From 4246a0b63bd8f56a1469b12eafeb875b1041a451 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 20 Jul 2015 15:29:37 +0200 Subject: block: add a bi_error field to struct bio Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig Reviewed-by: Hannes Reinecke Reviewed-by: NeilBrown Signed-off-by: Jens Axboe --- drivers/md/raid5.c | 52 ++++++++++++++++++++++++++-------------------------- 1 file changed, 26 insertions(+), 26 deletions(-) (limited to 'drivers/md/raid5.c') diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 59e44e99eef3..84d6eec1033e 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -233,7 +233,7 @@ static void return_io(struct bio *return_bi) bi->bi_iter.bi_size = 0; trace_block_bio_complete(bdev_get_queue(bi->bi_bdev), bi, 0); - bio_endio(bi, 0); + bio_endio(bi); bi = return_bi; } } @@ -887,9 +887,9 @@ static int use_new_offset(struct r5conf *conf, struct stripe_head *sh) } static void -raid5_end_read_request(struct bio *bi, int error); +raid5_end_read_request(struct bio *bi); static void -raid5_end_write_request(struct bio *bi, int error); +raid5_end_write_request(struct bio *bi); static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s) { @@ -2277,12 +2277,11 @@ static void shrink_stripes(struct r5conf *conf) conf->slab_cache = NULL; } -static void raid5_end_read_request(struct bio * bi, int error) +static void raid5_end_read_request(struct bio * bi) { struct stripe_head *sh = bi->bi_private; struct r5conf *conf = sh->raid_conf; int disks = sh->disks, i; - int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); char b[BDEVNAME_SIZE]; struct md_rdev *rdev = NULL; sector_t s; @@ -2291,9 +2290,9 @@ static void raid5_end_read_request(struct bio * bi, int error) if (bi == &sh->dev[i].req) break; - pr_debug("end_read_request %llu/%d, count: %d, uptodate %d.\n", + pr_debug("end_read_request %llu/%d, count: %d, error %d.\n", (unsigned long long)sh->sector, i, atomic_read(&sh->count), - uptodate); + bi->bi_error); if (i == disks) { BUG(); return; @@ -2312,7 +2311,7 @@ static void raid5_end_read_request(struct bio * bi, int error) s = sh->sector + rdev->new_data_offset; else s = sh->sector + rdev->data_offset; - if (uptodate) { + if (!bi->bi_error) { set_bit(R5_UPTODATE, &sh->dev[i].flags); if (test_bit(R5_ReadError, &sh->dev[i].flags)) { /* Note that this cannot happen on a @@ -2400,13 +2399,12 @@ static void raid5_end_read_request(struct bio * bi, int error) release_stripe(sh); } -static void raid5_end_write_request(struct bio *bi, int error) +static void raid5_end_write_request(struct bio *bi) { struct stripe_head *sh = bi->bi_private; struct r5conf *conf = sh->raid_conf; int disks = sh->disks, i; struct md_rdev *uninitialized_var(rdev); - int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); sector_t first_bad; int bad_sectors; int replacement = 0; @@ -2429,23 +2427,23 @@ static void raid5_end_write_request(struct bio *bi, int error) break; } } - pr_debug("end_write_request %llu/%d, count %d, uptodate: %d.\n", + pr_debug("end_write_request %llu/%d, count %d, error: %d.\n", (unsigned long long)sh->sector, i, atomic_read(&sh->count), - uptodate); + bi->bi_error); if (i == disks) { BUG(); return; } if (replacement) { - if (!uptodate) + if (bi->bi_error) md_error(conf->mddev, rdev); else if (is_badblock(rdev, sh->sector, STRIPE_SECTORS, &first_bad, &bad_sectors)) set_bit(R5_MadeGoodRepl, &sh->dev[i].flags); } else { - if (!uptodate) { + if (bi->bi_error) { set_bit(STRIPE_DEGRADED, &sh->state); set_bit(WriteErrorSeen, &rdev->flags); set_bit(R5_WriteError, &sh->dev[i].flags); @@ -2466,7 +2464,7 @@ static void raid5_end_write_request(struct bio *bi, int error) } rdev_dec_pending(rdev, conf->mddev); - if (sh->batch_head && !uptodate && !replacement) + if (sh->batch_head && bi->bi_error && !replacement) set_bit(STRIPE_BATCH_ERR, &sh->batch_head->state); if (!test_and_clear_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags)) @@ -3107,7 +3105,8 @@ handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh, while (bi && bi->bi_iter.bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); - clear_bit(BIO_UPTODATE, &bi->bi_flags); + + bi->bi_error = -EIO; if (!raid5_dec_bi_active_stripes(bi)) { md_write_end(conf->mddev); bi->bi_next = *return_bi; @@ -3131,7 +3130,8 @@ handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh, while (bi && bi->bi_iter.bi_sector < sh->dev[i].sector + STRIPE_SECTORS) { struct bio *bi2 = r5_next_bio(bi, sh->dev[i].sector); - clear_bit(BIO_UPTODATE, &bi->bi_flags); + + bi->bi_error = -EIO; if (!raid5_dec_bi_active_stripes(bi)) { md_write_end(conf->mddev); bi->bi_next = *return_bi; @@ -3156,7 +3156,8 @@ handle_failed_stripe(struct r5conf *conf, struct stripe_head *sh, sh->dev[i].sector + STRIPE_SECTORS) { struct bio *nextbi = r5_next_bio(bi, sh->dev[i].sector); - clear_bit(BIO_UPTODATE, &bi->bi_flags); + + bi->bi_error = -EIO; if (!raid5_dec_bi_active_stripes(bi)) { bi->bi_next = *return_bi; *return_bi = bi; @@ -4749,12 +4750,11 @@ static struct bio *remove_bio_from_retry(struct r5conf *conf) * first). * If the read failed.. */ -static void raid5_align_endio(struct bio *bi, int error) +static void raid5_align_endio(struct bio *bi) { struct bio* raid_bi = bi->bi_private; struct mddev *mddev; struct r5conf *conf; - int uptodate = test_bit(BIO_UPTODATE, &bi->bi_flags); struct md_rdev *rdev; bio_put(bi); @@ -4766,10 +4766,10 @@ static void raid5_align_endio(struct bio *bi, int error) rdev_dec_pending(rdev, conf->mddev); - if (!error && uptodate) { + if (!bi->bi_error) { trace_block_bio_complete(bdev_get_queue(raid_bi->bi_bdev), raid_bi, 0); - bio_endio(raid_bi, 0); + bio_endio(raid_bi); if (atomic_dec_and_test(&conf->active_aligned_reads)) wake_up(&conf->wait_for_quiescent); return; @@ -5133,7 +5133,7 @@ static void make_discard_request(struct mddev *mddev, struct bio *bi) remaining = raid5_dec_bi_active_stripes(bi); if (remaining == 0) { md_write_end(mddev); - bio_endio(bi, 0); + bio_endio(bi); } } @@ -5297,7 +5297,7 @@ static void make_request(struct mddev *mddev, struct bio * bi) release_stripe_plug(mddev, sh); } else { /* cannot get stripe for read-ahead, just give-up */ - clear_bit(BIO_UPTODATE, &bi->bi_flags); + bi->bi_error = -EIO; break; } } @@ -5311,7 +5311,7 @@ static void make_request(struct mddev *mddev, struct bio * bi) trace_block_bio_complete(bdev_get_queue(bi->bi_bdev), bi, 0); - bio_endio(bi, 0); + bio_endio(bi); } } @@ -5707,7 +5707,7 @@ static int retry_aligned_read(struct r5conf *conf, struct bio *raid_bio) if (remaining == 0) { trace_block_bio_complete(bdev_get_queue(raid_bio->bi_bdev), raid_bio, 0); - bio_endio(raid_bio, 0); + bio_endio(raid_bio); } if (atomic_dec_and_test(&conf->active_aligned_reads)) wake_up(&conf->wait_for_quiescent); -- cgit v1.2.1