diff mbox series

[net-next,4/6] devlink: Require devlink lock during device reload

Message ID d9bc1d4d54a647020fe853abe5f93bcfd30b6bc1.1638690564.git.leonro@nvidia.com (mailing list archive)
State Rejected
Delegated to: Netdev Maintainers
Headers show
Series Allow parallel devlink execution | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 6 this patch: 6
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 20 this patch: 20
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 22 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Leon Romanovsky Dec. 5, 2021, 8:22 a.m. UTC 
From: Leon Romanovsky <leonro@nvidia.com>

Devlink reload was implemented as a special command which does _SET_
operation, but doesn't take devlink->lock, while recursive devlink
calls that were part of .reload_up()/.reload_down() sequence took it.

This fragile flow was possible due to holding a big devlink lock
(devlink_mutex), which effectively stopped all devlink activities,
even unrelated to reloaded devlink.

So let's make sure that devlink reload behaves as other commands.

Tested-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
---
 net/core/devlink.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 7dd6091b97af..cbffafc1776f 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -8810,7 +8810,6 @@  static const struct genl_small_ops devlink_nl_ops[] = {
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
 		.doit = devlink_nl_cmd_reload,
 		.flags = GENL_ADMIN_PERM,
-		.internal_flags = DEVLINK_NL_FLAG_NO_LOCK,
 	},
 	{
 		.cmd = DEVLINK_CMD_PARAM_GET,
@@ -11448,10 +11447,15 @@  static void __net_exit devlink_pernet_pre_exit(struct net *net)
 			goto retry;
 
 		WARN_ON(!(devlink->features & DEVLINK_F_RELOAD));
+
+		mutex_lock(&devlink->lock);
+		xa_set_mark(&devlinks, devlink->index, DEVLINK_NESTED_LOCK);
 		err = devlink_reload(devlink, &init_net,
 				     DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
 				     DEVLINK_RELOAD_LIMIT_UNSPEC,
 				     &actions_performed, NULL);
+		xa_clear_mark(&devlinks, devlink->index, DEVLINK_NESTED_LOCK);
+		mutex_unlock(&devlink->lock);
 		if (err && err != -EOPNOTSUPP)
 			pr_warn("Failed to reload devlink instance into init_net\n");
 retry: