| Message ID | 20231012111401.333798-4-leitao@debian.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 5fbd6cdbe304b4154f63e3f8abf7c9c644ccb62c |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: netconsole: configfs entries for boot target | expand |
On Thu, Oct 12, 2023 at 04:14:00AM -0700, Breno Leitao wrote: > Enable the attachment of a dynamic target to the target created during > boot time. The boot-time targets are named as "cmdline\d", where "\d" is > a number starting at 0. > > If the user creates a dynamic target named "cmdline0", it will attach to > the first target created at boot time (as defined in the > `netconsole=...` command line argument). `cmdline1` will attach to the > second target and so forth. > > If there is no netconsole target created at boot time, then, the target > name could be reused. > > Relevant design discussion: > https://lore.kernel.org/all/ZRWRal5bW93px4km@gmail.com/ > > Suggested-by: Joel Becker <jlbec@evilplan.org> > Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Joel Becker <jlbec@evilplan.org> > --- > drivers/net/netconsole.c | 28 ++++++++++++++++++++++++++++ > 1 file changed, 28 insertions(+) > > diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c > index e153bce4dee4..6e14ba5e06c8 100644 > --- a/drivers/net/netconsole.c > +++ b/drivers/net/netconsole.c > @@ -629,6 +629,23 @@ static const struct config_item_type netconsole_target_type = { > .ct_owner = THIS_MODULE, > }; > > +static struct netconsole_target *find_cmdline_target(const char *name) > +{ > + struct netconsole_target *nt, *ret = NULL; > + unsigned long flags; > + > + spin_lock_irqsave(&target_list_lock, flags); > + list_for_each_entry(nt, &target_list, list) { > + if (!strcmp(nt->item.ci_name, name)) { > + ret = nt; > + break; > + } > + } > + spin_unlock_irqrestore(&target_list_lock, flags); > + > + return ret; > +} > + > /* > * Group operations and type for netconsole_subsys. > */ > @@ -639,6 +656,17 @@ static struct config_item *make_netconsole_target(struct config_group *group, > struct netconsole_target *nt; > unsigned long flags; > > + /* Checking if a target by this name was created at boot time. If so, > + * attach a configfs entry to that target. This enables dynamic > + * control. > + */ > + if (!strncmp(name, NETCONSOLE_PARAM_TARGET_PREFIX, > + strlen(NETCONSOLE_PARAM_TARGET_PREFIX))) { > + nt = find_cmdline_target(name); > + if (nt) > + return &nt->item; > + } > + > nt = alloc_and_init(); > if (!nt) > return ERR_PTR(-ENOMEM); > -- > 2.34.1 >
diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index e153bce4dee4..6e14ba5e06c8 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -629,6 +629,23 @@ static const struct config_item_type netconsole_target_type = { .ct_owner = THIS_MODULE, }; +static struct netconsole_target *find_cmdline_target(const char *name) +{ + struct netconsole_target *nt, *ret = NULL; + unsigned long flags; + + spin_lock_irqsave(&target_list_lock, flags); + list_for_each_entry(nt, &target_list, list) { + if (!strcmp(nt->item.ci_name, name)) { + ret = nt; + break; + } + } + spin_unlock_irqrestore(&target_list_lock, flags); + + return ret; +} + /* * Group operations and type for netconsole_subsys. */ @@ -639,6 +656,17 @@ static struct config_item *make_netconsole_target(struct config_group *group, struct netconsole_target *nt; unsigned long flags; + /* Checking if a target by this name was created at boot time. If so, + * attach a configfs entry to that target. This enables dynamic + * control. + */ + if (!strncmp(name, NETCONSOLE_PARAM_TARGET_PREFIX, + strlen(NETCONSOLE_PARAM_TARGET_PREFIX))) { + nt = find_cmdline_target(name); + if (nt) + return &nt->item; + } + nt = alloc_and_init(); if (!nt) return ERR_PTR(-ENOMEM);
Enable the attachment of a dynamic target to the target created during boot time. The boot-time targets are named as "cmdline\d", where "\d" is a number starting at 0. If the user creates a dynamic target named "cmdline0", it will attach to the first target created at boot time (as defined in the `netconsole=...` command line argument). `cmdline1` will attach to the second target and so forth. If there is no netconsole target created at boot time, then, the target name could be reused. Relevant design discussion: https://lore.kernel.org/all/ZRWRal5bW93px4km@gmail.com/ Suggested-by: Joel Becker <jlbec@evilplan.org> Signed-off-by: Breno Leitao <leitao@debian.org> --- drivers/net/netconsole.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)