This patch reverts mostly commit 40595cdc93ed ("nfs: block notification
on fs with its own ->lock") and introduces an EXPORT_OP_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_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>
---
Documentation/filesystems/nfs/exporting.rst | 7 +++++++
fs/lockd/svclock.c | 4 +---
fs/nfsd/nfs4state.c | 10 +++++++---
include/linux/exportfs.h | 14 ++++++++++++++
4 files changed, 29 insertions(+), 6 deletions(-)
diff --git a/Documentation/filesystems/nfs/exporting.rst b/Documentation/filesystems/nfs/exporting.rst
index 4b30daee399a..198d805d611c 100644
--- a/Documentation/filesystems/nfs/exporting.rst
+++ b/Documentation/filesystems/nfs/exporting.rst
@@ -241,3 +241,10 @@ following flags are defined:
all of an inode's dirty data on last close. Exports that behave this
way should set EXPORT_OP_FLUSH_ON_CLOSE so that NFSD knows to skip
waiting for writeback when closing such files.
+
+ EXPORT_OP_ASYNC_LOCK - Indicates a capable filesystem to do async lock
+ requests from lockd. Only set EXPORT_OP_ASYNC_LOCK if the filesystem has
+ it's own ->lock() functionality as core posix_lock_file() implementation
+ has no async lock request handling yet. For more information about how to
+ indicate an async lock request from a ->lock() file_operations struct, see
+ fs/locks.c and comment for the function vfs_lock_file().
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index 43aeba9de55c..d500e32ebb18 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -481,9 +481,7 @@ 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;
@@ -497,7 +495,7 @@ 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 (!exportfs_lock_op_is_async(inode->i_sb->s_export_op)) {
async_block = wait;
wait = 0;
}
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 8534693eb6a4..7cabe882724e 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -7487,6 +7487,7 @@ 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;
@@ -7508,6 +7509,7 @@ 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))
@@ -7559,7 +7561,8 @@ 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 (nfsd4_has_session(cstate) ||
+ exportfs_lock_op_is_async(sb->s_export_op))
fl_flags |= FL_SLEEP;
fallthrough;
case NFS4_READ_LT:
@@ -7571,7 +7574,8 @@ 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) ||
+ exportfs_lock_op_is_async(sb->s_export_op))
fl_flags |= FL_SLEEP;
fallthrough;
case NFS4_WRITE_LT:
@@ -7599,7 +7603,7 @@ 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 (!exportfs_lock_op_is_async(sb->s_export_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..6dd993240fcc 100644
--- a/include/linux/exportfs.h
+++ b/include/linux/exportfs.h
@@ -224,9 +224,23 @@ struct export_operations {
atomic attribute updates
*/
#define EXPORT_OP_FLUSH_ON_CLOSE (0x20) /* fs flushes file data on close */
+#define EXPORT_OP_ASYNC_LOCK (0x40) /* fs can do async lock request */
unsigned long flags;
};
+/**
+ * exportfs_lock_op_is_async() - export op supports async lock operation
+ * @export_ops: the nfs export operations to check
+ *
+ * Returns true if the nfs export_operations structure has
+ * EXPORT_OP_ASYNC_LOCK in their flags set
+ */
+static inline bool
+exportfs_lock_op_is_async(const struct export_operations *export_ops)
+{
+ return export_ops->flags & EXPORT_OP_ASYNC_LOCK;
+}
+
extern int exportfs_encode_inode_fh(struct inode *inode, struct fid *fid,
int *max_len, struct inode *parent,
int flags);
--
2.31.1
