From 079b72bca30dbc74c86c7c7825b8c34eb86ce3ee Mon Sep 17 00:00:00 2001 From: Jeff Mahoney Date: Fri, 1 Nov 2013 13:06:57 -0400 Subject: btrfs: publish supported featured in sysfs This patch adds the ability to publish supported features to sysfs under /sys/fs/btrfs/features. The files are module-wide and export which features the kernel supports. The content, for now, is just "0\n". Signed-off-by: Jeff Mahoney Signed-off-by: Josef Bacik Signed-off-by: Chris Mason --- fs/btrfs/sysfs.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'fs/btrfs/sysfs.c') diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 5b326cd60a4a..9e217b581903 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -26,20 +26,64 @@ #include "ctree.h" #include "disk-io.h" #include "transaction.h" +#include "sysfs.h" + +static ssize_t btrfs_feature_attr_show(struct kobject *kobj, + struct kobj_attribute *a, char *buf) +{ + return snprintf(buf, PAGE_SIZE, "0\n"); +} + +BTRFS_FEAT_ATTR_INCOMPAT(mixed_backref, MIXED_BACKREF); +BTRFS_FEAT_ATTR_INCOMPAT(default_subvol, DEFAULT_SUBVOL); +BTRFS_FEAT_ATTR_INCOMPAT(mixed_groups, MIXED_GROUPS); +BTRFS_FEAT_ATTR_INCOMPAT(compress_lzo, COMPRESS_LZO); +BTRFS_FEAT_ATTR_INCOMPAT(compress_lzov2, COMPRESS_LZOv2); +BTRFS_FEAT_ATTR_INCOMPAT(big_metadata, BIG_METADATA); +BTRFS_FEAT_ATTR_INCOMPAT(extended_iref, EXTENDED_IREF); +BTRFS_FEAT_ATTR_INCOMPAT(raid56, RAID56); +BTRFS_FEAT_ATTR_INCOMPAT(skinny_metadata, SKINNY_METADATA); + +static struct attribute *btrfs_supported_feature_attrs[] = { + BTRFS_FEAT_ATTR_PTR(mixed_backref), + BTRFS_FEAT_ATTR_PTR(default_subvol), + BTRFS_FEAT_ATTR_PTR(mixed_groups), + BTRFS_FEAT_ATTR_PTR(compress_lzo), + BTRFS_FEAT_ATTR_PTR(compress_lzov2), + BTRFS_FEAT_ATTR_PTR(big_metadata), + BTRFS_FEAT_ATTR_PTR(extended_iref), + BTRFS_FEAT_ATTR_PTR(raid56), + BTRFS_FEAT_ATTR_PTR(skinny_metadata), + NULL +}; + +static const struct attribute_group btrfs_feature_attr_group = { + .name = "features", + .attrs = btrfs_supported_feature_attrs, +}; /* /sys/fs/btrfs/ entry */ static struct kset *btrfs_kset; int btrfs_init_sysfs(void) { + int ret; btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj); if (!btrfs_kset) return -ENOMEM; + + ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); + if (ret) { + kset_unregister(btrfs_kset); + return ret; + } + return 0; } void btrfs_exit_sysfs(void) { + sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); kset_unregister(btrfs_kset); } -- cgit v1.2.3