Mercurial > hg > nginx-quic
view src/stream/ngx_stream_write_filter_module.c @ 6876:a5d1b1383dea
Upstream: fixed cache corruption and socket leaks with aio_write.
The ngx_event_pipe() function wasn't called on write events with
wev->delayed set. As a result, threaded writing results weren't
properly collected in ngx_event_pipe_write_to_downstream() when a
write event was triggered for a completed write.
Further, this wasn't detected, as p->aio was reset by a thread completion
handler, and results were later collected in ngx_event_pipe_read_upstream()
instead of scheduling a new write of additional data. If this happened
on the last reading from an upstream, last part of the response was never
written to the cache file.
Similar problems might also happen in case of timeouts when writing to
client, as this also results in ngx_event_pipe() not being called on write
events. In this scenario socket leaks were observed.
Fix is to check if p->writing is set in ngx_event_pipe_read_upstream(), and
therefore collect results of previous write operations in case of read events
as well, similar to how we do so in ngx_event_pipe_write_downstream().
This is enough to fix the wev->delayed case. Additionally, we now call
ngx_event_pipe() from ngx_http_upstream_process_request() if there are
uncollected write operations (p->writing and !p->aio). This also fixes
the wev->timedout case.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Fri, 20 Jan 2017 21:14:19 +0300 |
parents | 56fc55e32f23 |
children | a7ff19afbb14 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { ngx_chain_t *from_upstream; ngx_chain_t *from_downstream; } ngx_stream_write_filter_ctx_t; static ngx_int_t ngx_stream_write_filter(ngx_stream_session_t *s, ngx_chain_t *in, ngx_uint_t from_upstream); static ngx_int_t ngx_stream_write_filter_init(ngx_conf_t *cf); static ngx_stream_module_t ngx_stream_write_filter_module_ctx = { NULL, /* preconfiguration */ ngx_stream_write_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_write_filter_module = { NGX_MODULE_V1, &ngx_stream_write_filter_module_ctx, /* module context */ NULL, /* module directives */ NGX_STREAM_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_int_t ngx_stream_write_filter(ngx_stream_session_t *s, ngx_chain_t *in, ngx_uint_t from_upstream) { off_t size; ngx_uint_t last, flush, sync; ngx_chain_t *cl, *ln, **ll, **out, *chain; ngx_connection_t *c; ngx_stream_write_filter_ctx_t *ctx; ctx = ngx_stream_get_module_ctx(s, ngx_stream_write_filter_module); if (ctx == NULL) { ctx = ngx_pcalloc(s->connection->pool, sizeof(ngx_stream_write_filter_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_stream_set_ctx(s, ctx, ngx_stream_write_filter_module); } if (from_upstream) { c = s->connection; out = &ctx->from_upstream; } else { c = s->upstream->peer.connection; out = &ctx->from_downstream; } if (c->error) { return NGX_ERROR; } size = 0; flush = 0; sync = 0; last = 0; ll = out; /* find the size, the flush point and the last link of the saved chain */ for (cl = *out; cl; cl = cl->next) { ll = &cl->next; ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0, "write old buf t:%d f:%d %p, pos %p, size: %z " "file: %O, size: %O", cl->buf->temporary, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last - cl->buf->pos, cl->buf->file_pos, cl->buf->file_last - cl->buf->file_pos); #if 1 if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "zero size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } #endif size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->recycled) { flush = 1; } if (cl->buf->sync) { sync = 1; } if (cl->buf->last_buf) { last = 1; } } /* add the new chain to the existent one */ for (ln = in; ln; ln = ln->next) { cl = ngx_alloc_chain_link(c->pool); if (cl == NULL) { return NGX_ERROR; } cl->buf = ln->buf; *ll = cl; ll = &cl->next; ngx_log_debug7(NGX_LOG_DEBUG_EVENT, c->log, 0, "write new buf t:%d f:%d %p, pos %p, size: %z " "file: %O, size: %O", cl->buf->temporary, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last - cl->buf->pos, cl->buf->file_pos, cl->buf->file_last - cl->buf->file_pos); #if 1 if (ngx_buf_size(cl->buf) == 0 && !ngx_buf_special(cl->buf)) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "zero size buf in writer " "t:%d r:%d f:%d %p %p-%p %p %O-%O", cl->buf->temporary, cl->buf->recycled, cl->buf->in_file, cl->buf->start, cl->buf->pos, cl->buf->last, cl->buf->file, cl->buf->file_pos, cl->buf->file_last); ngx_debug_point(); return NGX_ERROR; } #endif size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->recycled) { flush = 1; } if (cl->buf->sync) { sync = 1; } if (cl->buf->last_buf) { last = 1; } } *ll = NULL; ngx_log_debug3(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream write filter: l:%ui f:%ui s:%O", last, flush, size); if (size == 0 && !(c->buffered & NGX_LOWLEVEL_BUFFERED) && !(last && c->need_last_buf)) { if (last || flush || sync) { for (cl = *out; cl; /* void */) { ln = cl; cl = cl->next; ngx_free_chain(c->pool, ln); } *out = NULL; c->buffered &= ~NGX_STREAM_WRITE_BUFFERED; return NGX_OK; } ngx_log_error(NGX_LOG_ALERT, c->log, 0, "the stream output chain is empty"); ngx_debug_point(); return NGX_ERROR; } chain = c->send_chain(c, *out, 0); ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream write filter %p", chain); if (chain == NGX_CHAIN_ERROR) { c->error = 1; return NGX_ERROR; } for (cl = *out; cl && cl != chain; /* void */) { ln = cl; cl = cl->next; ngx_free_chain(c->pool, ln); } *out = chain; if (chain) { if (c->shared) { ngx_log_error(NGX_LOG_ALERT, c->log, 0, "shared connection is busy"); return NGX_ERROR; } c->buffered |= NGX_STREAM_WRITE_BUFFERED; return NGX_AGAIN; } c->buffered &= ~NGX_STREAM_WRITE_BUFFERED; if (c->buffered & NGX_LOWLEVEL_BUFFERED) { return NGX_AGAIN; } return NGX_OK; } static ngx_int_t ngx_stream_write_filter_init(ngx_conf_t *cf) { ngx_stream_top_filter = ngx_stream_write_filter; return NGX_OK; }