* src/tail.c (tail_forever_inotify): Handle the case where
tail --follow=name with inotify, is not able to add a watch on
a specified directory. This may happen due to inotify resource
limits or if the directory is currently missing or inaccessible.
In all these cases, revert to polling which will try to reopen
the file later. Note inotify returns ENOSPC when it runs out
of resources, and instead we report a particular error message,
lest users think one of their file systems is full.
(main): Document another caveat with using inotify, where we
currently don't recheck directories recreated after the
initial watch is setup.
* tests/tail-2/F-vs-rename: Fix the endless loop triggered by
the above issue.
* tests/tail-2/inotify-hash-abuse: Likewise.
* tests/tail-2/wait: Don't fail in the resource exhaustion case.
* tests/tail-2/F-vs-missing: A new test for this failure mode
which was until now just triggered on older buggy linux kernels
which returned ENOSPC constantly from inotify_add_watch().
* NEWS: Mention the fix.
* tests/init.cfg: Introduce a retry_delay_() function to
repeatedly call a test function that requires a delay.
This delay can now be shorter for the common case on fast
systems, but will double until a configurable limit it reached
before failing on slower systems.
* tests/dd/reblock: Use retry_delay_.
* tests/misc/cat-buf: Likewise.
* tests/misc/stdbuf: Likewise.
* tests/tail-2/F-vs-rename: Likewise.
* tests/tail-2/flush-initial: Likewise.
* tests/tail-2/tail-n0f: Likewise.
* tests/tail-2/wait: Likewise.
* test/dd/misc: Comment that delay is needed to trigger failure.
Prompted by the continuous integration build failure at:
http://hydra.nixos.org/build/277485
* tests/misc/timeout: Set all expected timeouts to 1s and all
unexpected timeouts to 10s. In this way, tests normally proceed
quickly but may delay up to 10s before reporting failures.
* tests/ls/infloop: Likewise.
* tests/tail-2/pid: Likewise.
* tests/tail-2/pipe-f: Likewise.
* tests/tail-2/wait: Likewise.
* tests/dd/skip-seek-past-dev: Likewise.
Run this command to remove the factored-out "fail=0" lines.
perl -ni -e '/^fail=0$/ or print' $(g grep -l '^fail=0$')
* tests/test-lib.sh: Initialize fail=0 here, not in 300+ scripts.
* tests/...: nearly all bourne shell scripts
Suggested by Eric Blake.
* src/tail.c (main): Add an undocumented ---disable-inotify option
to allow disabling inotify.
* tests/tail-2/pid: Run test in both normal and "disable_inotify" modes.
* tests/tail-2/tail-n0f: Likewise.
* tests/tail-2/wait: Likewise.
* tests/tail-2/append-only: Likewise.
* tests/tail-2/wait: Increase the file name recheck frequency to
fix a failure on systems without inotify and a file timestamp precision
of 1 second (like GNU/kFreeBSD).
* tests/tail-2/wait: Silently skip a portion of the test
when running as root, rather than failing the whole test.
This regression was introduced with commit 84b5844d, 2009-09-03,
"tests: simplify and fix a race in 2 tail --follow tests".
* tests/tail-2/pid: Use the timeout command to determine process
longevity, rather than querying /proc/$pid/status.
The latter was racy in any case when inotify is used, as then
tail wakes up periodically even for unchanging files therefore
causing the check for "S (sleeping)" state to fail intermittently.
* tests/tail-2/wait: Likewise.
* NEWS: Document the new feature.
* m4/jm-macros.m4: Check if inotify is present.
* src/tail.c (tail_forever_inotify): New function.
(main): Use the inotify-based function, if possible.
* tests/Makefile.am: Add new tests for tail.
* tests/test-lib.sh (require_proc_pid_status_, get_process_status_):
New functions.
* tests/tail-2/pid: New file.
* tests/tail-2/wait: New file.
* tests/tail-2/tail-n0f: Refactor code into the test-lib.sh
require_proc_pid_status_ function.
