diff --git a/sys/fs/fifofs/fifo_vnops.c b/sys/fs/fifofs/fifo_vnops.c index e544bba..716faa3 100644 --- a/sys/fs/fifofs/fifo_vnops.c +++ b/sys/fs/fifofs/fifo_vnops.c @@ -64,6 +64,8 @@ struct fifoinfo { struct pipe *fi_pipe; long fi_readers; long fi_writers; + u_int fi_rgen; + u_int fi_wgen; }; static vop_print_t fifo_print; @@ -137,6 +139,7 @@ fifo_open(ap) struct thread *td; struct fifoinfo *fip; struct pipe *fpipe; + u_int gen; int error, stops_deferred; vp = ap->a_vp; @@ -164,6 +167,7 @@ fifo_open(ap) PIPE_LOCK(fpipe); if (ap->a_mode & FREAD) { fip->fi_readers++; + fip->fi_rgen++; if (fip->fi_readers == 1) { fpipe->pipe_state &= ~PIPE_EOF; if (fip->fi_writers > 0) @@ -179,6 +183,7 @@ fifo_open(ap) return (ENXIO); } fip->fi_writers++; + fip->fi_wgen++; if (fip->fi_writers == 1) { fpipe->pipe_state &= ~PIPE_EOF; if (fip->fi_readers > 0) @@ -187,6 +192,7 @@ fifo_open(ap) } if ((ap->a_mode & O_NONBLOCK) == 0) { if ((ap->a_mode & FREAD) && fip->fi_writers == 0) { + gen = fip->fi_wgen; VOP_UNLOCK(vp, 0); stops_deferred = sigallowstop(); error = msleep(&fip->fi_readers, PIPE_MTX(fpipe), @@ -194,7 +200,7 @@ fifo_open(ap) if (stops_deferred) sigdeferstop(); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); - if (error) { + if (error != 0 && gen == fip->fi_wgen) { fip->fi_readers--; if (fip->fi_readers == 0) { PIPE_LOCK(fpipe); @@ -214,6 +220,7 @@ fifo_open(ap) */ } if ((ap->a_mode & FWRITE) && fip->fi_readers == 0) { + gen = fip->fi_rgen; VOP_UNLOCK(vp, 0); stops_deferred = sigallowstop(); error = msleep(&fip->fi_writers, PIPE_MTX(fpipe), @@ -221,7 +228,7 @@ fifo_open(ap) if (stops_deferred) sigdeferstop(); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); - if (error) { + if (error != 0 && gen == fip->fi_rgen) { fip->fi_writers--; if (fip->fi_writers == 0) { PIPE_LOCK(fpipe);