On 3/20/24 22:31, Filipe Manana wrote:
On Wed, Mar 20, 2024 at 11:34 AM Anand Jain <anand.jain@xxxxxxxxxx> wrote:
On 3/19/24 23:42, David Sterba wrote:
From: Josef Bacik <josef@xxxxxxxxxxxxxx>
Btrfs has had the ability for almost a decade to allow ro and rw
mounting of subvols. This behavior specifically
mount -o subvol=foo,ro /some/dir
mount -o subvol=bar,rw /some/other/dir
This seems simple, but because of the limitations of how we did mounting
in ye olde days we would mark the super block as RO and the mount if we
mounted RO first. In the case above /some/dir would instantiate the
super block as read only and the mount point. So the second mount
command under the covers would convert the super block to RW, and then
allow the mount to continue.
The results were still consistent, /some/dir was still read only because
the mount was marked read only, but /some/other/dir could be written to.
This is a test to make sure we maintain this behavior, as I almost
regressed this behavior while converting us to the new mount API.
Signed-off-by: Josef Bacik <josef@xxxxxxxxxxxxxx>
looks good.
Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx>
Nits below.
---
tests/btrfs/330 | 54 +++++++++++++++++++++++++++++++++++++++++++++
tests/btrfs/330.out | 6 +++++
2 files changed, 60 insertions(+)
create mode 100755 tests/btrfs/330
create mode 100644 tests/btrfs/330.out
diff --git a/tests/btrfs/330 b/tests/btrfs/330
new file mode 100755
index 00000000000000..3ce9840e76d028
--- /dev/null
+++ b/tests/btrfs/330
@@ -0,0 +1,54 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2023 Meta Platforms, Inc. All Rights Reserved.
+#
+# FS QA Test No. btrfs/330
+#
+# Test mounting one subvolume as ro and another as rw
+#
+. ./common/preamble
+_begin_fstest auto quick subvol
+
+_cleanup()
+{
+ rm -rf $TEST_DIR/$seq
+}
+
+# Import common functions.
+. ./common/filter
This can be deleted, as the filter.btrfs also calls the filter.
+. ./common/filter.btrfs
+
+# real QA test starts here
+_supported_fs btrfs
+_require_scratch
+
+$MOUNT_PROG -V | grep -q 'fd-based-mount'
+[ "$?" -eq 0 ] && _notrun "mount uses the new mount api"
+
+_scratch_mkfs > /dev/null 2>&1
_scratch_mkfs >> $seqres.full
Errors, if any, go to stdout.
We typically redirect stderr to stdout because in the past mkfs.btrfs
used to output to stderr a message when it performed trim.
See this old commit:
https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/commit/?id=afadb6e5958c5acf2425d6a8a9372b63afcb4f2a
And nowadays we're encouraged to do:
_scratch_mkfs >> $seqres.full 2>&1 || _fail "mkfs failed"
So in case mkfs fails the test doesn't continue and silently passes by
using the filesystem SCRATCH_MNT belongs to.
Darn it, I keep forgetting about the trimmed message history that went
to stderr. My bad. And I did search mkfs for what went to stderr, but it
wasn't an error. Btrfs/303 fixed.
Thanks, Anand
