From b48dbb998d70b7f48c2ec0a15c3cf47136808e4e Mon Sep 17 00:00:00 2001 From: Dominique Martinet Date: Sun, 12 Jun 2022 13:42:32 +0900 Subject: 9p fid refcount: add p9_fid_get/put wrappers I was recently reminded that it is not clear that p9_client_clunk() was actually just decrementing refcount and clunking only when that reaches zero: make it clear through a set of helpers. This will also allow instrumenting refcounting better for debugging next patch Link: https://lkml.kernel.org/r/20220612085330.1451496-5-asmadeus@codewreck.org Reviewed-by: Tyler Hicks Reviewed-by: Christian Schoenebeck Signed-off-by: Dominique Martinet --- include/net/9p/client.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'include/net') diff --git a/include/net/9p/client.h b/include/net/9p/client.h index ec1d1706f43c..eabb53992350 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -237,6 +237,34 @@ static inline int p9_req_try_get(struct p9_req_t *r) int p9_req_put(struct p9_req_t *r); +/* fid reference counting helpers: + * - fids used for any length of time should always be referenced through + * p9_fid_get(), and released with p9_fid_put() + * - v9fs_fid_lookup() or similar will automatically call get for you + * and also require a put + * - the *_fid_add() helpers will stash the fid in the inode, + * at which point it is the responsibility of evict_inode() + * to call the put + * - the last put will automatically send a clunk to the server + */ +static inline struct p9_fid *p9_fid_get(struct p9_fid *fid) +{ + refcount_inc(&fid->count); + + return fid; +} + +static inline int p9_fid_put(struct p9_fid *fid) +{ + if (!fid || IS_ERR(fid)) + return 0; + + if (!refcount_dec_and_test(&fid->count)) + return 0; + + return p9_client_clunk(fid); +} + void p9_client_cb(struct p9_client *c, struct p9_req_t *req, int status); int p9_parse_header(struct p9_fcall *pdu, int32_t *size, int8_t *type, -- cgit v1.2.3