From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-it0-f67.google.com ([209.85.214.67]:38452 "EHLO mail-it0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933556AbeEICHy (ORCPT ); Tue, 8 May 2018 22:07:54 -0400 Received: by mail-it0-f67.google.com with SMTP id q4-v6so18719429ite.3 for ; Tue, 08 May 2018 19:07:53 -0700 (PDT) From: Howard McLauchlan To: linux-btrfs@vger.kernel.org Cc: Chris Mason , Josef Bacik , David Sterba , Filipe Manana , Omar Sandoval , Filipe David Borba Manana , Howard McLauchlan Subject: [RFC PATCH 5/6] btrfs: add send_stream_version attribute to sysfs Date: Tue, 8 May 2018 22:06:50 -0400 Message-Id: <20180509020651.7946-6-linux@hmclauchlan.com> In-Reply-To: <20180509020651.7946-1-linux@hmclauchlan.com> References: <20180509020651.7946-1-linux@hmclauchlan.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: From: Filipe David Borba Manana So that applications can find out what's the highest send stream version supported/implemented by the running kernel: $ cat /sys/fs/btrfs/send/stream_version 2 [Howard: rebased on 4.17-rc4] Signed-off-by: Howard McLauchlan Signed-off-by: Filipe David Borba Manana Reviewed-by: David Sterba --- fs/btrfs/send.h | 1 + fs/btrfs/sysfs.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h index a5830d216ac1..2f5e25e03def 100644 --- a/fs/btrfs/send.h +++ b/fs/btrfs/send.h @@ -12,6 +12,7 @@ #define BTRFS_SEND_STREAM_MAGIC "btrfs-stream" #define BTRFS_SEND_STREAM_VERSION_1 1 #define BTRFS_SEND_STREAM_VERSION_2 2 +#define BTRFS_SEND_STREAM_VERSION_LATEST BTRFS_SEND_STREAM_VERSION_2 #define BTRFS_SEND_BUF_SIZE SZ_64K #define BTRFS_SEND_READ_SIZE (48 * SZ_1K) diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 4848a4318fb5..3c82cba91ff6 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -18,6 +18,7 @@ #include "transaction.h" #include "sysfs.h" #include "volumes.h" +#include "send.h" static inline struct btrfs_fs_info *to_fs_info(struct kobject *kobj); static inline struct btrfs_fs_devices *to_fs_devs(struct kobject *kobj); @@ -884,6 +885,28 @@ static int btrfs_init_debugfs(void) return 0; } +static ssize_t send_stream_version_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%d\n", + BTRFS_SEND_STREAM_VERSION_LATEST); +} + +BTRFS_ATTR(, stream_version, send_stream_version_show); + +static struct attribute *btrfs_send_attrs[] = { + BTRFS_ATTR_PTR(, stream_version), + NULL +}; + +static const struct attribute_group btrfs_send_attr_group = { + .name = "send", + .attrs = btrfs_send_attrs, +}; + + + int __init btrfs_init_sysfs(void) { int ret; @@ -900,8 +923,13 @@ int __init btrfs_init_sysfs(void) ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); if (ret) goto out2; + ret = sysfs_create_group(&btrfs_kset->kobj, &btrfs_send_attr_group); + if (ret) + goto out3; return 0; +out3: + sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); out2: debugfs_remove_recursive(btrfs_debugfs_root_dentry); out1: @@ -913,6 +941,7 @@ int __init btrfs_init_sysfs(void) void __cold btrfs_exit_sysfs(void) { sysfs_remove_group(&btrfs_kset->kobj, &btrfs_feature_attr_group); + sysfs_remove_group(&btrfs_kset->kobj, &btrfs_send_attr_group); kset_unregister(btrfs_kset); debugfs_remove_recursive(btrfs_debugfs_root_dentry); } -- 2.17.0