME_NS_LBA		= 0,
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index d49b1e74f304..a71ed67cd9a5 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -2041,7 +2041,7 @@ static void nvme_rdma_remove_one(struct ib_device *ib_device, void *client_data)
 	}
 	mutex_unlock(&nvme_rdma_ctrl_mutex);
 
-	flush_workqueue(nvme_wq);
+	flush_workqueue(nvme_delete_wq);
 }
 
 static struct ib_client nvme_rdma_ib_client = {
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
index fdfcc961029f..7991ec3a17db 100644
--- a/drivers/nvme/target/loop.c
+++ b/drivers/nvme/target/loop.c
@@ -717,7 +717,7 @@ static void __exit nvme_loop_cleanup_module(void)
 		nvme_delete_ctrl(&ctrl->ctrl);
 	mutex_unlock(&nvme_loop_ctrl_mutex);
 
-	flush_workqueue(nvme_wq);
+	flush_workqueue(nvme_delete_wq);
 }
 
 module_init(nvme_loop_init_module);
-- 
2.14.1

[PATCH resend 0/3] couple of nvme patches resend

[Christoph Hellwig]

On Sun, Jan 14, 2018@12:38:59PM +0200, Sagi Grimberg wrote:
> Seems these got positive feedback (informally) but were left behind..

Thanks, applied to nvme-4.6.

[PATCH resend 2/3] nvme-pci: allocate device queues storage space at probe

[Keith Busch]

On Sun, Jan 14, 2018@12:39:01PM +0200, Sagi Grimberg wrote:
> @@ -1590,14 +1580,12 @@ static int nvme_pci_configure_admin_queue(struct nvme_dev *dev)
>  	if (result < 0)
>  		return result;
>  
> -	nvmeq = dev->queues[0];
> -	if (!nvmeq) {
> -		nvmeq = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH,
> -					dev_to_node(dev->dev));
> -		if (!nvmeq)
> -			return -ENOMEM;
> -	}
> +	result = nvme_alloc_queue(dev, 0, NVME_AQ_DEPTH,
> +			dev_to_node(dev->dev));
> +	if (result)
> +		return result;
>  
> +	nvmeq = &dev->queues[0];
>  	aqa = nvmeq->q_depth - 1;
>  	aqa |= aqa << 16;

This is reallocting the admin queue on each reset, leaking the previous
allocation's SQ/CQ memory, then creates an incorrect queue_count. This
was already applied, so I'll send a quick fix.