On Thu, Apr 30, 2020 at 01:37:39PM +0000, Johannes Thumshirn wrote:
> On 04/04/2020 12:32, Goffredo Baroncelli wrote:
> >
> > Hi all,
> >
> > the aim of this patch set is to issue a warning when a mixed profiles
> > filesystem is detected. This happens when the filesystems contains
> > (i.e.) raid1c3 and single chunk for data.
> >
> > BTRFS has the capability to support a filesystem with mixed profiles.
> > However this could lead to an unexpected behavior when a new chunk is
> > allocated (i.e. the chunk profile is not what is wanted). Moreover
> > if the user is not aware of this, he could assume a redundancy which
> > doesn't exist (for example because there is some 'single' chunk when
> > it is expected the filesystem to be full raid1).
> > A possible cause of a mixed profiles filesystem is an interrupted
> > balance operation or a not fully balance due to very specific filter.
> >
> > The check is added to the following btrfs commands:
> > - btrfs balance pause
> > - btrfs balance cancel
> > - btrfs device add
> > - btrfs device del
> >
> > The warning is shorter than the before one. Below an example and
> > it is printed after the normal output of the command.
> >
> > WARNING: Multiple profiles detected. See 'man btrfs(5)'.
> > WARNING: data -> [raid1c3, single], metadata -> [raid1, single]
> >
> > The command "btrfs fi us" doesn't show the warning above, instead
> > it was added a further line in the "Overall" section. The output now
> > is this:
> >
> > $ sudo ./btrfs fi us /tmp/t/
> > [sudo] password for ghigo:
> > Overall:
> > Device size: 30.00GiB
> > Device allocated: 4.78GiB
> > Device unallocated: 25.22GiB
> > Device missing: 0.00B
> > Used: 1.95GiB
> > Free (estimated): 13.87GiB (min: 9.67GiB)
> > Data ratio: 2.00
> > Metadata ratio: 1.50
> > Global reserve: 3.25MiB (used: 0.00B)
> > Multiple profile: YES
> >
> > Data,single: Size:1.00GiB, Used:974.04MiB (95.12%)
> > /dev/loop0 1.00GiB
> >
> > Data,RAID1C3: Size:1.00GiB, Used:178.59MiB (17.44%)
> > /dev/loop0 1.00GiB
> > /dev/loop1 1.00GiB
> > /dev/loop2 1.00GiB
> >
> > Metadata,single: Size:256.00MiB, Used:76.22MiB (29.77%)
> > /dev/loop1 256.00MiB
> >
> > Metadata,RAID1: Size:256.00MiB, Used:206.92MiB (80.83%)
> > /dev/loop1 256.00MiB
> > /dev/loop2 256.00MiB
> >
> > System,single: Size:32.00MiB, Used:16.00KiB (0.05%)
> > /dev/loop2 32.00MiB
> >
> > Unallocated:
> > /dev/loop0 8.00GiB
> > /dev/loop1 8.50GiB
> > /dev/loop2 8.72GiB
> >
> >
> > In this case there are two kind of chunks for data (raid1c3 and single)
> > and metadata (raid1, single).
> >
> > As the previous patch set, the warning is added also to the command
> > 'btrfs fi df' and 'btrfs dev us' as separate patch. If even in this
> > review nobody likes it, we can simply drop this patch.
> >
> > Suggestion about which commands should (not) have this check are
> > welcome.
> >
> > v1
> > - first issue
> > v2
> > - add some needed missing pieces about raid1c[34]
> > - add the check to more btrfs commands
> > v3
> > - add a section in btrfs(5) 'FILESYSTEM WITH MULTIPLE PROFILES'
> > - 'btrfs fi us': changed the worning in a info in the 'overall' section
> >
> > Patch #1 contains the code for the check.
> > Patch #3 adds the check to the command 'btrfs dev {add,del}' and 'btrfs
> > bal {pause, stop}'
> > Patch #3 adds the check to the command 'btrfs fi us'
> > Patch #5 add the check to the command 'btrfs fi df' and 'btrfs dev us'
> > Patch #5 add the info in btrfs(5) man page
>
> Btw with this patchset applied fstests choke on some tests (e.g.
> btrfs/003) in my setup:
>
> btrfs/003 - output mismatch (see
> /home/johannes/src/xfstests-dev/results//btrfs/003.out.bad)
> --- tests/btrfs/003.out 2020-01-02 08:43:50.000000000 +0000
> +++ /home/johannes/src/xfstests-dev/results//btrfs/003.out.bad
> 2020-04-30 13:20:43.050569551 +0000
> @@ -1,2 +1,4 @@
> QA output created by 003
> +WARNING: Multiple profiles detected. See 'man btrfs(5)'.
> +WARNING:
Well, the tests need to be adjusted to filter that message out.
