Hi Lukas, > I have patch ready, would you be able to test it before posting it. > > Let me know if I should build the kernel for you or just share the source > with you. OK. Please share the git tree and specify the branch to test. Akira On 2016/07/29 15:25, Lukas Herbolt wrote: > Hi Akira, > Sorry I was on holiday. > I have patch ready, would you be able to test it before posting it. > > Let me know if I should build the kernel for you or just share the source > with you. > > Lukas > > On Sun, Jul 17, 2016 at 3:36 AM, Akira Hayakawa <ruby.wktk@xxxxxxxxx> wrote: > >>> 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. >> >> btw, is this fix going to be included in the next release? >> >> On 2016/07/06 21:54, Akira Hayakawa wrote: >>> 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
