On Tue, 20 Sept 2022 at 03:51, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> On Mon, Sep 19, 2022 at 04:10:30PM +0200, Miklos Szeredi wrote:
> > This is in preparation for adding tmpfile support to fuse, which requires
> > that the tmpfile creation and opening are done as a single operation.
> >
> > Replace the 'struct dentry *' argument of i_op->tmpfile with
> > 'struct file *'.
> >
> > Call finish_open_simple() as the last thing in ->tmpfile() instances (may be
> > omitted in the error case).
> >
> > Change d_tmpfile() argument to 'struct file *' as well to make callers more
> > readable.
>
> It really needs to add to Documentation/filesystems/porting.
OK. Also updated signature and description in locking.rst and vfs.rst.
> I would prefer to separate tmpfile from mknod in that one. And to hell
> with the last argument in do_hugetlbfs_mknod(). Something like (completely
> untested) patch below as prereq:
>
> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> index f7a5b5124d8a..0b458beb318c 100644
> --- a/fs/hugetlbfs/inode.c
> +++ b/fs/hugetlbfs/inode.c
> @@ -885,33 +885,18 @@ static struct inode *hugetlbfs_get_inode(struct super_block *sb,
> /*
> * File creation. Allocate an inode, and we're done..
> */
> -static int do_hugetlbfs_mknod(struct inode *dir,
> - struct dentry *dentry,
> - umode_t mode,
> - dev_t dev,
> - bool tmpfile)
> +static int hugetlbfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
> + struct dentry *dentry, umode_t mode, dev_t dev)
> {
> struct inode *inode;
> - int error = -ENOSPC;
>
> inode = hugetlbfs_get_inode(dir->i_sb, dir, mode, dev);
> - if (inode) {
> - dir->i_ctime = dir->i_mtime = current_time(dir);
> - if (tmpfile) {
> - d_tmpfile(dentry, inode);
> - } else {
> - d_instantiate(dentry, inode);
> - dget(dentry);/* Extra count - pin the dentry in core */
> - }
> - error = 0;
> - }
> - return error;
> -}
> -
> -static int hugetlbfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
> - struct dentry *dentry, umode_t mode, dev_t dev)
> -{
> - return do_hugetlbfs_mknod(dir, dentry, mode, dev, false);
> + if (!inode)
> + return -ENOSPC;
> + dir->i_ctime = dir->i_mtime = current_time(dir);
> + d_instantiate(dentry, inode);
> + dget(dentry);/* Extra count - pin the dentry in core */
> + return 0;
> }
>
> static int hugetlbfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
> @@ -935,7 +920,14 @@ static int hugetlbfs_tmpfile(struct user_namespace *mnt_userns,
> struct inode *dir, struct dentry *dentry,
> umode_t mode)
> {
> - return do_hugetlbfs_mknod(dir, dentry, mode | S_IFREG, 0, true);
> + struct inode *inode;
> +
> + inode = hugetlbfs_get_inode(dir->i_sb, dir, mode | S_IFREG, 0);
> + if (!inode)
> + return -ENOSPC;
> + dir->i_ctime = dir->i_mtime = current_time(dir);
> + d_tmpfile(dentry, inode);
> + return 0;
> }
>
> static int hugetlbfs_symlink(struct user_namespace *mnt_userns,
Added with your authorship and signoff.
Thanks,
Miklos
