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authorDavid Sterba <dsterba@suse.com>2019-10-07 11:11:03 +0200
committerDavid Sterba <dsterba@suse.com>2019-11-18 17:51:43 +0100
commitf7cea56c0fff95bd5a6cd21b9fa299f66193b604 (patch)
treee59752010527d9314d500aec9542f17c98279092 /fs/btrfs/sysfs.c
parent3831bf0094abed51e71cbeca8b6edf8b88c2644b (diff)
downloadlinux-f7cea56c0fff95bd5a6cd21b9fa299f66193b604.tar.bz2
btrfs: sysfs: export supported checksums
Export supported checksum algorithms via sysfs in the list of static features: /sys/fs/btrfs/features/supported_checksums Space spearated list of checksum algorithm names. Co-developed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/sysfs.c')
-rw-r--r--fs/btrfs/sysfs.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c
index f6d3c80f2e28..41eb6a313bf8 100644
--- a/fs/btrfs/sysfs.c
+++ b/fs/btrfs/sysfs.c
@@ -295,8 +295,30 @@ static ssize_t rmdir_subvol_show(struct kobject *kobj,
}
BTRFS_ATTR(static_feature, rmdir_subvol, rmdir_subvol_show);
+static ssize_t 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_ATTR(static_feature, supported_checksums, supported_checksums_show);
+
static struct attribute *btrfs_supported_static_feature_attrs[] = {
BTRFS_ATTR_PTR(static_feature, rmdir_subvol),
+ BTRFS_ATTR_PTR(static_feature, supported_checksums),
NULL
};