summaryrefslogtreecommitdiff
path: root/drivers/md/dm.c
diff options
context:
space:
mode:
authorChristoph Hellwig <hch@lst.de>2015-07-20 15:29:37 +0200
committerJens Axboe <axboe@fb.com>2015-07-29 08:55:15 -0600
commit4246a0b63bd8f56a1469b12eafeb875b1041a451 (patch)
tree3281bb158d658ef7f208ad380c0ecee600a5ab5e /drivers/md/dm.c
parent0034af036554c39eefd14d835a8ec3496ac46712 (diff)
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 <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'drivers/md/dm.c')
-rw-r--r--drivers/md/dm.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f331d888e7f5..7f367fcace03 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -944,7 +944,8 @@ static void dec_pending(struct dm_io *io, int error)
} else {
/* done with normal IO or empty flush */
trace_block_bio_complete(md->queue, bio, io_error);
- bio_endio(bio, io_error);
+ bio->bi_error = io_error;
+ bio_endio(bio);
}
}
}
@@ -957,17 +958,15 @@ static void disable_write_same(struct mapped_device *md)
limits->max_write_same_sectors = 0;
}
-static void clone_endio(struct bio *bio, int error)
+static void clone_endio(struct bio *bio)
{
+ int error = bio->bi_error;
int r = error;
struct dm_target_io *tio = container_of(bio, struct dm_target_io, clone);
struct dm_io *io = tio->io;
struct mapped_device *md = tio->io->md;
dm_endio_fn endio = tio->ti->type->end_io;
- if (!bio_flagged(bio, BIO_UPTODATE) && !error)
- error = -EIO;
-
if (endio) {
r = endio(tio->ti, bio, error);
if (r < 0 || r == DM_ENDIO_REQUEUE)
@@ -996,7 +995,7 @@ static void clone_endio(struct bio *bio, int error)
/*
* Partial completion handling for request-based dm
*/
-static void end_clone_bio(struct bio *clone, int error)
+static void end_clone_bio(struct bio *clone)
{
struct dm_rq_clone_bio_info *info =
container_of(clone, struct dm_rq_clone_bio_info, clone);
@@ -1013,13 +1012,13 @@ static void end_clone_bio(struct bio *clone, int error)
* the remainder.
*/
return;
- else if (error) {
+ else if (bio->bi_error) {
/*
* Don't notice the error to the upper layer yet.
* The error handling decision is made by the target driver,
* when the request is completed.
*/
- tio->error = error;
+ tio->error = bio->bi_error;
return;
}