Opened 10 years ago

Closed 7 years ago

#585 closed defect (fixed)

SSI include subrequests fails in big POST reply

Reported by: Hervé Bry Owned by:
Priority: minor Milestone:
Component: nginx-core Version: 1.7.x
Keywords: ssi proxy Cc:
uname -a: Linux dev-www.liancourt.gnet #1 SMP Sun May 22 21:22:07 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
nginx -V: nginx version: nginx/1.7.2
built by gcc 4.4.3 (GCC)
TLS SNI support enabled
configure arguments: --with-http_stub_status_module --with-http_ssl_module --with-http_secure_link_module --with-http_sub_module --with-http_realip_module --with-ipv6 --prefix=/var/lib/nginx --sbin-path=/usr/sbin/nginx --conf-path=/etc/nginx/nginx.conf --pid-path=/var/run/ --lock-path=/var/lock/nginx.lock --error-log-path=/var/log/nginx/error.log --http-log-path=/var/log/nginx/access.log --http-client-body-temp-path=/var/lib/nginx/body --http-proxy-temp-path=/var/lib/nginx/proxy --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --add-module=nginx-upload-progress-module-master


In the following situation:

  • nginx is used as a proxy
  • SSI processing is enabled on nginx
  • a POST request is big enough that the body needs to be stored on disk
  • the reply of the POST request contains SSI include tags

The subrequests generated by the SSI includes fails with the following error :
[crit] 18249#0: *8455632166 pread() "/var/lib/nginx/body/0047817306" failed (9: Bad file descriptor) while sending request to upstream

In the end, the 502 error page is included instead of the requested URIs.

Reproducible using the following files:

location / {

ssi on;
proxy_pass http://backend;




<form action="test.html" enctype="multipart/form-data" method="post">

<input type="file" name="f"/>
<input type="submit"/>

<p><!--# include virtual="include.html" --></p>



This text will be included in test.html

Change History (4)

comment:1 by Hervé Bry, 10 years ago

The test file names disappeared in the bug description, but the first one is obviously the config, then test.html and include.html.

Version 0, edited 10 years ago by Hervé Bry (next)

comment:2 by Maxim Dounin, 10 years ago

Keywords: proxy added
Status: newaccepted

Thanks, this is known problem which happens due to an optimization in proxy module: request body cache file is released once a response is got. If later a subrequest tries to use body, it fails. It's unlikely to be fixed in foreseeable future though. Workaround is to use "proxy_pass_request_body off" for subrequests.

comment:3 by Roman Arutyunyan <arut@…>, 7 years ago

In 7070:f583559aadc7/nginx:

Upstream: keep request body file from removal if requested.

The new request flag "preserve_body" indicates that the request body file should
not be removed by the upstream module because it may be used later by a
subrequest. The flag is set by the SSI (ticket #585), addition and slice
modules. Additionally, it is also set by the upstream module when a background
cache update subrequest is started to prevent the request body file removal
after an internal redirect. Only the main request is now allowed to remove the

comment:4 by Roman Arutyunyan, 7 years ago

Resolution: fixed
Status: acceptedclosed
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