SUMMARY Unmounting an SD card results in it being re-mounted again if "automount on attach is enabled". STEPS TO REPRODUCE 1. Enable "Automount all known devices on attach" on the desktop settings. 2. Insert an SD card in the reader (can be reproduced on a VM). The volume should be mounted automatically. 3. Click on "Safely remove" to unmount the volume. OBSERVED RESULT The volume is re-mounted again immediately. EXPECTED RESULT The volume remains unmounted. SOFTWARE/OS VERSIONS KDE Plasma Version: 5.27.2 KDE Frameworks Version: 5.103.0 Qt Version: 5.15.8 ADDITIONAL INFORMATION Hi, I'm unsure about whether this is an actual bug in KDE, UDisks, or not a bug at all, so let me explain the situation. SD card readers have the "MediaRemovable" flag set in UDisks: https://github.com/storaged-project/udisks/blob/2.9.x-branch/src/udiskslinuxdrive.c#L368 This, according to the UDisks documentation, seems to only mean that "the media can be removed from the drive". However, Solid uses that information to decide whether to _eject_ the volume when the user tries to "Safely remove" the volume from the desktop. The "Ejectable" flag from UDisks was previously used for this purpose but it was discarded because it was considered broken (bug #402096, commit https://github.com/KDE/solid/commit/6d260195cf75604d835235d2a1b02166ee8b514a). The UDisks Eject command runs /usr/bin/eject under the hood, but this won't actually eject the card from the reader, so it fails (I'm using a VM in this example but the same happens with real hardware): $ busctl call org.freedesktop.UDisks2 /org/freedesktop/UDisks2/drives/QEMU__0xdeadbeef org.freedesktop.UDisks2.Drive Eject 'a{sv}' 0 Call failed: Error ejecting /dev/mmcblk0: Command-line `eject '/dev/mmcblk0'' exited with non-zero exit status 1: eject: unable to eject This results in the following udev events: UDEV [9144.057110] remove /devices/pci0000:00/0000:00:04.0/mmc_host/mmc0/mmc0:4567/block/mmcblk0/mmcblk0p1 (block) UDEV [9144.105960] change /devices/pci0000:00/0000:00:04.0/mmc_host/mmc0/mmc0:4567/block/mmcblk0 (block) UDEV [9144.193215] add /devices/pci0000:00/0000:00:04.0/mmc_host/mmc0/mmc0:4567/block/mmcblk0/mmcblk0p1 (block) Because of these remove+add events, if "Automount all known devices on attach" is set under the removable devices settings and you try to safely remove an SD card then the volume is immediately re-mounted again. I also noticed that this does not happen in GNOME and this is due to a workaround there: if a volume appears much later than the drive (as in this case) then it is not mounted automatically: https://gitlab.gnome.org/GNOME/gvfs/-/commit/b4800b987b4a8423a52306c9aef35b3777464cc5 So while doing something like this would be a possibility, is it maybe possible to find a way to know whether the media in a certain drive is actually ejectable, and not simply removable? Otherwise it seems that Solid should not try to use eject based only on the "MediaRemovable" flag. Opinions?
*** Bug 446395 has been marked as a duplicate of this bug. ***
Can't reproduce with my card and card reader, FWIW. So I think it depends on the hardware's adherence to the spec, which underscores the flakiness here. Perhaps Solid can grow the ability to check for whether an unmounted volume immediately gets an "add" event from udisks, and ignore it if it's under a certain timeout. Say, 100ms.
In case you want to give it a try with QEMU, here's a very simple test case: 1) Boot a VM with a virtual SD card reader, like this: -device sdhci-pci -device sd-card,drive=mmc0 -drive if=none,file=card.qcow2,id=mmc0 2) Add a partition to the SD card, no need to format it (you can use GPT or DOS/MBR, it doesn't matter). 3) Run `udevadm monitor` and in a different terminal run `eject /dev/mmcblk0` This is enough to see the udev events I mentioned earlier. The check that you describe seems fine (assuming that timeout is not too small). Thanks!
A possibly relevant merge request was started @ https://invent.kde.org/frameworks/solid/-/merge_requests/128
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-desktop/-/merge_requests/1454
"eject" in this context forces the card reader/drive to flush any pending operations from its caches. The timestamp based heuristic does not work in all cases, as a card reader will have a constant "TimeDetected" timestamp, and plugging a card into it will result in a significantly later "TimeMediaDetected". @ Alberto: Can you please provide the output of "udisctl monitor", when you run "/usr/bin/eject /dev/mmcblk0; echo $? "?.
(You likely have to run "eject" as root, e.g. via sudo. In case eject returns with a non-zero exit code, stracing it may reveal further information - "sudo strace -s 200 eject /dev/mmcblk0".)
Created attachment 157742 [details] strace output The strace output is attached. Here's the output of the eject and monitor commands: # /usr/bin/eject /dev/mmcblk0; echo $? eject: unable to eject 1 # udisksctl monitor Monitoring the udisks daemon. Press Ctrl+C to exit. 15:43:49.633: The udisks-daemon is running (name-owner :1.29). 15:43:50.504: Removed /org/freedesktop/UDisks2/block_devices/mmcblk0p1 15:43:50.538: /org/freedesktop/UDisks2/block_devices/mmcblk0: org.freedesktop.UDisks2.PartitionTable: Properties Changed Partitions: 15:43:50.629: Added /org/freedesktop/UDisks2/block_devices/mmcblk0p1 org.freedesktop.UDisks2.Block: Configuration: [] CryptoBackingDevice: '/' Device: /dev/mmcblk0p1 DeviceNumber: 45825 Drive: '/org/freedesktop/UDisks2/drives/SL16G_0x8c9ed258' HintAuto: true HintIconName: HintIgnore: false HintName: HintPartitionable: true HintSymbolicIconName: HintSystem: false Id: by-uuid-9019398f-1e38-4f69-bca4-6feb56d98ed7 IdLabel: SD_CARD IdType: ext4 IdUUID: 9019398f-1e38-4f69-bca4-6feb56d98ed7 IdUsage: filesystem IdVersion: 1.0 MDRaid: '/' MDRaidMember: '/' PreferredDevice: /dev/mmcblk0p1 ReadOnly: false Size: 15929966592 Symlinks: /dev/disk/by-id/mmc-SL16G_0x8c9ed258-part1 /dev/disk/by-label/SD_CARD /dev/disk/by-partlabel/primary /dev/disk/by-partuuid/679ecb89-c2df-4e55-ac6a-e8be61e2709d /dev/disk/by-uuid/9019398f-1e38-4f69-bca4-6feb56d98ed7 UserspaceMountOptions: org.freedesktop.UDisks2.Filesystem: MountPoints: Size: 15929966592 org.freedesktop.UDisks2.Partition: Flags: 0 IsContained: false IsContainer: false Name: primary Number: 1 Offset: 1048576 Size: 15929966592 Table: '/org/freedesktop/UDisks2/block_devices/mmcblk0' Type: 0fc63daf-8483-4772-8e79-3d69d8477de4 UUID: 679ecb89-c2df-4e55-ac6a-e8be61e2709d 15:43:50.629: /org/freedesktop/UDisks2/block_devices/mmcblk0: org.freedesktop.UDisks2.PartitionTable: Properties Changed Partitions: /org/freedesktop/UDisks2/block_devices/mmcblk0p1
According to the strace output, the drive supports none of the four attempted methods of eject, i.e. the ioctl's 'CDROM_LOCKDOOR', 'SG_IO(...)', 'FDEJECT' and 'MTIOCTOP'. I can confirm the behavior by issuing e.g. 'eject -f ...', as FDEJECT is not supported by my card reader (it supports the SCSI ioctl) I also get the UDEV REMOVED/CHANGED/ADDED sequence.
(In reply to Stefan Brüns from comment #9) > According to the strace output, the drive supports none of the four > attempted methods of eject, i.e. the ioctl's 'CDROM_LOCKDOOR', 'SG_IO(...)', > 'FDEJECT' and 'MTIOCTOP'. FWIW the same happens with QEMU's virtual SD card reader (the strace output I attached earlier is from actual hardware).
There's one more thing to take into account with the "5 seconds since plugged" heuristic: the case when the volume was present at coldplug (i.e. it was already there when the session started). Related links for the GNOME implementation: https://gitlab.gnome.org/GNOME/gvfs/-/commit/e30a67f3215d829e95ee7e358c67af7d67635fe8 https://bugzilla.redhat.com/show_bug.cgi?id=813069
Git commit 41eaa14d3375e303e68e0d2f39090f5ed4f48c82 by David Edmundson. Committed on 21/06/2023 at 10:45. Pushed by davidedmundson into branch 'master'. Expose StorageDevice timeDetected/timeMediaDetected For automounting purposes it's useful to know when a drive appeared in relation to when StorageVolumes appear. Rather than adding tracking in front-end code we can make use of udisk's existing information. M +10 -0 src/solid/devices/backends/fakehw/fakestorage.cpp M +3 -0 src/solid/devices/backends/fakehw/fakestorage.h M +20 -0 src/solid/devices/backends/udisks2/udisksstoragedrive.cpp M +3 -0 src/solid/devices/backends/udisks2/udisksstoragedrive.h M +12 -0 src/solid/devices/frontend/storagedrive.cpp M +21 -0 src/solid/devices/frontend/storagedrive.h M +10 -0 src/solid/devices/ifaces/storagedrive.cpp M +12 -0 src/solid/devices/ifaces/storagedrive.h https://invent.kde.org/frameworks/solid/-/commit/41eaa14d3375e303e68e0d2f39090f5ed4f48c82