gfs2: Keep track of deleted inode generations in LVBs

When deleting an inode, keep track of the generation of the deleted inode in
the inode glock Lock Value Block (LVB).  When trying to delete an inode
remotely, check the last-known inode generation against the deleted inode
generation to skip duplicate remote deletes.  This avoids taking the resource
group glock in order to verify the block type.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/fs/gfs2/glock.c b/fs/gfs2/glock.c
index 86e9e621f346..12681616eb76 100644
--- a/fs/gfs2/glock.c
+++ b/fs/gfs2/glock.c
@@ -755,6 +755,25 @@ out_unlock:
 	return;
 }
 
+void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation)
+{
+	struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr;
+
+	if (ri->ri_magic == 0)
+		ri->ri_magic = cpu_to_be32(GFS2_MAGIC);
+	if (ri->ri_magic == cpu_to_be32(GFS2_MAGIC))
+		ri->ri_generation_deleted = cpu_to_be64(generation);
+}
+
+bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation)
+{
+	struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr;
+
+	if (ri->ri_magic != cpu_to_be32(GFS2_MAGIC))
+		return false;
+	return generation <= be64_to_cpu(ri->ri_generation_deleted);
+}
+
 static void delete_work_func(struct work_struct *work)
 {
 	struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_delete);