user/dev discussion of public-inbox itself
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From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Subject: [PATCH 35/57] ds: deal better with FS-related errors IO buffers
Date: Mon, 24 Jun 2019 02:52:36 +0000
Message-ID: <20190624025258.25592-36-e@80x24.org> (raw)
In-Reply-To: <20190624025258.25592-1-e@80x24.org>

Instead of ENOMEM (or fragmentation/swap storms), using tempfile
buffers opens us up to filesystem and storage-related errors
(e.g. ENOSPC, EFBIG, EIO, EROFS).  Log these errors, drop the
particular client, and try to limp by with whateve we have left.
---
 lib/PublicInbox/DS.pm | 42 +++++++++++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/lib/PublicInbox/DS.pm b/lib/PublicInbox/DS.pm
index 486af40e..1a1ef7d3 100644
--- a/lib/PublicInbox/DS.pm
+++ b/lib/PublicInbox/DS.pm
@@ -33,7 +33,7 @@ use fields ('sock',              # underlying socket
             );
 
 use Errno  qw(EAGAIN EINVAL);
-use Carp   qw(croak confess);
+use Carp   qw(croak confess carp);
 use File::Temp qw(tempfile);
 
 our $HAVE_KQUEUE = eval { require IO::KQueue; IO::KQueue->import; 1 };
@@ -482,18 +482,27 @@ sub do_read ($$$$) {
     $! == EAGAIN ? $self->watch_in1 : $self->close;
 }
 
+# drop the socket if we hit unrecoverable errors on our system which
+# require BOFH attention: ENOSPC, EFBIG, EIO, EMFILE, ENFILE...
+sub drop {
+    my $self = shift;
+    carp(@_);
+    $self->close;
+}
+
 # n.b.: use ->write/->read for this buffer to allow compatibility with
 # PerlIO::mmap or PerlIO::scalar if needed
-sub tmpbuf ($$) {
-    my ($bref, $off) = @_;
+sub tmpio ($$$) {
+    my ($self, $bref, $off) = @_;
     # open(my $fh, '+>>', undef) doesn't set O_APPEND
-    my ($fh, $path) = tempfile('wbuf-XXXXXXX', TMPDIR => 1);
-    open $fh, '+>>', $path or die "open: $!";
+    my ($fh, $path) = eval { tempfile('wbuf-XXXXXXX', TMPDIR => 1) };
+    $fh or return drop($self, "tempfile: $@");
+    open($fh, '+>>', $path) or return drop($self, "open: $!");
     $fh->autoflush(1);
-    unlink $path;
-    my $to_write = bytes::length($$bref) - $off;
-    $fh->write($$bref, $to_write, $off) or die "write ($to_write): $!";
-    $fh;
+    unlink($path) or return drop($self, "unlink: $!");
+    my $len = bytes::length($$bref) - $off;
+    $fh->write($$bref, $len, $off) or return drop($self, "write ($len): $!");
+    $fh
 }
 
 =head2 C<< $obj->write( $data ) >>
@@ -523,12 +532,10 @@ sub write {
         } else {
             my $last = $wbuf->[-1];
             if (ref($last) eq 'GLOB') { # append to tmp file buffer
-                unless ($last->print($$bref)) {
-                    warn "error buffering: $!";
-                    return $self->close;
-                }
+                $last->print($$bref) or return drop($self, "print: $!");
             } else {
-                push @$wbuf, tmpbuf($bref, 0);
+                my $tmpio = tmpio($self, $bref, 0) or return 0;
+                push @$wbuf, $tmpio;
             }
         }
         return 0;
@@ -546,7 +553,8 @@ sub write {
         } else {
             return $self->close;
         }
-        $self->{wbuf} = [ tmpbuf($bref, $written) ];
+        my $tmpio = tmpio($self, $bref, $written) or return 0;
+        $self->{wbuf} = [ $tmpio ];
         watch($self, EPOLLOUT|EPOLLONESHOT);
         return 0;
     }
@@ -563,9 +571,9 @@ sub msg_more ($$) {
         if (defined $n) {
             my $nlen = bytes::length($_[1]) - $n;
             return 1 if $nlen == 0; # all done!
-
             # queue up the unwritten substring:
-            $self->{wbuf} = [ tmpbuf(\($_[1]), $n) ];
+            my $tmpio = tmpio($self, \($_[1]), $n) or return 0;
+            $self->{wbuf} = [ $tmpio ];
             watch($self, EPOLLOUT|EPOLLONESHOT);
             return 0;
         }
-- 
EW


  parent reply index

Thread overview: 61+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-24  2:52 [PATCH 00/57] ds: shrink, TLS support, buffer writes to FS Eric Wong
2019-06-24  2:52 ` [PATCH 01/57] ds: get rid of {closed} field Eric Wong
2019-06-24  2:52 ` [PATCH 02/57] ds: get rid of more unused debug instance methods Eric Wong
2019-06-24  2:52 ` [PATCH 03/57] ds: use and export monotonic now() Eric Wong
2019-06-24  2:52 ` [PATCH 04/57] AddTimer: avoid clock_gettime for the '0' case Eric Wong
2019-06-24  2:52 ` [PATCH 05/57] ds: get rid of on_incomplete_write wrapper Eric Wong
2019-06-24  2:52 ` [PATCH 06/57] ds: lazy initialize wbuf_off Eric Wong
2019-06-24  2:52 ` [PATCH 07/57] ds: split out from ->flush_write and ->write Eric Wong
2019-06-24  2:52 ` [PATCH 08/57] ds: lazy-initialize wbuf Eric Wong
2019-06-24  2:52 ` [PATCH 09/57] ds: don't pass `events' arg to EPOLL_CTL_DEL Eric Wong
2019-06-24  2:52 ` [PATCH 10/57] ds: remove support for DS->write(undef) Eric Wong
2019-06-24  2:52 ` [PATCH 11/57] http: favor DS->write(strref) when reasonable Eric Wong
2019-06-24  2:52 ` [PATCH 12/57] ds: share send(..., MSG_MORE) logic Eric Wong
2019-06-24  2:52 ` [PATCH 13/57] ds: switch write buffering to use a tempfile Eric Wong
2019-06-24  2:52 ` [PATCH 14/57] ds: get rid of redundant and unnecessary POLL* constants Eric Wong
2019-06-24  2:52 ` [PATCH 15/57] syscall: get rid of unused EPOLL* constants Eric Wong
2019-06-24  2:52 ` [PATCH 16/57] syscall: get rid of unnecessary uname local vars Eric Wong
2019-06-24  2:52 ` [PATCH 17/57] ds: set event flags directly at initialization Eric Wong
2019-06-24  2:52 ` [PATCH 18/57] ds: import IO::KQueue namespace Eric Wong
2019-06-24  2:52 ` [PATCH 19/57] ds: share watch_chg between watch_read/watch_write Eric Wong
2019-06-24  2:52 ` [PATCH 20/57] ds: remove IO::Poll support (for now) Eric Wong
2019-06-24  2:52 ` [PATCH 21/57] ds: get rid of event_watch field Eric Wong
2019-06-24  2:52 ` [PATCH 22/57] httpd/async: remove EINTR check Eric Wong
2019-06-24  2:52 ` [PATCH 23/57] spawn: remove `Blocking' flag handling Eric Wong
2019-06-24  2:52 ` [PATCH 24/57] qspawn: describe where `$rpipe' come from Eric Wong
2019-06-24  2:52 ` [PATCH 25/57] http|nntp: favor "$! == EFOO" over $!{EFOO} checks Eric Wong
2019-06-24  2:52 ` [PATCH 26/57] ds: favor `delete' over assigning fields to `undef' Eric Wong
2019-06-24  2:52 ` [PATCH 27/57] http: don't pass extra args to PublicInbox::DS::close Eric Wong
2019-06-24  2:52 ` [PATCH 28/57] ds: pass $self to code references Eric Wong
2019-06-24  2:52 ` [PATCH 29/57] evcleanup: replace _run_asap with `event_step' callback Eric Wong
2019-06-24  2:52 ` [PATCH 30/57] ds: remove pointless exit calls Eric Wong
2019-06-24  2:52 ` [PATCH 31/57] http|nntp: be explicit about bytes::length on rbuf Eric Wong
2019-06-24  2:52 ` [PATCH 32/57] ds: hoist out do_read from NNTP and HTTP Eric Wong
2019-06-24  2:52 ` [PATCH 33/57] nntp: simplify re-arming/requeue logic Eric Wong
2019-06-24  2:52 ` [PATCH 34/57] allow use of PerlIO layers for filesystem writes Eric Wong
2019-06-24  2:52 ` Eric Wong [this message]
2019-06-24  2:52 ` [PATCH 36/57] nntp: wait for writability before sending greeting Eric Wong
2019-06-24  2:52 ` [PATCH 37/57] nntp: NNTPS and NNTP+STARTTLS working Eric Wong
2019-06-24  2:52 ` [PATCH 38/57] certs/create-certs.perl: fix cert validity on 32-bit Eric Wong
2019-06-24  2:52 ` [PATCH 39/57] daemon: map inherited sockets to well-known schemes Eric Wong
2019-06-24  2:52 ` [PATCH 40/57] ds|nntp: use CORE::close on socket Eric Wong
2019-06-24  2:52 ` [PATCH 41/57] nntp: call SSL_shutdown in normal cases Eric Wong
2019-06-24  2:52 ` [PATCH 42/57] t/nntpd-tls: slow client connection test Eric Wong
2019-06-24  2:52 ` [PATCH 43/57] daemon: use SSL_MODE_RELEASE_BUFFERS Eric Wong
2019-06-24  2:52 ` [PATCH 44/57] ds: allow ->write callbacks to syswrite directly Eric Wong
2019-06-24  2:52 ` [PATCH 45/57] nntp: reduce allocations for greeting Eric Wong
2019-06-24  2:52 ` [PATCH 46/57] ds: always use EV_ADD with EV_SET Eric Wong
2019-06-24  2:52 ` [PATCH 47/57] nntp: simplify long response logic and fix nesting Eric Wong
2019-06-24  2:52 ` [PATCH 48/57] ds: flush_write runs ->write callbacks even if closed Eric Wong
2019-06-24  2:52 ` [PATCH 49/57] nntp: lazily allocate and stash rbuf Eric Wong
2019-06-24  2:52 ` [PATCH 50/57] ci: require IO::KQueue on FreeBSD, for now Eric Wong
2019-06-24  2:52 ` [PATCH 51/57] nntp: send greeting immediately for plain sockets Eric Wong
2019-06-24  2:52 ` [PATCH 52/57] daemon: set TCP_DEFER_ACCEPT on everything but NNTP Eric Wong
2019-06-24  2:52 ` [PATCH 53/57] daemon: use FreeBSD accept filters on non-NNTP Eric Wong
2019-06-24  2:52 ` [PATCH 54/57] ds: split out IO::KQueue-specific code Eric Wong
2019-06-24  5:24   ` Eric Wong
2019-06-24  2:52 ` [PATCH 55/57] ds: reimplement IO::Poll support to look like epoll Eric Wong
2019-06-24  2:52 ` [PATCH 56/57] Revert "ci: require IO::KQueue on FreeBSD, for now" Eric Wong
2019-06-24  2:52 ` [PATCH 57/57] ds: reduce overhead of tempfile creation Eric Wong
2019-06-24  5:25 ` [PATCH 58/57] Makefile: skip DSKQXS in global syntax check Eric Wong
2019-06-24 18:28 ` [PATCH 59/57] ds: ->write must not clobber empty wbuf array Eric Wong

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