[net-next,v3,2/4] netconsole: Initialize configfs_item for default targets

Message ID 20231010093751.3878229-3-leitao@debian.org
State New
Headers
Series [net-next,v3,1/4] netconsole: move init/cleanup functions lower |

Commit Message

Breno Leitao Oct. 10, 2023, 9:37 a.m. UTC
  For netconsole targets allocated during the boot time (passing
netconsole=... argument), netconsole_target->item is not initialized.
That is not a problem because it is not used inside configfs.

An upcoming patch will be using it, thus, initialize the targets with
the name 'cmdline' plus a counter starting from 0.  This name will match
entries in the configfs later.

Suggested-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
---
 drivers/net/netconsole.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)
  

Comments

Joel Becker Oct. 10, 2023, 7:27 p.m. UTC | #1
On Tue, Oct 10, 2023 at 02:37:49AM -0700, Breno Leitao wrote:
> For netconsole targets allocated during the boot time (passing
> netconsole=... argument), netconsole_target->item is not initialized.
> That is not a problem because it is not used inside configfs.
> 
> An upcoming patch will be using it, thus, initialize the targets with
> the name 'cmdline' plus a counter starting from 0.  This name will match
> entries in the configfs later.
> 
> Suggested-by: Joel Becker <jlbec@evilplan.org>
> Signed-off-by: Breno Leitao <leitao@debian.org>
> ---
>  drivers/net/netconsole.c | 25 +++++++++++++++++++++++--
>  1 file changed, 23 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> index d609fb59cf99..3d7002af505d 100644
> --- a/drivers/net/netconsole.c
> +++ b/drivers/net/netconsole.c
> @@ -53,6 +53,8 @@ static bool oops_only = false;
>  module_param(oops_only, bool, 0600);
>  MODULE_PARM_DESC(oops_only, "Only log oops messages");
>  
> +#define NETCONSOLE_PARAM_TARGET_NAME "cmdline"

Perhaps `NETCONSOLE_PARAM_TARGET_PREFIX` is better.  Makes it clear this
is not the whole name.

Thanks,
Joel
  
Jakub Kicinski Oct. 11, 2023, 1:10 a.m. UTC | #2
On Tue, 10 Oct 2023 12:27:34 -0700 Joel Becker wrote:
> > +#define NETCONSOLE_PARAM_TARGET_NAME "cmdline"  
> 
> Perhaps `NETCONSOLE_PARAM_TARGET_PREFIX` is better.  Makes it clear this
> is not the whole name.

FWIW I had the same thought when looking at v2.
Didn't wanna nit-pick but if there's two of us...
  
Breno Leitao Oct. 11, 2023, 12:38 p.m. UTC | #3
On Tue, Oct 10, 2023 at 12:27:34PM -0700, Joel Becker wrote:
> On Tue, Oct 10, 2023 at 02:37:49AM -0700, Breno Leitao wrote:
> > For netconsole targets allocated during the boot time (passing
> > netconsole=... argument), netconsole_target->item is not initialized.
> > That is not a problem because it is not used inside configfs.
> > 
> > An upcoming patch will be using it, thus, initialize the targets with
> > the name 'cmdline' plus a counter starting from 0.  This name will match
> > entries in the configfs later.
> > 
> > Suggested-by: Joel Becker <jlbec@evilplan.org>
> > Signed-off-by: Breno Leitao <leitao@debian.org>
> > ---
> >  drivers/net/netconsole.c | 25 +++++++++++++++++++++++--
> >  1 file changed, 23 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
> > index d609fb59cf99..3d7002af505d 100644
> > --- a/drivers/net/netconsole.c
> > +++ b/drivers/net/netconsole.c
> > @@ -53,6 +53,8 @@ static bool oops_only = false;
> >  module_param(oops_only, bool, 0600);
> >  MODULE_PARM_DESC(oops_only, "Only log oops messages");
> >  
> > +#define NETCONSOLE_PARAM_TARGET_NAME "cmdline"
> 
> Perhaps `NETCONSOLE_PARAM_TARGET_PREFIX` is better.  Makes it clear this
> is not the whole name.

Sure, I can replace it by NETCONSOLE_PARAM_TARGET_PREFIX. I used
`NETCONSOLE_PARAM_TARGET_NAME` because you had suggested it in the past:

https://lore.kernel.org/all/ZR3EKnepIOKlVGgZ@google.com/

Let me update and send a new version.
  

Patch

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index d609fb59cf99..3d7002af505d 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -53,6 +53,8 @@  static bool oops_only = false;
 module_param(oops_only, bool, 0600);
 MODULE_PARM_DESC(oops_only, "Only log oops messages");
 
+#define NETCONSOLE_PARAM_TARGET_NAME "cmdline"
+
 #ifndef	MODULE
 static int __init option_setup(char *opt)
 {
@@ -165,6 +167,10 @@  static void netconsole_target_put(struct netconsole_target *nt)
 {
 }
 
+static void populate_configfs_item(struct netconsole_target *nt,
+				   int cmdline_count)
+{
+}
 #endif	/* CONFIG_NETCONSOLE_DYNAMIC */
 
 /* Allocate and initialize with defaults.
@@ -688,6 +694,17 @@  static struct configfs_subsystem netconsole_subsys = {
 	},
 };
 
+static void populate_configfs_item(struct netconsole_target *nt,
+				   int cmdline_count)
+{
+	char target_name[16];
+
+	snprintf(target_name, sizeof(target_name), "%s%d",
+		 NETCONSOLE_PARAM_TARGET_NAME, cmdline_count);
+	config_item_init_type_name(&nt->item, target_name,
+				   &netconsole_target_type);
+}
+
 #endif	/* CONFIG_NETCONSOLE_DYNAMIC */
 
 /* Handle network interface device notifications */
@@ -887,7 +904,8 @@  static void write_msg(struct console *con, const char *msg, unsigned int len)
 }
 
 /* Allocate new target (from boot/module param) and setup netpoll for it */
-static struct netconsole_target *alloc_param_target(char *target_config)
+static struct netconsole_target *alloc_param_target(char *target_config,
+						    int cmdline_count)
 {
 	struct netconsole_target *nt;
 	int err;
@@ -922,6 +940,7 @@  static struct netconsole_target *alloc_param_target(char *target_config)
 	if (err)
 		goto fail;
 
+	populate_configfs_item(nt, cmdline_count);
 	nt->enabled = true;
 
 	return nt;
@@ -954,6 +973,7 @@  static int __init init_netconsole(void)
 {
 	int err;
 	struct netconsole_target *nt, *tmp;
+	unsigned int count = 0;
 	bool extended = false;
 	unsigned long flags;
 	char *target_config;
@@ -961,7 +981,7 @@  static int __init init_netconsole(void)
 
 	if (strnlen(input, MAX_PARAM_LENGTH)) {
 		while ((target_config = strsep(&input, ";"))) {
-			nt = alloc_param_target(target_config);
+			nt = alloc_param_target(target_config, count);
 			if (IS_ERR(nt)) {
 				err = PTR_ERR(nt);
 				goto fail;
@@ -977,6 +997,7 @@  static int __init init_netconsole(void)
 			spin_lock_irqsave(&target_list_lock, flags);
 			list_add(&nt->list, &target_list);
 			spin_unlock_irqrestore(&target_list_lock, flags);
+			count++;
 		}
 	}