Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit af7bd4dc authored by Amir Goldstein's avatar Amir Goldstein Committed by Miklos Szeredi
Browse files

vfs: create vfs helper vfs_tmpfile() 



Factor out some common vfs bits from do_tmpfile()
to be used by overlayfs for concurrent copy up.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarMiklos Szeredi <mszeredi@redhat.com>
parent 7ce7d89f

fs/namei.c

+43 −25
Original line number Diff line number Diff line
@@ -3353,13 +3353,50 @@ static int do_last(struct nameidata *nd, 
	return error;

}



struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag)

{

	static const struct qstr name = QSTR_INIT("/", 1);

	struct dentry *child = NULL;

	struct inode *dir = dentry->d_inode;

	struct inode *inode;

	int error;



	/* we want directory to be writable */

	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);

	if (error)

		goto out_err;

	error = -EOPNOTSUPP;

	if (!dir->i_op->tmpfile)

		goto out_err;

	error = -ENOMEM;

	child = d_alloc(dentry, &name);

	if (unlikely(!child))

		goto out_err;

	error = dir->i_op->tmpfile(dir, child, mode);

	if (error)

		goto out_err;

	error = -ENOENT;

	inode = child->d_inode;

	if (unlikely(!inode))

		goto out_err;

	if (!(open_flag & O_EXCL)) {

		spin_lock(&inode->i_lock);

		inode->i_state |= I_LINKABLE;

		spin_unlock(&inode->i_lock);

	}

	return child;



out_err:

	dput(child);

	return ERR_PTR(error);

}

EXPORT_SYMBOL(vfs_tmpfile);



static int do_tmpfile(struct nameidata *nd, unsigned flags,

		const struct open_flags *op,

		struct file *file, int *opened)

{

	static const struct qstr name = QSTR_INIT("/", 1);

	struct dentry *child;

	struct inode *dir;

	struct path path;

	int error = path_lookupat(nd, flags | LOOKUP_DIRECTORY, &path);

	if (unlikely(error))
@@ -3367,25 +3404,12 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, 
	error = mnt_want_write(path.mnt);

	if (unlikely(error))

		goto out;

	dir = path.dentry->d_inode;

	/* we want directory to be writable */

	error = inode_permission(dir, MAY_WRITE | MAY_EXEC);

	if (error)

		goto out2;

	if (!dir->i_op->tmpfile) {

		error = -EOPNOTSUPP;

		goto out2;

	}

	child = d_alloc(path.dentry, &name);

	if (unlikely(!child)) {

		error = -ENOMEM;

	child = vfs_tmpfile(path.dentry, op->mode, op->open_flag);

	error = PTR_ERR(child);

	if (unlikely(IS_ERR(child)))

		goto out2;

	}

	dput(path.dentry);

	path.dentry = child;

	error = dir->i_op->tmpfile(dir, child, op->mode);

	if (error)

		goto out2;

	audit_inode(nd->name, child, 0);

	/* Don't check for other permissions, the inode was just created */

	error = may_open(&path, 0, op->open_flag);
@@ -3396,14 +3420,8 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, 
	if (error)

		goto out2;

	error = open_check_o_direct(file);

	if (error) {

	if (error)

		fput(file);

	} else if (!(op->open_flag & O_EXCL)) {

		struct inode *inode = file_inode(file);

		spin_lock(&inode->i_lock);

		inode->i_state |= I_LINKABLE;

		spin_unlock(&inode->i_lock);

	}

out2:

	mnt_drop_write(path.mnt);

out:

include/linux/fs.h

+3 −0
Original line number Diff line number Diff line
@@ -1561,6 +1561,9 @@ extern int vfs_unlink(struct inode *, struct dentry *, struct inode **); 
extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int);

extern int vfs_whiteout(struct inode *, struct dentry *);



extern struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode,

				  int open_flag);



/*

 * VFS file helper functions.

 */