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authorJani Nikula <jani.nikula@intel.com>2020-12-16 07:45:57 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-16 09:46:18 +0300
commit023542f48b57d6b785fcadb86ac336ae80653e58 (patch)
treef2b8a53d46c70b307d66f3661c16805c07d81971 /include/linux/relay.h
parent371e03880d9d34534d3eafd2a7581042be598e39 (diff)
downloadlinux-023542f48b57d6b785fcadb86ac336ae80653e58.tar.xz
relay: allow the use of const callback structs
None of the relay users require the use of mutable structs for callbacks, however the relay code does. Instead of assigning the default callback for subbuf_start, add a wrapper to conditionally call the client callback if available, and fall back to default behaviour otherwise. This lets all relay users make their struct rchan_callbacks const data. [jani.nikula@intel.com: cleanups, per Christoph] Link: https://lkml.kernel.org/r/20201124115412.32402-1-jani.nikula@intel.com Link: https://lkml.kernel.org/r/cc3ff292e4eb4fdc56bee3d690c7b8e39209cd37.1606153547.git.jani.nikula@intel.com Signed-off-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Jens Axboe <axboe@kernel.dk> Cc: Kalle Valo <kvalo@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/relay.h')
-rw-r--r--include/linux/relay.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/relay.h b/include/linux/relay.h
index 99d024475ba5..72b876dd5cb8 100644
--- a/include/linux/relay.h
+++ b/include/linux/relay.h
@@ -62,7 +62,7 @@ struct rchan
size_t subbuf_size; /* sub-buffer size */
size_t n_subbufs; /* number of sub-buffers per buffer */
size_t alloc_size; /* total buffer size allocated */
- struct rchan_callbacks *cb; /* client callbacks */
+ const struct rchan_callbacks *cb; /* client callbacks */
struct kref kref; /* channel refcount */
void *private_data; /* for user-defined data */
size_t last_toobig; /* tried to log event > subbuf size */
@@ -157,7 +157,7 @@ struct rchan *relay_open(const char *base_filename,
struct dentry *parent,
size_t subbuf_size,
size_t n_subbufs,
- struct rchan_callbacks *cb,
+ const struct rchan_callbacks *cb,
void *private_data);
extern int relay_late_setup_files(struct rchan *chan,
const char *base_filename,