btrfs: print process name and pid that calls device scanning

Its very helpful if we had logged the device scanner process name to
debug the race condition between the systemd-udevd scan and the user
initiated device forget command.

This patch adds process name and pid to the scan message.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add pid to the message ]
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index f7b45e4..139b73d 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1005,11 +1005,15 @@ static noinline struct btrfs_device *device_list_add(const char *path,
                *new_device_added = true;
 
                if (disk_super->label[0])
-                       pr_info("BTRFS: device label %s devid %llu transid %llu %s\n",
-                               disk_super->label, devid, found_transid, path);
+                       pr_info(
+       "BTRFS: device label %s devid %llu transid %llu %s scanned by %s (%d)\n",
+                               disk_super->label, devid, found_transid, path,
+                               current->comm, task_pid_nr(current));
                else
-                       pr_info("BTRFS: device fsid %pU devid %llu transid %llu %s\n",
-                               disk_super->fsid, devid, found_transid, path);
+                       pr_info(
+       "BTRFS: device fsid %pU devid %llu transid %llu %s scanned by %s (%d)\n",
+                               disk_super->fsid, devid, found_transid, path,
+                               current->comm, task_pid_nr(current));
 
        } else if (!device->name || strcmp(device->name->str, path)) {
                /*