From: Johannes Thumshirn <jthumshirn@suse.de>
To: David Sterba <dsterba@suse.com>
Cc: Linux BTRFS Mailinglist <linux-btrfs@vger.kernel.org>,
Nikolay Borisov <nborisov@suse.com>,
Johannes Thumshirn <jthumshirn@suse.de>
Subject: [PATCH 3/4] btrfs: sysfs: export supported checksums
Date: Mon, 7 Oct 2019 11:11:03 +0200 [thread overview]
Message-ID: <20191007091104.18095-4-jthumshirn@suse.de> (raw)
In-Reply-To: <20191007091104.18095-1-jthumshirn@suse.de>
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);
+}
+
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
};
--
2.16.4
next prev parent reply other threads:[~2019-10-07 9:11 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-07 9:11 [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums Johannes Thumshirn
2019-10-07 9:11 ` [PATCH 1/4] btrfs: add xxhash64 to checksumming algorithms Johannes Thumshirn
2019-10-07 9:11 ` [PATCH 2/4] btrfs: add sha256 " Johannes Thumshirn
2019-10-07 9:11 ` Johannes Thumshirn [this message]
2019-10-07 15:36 ` [PATCH 3/4] btrfs: sysfs: export supported checksums Nikolay Borisov
2019-10-07 15:46 ` David Sterba
2019-10-08 6:47 ` Johannes Thumshirn
2019-10-08 11:40 ` David Sterba
2019-10-07 9:11 ` [PATCH 4/4] btrfs: show used checksum driver per filesystem in sysfs Johannes Thumshirn
2019-10-07 14:58 ` [PATCH 0/4] Add xxhash64 and sha256 as possible new checksums Nikolay Borisov
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