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Commit f82b4b67 authored by Jeff Layton's avatar Jeff Layton
Browse files

locks: move i_lock acquisition into generic_*_lease handlers 



Now that we have a saner internal API for managing leases, we no longer
need to mandate that the inode->i_lock be held over most of the lease
code. Push it down into generic_add_lease and generic_delete_lease.

Signed-off-by: default avatarJeff Layton <jlayton@primarydata.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 1c7dd2ff

Documentation/filesystems/Locking

+4 −2
Original line number Diff line number Diff line
@@ -472,8 +472,6 @@ locking rules: 
	All may block except for ->setlease.

	No VFS locks held on entry except for ->setlease.



->setlease has the file_list_lock held and must not sleep.



->llseek() locking has moved from llseek to the individual llseek

implementations.  If your fs is not using generic_file_llseek, you

need to acquire and release the appropriate locks in your ->llseek().
@@ -496,6 +494,10 @@ components. And there are other reasons why the current interface is a mess... 
->read on directories probably must go away - we should just enforce -EISDIR

in sys_read() and friends.



->setlease operations should call generic_setlease() before or after setting

the lease within the individual filesystem to record the result of the

operation



--------------------------- dquot_operations -------------------------------

prototypes:

	int (*write_dquot) (struct dquot *);

Documentation/filesystems/vfs.txt

+3 −2
Original line number Diff line number Diff line
@@ -895,8 +895,9 @@ otherwise noted. 
  splice_read: called by the VFS to splice data from file to a pipe. This

	       method is used by the splice(2) system call



  setlease: called by the VFS to set or release a file lock lease.

	    setlease has the file_lock_lock held and must not sleep.

  setlease: called by the VFS to set or release a file lock lease. setlease

	    implementations should call generic_setlease to record or remove

	    the lease in the inode after setting it.



  fallocate: called by the VFS to preallocate blocks or punch a hole.

fs/locks.c

+9 −12
Original line number Diff line number Diff line
@@ -1330,6 +1330,8 @@ static void time_out_leases(struct inode *inode) 
	struct file_lock **before;

	struct file_lock *fl;



	lockdep_assert_held(&inode->i_lock);



	before = &inode->i_flock;

	while ((fl = *before) && IS_LEASE(fl) && lease_breaking(fl)) {

		trace_time_out_leases(inode, fl);
@@ -1590,6 +1592,8 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr 
		return -EINVAL;

	}



	spin_lock(&inode->i_lock);

	time_out_leases(inode);

	error = check_conflicting_open(dentry, arg);

	if (error)

		goto out;
@@ -1655,6 +1659,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr 
	if (lease->fl_lmops->lm_setup)

		lease->fl_lmops->lm_setup(lease, priv);

out:

	spin_unlock(&inode->i_lock);

	if (is_deleg)

		mutex_unlock(&inode->i_mutex);

	if (!error && !my_before)
@@ -1672,6 +1677,7 @@ static int generic_delete_lease(struct file *filp) 
	struct dentry *dentry = filp->f_path.dentry;

	struct inode *inode = dentry->d_inode;



	spin_lock(&inode->i_lock);

	for (before = &inode->i_flock;

			((fl = *before) != NULL) && IS_LEASE(fl);

			before = &fl->fl_next) {
@@ -1681,6 +1687,7 @@ static int generic_delete_lease(struct file *filp) 
	trace_generic_delete_lease(inode, fl);

	if (fl)

		error = fl->fl_lmops->lm_change(before, F_UNLCK);

	spin_unlock(&inode->i_lock);

	return error;

}
@@ -1694,8 +1701,6 @@ static int generic_delete_lease(struct file *filp) 
 *

 *	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,

			void **priv)
@@ -1712,8 +1717,6 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp, 
	if (error)

		return error;



	time_out_leases(inode);



	switch (arg) {

	case F_UNLCK:

		return generic_delete_lease(filp);
@@ -1750,16 +1753,10 @@ EXPORT_SYMBOL(generic_setlease); 
int

vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)

{

	struct inode *inode = file_inode(filp);

	int error;



	spin_lock(&inode->i_lock);

	if (filp->f_op->setlease)

		error = filp->f_op->setlease(filp, arg, lease, priv);

		return filp->f_op->setlease(filp, arg, lease, priv);

	else

		error = generic_setlease(filp, arg, lease, priv);

	spin_unlock(&inode->i_lock);

	return error;

		return generic_setlease(filp, arg, lease, priv);

}

EXPORT_SYMBOL_GPL(vfs_setlease);