linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] scsi_dh_rdac: Fix for unbalanced reference count
@ 2012-02-02 15:21 Moger, Babu
  2012-02-02 19:43 ` Chandra Seetharaman
  0 siblings, 1 reply; 3+ messages in thread
From: Moger, Babu @ 2012-02-02 15:21 UTC (permalink / raw)
  To: linux-kernel; +Cc: device-mapper development, Mike Snitzer

Resubmitting it again(Probably last one had some format issues).

This patch fixes an unbalanced refcount issue.

Elevating the lock for both kref_put and also for controller node deletion.
Previously, controller deletion was protected but the not the kref_put. This was causing
the other thread to pick up the controller structure which was already kref'd zero.

This was causing the following BUG_ON and also sometimes panic.

WARNING: at lib/kref.c:43 kref_get+0x2d/0x30() (Not tainted)
Hardware name: IBM System x3655 -[7985AC1]-
Modules linked in: fuse scsi_dh_rdac autofs4 nfs lockd fscache nfs_acl
auth_rpcgss sunrpc 8021q garp stp llc ipv6 ib_srp(U) scsi_transport_srp
scsi_tgt ib_cm(U) ib_sa(U) ib_uverbs(U) ib_umad(U) mlx4_ib(U) mlx4_core(U)
ib_mthca(U) ib_mad(U) ib_core(U) dm_mirror dm_region_hash dm_log dm_round_robin
dm_multipath uinput bnx2 ses enclosure sg ibmpex ibmaem ipmi_msghandler
serio_raw k8temp hwmon amd64_edac_mod edac_core edac_mce_amd shpchp i2c_piix4
ext4 mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif sata_svw pata_acpi ata_generic
pata_serverworks aacraid radeon ttm drm_kms_helper drm i2c_algo_bit i2c_core
dm_mod [last unloaded: freq_table]
Pid: 13735, comm: srp_daemon Not tainted 2.6.32-71.el6.x86_64 #1
Call Trace:
[<ffffffff8106b857>] warn_slowpath_common+0x87/0xc0
[<ffffffff8106b8aa>] warn_slowpath_null+0x1a/0x20
[<ffffffff8125c39d>] kref_get+0x2d/0x30
[<ffffffffa01b4029>] rdac_bus_attach+0x459/0x580 [scsi_dh_rdac]
[<ffffffff8135232a>] scsi_dh_handler_attach+0x2a/0x80
[<ffffffff81352c7b>] scsi_dh_notifier+0x9b/0xa0
[<ffffffff814cd7a5>] notifier_call_chain+0x55/0x80
[<ffffffff8109711a>] __blocking_notifier_call_chain+0x5a/0x80
[<ffffffff81097156>] blocking_notifier_call_chain+0x16/0x20
[<ffffffff8132bec5>] device_add+0x515/0x640
[<ffffffff813329e4>] ? attribute_container_device_trigger+0xc4/0xe0
[<ffffffff8134f659>] scsi_sysfs_add_sdev+0x89/0x2c0
[<ffffffff8134d096>] scsi_probe_and_add_lun+0xea6/0xed0
[<ffffffff8134beb2>] ? scsi_alloc_target+0x292/0x2d0
[<ffffffff8134d1e1>] __scsi_scan_target+0x121/0x750
[<ffffffff811df806>] ? sysfs_create_file+0x26/0x30
[<ffffffff8132b759>] ? device_create_file+0x19/0x20
[<ffffffff81332838>] ? attribute_container_add_attrs+0x78/0x90
[<ffffffff814b008c>] ? klist_next+0x4c/0xf0
[<ffffffff81332e30>] ? transport_configure+0x0/0x20
[<ffffffff813329e4>] ? attribute_container_device_trigger+0xc4/0xe0
[<ffffffff8134df40>] scsi_scan_target+0xd0/0xe0
[<ffffffffa02f053a>] srp_create_target+0x75a/0x890 [ib_srp]
[<ffffffff8132a130>] dev_attr_store+0x20/0x30
[<ffffffff811df145>] sysfs_write_file+0xe5/0x170
[<ffffffff8116c818>] vfs_write+0xb8/0x1a0
[<ffffffff810d40a2>] ? audit_syscall_entry+0x272/0x2a0
[<ffffffff8116d251>] sys_write+0x51/0x90
[<ffffffff81013172>] system_call_fastpath+0x16/0x1b


Signed-off-by: Babu Moger <babu.moger@netapp.com>
Acked-by: Mike Snitzer <snitzer@redhat.com>
---
--- linux-3.3-rc1-new/drivers/scsi/device_handler/scsi_dh_rdac.c.orig	2012-01-19 17:04:48.000000000 -0600
+++ linux-3.3-rc1-new/drivers/scsi/device_handler/scsi_dh_rdac.c	2012-02-01 10:50:31.000000000 -0600
@@ -364,10 +364,7 @@ static void release_controller(struct kr
 	struct rdac_controller *ctlr;
 	ctlr = container_of(kref, struct rdac_controller, kref);
 
-	flush_workqueue(kmpath_rdacd);
-	spin_lock(&list_lock);
 	list_del(&ctlr->node);
-	spin_unlock(&list_lock);
 	kfree(ctlr);
 }
 
@@ -376,20 +373,17 @@ static struct rdac_controller *get_contr
 {
 	struct rdac_controller *ctlr, *tmp;
 
-	spin_lock(&list_lock);
-
 	list_for_each_entry(tmp, &ctlr_list, node) {
 		if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
 			  (tmp->index == index) &&
 			  (tmp->host == sdev->host)) {
 			kref_get(&tmp->kref);
-			spin_unlock(&list_lock);
 			return tmp;
 		}
 	}
 	ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
 	if (!ctlr)
-		goto done;
+		return NULL;
 
 	/* initialize fields of controller */
 	memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
@@ -405,8 +399,7 @@ static struct rdac_controller *get_contr
 	INIT_WORK(&ctlr->ms_work, send_mode_select);
 	INIT_LIST_HEAD(&ctlr->ms_head);
 	list_add(&ctlr->node, &ctlr_list);
-done:
-	spin_unlock(&list_lock);
+
 	return ctlr;
 }
 
@@ -517,9 +510,12 @@ static int initialize_controller(struct
 			index = 0;
 		else
 			index = 1;
+
+		spin_lock(&list_lock);
 		h->ctlr = get_controller(index, array_name, array_id, sdev);
 		if (!h->ctlr)
 			err = SCSI_DH_RES_TEMP_UNAVAIL;
+		spin_unlock(&list_lock);
 	}
 	return err;
 }
@@ -906,7 +902,9 @@ static int rdac_bus_attach(struct scsi_d
 	return 0;
 
 clean_ctlr:
+	spin_lock(&list_lock);
 	kref_put(&h->ctlr->kref, release_controller);
+	spin_unlock(&list_lock);
 
 failed:
 	kfree(scsi_dh_data);
@@ -921,14 +919,19 @@ static void rdac_bus_detach( struct scsi
 	struct rdac_dh_data *h;
 	unsigned long flags;
 
-	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 	scsi_dh_data = sdev->scsi_dh_data;
+	h = (struct rdac_dh_data *) scsi_dh_data->buf;
+	if (h->ctlr && h->ctlr->ms_queued)
+		flush_workqueue(kmpath_rdacd);
+
+	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
 	sdev->scsi_dh_data = NULL;
 	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
 
-	h = (struct rdac_dh_data *) scsi_dh_data->buf;
+	spin_lock(&list_lock);
 	if (h->ctlr)
 		kref_put(&h->ctlr->kref, release_controller);
+	spin_unlock(&list_lock);
 	kfree(scsi_dh_data);
 	module_put(THIS_MODULE);
 	sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);



^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH] scsi_dh_rdac: Fix for unbalanced reference count
  2012-02-02 15:21 [PATCH] scsi_dh_rdac: Fix for unbalanced reference count Moger, Babu
@ 2012-02-02 19:43 ` Chandra Seetharaman
  2012-02-22 17:53   ` Moger, Babu
  0 siblings, 1 reply; 3+ messages in thread
From: Chandra Seetharaman @ 2012-02-02 19:43 UTC (permalink / raw)
  To: Moger, Babu; +Cc: linux-kernel, device-mapper development, Mike Snitzer

Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com>

On Thu, 2012-02-02 at 15:21 +0000, Moger, Babu wrote:
> Resubmitting it again(Probably last one had some format issues).
> 
> This patch fixes an unbalanced refcount issue.
> 
> Elevating the lock for both kref_put and also for controller node deletion.
> Previously, controller deletion was protected but the not the kref_put. This was causing
> the other thread to pick up the controller structure which was already kref'd zero.
> 
> This was causing the following BUG_ON and also sometimes panic.
> 
> WARNING: at lib/kref.c:43 kref_get+0x2d/0x30() (Not tainted)
> Hardware name: IBM System x3655 -[7985AC1]-
> Modules linked in: fuse scsi_dh_rdac autofs4 nfs lockd fscache nfs_acl
> auth_rpcgss sunrpc 8021q garp stp llc ipv6 ib_srp(U) scsi_transport_srp
> scsi_tgt ib_cm(U) ib_sa(U) ib_uverbs(U) ib_umad(U) mlx4_ib(U) mlx4_core(U)
> ib_mthca(U) ib_mad(U) ib_core(U) dm_mirror dm_region_hash dm_log dm_round_robin
> dm_multipath uinput bnx2 ses enclosure sg ibmpex ibmaem ipmi_msghandler
> serio_raw k8temp hwmon amd64_edac_mod edac_core edac_mce_amd shpchp i2c_piix4
> ext4 mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif sata_svw pata_acpi ata_generic
> pata_serverworks aacraid radeon ttm drm_kms_helper drm i2c_algo_bit i2c_core
> dm_mod [last unloaded: freq_table]
> Pid: 13735, comm: srp_daemon Not tainted 2.6.32-71.el6.x86_64 #1
> Call Trace:
> [<ffffffff8106b857>] warn_slowpath_common+0x87/0xc0
> [<ffffffff8106b8aa>] warn_slowpath_null+0x1a/0x20
> [<ffffffff8125c39d>] kref_get+0x2d/0x30
> [<ffffffffa01b4029>] rdac_bus_attach+0x459/0x580 [scsi_dh_rdac]
> [<ffffffff8135232a>] scsi_dh_handler_attach+0x2a/0x80
> [<ffffffff81352c7b>] scsi_dh_notifier+0x9b/0xa0
> [<ffffffff814cd7a5>] notifier_call_chain+0x55/0x80
> [<ffffffff8109711a>] __blocking_notifier_call_chain+0x5a/0x80
> [<ffffffff81097156>] blocking_notifier_call_chain+0x16/0x20
> [<ffffffff8132bec5>] device_add+0x515/0x640
> [<ffffffff813329e4>] ? attribute_container_device_trigger+0xc4/0xe0
> [<ffffffff8134f659>] scsi_sysfs_add_sdev+0x89/0x2c0
> [<ffffffff8134d096>] scsi_probe_and_add_lun+0xea6/0xed0
> [<ffffffff8134beb2>] ? scsi_alloc_target+0x292/0x2d0
> [<ffffffff8134d1e1>] __scsi_scan_target+0x121/0x750
> [<ffffffff811df806>] ? sysfs_create_file+0x26/0x30
> [<ffffffff8132b759>] ? device_create_file+0x19/0x20
> [<ffffffff81332838>] ? attribute_container_add_attrs+0x78/0x90
> [<ffffffff814b008c>] ? klist_next+0x4c/0xf0
> [<ffffffff81332e30>] ? transport_configure+0x0/0x20
> [<ffffffff813329e4>] ? attribute_container_device_trigger+0xc4/0xe0
> [<ffffffff8134df40>] scsi_scan_target+0xd0/0xe0
> [<ffffffffa02f053a>] srp_create_target+0x75a/0x890 [ib_srp]
> [<ffffffff8132a130>] dev_attr_store+0x20/0x30
> [<ffffffff811df145>] sysfs_write_file+0xe5/0x170
> [<ffffffff8116c818>] vfs_write+0xb8/0x1a0
> [<ffffffff810d40a2>] ? audit_syscall_entry+0x272/0x2a0
> [<ffffffff8116d251>] sys_write+0x51/0x90
> [<ffffffff81013172>] system_call_fastpath+0x16/0x1b
> 
> 
> Signed-off-by: Babu Moger <babu.moger@netapp.com>
> Acked-by: Mike Snitzer <snitzer@redhat.com>
> ---
> --- linux-3.3-rc1-new/drivers/scsi/device_handler/scsi_dh_rdac.c.orig	2012-01-19 17:04:48.000000000 -0600
> +++ linux-3.3-rc1-new/drivers/scsi/device_handler/scsi_dh_rdac.c	2012-02-01 10:50:31.000000000 -0600
> @@ -364,10 +364,7 @@ static void release_controller(struct kr
>  	struct rdac_controller *ctlr;
>  	ctlr = container_of(kref, struct rdac_controller, kref);
> 
> -	flush_workqueue(kmpath_rdacd);
> -	spin_lock(&list_lock);
>  	list_del(&ctlr->node);
> -	spin_unlock(&list_lock);
>  	kfree(ctlr);
>  }
> 
> @@ -376,20 +373,17 @@ static struct rdac_controller *get_contr
>  {
>  	struct rdac_controller *ctlr, *tmp;
> 
> -	spin_lock(&list_lock);
> -
>  	list_for_each_entry(tmp, &ctlr_list, node) {
>  		if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0) &&
>  			  (tmp->index == index) &&
>  			  (tmp->host == sdev->host)) {
>  			kref_get(&tmp->kref);
> -			spin_unlock(&list_lock);
>  			return tmp;
>  		}
>  	}
>  	ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
>  	if (!ctlr)
> -		goto done;
> +		return NULL;
> 
>  	/* initialize fields of controller */
>  	memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
> @@ -405,8 +399,7 @@ static struct rdac_controller *get_contr
>  	INIT_WORK(&ctlr->ms_work, send_mode_select);
>  	INIT_LIST_HEAD(&ctlr->ms_head);
>  	list_add(&ctlr->node, &ctlr_list);
> -done:
> -	spin_unlock(&list_lock);
> +
>  	return ctlr;
>  }
> 
> @@ -517,9 +510,12 @@ static int initialize_controller(struct
>  			index = 0;
>  		else
>  			index = 1;
> +
> +		spin_lock(&list_lock);
>  		h->ctlr = get_controller(index, array_name, array_id, sdev);
>  		if (!h->ctlr)
>  			err = SCSI_DH_RES_TEMP_UNAVAIL;
> +		spin_unlock(&list_lock);
>  	}
>  	return err;
>  }
> @@ -906,7 +902,9 @@ static int rdac_bus_attach(struct scsi_d
>  	return 0;
> 
>  clean_ctlr:
> +	spin_lock(&list_lock);
>  	kref_put(&h->ctlr->kref, release_controller);
> +	spin_unlock(&list_lock);
> 
>  failed:
>  	kfree(scsi_dh_data);
> @@ -921,14 +919,19 @@ static void rdac_bus_detach( struct scsi
>  	struct rdac_dh_data *h;
>  	unsigned long flags;
> 
> -	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
>  	scsi_dh_data = sdev->scsi_dh_data;
> +	h = (struct rdac_dh_data *) scsi_dh_data->buf;
> +	if (h->ctlr && h->ctlr->ms_queued)
> +		flush_workqueue(kmpath_rdacd);
> +
> +	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
>  	sdev->scsi_dh_data = NULL;
>  	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
> 
> -	h = (struct rdac_dh_data *) scsi_dh_data->buf;
> +	spin_lock(&list_lock);
>  	if (h->ctlr)
>  		kref_put(&h->ctlr->kref, release_controller);
> +	spin_unlock(&list_lock);
>  	kfree(scsi_dh_data);
>  	module_put(THIS_MODULE);
>  	sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 



^ permalink raw reply	[flat|nested] 3+ messages in thread
* RE: [PATCH] scsi_dh_rdac: Fix for unbalanced reference count
  2012-02-02 19:43 ` Chandra Seetharaman
@ 2012-02-22 17:53   ` Moger, Babu
  0 siblings, 0 replies; 3+ messages in thread
From: Moger, Babu @ 2012-02-22 17:53 UTC (permalink / raw)
  To: linux-scsi, JBottomley
  Cc: linux-kernel, device-mapper development, Mike Snitzer, sekharan

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset="utf-8", Size: 6921 bytes --]

James, Can you please pick this up for the next update.

> -----Original Message-----
> From: Chandra Seetharaman [mailto:sekharan@us.ibm.com]
> Sent: Thursday, February 02, 2012 1:44 PM
> To: Moger, Babu
> Cc: linux-kernel@vger.kernel.org; device-mapper development; Mike
> Snitzer
> Subject: Re: [PATCH] scsi_dh_rdac: Fix for unbalanced reference count
> 
> Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com>
> 
> On Thu, 2012-02-02 at 15:21 +0000, Moger, Babu wrote:
> > Resubmitting it again(Probably last one had some format issues).
> >
> > This patch fixes an unbalanced refcount issue.
> >
> > Elevating the lock for both kref_put and also for controller node
> deletion.
> > Previously, controller deletion was protected but the not the
> kref_put. This was causing
> > the other thread to pick up the controller structure which was
> already kref'd zero.
> >
> > This was causing the following BUG_ON and also sometimes panic.
> >
> > WARNING: at lib/kref.c:43 kref_get+0x2d/0x30() (Not tainted)
> > Hardware name: IBM System x3655 -[7985AC1]-
> > Modules linked in: fuse scsi_dh_rdac autofs4 nfs lockd fscache
> nfs_acl
> > auth_rpcgss sunrpc 8021q garp stp llc ipv6 ib_srp(U)
> scsi_transport_srp
> > scsi_tgt ib_cm(U) ib_sa(U) ib_uverbs(U) ib_umad(U) mlx4_ib(U)
> mlx4_core(U)
> > ib_mthca(U) ib_mad(U) ib_core(U) dm_mirror dm_region_hash dm_log
> dm_round_robin
> > dm_multipath uinput bnx2 ses enclosure sg ibmpex ibmaem
> ipmi_msghandler
> > serio_raw k8temp hwmon amd64_edac_mod edac_core edac_mce_amd shpchp
> i2c_piix4
> > ext4 mbcache jbd2 sr_mod cdrom sd_mod crc_t10dif sata_svw pata_acpi
> ata_generic
> > pata_serverworks aacraid radeon ttm drm_kms_helper drm i2c_algo_bit
> i2c_core
> > dm_mod [last unloaded: freq_table]
> > Pid: 13735, comm: srp_daemon Not tainted 2.6.32-71.el6.x86_64 #1
> > Call Trace:
> > [<ffffffff8106b857>] warn_slowpath_common+0x87/0xc0
> > [<ffffffff8106b8aa>] warn_slowpath_null+0x1a/0x20
> > [<ffffffff8125c39d>] kref_get+0x2d/0x30
> > [<ffffffffa01b4029>] rdac_bus_attach+0x459/0x580 [scsi_dh_rdac]
> > [<ffffffff8135232a>] scsi_dh_handler_attach+0x2a/0x80
> > [<ffffffff81352c7b>] scsi_dh_notifier+0x9b/0xa0
> > [<ffffffff814cd7a5>] notifier_call_chain+0x55/0x80
> > [<ffffffff8109711a>] __blocking_notifier_call_chain+0x5a/0x80
> > [<ffffffff81097156>] blocking_notifier_call_chain+0x16/0x20
> > [<ffffffff8132bec5>] device_add+0x515/0x640
> > [<ffffffff813329e4>] ? attribute_container_device_trigger+0xc4/0xe0
> > [<ffffffff8134f659>] scsi_sysfs_add_sdev+0x89/0x2c0
> > [<ffffffff8134d096>] scsi_probe_and_add_lun+0xea6/0xed0
> > [<ffffffff8134beb2>] ? scsi_alloc_target+0x292/0x2d0
> > [<ffffffff8134d1e1>] __scsi_scan_target+0x121/0x750
> > [<ffffffff811df806>] ? sysfs_create_file+0x26/0x30
> > [<ffffffff8132b759>] ? device_create_file+0x19/0x20
> > [<ffffffff81332838>] ? attribute_container_add_attrs+0x78/0x90
> > [<ffffffff814b008c>] ? klist_next+0x4c/0xf0
> > [<ffffffff81332e30>] ? transport_configure+0x0/0x20
> > [<ffffffff813329e4>] ? attribute_container_device_trigger+0xc4/0xe0
> > [<ffffffff8134df40>] scsi_scan_target+0xd0/0xe0
> > [<ffffffffa02f053a>] srp_create_target+0x75a/0x890 [ib_srp]
> > [<ffffffff8132a130>] dev_attr_store+0x20/0x30
> > [<ffffffff811df145>] sysfs_write_file+0xe5/0x170
> > [<ffffffff8116c818>] vfs_write+0xb8/0x1a0
> > [<ffffffff810d40a2>] ? audit_syscall_entry+0x272/0x2a0
> > [<ffffffff8116d251>] sys_write+0x51/0x90
> > [<ffffffff81013172>] system_call_fastpath+0x16/0x1b
> >
> >
> > Signed-off-by: Babu Moger <babu.moger@netapp.com>
> > Acked-by: Mike Snitzer <snitzer@redhat.com>
> > ---
> > --- linux-3.3-rc1-new/drivers/scsi/device_handler/scsi_dh_rdac.c.orig
> 	2012-01-19 17:04:48.000000000 -0600
> > +++ linux-3.3-rc1-new/drivers/scsi/device_handler/scsi_dh_rdac.c
> 	2012-02-01 10:50:31.000000000 -0600
> > @@ -364,10 +364,7 @@ static void release_controller(struct kr
> >  	struct rdac_controller *ctlr;
> >  	ctlr = container_of(kref, struct rdac_controller, kref);
> >
> > -	flush_workqueue(kmpath_rdacd);
> > -	spin_lock(&list_lock);
> >  	list_del(&ctlr->node);
> > -	spin_unlock(&list_lock);
> >  	kfree(ctlr);
> >  }
> >
> > @@ -376,20 +373,17 @@ static struct rdac_controller *get_contr
> >  {
> >  	struct rdac_controller *ctlr, *tmp;
> >
> > -	spin_lock(&list_lock);
> > -
> >  	list_for_each_entry(tmp, &ctlr_list, node) {
> >  		if ((memcmp(tmp->array_id, array_id, UNIQUE_ID_LEN) == 0)
> &&
> >  			  (tmp->index == index) &&
> >  			  (tmp->host == sdev->host)) {
> >  			kref_get(&tmp->kref);
> > -			spin_unlock(&list_lock);
> >  			return tmp;
> >  		}
> >  	}
> >  	ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC);
> >  	if (!ctlr)
> > -		goto done;
> > +		return NULL;
> >
> >  	/* initialize fields of controller */
> >  	memcpy(ctlr->array_id, array_id, UNIQUE_ID_LEN);
> > @@ -405,8 +399,7 @@ static struct rdac_controller *get_contr
> >  	INIT_WORK(&ctlr->ms_work, send_mode_select);
> >  	INIT_LIST_HEAD(&ctlr->ms_head);
> >  	list_add(&ctlr->node, &ctlr_list);
> > -done:
> > -	spin_unlock(&list_lock);
> > +
> >  	return ctlr;
> >  }
> >
> > @@ -517,9 +510,12 @@ static int initialize_controller(struct
> >  			index = 0;
> >  		else
> >  			index = 1;
> > +
> > +		spin_lock(&list_lock);
> >  		h->ctlr = get_controller(index, array_name, array_id,
> sdev);
> >  		if (!h->ctlr)
> >  			err = SCSI_DH_RES_TEMP_UNAVAIL;
> > +		spin_unlock(&list_lock);
> >  	}
> >  	return err;
> >  }
> > @@ -906,7 +902,9 @@ static int rdac_bus_attach(struct scsi_d
> >  	return 0;
> >
> >  clean_ctlr:
> > +	spin_lock(&list_lock);
> >  	kref_put(&h->ctlr->kref, release_controller);
> > +	spin_unlock(&list_lock);
> >
> >  failed:
> >  	kfree(scsi_dh_data);
> > @@ -921,14 +919,19 @@ static void rdac_bus_detach( struct scsi
> >  	struct rdac_dh_data *h;
> >  	unsigned long flags;
> >
> > -	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
> >  	scsi_dh_data = sdev->scsi_dh_data;
> > +	h = (struct rdac_dh_data *) scsi_dh_data->buf;
> > +	if (h->ctlr && h->ctlr->ms_queued)
> > +		flush_workqueue(kmpath_rdacd);
> > +
> > +	spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
> >  	sdev->scsi_dh_data = NULL;
> >  	spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
> >
> > -	h = (struct rdac_dh_data *) scsi_dh_data->buf;
> > +	spin_lock(&list_lock);
> >  	if (h->ctlr)
> >  		kref_put(&h->ctlr->kref, release_controller);
> > +	spin_unlock(&list_lock);
> >  	kfree(scsi_dh_data);
> >  	module_put(THIS_MODULE);
> >  	sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", RDAC_NAME);
> >
> >
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-scsi"
> in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> >
> 

ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-02-22 17:54 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-02-02 15:21 [PATCH] scsi_dh_rdac: Fix for unbalanced reference count Moger, Babu
2012-02-02 19:43 ` Chandra Seetharaman
2012-02-22 17:53   ` Moger, Babu

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).