diff options
| author | Anand Jain <anand.jain@oracle.com> | 2023-06-20 16:55:09 +0800 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2023-08-21 14:52:12 +0200 |
| commit | 070bb0011ccfd00c7de25dce2489fbe9cce5ba44 (patch) | |
| tree | 7fef65256cb8b193035c6076680655263b2c31a3 /fs/btrfs/sysfs.c | |
| parent | 3a3c7a7f6506338bcc4ebe6c5a2cbfec016ce50c (diff) | |
btrfs: sysfs: show if ACL support has been compiled in
ACL support depends on the compile-time configuration option
CONFIG_BTRFS_FS_POSIX_ACL. Prior to mounting a btrfs filesystem, it is not
possible to determine whether ACL support has been compiled in. To address
this, add a sysfs interface, /sys/fs/btrfs/features/acl, and check for ACL
support in the system's btrfs.
To determine ACL support:
Return 0 indicates ACL is not supported:
$ cat /sys/fs/btrfs/features/acl
0
Return 1 indicates ACL is supported:
$ cat /sys/fs/btrfs/features/acl
1
IMO, this is a better approach, so that we also know if kernel is older.
On an older kernel
$ ls /sys/fs/btrfs/features/acl
ls: cannot access '/sys/fs/btrfs/features/acl': No such file or directory
mount a btrfs filesystem
$ cat /proc/self/mounts | grep btrfs | grep -q noacl
$ echo $?
0
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/sysfs.c')
| -rw-r--r-- | fs/btrfs/sysfs.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 25294e624851..b1d1ac25237b 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -414,6 +414,12 @@ static ssize_t supported_sectorsizes_show(struct kobject *kobj, BTRFS_ATTR(static_feature, supported_sectorsizes, supported_sectorsizes_show); +static ssize_t acl_show(struct kobject *kobj, struct kobj_attribute *a, char *buf) +{ + return sysfs_emit(buf, "%d\n", !!IS_ENABLED(CONFIG_BTRFS_FS_POSIX_ACL)); +} +BTRFS_ATTR(static_feature, acl, acl_show); + /* * Features which only depend on kernel version. * @@ -421,6 +427,7 @@ BTRFS_ATTR(static_feature, supported_sectorsizes, * btrfs_supported_feature_attrs. */ static struct attribute *btrfs_supported_static_feature_attrs[] = { + BTRFS_ATTR_PTR(static_feature, acl), BTRFS_ATTR_PTR(static_feature, rmdir_subvol), BTRFS_ATTR_PTR(static_feature, supported_checksums), BTRFS_ATTR_PTR(static_feature, send_stream_version), |