> On Mar 19, 2021, at 6:39 PM, NeilBrown <neilb@xxxxxxx> wrote:
>
>
> It is possible (and common with the Linux NFS client) for the nfs server
> to receive multiple SET_CLIENT_ID or EXCHANGE_ID requests when starting
> a connection. This results in some clients appearing in
> /proc/fs/nfsd/clients
> which never get confirmed. mountd currently logs these, but they aren't
> really helpful.
>
> If the kernel supports the reporting of the confirmation status of
> clients, we can suppress the message until a client is confirmed.
>
> With this patch we:
> - record if the client is confirmed, assuming it is if the status is
> not reported
> - don't log unconfirmed clients
> - request MODIFY notification from unconfirmed clients.
> - recheck an info file when it is modified.
>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
Hello Neil!
I've committed v2 of this patch to the for-next topic branch at
git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git
> ---
> support/export/v4clients.c | 86 +++++++++++++++++++++++++++++---------
> 1 file changed, 67 insertions(+), 19 deletions(-)
>
> diff --git a/support/export/v4clients.c b/support/export/v4clients.c
> index 056ddc9b065d..f2c9bb482ba7 100644
> --- a/support/export/v4clients.c
> +++ b/support/export/v4clients.c
> @@ -48,12 +48,15 @@ void v4clients_set_fds(fd_set *fdset)
> }
>
> static void *tree_root;
> +static int have_unconfirmed;
>
> struct ent {
> unsigned long num;
> char *clientid;
> char *addr;
> int vers;
> + int unconfirmed;
> + int wid;
> };
>
> static int ent_cmp(const void *av, const void *bv)
> @@ -89,15 +92,14 @@ static char *dup_line(char *line)
> return ret;
> }
>
> -static void add_id(int id)
> +static void read_info(struct ent *key)
> {
> char buf[2048];
> - struct ent **ent;
> - struct ent *key;
> char *path;
> + int was_unconfirmed = key->unconfirmed;
> FILE *f;
>
> - if (asprintf(&path, "/proc/fs/nfsd/clients/%d/info", id) < 0)
> + if (asprintf(&path, "/proc/fs/nfsd/clients/%lu/info", key->num) < 0)
> return;
>
> f = fopen(path, "r");
> @@ -105,35 +107,64 @@ static void add_id(int id)
> free(path);
> return;
> }
> - key = calloc(1, sizeof(*key));
> - if (!key) {
> - fclose(f);
> - free(path);
> - return;
> - }
> - key->num = id;
> + if (key->wid < 0)
> + key->wid = inotify_add_watch(clients_fd, path, IN_MODIFY);
> +
> while (fgets(buf, sizeof(buf), f)) {
> - if (strncmp(buf, "clientid: ", 10) == 0)
> + if (strncmp(buf, "clientid: ", 10) == 0) {
> + free(key->clientid);
> key->clientid = dup_line(buf+10);
> - if (strncmp(buf, "address: ", 9) == 0)
> + }
> + if (strncmp(buf, "address: ", 9) == 0) {
> + free(key->addr);
> key->addr = dup_line(buf+9);
> + }
> if (strncmp(buf, "minor version: ", 15) == 0)
> key->vers = atoi(buf+15);
> + if (strncmp(buf, "status: ", 8) == 0 &&
> + strstr(buf, " unconfirmed") != NULL) {
> + key->unconfirmed = 1;
> + have_unconfirmed = 1;
> + }
> + if (strncmp(buf, "status: ", 8) == 0 &&
> + strstr(buf, " confirmed") != NULL)
> + key->unconfirmed = 0;
> }
> fclose(f);
> free(path);
>
> - xlog(L_NOTICE, "v4.%d client attached: %s from %s",
> - key->vers, key->clientid, key->addr);
> + if (was_unconfirmed && !key->unconfirmed)
> + xlog(L_NOTICE, "v4.%d client attached: %s from %s",
> + key->vers, key->clientid ?: "-none-",
> + key->addr ?: "-none-");
> + if (!key->unconfirmed && ent->wid >= 0) {
> + inotify_rm_watch(clients_fd, ent->wid);
> + ent->wid = -1;
> + }
> +}
> +
> +static void add_id(int id)
> +{
> + struct ent **ent;
> + struct ent *key;
> +
> + key = calloc(1, sizeof(*key));
> + if (!key) {
> + return;
> + }
> + key->num = id;
> + key->wid = -1;
>
> ent = tsearch(key, &tree_root, ent_cmp);
>
> if (!ent || *ent != key)
> /* Already existed, or insertion failed */
> free_ent(key);
> + else
> + read_info(key);
> }
>
> -static void del_id(int id)
> +static void del_id(unsigned long id)
> {
> struct ent key = {.num = id};
> struct ent **e, *ent;
> @@ -143,11 +174,27 @@ static void del_id(int id)
> return;
> ent = *e;
> tdelete(ent, &tree_root, ent_cmp);
> - xlog(L_NOTICE, "v4.%d client detached: %s from %s",
> - ent->vers, ent->clientid, ent->addr);
> + if (!ent->unconfirmed)
> + xlog(L_NOTICE, "v4.%d client detached: %s from %s",
> + ent->vers, ent->clientid, ent->addr);
> + if (ent->wid >= 0)
> + inotify_rm_watch(clients_fd, ent->wid);
> free_ent(ent);
> }
>
> +static void check_id(unsigned long id)
> +{
> + struct ent key = {.num = id};
> + struct ent **e, *ent;
> +
> + e = tfind(&key, &tree_root, ent_cmp);
> + if (!e || !*e)
> + return;
> + ent = *e;
> + if (ent->unconfirmed)
> + read_info(ent);
> +}
> +
> int v4clients_process(fd_set *fdset)
> {
> char buf[4096] __attribute__((aligned(__alignof__(struct inotify_event))));
> @@ -172,8 +219,9 @@ int v4clients_process(fd_set *fdset)
> add_id(id);
> if (ev->mask & IN_DELETE)
> del_id(id);
> + if (ev->mask & IN_MODIFY)
> + check_id(id);
> }
> }
> return 1;
> }
> -
> --
> 2.30.1
>
--
Chuck Lever
