[PATCH 2/4] xfs: send uevents when major filesystem events happen

["Darrick J. Wong" <djwong@kernel.org>]

From: Darrick J. Wong <djwong@kernel.org>

Send uevents when we mount, unmount, and shut down the filesystem, so
that we can trigger systemd services when major events happen.  This
enables us to create a udev rule that will start up xfs_healer whenever
a filesystem is mounted.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
 fs/xfs/xfs_fsops.c |    2 ++
 fs/xfs/xfs_super.c |   10 ++++++++++
 2 files changed, 12 insertions(+)


diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index b7c21f68edc78d..bd1022ecd2eb4c 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -27,6 +27,7 @@
 #include "xfs_metafile.h"
 
 #include <linux/fserror.h>
+#include <linux/fsevent.h>
 
 /*
  * Write new AG headers to disk. Non-transactional, but need to be
@@ -544,6 +545,7 @@ xfs_do_force_shutdown(
 		xfs_stack_trace();
 
 	fserror_report_shutdown(mp->m_super, GFP_KERNEL);
+	fsevent_send_shutdown(mp->m_super, &mp->m_kobj.kobject);
 }
 
 /*
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index bc71aa9dcee8d6..bd078c99389bc1 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -53,6 +53,8 @@
 #include <linux/magic.h>
 #include <linux/fs_context.h>
 #include <linux/fs_parser.h>
+#include <linux/uuid.h>
+#include <linux/fsevent.h>
 
 static const struct super_operations xfs_super_operations;
 
@@ -1249,6 +1251,8 @@ xfs_fs_put_super(
 {
 	struct xfs_mount	*mp = XFS_M(sb);
 
+	fsevent_send_unmount(mp->m_super, &mp->m_kobj.kobject);
+
 	xfs_notice(mp, "Unmounting Filesystem %pU", &mp->m_sb.sb_uuid);
 	xfs_filestream_unmount(mp);
 	xfs_unmountfs(mp);
@@ -1972,6 +1976,11 @@ xfs_fs_fill_super(
 		goto out_unmount;
 	}
 
+	/*
+	 * Send a uevent signalling that the mount succeeded so we can use udev
+	 * rules to start background services.
+	 */
+	fsevent_send_mount(mp->m_super, &mp->m_kobj.kobject, fc);
 	return 0;
 
  out_filestream_unmount:
@@ -2217,6 +2226,7 @@ xfs_fs_reconfigure(
 			return error;
 	}
 
+	fsevent_send_remount(mp->m_super, &mp->m_kobj.kobject);
 	return 0;
 }