#1033 Crash when copying to different places in parallel

[AL89]

Hi,
I found out that pcmanfm may crash when more than one copy operation is going on in parallel.

pcmanfm/libfm version: 1.2.4

Operating system: Ubuntu 16.04 and Debian testing

Steps to reproduce:

• start copying a directory with multiple files to e.g. "Dir1" (single files seem not to trigger the bug)
• while the copy is ongoing, start copying another directory with multiple files to a different destination, e.g. "Dir2"
• when the copy to Dir1 finishes, pcmanfm crashes, regardless of the state of the copy to Dir2. If it was still ongoing, some files end up being corrupted.

Backtrace: attached.

Let me know if more information is needed.

[Lonely Stranger]

Thank you very much for a backtrace. It seems good, hope to fix the probllem soon.

[Lonely Stranger]

Thank you very much. I believe this issue is fixed in current libfm GIT sources now. Check it when possible, please, and report back if something isn't fixed yet.

[AL89]

The issue seems to be fixed in libfm 1.2.5. Thank you very much!

[Adam]

I'm running libfm 1.2.5 on Arch, and am afraid to say that, in addition to having this issue in the past, still occasionally have it now! One of the times (which was for sure with 1.2.5) was when doing a copy across SAMBA shares, but others were just normal local copies.

It always 'felt' to me that it was more likely when, not merely performing multiple copies at once, actually explicitly changing directories in one of the open pcmanfm windows (or sub-panes, when using the F3 mode). And of course, what happens is a segfault, killing dead all other active copies.

I keep trying to get some more info on this when it happens, but it's just too inconsistent.

[Adam]

I was able to reproduce the bug in the following situation:

• Start a large copy from a remote NFS share onto a gvfs-mtp mounted device (my Phone's SD card)
• [the copy was large enough to have an ETA much longer than these actions]
• Continue navigating through the remote NFS share for another thing to copy
• Select something else, put its path(s) into the clipborad (i.e. press Ctrl+C)
• Do some more navigation, with the intent to paste into the same target directory as the first, still-running copy

I believe I had the two folders (source and target) open in pcmanfm tabs of the same window. At some point before I got the 2nd copy going, pcmanfm just crashed on me. It was noticably slow to load the contents of directories as I was browsing at this time, presumably due to the ongoing copy operation.

When pcmanfm/libfm crashed, it does the usual hard-termination of the current operation (i.e. it doesn't seem to keep going to empty the /proc/meminfo Dirty cache, it just stops).

I've attached the systemd journalctl log from the crash. I've uploaded the coredump to a couple of different filehosts. Original filename: core.pcmanfm.1000.7abd32d3855c49b2995e547ef7496992.23093.1507619774000000.lz4

https://u.teknik.io/ai3pD.lz4
https://www.dropbox.com/s/3vlb51c9tr8xxxs/core.pcmanfm.1000.7abd32d3855c49b2995e547ef7496992.23093.1507619774000000.lz4?dl=0

I have some other coredumps in that dropbox folder pertaining to pcmanfm which might be of interest, but are probably from other issues I've reported/commented-on. https://www.dropbox.com/sh/aa9r5i7e8ecj0td/AADPbrZ02g7hJv6sAiAmNqFWa?dl=0

[Adam]

I've rebuilt libfm and pcmanfm with debugging symbols enabled (actually, -git for each, as I was unable to progress past complaints from the build system of the form 'recreate aclocal.m4 and run automake again'), and once I can reproduce, will submit some hopefully more useful info.