svn commit: r368265 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Tue Dec  1 22:53:33 2020
New Revision: 368265
URL: https://svnweb.freebsd.org/changeset/base/368265

Log:
  lio_listio(2): send signal even if number of jobs is zero.
  
  Right now, if lio registered zero jobs, syscall frees lio job
  structure, cleaning up queued ksi.  As result, the realtime signal is
  dequeued and never delivered.
  
  Fix it by allowing sendsig() to copy ksi when job count is zero.
  
  PR: 220398
  Reported and reviewed by:	asomers
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week
  Differential revision:	https://reviews.freebsd.org/D27421

Modified:
  head/sys/kern/vfs_aio.c

Modified: head/sys/kern/vfs_aio.c
==============================================================================
--- head/sys/kern/vfs_aio.c	Tue Dec  1 22:46:51 2020	(r368264)
+++ head/sys/kern/vfs_aio.c	Tue Dec  1 22:53:33 2020	(r368265)
@@ -466,7 +466,7 @@ aio_init_aioinfo(struct proc *p)
 }
 
 static int
-aio_sendsig(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi)
+aio_sendsig(struct proc *p, struct sigevent *sigev, ksiginfo_t *ksi, bool ext)
 {
 	struct thread *td;
 	int error;
@@ -477,7 +477,7 @@ aio_sendsig(struct proc *p, struct sigevent *sigev, ks
 	if (!KSI_ONQ(ksi)) {
 		ksiginfo_set_sigev(ksi, sigev);
 		ksi->ksi_code = SI_ASYNCIO;
-		ksi->ksi_flags |= KSI_EXT | KSI_INS;
+		ksi->ksi_flags |= ext ? (KSI_EXT | KSI_INS) : 0;
 		tdsendsignal(p, td, ksi->ksi_signo, ksi);
 	}
 	PROC_UNLOCK(p);
@@ -896,7 +896,7 @@ aio_bio_done_notify(struct proc *userp, struct kaiocb 
 
 	if (job->uaiocb.aio_sigevent.sigev_notify == SIGEV_SIGNAL ||
 	    job->uaiocb.aio_sigevent.sigev_notify == SIGEV_THREAD_ID)
-		aio_sendsig(userp, &job->uaiocb.aio_sigevent, &job->ksi);
+		aio_sendsig(userp, &job->uaiocb.aio_sigevent, &job->ksi, true);
 
 	KNOTE_LOCKED(&job->klist, 1);
 
@@ -909,7 +909,8 @@ aio_bio_done_notify(struct proc *userp, struct kaiocb 
 		    == LIOJ_SIGNAL &&
 		    (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL ||
 		    lj->lioj_signal.sigev_notify == SIGEV_THREAD_ID)) {
-			aio_sendsig(userp, &lj->lioj_signal, &lj->lioj_ksi);
+			aio_sendsig(userp, &lj->lioj_signal, &lj->lioj_ksi,
+			    true);
 			lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
 		}
 	}
@@ -2238,7 +2239,8 @@ kern_lio_listio(struct thread *td, int mode, struct ai
 			    LIOJ_SIGNAL_POSTED)) == LIOJ_SIGNAL &&
 			    (lj->lioj_signal.sigev_notify == SIGEV_SIGNAL ||
 			    lj->lioj_signal.sigev_notify == SIGEV_THREAD_ID)) {
-				aio_sendsig(p, &lj->lioj_signal, &lj->lioj_ksi);
+				aio_sendsig(p, &lj->lioj_signal, &lj->lioj_ksi,
+				    lj->lioj_count != 1);
 				lj->lioj_flags |= LIOJ_SIGNAL_POSTED;
 			}
 		}