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| author | Darsey Litzenberger <dlitz@dlitz.net> | 2022-07-11 06:47:45 +0200 |
|---|---|---|
| committer | Yu Watanabe <watanabe.yu+github@gmail.com> | 2022-07-15 00:54:14 +0200 |
| commit | b5e17d7fed3ab1f1f2c64a20d904390577b53fa9 (patch) | |
| tree | 780be2370f614f3aae85c27d3d69e3eda911ef6f /rules.d | |
| parent | update TODO (diff) | |
| download | systemd-b5e17d7fed3ab1f1f2c64a20d904390577b53fa9.tar.xz systemd-b5e17d7fed3ab1f1f2c64a20d904390577b53fa9.zip | |
udev: add flag to allow disabling blkid probing
This can be useful for users of slow block devices.
For example, the persistent-storage rules are needed for USB floppy
drives be recognized by udisks2, but the extra blkid calls cause
thrashing for 25+ seconds after every disk change.
With this change, a user wishing to avoid the extra blkid invocation(s)
could create /etc/udev/rules.d/55-floppy-noprobe.rules as follows:
# Don't probe PC floppy drives
SUBSYSTEM=="block", KERNEL=="fd*", \
ENV{UDEV_DISABLE_PERSISTENT_STORAGE_BLKID_FLAG}="1"
# Don't probe USB floppy drives
SUBSYSTEM=="block", SUBSYSTEMS=="usb", \
ATTRS{bInterfaceClass}=="08", ATTRS{bInterfaceSubClass}=="04", \
ENV{UDEV_DISABLE_PERSISTENT_STORAGE_BLKID_FLAG}="1"
I didn't exclude floppies by default in this change, because floppy
devices are also emulated by some BIOSes/hypervisors in some cases, and
I don't know how many systems would fail to boot if /dev/disk/by-uuid/*
became unavailable for 'floppy disks' on those systems.
Diffstat (limited to 'rules.d')
| -rw-r--r-- | rules.d/60-persistent-storage.rules | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/rules.d/60-persistent-storage.rules b/rules.d/60-persistent-storage.rules index de08428207..03f0a619dc 100644 --- a/rules.d/60-persistent-storage.rules +++ b/rules.d/60-persistent-storage.rules @@ -99,6 +99,9 @@ ENV{DEVTYPE}=="partition", ENV{ID_PATH_ATA_COMPAT}=="?*", SYMLINK+="disk/by-path KERNEL=="vd*[!0-9]", ENV{ID_PATH}=="pci-*", SYMLINK+="disk/by-path/virtio-$env{ID_PATH}" KERNEL=="vd*[0-9]", ENV{ID_PATH}=="pci-*", SYMLINK+="disk/by-path/virtio-$env{ID_PATH}-part%n" +# allow admin to disable probing the filesystem for slow devices like floppy disk drives +ENV{UDEV_DISABLE_PERSISTENT_STORAGE_BLKID_FLAG}=="1", GOTO="persistent_storage_blkid_probe_end" + # probe filesystem metadata of optical drives which have a media inserted KERNEL=="sr*", ENV{DISK_EJECT_REQUEST}!="?*", ENV{ID_CDROM_MEDIA_TRACK_COUNT_DATA}=="?*", ENV{ID_CDROM_MEDIA_SESSION_LAST_OFFSET}=="?*", \ IMPORT{builtin}="blkid --hint=session_offset=$env{ID_CDROM_MEDIA_SESSION_LAST_OFFSET}" @@ -109,6 +112,8 @@ KERNEL=="sr*", ENV{DISK_EJECT_REQUEST}!="?*", ENV{ID_CDROM_MEDIA_TRACK_COUNT_DAT # probe filesystem metadata of disks KERNEL!="sr*|mmcblk[0-9]boot[0-9]", IMPORT{builtin}="blkid" +LABEL="persistent_storage_blkid_probe_end" + # by-label/by-uuid links (filesystem metadata) ENV{ID_FS_USAGE}=="filesystem|other|crypto", ENV{ID_FS_UUID_ENC}=="?*", SYMLINK+="disk/by-uuid/$env{ID_FS_UUID_ENC}" ENV{ID_FS_USAGE}=="filesystem|other|crypto", ENV{ID_FS_LABEL_ENC}=="?*", SYMLINK+="disk/by-label/$env{ID_FS_LABEL_ENC}" |