On 23 Aug 2023, at 17:33, Alexander Aring wrote:
> This patch reverts mostly commit 40595cdc93ed ("nfs: block notification
> on fs with its own ->lock") and introduces an EXPORT_OP_SAFE_ASYNC_LOCK
> export flag to signal that the "own ->lock" implementation supports
> async lock requests. The only main user is DLM that is used by GFS2 and
> OCFS2 filesystem. Those implement their own lock() implementation and
> return FILE_LOCK_DEFERRED as return value. Since commit 40595cdc93ed
> ("nfs: block notification on fs with its own ->lock") the DLM
> implementation were never updated. This patch should prepare for DLM
> to set the EXPORT_OP_SAFE_ASYNC_LOCK export flag and update the DLM
> plock implementation regarding to it.
>
> Acked-by: Jeff Layton <jlayton@xxxxxxxxxx>
> Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
> ---
> fs/lockd/svclock.c | 5 ++---
> fs/nfsd/nfs4state.c | 13 ++++++++++---
> include/linux/exportfs.h | 8 ++++++++
> 3 files changed, 20 insertions(+), 6 deletions(-)
>
> diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
> index c43ccdf28ed9..6e3b230e8317 100644
> --- a/fs/lockd/svclock.c
> +++ b/fs/lockd/svclock.c
> @@ -470,9 +470,7 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
> struct nlm_host *host, struct nlm_lock *lock, int wait,
> struct nlm_cookie *cookie, int reclaim)
> {
> -#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
> struct inode *inode = nlmsvc_file_inode(file);
> -#endif
> struct nlm_block *block = NULL;
> int error;
> int mode;
> @@ -486,7 +484,8 @@ nlmsvc_lock(struct svc_rqst *rqstp, struct nlm_file *file,
> (long long)lock->fl.fl_end,
> wait);
>
> - if (nlmsvc_file_file(file)->f_op->lock) {
> + if (!export_op_support_safe_async_lock(inode->i_sb->s_export_op,
> + nlmsvc_file_file(file)->f_op)) {
... but don't most filesystem use VFS' posix_lock_file(), which does the
right thing? I think this patch has broken async lock callbacks for NLM for
all the other filesystems that just use posix_lock_file().
Maybe I'm missing something, but why was that necessary?
Ben
