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authorJ. Bruce Fields <bfields@citi.umich.edu>2007-06-08 15:23:34 -0400
committerJ. Bruce Fields <bfields@citi.umich.edu>2007-07-18 19:17:19 -0400
commit370f6599e8bc03fd9fc6d1a1be00ae0c6373ca59 (patch)
treea68ac809ec45dd09d9a24250f8ebcf3825ccea23
parent60446067ba7a8e890a91db3b4a7436fe0ebd2dee (diff)
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" <bfields@citi.umich.edu> Cc: Peter Staubach <staubach@redhat.com> Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
-rw-r--r--fs/nfs/file.c12
1 files changed, 12 insertions, 0 deletions
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;
+}