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 <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(-)

diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index 1e74a578d7de..b8bd2b841ee1 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -449,9 +449,7 @@ 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;
@@ -465,7 +463,8 @@ 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 
*/
        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;
+}
+
 extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid,
                                    int *max_len, struct inode *parent,
                                    int flags);
-- 
2.31.1

Reply via email to