12588 Commits

Author SHA1 Message Date
Christopher Faulet
49531e8471 BUG/MINOR; resolvers: Ignore DNS resolution for expired SRV item
If no ADD item is found for a SRV item in a SRV response, a DNS resolution
is triggered. When it succeeds, we must be sure the SRV item is still
alive. Otherwise the DNS resolution must be ignored.

This patch depends on the commit "MINOR: resolvers: Move last_seen time of
an ADD into its corresponding SRV item". Both must be backported as far as
2.2.
2021-03-12 17:41:28 +01:00
Baptiste Assmann
6a8d11dc80 MINOR: resolvers: new function find_srvrq_answer_record()
This function search for a SRV answer item associated to a requester
whose type is server.
This is mainly useful to "link" a server to its SRV record when no
additional record were found to configure the IP address.

This patch is required by a bug fix.
2021-03-12 17:41:28 +01:00
Christopher Faulet
77f860699c BUG/MEDIUM: resolvers: Fix the loop looking for an existing ADD item
For each ADD item found in a SRV response, we try to find a corresponding
ADD item already attached to an existing SRV item. If found, the ADD
last_seen time is updated, otherwise we try to find a SRV item with no ADD
to attached the new one.

However, the loop is buggy. Instead of comparing 2 ADD items, it compares
the new ADD item with the SRV item. Because of this bug, we are unable to
renew last_seen time of existing ADD.

This patch must be backported as far as 2.2.
2021-03-12 17:41:24 +01:00
Christopher Faulet
ab177ac1f3 BUG/MEDIUM: resolvers: Don't set an address-less server as UP
when a server status is updated based on a SRV item, it is always set to UP,
regardless it has an IP address defined or not. For instance, if only a SRV
item is received, with no additional record, only the server hostname is
defined. We must wait to have an IP address to set the server as UP.

This patch must be backported as far as 2.2.
2021-03-12 16:43:37 +01:00
Christopher Faulet
bca680ba90 BUG/MINOR: resolvers: Unlink DNS resolution to set RMAINT on SRV resolution
When a server is set in RMAINT becaues of a SRV resolution failure, the
server DNS resolution, if any, must be unlink first. It is mandatory to
handle the change in the context of a SRV resolution.

This patch must be backported as far as 2.2.
2021-03-12 16:43:37 +01:00
Christopher Faulet
5130c21fbb BUG/MINOR: resolvers: Reset server address on DNS error only on status change
When a DNS resolution error is detected, in snr_resolution_error_cb(), the
server address must be reset only if the server status has changed. It this
case, it means the server is set to RMAINT. Thus the server address may by
reset.

This patch fixes a bug introduced by commit d127ffa9f ("BUG/MEDIUM:
resolvers: Reset address for unresolved servers"). It must be backported as
far as 2.0.
2021-03-12 16:43:37 +01:00
Christopher Faulet
bd0227c109 BUG/MINOR: resolvers: Consider server to have no IP on DNS resolution error
When an error is received for a DNS resolution, for instance a NXDOMAIN
error, the server must be considered to have no address when its status is
updated, not the opposite.

Concretly, because this parameter is not used on error path in
snr_update_srv_status(), there is no impact.

This patch must be backported as far as 1.8.
2021-03-12 16:43:37 +01:00
Christopher Faulet
5037c06d91 Revert "BUG/MINOR: resolvers: Only renew TTL for SRV records with an additional record"
This reverts commit a331a1e8eb2ad4750711a477ca3e22d940495faf.

This commit fixes a real bug, but it also reveals some hidden bugs, mostly
because of some design issues. Thus, in itself, it create more problem than
it solves. So revert it for now. All known bugs will be addressed in next
commits.

This patch should be backported as far as 2.2.
2021-03-12 16:43:37 +01:00
Willy Tarreau
736adef511 BUG/MINOR: cfgparse/server: increment the extra keyword counter one at a time
This was introduced in previous commit 49c2b45c1 ("MINOR: cfgparse/server:
try to fix spelling mistakes on server lines"), the loop was changed but
the increment left. No backport is needed.
2021-03-12 14:47:10 +01:00
Willy Tarreau
db67b0ed79 MINOR: tcp-rules: suggest approaching action names on mismatch
This adds support for action_suggest() in tcp-request and tcp-response
rules so as to propose the closest match in case of misspelling.
2021-03-12 14:13:21 +01:00
Willy Tarreau
49bf7beb14 MINOR: http-rules: suggest approaching action names on mismatch
This adds support for action_suggest() in http-request, http-response
and http-after-response rulesets. For example:

   parsing [/dev/stdin:2]: 'http-request' expects (...), but got 'del-hdr'. Did you mean 'del-header' maybe ?
2021-03-12 14:13:21 +01:00
Willy Tarreau
99eb2cc1cc MINOR: actions: add a function to suggest an action ressembling a given word
action_suggest() will return a pointer to an action whose keyword more or
less ressembles the passed argument. It also accepts to be more tolerant
against prefixes (since actions taking arguments are handled as prefixes).
This will be used to suggest approaching words.
2021-03-12 14:13:21 +01:00
Willy Tarreau
433b05fa64 MINOR: cfgparse/bind: suggest correct spelling for unknown bind keywords
Just like with the server keywords, now's the turn of "bind" keywords.
The difference is that 100% of the bind keywords are registered, thus
we do not need the list of extra keywords.

There are multiple bind line parsers today, all were updated:
  - peers
  - log
  - dgram-bind
  - cli

$ printf "listen f\nbind :8000 tcut\n" | ./haproxy -c -f /dev/stdin
[NOTICE] 070/101358 (25146) : haproxy version is 2.4-dev11-7b8787-26
[NOTICE] 070/101358 (25146) : path to executable is ./haproxy
[ALERT] 070/101358 (25146) : parsing [/dev/stdin:2] : 'bind :8000' unknown keyword 'tcut'; did you mean 'tcp-ut' maybe ?
[ALERT] 070/101358 (25146) : Error(s) found in configuration file : /dev/stdin
[ALERT] 070/101358 (25146) : Fatal errors found in configuration.
2021-03-12 14:13:21 +01:00
Willy Tarreau
49c2b45c1d MINOR: cfgparse/server: try to fix spelling mistakes on server lines
Let's apply the fuzzy match to server keywords so that we can avoid
dumping the huge list of supported keywords each time there is a spelling
mistake, and suggest proper spelling instead:

  $ printf "listen f\nserver s 0 sendpx-v2\n" | ./haproxy -c -f /dev/stdin
  [NOTICE] 070/095718 (24152) : haproxy version is 2.4-dev11-caa6e3-25
  [NOTICE] 070/095718 (24152) : path to executable is ./haproxy
  [ALERT] 070/095718 (24152) : parsing [/dev/stdin:2] : 'server s' unknown keyword 'sendpx-v2'; did you mean 'send-proxy-v2' maybe ?
  [ALERT] 070/095718 (24152) : Error(s) found in configuration file : /dev/stdin
  [ALERT] 070/095718 (24152) : Fatal errors found in configuration.
2021-03-12 14:13:21 +01:00
Willy Tarreau
a0e8eb8caa MINOR: cfgparse: suggest correct spelling for unknown words in global section
The global section also knows a large number of keywords that are not
referenced in any list, so this needed them to be specifically listed.
It becomes particularly handy now because some tunables are never easy
to remember, but now it works remarkably well:

  $ printf "global\nsched.queue_depth\n" | ./haproxy -c -f /dev/stdin
  [NOTICE] 070/093007 (23457) : haproxy version is 2.4-dev11-dd8ee5-24
  [NOTICE] 070/093007 (23457) : path to executable is ./haproxy
  [ALERT] 070/093007 (23457) : parsing [/dev/stdin:2] : unknown keyword 'sched.queue_depth' in 'global' section; did you mean 'tune.runqueue-depth' maybe ?
  [ALERT] 070/093007 (23457) : Error(s) found in configuration file : /dev/stdin
  [ALERT] 070/093007 (23457) : Fatal errors found in configuration.
2021-03-12 14:13:21 +01:00
Willy Tarreau
c0ff679481 MINOR: cfgparse: suggest correct spelling for unknown words in proxy sections
Let's start by the largest keyword list, the listeners. Many keywords were
still not part of a list, so a common_kw_list array was added to list the
not enumerated ones. Now for example, typing "tmout" properly suggests
"timeout":

  $ printf "frontend f\ntmout client 10s\n" | ./haproxy -c -f /dev/stdin
  [NOTICE] 070/091355 (22545) : haproxy version is 2.4-dev11-3b728a-21
  [NOTICE] 070/091355 (22545) : path to executable is ./haproxy
  [ALERT] 070/091355 (22545) : parsing [/dev/stdin:2] : unknown keyword 'tmout' in 'frontend' section; did you mean 'timeout' maybe ?
  [ALERT] 070/091355 (22545) : Error(s) found in configuration file : /dev/stdin
  [ALERT] 070/091355 (22545) : Fatal errors found in configuration.
2021-03-12 14:13:21 +01:00
Willy Tarreau
e2afcc4509 MINOR: cfgparse: add cfg_find_best_match() to suggest an existing word
Instead of just reporting "unknown keyword", let's provide a function which
will look through a list of registered keywords for a similar-looking word
to the one that wasn't matched. This will help callers suggest correct
spelling. Also, given that a large part of the config parser still relies
on a long chain of strcmp(), we'll need to be able to pass extra candidates.
Thus the function supports an optional extra list for this purpose.
2021-03-12 14:13:21 +01:00
Willy Tarreau
ba2c4459a5 MINOR: tools: add simple word fingerprinting to find similar-looking words
This introduces two functions, one which creates a fingerprint of a word,
and one which computes a distance between two words fingerprints. The
fingerprint is made by counting the transitions between one character and
another one. Here we consider the 26 alphabetic letters regardless of
their case, then any digit as a digit, and anything else as "other". We
also consider the first and last locations as transitions from begin to
first char, and last char to end. The distance is simply the sum of the
squares of the differences between two fingerprints. This way, doubling/
missing a letter has the same cost, however some repeated transitions
such as "e"->"r" like in "server" are very unlikely to match against
situations where they do not exist. This is a naive approach but it seems
to work sufficiently well for now. It may be refined in the future if
needed.
2021-03-12 14:13:21 +01:00
Willy Tarreau
25809999fe CLEANUP: http-rules: remove the unexpected comma before the list of action keywords
The error message for http-request and http-response starts with a comma
that very likely is a leftover from a previous list construct. Let's remove
it: "'http-request' expects , 'wait-for-handshake', 'use-service' ...".
2021-03-12 14:13:20 +01:00
Willy Tarreau
3d1d178933 CLEANUP: vars: make the error message clearer on missing arguments for set-var
The error message after "http-response set-var" isn't very clear:

  [ALERT] 070/115043 (30526) : parsing [/dev/stdin:2] : error detected in proxy 'f' while parsing 'http-response set-var' rule : invalid variable 'set-var'. Expects 'set-var(<var-name>)' or 'unset-var(<var-name>)'.

Let's change it to this instead:

  [ALERT] 070/115608 (30799) : parsing [/dev/stdin:2] : error detected in proxy 'f' while parsing 'http-response set-var' rule : invalid or incomplete action 'set-var'. Expects 'set-var(<var-name>)' or 'unset-var(<var-name>)'.

With a wrong action name, it also works better (it's handled as a prefix
due to the opening parenthesis):

  [ALERT] 070/115608 (30799) : parsing [/dev/stdin:2] : error detected in proxy 'f' while parsing 'http-response set-varxxx' rule : invalid or incomplete action 'set-varxxx'. Expects 'set-var(<var-name>)' or 'unset-var(<var-name>)'.
2021-03-12 14:13:20 +01:00
Willy Tarreau
72d012fbd9 CLEANUP: tcp-rules: add missing actions in the tcp-request error message
The tcp-request error message only mentions "accept", "reject" and
track-sc*, but there are a few other ones that were missing, so let's
add them.

This could be backported, though it's not likely that it will help anyone
with an existing config.
2021-03-12 14:13:20 +01:00
Willy Tarreau
47a30c456c BUG/MINOR: server-state: use the argument, not the global state
The refactoring in commit 131b07be3 ("MEDIUM: server: Refactor
apply_server_state() to make it more readable") also had a copy-paste
error resulting in using global.server_state_file instead of the
function's argument, which easily crashes with a conf having a
state file in a backend and no global state file.

In addition, let's simplify the code and get rid of strcpy() which
almost certainly will break the build on OpenBSD.

This was introduced in 2.4-dev10, no backport is needed.
2021-03-12 14:13:07 +01:00
Willy Tarreau
6d4173e622 BUG/MINOR: server-state: properly handle the case where the base is not set
The refactoring in commit 131b07be3 ("MEDIUM: server: Refactor
apply_server_state() to make it more readable") made the global
server_state_base be dereferenced before being checked, resulting
in a crash on certain files.

This happened in 2.4-dev10, no backport is needed.
2021-03-12 13:57:19 +01:00
Christopher Faulet
cd03be73d5 BUG/MINOR: tcpcheck: Fix double free on error path when parsing tcp/http-check
When a "tcp-check" or a "http-check" rule is parsed, we try to get the
previous rule in the ruleset to get its index. We must take care to reset
the pointer on this rule in case an error is triggered later on the
parsing. Otherwise, the same rule may be released twice. For instance, it
happens with such line :

    http-check meth GET uri / ## note there is no "send" parameter

This patch must be backported as far as 2.2.
2021-03-12 13:17:46 +01:00
Christopher Faulet
24ec943427 BUG/MINOR: tcpcheck: Update .health threshold of agent inside an agent-check
If an agent-check is configured for a server, When the response is parsed,
the .health threshold of the agent must be updated on up/down/stopped/fail
command and not the threshold of the health-check. Otherwise, the
agent-check will compete with the health-check and may mark a DOWN server as
UP.

This patch should fix the issue #1176. It must be backported as far as 2.2.
2021-03-12 09:25:45 +01:00
Christopher Faulet
5647fbacdf BUG/MEDIUM: filters: Set CF_FL_ANALYZE on channels when filters are attached
CF_FL_ANALYZE flag is used to know a channel is filtered. It is important to
synchronize request and response channels when the filtering ends.

However, it is possible to call all request analyzers before starting the
filtering on the response channel. This means flt_end_analyze() may be
called for the request channel before flt_start_analyze() on the response
channel. Thus because CF_FL_ANALYZE flag is not set on the response channel,
we consider the filtering is finished on both sides. The consequence is that
flt_end_analyze() is not called for the response and backend filters are
unregistered before their execution on the response channel.

It is possible to encounter this bug on TCP frontend or CONNECT request on
HTTP frontend if the client shutdown is reveiced with the first read.

To fix this bug, CF_FL_ANALYZE is set when filters are attached to the
stream. It means, on the request channel when the stream is created, in
flt_stream_start(). And on both channels when the backend is set, in
flt_set_stream_backend().

This patch must be backported as far as 1.7.
2021-03-12 09:25:45 +01:00
Emeric Brun
362d25e507 BUG/MEDIUM: stick-tables: fix ref counter in table entry using multiple http tracksc.
Setting multiple http-request track-scX rules generates entries
which never expires.

If there was already an entry registered by a previous http rule
'stream_track_stkctr(&s->stkctr[rule->action], t, ts)' didn't
register the new 'ts' into the stkctr. And function is left
with no reference on 'ts' whereas refcount had been increased
by the '_get_entry'

The patch applies the same policy as the one showed on tcp track
rules and if there is successive rules the track counter keep the
first entry registered in the counter and nothing more is computed.

After validation this should be backported in all versions.
2021-03-11 14:14:44 +01:00
Willy Tarreau
060a761248 OPTIM: task: automatically adjust the default runqueue-depth to the threads
The recent default runqueue size reduction appeared to have significantly
lowered performance on low-thread count configs. Testing various values
runqueue values on different workloads under thread counts ranging from
1 to 64, it appeared that lower values are more optimal for high thread
counts and conversely. It could even be drawn that the optimal value for
various workloads sits around 280/sqrt(nbthread), and probably has to do
with both the L3 cache usage and how to optimally interlace the threads'
activity to minimize contention. This is much easier to optimally
configure, so let's do this by default now.
2021-03-10 11:15:34 +01:00
Willy Tarreau
1691ba3693 MINOR: task: give the scheduler a bit more flexibility in the runqueue size
Instead of setting a hard-limit on runqueue-depth and keeping it short
to maintain fairness, let's allow the scheduler to automatically cut
the existing one in two equal halves if its size is between the configured
size and its double. This will allow to increase the default value while
keeping a low latency.
2021-03-10 11:15:34 +01:00
Willy Tarreau
4c48edba4f BUG/MEDIUM: ssl: properly remove the TASK_HEAVY flag at end of handshake
Emeric found that SSL+keepalive traffic had dropped quite a bit in the
recent changes, which could be bisected to recent commit 9205ab31d
("MINOR: ssl: mark the SSL handshake tasklet as heavy"). Indeed, a
first incarnation of this commit made use of the TASK_SELF_WAKING
flag but the last version directly used TASK_HEAVY, but it would still
continue to remove the already absent TASK_SELF_WAKING one instead of
TASK_HEAVY. As such, the SSL traffic remained processed with low
granularity.

No backport is needed as this is only 2.4.
2021-03-09 17:58:02 +01:00
Willy Tarreau
5a1c7280a9 CLEANUP: config: also address the cfg_keyword API change in the compression code
The tests were made on slz and the zlib parsers for memlevel and windowsize
managed to escape the change made by commit 018251667 ("CLEANUP: config: make
the cfg_keyword parsers take a const for the defproxy"). This is now fixed.
2021-03-09 16:57:08 +01:00
Willy Tarreau
e89fae3a4e CLEANUP: stream: rename a few remaining occurrences of "stream *sess"
These are some leftovers from the ancient code where they were still
called sessions, but these areas in the code remain confusing due to
this naming. They were now called "strm" which will not even affect
indenting nor alignment.
2021-03-09 15:44:33 +01:00
William Lallemand
36119de182 BUG/MEDIUM: session: NULL dereference possible when accessing the listener
When implementing a client applet, a NULL dereference was encountered on
the error path which increment the counters.

Indeed, the counters incremented are the one in the listener which does
not exist in the case of client applets, so in sess->listener->counters,
listener is NULL.

This patch fixes the access to the listener structure when accessing
from a sesssion, most of the access are the counters in error paths.

Must be backported as far as 1.8.
2021-03-09 12:51:42 +01:00
Willy Tarreau
018251667e CLEANUP: config: make the cfg_keyword parsers take a const for the defproxy
The default proxy was passed as a variable to all parsers instead of a
const, which is not without risk, especially when some timeout parsers used
to make some int pointers point to the default values for comparisons. We
want to be certain that none of these parsers will modify the defaults
sections by accident, so it's important to mark this proxy as const.

This patch touches all occurrences found (89).
2021-03-09 10:09:43 +01:00
Willy Tarreau
b7e0c633e8 BUILD: task: fix build at -O0 with threads disabled
grq_total was incremented when picking tasks from the global run queue,
but this variable was not defined with threads disabled, and the code
was optimized away at -O2. No backport is needed.
2021-03-09 10:01:01 +01:00
Tim Duesterhus
56c176a780 CLEANUP: connection: Consistently use struct ist to process all TLV types
Instead of directly poking around within the `struct tlv tlv_packet` the actual
value will be consumed using a `struct ist`.
2021-03-09 09:24:32 +01:00
Tim Duesterhus
615f81eb5a MINOR: connection: Use a struct ist to store proxy_authority
This makes the code cleaner, because proxy_authority can be handled like
proxy_unique_id.
2021-03-09 09:24:32 +01:00
Tim Duesterhus
002bd77a6e CLEANUP: connection: Use istptr / istlen for proxy_unique_id
Don't access the ist's fields directly, use the helper functions instead.
2021-03-09 09:24:32 +01:00
Ilya Shipitsin
d7a988c14a CLEANUP: assorted typo fixes in the code and comments
This is 19th iteration of typo fixes
2021-03-05 21:22:47 +01:00
Amaury Denoyelle
249f0562cf BUG/MINOR: backend: fix condition for reuse on mode HTTP
This commit is a fix/complement to the following one :
08d87b3f49867440f66aee09173c84bf58cbc859
BUG/MEDIUM: backend: never reuse a connection for tcp mode

It fixes the check for the early insertion of backend connections in
the reuse lists if the backend mode is HTTP.

The impact of this bug seems limited because :
- in tcp mode, no insertion is done in the avail list as mux_pt does not
  support multiple streams.
- in http mode, muxes are also responsible to insert backend connections
  in lists in their detach functions. Prior to this fix the reuse rate
  could be slightly inferior.

It can be backported to 2.3.
2021-03-05 15:44:51 +01:00
Amaury Denoyelle
d7faa3d6e9 MINOR: backend: add a BUG_ON if conn mux NULL in connect_server
Currently, there seems to be no way to have the transport layer ready
but not the mux in the function connect_server. Add a BUG_ON to report
if this implicit condition is not true anymore.

This should fix coverity report from github issue #1120.
2021-03-05 15:27:41 +01:00
Willy Tarreau
d4e78d873c MINOR: server: move actconns to the per-thread structure
The actconns list creates massive contention on low server counts because
it's in fact a list of streams using a server, all threads compete on the
list's head and it's still possible to see some watchdog panics on 48
threads under extreme contention with 47 threads trying to add and one
thread trying to delete.

Moving this list per thread is trivial because it's only used by
srv_shutdown_streams(), which simply required to iterate over the list.

The field was renamed to "streams" as it's really a list of streams
rather than a list of connections.
2021-03-05 15:00:24 +01:00
Willy Tarreau
430bf4a483 MINOR: server: allocate a per-thread struct for the per-thread connections stuff
There are multiple per-thread lists in the listeners, which isn't the
most efficient in terms of cache, and doesn't easily allow to store all
the per-thread stuff.

Now we introduce an srv_per_thread structure which the servers will have an
array of, and place the idle/safe/avail conns tree heads into. Overall this
was a fairly mechanical change, and the array is now always initialized for
all servers since we'll put more stuff there. It's worth noting that the Lua
code still has to deal with its own deinit by itself despite being in a
global list, because its server is not dynamically allocated.
2021-03-05 15:00:24 +01:00
Willy Tarreau
4cdac166e0 MINOR: cfgparse: finish to set up servers outside of the proxy setup loop
Till now servers were only initialized as part of the proxy setup loop,
which doesn't cover peers, tcp log, dns, lua etc. Let's move this part
out of this loop and instead iterate over all registered servers. This
way we're certain to visit them all.

The patch looks big but it's just a move of a large block with the
corresponding reindent (as can be checked with diff -b). It relies
on the two previous ones ("MINOR: server: add a global list of all
known servers and" and "CLEANUP: lua: set a dummy file name and line
number on the dummy servers").
2021-03-05 15:00:24 +01:00
Willy Tarreau
198e92a8e5 MINOR: server: add a global list of all known servers
It's a real pain not to have access to the list of all registered servers,
because whenever there is a need to late adjust their configuration, only
those attached to regular proxies are seen, but not the peers, lua, logs
nor DNS.

What this patch does is that new_server() will automatically add the newly
created server to a global list, and it does so as well for the 1 or 2
statically allocated servers created for Lua. This way it will be possible
to iterate over all of them.
2021-03-05 15:00:24 +01:00
Willy Tarreau
0f143afe1b CLEANUP: lua: set a dummy file name and line number on the dummy servers
The "socket_tcp" and "socket_ssl" servers had no config file name nor
line number, but this is sometimes annoying during debugging or later
in error messages, while all other places using new_server() or
parse_server() make sure to have a valid file:line set. Let's set
something to address this.
2021-03-05 15:00:24 +01:00
Willy Tarreau
5b5974104f CLEANUP: sockpair: silence a coverity check about fcntl()
This is about coverity complaining that we didn't check the fcntl call
which can't fail, let's consume it. This is issue #1158.
2021-03-05 14:33:13 +01:00
Willy Tarreau
4149168255 MEDIUM: ssl: implement xprt_set_used and xprt_set_idle to relax context checks
Currently the SSL layer checks the validity of its tasklet's context just
in case it would have been stolen, had the connection been idle. Now it
will be able to be notified by the mux when this situation happens so as
not to have to grab the idle connection lock on each pass. This reuses the
TASK_F_USR1 flag just as the muxes do.
2021-03-05 08:30:08 +01:00
Willy Tarreau
4f8cd4397f MINOR: xprt: add new xprt_set_idle and xprt_set_used methods
These functions are used on the mux layer to indicate that the connection
is becoming idle and that the xprt ought to be careful before checking the
context or that it's not idle anymore and that the context is safe. The
purpose is to allow a mux which is going to release a connection to tell
the xprt to be careful when touching it. At the moment, the xprt are
always careful and that's costly so we want to have the ability to relax
this a bit.

No xprt layer uses this yet.
2021-03-05 08:30:08 +01:00
Willy Tarreau
e388f2fbca MEDIUM: muxes: mark idle conns tasklets with TASK_F_USR1
The muxes are touching the idle_conns_lock all the time now because
they need to be careful that no other thread has stolen their tasklet's
context.

This patch changes this a little bit by setting the TASK_F_USR1 flag on
the tasklet before marking a connection idle, and removing it once it's
not idle anymore. Thanks to this we have the guarantee that a tasklet
without this flag cannot be present in an idle list and does not need
to go through this costly lock. This is especially true for front
connections.
2021-03-05 08:30:08 +01:00