diff options
| author | Brian Behlendorf <[email protected]> | 2019-05-23 13:46:33 -0700 |
|---|---|---|
| committer | GitHub <[email protected]> | 2019-05-23 13:46:33 -0700 |
| commit | bff2361aeb32a83c26e2992733864ca99cced257 (patch) | |
| tree | ae45cdae978446595bbb160f20dae43ba9e79edb /module/spl/spl-rwlock.c | |
| parent | e34c3ee2fcbb320525a110c1811c557bc60479ff (diff) | |
Linux 5.2 compat: rw_tryupgrade()
Commit torvalds/linux@46ad0840b has removed the architecture specific
rwsem source and headers leaving only the generic version. As part
of this change the RWSEM_ACTIVE_READ_BIAS and RWSEM_ACTIVE_WRITE_BIAS
macros were moved to the private kernel/locking/rwsem.h header.
This results in a build failure because these macros were required
to implement the rw_tryupgrade() compatibility function.
In practice, this isn't a major problem because there are only a
few consumers of rw_tryupgrade() and because consumers of rw_tryupgrade
should be written to retry using rw_enter(RW_WRITER).
After auditing all of the callers only dmu_zfetch() was determined
not to perform a retry. It has been updated in this commit to
resolve this issue.
That said, the rw_tryupgrade() functionality should be considered
for possible removal in a future release due to the difficultly
in supporting the interface.
Reviewed-by: Tomohiro Kusumi <[email protected]>
Reviewed-by: Chunwei Chen <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes #8730
Diffstat (limited to 'module/spl/spl-rwlock.c')
| -rw-r--r-- | module/spl/spl-rwlock.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/module/spl/spl-rwlock.c b/module/spl/spl-rwlock.c index 4ffebc8ea..86727ed19 100644 --- a/module/spl/spl-rwlock.c +++ b/module/spl/spl-rwlock.c @@ -85,7 +85,8 @@ __rwsem_tryupgrade(struct rw_semaphore *rwsem) spl_rwsem_unlock_irqrestore(&rwsem->wait_lock, flags); return (ret); } -#elif defined(HAVE_RWSEM_ATOMIC_LONG_COUNT) +#elif defined(RWSEM_ACTIVE_MASK) +#if defined(HAVE_RWSEM_ATOMIC_LONG_COUNT) static int __rwsem_tryupgrade(struct rw_semaphore *rwsem) { @@ -104,6 +105,13 @@ __rwsem_tryupgrade(struct rw_semaphore *rwsem) return (val == SPL_RWSEM_SINGLE_READER_VALUE); } #endif +#else +static int +__rwsem_tryupgrade(struct rw_semaphore *rwsem) +{ + return (0); +} +#endif int rwsem_tryupgrade(struct rw_semaphore *rwsem) |