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md/raid10: pull codes that wait for blocked dev into one function
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The following patch will reuse these logics, so pull the same codes into
one function.

Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
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Xiao Ni authored and Song Liu committed Sep 24, 2020
1 parent 8650a88 commit f046f5d
Showing 1 changed file with 67 additions and 51 deletions.
118 changes: 67 additions & 51 deletions drivers/md/raid10.c
Original file line number Diff line number Diff line change
Expand Up @@ -1275,12 +1275,75 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
}
}

static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio)
{
int i;
struct r10conf *conf = mddev->private;
struct md_rdev *blocked_rdev;

retry_wait:
blocked_rdev = NULL;
rcu_read_lock();
for (i = 0; i < conf->copies; i++) {
struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
struct md_rdev *rrdev = rcu_dereference(
conf->mirrors[i].replacement);
if (rdev == rrdev)
rrdev = NULL;
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
atomic_inc(&rdev->nr_pending);
blocked_rdev = rdev;
break;
}
if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
atomic_inc(&rrdev->nr_pending);
blocked_rdev = rrdev;
break;
}

if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t first_bad;
sector_t dev_sector = r10_bio->devs[i].addr;
int bad_sectors;
int is_bad;

/* Discard request doesn't care the write result
* so it doesn't need to wait blocked disk here.
*/
if (!r10_bio->sectors)
continue;

is_bad = is_badblock(rdev, dev_sector, r10_bio->sectors,
&first_bad, &bad_sectors);
if (is_bad < 0) {
/* Mustn't write here until the bad block
* is acknowledged
*/
atomic_inc(&rdev->nr_pending);
set_bit(BlockedBadBlocks, &rdev->flags);
blocked_rdev = rdev;
break;
}
}
}
rcu_read_unlock();

if (unlikely(blocked_rdev)) {
/* Have to wait for this device to get unblocked, then retry */
allow_barrier(conf);
raid10_log(conf->mddev, "%s wait rdev %d blocked",
__func__, blocked_rdev->raid_disk);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
wait_barrier(conf);
goto retry_wait;
}
}

static void raid10_write_request(struct mddev *mddev, struct bio *bio,
struct r10bio *r10_bio)
{
struct r10conf *conf = mddev->private;
int i;
struct md_rdev *blocked_rdev;
sector_t sectors;
int max_sectors;

Expand Down Expand Up @@ -1338,8 +1401,9 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,

r10_bio->read_slot = -1; /* make sure repl_bio gets freed */
raid10_find_phys(conf, r10_bio);
retry_write:
blocked_rdev = NULL;

wait_blocked_dev(mddev, r10_bio);

rcu_read_lock();
max_sectors = r10_bio->sectors;

Expand All @@ -1350,16 +1414,6 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
conf->mirrors[d].replacement);
if (rdev == rrdev)
rrdev = NULL;
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
atomic_inc(&rdev->nr_pending);
blocked_rdev = rdev;
break;
}
if (rrdev && unlikely(test_bit(Blocked, &rrdev->flags))) {
atomic_inc(&rrdev->nr_pending);
blocked_rdev = rrdev;
break;
}
if (rdev && (test_bit(Faulty, &rdev->flags)))
rdev = NULL;
if (rrdev && (test_bit(Faulty, &rrdev->flags)))
Expand All @@ -1380,15 +1434,6 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,

is_bad = is_badblock(rdev, dev_sector, max_sectors,
&first_bad, &bad_sectors);
if (is_bad < 0) {
/* Mustn't write here until the bad block
* is acknowledged
*/
atomic_inc(&rdev->nr_pending);
set_bit(BlockedBadBlocks, &rdev->flags);
blocked_rdev = rdev;
break;
}
if (is_bad && first_bad <= dev_sector) {
/* Cannot write here at all */
bad_sectors -= (dev_sector - first_bad);
Expand Down Expand Up @@ -1424,35 +1469,6 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
}
rcu_read_unlock();

if (unlikely(blocked_rdev)) {
/* Have to wait for this device to get unblocked, then retry */
int j;
int d;

for (j = 0; j < i; j++) {
if (r10_bio->devs[j].bio) {
d = r10_bio->devs[j].devnum;
rdev_dec_pending(conf->mirrors[d].rdev, mddev);
}
if (r10_bio->devs[j].repl_bio) {
struct md_rdev *rdev;
d = r10_bio->devs[j].devnum;
rdev = conf->mirrors[d].replacement;
if (!rdev) {
/* Race with remove_disk */
smp_mb();
rdev = conf->mirrors[d].rdev;
}
rdev_dec_pending(rdev, mddev);
}
}
allow_barrier(conf);
raid10_log(conf->mddev, "wait rdev %d blocked", blocked_rdev->raid_disk);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
wait_barrier(conf);
goto retry_write;
}

if (max_sectors < r10_bio->sectors)
r10_bio->sectors = max_sectors;

Expand Down

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