From 7b0e4faaf3169c69828d3f7769ed8ce9142e100b Mon Sep 17 00:00:00 2001 From: Ben Myers Date: Fri, 12 Feb 2010 14:02:21 -0500 Subject: [PATCH] nfs-utils: don't fdatasync the rmtab If we're using the new caching interface the rmtab will be ignored by exportfs so there is no need to fdatasync. This improves mountd performance. Signed-off-by: Steve Dickson --- support/nfs/cacheio.c | 5 ++--- support/nfs/rmtab.c | 23 ++++++++++++++++++----- 2 files changed, 20 insertions(+), 8 deletions(-) diff --git a/support/nfs/cacheio.c b/support/nfs/cacheio.c index 6a6ed5a..bdf5d84 100644 --- a/support/nfs/cacheio.c +++ b/support/nfs/cacheio.c @@ -285,9 +285,8 @@ int readline(int fd, char **buf, int *lenp) int check_new_cache(void) { - struct stat stb; - return (stat("/proc/fs/nfs/filehandle", &stb) == 0) || - (stat("/proc/fs/nfsd/filehandle", &stb) == 0); + return (access("/proc/fs/nfs/filehandle", F_OK) == 0) || + (access("/proc/fs/nfsd/filehandle", F_OK) == 0); } diff --git a/support/nfs/rmtab.c b/support/nfs/rmtab.c index 4cbd285..a28abf3 100644 --- a/support/nfs/rmtab.c +++ b/support/nfs/rmtab.c @@ -117,11 +117,24 @@ void fendrmtabent(FILE *fp) { if (fp) { - /* If it was written to, we really want - * to flush to disk before returning - */ - fflush(fp); - fdatasync(fileno(fp)); + static int have_new_cache = -1; + if (have_new_cache == -1) /* check only once */ + have_new_cache = check_new_cache(); + + if (!have_new_cache) { + /* + * If we are using the old caching interface: exportfs + * uses the rmtab to determine what should be exported, + * so it is important that it be up-to-date. + * + * If we are using the new caching interface: the rmtab + * is ignored by exportfs and the fdatasync only serves + * to slow us down. + */ + fflush(fp); + fdatasync(fileno(fp)); + } + fclose(fp); } } -- 2.39.2