diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2020-11-20 17:14:41 -0600 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2020-12-10 12:42:59 -0600 |
| commit | fa67bf885e5211c7dce9514ef2877212c0a5e09e (patch) | |
| tree | 8390573b7ab598a4ddb548f9d2ede8f3ec7bbd2f | |
| parent | 9fe83c43e71cdb8e5b9520bcb98706a2b3c680c8 (diff) | |
file: Remove get_files_struct
When discussing[1] exec and posix file locks it was realized that none
of the callers of get_files_struct fundamentally needed to call
get_files_struct, and that by switching them to helper functions
instead it will both simplify their code and remove unnecessary
increments of files_struct.count. Those unnecessary increments can
result in exec unnecessarily unsharing files_struct which breaking
posix locks, and it can result in fget_light having to fallback to
fget reducing system performance.
Now that get_files_struct has no more users and can not cause the
problems for posix file locking and fget_light remove get_files_struct
so that it does not gain any new users.
[1] https://lkml.kernel.org/r/20180915160423.GA31461@redhat.com
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
v1: https://lkml.kernel.org/r/20200817220425.9389-13-ebiederm@xmission.com
Link: https://lkml.kernel.org/r/20201120231441.29911-24-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| -rw-r--r-- | fs/file.c | 13 | ||||
| -rw-r--r-- | include/linux/fdtable.h | 1 |
2 files changed, 0 insertions, 14 deletions
diff --git a/fs/file.c b/fs/file.c index 947ac6d5602f..412033d8cfdf 100644 --- a/fs/file.c +++ b/fs/file.c @@ -411,19 +411,6 @@ static struct fdtable *close_files(struct files_struct * files) return fdt; } -struct files_struct *get_files_struct(struct task_struct *task) -{ - struct files_struct *files; - - task_lock(task); - files = task->files; - if (files) - atomic_inc(&files->count); - task_unlock(task); - - return files; -} - void put_files_struct(struct files_struct *files) { if (atomic_dec_and_test(&files->count)) { diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h index 4ed3589f9294..d0e78174874a 100644 --- a/include/linux/fdtable.h +++ b/include/linux/fdtable.h @@ -115,7 +115,6 @@ struct file *task_lookup_next_fd_rcu(struct task_struct *task, unsigned int *fd) struct task_struct; -struct files_struct *get_files_struct(struct task_struct *); void put_files_struct(struct files_struct *fs); int unshare_files(void); struct files_struct *dup_fd(struct files_struct *, unsigned, int *) __latent_entropy; |