block: Add should_fail_bio() for bpf error injection

The classic error injection mechanism, should_fail_request() does not
support use cases where more information is required (from the entire
struct bio, for example).

To that end, this patch introduces should_fail_bio(), which calls
should_fail_request() under the hood but provides a convenient
place for kprobes to hook into if they require the entire struct bio.
This patch also replaces some existing calls to should_fail_request()
with should_fail_bio() with no degradation in performance.

Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Howard McLauchlan 2018-02-06 14:05:39 -08:00 committed by Jens Axboe
parent 5235553d82
commit 30abb3a67f

View File

@ -34,6 +34,7 @@
#include <linux/pm_runtime.h>
#include <linux/blk-cgroup.h>
#include <linux/debugfs.h>
#include <linux/bpf.h>
#define CREATE_TRACE_POINTS
#include <trace/events/block.h>
@ -2083,6 +2084,14 @@ static inline bool bio_check_ro(struct bio *bio, struct hd_struct *part)
return false;
}
static noinline int should_fail_bio(struct bio *bio)
{
if (should_fail_request(&bio->bi_disk->part0, bio->bi_iter.bi_size))
return -EIO;
return 0;
}
ALLOW_ERROR_INJECTION(should_fail_bio, ERRNO);
/*
* Remap block n of partition p to block n+start(p) of the disk.
*/
@ -2174,7 +2183,7 @@ generic_make_request_checks(struct bio *bio)
if ((bio->bi_opf & REQ_NOWAIT) && !queue_is_rq_based(q))
goto not_supported;
if (should_fail_request(&bio->bi_disk->part0, bio->bi_iter.bi_size))
if (should_fail_bio(bio))
goto end_io;
if (!bio->bi_partno) {