NFSv4: add flock_owner to open context
An open file description (struct file) in a given process can be
associated with two different lock owners.
It can have a Posix lock owner which will be different in each process
that has a fd on the file.
It can have a Flock owner which will be the same in all processes.
When searching for a lock stateid to use, we need to consider both of these
owners
So add a new "flock_owner" to the "nfs_open_context" (of which there
is one for each open file description).
This flock_owner does not need to be reference-counted as there is a
1-1 relation between 'struct file' and nfs open contexts,
and it will never be part of a list of contexts. So there is no need
for a 'flock_context' - just the owner is enough.
The io_count included in the (Posix) lock_context provides no
guarantee that all read-aheads that could use the state have
completed, so not supporting it for flock locks in not a serious
problem. Synchronization between flock and read-ahead can be added
later if needed.
When creating an open_context for a non-openning create call, we don't have
a 'struct file' to pass in, so the lock context gets initialized with
a NULL owner, but this will never be used.
The flock_owner is not used at all in this patch, that will come later.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index fd99132..3a7601f 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -796,7 +796,9 @@
}
EXPORT_SYMBOL_GPL(nfs_close_context);
-struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry, fmode_t f_mode)
+struct nfs_open_context *alloc_nfs_open_context(struct dentry *dentry,
+ fmode_t f_mode,
+ struct file *filp)
{
struct nfs_open_context *ctx;
struct rpc_cred *cred = rpc_lookup_cred();
@@ -815,6 +817,7 @@
ctx->mode = f_mode;
ctx->flags = 0;
ctx->error = 0;
+ ctx->flock_owner = (fl_owner_t)filp;
nfs_init_lock_context(&ctx->lock_context);
ctx->lock_context.open_context = ctx;
INIT_LIST_HEAD(&ctx->list);
@@ -939,7 +942,7 @@
{
struct nfs_open_context *ctx;
- ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode);
+ ctx = alloc_nfs_open_context(file_dentry(filp), filp->f_mode, filp);
if (IS_ERR(ctx))
return PTR_ERR(ctx);
nfs_file_set_open_context(filp, ctx);