Commit c8ccbe03 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Al Viro
Browse files

fuse: implement i_op->atomic_open() 



Add an ->atomic_open implementation which replaces the atomic open+create
operation implemented via ->create.  No functionality is changed.

Signed-off-by: default avatarMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent eda72afb

fs/fuse/dir.c

+67 −27
Original line number Diff line number Diff line
@@ -369,8 +369,9 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry, 
 * If the filesystem doesn't support this, then fall back to separate

 * 'mknod' + 'open' requests.

 */

static int fuse_create_open(struct inode *dir, struct dentry *entry,

			    umode_t mode, struct nameidata *nd)

static struct file *fuse_create_open(struct inode *dir, struct dentry *entry,

				     struct opendata *od, unsigned flags,

				     umode_t mode)

{

	int err;

	struct inode *inode;
@@ -382,14 +383,11 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, 
	struct fuse_entry_out outentry;

	struct fuse_file *ff;

	struct file *file;

	int flags = nd->intent.open.flags;



	if (fc->no_create)

		return -ENOSYS;



	forget = fuse_alloc_forget();

	err = -ENOMEM;

	if (!forget)

		return -ENOMEM;

		goto out_err;



	req = fuse_get_req(fc);

	err = PTR_ERR(req);
@@ -428,11 +426,8 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, 
	req->out.args[1].value = &outopen;

	fuse_request_send(fc, req);

	err = req->out.h.error;

	if (err) {

		if (err == -ENOSYS)

			fc->no_create = 1;

	if (err)

		goto out_free_ff;

	}



	err = -EIO;

	if (!S_ISREG(outentry.attr.mode) || invalid_nodeid(outentry.nodeid))
@@ -448,20 +443,21 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, 
		flags &= ~(O_CREAT | O_EXCL | O_TRUNC);

		fuse_sync_release(ff, flags);

		fuse_queue_forget(fc, forget, outentry.nodeid, 1);

		return -ENOMEM;

		err = -ENOMEM;

		goto out_err;

	}

	kfree(forget);

	d_instantiate(entry, inode);

	fuse_change_entry_timeout(entry, &outentry);

	fuse_invalidate_attr(dir);

	file = lookup_instantiate_filp(nd, entry, generic_file_open);

	file = finish_open(od, entry, generic_file_open);

	if (IS_ERR(file)) {

		fuse_sync_release(ff, flags);

		return PTR_ERR(file);

	}

	} else {

		file->private_data = fuse_file_get(ff);

		fuse_finish_open(inode, file);

	return 0;

	}

	return file;



out_free_ff:

	fuse_file_free(ff);
@@ -469,7 +465,56 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, 
	fuse_put_request(fc, req);

out_put_forget_req:

	kfree(forget);

	return err;

out_err:

	return ERR_PTR(err);

}



static int fuse_mknod(struct inode *, struct dentry *, umode_t, dev_t);

static struct file *fuse_atomic_open(struct inode *dir, struct dentry *entry,

				     struct opendata *od, unsigned flags,

				     umode_t mode, bool *created)

{

	int err;

	struct fuse_conn *fc = get_fuse_conn(dir);

	struct file *file;

	struct dentry *res = NULL;



	if (d_unhashed(entry)) {

		res = fuse_lookup(dir, entry, NULL);

		if (IS_ERR(res))

			return ERR_CAST(res);



		if (res)

			entry = res;

	}



	if (!(flags & O_CREAT) || entry->d_inode)

		goto no_open;



	/* Only creates */

	*created = true;



	if (fc->no_create)

		goto mknod;



	file = fuse_create_open(dir, entry, od, flags, mode);

	if (PTR_ERR(file) == -ENOSYS) {

		fc->no_create = 1;

		goto mknod;

	}

out_dput:

	dput(res);

	return file;



mknod:

	err = fuse_mknod(dir, entry, mode, 0);

	if (err) {

		file = ERR_PTR(err);

		goto out_dput;

	}

no_open:

	finish_no_open(od, res);

	return NULL;

}



/*
@@ -573,12 +618,6 @@ static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode, 
static int fuse_create(struct inode *dir, struct dentry *entry, umode_t mode,

		       struct nameidata *nd)

{

	if (nd) {

		int err = fuse_create_open(dir, entry, mode, nd);

		if (err != -ENOSYS)

			return err;

		/* Fall back on mknod */

	}

	return fuse_mknod(dir, entry, mode, 0);

}
@@ -1646,6 +1685,7 @@ static const struct inode_operations fuse_dir_inode_operations = { 
	.link		= fuse_link,

	.setattr	= fuse_setattr,

	.create		= fuse_create,

	.atomic_open	= fuse_atomic_open,

	.mknod		= fuse_mknod,

	.permission	= fuse_permission,

	.getattr	= fuse_getattr,