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d3aa3e060c
Check alloc_precpu()'s return value and return an error from
dm_stats_init() if it fails. Update alloc_dev() to fail if
dm_stats_init() does.
Otherwise, a NULL pointer dereference will occur in dm_stats_cleanup()
even if dm-stats isn't being actively used.
Fixes: fd2ed4d252 ("dm: add statistics support")
Cc: stable@vger.kernel.org
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>
49 lines
1.1 KiB
C
49 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef DM_STATS_H
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#define DM_STATS_H
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#include <linux/types.h>
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#include <linux/mutex.h>
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#include <linux/list.h>
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int dm_statistics_init(void);
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void dm_statistics_exit(void);
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struct dm_stats {
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struct mutex mutex;
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struct list_head list; /* list of struct dm_stat */
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struct dm_stats_last_position __percpu *last;
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bool precise_timestamps;
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};
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struct dm_stats_aux {
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bool merged;
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unsigned long long duration_ns;
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};
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int dm_stats_init(struct dm_stats *st);
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void dm_stats_cleanup(struct dm_stats *st);
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struct mapped_device;
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int dm_stats_message(struct mapped_device *md, unsigned int argc, char **argv,
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char *result, unsigned int maxlen);
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void dm_stats_account_io(struct dm_stats *stats, unsigned long bi_rw,
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sector_t bi_sector, unsigned int bi_sectors, bool end,
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unsigned long start_time,
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struct dm_stats_aux *aux);
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static inline bool dm_stats_used(struct dm_stats *st)
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{
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return !list_empty(&st->list);
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}
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static inline void dm_stats_record_start(struct dm_stats *stats, struct dm_stats_aux *aux)
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{
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if (unlikely(stats->precise_timestamps))
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aux->duration_ns = ktime_to_ns(ktime_get());
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}
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#endif
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