Messages in this thread Patch in this message | | | Date | Thu, 9 Oct 2003 02:52:32 +0100 | From | Jamie Lokier <> | Subject | [PATCH] set sigio target to current->pid and only if not already set |
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Patch: f_setown-2.6.0-test6.patch
Dear Linus,
Two minor changes:
1. send_sigio() sends to a specific thread, _not_ a process. (It can also send to a process group, but that's not relevant here). This is useful, and should stay as it is.
Therefore it makes _no sense_ to call f_setown() with current->tgid. Presently the kernel is inconsistent about it, with some places using current->pid and some others using current->tgid.
This patch changes f_setown() calls to use current->pid.
2. In some places, f_setown() is called not at the user's direct request, but as a side effect of another function. Specifically: dnotify and file leases.
It is good to allow a program the flexibility to specify a different pid than the default, using F_SETOWN. Presently they can do this after the dnotify or lease call, but there is a small time window when it will be temporarily set to current->tgid (which as pointed out above, is not always right).
The window is avoidable if the program can use F_SETOWN prior to the dnotify or lease call. This is exactly what the "force" argument to f_setown() is for, and this patch changes it to zero in those callers.
This change is not likely to affect any existing programs.
Please apply.
-- Jamie
diff -urN --exclude-from=dontdiff orig-2.6.0-test6/fs/dnotify.c f_setown-2.6.0-test6/fs/dnotify.c --- orig-2.6.0-test6/fs/dnotify.c 2003-09-13 21:21:25.000000000 +0100 +++ f_setown-2.6.0-test6/fs/dnotify.c 2003-10-09 01:49:13.000000000 +0100 @@ -92,7 +92,7 @@ prev = &odn->dn_next; } - error = f_setown(filp, current->tgid, 1); + error = f_setown(filp, current->pid, 0); if (error) goto out_free; diff -urN --exclude-from=dontdiff orig-2.6.0-test6/fs/locks.c f_setown-2.6.0-test6/fs/locks.c --- orig-2.6.0-test6/fs/locks.c 2003-09-30 05:40:50.000000000 +0100 +++ f_setown-2.6.0-test6/fs/locks.c 2003-10-09 01:49:37.000000000 +0100 @@ -1268,7 +1268,7 @@ locks_insert_lock(before, fl); - error = f_setown(filp, current->tgid, 1); + error = f_setown(filp, current->pid, 0); out_unlock: unlock_kernel(); return error; diff -urN --exclude-from=dontdiff orig-2.6.0-test6/kernel/futex.c f_setown-2.6.0-test6/kernel/futex.c --- orig-2.6.0-test6/kernel/futex.c 2003-09-30 05:41:14.000000000 +0100 +++ f_setown-2.6.0-test6/kernel/futex.c 2003-10-09 01:52:37.000000000 +0100 @@ -500,7 +500,7 @@ if (signal) { int err; - err = f_setown(filp, current->tgid, 1); + err = f_setown(filp, current->pid, 1); if (err < 0) { put_unused_fd(ret); put_filp(filp); - 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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