| Message ID | 20190830113611.16865-5-jthumshirn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: support xxhash64 checksums | expand |
On Fri, Aug 30, 2019 at 01:36:11PM +0200, Johannes Thumshirn wrote: > From: David Sterba <dsterba@suse.com> I did not write the patch. > Export supported checksum algorithms via sysfs. > > Signed-off-by: David Sterba <dsterba@suse.com> > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> And 'git am' complains that there are two s-o-b lines. > Reviewed-by: Nikolay Borisov <nborisov@suse.com> > > --- > Changes to v2: > - Prevent possible overflow of sysfs attribute > Changes to v1: > - Removed btrfs_checksums_store() function (Nik) > - Renamed sysfs file to supported_checksums > --- > fs/btrfs/sysfs.c | 29 +++++++++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c > index f6d3c80f2e28..cae9c99253c7 100644 > --- a/fs/btrfs/sysfs.c > +++ b/fs/btrfs/sysfs.c > @@ -246,6 +246,24 @@ static umode_t btrfs_feature_visible(struct kobject *kobj, > return mode; > } > > +static ssize_t btrfs_supported_checksums_show(struct kobject *kobj, > + struct kobj_attribute *a, > + char *buf) > +{ > + ssize_t ret = 0; > + int i; > + > + for (i = 0; i < ARRAY_SIZE(btrfs_csums); i++) { We'll need one more helper to return the number of csums, btrfs_csums is not visible in sysfs.c anymore (aka it does not compile). > + ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s", > + (i == 0 ? "" : ", "), I've checked some sysfs files what's commonly used for a value separator and there are more examples of ' ', though ', ' is also there. I'd prefer to use a single letter separator. > + btrfs_csums[i].name); > + > + } > + > + ret += snprintf(buf + ret, PAGE_SIZE - ret, "\n"); > + return ret; > +} > + > BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); > BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); > BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); > @@ -259,6 +277,14 @@ BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES); > BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID); > BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE); > > +static struct btrfs_feature_attr btrfs_attr_features_checksums_name = { > + .kobj_attr = __INIT_KOBJ_ATTR(supported_checksums, S_IRUGO, > + btrfs_supported_checksums_show, > + NULL), > + .feature_set = FEAT_INCOMPAT, > + .feature_bit = 0, > +}; > + > static struct attribute *btrfs_supported_feature_attrs[] = { > BTRFS_FEAT_ATTR_PTR(mixed_backref), > BTRFS_FEAT_ATTR_PTR(default_subvol), > @@ -272,6 +298,9 @@ static struct attribute *btrfs_supported_feature_attrs[] = { > BTRFS_FEAT_ATTR_PTR(no_holes), > BTRFS_FEAT_ATTR_PTR(metadata_uuid), > BTRFS_FEAT_ATTR_PTR(free_space_tree), > + > + &btrfs_attr_features_checksums_name.kobj_attr.attr, This belongs to the static features, ie. the same scheme as rmdir_subvol. The two lists are merged together in sysfs directory, but should be defined separately as they represent different type of features. > + > NULL > }; > > -- > 2.16.4
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index f6d3c80f2e28..cae9c99253c7 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -246,6 +246,24 @@ static umode_t btrfs_feature_visible(struct kobject *kobj, return mode; } +static ssize_t btrfs_supported_checksums_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + ssize_t ret = 0; + int i; + + for (i = 0; i < ARRAY_SIZE(btrfs_csums); i++) { + ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s", + (i == 0 ? "" : ", "), + btrfs_csums[i].name); + + } + + ret += snprintf(buf + ret, PAGE_SIZE - ret, "\n"); + return ret; +} + BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); @@ -259,6 +277,14 @@ BTRFS_FEAT_ATTR_INCOMPAT(no_holes, NO_HOLES); BTRFS_FEAT_ATTR_INCOMPAT(metadata_uuid, METADATA_UUID); BTRFS_FEAT_ATTR_COMPAT_RO(free_space_tree, FREE_SPACE_TREE); +static struct btrfs_feature_attr btrfs_attr_features_checksums_name = { + .kobj_attr = __INIT_KOBJ_ATTR(supported_checksums, S_IRUGO, + btrfs_supported_checksums_show, + NULL), + .feature_set = FEAT_INCOMPAT, + .feature_bit = 0, +}; + static struct attribute *btrfs_supported_feature_attrs[] = { BTRFS_FEAT_ATTR_PTR(mixed_backref), BTRFS_FEAT_ATTR_PTR(default_subvol), @@ -272,6 +298,9 @@ static struct attribute *btrfs_supported_feature_attrs[] = { BTRFS_FEAT_ATTR_PTR(no_holes), BTRFS_FEAT_ATTR_PTR(metadata_uuid), BTRFS_FEAT_ATTR_PTR(free_space_tree), + + &btrfs_attr_features_checksums_name.kobj_attr.attr, + NULL };