From 02e3cc70ecbd4352ae4d26459929f43ab1547251 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Tue, 10 Feb 2009 13:48:30 +0000 Subject: [PATCH] GFS2: Expose UUID via sysfs/uevent Since we have a UUID, we ought to expose it to the user via sysfs and uevents. We already have the fs name in both of these places (a combination of the lock proto and lock table name) so if we add the UUID as well, we have a full set. For older filesystems (i.e. those created before mkfs.gfs2 was writing UUIDs by default) the sysfs file will appear zero length, and no UUID env var will be added to the uevents. Signed-off-by: Steven Whitehouse --- fs/gfs2/incore.h | 1 + fs/gfs2/ops_fstype.c | 1 + fs/gfs2/sys.c | 37 +++++++++++++++++++++++++++++++++++++ 3 files changed, 39 insertions(+) diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h index 3f29bd224ba..980a0864ca6 100644 --- a/fs/gfs2/incore.h +++ b/fs/gfs2/incore.h @@ -470,6 +470,7 @@ struct gfs2_sb_host { char sb_lockproto[GFS2_LOCKNAME_LEN]; char sb_locktable[GFS2_LOCKNAME_LEN]; + u8 sb_uuid[16]; }; /* diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index e502b379a4d..804ca7273a4 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -234,6 +234,7 @@ static void gfs2_sb_in(struct gfs2_sb_host *sb, const void *buf) memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN); memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN); + memcpy(sb->sb_uuid, str->sb_uuid, 16); } /** diff --git a/fs/gfs2/sys.c b/fs/gfs2/sys.c index a78997ea503..4d284d14980 100644 --- a/fs/gfs2/sys.c +++ b/fs/gfs2/sys.c @@ -36,6 +36,30 @@ static ssize_t fsname_show(struct gfs2_sbd *sdp, char *buf) return snprintf(buf, PAGE_SIZE, "%s\n", sdp->sd_fsname); } +static int gfs2_uuid_valid(const u8 *uuid) +{ + int i; + + for (i = 0; i < 16; i++) { + if (uuid[i]) + return 1; + } + return 0; +} + +static ssize_t uuid_show(struct gfs2_sbd *sdp, char *buf) +{ + const u8 *uuid = sdp->sd_sb.sb_uuid; + buf[0] = '\0'; + if (!gfs2_uuid_valid(uuid)) + return 0; + return snprintf(buf, PAGE_SIZE, "%02X%02X%02X%02X-%02X%02X-" + "%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X\n", + uuid[0], uuid[1], uuid[2], uuid[3], uuid[4], uuid[5], + uuid[6], uuid[7], uuid[8], uuid[9], uuid[10], uuid[11], + uuid[12], uuid[13], uuid[14], uuid[15]); +} + static ssize_t freeze_show(struct gfs2_sbd *sdp, char *buf) { unsigned int count; @@ -158,6 +182,7 @@ static struct gfs2_attr gfs2_attr_##name = __ATTR(name, mode, show, store) GFS2_ATTR(id, 0444, id_show, NULL); GFS2_ATTR(fsname, 0444, fsname_show, NULL); +GFS2_ATTR(uuid, 0444, uuid_show, NULL); GFS2_ATTR(freeze, 0644, freeze_show, freeze_store); GFS2_ATTR(withdraw, 0644, withdraw_show, withdraw_store); GFS2_ATTR(statfs_sync, 0200, NULL, statfs_sync_store); @@ -168,6 +193,7 @@ GFS2_ATTR(quota_refresh_group, 0200, NULL, quota_refresh_group_store); static struct attribute *gfs2_attrs[] = { &gfs2_attr_id.attr, &gfs2_attr_fsname.attr, + &gfs2_attr_uuid.attr, &gfs2_attr_freeze.attr, &gfs2_attr_withdraw.attr, &gfs2_attr_statfs_sync.attr, @@ -598,12 +624,23 @@ void gfs2_sys_fs_del(struct gfs2_sbd *sdp) kobject_put(&sdp->sd_kobj); } + static int gfs2_uevent(struct kset *kset, struct kobject *kobj, struct kobj_uevent_env *env) { struct gfs2_sbd *sdp = container_of(kobj, struct gfs2_sbd, sd_kobj); + const u8 *uuid = sdp->sd_sb.sb_uuid; + add_uevent_var(env, "LOCKTABLE=%s", sdp->sd_table_name); add_uevent_var(env, "LOCKPROTO=%s", sdp->sd_proto_name); + if (gfs2_uuid_valid(uuid)) { + add_uevent_var(env, "UUID=%02X%02X%02X%02X-%02X%02X-%02X%02X-" + "%02X%02X-%02X%02X%02X%02X%02X%02X", + uuid[0], uuid[1], uuid[2], uuid[3], uuid[4], + uuid[5], uuid[6], uuid[7], uuid[8], uuid[9], + uuid[10], uuid[11], uuid[12], uuid[13], + uuid[14], uuid[15]); + } return 0; } -- 2.41.1