[New-bugs-announce] [issue35179] Limit max sendfile chunk to 0x7ffff000

[Andrew Svetlov]

New submission from Andrew Svetlov <andrew.svetlov at gmail.com>:

On Linux maximum data size for sendfile call is 0x7ffff000: 

sendfile() will transfer at most 0x7ffff000 (2,147,479,552) bytes,  returning  the  number  of  bytes  actually
transferred.  (This is true on both 32-bit and 64-bit systems.)

Limiting max block size to this value on all OSes makes sense: splitting transferring the very huge file into several syscalls doesn't hurt performance anyway.

Windows uses DWORD for size in TransmitFile, so the size is limited as well.

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components: macOS
messages: 329366
nosy: asvetlov, ned.deily, ronaldoussoren
priority: normal
severity: normal
status: open
title: Limit max sendfile chunk to 0x7ffff000
versions: Python 3.7, Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue35179>
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