Messages in this thread Patch in this message | | | Date | Mon, 10 Jun 2002 03:48:43 +0100 | From | Matthew Wilcox <> | Subject | [PATCH] fs/locks.c: Fix posix locking for threaded tasks |
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Saurabh Desai believes that locks created by threads should not conflict with each other. I'm inclined to agree; I don't know why the test for ->fl_pid was added, but the comment suggests that whoever added it wasn't sure either.
Frankly, I have no clue about the intended semantics for threads, and SUS v3 does not offer any enlightenment. But it seems reasonable that processes which share a files_struct should share locks. After all, if one process closes the fd, they'll remove locks belonging to the other process.
Here's a patch generated against 2.4; it also applies to 2.5. Please apply.
===== fs/locks.c 1.9 vs edited ===== --- 1.9/fs/locks.c Mon Jun 3 18:49:43 2002 +++ edited/fs/locks.c Fri Jun 7 21:24:12 2002 @@ -380,15 +380,12 @@ } /* - * Check whether two locks have the same owner - * N.B. Do we need the test on PID as well as owner? - * (Clone tasks should be considered as one "owner".) + * Locks are deemed to have the same owner if the tasks share files_struct. */ static inline int locks_same_owner(struct file_lock *fl1, struct file_lock *fl2) { - return (fl1->fl_owner == fl2->fl_owner) && - (fl1->fl_pid == fl2->fl_pid); + return (fl1->fl_owner == fl2->fl_owner); } /* Remove waiter from blocker's block list. -- Revolutions do not require corporate support. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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