locks: ensure that fl_owner is always initialized properly in flock and lease codepaths

Currently, the fl_owner isn't set for flock locks. Some filesystems use
byte-range locks to simulate flock locks and there is a common idiom in
those that does:

    fl->fl_owner = (fl_owner_t)filp;
    fl->fl_start = 0;
    fl->fl_end = OFFSET_MAX;

Since flock locks are generally "owned" by the open file description,
move this into the common flock lock setup code. The fl_start and fl_end
fields are already set appropriately, so remove the unneeded setting of
that in flock ops in those filesystems as well.

Finally, the lease code also sets the fl_owner as if they were owned by
the process and not the open file description. This is incorrect as
leases have the same ownership semantics as flock locks. Set them the
same way. The lease code doesn't actually use the fl_owner value for
anything, so this is more for consistency's sake than a bugfix.

Reported-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> (Staging portion)
Acked-by: J. Bruce Fields <bfields@fieldses.org>

6 files changed, 5 insertions, 21 deletions

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index d822320..59e3fe3 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -352,9 +352,6 @@ static int v9fs_file_flock_dotl(struct file *filp, int cmd,
 		invalidate_mapping_pages(&inode->i_data, 0, -1);
 	}
 	/* Convert flock to posix lock */
-	fl->fl_owner = (fl_owner_t)filp;
-	fl->fl_start = 0;
-	fl->fl_end = OFFSET_MAX;
 	fl->fl_flags |= FL_POSIX;
 	fl->fl_flags ^= FL_FLOCK;
 
diff --git a/fs/afs/flock.c b/fs/afs/flock.c
index a8cf2cf..4baf1d2 100644
--- a/fs/afs/flock.c
+++ b/fs/afs/flock.c
@@ -555,10 +555,6 @@ int afs_flock(struct file *file, int cmd, struct file_lock *fl)
 		return -ENOLCK;
 
 	/* we're simulating flock() locks using posix locks on the server */
-	fl->fl_owner = (fl_owner_t) file;
-	fl->fl_start = 0;
-	fl->fl_end = OFFSET_MAX;
-
 	if (fl->fl_type == F_UNLCK)
 		return afs_do_unlk(file, fl);
 	return afs_do_setlk(file, fl);
diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c
index 1913988..fbc39c4 100644
--- a/fs/ceph/locks.c
+++ b/fs/ceph/locks.c
@@ -53,10 +53,7 @@ static int ceph_lock_message(u8 lock_type, u16 operation, struct file *file,
 	else
 		length = fl->fl_end - fl->fl_start + 1;
 
-	if (lock_type == CEPH_LOCK_FCNTL)
-		owner = secure_addr(fl->fl_owner);
-	else
-		owner = secure_addr(fl->fl_file);
+	owner = secure_addr(fl->fl_owner);
 
 	dout("ceph_lock_message: rule: %d, op: %d, owner: %llx, pid: %llu, "
 	     "start: %llu, length: %llu, wait: %d, type: %d", (int)lock_type,
@@ -314,10 +311,7 @@ int lock_to_ceph_filelock(struct file_lock *lock,
 	cephlock->length = cpu_to_le64(lock->fl_end - lock->fl_start + 1);
 	cephlock->client = cpu_to_le64(0);
 	cephlock->pid = cpu_to_le64((u64)lock->fl_pid);
-	if (lock->fl_flags & FL_POSIX)
-		cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner));
-	else
-		cephlock->owner = cpu_to_le64(secure_addr(lock->fl_file));
+	cephlock->owner = cpu_to_le64(secure_addr(lock->fl_owner));
 
 	switch (lock->fl_type) {
 	case F_RDLCK:
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 96d513e..f680d2c 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2304,7 +2304,6 @@ static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
 		struct fuse_file *ff = file->private_data;
 
 		/* emulate flock with POSIX locks */
-		fl->fl_owner = (fl_owner_t) file;
 		ff->flock = true;
 		err = fuse_setlk(file, fl, 1);
 	}
diff --git a/fs/locks.c b/fs/locks.c
index e390bd9..77aff89 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -322,6 +322,7 @@ static int flock_make_lock(struct file *filp, struct file_lock **lock,
 		return -ENOMEM;
 
 	fl->fl_file = filp;
+	fl->fl_owner = (fl_owner_t)filp;
 	fl->fl_pid = current->tgid;
 	fl->fl_flags = FL_FLOCK;
 	fl->fl_type = type;
@@ -427,7 +428,7 @@ static int lease_init(struct file *filp, long type, struct file_lock *fl)
 	if (assign_type(fl, type) != 0)
 		return -EINVAL;
 
-	fl->fl_owner = current->files;
+	fl->fl_owner = (fl_owner_t)filp;
 	fl->fl_pid = current->tgid;
 
 	fl->fl_file = filp;
@@ -2316,6 +2317,7 @@ void locks_remove_file(struct file *filp)
 
 	if (filp->f_op->flock) {
 		struct file_lock fl = {
+			.fl_owner = (fl_owner_t)filp,
 			.fl_pid = current->tgid,
 			.fl_file = filp,
 			.fl_flags = FL_FLOCK,
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 284ca90..c1edf73 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -916,10 +916,6 @@ int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
 		is_local = 1;
 
 	/* We're simulating flock() locks using posix locks on the server */
-	fl->fl_owner = (fl_owner_t)filp;
-	fl->fl_start = 0;
-	fl->fl_end = OFFSET_MAX;
-
 	if (fl->fl_type == F_UNLCK)
 		return do_unlk(filp, cmd, fl, is_local);
 	return do_setlk(filp, cmd, fl, is_local);