Patch for rc.d/devd on FreeBSD 9-current
des at des.no
Mon Jun 28 08:40:42 UTC 2010
Dag-Erling Smørgrav <des at des.no> writes:
> "M. Warner Losh" <imp at bsdimp.com> writes:
>> Maybe the real problem is that devd locks the file, then dies. The
>> file remains locked, so the flopen is failing with EWOULDBLOCK.
> The lock is released when the process that holds it terminates.
>> But I suspect the real real problem is the implicit assumption that
>> flock will release the lock when a process terminates... That isn't
>> the case in BSD
> Yes it is.
- Under POSIX semantics (fcntl(2) locks), the lock is released when
*any* file descriptor the process holds for that file is closed.
This is handled in fdfree().
- Under flock semantics (flock(2) locks), the lock is released when
*all* file descriptors the process holds for that file is closed.
This is handled in vn_closefile().
- In both cases, all locks a process holds are released when the
Gotta love the following excerpt from VOP_OPEN(9), btw:
The VOP_OPEN() entry point is called before a file is accessed by a
process and the VOP_CLOSE() entry point is called after a file is fin‐
ished with by the process.
Dag-Erling Smørgrav - des at des.no
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