[tahoe-lafs-trac-stream] [Tahoe-LAFS] #1794: upload failed -- "I/O operation on closed file"

[Tahoe-LAFS]

#1794: upload failed -- "I/O operation on closed file"
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     Reporter:  zooko         |      Owner:
         Type:  defect        |     Status:  new
     Priority:  normal        |  Milestone:  undecided
    Component:  code-network  |    Version:  1.9.2
   Resolution:                |   Keywords:  upload error twisted
Launchpad Bug:                |
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Comment (by daira):

 Replying to [comment:7 zooko]:
 > The hypothesis is that Nevow is `close()`'ing the temp file in
 [https://github.com/twisted/nevow/blob/master/nevow/static.py#L391
 stopProducing]. The hypothesis is that Nevow is done producing, but Tahoe-
 LAFS isn't yet done consuming!

 That seems plausible to me. To test it, we should instrument Nevow to log
 when it is closing the temp file; if this log entry comes just before the
 "I/O operation on closed file", then we've confirmed the hypothesis.

 It also seems plausible that we can work around this by `os.dup`'ing the
 file handle when we get it (in `render_{PUT,POST}`), and closing our
 duplicate when we are finished. (I am assuming that Nevow cannot already
 have closed the file when we first get it; that would be a Nevow bug that
 we can't fix.)

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Ticket URL: <https://tahoe-lafs.org/trac/tahoe-lafs/ticket/1794#comment:8>
Tahoe-LAFS <https://Tahoe-LAFS.org>
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