Date: Wed, 01 Aug 2018 12:37:46 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 230259] [FUSE] [BUG]: File close (release) issue Message-ID: <bug-230259-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230259 Bug ID: 230259 Summary: [FUSE] [BUG]: File close (release) issue Product: Base System Version: 11.1-RELEASE Hardware: Any URL: https://robo.moosefs.com/support/fuse_helloworld.tgz OS: Any Status: New Severity: Affects Some People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: freebsd@moosefs.com This is one of three issues we detected in FreeBSD FUSE while developing our distributed file system. All four issues can be replicated using this simple test script: https://robo.moosefs.com/support/fuse_helloworld.tgz When an I/O operation (for example read) takes a bit long and the process that performed the read operation is killed (i.e. with 9 signal), kernel does not wait for the operation to complete but immediately sends release. Since FUSE is multithreaded, one's program can get the release before the read (race condition), effectively ending up reading data from an already closed descriptor into no-longer-existing structures. We handled that issue in our system by making reference counters and delaying release (lots of FreeBSD specific code), but since FUSE behaviour on Linux is completely different and FUSE was first developed on Linux, we feel some consitency is warranted. Best regards, Peter / MooseFS Team -- You are receiving this mail because: You are the assignee for the bug.help
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