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/linear.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/md/linear.c') diff --git a/drivers/md/linear.c b/drivers/md/linear.c index fa7d577..aefd661 100644 --- a/drivers/md/linear.c +++ b/drivers/md/linear.c @@ -297,7 +297,7 @@ static void linear_make_request(struct mddev *mddev, struct bio *bio) if (unlikely((split->bi_rw & REQ_DISCARD) && !blk_queue_discard(bdev_get_queue(split->bi_bdev)))) { /* Just ignore it */ - bio_endio(split, 0); + bio_endio(split); } else generic_make_request(split); } while (split != bio); -- cgit v1.1 From 8ae126660fddbeebb9251a174e6fa45b6ad8f932 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Mon, 27 Apr 2015 23:48:34 -0700 Subject: block: kill merge_bvec_fn() completely As generic_make_request() is now able to handle arbitrarily sized bios, it's no longer necessary for each individual block driver to define its own ->merge_bvec_fn() callback. Remove every invocation completely. Cc: Jens Axboe Cc: Lars Ellenberg Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina Cc: Yehuda Sadeh Cc: Sage Weil Cc: Alex Elder Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon Cc: Mike Snitzer Cc: dm-devel@redhat.com Cc: Neil Brown Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig Cc: "Martin K. Petersen" Acked-by: NeilBrown (for the 'md' bits) Acked-by: Mike Snitzer Signed-off-by: Kent Overstreet [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park Signed-off-by: Ming Lin Signed-off-by: Jens Axboe --- drivers/md/linear.c | 43 ------------------------------------------- 1 file changed, 43 deletions(-) (limited to 'drivers/md/linear.c') diff --git a/drivers/md/linear.c b/drivers/md/linear.c index aefd661..b7fe7e9 100644 --- a/drivers/md/linear.c +++ b/drivers/md/linear.c @@ -52,48 +52,6 @@ static inline struct dev_info *which_dev(struct mddev *mddev, sector_t sector) return conf->disks + lo; } -/** - * linear_mergeable_bvec -- tell bio layer if two requests can be merged - * @q: request queue - * @bvm: properties of new bio - * @biovec: the request that could be merged to it. - * - * Return amount of bytes we can take at this offset - */ -static int linear_mergeable_bvec(struct mddev *mddev, - struct bvec_merge_data *bvm, - struct bio_vec *biovec) -{ - struct dev_info *dev0; - unsigned long maxsectors, bio_sectors = bvm->bi_size >> 9; - sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev); - int maxbytes = biovec->bv_len; - struct request_queue *subq; - - dev0 = which_dev(mddev, sector); - maxsectors = dev0->end_sector - sector; - subq = bdev_get_queue(dev0->rdev->bdev); - if (subq->merge_bvec_fn) { - bvm->bi_bdev = dev0->rdev->bdev; - bvm->bi_sector -= dev0->end_sector - dev0->rdev->sectors; - maxbytes = min(maxbytes, subq->merge_bvec_fn(subq, bvm, - biovec)); - } - - if (maxsectors < bio_sectors) - maxsectors = 0; - else - maxsectors -= bio_sectors; - - if (maxsectors <= (PAGE_SIZE >> 9 ) && bio_sectors == 0) - return maxbytes; - - if (maxsectors > (maxbytes >> 9)) - return maxbytes; - else - return maxsectors << 9; -} - static int linear_congested(struct mddev *mddev, int bits) { struct linear_conf *conf; @@ -338,7 +296,6 @@ static struct md_personality linear_personality = .size = linear_size, .quiesce = linear_quiesce, .congested = linear_congested, - .mergeable_bvec = linear_mergeable_bvec, }; static int __init linear_init (void) -- cgit v1.1