xfs: check if an open file is on the health monitored fs

Source kernel commit: 8b85dc4090e1c72c6d42acd823514cce67cd54fc

Create a new ioctl for the healthmon file that checks that a given fd
points to the same filesystem that the healthmon file is monitoring.
This allows xfs_healer to check that when it reopens a mountpoint to
perform repairs, the file that it gets matches the filesystem that
generated the corruption report.

(Note that xfs_healer doesn't maintain an open fd to a filesystem that
it's monitoring so that it doesn't pin the mount.)

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/libxfs/xfs_fs.h b/libxfs/xfs_fs.h
index 4ec1b2aede976f6ddd72a2f23c8f2ba2d73a17ab..a01303c5de6ce614baa24f04ae181044383019c3 100644 (file)
--- a/libxfs/xfs_fs.h
+++ b/libxfs/xfs_fs.h
@@ -1151,6 +1151,15 @@ struct xfs_health_monitor {
 /* Initial return format version */
 #define XFS_HEALTH_MONITOR_FMT_V0      (0)
 
+/*
+ * Check that a given fd points to the same filesystem that the health monitor
+ * is monitoring.
+ */
+struct xfs_health_file_on_monitored_fs {
+       __s32           fd;
+       __u32           flags;  /* zero for now */
+};
+
 /*
  * ioctl commands that are used by Linux filesystems
  */
@@ -1191,7 +1200,8 @@ struct xfs_health_monitor {
 #define XFS_IOC_SCRUBV_METADATA        _IOWR('X', 64, struct xfs_scrub_vec_head)
 #define XFS_IOC_RTGROUP_GEOMETRY _IOWR('X', 65, struct xfs_rtgroup_geometry)
 #define XFS_IOC_HEALTH_MONITOR _IOW ('X', 68, struct xfs_health_monitor)
-
+#define XFS_IOC_HEALTH_FD_ON_MONITORED_FS \
+                               _IOW ('X', 69, struct xfs_health_file_on_monitored_fs)
 /*
  * ioctl commands that replace IRIX syssgi()'s
  */