Hello Mikulas, On 10/10/12 08:57, Mikulas Patocka wrote: > On Tue, 9 Oct 2012, Bill Pemberton wrote: > >> I'm seeing an oops with the patch >> http://people.redhat.com/agk/patches/linux/editing/dm-store-dm_target_io-in-bio-front_pad.patch >> in linux-next (commit 24d047b). >> >> I'll attach the dmesg output from a crash. I bisected it down to this >> one patch and verified that reverting it results in a kernel that >> boots normally. It appears that this will crash any linux-next kernel >> since 20120918 -- I've not tried them all, but I have tried a few. >> >> The machines where this happens are Dell PowerEdge SC1425 I haven't actually tried linux-next but the following code misses actual cloning after alloc_tio(). (Your patch removed bio_clone_bioset()) Doesn't it cause flush request to be issued unprepared? 1121 static void __issue_target_request(struct clone_info *ci, struct dm_target *ti, 1122 unsigned request_nr, sector_t len) 1123 { 1124 struct dm_target_io *tio = alloc_tio(ci, ti, ci->bio->bi_max_vecs); 1125 struct bio *clone = &tio->clone; 1126 1127 tio->info.target_request_nr = request_nr; 1128 1129 /* 1130 * Discard requests require the bio's inline iovecs be initialized. 1131 * ci->bio->bi_max_vecs is BIO_INLINE_VECS anyway, for both flush 1132 * and discard, so no need for concern about wasted bvec allocations. 1133 */ 1134 1135 if (len) { 1136 clone->bi_sector = ci->sector; 1137 clone->bi_size = to_bytes(len); 1138 } 1139 1140 __map_bio(ti, tio); -- Jun'ichi Nomura, NEC Corporation -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
