kernel/git - git - PowerEL Git System

Author	SHA1	Message	Date
Junio C Hamano	125fd98434	Make ce_uptodate() trustworthy again The rule has always been that a cache entry that is ce_uptodate(ce) means that we already have checked the work tree entity and we know there is no change in the work tree compared to the index, and nobody should have to double check. Note that false ce_uptodate(ce) does not mean it is known to be dirty---it only means we don't know if it is clean. There are a few codepaths (refresh-index and preload-index are among them) that mark a cache entry as up-to-date based solely on the return value from ie_match_stat(); this function uses lstat() to see if the work tree entity has been touched, and for a submodule entry, if its HEAD points at the same commit as the commit recorded in the index of the superproject (a submodule that is not even cloned is considered clean). A submodule is no longer considered unmodified merely because its HEAD matches the index of the superproject these days, in order to prevent people from forgetting to commit in the submodule and updating the superproject index with the new submodule commit, before commiting the state in the superproject. However, the patch to do so didn't update the codepath that marks cache entries up-to-date based on the updated definition and instead worked it around by saying "we don't trust the return value of ce_uptodate() for submodules." This makes ce_uptodate() trustworthy again by not marking submodule entries up-to-date. The next step _could_ be to introduce a few "in-core" flag bits to cache_entry structure to record "this entry is _known_ to be dirty", call is_submodule_modified() from ie_match_stat(), and use these new bits to avoid running this rather expensive check more than once, but that can be a separate patch. Signed-off-by: Junio C Hamano <gitster@pobox.com>	15 years ago
Pierre Habouzit	98cb6f30f7	janitor: add DIV_ROUND_UP and use it. Signed-off-by: Pierre Habouzit <madcoder@debian.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	16 years ago
Linus Torvalds	f62ce3de9d	Make index preloading check the whole path to the file This uses the new thread-safe 'threaded_has_symlink_leading_path()' function to efficiently verify that the whole path leading up to the filename is a proper path, and does not contain symlinks. This makes 'ce_uptodate()' a much stronger guarantee: it no longer just guarantees that the 'lstat()' of the path would match, it also means that we know that people haven't played games with moving directories around and covered it up with symlinks. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	16 years ago
Junio C Hamano	46059cc632	Makefile: introduce NO_PTHREADS This introduces make variable NO_PTHREADS for platforms that lack the support for pthreads library or people who do not want to use it for whatever reason. When defined, it makes the multi-threaded index preloading into a no-op, and also disables threaded delta searching by pack-objects. Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Mike Ralphson <mike@abacus.co.uk> Tested-by: Johannes Sixt <j6t@kdbg.org> (AIX 4.3.x) Signed-off-by: Junio C Hamano <gitster@pobox.com>	16 years ago
Linus Torvalds	7c4ea599b0	Fix index preloading for racy dirty case In the threaded index preloading case, we must be sure to always use the CE_MATCH_RACY_IS_DIRTY flag when calling ie_match_stat(), in order to make sure that we only ever look at the stat() data, and don't try to do anything fancy. Because most of git internals are not thread-safe, and must not be called in parallel. Otherwise, what happens is that if the timestamps indicate that an entry _might_ be dirty, we might start actually comparing filesystem data with the object database. And we mustn't do that, because that would involve looking up and creating the object structure, and that whole code sequence with read_sha1_file() where we look up and add objects to the hashes is definitely not thread-safe. Nor do we want to add locking, because the whole point of the preload was to be simple and not affect anything else. With CE_MATCH_RACY_IS_DIRTY, we get what we wanted, and we'll just leave the hard cases well alone, to be done later in the much simpler serial case. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	16 years ago
Linus Torvalds	671c9b7e31	Add cache preload facility This can do the lstat() storm in parallel, giving potentially much improved performance for cold-cache cases or things like NFS that have weak metadata caching. Just use "read_cache_preload()" instead of "read_cache()" to force an optimistic preload of the index stat data. The function takes a pathspec as its argument, allowing us to preload only the relevant portion of the index. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>	16 years ago