https://bugzilla.kernel.org/show_bug.cgi?id=208827 --- Comment #14 from Dave Chinner (david@xxxxxxxxxxxxx) --- On Mon, Aug 10, 2020 at 08:19:57PM -0600, Jens Axboe wrote: > On 8/10/20 8:00 PM, Dave Chinner wrote: > > On Mon, Aug 10, 2020 at 07:08:59PM +1000, Dave Chinner wrote: > >> On Mon, Aug 10, 2020 at 05:08:07PM +1000, Dave Chinner wrote: > >>> [cc Jens] > >>> > >>> [Jens, data corruption w/ io_uring and simple fio reproducer. see > >>> the bz link below.] > > > > Looks like a io_uring/fio bugs at this point, Jens. All your go fast > > bits turns the buffered read into a short read, and neither fio nor > > io_uring async buffered read path handle short reads. Details below. > > It's a fio issue. The io_uring engine uses a different path for short > IO completions, and that's being ignored by the backend... Hence the > IO just gets completed and not retried for this case, and that'll then > trigger verification as if it did complete. I'm fixing it up. I just updated fio to: cb7d7abb (HEAD -> master, origin/master, origin/HEAD) io_u: set io_u->verify_offset in fill_io_u() The workload still reports corruption almost instantly. Only this time, the trace is not reporting a short read. File is patterned with: verify_pattern=0x33333333%o-16 Offset of "bad" data is 0x1240000. Expected: 00000000: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000010: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000020: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000030: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000040: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000050: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000060: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000070: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000080: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ ..... 0000ffd0: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 0000ffe0: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ 0000fff0: 33 33 33 33 00 10 24 01 00 00 00 00 f0 ff ff ff 3333............ Received: 00000000: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000010: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000020: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000030: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000040: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000050: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000060: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000070: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 00000080: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ ..... 0000ffd0: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 0000ffe0: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ 0000fff0: 33 33 33 33 00 00 24 01 00 00 00 00 f0 ff ff ff 3333............ Looks like the data in the expected buffer is wrong - the data pattern in the received buffer is correct according the defined pattern. Error is 100% reproducable from the same test case. Same bad byte in the expected buffer dump every single time. -Dave. -- You are receiving this mail because: You are watching the assignee of the bug.
