PING: [PATCH] block: add io_error stat for block device

From: zhenwei pi
Date: Thu Sep 24 2020 - 23:55:34 EST


Hi, Jens

How do you think about error stat of a block device?

On 9/10/20 10:20 AM, zhenwei pi wrote:
Currently if hitting block req error, block layer only prints error
log with a rate limitation. Then agent has to parse kernel log to
record what happens.

In this patch, add read/write/discard/flush stat counter to record
io errors.

Signed-off-by: zhenwei pi <pizhenwei@xxxxxxxxxxxxx>
---
block/blk-core.c | 14 +++++++++++---
block/genhd.c | 19 +++++++++++++++++++
include/linux/part_stat.h | 1 +
3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 10c08ac50697..8f1424835700 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1558,9 +1558,17 @@ bool blk_update_request(struct request *req, blk_status_t error,
req->q->integrity.profile->complete_fn(req, nr_bytes);
#endif
- if (unlikely(error && !blk_rq_is_passthrough(req) &&
- !(req->rq_flags & RQF_QUIET)))
- print_req_error(req, error, __func__);
+ if (unlikely(error && !blk_rq_is_passthrough(req))) {
+ if (op_is_flush(req_op(req)))
+ part_stat_inc(&req->rq_disk->part0,
+ io_errors[STAT_FLUSH]);
+ else
+ part_stat_inc(&req->rq_disk->part0,
+ io_errors[op_stat_group(req_op(req))]);
+
+ if (!(req->rq_flags & RQF_QUIET))
+ print_req_error(req, error, __func__);
+ }
blk_account_io_completion(req, nr_bytes);
diff --git a/block/genhd.c b/block/genhd.c
index 99c64641c314..852035095485 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -104,6 +104,7 @@ static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat)
stat->sectors[group] += ptr->sectors[group];
stat->ios[group] += ptr->ios[group];
stat->merges[group] += ptr->merges[group];
+ stat->io_errors[group] += ptr->io_errors[group];
}
stat->io_ticks += ptr->io_ticks;
@@ -1374,6 +1375,22 @@ static ssize_t disk_discard_alignment_show(struct device *dev,
return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
}
+static ssize_t io_error_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct hd_struct *p = dev_to_part(dev);
+ struct disk_stats stat;
+
+ part_stat_read_all(p, &stat);
+
+ return sprintf(buf,
+ "%8lu %8lu %8lu %8lu\n",
+ stat.io_errors[STAT_READ],
+ stat.io_errors[STAT_WRITE],
+ stat.io_errors[STAT_DISCARD],
+ stat.io_errors[STAT_FLUSH]);
+}
+
static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
@@ -1386,6 +1403,7 @@ static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
+static DEVICE_ATTR(io_error, 0444, io_error_show, NULL);
#ifdef CONFIG_FAIL_MAKE_REQUEST
ssize_t part_fail_show(struct device *dev,
@@ -1437,6 +1455,7 @@ static struct attribute *disk_attrs[] = {
#ifdef CONFIG_FAIL_IO_TIMEOUT
&dev_attr_fail_timeout.attr,
#endif
+ &dev_attr_io_error.attr,
NULL
};
diff --git a/include/linux/part_stat.h b/include/linux/part_stat.h
index 24125778ef3e..4fe3836d2308 100644
--- a/include/linux/part_stat.h
+++ b/include/linux/part_stat.h
@@ -9,6 +9,7 @@ struct disk_stats {
unsigned long sectors[NR_STAT_GROUPS];
unsigned long ios[NR_STAT_GROUPS];
unsigned long merges[NR_STAT_GROUPS];
+ unsigned long io_errors[NR_STAT_GROUPS];
unsigned long io_ticks;
local_t in_flight[2];
};


--
zhenwei pi