[PATCH 06/12] locks: use properly initialized file_lock when unlocking.

[NeilBrown]

Both locks_remove_posix() and locks_remove_flock() use a
struct file_lock without calling locks_init_lock() on it.
This means the various list_heads are not initialized, which
will become a problem with a later patch.

So change them both to initialize properly.  For flock locks,
this involves using flock_make_lock(), and changing it to
allow a file_lock to be passed in, so memory allocation isn't
always needed.

Signed-off-by: NeilBrown <ne...@suse.com>
---
 fs/locks.c |   21 +++++++++------------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/fs/locks.c b/fs/locks.c
index b8f33792a0a6..ea999ce0e93c 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -418,15 +418,15 @@ static inline int flock_translate_cmd(int cmd) {
 
 /* Fill in a file_lock structure with an appropriate FLOCK lock. */
 static struct file_lock *
-flock_make_lock(struct file *filp, unsigned int cmd)
+flock_make_lock(struct file *filp, unsigned int cmd, struct file_lock *fl)
 {
-       struct file_lock *fl;
        int type = flock_translate_cmd(cmd);
 
        if (type < 0)
                return ERR_PTR(type);
        
-       fl = locks_alloc_lock();
+       if (fl == NULL)
+               fl = locks_alloc_lock();
        if (fl == NULL)
                return ERR_PTR(-ENOMEM);
 
@@ -2008,7 +2008,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, 
cmd)
            !(f.file->f_mode & (FMODE_READ|FMODE_WRITE)))
                goto out_putf;
 
-       lock = flock_make_lock(f.file, cmd);
+       lock = flock_make_lock(f.file, cmd, NULL);
        if (IS_ERR(lock)) {
                error = PTR_ERR(lock);
                goto out_putf;
@@ -2483,6 +2483,7 @@ void locks_remove_posix(struct file *filp, fl_owner_t 
owner)
        if (!ctx || list_empty(&ctx->flc_posix))
                return;
 
+       locks_init_lock(&lock);
        lock.fl_type = F_UNLCK;
        lock.fl_flags = FL_POSIX | FL_CLOSE;
        lock.fl_start = 0;
@@ -2506,19 +2507,15 @@ EXPORT_SYMBOL(locks_remove_posix);
 static void
 locks_remove_flock(struct file *filp, struct file_lock_context *flctx)
 {
-       struct file_lock fl = {
-               .fl_owner = filp,
-               .fl_pid = current->tgid,
-               .fl_file = filp,
-               .fl_flags = FL_FLOCK | FL_CLOSE,
-               .fl_type = F_UNLCK,
-               .fl_end = OFFSET_MAX,
-       };
+       struct file_lock fl;
        struct inode *inode = locks_inode(filp);
 
        if (list_empty(&flctx->flc_flock))
                return;
 
+       flock_make_lock(filp, LOCK_UN, &fl);
+       fl.fl_flags |= FL_CLOSE;
+
        if (filp->f_op->flock)
                filp->f_op->flock(filp, F_SETLKW, &fl);
        else