gfs2: Split the two kinds of glock "delete" work

Function delete_work_func() is used for two purposes:

 * to immediately try to evict the glock's inode, and

 * to verify after a little while that the inode has been deleted as
   expected, and didn't just get skipped.

These two operations are not separated very well, so introduce two new
glock flags to improved that.  Split gfs2_queue_delete_work() into
gfs2_queue_try_to_evict and gfs2_queue_verify_evict().
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/glock.c

@@ -975,6 +975,26 @@ static bool gfs2_try_evict(struct gfs2_glock *gl)
 	return evicted;
 }
 
+bool gfs2_queue_try_to_evict(struct gfs2_glock *gl)
+{
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
+
+	if (test_and_set_bit(GLF_TRY_TO_EVICT, &gl->gl_flags))
+		return false;
+	return queue_delayed_work(sdp->sd_delete_wq,
+				  &gl->gl_delete, 0);
+}
+
+static bool gfs2_queue_verify_evict(struct gfs2_glock *gl)
+{
+	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
+
+	if (test_and_set_bit(GLF_VERIFY_EVICT, &gl->gl_flags))
+		return false;
+	return queue_delayed_work(sdp->sd_delete_wq,
+				  &gl->gl_delete, 5 * HZ);
+}
+
 static void delete_work_func(struct work_struct *work)
 {
 	struct delayed_work *dwork = to_delayed_work(work);
@@ -983,7 +1003,7 @@ static void delete_work_func(struct work_struct *work)
 	struct inode *inode;
 	u64 no_addr = gl->gl_name.ln_number;
 
-	if (test_bit(GLF_DEMOTE, &gl->gl_flags)) {
+	if (test_and_clear_bit(GLF_TRY_TO_EVICT, &gl->gl_flags)) {
 		/*
 		 * If we can evict the inode, give the remote node trying to
 		 * delete the inode some time before verifying that the delete
@@ -1002,22 +1022,25 @@ static void delete_work_func(struct work_struct *work)
 		 * step entirely.
 		 */
 		if (gfs2_try_evict(gl)) {
-			if (gfs2_queue_delete_work(gl, 5 * HZ))
+			if (gfs2_queue_verify_evict(gl))
 				return;
 		}
 		goto out;
 	}
 
-	inode = gfs2_lookup_by_inum(sdp, no_addr, gl->gl_no_formal_ino,
-				    GFS2_BLKST_UNLINKED);
-	if (IS_ERR(inode)) {
-		if (PTR_ERR(inode) == -EAGAIN &&
-			(gfs2_queue_delete_work(gl, 5 * HZ)))
+	if (test_and_clear_bit(GLF_VERIFY_EVICT, &gl->gl_flags)) {
+		inode = gfs2_lookup_by_inum(sdp, no_addr, gl->gl_no_formal_ino,
+					    GFS2_BLKST_UNLINKED);
+		if (IS_ERR(inode)) {
+			if (PTR_ERR(inode) == -EAGAIN &&
+			    gfs2_queue_verify_evict(gl))
 				return;
-	} else {
-		d_prune_aliases(inode);
-		iput(inode);
+		} else {
+			d_prune_aliases(inode);
+			iput(inode);
+		}
 	}
+
 out:
 	gfs2_glock_put(gl);
 }
@@ -2057,16 +2080,10 @@ static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp)
 	rhashtable_walk_exit(&iter);
 }
 
-bool gfs2_queue_delete_work(struct gfs2_glock *gl, unsigned long delay)
-{
-	struct gfs2_sbd *sdp = gl->gl_name.ln_sbd;
-
-	return queue_delayed_work(sdp->sd_delete_wq,
-				  &gl->gl_delete, delay);
-}
-
 void gfs2_cancel_delete_work(struct gfs2_glock *gl)
 {
+	clear_bit(GLF_TRY_TO_EVICT, &gl->gl_flags);
+	clear_bit(GLF_VERIFY_EVICT, &gl->gl_flags);
 	if (cancel_delayed_work(&gl->gl_delete))
 		gfs2_glock_put(gl);
 }
@@ -2298,6 +2315,10 @@ static const char *gflags2str(char *buf, const struct gfs2_glock *gl)
 		*p++ = 'n';
 	if (test_bit(GLF_INSTANTIATE_IN_PROG, gflags))
 		*p++ = 'N';
+	if (test_bit(GLF_TRY_TO_EVICT, gflags))
+		*p++ = 'e';
+	if (test_bit(GLF_VERIFY_EVICT, gflags))
+		*p++ = 'E';
 	*p = 0;
 	return buf;
 }

fs/gfs2/glock.h

@@ -267,7 +267,7 @@ static inline int gfs2_glock_nq_init(struct gfs2_glock *gl,
 
 extern void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state);
 extern void gfs2_glock_complete(struct gfs2_glock *gl, int ret);
-extern bool gfs2_queue_delete_work(struct gfs2_glock *gl, unsigned long delay);
+extern bool gfs2_queue_try_to_evict(struct gfs2_glock *gl);
 extern void gfs2_cancel_delete_work(struct gfs2_glock *gl);
 extern void gfs2_flush_delete_work(struct gfs2_sbd *sdp);
 extern void gfs2_gl_hash_clear(struct gfs2_sbd *sdp);

fs/gfs2/glops.c

@@ -651,7 +651,7 @@ static void iopen_go_callback(struct gfs2_glock *gl, bool remote)
 	if (gl->gl_demote_state == LM_ST_UNLOCKED &&
 	    gl->gl_state == LM_ST_SHARED && ip) {
 		gl->gl_lockref.count++;
-		if (!gfs2_queue_delete_work(gl, 0))
+		if (!gfs2_queue_try_to_evict(gl))
 			gl->gl_lockref.count--;
 	}
 }

fs/gfs2/incore.h

@@ -330,6 +330,8 @@ enum {
 	GLF_OBJECT			= 14, /* Used only for tracing */
 	GLF_BLOCKING			= 15,
 	GLF_FREEING			= 16, /* Wait for glock to be freed */
+	GLF_TRY_TO_EVICT		= 17, /* iopen glocks only */
+	GLF_VERIFY_EVICT		= 18, /* iopen glocks only */
 };
 
 struct gfs2_glock {

fs/gfs2/rgrp.c

@@ -1879,7 +1879,7 @@ static void try_rgrp_unlink(struct gfs2_rgrpd *rgd, u64 *last_unlinked, u64 skip
 		 */
 		ip = gl->gl_object;
 
-		if (ip || !gfs2_queue_delete_work(gl, 0))
+		if (ip || !gfs2_queue_try_to_evict(gl))
 			gfs2_glock_put(gl);
 		else
 			found++;

fs/gfs2/super.c

@@ -954,7 +954,7 @@ static int gfs2_drop_inode(struct inode *inode)
 		struct gfs2_glock *gl = ip->i_iopen_gh.gh_gl;
 
 		gfs2_glock_hold(gl);
-		if (!gfs2_queue_delete_work(gl, 0))
+		if (!gfs2_queue_try_to_evict(gl))
 			gfs2_glock_queue_put(gl);
 		return 0;
 	}