nfs: disable leases over NFS (370f6599) · Commits · 戴 / test

As Peter Staubach says elsewhere (http://marc.info/?l=linux-kernel&m=118113649526444&w=2 ): > The problem is that some file system such as NFSv2 and NFSv3 do > not have sufficient support to be able to support leases correctly. > In particular for these two file systems, there is no over the wire > protocol support. > > Currently, these two file systems fail the fcntl(F_SETLEASE) call > accidentally, due to a reference counting difference. These file > systems should fail more consciously, with a proper error to > indicate that the call is invalid for them. Define an nfs setlease method that just returns -EINVAL. If someone can demonstrate a real need, perhaps we could reenable them in the presence of the "nolock" mount option. Signed-off-by:

"J. Bruce Fields" <bfields@citi.umich.edu> Cc: Peter Staubach <staubach@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/file.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -53,6 +53,7 @@ static int nfs_fsync(struct file , struct dentry dentry, int datasync);
		static int nfs_check_flags(int flags);
		static int nfs_lock(struct file filp, int cmd, struct file_lock fl);
		static int nfs_flock(struct file filp, int cmd, struct file_lock fl);
		static int nfs_setlease(struct file file, long arg, struct file_lock *fl);

		const struct file_operations nfs_file_operations = {
		.llseek = nfs_file_llseek,
		@@ -69,6 +70,7 @@ const struct file_operations nfs_file_operations = {
		.flock = nfs_flock,
		.splice_read = nfs_file_splice_read,
		.check_flags = nfs_check_flags,
		.setlease = nfs_setlease,
		};

		const struct inode_operations nfs_file_inode_operations = {
		@@ -558,3 +560,13 @@ static int nfs_flock(struct file filp, int cmd, struct file_lock fl)
		return do_unlk(filp, cmd, fl);
		return do_setlk(filp, cmd, fl);
		}

		static int nfs_setlease(struct file file, long arg, struct file_lock *fl)
		{
		/*
		* There is no protocol support for leases, so we have no way
		* to implement them correctly in the face of opens by other
		* clients.
		*/
		return -EINVAL;
		}

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