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 --- fs/btrfs/raid56.c | 62 +++++++++++++++++++++++++------------------------------ 1 file changed, 28 insertions(+), 34 deletions(-) (limited to 'fs/btrfs/raid56.c') diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c index fa72068bd256..0a02e24900aa 100644 --- a/fs/btrfs/raid56.c +++ b/fs/btrfs/raid56.c @@ -851,7 +851,7 @@ static void free_raid_bio(struct btrfs_raid_bio *rbio) * this frees the rbio and runs through all the bios in the * bio_list and calls end_io on them */ -static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, int err, int uptodate) +static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, int err) { struct bio *cur = bio_list_get(&rbio->bio_list); struct bio *next; @@ -864,9 +864,8 @@ static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, int err, int uptodate) while (cur) { next = cur->bi_next; cur->bi_next = NULL; - if (uptodate) - set_bit(BIO_UPTODATE, &cur->bi_flags); - bio_endio(cur, err); + cur->bi_error = err; + bio_endio(cur); cur = next; } } @@ -875,9 +874,10 @@ static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, int err, int uptodate) * end io function used by finish_rmw. When we finally * get here, we've written a full stripe */ -static void raid_write_end_io(struct bio *bio, int err) +static void raid_write_end_io(struct bio *bio) { struct btrfs_raid_bio *rbio = bio->bi_private; + int err = bio->bi_error; if (err) fail_bio_stripe(rbio, bio); @@ -893,7 +893,7 @@ static void raid_write_end_io(struct bio *bio, int err) if (atomic_read(&rbio->error) > rbio->bbio->max_errors) err = -EIO; - rbio_orig_end_io(rbio, err, 0); + rbio_orig_end_io(rbio, err); return; } @@ -1071,7 +1071,7 @@ static int rbio_add_io_page(struct btrfs_raid_bio *rbio, * devices or if they are not contiguous */ if (last_end == disk_start && stripe->dev->bdev && - test_bit(BIO_UPTODATE, &last->bi_flags) && + !last->bi_error && last->bi_bdev == stripe->dev->bdev) { ret = bio_add_page(last, page, PAGE_CACHE_SIZE, 0); if (ret == PAGE_CACHE_SIZE) @@ -1087,7 +1087,6 @@ static int rbio_add_io_page(struct btrfs_raid_bio *rbio, bio->bi_iter.bi_size = 0; bio->bi_bdev = stripe->dev->bdev; bio->bi_iter.bi_sector = disk_start >> 9; - set_bit(BIO_UPTODATE, &bio->bi_flags); bio_add_page(bio, page, PAGE_CACHE_SIZE, 0); bio_list_add(bio_list, bio); @@ -1312,13 +1311,12 @@ write_data: bio->bi_private = rbio; bio->bi_end_io = raid_write_end_io; - BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags)); submit_bio(WRITE, bio); } return; cleanup: - rbio_orig_end_io(rbio, -EIO, 0); + rbio_orig_end_io(rbio, -EIO); } /* @@ -1441,11 +1439,11 @@ static void set_bio_pages_uptodate(struct bio *bio) * This will usually kick off finish_rmw once all the bios are read in, but it * may trigger parity reconstruction if we had any errors along the way */ -static void raid_rmw_end_io(struct bio *bio, int err) +static void raid_rmw_end_io(struct bio *bio) { struct btrfs_raid_bio *rbio = bio->bi_private; - if (err) + if (bio->bi_error) fail_bio_stripe(rbio, bio); else set_bio_pages_uptodate(bio); @@ -1455,7 +1453,6 @@ static void raid_rmw_end_io(struct bio *bio, int err) if (!atomic_dec_and_test(&rbio->stripes_pending)) return; - err = 0; if (atomic_read(&rbio->error) > rbio->bbio->max_errors) goto cleanup; @@ -1469,7 +1466,7 @@ static void raid_rmw_end_io(struct bio *bio, int err) cleanup: - rbio_orig_end_io(rbio, -EIO, 0); + rbio_orig_end_io(rbio, -EIO); } static void async_rmw_stripe(struct btrfs_raid_bio *rbio) @@ -1572,14 +1569,13 @@ static int raid56_rmw_stripe(struct btrfs_raid_bio *rbio) btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56); - BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags)); submit_bio(READ, bio); } /* the actual write will happen once the reads are done */ return 0; cleanup: - rbio_orig_end_io(rbio, -EIO, 0); + rbio_orig_end_io(rbio, -EIO); return -EIO; finish: @@ -1964,7 +1960,7 @@ cleanup_io: else clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags); - rbio_orig_end_io(rbio, err, err == 0); + rbio_orig_end_io(rbio, err); } else if (err == 0) { rbio->faila = -1; rbio->failb = -1; @@ -1976,7 +1972,7 @@ cleanup_io: else BUG(); } else { - rbio_orig_end_io(rbio, err, 0); + rbio_orig_end_io(rbio, err); } } @@ -1984,7 +1980,7 @@ cleanup_io: * This is called only for stripes we've read from disk to * reconstruct the parity. */ -static void raid_recover_end_io(struct bio *bio, int err) +static void raid_recover_end_io(struct bio *bio) { struct btrfs_raid_bio *rbio = bio->bi_private; @@ -1992,7 +1988,7 @@ static void raid_recover_end_io(struct bio *bio, int err) * we only read stripe pages off the disk, set them * up to date if there were no errors */ - if (err) + if (bio->bi_error) fail_bio_stripe(rbio, bio); else set_bio_pages_uptodate(bio); @@ -2002,7 +1998,7 @@ static void raid_recover_end_io(struct bio *bio, int err) return; if (atomic_read(&rbio->error) > rbio->bbio->max_errors) - rbio_orig_end_io(rbio, -EIO, 0); + rbio_orig_end_io(rbio, -EIO); else __raid_recover_end_io(rbio); } @@ -2094,7 +2090,6 @@ static int __raid56_parity_recover(struct btrfs_raid_bio *rbio) btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56); - BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags)); submit_bio(READ, bio); } out: @@ -2102,7 +2097,7 @@ out: cleanup: if (rbio->operation == BTRFS_RBIO_READ_REBUILD) - rbio_orig_end_io(rbio, -EIO, 0); + rbio_orig_end_io(rbio, -EIO); return -EIO; } @@ -2277,11 +2272,12 @@ static int alloc_rbio_essential_pages(struct btrfs_raid_bio *rbio) * end io function used by finish_rmw. When we finally * get here, we've written a full stripe */ -static void raid_write_parity_end_io(struct bio *bio, int err) +static void raid_write_parity_end_io(struct bio *bio) { struct btrfs_raid_bio *rbio = bio->bi_private; + int err = bio->bi_error; - if (err) + if (bio->bi_error) fail_bio_stripe(rbio, bio); bio_put(bio); @@ -2294,7 +2290,7 @@ static void raid_write_parity_end_io(struct bio *bio, int err) if (atomic_read(&rbio->error)) err = -EIO; - rbio_orig_end_io(rbio, err, 0); + rbio_orig_end_io(rbio, err); } static noinline void finish_parity_scrub(struct btrfs_raid_bio *rbio, @@ -2437,7 +2433,7 @@ submit_write: nr_data = bio_list_size(&bio_list); if (!nr_data) { /* Every parity is right */ - rbio_orig_end_io(rbio, 0, 0); + rbio_orig_end_io(rbio, 0); return; } @@ -2450,13 +2446,12 @@ submit_write: bio->bi_private = rbio; bio->bi_end_io = raid_write_parity_end_io; - BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags)); submit_bio(WRITE, bio); } return; cleanup: - rbio_orig_end_io(rbio, -EIO, 0); + rbio_orig_end_io(rbio, -EIO); } static inline int is_data_stripe(struct btrfs_raid_bio *rbio, int stripe) @@ -2524,7 +2519,7 @@ static void validate_rbio_for_parity_scrub(struct btrfs_raid_bio *rbio) return; cleanup: - rbio_orig_end_io(rbio, -EIO, 0); + rbio_orig_end_io(rbio, -EIO); } /* @@ -2535,11 +2530,11 @@ cleanup: * This will usually kick off finish_rmw once all the bios are read in, but it * may trigger parity reconstruction if we had any errors along the way */ -static void raid56_parity_scrub_end_io(struct bio *bio, int err) +static void raid56_parity_scrub_end_io(struct bio *bio) { struct btrfs_raid_bio *rbio = bio->bi_private; - if (err) + if (bio->bi_error) fail_bio_stripe(rbio, bio); else set_bio_pages_uptodate(bio); @@ -2632,14 +2627,13 @@ static void raid56_parity_scrub_stripe(struct btrfs_raid_bio *rbio) btrfs_bio_wq_end_io(rbio->fs_info, bio, BTRFS_WQ_ENDIO_RAID56); - BUG_ON(!test_bit(BIO_UPTODATE, &bio->bi_flags)); submit_bio(READ, bio); } /* the actual write will happen once the reads are done */ return; cleanup: - rbio_orig_end_io(rbio, -EIO, 0); + rbio_orig_end_io(rbio, -EIO); return; finish: -- cgit v1.2.3