Hi, thanks for the reply, please see my comments embedded below.
On Wed, Jan 08, 2020 at 06:29:30PM -0800, Jaegeuk Kim wrote: > Hi, > > On 01/08, Piergiorgio Sartor wrote: > > Hi all, > > > > I've a small box, with Fedora 31 up-to-date. > > > > The system has LUKS + LVM + f2fs. > > > > Since kernel 5.3.16-300.fc31.x86_64 the fstrim.service, > > triggered by the systemd service fstrim.timer or from > > command line, does return an error: > > > > Starting Discard unused blocks on filesystems from /etc/fstab... > > fstrim: /home: FITRIM ioctl failed: Read-only file system > > fstrim: /: FITRIM ioctl failed: Read-only file system > > fstrim.service: Main process exited, code=exited, status=32/n/a > > fstrim.service: Failed with result 'exit-code'. > > Failed to start Discard unused blocks on filesystems from /etc/fstab. > > It smells like trying fstrim along with /etc/fstab before mounting the > partitions? The error is reported also when running, as root, the command "systemctl start fstrim.service" from command line, that is with partitions available. So, I do not think it is before mounting. Also, this is usually started weekly from fstrim.timer, and this requires a running system. It could be a strange conflict with systemd, but with ext4 there is no problem, it happens with f2fs. > > Note the following: > > 1) Both /home and / are rw > > 2) LUKS and LVM allow discard to the underlying device > > 3) An other PC, with same layout, but ext4, does work as expected > > 4) kernel 5.4.7-200.fc31.x86_64 (latest for f31) has same result > > 5) fstrim -vA or -va does not return an error, exit code is 0, > > but it always says 0 (zero) bytes are trimmed: > > > > /home: 0 B (0 bytes) trimmed on /dev/mapper/fedora--server-home > > /: 0 B (0 bytes) trimmed on /dev/mapper/fedora--server-root > > This is normal. Since f2fs issues discard commands asynchronously, fstrim > just collects discard candidates and returns right away. Later, it will > actually issue the candidates in background. Whereas, if it was mounted as > "-o nodiscard", fstrim will wait for whole discard commands being issued > and completed as you expect. OK, I remounted / with "nodiscard", created a 1GB file, synched the fs, deleted the file and issued "fstrim -vA". I can confirm 1GB was trimmed, more precisely 1.1GB according to "fstrim". I repeated the test, but instead using "systemctl start fstrim.service". Same error as before. But, a succesive "fstrim -vA" returned only 2.7MB trimmed. This could be that the "fstrim" call was executed properly, but some error report was triggered. Maybe the read-only file system is not correct, but something happened. I would like to stress again that ext4 does not trigger this error. So, there is something related with f2fs, at least with the interaction with fstrim and systemd. I have one question. Since f2fs is mounted with "discard" and, as I understand it, f2fs will issue discard as soon as a segment is freed, is it relevant to have the weekly fstrim from systemd? Thanks a lot in advance, bye, pg > > Thanks, > > > > > 6) mount shows that the f2fs mounts have "discard" flag > > > > So, I suspect there is something with f2fs which somehow > > confuses the trimming process. > > > > I had a quick search, but I could not find any other > > similar report, except one about systemd, but that > > does not seem related. > > > > Any idea? Suggestions? > > Debugging possibilities? > > > > Thanks a lot in advance, > > > > bye, > > > > -- > > > > piergiorgio > > > > > > _______________________________________________ > > Linux-f2fs-devel mailing list > > Linux-f2fs-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel -- piergiorgio _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
