| Message ID | 20191007091104.18095-4-jthumshirn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add xxhash64 and sha256 as possible new checksums | expand |
On 7.10.19 г. 12:11 ч., Johannes Thumshirn wrote: > From: David Sterba <dsterba@suse.com> > > Export supported checksum algorithms via sysfs. > > Co-developed-by: David Sterba <dsterba@suse.com> > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> > --- > fs/btrfs/ctree.c | 5 +++++ > fs/btrfs/ctree.h | 2 ++ > fs/btrfs/sysfs.c | 33 +++++++++++++++++++++++++++++++++ > 3 files changed, 40 insertions(+) > > diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c > index b66509ee62eb..5debd74dc61c 100644 > --- a/fs/btrfs/ctree.c > +++ b/fs/btrfs/ctree.c > @@ -53,6 +53,11 @@ const char *btrfs_super_csum_name(u16 csum_type) > return btrfs_csums[csum_type].name; > } > > +size_t btrfs_get_num_csums(void) > +{ > + return ARRAY_SIZE(btrfs_csums); > +} nit: This function is used only once and the ARRAY_SIZE() macro is descriptive enough, why not just remove it and opencoude the call to array_size > + > struct btrfs_path *btrfs_alloc_path(void) > { > return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); > diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h > index d17e79a40930..0180554f6970 100644 > --- a/fs/btrfs/ctree.h > +++ b/fs/btrfs/ctree.h > @@ -2165,6 +2165,8 @@ BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block, > > int btrfs_super_csum_size(const struct btrfs_super_block *s); > const char *btrfs_super_csum_name(u16 csum_type); > +size_t btrfs_get_num_csums(void); > + > > /* > * The leaf data grows from end-to-front in the node. > diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c > index f6d3c80f2e28..aeebbdfe1a98 100644 > --- a/fs/btrfs/sysfs.c > +++ b/fs/btrfs/sysfs.c > @@ -246,6 +246,28 @@ 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 < btrfs_get_num_csums(); i++) { > + /* > + * This "trick" only works as long as 'enum btrfs_csum_type' has > + * no holes in it > + */ > + ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s", > + (i == 0 ? "" : ", "), > + btrfs_super_csum_name(i)); > + > + } > + > + 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 +281,14 @@ 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 +302,9 @@ 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 > }; > >
On Mon, Oct 07, 2019 at 06:36:14PM +0300, Nikolay Borisov wrote: > > > On 7.10.19 г. 12:11 ч., Johannes Thumshirn wrote: > > From: David Sterba <dsterba@suse.com> > > > > Export supported checksum algorithms via sysfs. > > > > Co-developed-by: David Sterba <dsterba@suse.com> > > Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> > > --- > > fs/btrfs/ctree.c | 5 +++++ > > fs/btrfs/ctree.h | 2 ++ > > fs/btrfs/sysfs.c | 33 +++++++++++++++++++++++++++++++++ > > 3 files changed, 40 insertions(+) > > > > diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c > > index b66509ee62eb..5debd74dc61c 100644 > > --- a/fs/btrfs/ctree.c > > +++ b/fs/btrfs/ctree.c > > @@ -53,6 +53,11 @@ const char *btrfs_super_csum_name(u16 csum_type) > > return btrfs_csums[csum_type].name; > > } > > > > +size_t btrfs_get_num_csums(void) > > +{ > > + return ARRAY_SIZE(btrfs_csums); > > +} > > nit: This function is used only once and the ARRAY_SIZE() macro is > descriptive enough, why not just remove it and opencoude the call to > array_size Agreed, ARRAY_SIZE in loops is fine, it's a compile-time constant.
On 07/10/2019 17:46, David Sterba wrote: [...] >> nit: This function is used only once and the ARRAY_SIZE() macro is >> descriptive enough, why not just remove it and opencoude the call to >> array_size > > Agreed, ARRAY_SIZE in loops is fine, it's a compile-time constant. Nope, btrfs_csums[] is defined in ctree.c, so I can't get the size of this array outside of ctree.c. And it was moved to ctree.c from ctree.h on request by David.
On Tue, Oct 08, 2019 at 08:47:14AM +0200, Johannes Thumshirn wrote: > On 07/10/2019 17:46, David Sterba wrote: > [...] > >> nit: This function is used only once and the ARRAY_SIZE() macro is > >> descriptive enough, why not just remove it and opencoude the call to > >> array_size > > > > Agreed, ARRAY_SIZE in loops is fine, it's a compile-time constant. > > Nope, btrfs_csums[] is defined in ctree.c, so I can't get the size of > this array outside of ctree.c. And it was moved to ctree.c from ctree.h > on request by David. Ohh, right you are of course.
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index b66509ee62eb..5debd74dc61c 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -53,6 +53,11 @@ const char *btrfs_super_csum_name(u16 csum_type) return btrfs_csums[csum_type].name; } +size_t btrfs_get_num_csums(void) +{ + return ARRAY_SIZE(btrfs_csums); +} + struct btrfs_path *btrfs_alloc_path(void) { return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index d17e79a40930..0180554f6970 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2165,6 +2165,8 @@ BTRFS_SETGET_STACK_FUNCS(super_uuid_tree_generation, struct btrfs_super_block, int btrfs_super_csum_size(const struct btrfs_super_block *s); const char *btrfs_super_csum_name(u16 csum_type); +size_t btrfs_get_num_csums(void); + /* * The leaf data grows from end-to-front in the node. diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index f6d3c80f2e28..aeebbdfe1a98 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -246,6 +246,28 @@ 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 < btrfs_get_num_csums(); i++) { + /* + * This "trick" only works as long as 'enum btrfs_csum_type' has + * no holes in it + */ + ret += snprintf(buf + ret, PAGE_SIZE - ret, "%s%s", + (i == 0 ? "" : ", "), + btrfs_super_csum_name(i)); + + } + + 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 +281,14 @@ 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 +302,9 @@ 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 };