[GFS2] Tidy up locking code

As per Jan Engelhardt's second email, this removes some unused code,
and fixes up indenting in various places.

Cc: Jan Engelhardt <jengelh@linux01.gwdg.de>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/glock.c

@@ -300,8 +300,7 @@ int gfs2_glock_get(struct gfs2_sbd *sdp, uint64_t number,
 
 	/* If this glock protects actual on-disk data or metadata blocks,
 	   create a VFS inode to manage the pages/buffers holding them. */
-	if (glops == &gfs2_inode_glops ||
+	if (glops == &gfs2_inode_glops || glops == &gfs2_rgrp_glops) {
-	    glops == &gfs2_rgrp_glops) {
 		gl->gl_aspace = gfs2_aspace_get(sdp);
 		if (!gl->gl_aspace) {
 			error = -ENOMEM;
@@ -820,13 +819,11 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
 
 	if (!gh)
 		gl->gl_stamp = jiffies;
-
 	else if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags))) {
 		spin_lock(&gl->gl_spin);
 		list_del_init(&gh->gh_list);
 		gh->gh_error = -EIO;
 		spin_unlock(&gl->gl_spin);
-
 	} else if (test_bit(HIF_DEMOTE, &gh->gh_iflags)) {
 		spin_lock(&gl->gl_spin);
 		list_del_init(&gh->gh_list);
@@ -842,7 +839,7 @@ static void xmote_bh(struct gfs2_glock *gl, unsigned int ret)
 		spin_unlock(&gl->gl_spin);
 
 		if (ret & LM_OUT_CANCELED)
-			handle_callback(gl, LM_ST_UNLOCKED); /* Lame */
+			handle_callback(gl, LM_ST_UNLOCKED);
 
 	} else if (ret & LM_OUT_CANCELED) {
 		spin_lock(&gl->gl_spin);
@@ -916,11 +913,8 @@ void gfs2_glock_xmote_th(struct gfs2_glock *gl, unsigned int state, int flags)
 	gfs2_assert_warn(sdp, state != LM_ST_UNLOCKED);
 	gfs2_assert_warn(sdp, state != gl->gl_state);
 
-	if (gl->gl_state == LM_ST_EXCLUSIVE) {
+	if (gl->gl_state == LM_ST_EXCLUSIVE && glops->go_sync)
-		if (glops->go_sync)
+		glops->go_sync(gl, DIO_METADATA | DIO_DATA | DIO_RELEASE);
-			glops->go_sync(gl,
-				       DIO_METADATA | DIO_DATA | DIO_RELEASE);
-	}
 
 	gfs2_glock_hold(gl);
 	gl->gl_req_bh = xmote_bh;
@@ -1006,10 +1000,8 @@ void gfs2_glock_drop_th(struct gfs2_glock *gl)
 	gfs2_assert_warn(sdp, queue_empty(gl, &gl->gl_holders));
 	gfs2_assert_warn(sdp, gl->gl_state != LM_ST_UNLOCKED);
 
-	if (gl->gl_state == LM_ST_EXCLUSIVE) {
+	if (gl->gl_state == LM_ST_EXCLUSIVE && glops->go_sync)
-		if (glops->go_sync)
+		glops->go_sync(gl, DIO_METADATA | DIO_DATA | DIO_RELEASE);
-			glops->go_sync(gl, DIO_METADATA | DIO_DATA | DIO_RELEASE);
-	}
 
 	gfs2_glock_hold(gl);
 	gl->gl_req_bh = drop_bh;
@@ -1041,9 +1033,8 @@ static void do_cancels(struct gfs2_holder *gh)
 	while (gl->gl_req_gh != gh &&
 	       !test_bit(HIF_HOLDER, &gh->gh_iflags) &&
 	       !list_empty(&gh->gh_list)) {
-		if (gl->gl_req_bh &&
+		if (gl->gl_req_bh && !(gl->gl_req_gh &&
-		    !(gl->gl_req_gh &&
+				     (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) {
-		      (gl->gl_req_gh->gh_flags & GL_NOCANCEL))) {
 			spin_unlock(&gl->gl_spin);
 			gfs2_lm_cancel(gl->gl_sbd, gl->gl_lock);
 			msleep(100);
@@ -1323,10 +1314,8 @@ static void gfs2_glock_prefetch(struct gfs2_glock *gl, unsigned int state,
 
 	spin_lock(&gl->gl_spin);
 
-	if (test_bit(GLF_LOCK, &gl->gl_flags) ||
+	if (test_bit(GLF_LOCK, &gl->gl_flags) || !list_empty(&gl->gl_holders) ||
-	    !list_empty(&gl->gl_holders) ||
+	    !list_empty(&gl->gl_waiters1) || !list_empty(&gl->gl_waiters2) ||
-	    !list_empty(&gl->gl_waiters1) ||
-	    !list_empty(&gl->gl_waiters2) ||
 	    !list_empty(&gl->gl_waiters3) ||
 	    relaxed_state_ok(gl->gl_state, state, flags)) {
 		spin_unlock(&gl->gl_spin);
@@ -1690,19 +1679,6 @@ void gfs2_lvb_unhold(struct gfs2_glock *gl)
 	gfs2_glock_put(gl);
 }
 
-#if 0
-void gfs2_lvb_sync(struct gfs2_glock *gl)
-{
-	gfs2_glmutex_lock(gl);
-
-	gfs2_assert(gl->gl_sbd, atomic_read(&gl->gl_lvb_count));
-	if (!gfs2_assert_warn(gl->gl_sbd, gfs2_glock_is_held_excl(gl)))
-		gfs2_lm_sync_lvb(gl->gl_sbd, gl->gl_lock, gl->gl_lvb);
-
-	gfs2_glmutex_unlock(gl);
-}
-#endif  /*  0  */
-
 static void blocking_cb(struct gfs2_sbd *sdp, struct lm_lockname *name,
 			unsigned int state)
 {
@@ -1813,8 +1789,7 @@ static int demote_ok(struct gfs2_glock *gl)
 	if (test_bit(GLF_STICKY, &gl->gl_flags))
 		demote = 0;
 	else if (test_bit(GLF_PREFETCH, &gl->gl_flags))
-		demote = time_after_eq(jiffies,
+		demote = time_after_eq(jiffies, gl->gl_stamp +
-				    gl->gl_stamp +
 				    gfs2_tune_get(sdp, gt_prefetch_secs) * HZ);
 	else if (glops->go_demote_ok)
 		demote = glops->go_demote_ok(gl);
@@ -1872,8 +1847,7 @@ void gfs2_reclaim_glock(struct gfs2_sbd *sdp)
 
 	if (gfs2_glmutex_trylock(gl)) {
 		if (queue_empty(gl, &gl->gl_holders) &&
-		    gl->gl_state != LM_ST_UNLOCKED &&
+		    gl->gl_state != LM_ST_UNLOCKED && demote_ok(gl))
-		    demote_ok(gl))
 			handle_callback(gl, LM_ST_UNLOCKED);
 		gfs2_glmutex_unlock(gl);
 	}
@@ -2036,8 +2010,7 @@ void gfs2_gl_hash_clear(struct gfs2_sbd *sdp, int wait)
 		cont = 0;
 
 		for (x = 0; x < GFS2_GL_HASH_SIZE; x++)
-			if (examine_bucket(clear_glock, sdp,
+			if (examine_bucket(clear_glock, sdp, &sdp->sd_gl_hash[x]))
-					   &sdp->sd_gl_hash[x]))
 				cont = 1;
 
 		if (!wait || !cont)

fs/gfs2/glock.h

@@ -51,17 +51,17 @@ static inline int gfs2_glock_is_locked_by_me(struct gfs2_glock *gl)
 
 static inline int gfs2_glock_is_held_excl(struct gfs2_glock *gl)
 {
-	return (gl->gl_state == LM_ST_EXCLUSIVE);
+	return gl->gl_state == LM_ST_EXCLUSIVE;
 }
 
 static inline int gfs2_glock_is_held_dfrd(struct gfs2_glock *gl)
 {
-	return (gl->gl_state == LM_ST_DEFERRED);
+	return gl->gl_state == LM_ST_DEFERRED;
 }
 
 static inline int gfs2_glock_is_held_shrd(struct gfs2_glock *gl)
 {
-	return (gl->gl_state == LM_ST_SHARED);
+	return gl->gl_state == LM_ST_SHARED;
 }
 
 static inline int gfs2_glock_is_blocking(struct gfs2_glock *gl)

fs/gfs2/lm.c

@@ -124,10 +124,8 @@ int gfs2_lm_withdraw(struct gfs2_sbd *sdp, char *fmt, ...)
 int gfs2_lm_get_lock(struct gfs2_sbd *sdp, struct lm_lockname *name,
 		     lm_lock_t **lockp)
 {
-	int error;
+	int error = -EIO;
-	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		error = -EIO;
-	else
 		error = sdp->sd_lockstruct.ls_ops->lm_get_lock(
 				sdp->sd_lockstruct.ls_lockspace, name, lockp);
 	return error;
@@ -143,12 +141,9 @@ unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, lm_lock_t *lock,
 			  unsigned int cur_state, unsigned int req_state,
 			  unsigned int flags)
 {
-	int ret;
+	int ret = 0;
-	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		ret = 0;
+		ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock, cur_state,
-	else
-		ret = sdp->sd_lockstruct.ls_ops->lm_lock(lock,
-							 cur_state,
 							 req_state, flags);
 	return ret;
 }
@@ -156,10 +151,8 @@ unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, lm_lock_t *lock,
 unsigned int gfs2_lm_unlock(struct gfs2_sbd *sdp, lm_lock_t *lock,
 			    unsigned int cur_state)
 {
-	int ret;
+	int ret = 0;
-	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		ret = 0;
-	else
 		ret =  sdp->sd_lockstruct.ls_ops->lm_unlock(lock, cur_state);
 	return ret;
 }
@@ -172,10 +165,8 @@ void gfs2_lm_cancel(struct gfs2_sbd *sdp, lm_lock_t *lock)
 
 int gfs2_lm_hold_lvb(struct gfs2_sbd *sdp, lm_lock_t *lock, char **lvbp)
 {
-	int error;
+	int error = -EIO;
-	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		error = -EIO;
-	else
 		error = sdp->sd_lockstruct.ls_ops->lm_hold_lvb(lock, lvbp);
 	return error;
 }
@@ -186,50 +177,33 @@ void gfs2_lm_unhold_lvb(struct gfs2_sbd *sdp, lm_lock_t *lock, char *lvb)
 		sdp->sd_lockstruct.ls_ops->lm_unhold_lvb(lock, lvb);
 }
 
-#if 0
-void gfs2_lm_sync_lvb(struct gfs2_sbd *sdp, lm_lock_t *lock, char *lvb)
-{
-	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		sdp->sd_lockstruct.ls_ops->lm_sync_lvb(lock, lvb);
-}
-#endif  /*  0  */
-
 int gfs2_lm_plock_get(struct gfs2_sbd *sdp, struct lm_lockname *name,
 		      struct file *file, struct file_lock *fl)
 {
-	int error;
+	int error = -EIO;
-	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		error = -EIO;
-	else
 		error = sdp->sd_lockstruct.ls_ops->lm_plock_get(
-			sdp->sd_lockstruct.ls_lockspace,
+				sdp->sd_lockstruct.ls_lockspace, name, file, fl);
-			name, file, fl);
 	return error;
 }
 
 int gfs2_lm_plock(struct gfs2_sbd *sdp, struct lm_lockname *name,
 		  struct file *file, int cmd, struct file_lock *fl)
 {
-	int error;
+	int error = -EIO;
-	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		error = -EIO;
-	else
 		error = sdp->sd_lockstruct.ls_ops->lm_plock(
-			sdp->sd_lockstruct.ls_lockspace,
+				sdp->sd_lockstruct.ls_lockspace, name, file, cmd, fl);
-			name, file, cmd, fl);
 	return error;
 }
 
 int gfs2_lm_punlock(struct gfs2_sbd *sdp, struct lm_lockname *name,
 		    struct file *file, struct file_lock *fl)
 {
-	int error;
+	int error = -EIO;
-	if (unlikely(test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
+	if (likely(!test_bit(SDF_SHUTDOWN, &sdp->sd_flags)))
-		error = -EIO;
-	else
 		error = sdp->sd_lockstruct.ls_ops->lm_punlock(
-			sdp->sd_lockstruct.ls_lockspace,
+				sdp->sd_lockstruct.ls_lockspace, name, file, fl);
-			name, file, fl);
 	return error;
 }
 

fs/gfs2/lm.h

@@ -16,9 +16,9 @@ int gfs2_lm_mount(struct gfs2_sbd *sdp, int silent);
 void gfs2_lm_others_may_mount(struct gfs2_sbd *sdp);
 void gfs2_lm_unmount(struct gfs2_sbd *sdp);
 int gfs2_lm_withdraw(struct gfs2_sbd *sdp, char *fmt, ...)
-__attribute__ ((format(printf, 2, 3)));
+				__attribute__ ((format(printf, 2, 3)));
-int gfs2_lm_get_lock(struct gfs2_sbd *sdp,
+int gfs2_lm_get_lock(struct gfs2_sbd *sdp, struct lm_lockname *name,
-		    struct lm_lockname *name, lm_lock_t **lockp);
+		     lm_lock_t **lockp);
 void gfs2_lm_put_lock(struct gfs2_sbd *sdp, lm_lock_t *lock);
 unsigned int gfs2_lm_lock(struct gfs2_sbd *sdp, lm_lock_t *lock,
 			 unsigned int cur_state, unsigned int req_state,
@@ -28,16 +28,13 @@ unsigned int gfs2_lm_unlock(struct gfs2_sbd *sdp, lm_lock_t *lock,
 void gfs2_lm_cancel(struct gfs2_sbd *sdp, lm_lock_t *lock);
 int gfs2_lm_hold_lvb(struct gfs2_sbd *sdp, lm_lock_t *lock, char **lvbp);
 void gfs2_lm_unhold_lvb(struct gfs2_sbd *sdp, lm_lock_t *lock, char *lvb);
-int gfs2_lm_plock_get(struct gfs2_sbd *sdp,
+int gfs2_lm_plock_get(struct gfs2_sbd *sdp, struct lm_lockname *name,
-		     struct lm_lockname *name,
+		      struct file *file, struct file_lock *fl);
-		     struct file *file, struct file_lock *fl);
+int gfs2_lm_plock(struct gfs2_sbd *sdp, struct lm_lockname *name,
-int gfs2_lm_plock(struct gfs2_sbd *sdp,
+		  struct file *file, int cmd, struct file_lock *fl);
-		 struct lm_lockname *name,
+int gfs2_lm_punlock(struct gfs2_sbd *sdp, struct lm_lockname *name,
-		 struct file *file, int cmd, struct file_lock *fl);
+		    struct file *file, struct file_lock *fl);
-int gfs2_lm_punlock(struct gfs2_sbd *sdp,
+void gfs2_lm_recovery_done(struct gfs2_sbd *sdp, unsigned int jid,
-		   struct lm_lockname *name,
+			   unsigned int message);
-		   struct file *file, struct file_lock *fl);
-void gfs2_lm_recovery_done(struct gfs2_sbd *sdp,
-			  unsigned int jid, unsigned int message);
 
 #endif /* __LM_DOT_H__ */

fs/gfs2/lm_interface.h

@@ -260,8 +260,6 @@ struct lm_lockstruct {
 	int ls_flags;
 };
 
-void __init gfs2_init_lmh(void);
-
 /*
  * Lock module bottom interface.  A lock module makes itself available to GFS
  * with these functions.

fs/gfs2/locking.c

@@ -27,8 +27,8 @@ struct lmh_wrapper {
 /* List of registered low-level locking protocols.  A file system selects one
    of them by name at mount time, e.g. lock_nolock, lock_dlm. */
 
-static struct list_head lmh_list;
+static LIST_HEAD(lmh_list);
-static struct mutex lmh_lock;
+static DEFINE_MUTEX(lmh_lock);
 
 /**
  * gfs2_register_lockproto - Register a low-level locking protocol
@@ -180,12 +180,6 @@ void gfs2_withdraw_lockproto(struct lm_lockstruct *lockstruct)
 	mutex_unlock(&lmh_lock);
 }
 
-void __init gfs2_init_lmh(void)
-{
-	mutex_init(&lmh_lock);
-	INIT_LIST_HEAD(&lmh_list);
-}
-
 EXPORT_SYMBOL_GPL(gfs2_register_lockproto);
 EXPORT_SYMBOL_GPL(gfs2_unregister_lockproto);
 

fs/gfs2/main.c

@@ -65,8 +65,6 @@ static int __init init_gfs2_fs(void)
 {
 	int error;
 
-	gfs2_init_lmh();
-
 	error = gfs2_sys_init();
 	if (error)
 		return error;