On 18/07/2019 2:59 pm, Milan Broz wrote: > On 18/07/2019 15:49, Tom Eccles wrote: >> On 18/07/2019 2:09 pm, Milan Broz wrote: >>> On 18/07/2019 13:41, Tom Eccles wrote: >>>> On 17/07/2019 8:49 pm, Milan Broz wrote: >>>>> If you can still reproduce it, please send version of the utility and >>>>> kernel (and --debug output as suggested in another mail) and if you have some >>>>> data/hash/fec images that can be used to reproduce it, let me know where I can find it. >>>> >>>> Attached is a bash script gen_image.sh which should reproduce the issue. >>>> find_and_corrupt.c should be in the working directory when gen_image.sh is >>>> run. find_and_corrupt.c corrupts the disk image by simply searching for a >>>> known string and introducing an error (see the diff outputted by gen_image.sh). >>>> >>>> See in particular the error and dmesg sample when reading the corrupted file >>>> (gen_image.sh:77) and the success when running veritysetup verify >>>> (gen_image.sh:86). >>>> >>>> I have created an issue at https://gitlab.com/cryptsetup/cryptsetup/issues/462 >>> >>> Thanks. >>> >>> I think I see the problem, and it is actually not FEC related. >>> >>> Could you please try to manually allocate loop devices in RW mode (not read-only >>> as we have during automatic loop allocation if mapping image is in file) >>> over the provided images, and then use these loop device as arguments for >>> the veritysetup? >>> >>> Like >>> # losetup /dev/loop0 data8M.img.corrupt >>> # losetup /dev/loop1 hash-img >>> # losetup /dev/loop2 fec-img >>> >>> and >>> >>> # veritysetup open --fec-roots 24 --fec-device /dev/loop2 /dev/loop0 test /dev/loop1 15546e6799bb13608c77fa9cb840682a2dec3cfdb948d942ff3487f537966c01 --debug >>> >>> Does it correct the data now? For me it prints >>> >>> kernel: device-mapper: verity: sha256 using implementation "sha256-generic" >>> kernel: fec_decode_bufs: 13 callbacks suppressed >>> kernel: device-mapper: verity-fec: 7:0: FEC 0: corrected 153 errors >>> >>> Milan >>> >> >> This is not working for me. > > ok, I actually just tried dd the whole device, not through the mounted fs. > will try it later... > > But anyway, it seems like a problem with some infrastructure inside dm/block layer > and not the FEC algorithm itself (errno -74 is EBADMSG, something that should not be here). > > m. > Thanks. I will have a look around there. _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx https://www.saout.de/mailman/listinfo/dm-crypt
