From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Wed, 6 Apr 2022 11:18:51 +0000 (+0900)
Subject: udev: add a brief comment about the origin of the filters
X-Git-Tag: v251-rc2~183
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a9e832092a36b1ecd6cc4e10abd2160cf0210954;p=thirdparty%2Fsystemd.git

udev: add a brief comment about the origin of the filters

I am not sure whether the original discussions are correct or not.
This is just for adding references for future verification for the
filters.
---

diff --git a/src/udev/udevd.c b/src/udev/udevd.c
index 4a37a769247..078cd960b42 100644
--- a/src/udev/udevd.c
+++ b/src/udev/udevd.c
@@ -442,6 +442,12 @@ static int device_get_whole_disk(sd_device *dev, sd_device **ret_device, const c
         if (r < 0)
                 return log_device_debug_errno(dev, r, "Failed to get sysname: %m");
 
+        /* Exclude the following devices:
+         * For "dm-", see the comment added by e918a1b5a94f270186dca59156354acd2a596494.
+         * For "md", see the commit message of 2e5b17d01347d3c3118be2b8ad63d20415dbb1f0,
+         * but not sure the assumption is still valid even when partitions are created on the md
+         * devices, surprisingly which seems to be possible, see PR #22973.
+         * For "drbd", see the commit message of fee854ee8ccde0cd28e0f925dea18cce35f3993d. */
         if (STARTSWITH_SET(val, "dm-", "md", "drbd"))
                 goto irrelevant;