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authorBrian Behlendorf <[email protected]>2018-07-30 09:22:30 -0700
committerGitHub <[email protected]>2018-07-30 09:22:30 -0700
commit11d0525cbb15a3519df683ec0248b6ac55f9d090 (patch)
tree14fdc0c33c8972cdf79644c5306716ec4d95cb03 /include
parentfb7307b8922e9eb7da430733d6665e06d2cb0bf5 (diff)
Add rwsem_tryupgrade for 4.9.20-rt16 kernel
The RT rwsem implementation was changed to allow multiple readers as of the 4.9.20-rt16 patch set. This results in a build failure because the existing implementation was forced to directly access the rwsem structure which has changed. While this could be accommodated by adding additional compatibility code. This patch resolves the build issue by simply assuming the rwsem can never be upgraded. This functionality is a performance optimization and all callers must already handle this case. Converting the last remaining use of __SPIN_LOCK_UNLOCKED to spin_lock_init() was additionally required to get a clean build. Signed-off-by: Brian Behlendorf <[email protected]> Closes #7589
Diffstat (limited to 'include')
-rw-r--r--include/spl/sys/rwlock.h10
1 files changed, 5 insertions, 5 deletions
diff --git a/include/spl/sys/rwlock.h b/include/spl/sys/rwlock.h
index 088e28b44..0ac528e16 100644
--- a/include/spl/sys/rwlock.h
+++ b/include/spl/sys/rwlock.h
@@ -172,7 +172,7 @@ RW_LOCK_HELD(krwlock_t *rwp)
}
/*
- * The following functions must be a #define and not static inline.
+ * The following functions must be a #define and not static inline.
* This ensures that the native linux semaphore functions (down/up)
* will be correctly located in the users code which is important
* for the built in kernel lock analysis tools
@@ -188,10 +188,10 @@ RW_LOCK_HELD(krwlock_t *rwp)
spl_rw_set_type(rwp, type); \
})
-#define rw_destroy(rwp) \
-({ \
- VERIFY(!RW_LOCK_HELD(rwp)); \
-})
+/*
+ * The Linux rwsem implementation does not require a matching destroy.
+ */
+#define rw_destroy(rwp) ((void) 0)
#define rw_tryenter(rwp, rw) \
({ \