From 1b8ac5ead520146802debd52cb38e5c27b3483a2 Mon Sep 17 00:00:00 2001 From: Junio C Hamano Date: Fri, 28 Oct 2016 06:23:07 -0700 Subject: git_open(): untangle possible NOATIME and CLOEXEC interactions The way we structured the fallback/retry mechanism for opening with O_NOATIME and O_CLOEXEC meant that if we failed due to lack of support to open the file with O_NOATIME option (i.e. EINVAL), we would still try to drop O_CLOEXEC first and retry, and then drop O_NOATIME. A platform on which O_NOATIME is defined in the header without support from the kernel wouldn't have a chance to open with O_CLOEXEC option due to this code structure. Arguably, O_CLOEXEC is more important than O_NOATIME, as the latter is mostly about performance, while the former can affect correctness. Instead use O_CLOEXEC to open the file, and then use fcntl(2) to set O_NOATIME on the resulting file descriptor. open(2) itself does not cause atime to be updated according to Linus [*1*]. The helper to do the former can be usable in the codepath in ce_compare_data() that was recently added to open a file descriptor with O_CLOEXEC; use it while we are at it. *1* Signed-off-by: Junio C Hamano --- read-cache.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'read-cache.c') diff --git a/read-cache.c b/read-cache.c index db5d910642..c27d3e240b 100644 --- a/read-cache.c +++ b/read-cache.c @@ -156,14 +156,7 @@ void fill_stat_cache_info(struct cache_entry *ce, struct stat *st) static int ce_compare_data(const struct cache_entry *ce, struct stat *st) { int match = -1; - static int cloexec = O_CLOEXEC; - int fd = open(ce->name, O_RDONLY | cloexec); - - if ((cloexec & O_CLOEXEC) && fd < 0 && errno == EINVAL) { - /* Try again w/o O_CLOEXEC: the kernel might not support it */ - cloexec &= ~O_CLOEXEC; - fd = open(ce->name, O_RDONLY | cloexec); - } + int fd = git_open_cloexec(ce->name, O_RDONLY); if (fd >= 0) { unsigned char sha1[20]; -- cgit v1.3-5-g9baa