On Wed, Jan 24, 2018 at 03:22:58PM -0800, Howard McLauchlan wrote: > 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.
Reviewed-by: Omar Sandoval <[email protected]> Jens, can we pick this up for 4.16? The necessary BPF support has been merged into Linus' tree. > Signed-off-by: Howard McLauchlan <[email protected]> > --- > block/blk-core.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index b8881750a3ac..5e73c996d338 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -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> > @@ -2050,6 +2051,12 @@ static inline bool should_fail_request(struct > hd_struct *part, > > #endif /* CONFIG_FAIL_MAKE_REQUEST */ > > +static noinline bool should_fail_bio(struct bio *bio) > +{ > + return should_fail_request(&bio->bi_disk->part0, bio->bi_iter.bi_size); > +} > +BPF_ALLOW_ERROR_INJECTION(should_fail_bio); > + > /* > * Remap block n of partition p to block n+start(p) of the disk. > */ > @@ -2141,7 +2148,7 @@ 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 (blk_partition_remap(bio)) > -- > 2.14.1 >
