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author | NeilBrown <neilb@suse.de> | 2021-11-29 15:51:25 +1100 |
---|---|---|
committer | Chuck Lever <chuck.lever@oracle.com> | 2021-12-13 13:42:50 -0500 |
commit | 8c62d12740a1450d2e8456d5747f440e10db281a (patch) | |
tree | 4513a69e78c5a22609e43fde37354d15db2c0f58 /include/linux/sunrpc | |
parent | SUNRPC: change svc_get() to return the svc. (diff) | |
download | linux-8c62d12740a1450d2e8456d5747f440e10db281a.tar.gz linux-8c62d12740a1450d2e8456d5747f440e10db281a.tar.bz2 linux-8c62d12740a1450d2e8456d5747f440e10db281a.zip |
SUNRPC/NFSD: clean up get/put functions.
svc_destroy() is poorly named - it doesn't necessarily destroy the svc,
it might just reduce the ref count.
nfsd_destroy() is poorly named for the same reason.
This patch:
- removes the refcount functionality from svc_destroy(), moving it to
a new svc_put(). Almost all previous callers of svc_destroy() now
call svc_put().
- renames nfsd_destroy() to nfsd_put() and improves the code, using
the new svc_destroy() rather than svc_put()
- removes a few comments that explain the important for balanced
get/put calls. This should be obvious.
The only non-trivial part of this is that svc_destroy() would call
svc_sock_update() on a non-final decrement. It can no longer do that,
and svc_put() isn't really a good place of it. This call is now made
from svc_exit_thread() which seems like a good place. This makes the
call *before* sv_nrthreads is decremented rather than after. This
is not particularly important as the call just sets a flag which
causes sv_nrthreads set be checked later. A subsequent patch will
improve the ordering.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Diffstat (limited to 'include/linux/sunrpc')
-rw-r--r-- | include/linux/sunrpc/svc.h | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h index 5d9568953fcd..73d56d33a36d 100644 --- a/include/linux/sunrpc/svc.h +++ b/include/linux/sunrpc/svc.h @@ -114,8 +114,13 @@ struct svc_serv { #endif /* CONFIG_SUNRPC_BACKCHANNEL */ }; -/* - * We use sv_nrthreads as a reference count. svc_destroy() drops +/** + * svc_get() - increment reference count on a SUNRPC serv + * @serv: the svc_serv to have count incremented + * + * Returns: the svc_serv that was passed in. + * + * We use sv_nrthreads as a reference count. svc_put() drops * this refcount, so we need to bump it up around operations that * change the number of threads. Horrible, but there it is. * Should be called with the "service mutex" held. @@ -126,6 +131,22 @@ static inline struct svc_serv *svc_get(struct svc_serv *serv) return serv; } +void svc_destroy(struct svc_serv *serv); + +/** + * svc_put - decrement reference count on a SUNRPC serv + * @serv: the svc_serv to have count decremented + * + * When the reference count reaches zero, svc_destroy() + * is called to clean up and free the serv. + */ +static inline void svc_put(struct svc_serv *serv) +{ + serv->sv_nrthreads -= 1; + if (serv->sv_nrthreads == 0) + svc_destroy(serv); +} + /* * Maximum payload size supported by a kernel RPC server. * This is use to determine the max number of pages nfsd is @@ -515,7 +536,6 @@ struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int, int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int); int svc_set_num_threads_sync(struct svc_serv *, struct svc_pool *, int); int svc_pool_stats_open(struct svc_serv *serv, struct file *file); -void svc_destroy(struct svc_serv *); void svc_shutdown_net(struct svc_serv *, struct net *); int svc_process(struct svc_rqst *); int bc_svc_process(struct svc_serv *, struct rpc_rqst *, |