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Subject: Re: [PATCH nfs-utils 1/2] Remove 'force' arg from cache_flush()

On 5/20/21 9:40 PM, NeilBrown wrote:
>
> Since v4.17 the timestamp written to 'flush' is ignored,
> so there isn't much point choosing too precisely.
>
> For kernels since v4.3-rc3-13-g778620364ef5 it is safe
> to write 1 second beyond the current time.
>
> For earlier kernels, nothing is really safe (even the current
> behaviour), but writing one second beyond the current time isn't too bad
> in the unlikely case the people use a new nfs-utils on a 5 year old
> kernel.
>
> This remove a dependency for libnfs.a on 'etab' being declare,
> so svcgssd no longer needs to declare it.
>
> Signed-off-by: NeilBrown <[email protected]>
Committed... (tag: nfs-utils-2-5-4-rc4)

steved.
> ---
> support/export/auth.c | 2 +-
> support/include/nfslib.h | 2 +-
> support/nfs/cacheio.c | 17 ++++++++---------
> utils/exportfs/exportfs.c | 4 ++--
> utils/gssd/svcgssd.c | 1 -
> 5 files changed, 12 insertions(+), 14 deletions(-)
>
> diff --git a/support/export/auth.c b/support/export/auth.c
> index cea376300d01..17bdfc83748e 100644
> --- a/support/export/auth.c
> +++ b/support/export/auth.c
> @@ -80,7 +80,7 @@ check_useipaddr(void)
> use_ipaddr = 0;
>
> if (use_ipaddr != old_use_ipaddr)
> - cache_flush(1);
> + cache_flush();
> }
>
> unsigned int
> diff --git a/support/include/nfslib.h b/support/include/nfslib.h
> index 84d8270b330f..58eeb3382fcc 100644
> --- a/support/include/nfslib.h
> +++ b/support/include/nfslib.h
> @@ -132,7 +132,7 @@ int wildmat(char *text, char *pattern);
>
> int qword_get(char **bpp, char *dest, int bufsize);
> int qword_get_int(char **bpp, int *anint);
> -void cache_flush(int force);
> +void cache_flush(void);
> void qword_add(char **bpp, int *lp, char *str);
> void qword_addhex(char **bpp, int *lp, char *buf, int blen);
> void qword_addint(char **bpp, int *lp, int n);
> diff --git a/support/nfs/cacheio.c b/support/nfs/cacheio.c
> index 70ead94d64f0..73f4be4af9f9 100644
> --- a/support/nfs/cacheio.c
> +++ b/support/nfs/cacheio.c
> @@ -32,8 +32,6 @@
> #include <time.h>
> #include <errno.h>
>
> -extern struct state_paths etab;
> -
> void qword_add(char **bpp, int *lp, char *str)
> {
> char *bp = *bpp;
> @@ -213,7 +211,7 @@ int qword_get_uint(char **bpp, unsigned int *anint)
> */
>
> void
> -cache_flush(int force)
> +cache_flush(void)
> {
> struct stat stb;
> int c;
> @@ -234,12 +232,13 @@ cache_flush(int force)
> NULL
> };
> now = time(0);
> - if (force ||
> - stat(etab.statefn, &stb) != 0 ||
> - stb.st_mtime > now)
> - stb.st_mtime = time(0);
> -
> - sprintf(stime, "%" PRId64 "\n", (int64_t)stb.st_mtime);
> +
> + /* Since v4.16-rc2-3-g3b68e6ee3cbd the timestamp written is ignored.
> + * It is safest always to flush caches if there is any doubt.
> + * For earlier kernels, writing the next second from now is
> + * the best we can do.
> + */
> + sprintf(stime, "%" PRId64 "\n", (int64_t)now+1);
> for (c=0; cachelist[c]; c++) {
> int fd;
> sprintf(path, "/proc/net/rpc/%s/flush", cachelist[c]);
> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
> index bc76aaaf8714..d586296796a9 100644
> --- a/utils/exportfs/exportfs.c
> +++ b/utils/exportfs/exportfs.c
> @@ -188,7 +188,7 @@ main(int argc, char **argv)
>
> if (optind == argc && ! f_all) {
> if (force_flush) {
> - cache_flush(1);
> + cache_flush();
> free_state_path_names(&etab);
> return 0;
> } else {
> @@ -235,7 +235,7 @@ main(int argc, char **argv)
> unexportfs(argv[i], f_verbose);
> }
> xtab_export_write();
> - cache_flush(force_flush);
> + cache_flush();
> free_state_path_names(&etab);
> export_freeall();
>
> diff --git a/utils/gssd/svcgssd.c b/utils/gssd/svcgssd.c
> index 3ab2100b66bb..881207b3e8a2 100644
> --- a/utils/gssd/svcgssd.c
> +++ b/utils/gssd/svcgssd.c
> @@ -67,7 +67,6 @@
> #include "misc.h"
> #include "svcgssd_krb5.h"
>
> -struct state_paths etab; /* from cacheio.c */
> static bool signal_received = false;
> static struct event_base *evbase = NULL;
> static int nullrpc_fd = -1;
>