From 0407c1bef9f5bc39da0fcf2e21bc5bd8b48b5349 Mon Sep 17 00:00:00 2001 From: Sami Kerola Date: Wed, 16 Jul 2014 21:54:57 +0100 Subject: fallocate: avoid unnecessary computation Where POSIX_FADV_SEQUENTIAL and HAVE_POSIX_FADVISE are not available it is waste of resources to have variables that are meaningful only for posix_fadvise(). Also initialize the variables immediately to correct values, and since cachesz is never changed mark it read only. Signed-off-by: Sami Kerola --- sys-utils/fallocate.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) (limited to 'sys-utils/fallocate.c') diff --git a/sys-utils/fallocate.c b/sys-utils/fallocate.c index 93fd3b48e..c619f64cc 100644 --- a/sys-utils/fallocate.c +++ b/sys-utils/fallocate.c @@ -174,17 +174,12 @@ static void dig_holes(int fd, off_t off, off_t len) { off_t end = len ? off + len : 0; off_t hole_start = 0, hole_sz = 0; - off_t cache_start = 0; uintmax_t ct = 0; - size_t bufsz, cachesz; + size_t bufsz; char *buf; struct stat st; - - if (fstat(fd, &st) != 0) - err(EXIT_FAILURE, _("stat failed %s"), filename); - - bufsz = st.st_blksize; - +#if defined(POSIX_FADV_SEQUENTIAL) && defined(HAVE_POSIX_FADVISE) + off_t cache_start = off; /* * We don't want to call POSIX_FADV_DONTNEED to discard cached * data in PAGE_SIZE steps. IMHO it's overkill (too many syscalls). @@ -193,15 +188,19 @@ static void dig_holes(int fd, off_t off, off_t len) * a good compromise. * -- kzak Feb-2014 */ - cachesz = getpagesize() * 256; + const size_t cachesz = getpagesize() * 256; +#endif + + if (fstat(fd, &st) != 0) + err(EXIT_FAILURE, _("stat failed %s"), filename); + + bufsz = st.st_blksize; if (lseek(fd, off, SEEK_SET) < 0) err(EXIT_FAILURE, _("seek on %s failed"), filename); /* buffer + extra space for is_nul() sentinel */ buf = xmalloc(bufsz + sizeof(uintptr_t)); - cache_start = off; - #if defined(POSIX_FADV_SEQUENTIAL) && defined(HAVE_POSIX_FADVISE) posix_fadvise(fd, off, 0, POSIX_FADV_SEQUENTIAL); #endif -- cgit v1.2.3-55-g7522