renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-21 11:44:01 +08:00
Code

file: Implement task_lookup_fd_rcu

Browse Source 
As a companion to lookup_fd_rcu implement task_lookup_fd_rcu for
querying an arbitrary process about a specific file.

Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200818103713.aw46m7vprsy4vlve@wittgenstein
Link: https://lkml.kernel.org/r/20201120231441.29911-11-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
This commit is contained in:
Eric W. Biederman 2020-11-20 17:14:28 -06:00
parent 460b4f812a
commit 3a879fb380
2 changed files with 17 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
fs/file.c
View File

@ -865,6 +865,21 @@ struct file *fget_task(struct task_struct *task, unsigned int fd)
return file;
}
struct file *task_lookup_fd_rcu(struct task_struct *task, unsigned int fd)
{
/* Must be called with rcu_read_lock held */
struct files_struct *files;
struct file *file = NULL;
task_lock(task);
files = task->files;
if (files)
file = files_lookup_fd_rcu(files, fd);
task_unlock(task);
return file;
}
/*
* Lightweight file lookup - no refcnt increment if fd table isn't shared.
*

2
include/linux/fdtable.h
View File

@ -110,6 +110,8 @@ static inline struct file *lookup_fd_rcu(unsigned int fd)
return files_lookup_fd_rcu(current->files, fd);
}
struct file *task_lookup_fd_rcu(struct task_struct *task, unsigned int fd);
struct task_struct;
struct files_struct *get_files_struct(struct task_struct *);