On Wed, Aug 23, 2023 at 05:33:46PM -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. > > Acked-by: Jeff Layton <jlay...@kernel.org> > Signed-off-by: Alexander Aring <aahri...@redhat.com> > --- > fs/lockd/svclock.c | 5 ++--- > fs/nfsd/nfs4state.c | 13 ++++++++++--- > include/linux/exportfs.h | 8 ++++++++ > 3 files changed, 20 insertions(+), 6 deletions(-)
I'm starting to look at these. Just so you know, it's too late for inclusion in v6.6, but I think we can get these into shape for v6.7. More below. > 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)) { > async_block = wait; > wait = 0; > } > diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c > index 3aefbad4cc09..14ca06424ff1 100644 > --- a/fs/nfsd/nfs4state.c > +++ b/fs/nfsd/nfs4state.c > @@ -7430,6 +7430,7 @@ 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; > @@ -7451,6 +7452,7 @@ 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)) > @@ -7502,7 +7504,9 @@ 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 (nfsd4_has_session(cstate) || > + export_op_support_safe_async_lock(sb->s_export_op, > + > nf->nf_file->f_op)) > fl_flags |= FL_SLEEP; > fallthrough; > case NFS4_READ_LT: > @@ -7514,7 +7518,9 @@ nfsd4_lock(struct svc_rqst *rqstp, struct > nfsd4_compound_state *cstate, > fl_type = F_RDLCK; > break; > case NFS4_WRITEW_LT: > - if (nfsd4_has_session(cstate)) > + if (nfsd4_has_session(cstate) || > + export_op_support_safe_async_lock(sb->s_export_op, > + > nf->nf_file->f_op)) > fl_flags |= FL_SLEEP; > fallthrough; > case NFS4_WRITE_LT: > @@ -7542,7 +7548,8 @@ nfsd4_lock(struct svc_rqst *rqstp, struct > nfsd4_compound_state *cstate, > * for file locks), so don't attempt blocking lock notifications > * on those filesystems: > */ > - if (nf->nf_file->f_op->lock) > + if (!export_op_support_safe_async_lock(sb->s_export_op, > + nf->nf_file->f_op)) > fl_flags &= ~FL_SLEEP; > > nbl = find_or_allocate_block(lock_sop, &fp->fi_fhandle, nn); > diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h > index 11fbd0ee1370..10358a93cdc1 100644 > --- a/include/linux/exportfs.h > +++ b/include/linux/exportfs.h > @@ -3,6 +3,7 @@ > #define LINUX_EXPORTFS_H 1 > > #include <linux/types.h> > +#include <linux/fs.h> > > struct dentry; > struct iattr; > @@ -224,9 +225,16 @@ struct export_operations { > atomic attribute updates > */ > #define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close > */ > +#define EXPORT_OP_SAFE_ASYNC_LOCK (0x40) /* fs can do async lock request > */ We haven't been good about this recently, but the addition of new EXPORT_OP flags need to be accompanied by updates to Documentation/filesystems/nfs/exporting.rst. I will see about adding documentation for other recent flags, but please include an update to exporting.rst with this patch. I'm not sure we need _SAFE_ in the flag name. Would EXPORT_OP_ASYNC_LOCK be OK with you? > unsigned long flags; > }; > > +static inline bool export_op_support_safe_async_lock(const struct > export_operations *export_ops, > + const struct > file_operations *f_op) > +{ > + return (export_ops->flags & EXPORT_OP_SAFE_ASYNC_LOCK) || !f_op->lock; > +} > + I'd like some cosmetic changes to this API, since this seems to be the first utility function for checking EXPORT_OP flags. - The function name is unwieldy. How about exportfs_lock_op_is_async() ? - Break up the long lines. It's OK with me if the return value type is left on a different line than the function name and parameters. - This function is globally visible, so a kdoc comment is needed. - The f_op->lock check is common to all the call sites, but it is not at all related to the export AFAICT. Can it be removed from this inline function? > extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid, > int *max_len, struct inode *parent, > int flags); > -- > 2.31.1 > -- Chuck Lever