mirror of
https://github.com/torvalds/linux.git
synced 2024-11-26 22:21:42 +00:00
md/raid10: simplify handle_read_error()
handle_read_error() duplicates a lot of the work that raid10_read_request() does, so it makes sense to just use that function. handle_read_error() relies on the same r10bio being re-used so that, in the case of a read-only array, setting IO_BLOCKED in r1bio->devs[].bio ensures read_balance() won't re-use that device. So when called from raid10_make_request() we clear that array, but not when called from handle_read_error(). Two parts of handle_read_error() that need to be preserved are the warning message it prints, so they are conditionally added to raid10_read_request(). If the failing rdev can be found, messages are printed. Otherwise they aren't. Not that as rdev_dec_pending() has already been called on the failing rdev, we need to use rcu_read_lock() to get a new reference from the conf. We only use this to get the name of the failing block device. With this change, we no longer need inc_pending(). Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
This commit is contained in:
NeilBrown
Shaohua Li
parent
fc9977dd06
commit
545250f248
@ -1008,15 +1008,6 @@ static void wait_barrier(struct r10conf *conf)
|
||||
spin_unlock_irq(&conf->resync_lock);
|
||||
}
|
||||
|
||||
static void inc_pending(struct r10conf *conf)
|
||||
{
|
||||
/* The current request requires multiple r10_bio, so
|
||||
* we need to increment the pending count.
|
||||
*/
|
||||
WARN_ON(!atomic_read(&conf->nr_pending));
|
||||
atomic_inc(&conf->nr_pending);
|
||||
}
|
||||
|
||||
static void allow_barrier(struct r10conf *conf)
|
||||
{
|
||||
if ((atomic_dec_and_test(&conf->nr_pending)) ||
|
||||
@ -1130,8 +1121,38 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
|
||||
int max_sectors;
|
||||
sector_t sectors;
|
||||
struct md_rdev *rdev;
|
||||
int slot;
|
||||
char b[BDEVNAME_SIZE];
|
||||
int slot = r10_bio->read_slot;
|
||||
struct md_rdev *err_rdev = NULL;
|
||||
gfp_t gfp = GFP_NOIO;
|
||||
|
||||
if (r10_bio->devs[slot].rdev) {
|
||||
/*
|
||||
* This is an error retry, but we cannot
|
||||
* safely dereference the rdev in the r10_bio,
|
||||
* we must use the one in conf.
|
||||
* If it has already been disconnected (unlikely)
|
||||
* we lose the device name in error messages.
|
||||
*/
|
||||
int disk;
|
||||
/*
|
||||
* As we are blocking raid10, it is a little safer to
|
||||
* use __GFP_HIGH.
|
||||
*/
|
||||
gfp = GFP_NOIO | __GFP_HIGH;
|
||||
|
||||
rcu_read_lock();
|
||||
disk = r10_bio->devs[slot].devnum;
|
||||
err_rdev = rcu_dereference(conf->mirrors[disk].rdev);
|
||||
if (err_rdev)
|
||||
bdevname(err_rdev->bdev, b);
|
||||
else {
|
||||
strcpy(b, "???");
|
||||
/* This never gets dereferenced */
|
||||
err_rdev = r10_bio->devs[slot].rdev;
|
||||
}
|
||||
rcu_read_unlock();
|
||||
}
|
||||
/*
|
||||
* Register the new request and wait if the reconstruction
|
||||
* thread has put up a bar for new requests.
|
||||
@ -1158,12 +1179,22 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
|
||||
|
||||
rdev = read_balance(conf, r10_bio, &max_sectors);
|
||||
if (!rdev) {
|
||||
if (err_rdev) {
|
||||
pr_crit_ratelimited("md/raid10:%s: %s: unrecoverable I/O read error for block %llu\n",
|
||||
mdname(mddev), b,
|
||||
(unsigned long long)r10_bio->sector);
|
||||
}
|
||||
raid_end_bio_io(r10_bio);
|
||||
return;
|
||||
}
|
||||
if (err_rdev)
|
||||
pr_err_ratelimited("md/raid10:%s: %s: redirecting sector %llu to another mirror\n",
|
||||
mdname(mddev),
|
||||
bdevname(rdev->bdev, b),
|
||||
(unsigned long long)r10_bio->sector);
|
||||
if (max_sectors < bio_sectors(bio)) {
|
||||
struct bio *split = bio_split(bio, max_sectors,
|
||||
GFP_NOIO, conf->bio_split);
|
||||
gfp, conf->bio_split);
|
||||
bio_chain(split, bio);
|
||||
generic_make_request(bio);
|
||||
bio = split;
|
||||
@ -1172,7 +1203,7 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
|
||||
}
|
||||
slot = r10_bio->read_slot;
|
||||
|
||||
read_bio = bio_clone_fast(bio, GFP_NOIO, mddev->bio_set);
|
||||
read_bio = bio_clone_fast(bio, gfp, mddev->bio_set);
|
||||
|
||||
r10_bio->devs[slot].bio = read_bio;
|
||||
r10_bio->devs[slot].rdev = rdev;
|
||||
@ -1487,6 +1518,7 @@ static void __make_request(struct mddev *mddev, struct bio *bio, int sectors)
|
||||
r10_bio->mddev = mddev;
|
||||
r10_bio->sector = bio->bi_iter.bi_sector;
|
||||
r10_bio->state = 0;
|
||||
memset(r10_bio->devs, 0, sizeof(r10_bio->devs[0]) * conf->copies);
|
||||
|
||||
if (bio_data_dir(bio) == READ)
|
||||
raid10_read_request(mddev, bio, r10_bio);
|
||||
@ -2556,9 +2588,6 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
|
||||
struct bio *bio;
|
||||
struct r10conf *conf = mddev->private;
|
||||
struct md_rdev *rdev = r10_bio->devs[slot].rdev;
|
||||
char b[BDEVNAME_SIZE];
|
||||
unsigned long do_sync;
|
||||
int max_sectors;
|
||||
dev_t bio_dev;
|
||||
sector_t bio_last_sector;
|
||||
|
||||
@ -2571,7 +2600,6 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
|
||||
* frozen.
|
||||
*/
|
||||
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);
|
||||
@ -2587,65 +2615,9 @@ static void handle_read_error(struct mddev *mddev, struct r10bio *r10_bio)
|
||||
md_error(mddev, rdev);
|
||||
|
||||
rdev_dec_pending(rdev, mddev);
|
||||
|
||||
read_more:
|
||||
rdev = read_balance(conf, r10_bio, &max_sectors);
|
||||
if (rdev == NULL) {
|
||||
pr_crit_ratelimited("md/raid10:%s: %s: unrecoverable I/O read error for block %llu\n",
|
||||
mdname(mddev), b,
|
||||
(unsigned long long)r10_bio->sector);
|
||||
raid_end_bio_io(r10_bio);
|
||||
return;
|
||||
}
|
||||
|
||||
do_sync = (r10_bio->master_bio->bi_opf & REQ_SYNC);
|
||||
slot = r10_bio->read_slot;
|
||||
pr_err_ratelimited("md/raid10:%s: %s: redirecting sector %llu to another mirror\n",
|
||||
mdname(mddev),
|
||||
bdevname(rdev->bdev, b),
|
||||
(unsigned long long)r10_bio->sector);
|
||||
bio = bio_clone_fast(r10_bio->master_bio, GFP_NOIO, mddev->bio_set);
|
||||
bio_trim(bio, r10_bio->sector - bio->bi_iter.bi_sector, max_sectors);
|
||||
r10_bio->devs[slot].bio = bio;
|
||||
r10_bio->devs[slot].rdev = rdev;
|
||||
bio->bi_iter.bi_sector = r10_bio->devs[slot].addr
|
||||
+ choose_data_offset(r10_bio, rdev);
|
||||
bio->bi_bdev = rdev->bdev;
|
||||
bio_set_op_attrs(bio, REQ_OP_READ, do_sync);
|
||||
if (test_bit(FailFast, &rdev->flags) &&
|
||||
test_bit(R10BIO_FailFast, &r10_bio->state))
|
||||
bio->bi_opf |= MD_FAILFAST;
|
||||
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;
|
||||
int sectors_handled =
|
||||
r10_bio->sector + max_sectors
|
||||
- mbio->bi_iter.bi_sector;
|
||||
r10_bio->sectors = max_sectors;
|
||||
bio_inc_remaining(mbio);
|
||||
inc_pending(conf);
|
||||
generic_make_request(bio);
|
||||
|
||||
r10_bio = mempool_alloc(conf->r10bio_pool,
|
||||
GFP_NOIO);
|
||||
r10_bio->master_bio = mbio;
|
||||
r10_bio->sectors = bio_sectors(mbio) - sectors_handled;
|
||||
r10_bio->state = 0;
|
||||
set_bit(R10BIO_ReadError,
|
||||
&r10_bio->state);
|
||||
r10_bio->mddev = mddev;
|
||||
r10_bio->sector = mbio->bi_iter.bi_sector
|
||||
+ sectors_handled;
|
||||
|
||||
goto read_more;
|
||||
} else
|
||||
generic_make_request(bio);
|
||||
allow_barrier(conf);
|
||||
r10_bio->state = 0;
|
||||
raid10_read_request(mddev, r10_bio->master_bio, r10_bio);
|
||||
}
|
||||
|
||||
static void handle_write_completed(struct r10conf *conf, struct r10bio *r10_bio)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user