Bug 30449
| Summary: | NFS lock manager grants multiple locks on same file | ||
|---|---|---|---|
| Product: | Base System | Reporter: | Andrew Lentvorski <buzmeg> |
| Component: | bin | Assignee: | freebsd-bugs (Nobody) <bugs> |
| Status: | Closed FIXED | ||
| Severity: | Affects Only Me | ||
| Priority: | Normal | ||
| Version: | Unspecified | ||
| Hardware: | Any | ||
| OS: | Any | ||
State Changed From-To: open->closed This is the documented behaviour of rpc.lockd on 4.x and earlier. 5.x has a complete implementation that should not suffer from this problem. |
Multiple requests to exclusively lock a file over NFS will succeed. I stumbled across this behavior when using a Solaris box to use fcntl to do a SETLKW (sample program is available if desired). The use of SETLKW bypasses the normal cacheing of lock requests when initiated by the same client. Thus, you have to set up the following scenario: Client 1 ---------------------- V NFS Server ^ Client 2 ---------------------- In order to test even the basic SETLK behavior since there is no longer any cacheing going on at the client level. Once you bypass the local cacheing, FreeBSD will hand out lock and unlock requests multiple times on the same file. I would dearly love to have the developer of the rpc.lockd code contact me so that I can help write (or at least carry out) regression tests for the NFS locking system. How-To-Repeat: See above, or contact me for a sample program.