fs/quota: handle overflows of sysctl fs.quota.* and report as unsigned long

Quota statistics counted as 64-bit per-cpu counter. Reading sums per-cpu
fractions as signed 64-bit int, filters negative values and then reports
lower half as signed 32-bit int.

Result may looks like:

fs.quota.allocated_dquots = 22327
fs.quota.cache_hits = -489852115
fs.quota.drops = -487288718
fs.quota.free_dquots = 22083
fs.quota.lookups = -486883485
fs.quota.reads = 22327
fs.quota.syncs = 335064
fs.quota.writes = 3088689

Values bigger than 2^31-1 reported as negative.

All counters except "allocated_dquots" and "free_dquots" are monotonic,
thus they should be reported as is without filtering negative values.

Kernel doesn't have generic helper for 64-bit sysctl yet,
let's use at least unsigned long.

Link: https://lore.kernel.org/r/157337934693.2078.9842146413181153727.stgit@buzz
Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/quota.h b/include/linux/quota.h
index f32dd270b8e3..27aab84fcbaa 100644
--- a/include/linux/quota.h
+++ b/include/linux/quota.h
@@ -263,7 +263,7 @@ enum {
 };
 
 struct dqstats {
-	int stat[_DQST_DQSTAT_LAST];
+	unsigned long stat[_DQST_DQSTAT_LAST];
 	struct percpu_counter counter[_DQST_DQSTAT_LAST];
 };