[PATCH] md: tidyup some issues with raid1 resync and prepare for catching read errors
We are dereferencing ->rdev without an rcu lock! Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
NeilBrown
Linus Torvalds
parent
ddaf22abaa
commit
3e198f7826
1 changed files with 57 additions and 55 deletions
|
|
@ -177,6 +177,13 @@ static inline void free_r1bio(r1bio_t *r1_bio)
|
|||
static inline void put_buf(r1bio_t *r1_bio)
|
||||
{
|
||||
conf_t *conf = mddev_to_conf(r1_bio->mddev);
|
||||
int i;
|
||||
|
||||
for (i=0; i<conf->raid_disks; i++) {
|
||||
struct bio *bio = r1_bio->bios[i];
|
||||
if (bio->bi_end_io)
|
||||
rdev_dec_pending(conf->mirrors[i].rdev, r1_bio->mddev);
|
||||
}
|
||||
|
||||
mempool_free(r1_bio, conf->r1buf_pool);
|
||||
|
||||
|
|
@ -1085,7 +1092,6 @@ static int end_sync_read(struct bio *bio, unsigned int bytes_done, int error)
|
|||
conf->mirrors[r1_bio->read_disk].rdev);
|
||||
} else
|
||||
set_bit(R1BIO_Uptodate, &r1_bio->state);
|
||||
rdev_dec_pending(conf->mirrors[r1_bio->read_disk].rdev, conf->mddev);
|
||||
reschedule_retry(r1_bio);
|
||||
return 0;
|
||||
}
|
||||
|
|
@ -1116,7 +1122,6 @@ static int end_sync_write(struct bio *bio, unsigned int bytes_done, int error)
|
|||
md_done_sync(mddev, r1_bio->sectors, uptodate);
|
||||
put_buf(r1_bio);
|
||||
}
|
||||
rdev_dec_pending(conf->mirrors[mirror].rdev, mddev);
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
@ -1153,10 +1158,14 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
|
|||
atomic_set(&r1_bio->remaining, 1);
|
||||
for (i = 0; i < disks ; i++) {
|
||||
wbio = r1_bio->bios[i];
|
||||
if (wbio->bi_end_io != end_sync_write)
|
||||
if (wbio->bi_end_io == NULL ||
|
||||
(wbio->bi_end_io == end_sync_read &&
|
||||
(i == r1_bio->read_disk ||
|
||||
!test_bit(MD_RECOVERY_SYNC, &mddev->recovery))))
|
||||
continue;
|
||||
|
||||
atomic_inc(&conf->mirrors[i].rdev->nr_pending);
|
||||
wbio->bi_rw = WRITE;
|
||||
wbio->bi_end_io = end_sync_write;
|
||||
atomic_inc(&r1_bio->remaining);
|
||||
md_sync_acct(conf->mirrors[i].rdev->bdev, wbio->bi_size >> 9);
|
||||
|
||||
|
|
@ -1388,14 +1397,13 @@ static int init_resync(conf_t *conf)
|
|||
static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, int go_faster)
|
||||
{
|
||||
conf_t *conf = mddev_to_conf(mddev);
|
||||
mirror_info_t *mirror;
|
||||
r1bio_t *r1_bio;
|
||||
struct bio *bio;
|
||||
sector_t max_sector, nr_sectors;
|
||||
int disk;
|
||||
int disk = -1;
|
||||
int i;
|
||||
int wonly;
|
||||
int write_targets = 0;
|
||||
int wonly = -1;
|
||||
int write_targets = 0, read_targets = 0;
|
||||
int sync_blocks;
|
||||
int still_degraded = 0;
|
||||
|
||||
|
|
@ -1447,44 +1455,24 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
|
|||
|
||||
conf->next_resync = sector_nr;
|
||||
|
||||
/*
|
||||
* If reconstructing, and >1 working disc,
|
||||
* could dedicate one to rebuild and others to
|
||||
* service read requests ..
|
||||
*/
|
||||
disk = conf->last_used;
|
||||
/* make sure disk is operational */
|
||||
wonly = disk;
|
||||
while (conf->mirrors[disk].rdev == NULL ||
|
||||
!test_bit(In_sync, &conf->mirrors[disk].rdev->flags) ||
|
||||
test_bit(WriteMostly, &conf->mirrors[disk].rdev->flags)
|
||||
) {
|
||||
if (conf->mirrors[disk].rdev &&
|
||||
test_bit(In_sync, &conf->mirrors[disk].rdev->flags))
|
||||
wonly = disk;
|
||||
if (disk <= 0)
|
||||
disk = conf->raid_disks;
|
||||
disk--;
|
||||
if (disk == conf->last_used) {
|
||||
disk = wonly;
|
||||
break;
|
||||
}
|
||||
}
|
||||
conf->last_used = disk;
|
||||
atomic_inc(&conf->mirrors[disk].rdev->nr_pending);
|
||||
|
||||
|
||||
mirror = conf->mirrors + disk;
|
||||
|
||||
r1_bio = mempool_alloc(conf->r1buf_pool, GFP_NOIO);
|
||||
rcu_read_lock();
|
||||
/*
|
||||
* If we get a correctably read error during resync or recovery,
|
||||
* we might want to read from a different device. So we
|
||||
* flag all drives that could conceivably be read from for READ,
|
||||
* and any others (which will be non-In_sync devices) for WRITE.
|
||||
* If a read fails, we try reading from something else for which READ
|
||||
* is OK.
|
||||
*/
|
||||
|
||||
r1_bio->mddev = mddev;
|
||||
r1_bio->sector = sector_nr;
|
||||
r1_bio->state = 0;
|
||||
set_bit(R1BIO_IsSync, &r1_bio->state);
|
||||
r1_bio->read_disk = disk;
|
||||
|
||||
for (i=0; i < conf->raid_disks; i++) {
|
||||
mdk_rdev_t *rdev;
|
||||
bio = r1_bio->bios[i];
|
||||
|
||||
/* take from bio_init */
|
||||
|
|
@ -1499,35 +1487,49 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
|
|||
bio->bi_end_io = NULL;
|
||||
bio->bi_private = NULL;
|
||||
|
||||
if (i == disk) {
|
||||
bio->bi_rw = READ;
|
||||
bio->bi_end_io = end_sync_read;
|
||||
} else if (conf->mirrors[i].rdev == NULL ||
|
||||
test_bit(Faulty, &conf->mirrors[i].rdev->flags)) {
|
||||
rdev = rcu_dereference(conf->mirrors[i].rdev);
|
||||
if (rdev == NULL ||
|
||||
test_bit(Faulty, &rdev->flags)) {
|
||||
still_degraded = 1;
|
||||
continue;
|
||||
} else if (!test_bit(In_sync, &conf->mirrors[i].rdev->flags) ||
|
||||
sector_nr + RESYNC_SECTORS > mddev->recovery_cp ||
|
||||
test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
|
||||
} else if (!test_bit(In_sync, &rdev->flags)) {
|
||||
bio->bi_rw = WRITE;
|
||||
bio->bi_end_io = end_sync_write;
|
||||
write_targets ++;
|
||||
} else
|
||||
/* no need to read or write here */
|
||||
continue;
|
||||
bio->bi_sector = sector_nr + conf->mirrors[i].rdev->data_offset;
|
||||
bio->bi_bdev = conf->mirrors[i].rdev->bdev;
|
||||
} else {
|
||||
/* may need to read from here */
|
||||
bio->bi_rw = READ;
|
||||
bio->bi_end_io = end_sync_read;
|
||||
if (test_bit(WriteMostly, &rdev->flags)) {
|
||||
if (wonly < 0)
|
||||
wonly = i;
|
||||
} else {
|
||||
if (disk < 0)
|
||||
disk = i;
|
||||
}
|
||||
read_targets++;
|
||||
}
|
||||
atomic_inc(&rdev->nr_pending);
|
||||
bio->bi_sector = sector_nr + rdev->data_offset;
|
||||
bio->bi_bdev = rdev->bdev;
|
||||
bio->bi_private = r1_bio;
|
||||
}
|
||||
rcu_read_unlock();
|
||||
if (disk < 0)
|
||||
disk = wonly;
|
||||
r1_bio->read_disk = disk;
|
||||
|
||||
if (write_targets == 0) {
|
||||
if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery) && read_targets > 0)
|
||||
/* extra read targets are also write targets */
|
||||
write_targets += read_targets-1;
|
||||
|
||||
if (write_targets == 0 || read_targets == 0) {
|
||||
/* There is nowhere to write, so all non-sync
|
||||
* drives must be failed - so we are finished
|
||||
*/
|
||||
sector_t rv = max_sector - sector_nr;
|
||||
*skipped = 1;
|
||||
put_buf(r1_bio);
|
||||
rdev_dec_pending(conf->mirrors[disk].rdev, mddev);
|
||||
return rv;
|
||||
}
|
||||
|
||||
|
|
@ -1578,10 +1580,10 @@ static sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *skipped, i
|
|||
sync_blocks -= (len>>9);
|
||||
} while (r1_bio->bios[disk]->bi_vcnt < RESYNC_PAGES);
|
||||
bio_full:
|
||||
bio = r1_bio->bios[disk];
|
||||
bio = r1_bio->bios[r1_bio->read_disk];
|
||||
r1_bio->sectors = nr_sectors;
|
||||
|
||||
md_sync_acct(mirror->rdev->bdev, nr_sectors);
|
||||
md_sync_acct(conf->mirrors[r1_bio->read_disk].rdev->bdev, nr_sectors);
|
||||
|
||||
generic_make_request(bio);
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue