diff options
Diffstat (limited to 'drivers/md/raid1.c')
| -rw-r--r-- | drivers/md/raid1.c | 208 |
1 files changed, 179 insertions, 29 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 8db311d..cc3939d 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -41,11 +41,7 @@ #include "bitmap.h" #define DEBUG 0 -#if DEBUG -#define PRINTK(x...) printk(x) -#else -#define PRINTK(x...) -#endif +#define PRINTK(x...) do { if (DEBUG) printk(x); } while (0) /* * Number of guaranteed r1bios in case of extreme VM load: @@ -177,12 +173,6 @@ static void free_r1bio(r1bio_t *r1_bio) { conf_t *conf = r1_bio->mddev->private; - /* - * Wake up any possible resync thread that waits for the device - * to go idle. - */ - allow_barrier(conf); - put_all_bios(conf, r1_bio); mempool_free(r1_bio, conf->r1bio_pool); } @@ -223,6 +213,33 @@ static void reschedule_retry(r1bio_t *r1_bio) * operation and are ready to return a success/failure code to the buffer * cache layer. */ +static void call_bio_endio(r1bio_t *r1_bio) +{ + struct bio *bio = r1_bio->master_bio; + int done; + conf_t *conf = r1_bio->mddev->private; + + if (bio->bi_phys_segments) { + unsigned long flags; + spin_lock_irqsave(&conf->device_lock, flags); + bio->bi_phys_segments--; + done = (bio->bi_phys_segments == 0); + spin_unlock_irqrestore(&conf->device_lock, flags); + } else + done = 1; + + if (!test_bit(R1BIO_Uptodate, &r1_bio->state)) + clear_bit(BIO_UPTODATE, &bio->bi_flags); + if (done) { + bio_endio(bio, 0); + /* + * Wake up any possible resync thread that waits for the device + * to go idle. + */ + allow_barrier(conf); + } +} + static void raid_end_bio_io(r1bio_t *r1_bio) { struct bio *bio = r1_bio->master_bio; @@ -235,8 +252,7 @@ static void raid_end_bio_io(r1bio_t *r1_bio) (unsigned long long) bio->bi_sector + (bio->bi_size >> 9) - 1); - bio_endio(bio, - test_bit(R1BIO_Uptodate, &r1_bio->state) ? 0 : -EIO); + call_bio_endio(r1_bio); } free_r1bio(r1_bio); } @@ -295,6 +311,7 @@ static void raid1_end_read_request(struct bio *bio, int error) bdevname(conf->mirrors[mirror].rdev->bdev, b), (unsigned long long)r1_bio->sector); + set_bit(R1BIO_ReadError, &r1_bio->state); reschedule_retry(r1_bio); } @@ -381,7 +398,7 @@ static void raid1_end_write_request(struct bio *bio, int error) (unsigned long long) mbio->bi_sector, (unsigned long long) mbio->bi_sector + (mbio->bi_size >> 9) - 1); - bio_endio(mbio, 0); + call_bio_endio(r1_bio); } } } @@ -412,10 +429,11 @@ static void raid1_end_write_request(struct bio *bio, int error) * * The rdev for the device selected will have nr_pending incremented. */ -static int read_balance(conf_t *conf, r1bio_t *r1_bio) +static int read_balance(conf_t *conf, r1bio_t *r1_bio, int *max_sectors) { const sector_t this_sector = r1_bio->sector; - const int sectors = r1_bio->sectors; + int sectors; + int best_good_sectors; int start_disk; int best_disk; int i; @@ -430,8 +448,11 @@ static int read_balance(conf_t *conf, r1bio_t *r1_bio) * We take the first readable disk when above the resync window. */ retry: + sectors = r1_bio->sectors; best_disk = -1; best_dist = MaxSector; + best_good_sectors = 0; + if (conf->mddev->recovery_cp < MaxSector && (this_sector + sectors >= conf->next_resync)) { choose_first = 1; @@ -443,6 +464,9 @@ static int read_balance(conf_t *conf, r1bio_t *r1_bio) for (i = 0 ; i < conf->raid_disks ; i++) { sector_t dist; + sector_t first_bad; + int bad_sectors; + int disk = start_disk + i; if (disk >= conf->raid_disks) disk -= conf->raid_disks; @@ -465,6 +489,35 @@ static int read_balance(conf_t *conf, r1bio_t *r1_bio) /* This is a reasonable device to use. It might * even be best. */ + if (is_badblock(rdev, this_sector, sectors, + &first_bad, &bad_sectors)) { + if (best_dist < MaxSector) + /* already have a better device */ + continue; + if (first_bad <= this_sector) { + /* cannot read here. If this is the 'primary' + * device, then we must not read beyond + * bad_sectors from another device.. + */ + bad_sectors -= (this_sector - first_bad); + if (choose_first && sectors > bad_sectors) + sectors = bad_sectors; + if (best_good_sectors > sectors) + best_good_sectors = sectors; + + } else { + sector_t good_sectors = first_bad - this_sector; + if (good_sectors > best_good_sectors) { + best_good_sectors = good_sectors; + best_disk = disk; + } + if (choose_first) + break; + } + continue; + } else + best_good_sectors = sectors; + dist = abs(this_sector - conf->mirrors[disk].head_position); if (choose_first /* Don't change to another disk for sequential reads */ @@ -493,10 +546,12 @@ static int read_balance(conf_t *conf, r1bio_t *r1_bio) rdev_dec_pending(rdev, conf->mddev); goto retry; } + sectors = best_good_sectors; conf->next_seq_sect = this_sector + sectors; conf->last_used = best_disk; } rcu_read_unlock(); + *max_sectors = sectors; return best_disk; } @@ -763,11 +818,25 @@ static int make_request(mddev_t *mddev, struct bio * bio) r1_bio->mddev = mddev; r1_bio->sector = bio->bi_sector; + /* We might need to issue multiple reads to different + * devices if there are bad blocks around, so we keep + * track of the number of reads in bio->bi_phys_segments. + * If this is 0, there is only one r1_bio and no locking + * will be needed when requests complete. If it is + * non-zero, then it is the number of not-completed requests. + */ + bio->bi_phys_segments = 0; + clear_bit(BIO_SEG_VALID, &bio->bi_flags); + if (rw == READ) { /* * read balancing logic: */ - int rdisk = read_balance(conf, r1_bio); + int max_sectors; + int rdisk; + +read_again: + rdisk = read_balance(conf, r1_bio, &max_sectors); if (rdisk < 0) { /* couldn't find anywhere to read from */ @@ -788,6 +857,8 @@ static int make_request(mddev_t *mddev, struct bio * bio) r1_bio->read_disk = rdisk; read_bio = bio_clone_mddev(bio, GFP_NOIO, mddev); + md_trim_bio(read_bio, r1_bio->sector - bio->bi_sector, + max_sectors); r1_bio->bios[rdisk] = read_bio; @@ -797,7 +868,38 @@ static int make_request(mddev_t *mddev, struct bio * bio) read_bio->bi_rw = READ | do_sync; read_bio->bi_private = r1_bio; - generic_make_request(read_bio); + if (max_sectors < r1_bio->sectors) { + /* could not read all from this device, so we will + * need another r1_bio. + */ + int sectors_handled; + + sectors_handled = (r1_bio->sector + max_sectors + - bio->bi_sector); + r1_bio->sectors = max_sectors; + spin_lock_irq(&conf->device_lock); + if (bio->bi_phys_segments == 0) + bio->bi_phys_segments = 2; + else + bio->bi_phys_segments++; + spin_unlock_irq(&conf->device_lock); + /* Cannot call generic_make_request directly + * as that will be queued in __make_request + * and subsequent mempool_alloc might block waiting + * for it. So hand bio over to raid1d. + */ + reschedule_retry(r1_bio); + + r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO); + + r1_bio->master_bio = bio; + r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled; + r1_bio->state = 0; + r1_bio->mddev = mddev; + r1_bio->sector = bio->bi_sector + sectors_handled; + goto read_again; + } else + generic_make_request(read_bio); return 0; } @@ -849,8 +951,6 @@ static int make_request(mddev_t *mddev, struct bio * bio) goto retry_write; } - BUG_ON(targets == 0); /* we never fail the last device */ - if (targets < conf->raid_disks) { /* array is degraded, we will not clear the bitmap * on I/O completion (see raid1_end_write_request) */ @@ -1425,7 +1525,7 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio) * * 1. Retries failed read operations on working mirrors. * 2. Updates the raid superblock when problems encounter. - * 3. Performs writes following reads for array syncronising. + * 3. Performs writes following reads for array synchronising. */ static void fix_read_error(conf_t *conf, int read_disk, @@ -1448,9 +1548,14 @@ static void fix_read_error(conf_t *conf, int read_disk, * which is the thread that might remove * a device. If raid1d ever becomes multi-threaded.... */ + sector_t first_bad; + int bad_sectors; + rdev = conf->mirrors[d].rdev; if (rdev && test_bit(In_sync, &rdev->flags) && + is_badblock(rdev, sect, s, + &first_bad, &bad_sectors) == 0 && sync_page_io(rdev, sect, s<<9, conf->tmppage, READ, false)) success = 1; @@ -1546,9 +1651,11 @@ static void raid1d(mddev_t *mddev) conf = mddev->private; if (test_bit(R1BIO_IsSync, &r1_bio->state)) sync_request_write(mddev, r1_bio); - else { + else if (test_bit(R1BIO_ReadError, &r1_bio->state)) { int disk; + int max_sectors; + clear_bit(R1BIO_ReadError, &r1_bio->state); /* we got a read error. Maybe the drive is bad. Maybe just * the block and we can fix it. * We freeze all other IO, and try reading the block from @@ -1568,21 +1675,28 @@ static void raid1d(mddev_t *mddev) conf->mirrors[r1_bio->read_disk].rdev); bio = r1_bio->bios[r1_bio->read_disk]; - if ((disk=read_balance(conf, r1_bio)) == -1) { + bdevname(bio->bi_bdev, b); +read_more: + disk = read_balance(conf, r1_bio, &max_sectors); + if (disk == -1) { printk(KERN_ALERT "md/raid1:%s: %s: unrecoverable I/O" " read error for block %llu\n", - mdname(mddev), - bdevname(bio->bi_bdev,b), + mdname(mddev), b, (unsigned long long)r1_bio->sector); raid_end_bio_io(r1_bio); } else { const unsigned long do_sync = r1_bio->master_bio->bi_rw & REQ_SYNC; - r1_bio->bios[r1_bio->read_disk] = - mddev->ro ? IO_BLOCKED : NULL; + if (bio) { + r1_bio->bios[r1_bio->read_disk] = + mddev->ro ? IO_BLOCKED : NULL; + bio_put(bio); + } r1_bio->read_disk = disk; - bio_put(bio); bio = bio_clone_mddev(r1_bio->master_bio, GFP_NOIO, mddev); + md_trim_bio(bio, + r1_bio->sector - bio->bi_sector, + max_sectors); r1_bio->bios[r1_bio->read_disk] = bio; rdev = conf->mirrors[disk].rdev; printk_ratelimited( @@ -1597,8 +1711,44 @@ static void raid1d(mddev_t *mddev) bio->bi_end_io = raid1_end_read_request; bio->bi_rw = READ | do_sync; bio->bi_private = r1_bio; - generic_make_request(bio); + if (max_sectors < r1_bio->sectors) { + /* Drat - have to split this up more */ + struct bio *mbio = r1_bio->master_bio; + int sectors_handled = + r1_bio->sector + max_sectors + - mbio->bi_sector; + r1_bio->sectors = max_sectors; + spin_lock_irq(&conf->device_lock); + if (mbio->bi_phys_segments == 0) + mbio->bi_phys_segments = 2; + else + mbio->bi_phys_segments++; + spin_unlock_irq(&conf->device_lock); + generic_make_request(bio); + bio = NULL; + + r1_bio = mempool_alloc(conf->r1bio_pool, + GFP_NOIO); + + r1_bio->master_bio = mbio; + r1_bio->sectors = (mbio->bi_size >> 9) + - sectors_handled; + r1_bio->state = 0; + set_bit(R1BIO_ReadError, + &r1_bio->state); + r1_bio->mddev = mddev; + r1_bio->sector = mbio->bi_sector + + sectors_handled; + + goto read_more; + } else + generic_make_request(bio); } + } else { + /* just a partial read to be scheduled from separate + * context + */ + generic_make_request(r1_bio->bios[r1_bio->read_disk]); } cond_resched(); } |