From e93a5e9306a576011f03011b492d4fbaa274477b Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 7 May 2021 10:06:13 -0400 Subject: NFSv4: Add support for application leases underpinned by a delegation If the NFSv4 client already holds a delegation for a file, then we can support application leases (i.e. fcntl(fd, F_SETLEASE,...)) because the underlying delegation guarantees that the file is not being modified on the server by another client in a way that might conflict with the lease guarantees. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'fs/nfs/nfs4proc.c') diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index e653654c10bc..35df44ef2c35 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -7438,6 +7438,43 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request) return nfs4_retry_setlk(state, cmd, request); } +static int nfs4_delete_lease(struct file *file, void **priv) +{ + return generic_setlease(file, F_UNLCK, NULL, priv); +} + +static int nfs4_add_lease(struct file *file, long arg, struct file_lock **lease, + void **priv) +{ + struct inode *inode = file_inode(file); + fmode_t type = arg == F_RDLCK ? FMODE_READ : FMODE_WRITE; + int ret; + + /* No delegation, no lease */ + if (!nfs4_have_delegation(inode, type)) + return -ENOLCK; + ret = generic_setlease(file, arg, lease, priv); + if (ret || nfs4_have_delegation(inode, type)) + return ret; + /* We raced with a delegation return */ + nfs4_delete_lease(file, priv); + return -ENOLCK; +} + +int nfs4_proc_setlease(struct file *file, long arg, struct file_lock **lease, + void **priv) +{ + switch (arg) { + case F_RDLCK: + case F_WRLCK: + return nfs4_add_lease(file, arg, lease, priv); + case F_UNLCK: + return nfs4_delete_lease(file, priv); + default: + return -EINVAL; + } +} + int nfs4_lock_delegation_recall(struct file_lock *fl, struct nfs4_state *state, const nfs4_stateid *stateid) { struct nfs_server *server = NFS_SERVER(state->inode); -- cgit