[PATCH] make sys_open respect FASYNC

[M.J. Pomraning]

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Please roll your eyeballs over the following -- idea is to have open(blah,
O_ASYNC) work as expected (device permitting), and not to leave the caller
with an fd with a frustrated flag.

Successfully applied against 2.4.14.  Simple test case (for ttys) attached.
Previous post [1] has more about motivation and scope (incl. FIFOs) of this
somewhat obscure concern.

=============================
--- linux/fs/open.c.orig        Wed Nov 14 09:53:36 2001
+++ linux/fs/open.c     Wed Nov 14 15:34:33 2001
@@ -789,6 +789,15 @@
                        error = PTR_ERR(f);
                        if (IS_ERR(f))
                                goto out_error;
+                       /* handle open(foo, O_ASYNC|...) */
+                       if ((f->f_flags & FASYNC) &&
+                            f->f_op && f->f_op->fasync) {
+                               error = f->f_op->fasync(fd, f, 1);
+                               if (error < 0) {
+                                       filp_close(f, NULL);
+                                       goto out_error;
+                               }
+                       }
                        fd_install(fd, f);
                }
 out:
=============================

Notes:

[1] "open(O_ASYNC) sets futile flag"
    http://www.uwsg.indiana.edu/hypermail/linux/kernel/0111.1/1401.html

Regards,
Mike
-- 
MJ Pomraning
[e-mail]

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