More fixes from bde.
Only modify times on success. splhigh() around time variable usage. Make atomic writes more posix compliant. Spelling errors. Submitted by: bde
This commit is contained in:
John Dyson
parent
96cc6b1011
commit
f29e1bd629
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=13913
@ -40,7 +40,7 @@
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* process.
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*
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* If the sending process receives a signal, it is possible that it will
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* go away, and certainly it's address space can change, because control
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* go away, and certainly its address space can change, because control
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* is returned back to the user-mode side. In that case, the pipe code
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* arranges to copy the buffer supplied by the user process, to a pageable
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* kernel buffer, and the receiving process will grab the data from the
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@ -49,7 +49,7 @@
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*
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* The constant PIPE_MINDIRECT is chosen to make sure that buffering will
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* happen for small transfers so that the system will not spend all of
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* it's time context switching. PIPE_SIZE is constrained by the
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* its time context switching. PIPE_SIZE is constrained by the
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* amount of kernel virtual memory.
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*/
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@ -223,6 +223,7 @@ static void
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pipeinit(cpipe)
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struct pipe *cpipe;
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{
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int s;
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cpipe->pipe_buffer.in = 0;
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cpipe->pipe_buffer.out = 0;
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@ -234,9 +235,11 @@ pipeinit(cpipe)
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cpipe->pipe_state = 0;
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cpipe->pipe_peer = NULL;
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cpipe->pipe_busy = 0;
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s = splhigh();
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cpipe->pipe_ctime = time;
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cpipe->pipe_atime = time;
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cpipe->pipe_mtime = time;
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splx(s);
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bzero(&cpipe->pipe_sel, sizeof cpipe->pipe_sel);
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/*
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@ -340,7 +343,6 @@ pipe_read(fp, uio, cred)
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rpipe->pipe_buffer.cnt -= size;
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nread += size;
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rpipe->pipe_atime = time;
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/*
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* Direct copy, bypassing a kernel buffer.
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*/
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@ -357,7 +359,6 @@ pipe_read(fp, uio, cred)
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if (error)
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break;
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nread += size;
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rpipe->pipe_atime = time;
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rpipe->pipe_map.pos += size;
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rpipe->pipe_map.cnt -= size;
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if (rpipe->pipe_map.cnt == 0) {
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@ -387,7 +388,7 @@ pipe_read(fp, uio, cred)
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/*
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* If there is no more to read in the pipe, reset
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* it's pointers to the beginning. This improves
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* its pointers to the beginning. This improves
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* cache hit stats.
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*/
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@ -407,6 +408,12 @@ pipe_read(fp, uio, cred)
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}
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}
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if (error == 0) {
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int s = splhigh();
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rpipe->pipe_atime = time;
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splx(s);
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}
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--rpipe->pipe_busy;
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if ((rpipe->pipe_busy == 0) && (rpipe->pipe_state & PIPE_WANT)) {
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rpipe->pipe_state &= ~(PIPE_WANT|PIPE_WANTW);
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@ -414,7 +421,7 @@ pipe_read(fp, uio, cred)
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} else if (rpipe->pipe_buffer.cnt < MINPIPESIZE) {
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/*
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* If there is no more to read in the pipe, reset
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* it's pointers to the beginning. This improves
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* its pointers to the beginning. This improves
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* cache hit stats.
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*/
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if ((error == 0) && (error = pipelock(rpipe,1)) == 0) {
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@ -645,6 +652,7 @@ pipewrite(wpipe, uio, nbio)
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int nbio;
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{
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int error = 0;
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int orig_resid;
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/*
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* detect loss of pipe read side, issue SIGPIPE if lost.
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@ -663,6 +671,7 @@ pipewrite(wpipe, uio, nbio)
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}
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++wpipe->pipe_busy;
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orig_resid = uio->uio_resid;
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while (uio->uio_resid) {
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int space;
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/*
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@ -693,13 +702,14 @@ pipewrite(wpipe, uio, nbio)
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}
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space = wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt;
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if ((space < uio->uio_resid) && (orig_resid <= PIPE_BUF))
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space = 0;
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/*
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* We must afford contiguous writes on buffers of size
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* PIPE_BUF or less.
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*/
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if ((space > 0) &&
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((uio->uio_resid > PIPE_BUF) || (uio->uio_resid <= space))) {
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if (space > 0) {
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int size = wpipe->pipe_buffer.size - wpipe->pipe_buffer.in;
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if (size > space)
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size = space;
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@ -726,7 +736,6 @@ pipewrite(wpipe, uio, nbio)
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wpipe->pipe_buffer.in = 0;
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wpipe->pipe_buffer.cnt += size;
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wpipe->pipe_mtime = time;
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} else {
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/*
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* If the "read-side" has been blocked, wake it up now.
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@ -780,6 +789,12 @@ pipewrite(wpipe, uio, nbio)
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(uio->uio_resid == 0) &&
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(error == EPIPE))
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error = 0;
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if (error = 0) {
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int s = splhigh();
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wpipe->pipe_mtime = time;
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splx(s);
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}
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if (wpipe->pipe_state & PIPE_SEL) {
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wpipe->pipe_state &= ~PIPE_SEL;
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@ -855,7 +870,6 @@ pipe_select(fp, which, p)
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{
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register struct pipe *rpipe = (struct pipe *)fp->f_data;
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struct pipe *wpipe;
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register int s = splnet();
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wpipe = rpipe->pipe_peer;
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switch (which) {
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@ -863,7 +877,6 @@ pipe_select(fp, which, p)
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case FREAD:
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if (rpipe->pipe_buffer.cnt > 0 ||
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(rpipe->pipe_state & PIPE_EOF)) {
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splx(s);
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return (1);
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}
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selrecord(p, &rpipe->pipe_sel);
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@ -874,7 +887,6 @@ pipe_select(fp, which, p)
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if ((wpipe == NULL) ||
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(wpipe->pipe_state & PIPE_EOF) ||
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((wpipe->pipe_buffer.size - wpipe->pipe_buffer.cnt) >= PIPE_BUF)) {
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splx(s);
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return (1);
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}
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selrecord(p, &wpipe->pipe_sel);
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@ -885,7 +897,6 @@ pipe_select(fp, which, p)
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if ((rpipe->pipe_state & PIPE_EOF) ||
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(wpipe == NULL) ||
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(wpipe->pipe_state & PIPE_EOF)) {
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splx(s);
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return (1);
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}
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@ -893,7 +904,6 @@ pipe_select(fp, which, p)
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rpipe->pipe_state |= PIPE_SEL;
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break;
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}
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splx(s);
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return (0);
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}
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