[PATCH] driver core: update comments in device_rename()

From: Wedson Almeida Filho
Date: Thu Apr 06 2023 - 00:54:58 EST


From: Wedson Almeida Filho <walmeida@xxxxxxxxxxxxx>

Document that some subsystems are still going to use device_rename for
the time being, so it is not a good idea to assume it's not used. Also
remove mentions of a plan to stop renaming net devices.

Signed-off-by: Wedson Almeida Filho <walmeida@xxxxxxxxxxxxx>
---
drivers/base/core.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 6878dfcbf0d6..95d414074f92 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4383,9 +4383,12 @@ EXPORT_SYMBOL_GPL(device_destroy);
* on the same device to ensure that new_name is valid and
* won't conflict with other devices.
*
- * Note: Don't call this function. Currently, the networking layer calls this
- * function, but that will change. The following text from Kay Sievers offers
- * some insight:
+ * Note: given that some subsystems (networking and infiniband) use this
+ * function, with no immediate plans for this to change, we cannot assume or
+ * require that this function not be called at all.
+ *
+ * However, if you're writing new code, do not call this function. The following
+ * text from Kay Sievers offers some insight:
*
* Renaming devices is racy at many levels, symlinks and other stuff are not
* replaced atomically, and you get a "move" uevent, but it's not easy to
@@ -4399,13 +4402,6 @@ EXPORT_SYMBOL_GPL(device_destroy);
* kernel device renaming. Besides that, it's not even implemented now for
* other things than (driver-core wise very simple) network devices.
*
- * We are currently about to change network renaming in udev to completely
- * disallow renaming of devices in the same namespace as the kernel uses,
- * because we can't solve the problems properly, that arise with swapping names
- * of multiple interfaces without races. Means, renaming of eth[0-9]* will only
- * be allowed to some other name than eth[0-9]*, for the aforementioned
- * reasons.
- *
* Make up a "real" name in the driver before you register anything, or add
* some other attributes for userspace to find the device, or use udev to add
* symlinks -- but never rename kernel devices later, it's a complete mess. We
--
2.34.1