md/raid5: add blktrace calls
This makes it easier to trace what raid5 is doing.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2cf23f2..ffebc1e 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -53,6 +53,8 @@
#include <linux/cpu.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
+#include <trace/events/block.h>
+
#include "md.h"
#include "raid5.h"
#include "raid0.h"
@@ -182,6 +184,8 @@
return_bi = bi->bi_next;
bi->bi_next = NULL;
bi->bi_size = 0;
+ trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
+ bi, 0);
bio_endio(bi, 0);
bi = return_bi;
}
@@ -671,6 +675,9 @@
bi->bi_next = NULL;
if (rrdev)
set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
+ trace_block_bio_remap(bdev_get_queue(bi->bi_bdev),
+ bi, disk_devt(conf->mddev->gendisk),
+ sh->dev[i].sector);
generic_make_request(bi);
}
if (rrdev) {
@@ -698,6 +705,9 @@
rbi->bi_io_vec[0].bv_offset = 0;
rbi->bi_size = STRIPE_SIZE;
rbi->bi_next = NULL;
+ trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev),
+ rbi, disk_devt(conf->mddev->gendisk),
+ sh->dev[i].sector);
generic_make_request(rbi);
}
if (!rdev && !rrdev) {
@@ -2855,8 +2865,10 @@
pr_debug("for sector %llu, rmw=%d rcw=%d\n",
(unsigned long long)sh->sector, rmw, rcw);
set_bit(STRIPE_HANDLE, &sh->state);
- if (rmw < rcw && rmw > 0)
+ if (rmw < rcw && rmw > 0) {
/* prefer read-modify-write, but need to get some data */
+ blk_add_trace_msg(conf->mddev->queue, "raid5 rmw %llu %d",
+ (unsigned long long)sh->sector, rmw);
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
if ((dev->towrite || i == sh->pd_idx) &&
@@ -2867,7 +2879,7 @@
if (
test_bit(STRIPE_PREREAD_ACTIVE, &sh->state)) {
pr_debug("Read_old block "
- "%d for r-m-w\n", i);
+ "%d for r-m-w\n", i);
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantread, &dev->flags);
s->locked++;
@@ -2877,8 +2889,10 @@
}
}
}
+ }
if (rcw <= rmw && rcw > 0) {
/* want reconstruct write, but need to get some data */
+ int qread =0;
rcw = 0;
for (i = disks; i--; ) {
struct r5dev *dev = &sh->dev[i];
@@ -2897,12 +2911,17 @@
set_bit(R5_LOCKED, &dev->flags);
set_bit(R5_Wantread, &dev->flags);
s->locked++;
+ qread++;
} else {
set_bit(STRIPE_DELAYED, &sh->state);
set_bit(STRIPE_HANDLE, &sh->state);
}
}
}
+ if (rcw)
+ blk_add_trace_msg(conf->mddev->queue, "raid5 rcw %llu %d %d %d",
+ (unsigned long long)sh->sector,
+ rcw, qread, test_bit(STRIPE_DELAYED, &sh->state));
}
/* now if nothing is locked, and if we have enough data,
* we can start a write request
@@ -3900,6 +3919,8 @@
rdev_dec_pending(rdev, conf->mddev);
if (!error && uptodate) {
+ trace_block_bio_complete(bdev_get_queue(raid_bi->bi_bdev),
+ raid_bi, 0);
bio_endio(raid_bi, 0);
if (atomic_dec_and_test(&conf->active_aligned_reads))
wake_up(&conf->wait_for_stripe);
@@ -4004,6 +4025,9 @@
atomic_inc(&conf->active_aligned_reads);
spin_unlock_irq(&conf->device_lock);
+ trace_block_bio_remap(bdev_get_queue(align_bi->bi_bdev),
+ align_bi, disk_devt(mddev->gendisk),
+ raid_bio->bi_sector);
generic_make_request(align_bi);
return 1;
} else {
@@ -4078,6 +4102,7 @@
struct stripe_head *sh;
struct mddev *mddev = cb->cb.data;
struct r5conf *conf = mddev->private;
+ int cnt = 0;
if (cb->list.next && !list_empty(&cb->list)) {
spin_lock_irq(&conf->device_lock);
@@ -4092,9 +4117,11 @@
smp_mb__before_clear_bit();
clear_bit(STRIPE_ON_UNPLUG_LIST, &sh->state);
__release_stripe(conf, sh);
+ cnt++;
}
spin_unlock_irq(&conf->device_lock);
}
+ trace_block_unplug(mddev->queue, cnt, !from_schedule);
kfree(cb);
}
@@ -4352,6 +4379,8 @@
if ( rw == WRITE )
md_write_end(mddev);
+ trace_block_bio_complete(bdev_get_queue(bi->bi_bdev),
+ bi, 0);
bio_endio(bi, 0);
}
}
@@ -4728,8 +4757,11 @@
handled++;
}
remaining = raid5_dec_bi_active_stripes(raid_bio);
- if (remaining == 0)
+ if (remaining == 0) {
+ trace_block_bio_complete(bdev_get_queue(raid_bio->bi_bdev),
+ raid_bio, 0);
bio_endio(raid_bio, 0);
+ }
if (atomic_dec_and_test(&conf->active_aligned_reads))
wake_up(&conf->wait_for_stripe);
return handled;