Commit 02e3cc70 authored by Steven Whitehouse's avatar Steven Whitehouse Committed by Steven Whitehouse
Browse files

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: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent f15ab561

fs/gfs2/incore.h

+1 −0
Original line number Diff line number Diff line
@@ -470,6 +470,7 @@ struct gfs2_sb_host { 


	char sb_lockproto[GFS2_LOCKNAME_LEN];

	char sb_locktable[GFS2_LOCKNAME_LEN];

	u8 sb_uuid[16];

};



/*

fs/gfs2/ops_fstype.c

+1 −0
Original line number Diff line number Diff line
@@ -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);

}



/**

fs/gfs2/sys.c

+37 −0
Original line number Diff line number Diff line
@@ -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;

}

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