GFS2: Improve statfs and quota usability

GFS2 now has three new mount options, statfs_quantum, quota_quantum and
statfs_percent.  statfs_quantum and quota_quantum simply allow you to
set the tunables of the same name.  Setting setting statfs_quantum to 0
will also turn on the statfs_slow tunable.  statfs_percent accepts an
integer between 0 and 100.  Numbers between 1 and 100 will cause GFS2 to
do any early sync when the local number of blocks free changes by at
least statfs_percent from the totoal number of blocks free.  Setting
statfs_percent to 0 disables this.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/incore.h

@@ -430,6 +430,9 @@ struct gfs2_args {
 	unsigned int ar_discard:1;		/* discard requests */
 	unsigned int ar_errors:2;               /* errors=withdraw | panic */
 	int ar_commit;				/* Commit interval */
+	int ar_statfs_quantum;			/* The fast statfs interval */
+	int ar_quota_quantum;			/* The quota interval */
+	int ar_statfs_percent;			/* The % change to force sync */
 };
 
 struct gfs2_tune {
@@ -558,6 +561,7 @@ struct gfs2_sbd {
 	spinlock_t sd_statfs_spin;
 	struct gfs2_statfs_change_host sd_statfs_master;
 	struct gfs2_statfs_change_host sd_statfs_local;
+	int sd_statfs_force_sync;
 
 	/* Resource group stuff */
 

fs/gfs2/ops_fstype.c

@@ -63,13 +63,10 @@ static void gfs2_tune_init(struct gfs2_tune *gt)
 	gt->gt_quota_warn_period = 10;
 	gt->gt_quota_scale_num = 1;
 	gt->gt_quota_scale_den = 1;
-	gt->gt_quota_quantum = 60;
 	gt->gt_new_files_jdata = 0;
 	gt->gt_max_readahead = 1 << 18;
 	gt->gt_stall_secs = 600;
 	gt->gt_complain_secs = 10;
-	gt->gt_statfs_quantum = 30;
-	gt->gt_statfs_slow = 0;
 }
 
 static struct gfs2_sbd *init_sbd(struct super_block *sb)
@@ -1153,6 +1150,15 @@ static int fill_super(struct super_block *sb, struct gfs2_args *args, int silent
 	sdp->sd_fsb2bb = 1 << sdp->sd_fsb2bb_shift;
 
 	sdp->sd_tune.gt_log_flush_secs = sdp->sd_args.ar_commit;
+	sdp->sd_tune.gt_quota_quantum = sdp->sd_args.ar_quota_quantum;
+	if (sdp->sd_args.ar_statfs_quantum) {
+		sdp->sd_tune.gt_statfs_slow = 0;
+		sdp->sd_tune.gt_statfs_quantum = sdp->sd_args.ar_statfs_quantum;
+	}
+	else {
+		sdp->sd_tune.gt_statfs_slow = 1;
+		sdp->sd_tune.gt_statfs_quantum = 30;
+	}
 
 	error = init_names(sdp, silent);
 	if (error)
@@ -1308,6 +1314,8 @@ static int gfs2_get_sb(struct file_system_type *fs_type, int flags,
 	args.ar_quota = GFS2_QUOTA_DEFAULT;
 	args.ar_data = GFS2_DATA_DEFAULT;
 	args.ar_commit = 60;
+	args.ar_statfs_quantum = 30;
+	args.ar_quota_quantum = 60;
 	args.ar_errors = GFS2_ERRORS_DEFAULT;
 
 	error = gfs2_mount_args(&args, data);

fs/gfs2/quota.c

@@ -1344,6 +1344,14 @@ static void quotad_check_trunc_list(struct gfs2_sbd *sdp)
 	}
 }
 
+void gfs2_wake_up_statfs(struct gfs2_sbd *sdp) {
+	if (!sdp->sd_statfs_force_sync) {
+		sdp->sd_statfs_force_sync = 1;
+		wake_up(&sdp->sd_quota_wait);
+	}
+}
+
+
 /**
  * gfs2_quotad - Write cached quota changes into the quota file
  * @sdp: Pointer to GFS2 superblock
@@ -1363,8 +1371,15 @@ int gfs2_quotad(void *data)
 	while (!kthread_should_stop()) {
 
 		/* Update the master statfs file */
-		quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
-				   &statfs_timeo, &tune->gt_statfs_quantum);
+		if (sdp->sd_statfs_force_sync) {
+			int error = gfs2_statfs_sync(sdp->sd_vfs, 0);
+			quotad_error(sdp, "statfs", error);
+			statfs_timeo = gfs2_tune_get(sdp, gt_statfs_quantum) * HZ;
+		}
+		else
+			quotad_check_timeo(sdp, "statfs", gfs2_statfs_sync, t,
+				   	   &statfs_timeo,
+					   &tune->gt_statfs_quantum);
 
 		/* Update quota file */
 		quotad_check_timeo(sdp, "sync", gfs2_quota_sync, t,
@@ -1381,7 +1396,7 @@ int gfs2_quotad(void *data)
 		spin_lock(&sdp->sd_trunc_lock);
 		empty = list_empty(&sdp->sd_trunc_list);
 		spin_unlock(&sdp->sd_trunc_lock);
-		if (empty)
+		if (empty && !sdp->sd_statfs_force_sync)
 			t -= schedule_timeout(t);
 		else
 			t = 0;

fs/gfs2/quota.h

@@ -32,6 +32,8 @@ extern int gfs2_quota_init(struct gfs2_sbd *sdp);
 extern void gfs2_quota_cleanup(struct gfs2_sbd *sdp);
 extern int gfs2_quotad(void *data);
 
+extern void gfs2_wake_up_statfs(struct gfs2_sbd *sdp);
+
 static inline int gfs2_quota_lock_check(struct gfs2_inode *ip)
 {
 	struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);

fs/gfs2/super.c

@@ -70,6 +70,9 @@ enum {
 	Opt_commit,
 	Opt_err_withdraw,
 	Opt_err_panic,
+	Opt_statfs_quantum,
+	Opt_statfs_percent,
+	Opt_quota_quantum,
 	Opt_error,
 };
 
@@ -101,6 +104,9 @@ static const match_table_t tokens = {
 	{Opt_commit, "commit=%d"},
 	{Opt_err_withdraw, "errors=withdraw"},
 	{Opt_err_panic, "errors=panic"},
+	{Opt_statfs_quantum, "statfs_quantum=%d"},
+	{Opt_statfs_percent, "statfs_percent=%d"},
+	{Opt_quota_quantum, "quota_quantum=%d"},
 	{Opt_error, NULL}
 };
 
@@ -214,6 +220,28 @@ int gfs2_mount_args(struct gfs2_args *args, char *options)
 				return rv ? rv : -EINVAL;
 			}
 			break;
+		case Opt_statfs_quantum:
+			rv = match_int(&tmp[0], &args->ar_statfs_quantum);
+			if (rv || args->ar_statfs_quantum < 0) {
+				printk(KERN_WARNING "GFS2: statfs_quantum mount option requires a non-negative numeric argument\n");
+				return rv ? rv : -EINVAL;
+			}
+			break;
+		case Opt_quota_quantum:
+			rv = match_int(&tmp[0], &args->ar_quota_quantum);
+			if (rv || args->ar_quota_quantum <= 0) {
+				printk(KERN_WARNING "GFS2: quota_quantum mount option requires a positive numeric argument\n");
+				return rv ? rv : -EINVAL;
+			}
+			break;
+		case Opt_statfs_percent:
+			rv = match_int(&tmp[0], &args->ar_statfs_percent);
+			if (rv || args->ar_statfs_percent < 0 ||
+			    args->ar_statfs_percent > 100) {
+				printk(KERN_WARNING "statfs_percent mount option requires a numeric argument between 0 and 100\n");
+				return rv ? rv : -EINVAL;
+			}
+			break;
 		case Opt_err_withdraw:
 			args->ar_errors = GFS2_ERRORS_WITHDRAW;
 			break;
@@ -442,7 +470,9 @@ void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
 {
 	struct gfs2_inode *l_ip = GFS2_I(sdp->sd_sc_inode);
 	struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
+	struct gfs2_statfs_change_host *m_sc = &sdp->sd_statfs_master;
 	struct buffer_head *l_bh;
+	int percent, sync_percent;
 	int error;
 
 	error = gfs2_meta_inode_buffer(l_ip, &l_bh);
@@ -456,9 +486,17 @@ void gfs2_statfs_change(struct gfs2_sbd *sdp, s64 total, s64 free,
 	l_sc->sc_free += free;
 	l_sc->sc_dinodes += dinodes;
 	gfs2_statfs_change_out(l_sc, l_bh->b_data + sizeof(struct gfs2_dinode));
+	if (m_sc->sc_free)
+		percent = (100 * l_sc->sc_free) / m_sc->sc_free;
+	else
+		percent = 100;
 	spin_unlock(&sdp->sd_statfs_spin);
 
 	brelse(l_bh);
+	sync_percent = sdp->sd_args.ar_statfs_percent;
+	if (sync_percent && (percent >= sync_percent ||
+			     percent <= -sync_percent))
+		gfs2_wake_up_statfs(sdp);
 }
 
 void update_statfs(struct gfs2_sbd *sdp, struct buffer_head *m_bh,
@@ -522,6 +560,7 @@ int gfs2_statfs_sync(struct super_block *sb, int type)
 		goto out_bh2;
 
 	update_statfs(sdp, m_bh, l_bh);
+	sdp->sd_statfs_force_sync = 0;
 
 	gfs2_trans_end(sdp);
 
@@ -1062,6 +1101,11 @@ static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data)
 
 	spin_lock(&gt->gt_spin);
 	args.ar_commit = gt->gt_log_flush_secs;
+	args.ar_quota_quantum = gt->gt_quota_quantum;
+	if (gt->gt_statfs_slow)
+		args.ar_statfs_quantum = 0;
+	else
+		args.ar_statfs_quantum = gt->gt_statfs_quantum;
 	spin_unlock(&gt->gt_spin);
 	error = gfs2_mount_args(&args, data);
 	if (error)
@@ -1100,6 +1144,15 @@ static int gfs2_remount_fs(struct super_block *sb, int *flags, char *data)
 		sb->s_flags &= ~MS_POSIXACL;
 	spin_lock(&gt->gt_spin);
 	gt->gt_log_flush_secs = args.ar_commit;
+	gt->gt_quota_quantum = args.ar_quota_quantum;
+	if (args.ar_statfs_quantum) {
+		gt->gt_statfs_slow = 0;
+		gt->gt_statfs_quantum = args.ar_statfs_quantum;
+	}
+	else {
+		gt->gt_statfs_slow = 1;
+		gt->gt_statfs_quantum = 30;
+	}
 	spin_unlock(&gt->gt_spin);
 
 	gfs2_online_uevent(sdp);
@@ -1180,7 +1233,7 @@ static int gfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
 {
 	struct gfs2_sbd *sdp = mnt->mnt_sb->s_fs_info;
 	struct gfs2_args *args = &sdp->sd_args;
-	int lfsecs;
+	int val;
 
 	if (is_ancestor(mnt->mnt_root, sdp->sd_master_dir))
 		seq_printf(s, ",meta");
@@ -1241,9 +1294,17 @@ static int gfs2_show_options(struct seq_file *s, struct vfsmount *mnt)
 	}
 	if (args->ar_discard)
 		seq_printf(s, ",discard");
-	lfsecs = sdp->sd_tune.gt_log_flush_secs;
-	if (lfsecs != 60)
-		seq_printf(s, ",commit=%d", lfsecs);
+	val = sdp->sd_tune.gt_log_flush_secs;
+	if (val != 60)
+		seq_printf(s, ",commit=%d", val);
+	val = sdp->sd_tune.gt_statfs_quantum;
+	if (val != 30)
+		seq_printf(s, ",statfs_quantum=%d", val);
+	val = sdp->sd_tune.gt_quota_quantum;
+	if (val != 60)
+		seq_printf(s, ",quota_quantum=%d", val);
+	if (args->ar_statfs_percent)
+		seq_printf(s, ",statfs_percent=%d", args->ar_statfs_percent);
 	if (args->ar_errors != GFS2_ERRORS_DEFAULT) {
 		const char *state;