Re: [PATCH v5 03/18] btrfs: expose quota mode via sysfs
From: David Sterba <hidden>
Date: 2023-09-07 17:30:50
On Thu, Jul 27, 2023 at 03:12:50PM -0700, Boris Burkov wrote:
Add a new sysfs file /sys/fs/btrfs/<uuid>/qgroups/mode which prints out the mode qgroups is running in. The possible modes are disabled, qgroup, and squota
Can you get the 'disabled' at all? Because when the quotas are disabled by ioctl the whole sysfs directory is gone, see btrfs_free_qgroup_config().
quoted hunk ↗ jump to hunk
Signed-off-by: Boris Burkov <redacted> --- fs/btrfs/sysfs.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index b1d1ac25237b..e53614753391 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c@@ -2086,6 +2086,31 @@ static ssize_t qgroup_enabled_show(struct kobject *qgroups_kobj, } BTRFS_ATTR(qgroups, enabled, qgroup_enabled_show); +static ssize_t qgroup_mode_show(struct kobject *qgroups_kobj, + struct kobj_attribute *a, + char *buf) +{ + struct btrfs_fs_info *fs_info = to_fs_info(qgroups_kobj->parent); + char *mode = ""; + + spin_lock(&fs_info->qgroup_lock); + switch (btrfs_qgroup_mode(fs_info)) { + case BTRFS_QGROUP_MODE_DISABLED: + mode = "disabled"; + break; + case BTRFS_QGROUP_MODE_FULL: + mode = "qgroup"; + break; + case BTRFS_QGROUP_MODE_SIMPLE: + mode = "squota";
You can do
lock;
switch (mode) {
case FULL: sysfs_emit(buf, "qgroup\n"); break;
case SIMPLE: sysfs_emit(buf, "simple\n"); break;
}
unlock;
return 7;
or track the return value from sysfs_emit so it's not so hacky.
quoted hunk ↗ jump to hunk
+ break; + } + spin_unlock(&fs_info->qgroup_lock); + + return sysfs_emit(buf, "%s\n", mode); +} +BTRFS_ATTR(qgroups, mode, qgroup_mode_show); + static ssize_t qgroup_inconsistent_show(struct kobject *qgroups_kobj, struct kobj_attribute *a, char *buf)@@ -2148,6 +2173,7 @@ static struct attribute *qgroups_attrs[] = { BTRFS_ATTR_PTR(qgroups, enabled), BTRFS_ATTR_PTR(qgroups, inconsistent), BTRFS_ATTR_PTR(qgroups, drop_subtree_threshold), + BTRFS_ATTR_PTR(qgroups, mode), NULL }; ATTRIBUTE_GROUPS(qgroups);-- 2.41.0