From: Mikulas Patocka <mpatocka@redhat.com> stable inclusion from stable-4.19.246 commit fdf6803caf6ebd94f9ead27f888073c4def13715 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I5FNPY CVE: NA -------------------------------- commit bfe2b0146c4d0230b68f5c71a64380ff8d361f8b upstream. dm-stats can be used with a very large number of entries (it is only limited by 1/4 of total system memory), so add rescheduling points to the loops that iterate over the entries. Cc: stable@vger.kernel.org Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> Signed-off-by: Laibin Qiu <qiulaibin@huawei.com> --- drivers/md/dm-stats.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/md/dm-stats.c b/drivers/md/dm-stats.c index 21de30b4e2a1..3d59f3e208c5 100644 --- a/drivers/md/dm-stats.c +++ b/drivers/md/dm-stats.c @@ -224,6 +224,7 @@ void dm_stats_cleanup(struct dm_stats *stats) atomic_read(&shared->in_flight[READ]), atomic_read(&shared->in_flight[WRITE])); } + cond_resched(); } dm_stat_free(&s->rcu_head); } @@ -313,6 +314,7 @@ static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end, for (ni = 0; ni < n_entries; ni++) { atomic_set(&s->stat_shared[ni].in_flight[READ], 0); atomic_set(&s->stat_shared[ni].in_flight[WRITE], 0); + cond_resched(); } if (s->n_histogram_entries) { @@ -325,6 +327,7 @@ static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end, for (ni = 0; ni < n_entries; ni++) { s->stat_shared[ni].tmp.histogram = hi; hi += s->n_histogram_entries + 1; + cond_resched(); } } @@ -345,6 +348,7 @@ static int dm_stats_create(struct dm_stats *stats, sector_t start, sector_t end, for (ni = 0; ni < n_entries; ni++) { p[ni].histogram = hi; hi += s->n_histogram_entries + 1; + cond_resched(); } } } @@ -474,6 +478,7 @@ static int dm_stats_list(struct dm_stats *stats, const char *program, } DMEMIT("\n"); } + cond_resched(); } mutex_unlock(&stats->mutex); @@ -750,6 +755,7 @@ static void __dm_stat_clear(struct dm_stat *s, size_t idx_start, size_t idx_end, local_irq_enable(); } } + cond_resched(); } } @@ -865,6 +871,8 @@ static int dm_stats_print(struct dm_stats *stats, int id, if (unlikely(sz + 1 >= maxlen)) goto buffer_overflow; + + cond_resched(); } if (clear) -- 2.25.1