block: Add should_fail_bio() for bpf error injection (30abb3a6) · Commits · 戴 / test

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>

block/blk-core.c

+10 −1

Original line number	Diff line number	Diff line
		@@ -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) {

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