| Message ID | 20230823213352.1971009-5-aahringo@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | lockd: dlm: async lock request changes | expand |
On Wed, 2023-08-23 at 17:33 -0400, Alexander Aring wrote: > This patch adds a note to enable EXPORT_OP_SAFE_ASYNC_LOCK for > asynchronous lock request handling. > > Signed-off-by: Alexander Aring <aahringo@redhat.com> > --- > fs/locks.c | 12 +++++++----- > 1 file changed, 7 insertions(+), 5 deletions(-) > > diff --git a/fs/locks.c b/fs/locks.c > index df8b26a42524..edee02d1ca93 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -2255,11 +2255,13 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock) > * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX > * locks, the ->lock() interface may return asynchronously, before the lock has > * been granted or denied by the underlying filesystem, if (and only if) > - * lm_grant is set. Callers expecting ->lock() to return asynchronously > - * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) > - * the request is for a blocking lock. When ->lock() does return asynchronously, > - * it must return FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock > - * request completes. > + * lm_grant is set. Additionally EXPORT_OP_SAFE_ASYNC_LOCK in export_operations > + * flags need to be set. > + * > + * Callers expecting ->lock() to return asynchronously will only use F_SETLK, > + * not F_SETLKW; they will set FL_SLEEP if (and only if) the request is for a > + * blocking lock. When ->lock() does return asynchronously, it must return > + * FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock request completes. > * If the request is for non-blocking lock the file system should return > * FILE_LOCK_DEFERRED then try to get the lock and call the callback routine > * with the result. If the request timed out the callback routine will return a Reviewed-by: Jeff Layton <jlayton@kernel.org>
diff --git a/fs/locks.c b/fs/locks.c index df8b26a42524..edee02d1ca93 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2255,11 +2255,13 @@ int fcntl_getlk(struct file *filp, unsigned int cmd, struct flock *flock) * To avoid blocking kernel daemons, such as lockd, that need to acquire POSIX * locks, the ->lock() interface may return asynchronously, before the lock has * been granted or denied by the underlying filesystem, if (and only if) - * lm_grant is set. Callers expecting ->lock() to return asynchronously - * will only use F_SETLK, not F_SETLKW; they will set FL_SLEEP if (and only if) - * the request is for a blocking lock. When ->lock() does return asynchronously, - * it must return FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock - * request completes. + * lm_grant is set. Additionally EXPORT_OP_SAFE_ASYNC_LOCK in export_operations + * flags need to be set. + * + * Callers expecting ->lock() to return asynchronously will only use F_SETLK, + * not F_SETLKW; they will set FL_SLEEP if (and only if) the request is for a + * blocking lock. When ->lock() does return asynchronously, it must return + * FILE_LOCK_DEFERRED, and call ->lm_grant() when the lock request completes. * If the request is for non-blocking lock the file system should return * FILE_LOCK_DEFERRED then try to get the lock and call the callback routine * with the result. If the request timed out the callback routine will return a
This patch adds a note to enable EXPORT_OP_SAFE_ASYNC_LOCK for asynchronous lock request handling. Signed-off-by: Alexander Aring <aahringo@redhat.com> --- fs/locks.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)