From 370f6599e8bc03fd9fc6d1a1be00ae0c6373ca59 Mon Sep 17 00:00:00 2001 From: "J. Bruce Fields" Date: Fri, 8 Jun 2007 15:23:34 -0400 Subject: [PATCH] nfs: disable leases over NFS 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" Cc: Peter Staubach Cc: Trond Myklebust --- fs/nfs/file.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/fs/nfs/file.c b/fs/nfs/file.c index 8689b736fdd9..13ac6fa2b62b 100644 --- a/fs/nfs/file.c +++ b/fs/nfs/file.c @@ -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; +}