add new system file

hc

2024-02-20 102a0743326a03cd1a1202ceda21e175b7d3575c

 kernel/drivers/md/dm-stats.c
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@@ -188,7 +188,7 @@
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 	       atomic_read(&shared->in_flight[WRITE]);
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 }
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-void dm_stats_init(struct dm_stats *stats)
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+int dm_stats_init(struct dm_stats *stats)
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 {
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 	int cpu;
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 	struct dm_stats_last_position *last;
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@@ -196,11 +196,16 @@
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 	mutex_init(&stats->mutex);
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 	INIT_LIST_HEAD(&stats->list);
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 	stats->last = alloc_percpu(struct dm_stats_last_position);
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+	if (!stats->last)
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+		return -ENOMEM;
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+
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 	for_each_possible_cpu(cpu) {
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 		last = per_cpu_ptr(stats->last, cpu);
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 		last->last_sector = (sector_t)ULLONG_MAX;
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 		last->last_rw = UINT_MAX;
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 	}
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+
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+	return 0;
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 }
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 void dm_stats_cleanup(struct dm_stats *stats)