Bug #10153: File.open block does not throw "No space left on device (Errno::ENOSPC)" if the data fits the buffer of IO.write

• Status: Closed
• Assignee: matz (Yukihiro Matsumoto)
• Target version: 2.2.0
• ruby -v: ruby 1.9.3p484 (2013-11-22) [x86_64-linux]
• Backport: 2.0.0: DONE, 2.1: DONE

[butching314 (Marvin Reyes)]

When writing to file in disk using File.open with a block as an argument, if the diskspace is full and IO.write does not flush right away, the block just exits successfully instead of throwing Errno:ENOSPC.

Setup: Drive partition needs to be full

Eg. of a write that will succeed normally with no exception given that the drive is full (this means that the expected failure is being swallowed)

File.open('/full_drive/test.txt','wb') do |file|
  file.write("test")
end

#This will complete normally because the "test" data does not get flushed
#This will leave a 0kb file on the disk

Eg. force a flush to see the error

File.open('/full_drive/test.txt','wb') do |file|
  file.write("test")
  file.flush
end

#This will throw Errno::ENOSPC
#This will leave a 0kb file on the disk

Eg. write a large enough data that file.write will flush by itself (most likely it hits the buffer cap)

fills = '1'*1048576
File.open('/full_drive/test.txt','wb') do |file|
  file.write(fills)
end

#This will throw Errno::ENOSPC
#This will leave a 0kb file on the disk

Eg. When not using File.open block argument and closing the IO with an ensure block

begin
  io = File.open('/full_drive/test.txt', 'wb')
  io.write("test")
ensure
  io.close
end

#This will throw Errno::ENOSPC
#This will leave a 0kb file on the disk

Currently tested in RHEL5.

Notes:

• I've encountered this in ruby-1.9.2
• I've tested this with ruby-2.1.2
• I'm not sure if the issue is because of File.open usage of c-extension rb_ensure or io_close. reference: (http://ruby-doc.org/core-1.9.3/File.html#method-c-open)

[znz (Kazuhiro NISHIYAMA)]

• Priority changed from 5 to Normal
• Target version changed from 2.6 to 2.2.0

I can reproduce 2.2.0dev with /dev/full.

% ruby -ve 'File.open("/dev/full", "w"){|f|f.puts "test"}'
ruby 2.2.0dev (2014-06-28 trunk 46598) [x86_64-linux]
% ruby -ve 'File.open("/dev/full", "w"){|f|f.puts "test"; f.flush}'
ruby 2.2.0dev (2014-06-28 trunk 46598) [x86_64-linux]
-e:1:in `flush': No space left on device (Errno::ENOSPC)
        from -e:1:in `block in <main>'
        from -e:1:in `open'
        from -e:1:in `<main>'
%

[nobu (Nobuyoshi Nakada)]

• Status changed from Open to Assigned
• Assignee set to matz (Yukihiro Matsumoto)

This behavior was introduced at r10623 by matz, but the commit log is only:

* io.c (io_close): always calls "close" method of the receiver.
  [ruby-core:6911] [ruby-core:8112]

[nobu (Nobuyoshi Nakada)]

• Status changed from Assigned to Closed
• % Done changed from 0 to 100

Applied in changeset r47288.

---

io.c: do not swallow exceptions at end of block

• io.c (io_close): ignore only "closed stream" IOError and
  NoMethodError, do not swallow other exceptions at the end of
  block. [ruby-core:64463] [Bug #10153]

[nobu (Nobuyoshi Nakada)]

Seems intended to ignore IOError and NoMethodError.

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.0.0: UNKNOWN, 2.1: UNKNOWN to 2.0.0: REQUIRED, 2.1: REQUIRED

[butching314 (Marvin Reyes)]

What is the conclusion for this post?

[nagachika (Tomoyuki Chikanaga)]

• Backport changed from 2.0.0: REQUIRED, 2.1: REQUIRED to 2.0.0: REQUIRED, 2.1: DONE

Backported into ruby_2_1 branch at r47486.

[usa (Usaku NAKAMURA)]

• Backport changed from 2.0.0: REQUIRED, 2.1: DONE to 2.0.0: DONE, 2.1: DONE

backported into ruby_2_0_0 at r47503.

[shyouhei (Shyouhei Urabe)]

• Related to Bug #13405: IO#close raises "stream closed" added