Mercurial > hg > nginx
annotate src/os/unix/ngx_linux_aio_read.c @ 7142:b9d919b53593 stable-1.12
Stream: relaxed next upstream condition (ticket #1317).
When switching to a next upstream, some buffers could be stuck in the middle
of the filter chain. A condition existed that raised an error when this
happened. As it turned out, this condition prevented switching to a next
upstream if ssl preread was used with the TCP protocol (see the ticket).
In fact, the condition does not make sense for TCP, since after successful
connection to an upstream switching to another upstream never happens. As for
UDP, the issue with stuck buffers is unlikely to happen, but is still possible.
Specifically, if a filter delays sending data to upstream.
The condition can be relaxed to only check the "buffered" bitmask of the
upstream connection. The new condition is simpler and fixes the ticket issue
as well. Additionally, the upstream_out chain is now reset for UDP prior to
connecting to a new upstream to prevent repeating the client data twice.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 11 Sep 2017 15:32:31 +0300 |
parents | f01ab2dbcfdc |
children |
rev | line source |
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3052 | 1 |
2 /* | |
3 * Copyright (C) Igor Sysoev | |
4412 | 4 * Copyright (C) Nginx, Inc. |
3052 | 5 */ |
6 | |
7 | |
8 #include <ngx_config.h> | |
9 #include <ngx_core.h> | |
10 #include <ngx_event.h> | |
11 | |
12 | |
13 extern int ngx_eventfd; | |
14 extern aio_context_t ngx_aio_ctx; | |
15 | |
16 | |
17 static void ngx_file_aio_event_handler(ngx_event_t *ev); | |
18 | |
19 | |
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20 static int |
3052 | 21 io_submit(aio_context_t ctx, long n, struct iocb **paiocb) |
22 { | |
23 return syscall(SYS_io_submit, ctx, n, paiocb); | |
24 } | |
25 | |
26 | |
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27 ngx_int_t |
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28 ngx_file_aio_init(ngx_file_t *file, ngx_pool_t *pool) |
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29 { |
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30 ngx_event_aio_t *aio; |
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31 |
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32 aio = ngx_pcalloc(pool, sizeof(ngx_event_aio_t)); |
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33 if (aio == NULL) { |
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34 return NGX_ERROR; |
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35 } |
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36 |
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37 aio->file = file; |
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38 aio->fd = file->fd; |
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39 aio->event.data = aio; |
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40 aio->event.ready = 1; |
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41 aio->event.log = file->log; |
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42 |
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43 file->aio = aio; |
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44 |
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45 return NGX_OK; |
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46 } |
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47 |
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48 |
3052 | 49 ssize_t |
50 ngx_file_aio_read(ngx_file_t *file, u_char *buf, size_t size, off_t offset, | |
51 ngx_pool_t *pool) | |
52 { | |
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Fixing Linux AIO syscalls return value handling:
Igor Sysoev <igor@sysoev.ru>
parents:
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53 ngx_err_t err; |
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54 struct iocb *piocb[1]; |
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55 ngx_event_t *ev; |
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56 ngx_event_aio_t *aio; |
3052 | 57 |
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58 if (!ngx_file_aio) { |
3052 | 59 return ngx_read_file(file, buf, size, offset); |
60 } | |
61 | |
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62 if (file->aio == NULL && ngx_file_aio_init(file, pool) != NGX_OK) { |
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63 return NGX_ERROR; |
3052 | 64 } |
65 | |
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66 aio = file->aio; |
3052 | 67 ev = &aio->event; |
68 | |
69 if (!ev->ready) { | |
70 ngx_log_error(NGX_LOG_ALERT, file->log, 0, | |
71 "second aio post for \"%V\"", &file->name); | |
72 return NGX_AGAIN; | |
73 } | |
74 | |
75 ngx_log_debug4(NGX_LOG_DEBUG_CORE, file->log, 0, | |
6480 | 76 "aio complete:%d @%O:%uz %V", |
3052 | 77 ev->complete, offset, size, &file->name); |
78 | |
79 if (ev->complete) { | |
80 ev->active = 0; | |
81 ev->complete = 0; | |
82 | |
83 if (aio->res >= 0) { | |
84 ngx_set_errno(0); | |
85 return aio->res; | |
86 } | |
87 | |
88 ngx_set_errno(-aio->res); | |
4076
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Bugfix: open_file_cache lost is_directio flag.
Maxim Dounin <mdounin@mdounin.ru>
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89 |
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90 ngx_log_error(NGX_LOG_CRIT, file->log, ngx_errno, |
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91 "aio read \"%s\" failed", file->name.data); |
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92 |
3052 | 93 return NGX_ERROR; |
94 } | |
95 | |
96 ngx_memzero(&aio->aiocb, sizeof(struct iocb)); | |
97 | |
98 aio->aiocb.aio_data = (uint64_t) (uintptr_t) ev; | |
99 aio->aiocb.aio_lio_opcode = IOCB_CMD_PREAD; | |
100 aio->aiocb.aio_fildes = file->fd; | |
101 aio->aiocb.aio_buf = (uint64_t) (uintptr_t) buf; | |
102 aio->aiocb.aio_nbytes = size; | |
103 aio->aiocb.aio_offset = offset; | |
104 aio->aiocb.aio_flags = IOCB_FLAG_RESFD; | |
105 aio->aiocb.aio_resfd = ngx_eventfd; | |
106 | |
107 ev->handler = ngx_file_aio_event_handler; | |
108 | |
109 piocb[0] = &aio->aiocb; | |
110 | |
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6903dac6ad19
Fixing Linux AIO syscalls return value handling:
Igor Sysoev <igor@sysoev.ru>
parents:
4076
diff
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111 if (io_submit(ngx_aio_ctx, 1, piocb) == 1) { |
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112 ev->active = 1; |
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113 ev->ready = 0; |
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parents:
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114 ev->complete = 0; |
cd04f652478c
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Igor Sysoev <igor@sysoev.ru>
parents:
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115 |
3052 | 116 return NGX_AGAIN; |
117 } | |
118 | |
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Fixing Linux AIO syscalls return value handling:
Igor Sysoev <igor@sysoev.ru>
parents:
4076
diff
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119 err = ngx_errno; |
3052 | 120 |
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6903dac6ad19
Fixing Linux AIO syscalls return value handling:
Igor Sysoev <igor@sysoev.ru>
parents:
4076
diff
changeset
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121 if (err == NGX_EAGAIN) { |
3052 | 122 return ngx_read_file(file, buf, size, offset); |
123 } | |
124 | |
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6903dac6ad19
Fixing Linux AIO syscalls return value handling:
Igor Sysoev <igor@sysoev.ru>
parents:
4076
diff
changeset
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125 ngx_log_error(NGX_LOG_CRIT, file->log, err, |
3052 | 126 "io_submit(\"%V\") failed", &file->name); |
127 | |
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Igor Sysoev <igor@sysoev.ru>
parents:
4076
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128 if (err == NGX_ENOSYS) { |
3294
04cfc09b8b8d
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Igor Sysoev <igor@sysoev.ru>
parents:
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129 ngx_file_aio = 0; |
3052 | 130 return ngx_read_file(file, buf, size, offset); |
131 } | |
132 | |
133 return NGX_ERROR; | |
134 } | |
135 | |
136 | |
137 static void | |
138 ngx_file_aio_event_handler(ngx_event_t *ev) | |
139 { | |
140 ngx_event_aio_t *aio; | |
141 | |
142 aio = ev->data; | |
143 | |
144 ngx_log_debug2(NGX_LOG_DEBUG_CORE, ev->log, 0, | |
145 "aio event handler fd:%d %V", aio->fd, &aio->file->name); | |
146 | |
147 aio->handler(ev); | |
148 } |