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

["J. Bruce Fields" <bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org>]

On Sat, Aug 23, 2014 at 10:41:14AM -0400, Jeff Layton wrote:
> 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;

What's this doing in this patch?

--b.

>  		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
> 
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