diff options
author | dyson <dyson@FreeBSD.org> | 1996-03-17 04:52:10 +0000 |
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committer | dyson <dyson@FreeBSD.org> | 1996-03-17 04:52:10 +0000 |
commit | fb28135c8b0893363bc99979b1db4dc4f0301693 (patch) | |
tree | 0a4097e119a743d690584d1a03af8148cf9544e5 /sys/kern/sys_pipe.c | |
parent | f5f9b2ee23f286f9f5932ac00601b253ec59836c (diff) | |
download | FreeBSD-src-fb28135c8b0893363bc99979b1db4dc4f0301693.zip FreeBSD-src-fb28135c8b0893363bc99979b1db4dc4f0301693.tar.gz |
Yet another fix from BDE for the new pipe code. This fixes a potential
deadlock due to mismanagement of busy counters.
Reviewed by: dyson
Submitted by: bde
Diffstat (limited to 'sys/kern/sys_pipe.c')
-rw-r--r-- | sys/kern/sys_pipe.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/sys/kern/sys_pipe.c b/sys/kern/sys_pipe.c index fb73f19..9bc3bf3 100644 --- a/sys/kern/sys_pipe.c +++ b/sys/kern/sys_pipe.c @@ -16,7 +16,7 @@ * 4. Modifications may be freely made to this file if the above conditions * are met. * - * $Id: sys_pipe.c,v 1.12 1996/02/17 14:47:16 peter Exp $ + * $Id: sys_pipe.c,v 1.13 1996/02/22 03:33:52 dyson Exp $ */ #ifndef OLD_PIPE @@ -759,13 +759,12 @@ pipewrite(wpipe, uio, nbio) } space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt; + + /* Writes of size <= PIPE_BUF must be atomic. */ + /* XXX perhaps they need to be contiguous to be atomic? */ if ((space < uio->uio_resid) && (orig_resid <= PIPE_BUF)) space = 0; - /* - * We must afford contiguous writes on buffers of size - * PIPE_BUF or less. - */ if (space > 0) { int size = wpipe->pipe_buffer.size - wpipe->pipe_buffer.in; if (size > space) @@ -831,6 +830,7 @@ pipewrite(wpipe, uio, nbio) } } + --wpipe->pipe_busy; if ((wpipe->pipe_busy == 0) && (wpipe->pipe_state & PIPE_WANT)) { wpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTR); @@ -866,7 +866,6 @@ pipewrite(wpipe, uio, nbio) if (wpipe->pipe_buffer.cnt) pipeselwakeup(wpipe); - --wpipe->pipe_busy; return error; } |