[PATCH 06/10] locks: plumb an "aux" pointer into the setlease routines

[Jeff Layton <jlayton-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org>]

In later patches, we're going to add a new lock_manager_operation to
finish setting up the lease while still holding the i_lock.  To do
this, we'll need to pass a little bit of info in the fcntl setlease
case (primarily an fasync structure). Plumb the extra pointer into
there in advance of that.

We declare this pointer as a void ** to make it clear that this is
auxillary info, and that the caller isn't required to set this unless
the lm_setup specifically requires it.

Signed-off-by: Jeff Layton <jlayton-7I+n7zu2hftEKMMhf/gKZA@public.gmane.org>
---
 fs/cifs/cifsfs.c    |  7 ++++---
 fs/gfs2/file.c      |  3 ++-
 fs/locks.c          | 33 +++++++++++++++++++++------------
 fs/nfs/file.c       |  2 +-
 fs/nfs/internal.h   |  2 +-
 fs/nfsd/nfs4state.c |  4 ++--
 include/linux/fs.h  | 10 +++++-----
 7 files changed, 36 insertions(+), 25 deletions(-)

diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 889b98455750..f463d86f097a 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -813,7 +813,8 @@ static loff_t cifs_llseek(struct file *file, loff_t offset, int whence)
 	return generic_file_llseek(file, offset, whence);
 }
 
-static int cifs_setlease(struct file *file, long arg, struct file_lock **lease)
+static int
+cifs_setlease(struct file *file, long arg, struct file_lock **lease, void **aux)
 {
 	/*
 	 * Note that this is called by vfs setlease with i_lock held to
@@ -829,7 +830,7 @@ static int cifs_setlease(struct file *file, long arg, struct file_lock **lease)
 	if (arg == F_UNLCK ||
 	    ((arg == F_RDLCK) && CIFS_CACHE_READ(CIFS_I(inode))) ||
 	    ((arg == F_WRLCK) && CIFS_CACHE_WRITE(CIFS_I(inode))))
-		return generic_setlease(file, arg, lease);
+		return generic_setlease(file, arg, lease, aux);
 	else if (tlink_tcon(cfile->tlink)->local_lease &&
 		 !CIFS_CACHE_READ(CIFS_I(inode)))
 		/*
@@ -840,7 +841,7 @@ static int cifs_setlease(struct file *file, long arg, struct file_lock **lease)
 		 * knows that the file won't be changed on the server by anyone
 		 * else.
 		 */
-		return generic_setlease(file, arg, lease);
+		return generic_setlease(file, arg, lease, aux);
 	else
 		return -EAGAIN;
 }
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 26b3f952e6b1..253feff90b4e 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -927,7 +927,8 @@ out_uninit:
  * Returns: errno
  */
 
-static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl)
+static int gfs2_setlease(struct file *file, long arg, struct file_lock **fl,
+			 void **aux)
 {
 	return -EINVAL;
 }
diff --git a/fs/locks.c b/fs/locks.c
index 597e71a1e90f..906e09da115a 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -1297,7 +1297,6 @@ int lease_modify(struct file_lock **before, int arg)
 	}
 	return 0;
 }
-
 EXPORT_SYMBOL(lease_modify);
 
 static bool past_time(unsigned long then)
@@ -1543,7 +1542,8 @@ check_conflicting_open(const struct dentry *dentry, const long arg)
 	return ret;
 }
 
-static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp)
+static int
+generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **aux)
 {
 	struct file_lock *fl, **before, **my_before = NULL, *lease;
 	struct dentry *dentry = filp->f_path.dentry;
@@ -1607,6 +1607,7 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp
 	}
 
 	if (my_before != NULL) {
+		lease = *my_before;
 		error = lease->fl_lmops->lm_change(my_before, arg);
 		if (!error)
 			*flp = *my_before;
@@ -1630,11 +1631,14 @@ static int generic_add_lease(struct file *filp, long arg, struct file_lock **flp
 	smp_mb();
 	error = check_conflicting_open(dentry, arg);
 	if (error)
-		locks_unlink_lock(before);
+		goto out_unlink;
 out:
 	if (is_deleg)
 		mutex_unlock(&inode->i_mutex);
 	return error;
+out_unlink:
+	locks_unlink_lock(before);
+	goto out;
 }
 
 static int generic_delete_lease(struct file *filp)
@@ -1658,13 +1662,15 @@ static int generic_delete_lease(struct file *filp)
  *	@filp: file pointer
  *	@arg: type of lease to obtain
  *	@flp: input - file_lock to use, output - file_lock inserted
+ *	@aux: auxillary data for lm_setup
  *
  *	The (input) flp->fl_lmops->lm_break function is required
  *	by break_lease().
  *
  *	Called with inode->i_lock held.
  */
-int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
+int generic_setlease(struct file *filp, long arg, struct file_lock **flp,
+			void **aux)
 {
 	struct dentry *dentry = filp->f_path.dentry;
 	struct inode *inode = dentry->d_inode;
@@ -1689,19 +1695,20 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
 			WARN_ON_ONCE(1);
 			return -ENOLCK;
 		}
-		return generic_add_lease(filp, arg, flp);
+		return generic_add_lease(filp, arg, flp, aux);
 	default:
 		return -EINVAL;
 	}
 }
 EXPORT_SYMBOL(generic_setlease);
 
-static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
+static int
+__vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **aux)
 {
 	if (filp->f_op->setlease)
-		return filp->f_op->setlease(filp, arg, lease);
+		return filp->f_op->setlease(filp, arg, lease, aux);
 	else
-		return generic_setlease(filp, arg, lease);
+		return generic_setlease(filp, arg, lease, aux);
 }
 
 /**
@@ -1709,6 +1716,7 @@ static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
  * @filp: file pointer
  * @arg: type of lease to obtain
  * @lease: file_lock to use when adding a lease
+ * @aux: auxillary info for lm_setup when adding a lease
  *
  * Call this to establish a lease on the file. The "lease" argument is not
  * used for F_UNLCK requests and may be NULL. For commands that set or alter
@@ -1724,13 +1732,14 @@ static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
  * this for leases held by processes on this node.
  */
 
-int vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
+int
+vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **aux)
 {
 	struct inode *inode = file_inode(filp);
 	int error;
 
 	spin_lock(&inode->i_lock);
-	error = __vfs_setlease(filp, arg, lease);
+	error = __vfs_setlease(filp, arg, lease, aux);
 	spin_unlock(&inode->i_lock);
 
 	return error;
@@ -1755,7 +1764,7 @@ static int do_fcntl_add_lease(unsigned int fd, struct file *filp, long arg)
 	}
 	ret = fl;
 	spin_lock(&inode->i_lock);
-	error = __vfs_setlease(filp, arg, &ret);
+	error = __vfs_setlease(filp, arg, &ret, NULL);
 	if (error)
 		goto out_unlock;
 	if (ret == fl)
@@ -1793,7 +1802,7 @@ out_unlock:
 int fcntl_setlease(unsigned int fd, struct file *filp, long arg)
 {
 	if (arg == F_UNLCK)
-		return vfs_setlease(filp, F_UNLCK, NULL);
+		return vfs_setlease(filp, F_UNLCK, NULL, NULL);
 	return do_fcntl_add_lease(fd, filp, arg);
 }
 
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 524dd80d1898..7221022232d9 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -895,7 +895,7 @@ EXPORT_SYMBOL_GPL(nfs_flock);
  * There is no protocol support for leases, so we have no way to implement
  * them correctly in the face of opens by other clients.
  */
-int nfs_setlease(struct file *file, long arg, struct file_lock **fl)
+int nfs_setlease(struct file *file, long arg, struct file_lock **fl, void **aux)
 {
 	dprintk("NFS: setlease(%pD2, arg=%ld)\n", file, arg);
 	return -EINVAL;
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 9056622d2230..dcdc83072c10 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -346,7 +346,7 @@ int nfs_file_release(struct inode *, struct file *);
 int nfs_lock(struct file *, int, struct file_lock *);
 int nfs_flock(struct file *, int, struct file_lock *);
 int nfs_check_flags(int);
-int nfs_setlease(struct file *, long, struct file_lock **);
+int nfs_setlease(struct file *, long, struct file_lock **, void **);
 
 /* inode.c */
 extern struct workqueue_struct *nfsiod_workqueue;
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index d0a6e8e022a2..d964a41c9151 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -683,7 +683,7 @@ static void nfs4_put_deleg_lease(struct nfs4_file *fp)
 	if (!fp->fi_deleg_file)
 		return;
 	if (atomic_dec_and_test(&fp->fi_delegees)) {
-		vfs_setlease(fp->fi_deleg_file, F_UNLCK, NULL);
+		vfs_setlease(fp->fi_deleg_file, F_UNLCK, NULL, NULL);
 		fput(fp->fi_deleg_file);
 		fp->fi_deleg_file = NULL;
 	}
@@ -3788,7 +3788,7 @@ static int nfs4_setlease(struct nfs4_delegation *dp)
 	}
 	fl->fl_file = filp;
 	ret = fl;
-	status = vfs_setlease(filp, fl->fl_type, &ret);
+	status = vfs_setlease(filp, fl->fl_type, &fl, NULL);
 	if (status) {
 		locks_free_lock(fl);
 		goto out_fput;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 458f733c96bd..2668d054147f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -982,8 +982,8 @@ extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl);
 extern int flock_lock_file_wait(struct file *filp, struct file_lock *fl);
 extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type);
 extern void lease_get_mtime(struct inode *, struct timespec *time);
-extern int generic_setlease(struct file *, long, struct file_lock **);
-extern int vfs_setlease(struct file *, long, struct file_lock **);
+extern int generic_setlease(struct file *, long, struct file_lock **, void **aux);
+extern int vfs_setlease(struct file *, long, struct file_lock **, void **aux);
 extern int lease_modify(struct file_lock **, int);
 #else /* !CONFIG_FILE_LOCKING */
 static inline int fcntl_getlk(struct file *file, unsigned int cmd,
@@ -1100,13 +1100,13 @@ static inline void lease_get_mtime(struct inode *inode, struct timespec *time)
 }
 
 static inline int generic_setlease(struct file *filp, long arg,
-				    struct file_lock **flp)
+				    struct file_lock **flp, void **aux)
 {
 	return -EINVAL;
 }
 
 static inline int vfs_setlease(struct file *filp, long arg,
-			       struct file_lock **lease)
+			       struct file_lock **lease, void **aux)
 {
 	return -EINVAL;
 }
@@ -1494,7 +1494,7 @@ struct file_operations {
 	int (*flock) (struct file *, int, struct file_lock *);
 	ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);
 	ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);
-	int (*setlease)(struct file *, long, struct file_lock **);
+	int (*setlease)(struct file *, long, struct file_lock **, void **);
 	long (*fallocate)(struct file *file, int mode, loff_t offset,
 			  loff_t len);
 	int (*show_fdinfo)(struct seq_file *m, struct file *f);
-- 
1.9.3