[systemd-devel] [PATCH] rules: Fix by-path of mmc RPMB partitions and don't blkid them

[Martin Pitt]

Linux 3.10+ exposes RPMB (Replay Protected Memory Block) partitions of MMC
devices [1] ; trying to read them with blkid or other unspecific means will
cause kernel buffer I/O errors and timeouts. So don't run blkid on these.

Also ensure that /dev/disk/by-path creates proper symlinks and exposes the
-rpmb partition separately, instead of letting the "normal" partition symlink
point to the rpbm device (this is a race condition).

[1] http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=090d25fe224c0

https://launchpad.net/bugs/1333140
---
 rules/60-persistent-storage.rules | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/rules/60-persistent-storage.rules b/rules/60-persistent-storage.rules
index 475b151..19fc4dc 100644
--- a/rules/60-persistent-storage.rules
+++ b/rules/60-persistent-storage.rules
@@ -53,7 +53,8 @@ KERNEL=="mspblk[0-9]p[0-9]", ENV{ID_NAME}=="?*", ENV{ID_SERIAL}=="?*", SYMLINK+=
 
 # by-path (parent device path)
 ENV{DEVTYPE}=="disk", DEVPATH!="*/virtual/*", IMPORT{builtin}="path_id"
-ENV{DEVTYPE}=="disk", ENV{ID_PATH}=="?*", SYMLINK+="disk/by-path/$env{ID_PATH}"
+ENV{DEVTYPE}=="disk", ENV{ID_PATH}=="?*", KERNEL=="mmcblk[0-9]rpmb", SYMLINK+="disk/by-path/$env{ID_PATH}-rpmb"
+ENV{DEVTYPE}=="disk", ENV{ID_PATH}=="?*", KERNEL!="mmcblk[0-9]rpmb", SYMLINK+="disk/by-path/$env{ID_PATH}"
 ENV{DEVTYPE}=="partition", ENV{ID_PATH}=="?*", SYMLINK+="disk/by-path/$env{ID_PATH}-part%n"
 
 # skip unpartitioned removable media devices from drivers which do not send "change" events
@@ -66,6 +67,9 @@ KERNEL=="sr*", ENV{DISK_EJECT_REQUEST}!="?*", ENV{ID_CDROM_MEDIA_TRACK_COUNT_DAT
 KERNEL=="sr*", ENV{DISK_EJECT_REQUEST}!="?*", ENV{ID_CDROM_MEDIA_TRACK_COUNT_DATA}=="?*", ENV{ID_CDROM_MEDIA_SESSION_LAST_OFFSET}=="", \
   IMPORT{builtin}="blkid --noraid"
 
+# don't try to read Replay Protected Memory Block partitions
+KERNEL=="mmcblk[0-9]rpmb", GOTO="persistent_storage_end"
+
 # probe filesystem metadata of disks
 KERNEL!="sr*", IMPORT{builtin}="blkid"
 
-- 
2.1.4