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Diffstat (limited to '')
-rwxr-xr-x | tests/tail-2/inotify-rotate-resources.sh | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/tests/tail-2/inotify-rotate-resources.sh b/tests/tail-2/inotify-rotate-resources.sh new file mode 100755 index 0000000..b532609 --- /dev/null +++ b/tests/tail-2/inotify-rotate-resources.sh @@ -0,0 +1,108 @@ +#!/bin/sh +# ensure that tail -F doesn't leak inotify resources + +# Copyright (C) 2015-2018 Free Software Foundation, Inc. + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <https://www.gnu.org/licenses/>. + +. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src +print_ver_ tail + +# Inotify not used on remote file systems +require_local_dir_ + +grep '^#define HAVE_INOTIFY 1' "$CONFIG_HEADER" >/dev/null \ + || skip_ 'inotify required' + +require_strace_ 'inotify_add_watch,inotify_rm_watch' + +check_tail_output() +{ + local delay="$1" + grep "$tail_re" out > /dev/null || + { sleep $delay; return 1; } +} + +# Wait up to 25.5 seconds for grep REGEXP 'out' to succeed. +grep_timeout() { tail_re="$1" retry_delay_ check_tail_output .1 8; } + +check_strace() +{ + local delay="$1" + grep "$strace_re" strace.out > /dev/null || + { sleep $delay; return 1; } +} + +cleanup_fail() +{ + cat out + warn_ $1 + fail=1 +} + +# Terminate any background tail process +cleanup_() { kill $pid 2>/dev/null && wait $pid; } + +fastpoll='-s.1 --max-unchanged-stats=1' + +touch k || framework_failure_ + +# Note the timeout guard isn't strictly necessary here, +# however without it strace will ignore SIGTERM. +# strace does always honor SIGTERM with the -I2 option, +# though that's not available on RHEL6 for example. +timeout 180 strace -e inotify_add_watch,inotify_rm_watch -o strace.out \ + tail -F $fastpoll k >> out 2>&1 & pid=$! + +reverted_to_polling_=0 +for i in $(seq 2); do + echo $i + + echo 'tailed' > k; + + # Wait for watch on (new) file + strace_re='inotify_add_watch.*MODIFY' retry_delay_ check_strace .1 8 || + no_watch_=1 + + # Assume this is not because we're leaking + # (resources may already be depleted) + # The explicit check for inotify_rm_watch should confirm that. + grep -F 'reverting to polling' out >/dev/null && skip_ 'inotify unused' + + # Otherwise failure is unknown + test "$no_watch_" && { cat out; framework_failure_ 'no inotify_add_watch'; } + + mv k k.tmp + # wait for tail to detect the rename + grep_timeout 'inaccessible' || + { cleanup_fail 'failed to detect rename'; break; } + + # Note we strace here rather than consuming all available watches + # to be more efficient, but more importantly avoid depleting resources. + # Note also available resources can currently be tuned with: + # sudo sysctl -w fs.inotify.max_user_watches=$smallish_number + # However that impacts all processes for the current user, and also + # may not be supported in future, instead being auto scaled to RAM + # like the Linux epoll resources were. + if test "$i" -gt 1; then + strace_re='inotify_rm_watch' retry_delay_ check_strace .1 8 || + { cleanup_fail 'failed to find inotify_rm_watch syscall'; break; } + fi + + >out && >strace.out || framework_failure_ 'failed to reset output files' +done + +cleanup_ + +Exit $fail |