similar to: [libguestfs PATCH] lib: remove guestfs_int_cmd_clear_close_files()

Commits 3c27f3d91e1566854747bbe844186783fc84f3a8 and 1b6f0daa9ae7fcc94e389232d0c397816cda973d added an internal API for running commands asynchronously. It is only used by the copy-in and copy-out APIs. Unfortunately this made the command code very complex: it was almost impossible to redirect stderr to a file, and there were a lot of long-range dependencies through the file. It was also buggy:

After fuzzing 'qemu-img info' I found that certain files can cause the command to use lots of memory and time. Modify the command mini-library to allow us to place resource limits on subprocesses, and use these to limit the amount of space and time used by 'qemu-img info'. --- configure.ac | 3 +++ src/command.c | 53

This refactors existing code to close file descriptors in the recovery process, and also adds code to close file descriptors between the fork() and exec() of QEMU or User-Mode Linux. The reason is to avoid leaking main process file descriptors where the main process (or other libraries in the main process) are not setting O_CLOEXEC at all or not setting it atomically. Python is a particular

comments? alternatives: sigsetjmp(ugly) and pselect(not portable, available) drawback: additional filedescriptors. Index: serverloop.c =================================================================== RCS file: /home/markus/cvs/ssh/serverloop.c,v retrieving revision 1.82 diff -u -r1.82 serverloop.c --- serverloop.c 10 Oct 2001 22:18:47 -0000 1.82 +++ serverloop.c 11 Oct 2001 18:06:33 -0000 @@

We recently tried upgrading openssh from 2.5.2p2 to 2.9p1 and discovered that it no longer worked to feed the output from a remote command into a pipe, unless the output was short and the pipe was very fast at processing its input. Example 1: ssh remote_machine some_command | less (where "some_command" generates a lot of output) now fails after the first screenful, with a

The original implementation utilies select(). In Linux select() typically supports up to 1024 file descriptors. This can be a problem when user tries to boot up many guests. Switching to poll() has minimum impact on existing code and has better scalibility. Up to 8192 file descriptors are supported in the current implementation. Signed-off-by: Wei Liu <wei.liu2@citrix.com> ---

Hi, attached there is the second version of the patch series adding copy_in and copy_out in the library, mostly moving them from guestfish. It also adds the copy_in usage in virt-customize, as aid in a new image building. Thanks, Pino Toscano (7): cmd: add a way to run (and wait) asynchronously commands cmd: add a child-setup callback cmd: add the possibility to get a fd to the process

Hi Richard, I see this patch is included into libguestfs >= 1.26.6 & libguestfs >= 1.27.24. I feel that version is too high. Now RHEL 7.0 runs libguestfs-1.22.6, RHEL 6.6 alpha and 6.5 runs libguestfs-1.20.11. Is that possible to backport this patch, in order to make this problem fixed in RHEL 7.0, 6.6, and 6.5? Thanks & Best Regards Qin Zhao (赵钦) China System and Technology Lab,

--- src/command.c | 64 +++++++++++++++++++++++++++++++++++++++++++------- src/guestfs-internal.h | 3 +++ 2 files changed, 58 insertions(+), 9 deletions(-) diff --git a/src/command.c b/src/command.c index 4bb469b..e26573d 100644 --- a/src/command.c +++ b/src/command.c @@ -360,7 +360,7 @@ debug_command (struct command *cmd) } static int -run_command (struct command *cmd)

https://bugzilla.redhat.com/show_bug.cgi?id=1123007 This is version 2 of the patch which avoids incorrectly closing stderr, so we can still see debug and error messages. Rich.

It is just a wrapper around select(2). Signed-off-by: Wei Liu <wei.liu2@citrix.com> --- extras/mini-os/include/posix/poll.h | 1 + extras/mini-os/lib/sys.c | 90 ++++++++++++++++++++++++++++++++++- 2 files changed, 90 insertions(+), 1 deletion(-) create mode 100644 extras/mini-os/include/posix/poll.h diff --git a/extras/mini-os/include/posix/poll.h

From f244bcad756c4f761627557bb7f315b1d8f22fb2 Mon Sep 17 00:00:00 2001 From: Dor Laor <dor.laor@qumranet.com> Date: Thu, 20 Dec 2007 13:26:30 +0200 Subject: [PATCH] [VIRTIO-NET] Rx performance improvement The current performance are not good enough, the problem lies in qemu tap handling code that caused to pass packets one at a time and also to copy them to a temporal buffer. This patch

From f244bcad756c4f761627557bb7f315b1d8f22fb2 Mon Sep 17 00:00:00 2001 From: Dor Laor <dor.laor@qumranet.com> Date: Thu, 20 Dec 2007 13:26:30 +0200 Subject: [PATCH] [VIRTIO-NET] Rx performance improvement The current performance are not good enough, the problem lies in qemu tap handling code that caused to pass packets one at a time and also to copy them to a temporal buffer. This patch

On Friday, 15 December 2017 09:26:29 CET Richard W.M. Jones wrote: > It obscures what's really going on and is no longer necessary > for the original purpose. > > This reverts commit d50cb7bbb4cc18f69ea1425e9f5cee9685825f95. > > See also: > > https://www.redhat.com/archives/libguestfs/2017-November/thread.html#00226 >

The attached patch adds an option (off by default to preserve current behavior) to set a timeout on the select() statement that waits for input in clientloop.c. This fixes a timeout issue for me (explained below) and probably also fixes the timeouts mentioned in last month's thread "Idle time out". The patch is also available by http from:

From: "Richard W.M. Jones" <rjones at redhat.com> If the parent process uses a pipe (or any fd, but pipes are a particular problem), then the recovery process would hold open the file descriptor(s) of the pipe, meaning that it could not be fully closed in the parent. Because the recovery process doesn't use exec(2), this wasn't avoidable even using FD_CLOEXEC. Avoid this

Inspired by libvirt's virCommand* internal mini-library, this adds some internal APIs for running commands. The first patch contains the new APIs. The subsequent patches change various parts of the library over to use it. Rich.

Hello, In response to the timing analysis attacks presented by Dawn Song et. al. in her paper http://paris.cs.berkeley.edu/~dawnsong/ssh-timing.html we at Silicon Defense developed a patch for openssh to avoid such measures. Timing Analysis Evasion changes were developed by C. Jason Coit and Roel Jonkman of Silicon Defense. These changes cause SSH to send packets unless request not to,

Hi all, we're suffering heavily from the "connection reset by peer" problem when running Rsync on WinNT. Great was our relief when seeing Randy's message in http://www.mail-archive.com/rsync@lists.samba.org/msg01918.html I immediately installed the full Cygwin to recompile Rsync, but since I'm far from a C guru, I'm a bit puzzled with the last 2 lines in Randy's

Hello, ? I need to make many (>50) ssh connections from linux to cygwin at the same time. Using Windows 2000 Server (OpenSSH_4.3p2, OpenSSL 0.9.8b and updated cygwin) and Linux RHEL4 (OpenSSH_3.9p1, OpenSSL 0.9.7a). ? It's been difficult to optimize many simultaneous connections. Here were some issues: 1.?????? On Windows XP/Professional, Microsoft intentionally cripples the TCP/IP stack.