Thanks, I want the patch in the main-tree quickly. Because without it, my tests will not be green. This is really annoying. I made a quick reproducer of this problem. If you are looking for one, this will help. (You need to install sbt first) https://github.com/akiradeveloper/writeboost-test-suite test("flakey (read)") { Memory(Sector.M(16)) { a => Flakey.Table(a, 0, 1).create { b => intercept[Exception] { Shell(s"dd status=none if=${b.bdev.path} iflag=direct of=/dev/null") } } } } $ sudo sbt "testOnly dmtest.FlakeyTest" 12:44:00.643 [pool-2-thread-3-ScalaTest-running-FlakeyTest] INFO dmtest - [TEST] flakey (read) 12:44:00.752 [pool-2-thread-3-ScalaTest-running-FlakeyTest] DEBUG dmtest - reload: table=0 32768 flakey /dev/loop0 0 0 1 [info] FlakeyTest: [info] - flakey (read) *** FAILED *** [info] Expected exception java.lang.Exception to be thrown, but no exception was thrown. (FlakeyTest.scala:9) [info] Run completed in 2 seconds, 781 milliseconds. [info] Total number of tests run: 1 [info] Suites: completed 1, aborted 0 [info] Tests: succeeded 0, failed 1, canceled 0, ignored 0, pending 0 - Akira On 2016/07/06 18:52, Lukas Herbolt wrote: > Hi, > Yes this part is wrong and reads are not dropped. > I have a patch ready, just have to send it out. > > Lukas > > On Wed, Jul 6, 2016 at 8:33 AM, Akira Hayakawa <ruby.wktk@xxxxxxxxx> wrote: > >> Hi, >> >> I am using dm-flakey to emulate a broken device that should return -EIO on >> both read and write. >> I use the parameter up_interval=0 and down_interval=1. >> >> But when I am dd-ing the flakey device, while write fails, read succeeds. >> This isn't the behavior I expect. >> >> Then I looked into the code. >> >> 326 static int flakey_end_io(struct dm_target *ti, struct bio *bio, int >> error) >> 327 { >> 328 struct flakey_c *fc = ti->private; >> 329 struct per_bio_data *pb = dm_per_bio_data(bio, sizeof(struct >> per_bio_data)); >> 330 >> 331 /* >> 332 * Corrupt successful READs while in down state. >> 333 * If flags were specified, only corrupt those that match. >> 334 */ >> 335 if (fc->corrupt_bio_byte && !error && pb->bio_submitted && >> 336 (bio_data_dir(bio) == READ) && (fc->corrupt_bio_rw == >> READ) && >> 337 all_corrupt_bio_flags_match(bio, fc)) >> 338 corrupt_bio_data(bio, fc); >> 339 >> 340 return error; >> 341 } >> >> When the bio direction is READ and currupt_bio_bytes isn't specified >> the READ bio is handled normally right? >> >> I think READ requests should return -EIO if >> >> 1. corrupt_bio_bytes isn't specified >> 2. but the requested is handled during down interval. >> >> as well as WRITE requests: >> >> 305 /* >> 306 * Corrupt matching writes. >> 307 */ >> 308 if (fc->corrupt_bio_byte && (fc->corrupt_bio_rw == >> WRITE)) { >> 309 if (all_corrupt_bio_flags_match(bio, fc)) >> 310 corrupt_bio_data(bio, fc); >> 311 goto map_bio; >> 312 } >> 313 >> 314 /* >> 315 * By default, error all I/O. >> 316 */ >> 317 return -EIO; >> 318 } >> >> This code is similar to what we see in the end_io. >> >> If my understanding is correct, I would like to modify dm-flakey to return >> -EIO in the end_io. >> >> I would like to request for comments. >> >> Thanks, >> >> - Akira >> >> -- >> dm-devel mailing list >> dm-devel@xxxxxxxxxx >> https://www.redhat.com/mailman/listinfo/dm-devel >> > > > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
