pid: add pidfd_prepare()

Add a new helper that allows to reserve a pidfd and allocates a new
pidfd file that stashes the provided struct pid. This will allow us to
remove places that either open code this function or that call
pidfd_create() but then have to call close_fd() because there are still
failure points after pidfd_create() has been called.

Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230327-pidfd-file-api-v1-1-5c0e9a3158e4@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner
2023-03-27 20:22:51 +02:00
parent 197b6b60ae
commit 6ae930d9db
3 changed files with 93 additions and 12 deletions

View File

@@ -80,6 +80,7 @@ extern struct pid *pidfd_pid(const struct file *file);
struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags);
struct task_struct *pidfd_get_task(int pidfd, unsigned int *flags);
int pidfd_create(struct pid *pid, unsigned int flags);
int pidfd_prepare(struct pid *pid, unsigned int flags, struct file **ret);
static inline struct pid *get_pid(struct pid *pid)
{