On 2024/12/10 14:28, Christian Brauner wrote:
On Tue, Dec 10, 2024 at 02:03:52PM +0000, Juntong Deng wrote:
This patch adds bpf_fget_task() kfunc.
bpf_fget_task() is used to get a pointer to the struct file
corresponding to the task file descriptor. Note that this function
acquires a reference to struct file.
Signed-off-by: Juntong Deng <juntong.deng@xxxxxxxxxxx>
---
fs/bpf_fs_kfuncs.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/fs/bpf_fs_kfuncs.c b/fs/bpf_fs_kfuncs.c
index 3fe9f59ef867..19a9d45c47f9 100644
--- a/fs/bpf_fs_kfuncs.c
+++ b/fs/bpf_fs_kfuncs.c
@@ -152,6 +152,26 @@ __bpf_kfunc int bpf_get_file_xattr(struct file *file, const char *name__str,
return bpf_get_dentry_xattr(dentry, name__str, value_p);
}
+/**
+ * bpf_fget_task() - Get a pointer to the struct file corresponding to
+ * the task file descriptor
+ *
+ * Note that this function acquires a reference to struct file.
+ *
+ * @task: the specified struct task_struct
+ * @fd: the file descriptor
+ *
+ * @returns the corresponding struct file pointer if found,
+ * otherwise returns NULL
+ */
+__bpf_kfunc struct file *bpf_fget_task(struct task_struct *task, unsigned int fd)
+{
+ struct file *file;
+
+ file = fget_task(task, fd);
+ return file;
Why the local variable?
Thanks for your reply.
Uh, I forgot why I wrote it like that.
Yes, I agree that it is redundant.
I will remove it in the next version.
