Re: [PATCH 8/8] target: display 'write_protect' attribute for demo-mode LUNs

2015-06-19 Thread Hannes Reinecke
On 06/19/2015 08:51 AM, Christoph Hellwig wrote:
> On Thu, Jun 18, 2015 at 11:43:42AM +0200, Hannes Reinecke wrote:
>> When LUNs are mapped with a demo-mode initiator we're missing
>> the 'write_protect' attribute to set a LUN read-only.
> 
> I don't think it's a good idea as-is.  The target core clearly
> differenciates between demo mode and production mode read only, and some
> drivers already expose attributes for these.
> 
> I have a big series in progress to clean the mess around this area
> up.  So for now please don't add anything here, it should become much
> simpler after my changes, and I might be able to incorporate something
> like this after the main series.
> 
I've done this particular patch to simulate write-protected LUNs via
tcm_loop. As the hooks already had been there I thought this to be
the 'cleanest' approach.

Of course, if you have other suggestions on how this should be
achieved I'm happy to try this.

Cheers,

Hannes
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SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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Re: [PATCH 8/8] target: display 'write_protect' attribute for demo-mode LUNs

2015-06-18 Thread Christoph Hellwig
On Thu, Jun 18, 2015 at 11:43:42AM +0200, Hannes Reinecke wrote:
> When LUNs are mapped with a demo-mode initiator we're missing
> the 'write_protect' attribute to set a LUN read-only.

I don't think it's a good idea as-is.  The target core clearly
differenciates between demo mode and production mode read only, and some
drivers already expose attributes for these.

I have a big series in progress to clean the mess around this area
up.  So for now please don't add anything here, it should become much
simpler after my changes, and I might be able to incorporate something
like this after the main series.
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[PATCH 8/8] target: display 'write_protect' attribute for demo-mode LUNs

2015-06-18 Thread Hannes Reinecke
When LUNs are mapped with a demo-mode initiator we're missing
the 'write_protect' attribute to set a LUN read-only.

Signed-off-by: Hannes Reinecke 
---
 drivers/target/target_core_device.c  | 27 ++
 drivers/target/target_core_fabric_configfs.c | 42 
 drivers/target/target_core_internal.h|  1 +
 3 files changed, 70 insertions(+)

diff --git a/drivers/target/target_core_device.c 
b/drivers/target/target_core_device.c
index 88d6070..3e17070 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -271,6 +271,33 @@ void core_update_device_list_access(
mutex_unlock(&nacl->lun_entry_mutex);
 }
 
+void core_update_lun_access(
+   struct se_lun *lun,
+   u32 lun_access)
+{
+   struct se_dev_entry *deve;
+
+   if (lun_access == TRANSPORT_LUNFLAGS_READ_ONLY) {
+   lun->lun_access &= ~TRANSPORT_LUNFLAGS_READ_WRITE;
+   lun->lun_access |= TRANSPORT_LUNFLAGS_READ_ONLY;
+   } else {
+   lun->lun_access &= ~TRANSPORT_LUNFLAGS_READ_ONLY;
+   lun->lun_access |= TRANSPORT_LUNFLAGS_READ_WRITE;
+   }
+
+   spin_lock_bh(&lun->lun_deve_lock);
+   list_for_each_entry(deve, &lun->lun_deve_list, lun_link) {
+   if (lun_access & TRANSPORT_LUNFLAGS_READ_WRITE) {
+   deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_ONLY;
+   deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_WRITE;
+   } else {
+   deve->lun_flags &= ~TRANSPORT_LUNFLAGS_READ_WRITE;
+   deve->lun_flags |= TRANSPORT_LUNFLAGS_READ_ONLY;
+   }
+   }
+   spin_unlock_bh(&lun->lun_deve_lock);
+}
+
 /*
  * Called with rcu_read_lock or nacl->device_list_lock held.
  */
diff --git a/drivers/target/target_core_fabric_configfs.c 
b/drivers/target/target_core_fabric_configfs.c
index 6cfee59..299b4b5 100644
--- a/drivers/target/target_core_fabric_configfs.c
+++ b/drivers/target/target_core_fabric_configfs.c
@@ -726,12 +726,54 @@ static ssize_t 
target_fabric_port_store_attr_alua_tg_pt_write_md(
 
 TCM_PORT_ATTR(alua_tg_pt_write_md, S_IRUGO | S_IWUSR);
 
+static ssize_t target_fabric_port_show_attr_write_protect(
+   struct se_lun *lun,
+   char *page)
+{
+   ssize_t len = 0;
+
+   if (!lun || !lun->lun_se_dev)
+   return -ENODEV;
+
+   len = sprintf(page, "%d\n",
+ (lun->lun_access & TRANSPORT_LUNFLAGS_READ_ONLY) ? 1 : 0);
+
+   return len;
+}
+
+static ssize_t target_fabric_port_store_attr_write_protect(
+   struct se_lun *lun,
+   const char *page,
+   size_t count)
+{
+   unsigned long op;
+   int ret;
+
+   if (!lun || !lun->lun_se_dev)
+   return -ENODEV;
+
+   ret = kstrtoul(page, 0, &op);
+   if (ret)
+   return ret;
+
+   if ((op != 1) && (op != 0))
+   return -EINVAL;
+
+   core_update_lun_access(lun, (op) ?
+  TRANSPORT_LUNFLAGS_READ_ONLY :
+  TRANSPORT_LUNFLAGS_READ_WRITE);
+
+   return count;
+
+}
+TCM_PORT_ATTR(write_protect, S_IRUGO | S_IWUSR);
 
 static struct configfs_attribute *target_fabric_port_attrs[] = {
&target_fabric_port_alua_tg_pt_gp.attr,
&target_fabric_port_alua_tg_pt_offline.attr,
&target_fabric_port_alua_tg_pt_status.attr,
&target_fabric_port_alua_tg_pt_write_md.attr,
+   &target_fabric_port_write_protect.attr,
NULL,
 };
 
diff --git a/drivers/target/target_core_internal.h 
b/drivers/target/target_core_internal.h
index 5111789..69a57a4 100644
--- a/drivers/target/target_core_internal.h
+++ b/drivers/target/target_core_internal.h
@@ -36,6 +36,7 @@ void  core_clear_lun_from_tpg(struct se_lun *, struct 
se_portal_group *);
 intcore_dev_add_lun(struct se_portal_group *, struct se_device *,
struct se_lun *lun);
 void   core_dev_del_lun(struct se_portal_group *, struct se_lun *);
+void   core_update_lun_access(struct se_lun *, u32);
 struct se_lun_acl *core_dev_init_initiator_node_lun_acl(struct se_portal_group 
*,
struct se_node_acl *, u64, int *);
 intcore_dev_add_initiator_node_lun_acl(struct se_portal_group *,
-- 
1.8.5.2

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