Hi,
On Fri, Jul 21, 2023 at 1:46 PM Jeff Layton <jlayton@xxxxxxxxxx> wrote:
>
> On Thu, 2023-07-20 at 08:58 -0400, 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.
> >
> > Signed-off-by: Alexander Aring <aahringo@xxxxxxxxxx>
> > ---
> > fs/lockd/svclock.c | 5 ++---
> > fs/nfsd/nfs4state.c | 11 ++++++++---
> > include/linux/exportfs.h | 1 +
> > 3 files changed, 11 insertions(+), 6 deletions(-)
> >
> > diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
> > index 62ef27a69a9e..54a67bd33843 100644
> > --- a/fs/lockd/svclock.c
> > +++ b/fs/lockd/svclock.c
> > @@ -483,9 +483,7 @@ 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;
> > @@ -499,7 +497,8 @@ 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 (!(inode->i_sb->s_export_op->flags & EXPORT_OP_SAFE_ASYNC_LOCK) &&
> > + nlmsvc_file_file(file)->f_op->lock) {
> > async_block = wait;
> > wait = 0;
> > }
> > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> > index 6e61fa3acaf1..efcea229d640 100644
> > --- a/fs/nfsd/nfs4state.c
> > +++ b/fs/nfsd/nfs4state.c
> > @@ -7432,6 +7432,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> > struct nfsd4_blocked_lock *nbl = NULL;
> > struct file_lock *file_lock = NULL;
> > struct file_lock *conflock = NULL;
> > + struct super_block *sb;
> > __be32 status = 0;
> > int lkflg;
> > int err;
> > @@ -7453,6 +7454,7 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> > dprintk("NFSD: nfsd4_lock: permission denied!\n");
> > return status;
> > }
> > + sb = cstate->current_fh.fh_dentry->d_sb;
> >
> > if (lock->lk_is_new) {
> > if (nfsd4_has_session(cstate))
> > @@ -7504,7 +7506,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
> > fp = lock_stp->st_stid.sc_file;
> > switch (lock->lk_type) {
> > case NFS4_READW_LT:
> > - if (nfsd4_has_session(cstate))
> > + if (sb->s_export_op->flags & EXPORT_OP_SAFE_ASYNC_LOCK &&
>
> This will break existing filesystems that don't set the new flag. Maybe
> you also need to test for the filesystem's ->lock operation here too?
>
yes.
> This might be more nicely expressed in a helper function.
ok.
- Alex
