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Re: propagating repo corruption across clone

From
ILIlari Liusvaara <ilari.liusvaara@elisanet.fi>
Date
Mar 24, 2013, 19:16 UTC
Message-ID
<20130324191614.GA15275@LK-Perkele-VII>
In-Reply-To
<20130324183133.GA11200@sigill.intra.peff.net>
On Sun, Mar 24, 2013 at 02:31:33PM -0400, Jeff King wrote:
Show 8 quoted lines
> 
> Fscking the incoming objects does work, but of course it comes at a cost
> in the normal case (for linux-2.6, I measured an increase in CPU time
> with "index-pack --strict" from ~2.5 minutes to ~4 minutes). And I think
> it is probably overkill for finding corruption; index-pack already
> recognizes bit corruption inside an object, and
> check_everything_connected can detect object graph problems much more
> cheaply.

AFAIK, standard checks index-pack has to do + checking that the object graph has no broken links (and every ref points to something valid) will catch everything except:

- SHA-1 collisions between corrupt objects and clean ones.
- Corrupted refs (that still point to something valid).
- "Born-corrupted" objects.
> One thing I didn't check is bit corruption inside a packed object that
> still correctly zlib inflates. check_everything_connected will end up
> reading all of the commits and trees (to walk them), but not the blobs.

Checking that everything is connected will (modulo SHA-1 collisions) save you there, at least if packv3 is used as transport stream.

-Ilari
Previous: Duy NguyenNext: Junio C Hamano
Message 28 of 60 in “propagating repo corruption across clone”
  1. Jeff KingMar 24, 2013
  2. Ævar Arnfjörð BjarmasonMar 24, 2013
  3. Jeff KingMar 24, 2013
  4. Jeff MitchellMar 25, 2013
  5. Jeff KingMar 25, 2013
  6. Duy NguyenMar 25, 2013
  7. Jeff KingMar 25, 2013
  8. Jeff MitchellMar 25, 2013
  9. Jeff KingMar 25, 2013
  10. Jeff MitchellMar 26, 2013
  11. Jeff KingMar 26, 2013
  12. Philip OakleyMar 26, 2013
  13. Jeff KingMar 26, 2013
  14. Rich FrommMar 26, 2013
  15. Jonathan NiederMar 27, 2013
  16. Rich FrommMar 27, 2013
  17. Jeff KingMar 27, 2013
  18. Jeff KingMar 27, 2013
  19. Junio C HamanoMar 27, 2013
  20. Sitaram ChamartyMar 27, 2013
  21. Junio C HamanoMar 27, 2013
  22. Sitaram ChamartyMar 27, 2013
  23. Rich FrommMar 27, 2013
  24. Junio C HamanoMar 27, 2013
  25. Jeff MitchellMar 28, 2013
  26. Jeff MitchellMar 28, 2013
  27. Duy NguyenMar 26, 2013
  28. Ilari LiusvaaraMar 24, 2013
  29. Junio C HamanoMar 25, 2013
  30. Jeff KingMar 25, 2013
  31. 0/9 corrupt object potpourriJeff King, Mar 25, 2013
  32. 1/9 stream_blob_to_fd: detect errors reading from streamJeff King, Mar 25, 2013
  33. Junio C HamanoMar 26, 2013
  34. 2/9 check_sha1_signature: check return value from read_istreamJeff King, Mar 25, 2013
  35. 3/9 read_istream_filtered: propagate read error from upstreamJeff King, Mar 25, 2013
  36. 4/9 avoid infinite loop in read_istream_looseJeff King, Mar 25, 2013
  37. 5/9 add test for streaming corrupt blobsJeff King, Mar 25, 2013
  38. Jonathan NiederMar 25, 2013
  39. Jeff KingMar 25, 2013
  40. Jeff KingMar 27, 2013
  41. Junio C HamanoMar 27, 2013
  42. 6/9 streaming_write_entry: propagate streaming errorsJeff King, Mar 25, 2013
  43. Eric SunshineMar 25, 2013
  44. Jeff KingMar 25, 2013
  45. Jonathan NiederMar 25, 2013
  46. 6/9 streaming_write_entry: propagate streaming errorsJeff King, Mar 25, 2013
  47. Jonathan NiederMar 25, 2013
  48. Junio C HamanoMar 26, 2013
  49. 7/9 add tests for cloning corrupted repositoriesJeff King, Mar 25, 2013
  50. 8/9 clone: die on errors from unpack_treesJeff King, Mar 25, 2013
  51. Junio C HamanoMar 26, 2013
  52. 10/9 clone: leave repo in place after checkout errorsJeff King, Mar 26, 2013
  53. Jonathan NiederMar 26, 2013
  54. Jeff KingMar 27, 2013
  55. 9/9 clone: run check_everything_connectedJeff King, Mar 25, 2013
  56. Duy NguyenMar 26, 2013
  57. Jeff KingMar 26, 2013
  58. Junio C HamanoMar 26, 2013
  59. Duy NguyenMar 28, 2013
  60. Duy NguyenMar 31, 2013

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