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| author | Eric W. Biederman <ebiederm@xmission.com> | 2020-11-21 00:14:28 +0100 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-12-10 19:40:10 +0100 |
| commit | 3a879fb38082125cc0d8aa89b70c7f3a7cdf584b (patch) | |
| tree | bd61b89ba93e2810adc3c6bd8c44530e4a020c48 /fs | |
| parent | file: Rename fcheck lookup_fd_rcu (diff) | |
| download | linux-3a879fb38082125cc0d8aa89b70c7f3a7cdf584b.tar.xz linux-3a879fb38082125cc0d8aa89b70c7f3a7cdf584b.zip | |
file: Implement task_lookup_fd_rcu
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>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/file.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/fs/file.c b/fs/file.c index 5861c4f89419..6448523ca29e 100644 --- a/fs/file.c +++ b/fs/file.c @@ -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. * |