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| author | Dominique Martinet <asmadeus@codewreck.org> | 2022-06-13 08:32:06 +0900 |
|---|---|---|
| committer | Dominique Martinet <dominique.martinet@atmark-techno.com> | 2022-07-02 18:52:21 +0900 |
| commit | 286c171b86ebc693e18b485dde3a3fc470af37bd (patch) | |
| tree | a88cd5244bb6b8221928a2781e25fa7cd59ec2bb /include/net/9p | |
| parent | b48dbb998d70b7f48c2ec0a15c3cf47136808e4e (diff) | |
| download | linux-286c171b86ebc693e18b485dde3a3fc470af37bd.tar.bz2 | |
9p fid refcount: add a 9p_fid_ref tracepoint
This adds a tracepoint event for 9p fid lifecycle tracing: when a fid
is created, its reference count increased/decreased, and freed.
The new 9p_fid_ref tracepoint should help anyone wishing to debug any
fid problem such as missing clunk (destroy) or use-after-free.
Link: https://lkml.kernel.org/r/20220612085330.1451496-6-asmadeus@codewreck.org
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Diffstat (limited to 'include/net/9p')
| -rw-r--r-- | include/net/9p/client.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/net/9p/client.h b/include/net/9p/client.h index eabb53992350..8f629f1df865 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -11,6 +11,7 @@ #include <linux/utsname.h> #include <linux/idr.h> +#include <linux/tracepoint-defs.h> /* Number of requests per row */ #define P9_ROW_MAXTAG 255 @@ -237,6 +238,12 @@ static inline int p9_req_try_get(struct p9_req_t *r) int p9_req_put(struct p9_req_t *r); +/* We cannot have the real tracepoints in header files, + * use a wrapper function */ +DECLARE_TRACEPOINT(9p_fid_ref); +void do_trace_9p_fid_get(struct p9_fid *fid); +void do_trace_9p_fid_put(struct p9_fid *fid); + /* 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() @@ -249,6 +256,9 @@ int p9_req_put(struct p9_req_t *r); */ static inline struct p9_fid *p9_fid_get(struct p9_fid *fid) { + if (tracepoint_enabled(9p_fid_ref)) + do_trace_9p_fid_get(fid); + refcount_inc(&fid->count); return fid; @@ -259,6 +269,9 @@ static inline int p9_fid_put(struct p9_fid *fid) if (!fid || IS_ERR(fid)) return 0; + if (tracepoint_enabled(9p_fid_ref)) + do_trace_9p_fid_put(fid); + if (!refcount_dec_and_test(&fid->count)) return 0; |