tree-wide: remove Emacs lines from all files This should be handled fine now by .dir-locals.el, so need to carry that stuff in every file.

remove unused includes This patch removes includes that are not used. The removals were found with include-what-you-use which checks if any of the symbols from a header is in use.

journald: process SIGBUS for the memory maps we set up Even though we use fallocate() it appears that file systems like btrfs will trigger SIGBUS on certain low-disk-space situation. We should handle that, hence catch the signal, add it to a list of invalidated pages, and replace the page with an empty memory area. After each write check if SIGBUS was triggered, and consider the write invalid if it was. This should make journald a lot more robust with file systems where fallocate() is not reliable, for example all CoW file systems (btrfs...), where changing written data can fail with disk full errors. https://bugzilla.redhat.com/show_bug.cgi?id=1045810

journal: replace contexts hashmap with a plain array try_context() is such a hot path that the hashmap lookup is expensive. The number of contexts is small - it is the number of object types. Using a hashmap is overkill. A plain array will do. Before: $ time ./journalctl --since=2014-06-01 --until=2014-07-01 > /dev/null real 0m9.445s user 0m9.228s sys 0m0.213s After: $ time ./journalctl --since=2014-06-01 --until=2014-07-01 > /dev/null real 0m5.438s user 0m5.266s sys 0m0.170s

journal: delete unused function mmap_cache_close_context This never had any callers. Contexts are freed when the MMapCache is freed.

journal: remove journal_file_object_keep/release functions The only user is sd_journal_enumerate_unique() and, as explained in the previous commit (fed67c38e3 "journal: map objects to context set by caller, not by actual object type"), the use of them there is now superfluous. Let's remove them. This reverts major parts of commits: ae97089d49 journal: fix access to munmapped memory in sd_journal_enumerate_unique 06cc69d44c sd-journal: fix sd_journal_enumerate_unique skipping values Tested with an "--enable-debug" build and "journalctl --list-boots". It gives the expected number of results. Additionally, if I then revert the previous commit ("journal: map objects to context set by caller, not to actual object type"), it crashes with SIGSEGV, as expected.

sd-journal: fix sd_journal_enumerate_unique skipping values sd_journal_enumerate_unique will lock its mmap window to prevent it from being released by calling mmap_cache_get with keep_always=true. This call may return windows that are wider, but compatible with the parameters provided to it. This can result in a mismatch where the window to be released cannot properly be selected, because we have more than one window matching the parameters of mmap_cache_release. Therefore, introduce a release_cookie to be used when releasing the window. https://bugs.freedesktop.org/show_bug.cgi?id=79380

journal: fix access to munmapped memory in sd_journal_enumerate_unique sd_j_e_u needs to keep a reference to an object while comparing it with possibly duplicate objects in other files. Because the size of mmap cache is limited, with enough files and object to compare to, at some point the object being compared would be munmapped, resulting in a segmentation fault. Fix this issue by turning keep_always into a reference count that can be increased and decreased. Other callers which set keep_always=true are unmodified: their references are never released but are ignored when the whole file is closed, which happens at some point. keep_always is increased in sd_j_e_u and later on released.

journald: keep statistics on how of we hit/miss the mmap cache

journal: bring mmap cache prototype in sync

journal: completely rework the mmap cache as I too dumb to actually understand it Instead of doing hand optimized fd bisect arrays just use plain old hashmaps. Now I can understand my own code again. Yay! As a side effect this should fix some bad memory accesses caused by accesses after mmap(), introduced in 189.

journal: be more careful when keeping around mmaps we still need

mmap: resize arrays dynamically

journal: add superficial structure verifier

journal: implement generic sharable mmap caching logic instead of having one simple per-file cache implement an more comprehensive one that works for multiple files and can actually maintain multiple maps per file and per object type.