From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cantor2.suse.de ([195.135.220.15]:47366 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752850Ab3IJEat (ORCPT ); Tue, 10 Sep 2013 00:30:49 -0400 Message-Id: <20130910043007.783624453@suse.com> Date: Tue, 10 Sep 2013 00:24:11 -0400 From: Jeff Mahoney To: linux-btrfs@vger.kernel.org Cc: clmason@fusionio.com, dsterba@suse.cz Subject: [patch 3/7] btrfs: Add per-super attributes to sysfs References: <20130910042408.335071038@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: This patch adds per-super attributes to sysfs. It doesn't publish any attributes yet, but does the proper lifetime handling as well as the basic infrastructure to add new attributes. Signed-off-by: Jeff Mahoney --- fs/btrfs/ctree.h | 2 + fs/btrfs/super.c | 13 +++++++++++- fs/btrfs/sysfs.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/btrfs/sysfs.h | 19 ++++++++++++++++++ 4 files changed, 91 insertions(+), 1 deletion(-) --- a/fs/btrfs/ctree.h 2013-09-10 00:09:12.990087784 -0400 +++ b/fs/btrfs/ctree.h 2013-09-10 00:09:35.521794520 -0400 @@ -3694,6 +3694,8 @@ int btrfs_defrag_leaves(struct btrfs_tra /* sysfs.c */ int btrfs_init_sysfs(void); void btrfs_exit_sysfs(void); +int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info); +void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info); /* xattr.c */ ssize_t btrfs_listxattr(struct dentry *dentry, char *buffer, size_t size); --- a/fs/btrfs/super.c 2013-09-10 00:09:12.994087730 -0400 +++ b/fs/btrfs/super.c 2013-09-10 00:09:35.525794464 -0400 @@ -301,6 +301,8 @@ void __btrfs_panic(struct btrfs_fs_info static void btrfs_put_super(struct super_block *sb) { + btrfs_sysfs_remove_one(btrfs_sb(sb)); + (void)close_ctree(btrfs_sb(sb)->tree_root); /* FIXME: need to fix VFS to return error? */ /* AV: return it _where_? ->put_super() can be triggered by any number @@ -1143,8 +1145,17 @@ static struct dentry *btrfs_mount(struct } root = !error ? get_default_root(s, subvol_objectid) : ERR_PTR(error); - if (IS_ERR(root)) + if (IS_ERR(root)) { deactivate_locked_super(s); + return root; + } + + error = btrfs_sysfs_add_one(fs_info); + if (error) { + dput(root); + deactivate_locked_super(s); + return ERR_PTR(error); + } return root; --- a/fs/btrfs/sysfs.c 2013-09-10 00:09:13.002087628 -0400 +++ b/fs/btrfs/sysfs.c 2013-09-10 00:09:49.501616538 -0400 @@ -61,6 +61,64 @@ static struct attribute *btrfs_supp_feat NULL }; +static struct attribute *btrfs_attrs[] = { + NULL, +}; + +static void btrfs_fs_info_release(struct kobject *kobj) +{ + struct btrfs_fs_info *fs_info; + fs_info = container_of(kobj, struct btrfs_fs_info, super_kobj); + complete(&fs_info->kobj_unregister); +} + +static ssize_t btrfs_attr_show(struct kobject *kobj, + struct attribute *attr, char *buf) +{ + struct btrfs_attr *a = container_of(attr, struct btrfs_attr, attr); + struct btrfs_fs_info *fs_info; + fs_info = container_of(kobj, struct btrfs_fs_info, super_kobj); + + return a->show ? a->show(a, fs_info, buf) : 0; +} + +static ssize_t btrfs_attr_store(struct kobject *kobj, + struct attribute *attr, + const char *buf, size_t len) +{ + struct btrfs_attr *a = container_of(attr, struct btrfs_attr, attr); + struct btrfs_fs_info *fs_info; + fs_info = container_of(kobj, struct btrfs_fs_info, super_kobj); + + return a->store ? a->store(a, fs_info, buf, len) : 0; +} + +static const struct sysfs_ops btrfs_attr_ops = { + .show = btrfs_attr_show, + .store = btrfs_attr_store, +}; + +static struct kobj_type btrfs_ktype = { + .default_attrs = btrfs_attrs, + .sysfs_ops = &btrfs_attr_ops, + .release = btrfs_fs_info_release, +}; + +int btrfs_sysfs_add_one(struct btrfs_fs_info *fs_info) +{ + init_completion(&fs_info->kobj_unregister); + fs_info->super_kobj.kset = btrfs_kset; + return kobject_init_and_add(&fs_info->super_kobj, &btrfs_ktype, NULL, + "%pU", fs_info->fsid); +} + +void btrfs_sysfs_remove_one(struct btrfs_fs_info *fs_info) +{ + kobject_del(&fs_info->super_kobj); + kobject_put(&fs_info->super_kobj); + wait_for_completion(&fs_info->kobj_unregister); +} + static void btrfs_supp_feat_release(struct kobject *kobj) { complete(&btrfs_feat->f_kobj_unregister); --- a/fs/btrfs/sysfs.h 2013-09-10 00:09:13.002087628 -0400 +++ b/fs/btrfs/sysfs.h 2013-09-10 00:09:35.525794464 -0400 @@ -8,6 +8,24 @@ enum btrfs_feature_set { FEAT_MAX }; +struct btrfs_attr { + struct attribute attr; + ssize_t (*show)(struct btrfs_attr *, struct btrfs_fs_info *, char *); + ssize_t (*store)(struct btrfs_attr *, struct btrfs_fs_info *, + const char *, size_t); +}; + +#define __INIT_BTRFS_ATTR(_name, _mode, _show, _store) \ +{ \ + .attr = { .name = __stringify(_name), .mode = _mode }, \ + .show = _show, \ + .store = _store, \ +} + +#define BTRFS_ATTR(_name, _mode, _show, _store) \ +static struct btrfs_attr btrfs_attr_##_name = \ + __INIT_BTRFS_ATTR(_name, _mode, _show, _store) + struct btrfs_feature_attr { struct attribute attr; /* global show, no store */ enum btrfs_feature_set feature_set; @@ -31,6 +49,7 @@ static struct btrfs_feature_attr btrfs_a #define BTRFS_SUPP_FEAT_LIST(_name) (&btrfs_attr_##_name.attr), /* convert from attribute */ +#define to_btrfs_attr(a) container_of(a, struct btrfs_attr, attr) #define to_btrfs_feature_attr(a) \ container_of(a, struct btrfs_feature_attr, attr)