GFS2: remove dcache entries for remote deleted inodes

When a file is deleted from a gfs2 filesystem on one node, a dcache
entry for it may still exist on other nodes in the cluster. If this
happens, gfs2 will be unable to free this file on disk. Because of this,
it's possible to have a gfs2 filesystem with no files on it and no free
space. With this patch, when a node receives a callback notifying it
that the file is being deleted on another node, it schedules a new
workqueue thread to remove the file's dcache entry.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/fs/gfs2/glops.c b/fs/gfs2/glops.c
index d5e4ab155ca0..6985eef06c39 100644
--- a/fs/gfs2/glops.c
+++ b/fs/gfs2/glops.c
@@ -323,6 +323,7 @@ static void trans_go_sync(struct gfs2_glock *gl)
 
         if (gl->gl_state != LM_ST_UNLOCKED &&
             test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags)) {
+                flush_workqueue(gfs2_delete_workqueue);
                 gfs2_meta_syncfs(sdp);
                 gfs2_log_shutdown(sdp);
         }
@@ -372,6 +373,25 @@ static int trans_go_demote_ok(const struct gfs2_glock *gl)
         return 0;
 }
 
+/**
+ * iopen_go_callback - schedule the dcache entry for the inode to be deleted
+ * @gl: the glock
+ *
+ * gl_spin lock is held while calling this
+ */
+static void iopen_go_callback(struct gfs2_glock *gl)
+{
+        struct gfs2_inode *ip = (struct gfs2_inode *)gl->gl_object;
+
+        if (gl->gl_demote_state == LM_ST_UNLOCKED &&
+            gl->gl_state == LM_ST_SHARED &&
+            ip && test_bit(GIF_USER, &ip->i_flags)) {
+                gfs2_glock_hold(gl);
+                if (queue_work(gfs2_delete_workqueue, &gl->gl_delete) == 0)
+                        gfs2_glock_put_nolock(gl);
+        }
+}
+
 const struct gfs2_glock_operations gfs2_meta_glops = {
         .go_type = LM_TYPE_META,
 };
@@ -406,6 +426,7 @@ const struct gfs2_glock_operations gfs2_trans_glops = {
 
 const struct gfs2_glock_operations gfs2_iopen_glops = {
         .go_type = LM_TYPE_IOPEN,
+        .go_callback = iopen_go_callback,
 };
 
 const struct gfs2_glock_operations gfs2_flock_glops = {