new helper: alloc_file_clone()

alloc_file_clone(old_file, mode, ops): create a new struct file with
->f_path equal to that of old_file.  pipe converted.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2018-06-17 14:15:10 -04:00
parent 152b6372c9
commit 183266f26f
3 changed files with 15 additions and 4 deletions

View File

@ -211,6 +211,17 @@ struct file *alloc_file_pseudo(struct inode *inode, struct vfsmount *mnt,
}
EXPORT_SYMBOL(alloc_file_pseudo);
struct file *alloc_file_clone(struct file *base, int flags,
const struct file_operations *fops)
{
struct file *f = alloc_file(&base->f_path, flags, fops);
if (!IS_ERR(f)) {
path_get(&f->f_path);
f->f_mapping = base->f_mapping;
}
return f;
}
/* the real guts of fput() - releasing the last reference to file
*/
static void __fput(struct file *file)

View File

@ -761,15 +761,13 @@ int create_pipe_files(struct file **res, int flags)
f->private_data = inode->i_pipe;
res[0] = alloc_file(&f->f_path, O_RDONLY | (flags & O_NONBLOCK),
&pipefifo_fops);
res[0] = alloc_file_clone(f, O_RDONLY | (flags & O_NONBLOCK),
&pipefifo_fops);
if (IS_ERR(res[0])) {
put_pipe_info(inode, inode->i_pipe);
fput(f);
return PTR_ERR(res[0]);
}
path_get(&f->f_path);
res[0]->private_data = inode->i_pipe;
res[1] = f;
return 0;

View File

@ -23,6 +23,8 @@ extern struct file *alloc_file(const struct path *, int flags,
const struct file_operations *fop);
extern struct file *alloc_file_pseudo(struct inode *, struct vfsmount *,
const char *, int flags, const struct file_operations *);
extern struct file *alloc_file_clone(struct file *, int flags,
const struct file_operations *);
static inline void fput_light(struct file *file, int fput_needed)
{