Commit 109e3765 authored by NeilBrown's avatar NeilBrown Committed by Shaohua Li

md: add block tracing for bio_remapping

The block tracing infrastructure (accessed with blktrace/blkparse)
supports the tracing of mapping bios from one device to another.
This is currently used when a bio in a partition is mapped to the
whole device, when bios are mapped by dm, and for mapping in md/raid5.
Other md personalities do not include this tracing yet, so add it.

When a read-error is detected we redirect the request to a different device.
This could justifiably be seen as a new mapping for the originial bio,
or a secondary mapping for the bio that errors.  This patch uses
the second option.

When md is used under dm-raid, the mappings are not traced as we do
not have access to the block device number of the parent.
Signed-off-by: default avatarNeilBrown <neilb@suse.com>
Signed-off-by: default avatarShaohua Li <shli@fb.com>
parent 354b445b
......@@ -21,6 +21,7 @@
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <trace/events/block.h>
#include "md.h"
#include "linear.h"
......@@ -227,22 +228,22 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio)
}
do {
tmp_dev = which_dev(mddev, bio->bi_iter.bi_sector);
sector_t bio_sector = bio->bi_iter.bi_sector;
tmp_dev = which_dev(mddev, bio_sector);
start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;
end_sector = tmp_dev->end_sector;
data_offset = tmp_dev->rdev->data_offset;
bio->bi_bdev = tmp_dev->rdev->bdev;
if (unlikely(bio->bi_iter.bi_sector >= end_sector ||
bio->bi_iter.bi_sector < start_sector))
if (unlikely(bio_sector >= end_sector ||
bio_sector < start_sector))
goto out_of_bounds;
if (unlikely(bio_end_sector(bio) > end_sector)) {
/* This bio crosses a device boundary, so we have to
* split it.
*/
split = bio_split(bio, end_sector -
bio->bi_iter.bi_sector,
split = bio_split(bio, end_sector - bio_sector,
GFP_NOIO, fs_bio_set);
bio_chain(split, bio);
} else {
......@@ -256,8 +257,13 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio)
!blk_queue_discard(bdev_get_queue(split->bi_bdev)))) {
/* Just ignore it */
bio_endio(split);
} else
} else {
if (mddev->gendisk)
trace_block_bio_remap(bdev_get_queue(split->bi_bdev),
split, disk_devt(mddev->gendisk),
bio_sector);
generic_make_request(split);
}
} while (split != bio);
return;
......
......@@ -21,6 +21,7 @@
#include <linux/seq_file.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <trace/events/block.h>
#include "md.h"
#include "raid0.h"
#include "raid5.h"
......@@ -463,7 +464,8 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
}
do {
sector_t sector = bio->bi_iter.bi_sector;
sector_t bio_sector = bio->bi_iter.bi_sector;
sector_t sector = bio_sector;
unsigned chunk_sects = mddev->chunk_sectors;
unsigned sectors = chunk_sects -
......@@ -472,7 +474,7 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
: sector_div(sector, chunk_sects));
/* Restore due to sector_div */
sector = bio->bi_iter.bi_sector;
sector = bio_sector;
if (sectors < bio_sectors(bio)) {
split = bio_split(bio, sectors, GFP_NOIO, fs_bio_set);
......@@ -491,8 +493,13 @@ static void raid0_make_request(struct mddev *mddev, struct bio *bio)
!blk_queue_discard(bdev_get_queue(split->bi_bdev)))) {
/* Just ignore it */
bio_endio(split);
} else
} else {
if (mddev->gendisk)
trace_block_bio_remap(bdev_get_queue(split->bi_bdev),
split, disk_devt(mddev->gendisk),
bio_sector);
generic_make_request(split);
}
} while (split != bio);
}
......
......@@ -37,6 +37,7 @@
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/ratelimit.h>
#include <trace/events/block.h>
#include "md.h"
#include "raid1.h"
#include "bitmap.h"
......@@ -1162,6 +1163,11 @@ static void raid1_make_request(struct mddev *mddev, struct bio * bio)
bio_set_op_attrs(read_bio, op, do_sync);
read_bio->bi_private = r1_bio;
if (mddev->gendisk)
trace_block_bio_remap(bdev_get_queue(read_bio->bi_bdev),
read_bio, disk_devt(mddev->gendisk),
r1_bio->sector);
if (max_sectors < r1_bio->sectors) {
/* could not read all from this device, so we will
* need another r1_bio.
......@@ -1367,13 +1373,20 @@ static void raid1_make_request(struct mddev *mddev, struct bio * bio)
mbio->bi_iter.bi_sector = (r1_bio->sector +
conf->mirrors[i].rdev->data_offset);
mbio->bi_bdev = (void*)conf->mirrors[i].rdev;
mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
mbio->bi_end_io = raid1_end_write_request;
bio_set_op_attrs(mbio, op, do_flush_fua | do_sync);
mbio->bi_private = r1_bio;
atomic_inc(&r1_bio->remaining);
if (mddev->gendisk)
trace_block_bio_remap(bdev_get_queue(mbio->bi_bdev),
mbio, disk_devt(mddev->gendisk),
r1_bio->sector);
/* flush_pending_writes() needs access to the rdev so...*/
mbio->bi_bdev = (void*)conf->mirrors[i].rdev;
cb = blk_check_plugged(raid1_unplug, mddev, sizeof(*plug));
if (cb)
plug = container_of(cb, struct raid1_plug_cb, cb);
......@@ -2290,6 +2303,8 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
struct bio *bio;
char b[BDEVNAME_SIZE];
struct md_rdev *rdev;
dev_t bio_dev;
sector_t bio_sector;
clear_bit(R1BIO_ReadError, &r1_bio->state);
/* we got a read error. Maybe the drive is bad. Maybe just
......@@ -2303,6 +2318,8 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
bio = r1_bio->bios[r1_bio->read_disk];
bdevname(bio->bi_bdev, b);
bio_dev = bio->bi_bdev->bd_dev;
bio_sector = conf->mirrors[r1_bio->read_disk].rdev->data_offset + r1_bio->sector;
bio_put(bio);
r1_bio->bios[r1_bio->read_disk] = NULL;
......@@ -2353,6 +2370,8 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
else
mbio->bi_phys_segments++;
spin_unlock_irq(&conf->device_lock);
trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
bio, bio_dev, bio_sector);
generic_make_request(bio);
bio = NULL;
......@@ -2367,9 +2386,12 @@ static void handle_read_error(struct r1conf *conf, struct r1bio *r1_bio)
sectors_handled;
goto read_more;
} else
} else {
trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
bio, bio_dev, bio_sector);
generic_make_request(bio);
}
}
}
static void raid1d(struct md_thread *thread)
......
......@@ -25,6 +25,7 @@
#include <linux/seq_file.h>
#include <linux/ratelimit.h>
#include <linux/kthread.h>
#include <trace/events/block.h>
#include "md.h"
#include "raid10.h"
#include "raid0.h"
......@@ -1165,6 +1166,10 @@ static void __make_request(struct mddev *mddev, struct bio *bio)
bio_set_op_attrs(read_bio, op, do_sync);
read_bio->bi_private = r10_bio;
if (mddev->gendisk)
trace_block_bio_remap(bdev_get_queue(read_bio->bi_bdev),
read_bio, disk_devt(mddev->gendisk),
r10_bio->sector);
if (max_sectors < r10_bio->sectors) {
/* Could not read all from this device, so we will
* need another r10_bio.
......@@ -1367,11 +1372,18 @@ static void __make_request(struct mddev *mddev, struct bio *bio)
mbio->bi_iter.bi_sector = (r10_bio->devs[i].addr+
choose_data_offset(r10_bio,
rdev));
mbio->bi_bdev = (void*)rdev;
mbio->bi_bdev = rdev->bdev;
mbio->bi_end_io = raid10_end_write_request;
bio_set_op_attrs(mbio, op, do_sync | do_fua);
mbio->bi_private = r10_bio;
if (conf->mddev->gendisk)
trace_block_bio_remap(bdev_get_queue(mbio->bi_bdev),
mbio, disk_devt(conf->mddev->gendisk),
r10_bio->sector);
/* flush_pending_writes() needs access to the rdev so...*/
mbio->bi_bdev = (void*)rdev;
atomic_inc(&r10_bio->remaining);
cb = blk_check_plugged(raid10_unplug, mddev,
......@@ -1409,11 +1421,18 @@ static void __make_request(struct mddev *mddev, struct bio *bio)
mbio->bi_iter.bi_sector = (r10_bio->devs[i].addr +
choose_data_offset(
r10_bio, rdev));
mbio->bi_bdev = (void*)rdev;
mbio->bi_bdev = rdev->bdev;
mbio->bi_end_io = raid10_end_write_request;
bio_set_op_attrs(mbio, op, do_sync | do_fua);
mbio->bi_private = r10_bio;
if (conf->mddev->gendisk)
trace_block_bio_remap(bdev_get_queue(mbio->bi_bdev),
mbio, disk_devt(conf->mddev->gendisk),
r10_bio->sector);
/* flush_pending_writes() needs access to the rdev so...*/
mbio->bi_bdev = (void*)rdev;
atomic_inc(&r10_bio->remaining);
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
......@@ -2496,6 +2515,8 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
char b[BDEVNAME_SIZE];
unsigned long do_sync;
int max_sectors;
dev_t bio_dev;
sector_t bio_last_sector;
/* we got a read error. Maybe the drive is bad. Maybe just
* the block and we can fix it.
......@@ -2507,6 +2528,8 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
*/
bio = r10_bio->devs[slot].bio;
bdevname(bio->bi_bdev, b);
bio_dev = bio->bi_bdev->bd_dev;
bio_last_sector = r10_bio->devs[slot].addr + rdev->data_offset + r10_bio->sectors;
bio_put(bio);
r10_bio->devs[slot].bio = NULL;
......@@ -2546,6 +2569,10 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
bio_set_op_attrs(bio, REQ_OP_READ, do_sync);
bio->bi_private = r10_bio;
bio->bi_end_io = raid10_end_read_request;
trace_block_bio_remap(bdev_get_queue(bio->bi_bdev),
bio, bio_dev,
bio_last_sector - r10_bio->sectors);
if (max_sectors < r10_bio->sectors) {
/* Drat - have to split this up more */
struct bio *mbio = r10_bio->master_bio;
......
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