Re: [PATCH] tcmu: Allow reconfig to handle multiple attributes

[Bryant G. Ly]

On 1/10/18 12:26 PM, Mike Christie wrote:

> On 01/04/2018 10:11 AM, Bryant G. Ly wrote:
>> This patch allows for multiple attributes to be reconfigured
>> and handled all in one call as compared to multiple netlinks.
>>
>> Example:
>> set attribute dev_reconfig=dev_config=fbo//home/path:dev_size=2147483648
>>
> I know I suggested this, but I think I was wrong. If we have to support
> other apps that work in reverse to targetcli+tcmu-runner where the
> tcmu-runner equivalent app sets things up then contacts the kernel,
> let's just not do passthrough operations like this for reconfig. There
> is no need to bring in the kernel.
>
> For the initial config we can still do it since we have to maintain
> compat, but for major reconfigs like this let's just have targetcli
> contact tcmu-runner, then runner can update the kernel if needed.
>
> So in targetcli and runner copy the check_config stuff, and add a
> reconfig callout that works like it. We then do not have this weird
> kernel passthrough and do not have to worry about the non
> targetcl-tcmu-runner type of model.
>
>
>
So you basically want me to use DBUS correct? Connect a GCallback function

with reconfig function and use DBUS to pass info back to kernel if necessary?

-Bryant

Re: [PATCH] tcmu: Allow reconfig to handle multiple attributes

[Mike Christie]

On 01/04/2018 10:11 AM, Bryant G. Ly wrote:
> This patch allows for multiple attributes to be reconfigured
> and handled all in one call as compared to multiple netlinks.
> 
> Example:
> set attribute dev_reconfig=dev_config=fbo//home/path:dev_size=2147483648
> 

I know I suggested this, but I think I was wrong. If we have to support
other apps that work in reverse to targetcli+tcmu-runner where the
tcmu-runner equivalent app sets things up then contacts the kernel,
let's just not do passthrough operations like this for reconfig. There
is no need to bring in the kernel.

For the initial config we can still do it since we have to maintain
compat, but for major reconfigs like this let's just have targetcli
contact tcmu-runner, then runner can update the kernel if needed.

So in targetcli and runner copy the check_config stuff, and add a
reconfig callout that works like it. We then do not have this weird
kernel passthrough and do not have to worry about the non
targetcl-tcmu-runner type of model.



> Signed-off-by: Bryant G. Ly 
> ---
>  drivers/target/target_core_user.c | 92 
> ++-
>  include/uapi/linux/target_core_user.h |  1 +
>  2 files changed, 92 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/target/target_core_user.c 
> b/drivers/target/target_core_user.c
> index 4824abf92ed79..619fae5e865f1 100644
> --- a/drivers/target/target_core_user.c
> +++ b/drivers/target/target_core_user.c
> @@ -152,6 +152,8 @@ struct tcmu_dev {
>   char dev_config[TCMU_CONFIG_LEN];
>  
>   int nl_reply_supported;
> +
> + char dev_reconfig[TCMU_CONFIG_LEN * 2];
>  };
>  
>  #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
> @@ -1452,6 +1454,10 @@ static int tcmu_netlink_event(struct tcmu_dev *udev, 
> enum tcmu_genl_cmd cmd,
>   ret = nla_put_u8(skb, reconfig_attr,
> *((u8 *)reconfig_data));
>   break;
> + case TCMU_ATTR_DEV_RECFG:
> + pr_err("Put string into netlink and send it\n");
> + ret = nla_put_string(skb, reconfig_attr, reconfig_data);
> + break;
>   default:
>   BUG();
>   }
> @@ -1637,7 +1643,7 @@ static void tcmu_destroy_device(struct se_device *dev)
>  
>  enum {
>   Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
> - Opt_nl_reply_supported, Opt_err,
> + Opt_nl_reply_supported, Opt_dev_reconfig, Opt_err,
>  };
>  
>  static match_table_t tokens = {
> @@ -1646,6 +1652,7 @@ static match_table_t tokens = {
>   {Opt_hw_block_size, "hw_block_size=%u"},
>   {Opt_hw_max_sectors, "hw_max_sectors=%u"},
>   {Opt_nl_reply_supported, "nl_reply_supported=%d"},
> + {Opt_dev_reconfig, "dev_reconfig=%s"},
>   {Opt_err, NULL}
>  };
>  
> @@ -1731,6 +1738,14 @@ static ssize_t tcmu_set_configfs_dev_params(struct 
> se_device *dev,
>   if (ret < 0)
>   pr_err("kstrtoint() failed for 
> nl_reply_supported=\n");
>   break;
> + case Opt_dev_reconfig:
> + arg_p = match_strdup([0]);
> + if (!arg_p) {
> + ret = -ENOMEM;
> + break;
> + }
> + kfree(arg_p);
> + break;
>   default:
>   break;
>   }
> @@ -1945,12 +1960,87 @@ static ssize_t tcmu_emulate_write_cache_store(struct 
> config_item *item,
>  }
>  CONFIGFS_ATTR(tcmu_, emulate_write_cache);
>  
> +static ssize_t tcmu_dev_reconfig_show(struct config_item *item, char *page)
> +{
> + struct se_dev_attrib *da = container_of(to_config_group(item),
> + struct se_dev_attrib, da_group);
> + struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
> +
> + return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_reconfig);
> +}
> +
> +static ssize_t tcmu_dev_reconfig_store(struct config_item *item,
> +const char *page,
> +size_t count)
> +{
> + struct se_dev_attrib *da = container_of(to_config_group(item),
> + struct se_dev_attrib, da_group);
> + struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
> + int token, ret;
> + char *orig, *ptr, *opts, *arg_p;
> + substring_t args[MAX_OPT_ARGS];
> +
> + /* Check if device has been configured before */
> + if (tcmu_dev_configured(udev)) {
> + ret = tcmu_netlink_event(udev, TCMU_CMD_RECONFIG_DEVICE,
> +  TCMU_ATTR_DEV_RECFG, page);
> + if (ret) {
> + pr_err("Unable to reconfigure device\n");
> + return ret;
> + }
> +
> + opts = 

[PATCH] tcmu: Allow reconfig to handle multiple attributes

[Bryant G. Ly]

This patch allows for multiple attributes to be reconfigured
and handled all in one call as compared to multiple netlinks.

Example:
set attribute dev_reconfig=dev_config=fbo//home/path:dev_size=2147483648

Signed-off-by: Bryant G. Ly 
---
 drivers/target/target_core_user.c | 92 ++-
 include/uapi/linux/target_core_user.h |  1 +
 2 files changed, 92 insertions(+), 1 deletion(-)

diff --git a/drivers/target/target_core_user.c 
b/drivers/target/target_core_user.c
index 4824abf92ed79..619fae5e865f1 100644
--- a/drivers/target/target_core_user.c
+++ b/drivers/target/target_core_user.c
@@ -152,6 +152,8 @@ struct tcmu_dev {
char dev_config[TCMU_CONFIG_LEN];
 
int nl_reply_supported;
+
+   char dev_reconfig[TCMU_CONFIG_LEN * 2];
 };
 
 #define TCMU_DEV(_se_dev) container_of(_se_dev, struct tcmu_dev, se_dev)
@@ -1452,6 +1454,10 @@ static int tcmu_netlink_event(struct tcmu_dev *udev, 
enum tcmu_genl_cmd cmd,
ret = nla_put_u8(skb, reconfig_attr,
  *((u8 *)reconfig_data));
break;
+   case TCMU_ATTR_DEV_RECFG:
+   pr_err("Put string into netlink and send it\n");
+   ret = nla_put_string(skb, reconfig_attr, reconfig_data);
+   break;
default:
BUG();
}
@@ -1637,7 +1643,7 @@ static void tcmu_destroy_device(struct se_device *dev)
 
 enum {
Opt_dev_config, Opt_dev_size, Opt_hw_block_size, Opt_hw_max_sectors,
-   Opt_nl_reply_supported, Opt_err,
+   Opt_nl_reply_supported, Opt_dev_reconfig, Opt_err,
 };
 
 static match_table_t tokens = {
@@ -1646,6 +1652,7 @@ static match_table_t tokens = {
{Opt_hw_block_size, "hw_block_size=%u"},
{Opt_hw_max_sectors, "hw_max_sectors=%u"},
{Opt_nl_reply_supported, "nl_reply_supported=%d"},
+   {Opt_dev_reconfig, "dev_reconfig=%s"},
{Opt_err, NULL}
 };
 
@@ -1731,6 +1738,14 @@ static ssize_t tcmu_set_configfs_dev_params(struct 
se_device *dev,
if (ret < 0)
pr_err("kstrtoint() failed for 
nl_reply_supported=\n");
break;
+   case Opt_dev_reconfig:
+   arg_p = match_strdup([0]);
+   if (!arg_p) {
+   ret = -ENOMEM;
+   break;
+   }
+   kfree(arg_p);
+   break;
default:
break;
}
@@ -1945,12 +1960,87 @@ static ssize_t tcmu_emulate_write_cache_store(struct 
config_item *item,
 }
 CONFIGFS_ATTR(tcmu_, emulate_write_cache);
 
+static ssize_t tcmu_dev_reconfig_show(struct config_item *item, char *page)
+{
+   struct se_dev_attrib *da = container_of(to_config_group(item),
+   struct se_dev_attrib, da_group);
+   struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
+
+   return snprintf(page, PAGE_SIZE, "%s\n", udev->dev_reconfig);
+}
+
+static ssize_t tcmu_dev_reconfig_store(struct config_item *item,
+  const char *page,
+  size_t count)
+{
+   struct se_dev_attrib *da = container_of(to_config_group(item),
+   struct se_dev_attrib, da_group);
+   struct tcmu_dev *udev = TCMU_DEV(da->da_dev);
+   int token, ret;
+   char *orig, *ptr, *opts, *arg_p;
+   substring_t args[MAX_OPT_ARGS];
+
+   /* Check if device has been configured before */
+   if (tcmu_dev_configured(udev)) {
+   ret = tcmu_netlink_event(udev, TCMU_CMD_RECONFIG_DEVICE,
+TCMU_ATTR_DEV_RECFG, page);
+   if (ret) {
+   pr_err("Unable to reconfigure device\n");
+   return ret;
+   }
+
+   opts = kstrdup(page, GFP_KERNEL);
+   if (!opts)
+   return -ENOMEM;
+
+   orig = opts;
+   strcpy(udev->dev_reconfig, opts);
+
+   while ((ptr = strsep(, ":")) != NULL) {
+   if (!*ptr)
+   continue;
+
+   token = match_token(ptr, tokens, args);
+   switch (token) {
+   case Opt_dev_config:
+   if (match_strlcpy(udev->dev_config, [0],
+ TCMU_CONFIG_LEN) == 0) {
+   pr_err("Could not reconfigure 
dev_config");
+   }
+   ret = tcmu_update_uio_info(udev);
+   if (ret)
+   pr_err("Could not