Revert "io_uring: only allow submit from owning task"

This ends up being too restrictive for tasks that willingly fork and
share the ring between forks. Andres reports that this breaks his
postgresql work. Since we're close to 5.5 release, revert this change
for now.

Cc: stable@vger.kernel.org
Fixes: 44d282796f81 ("io_uring: only allow submit from owning task")
Reported-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 5953d7f13690188d75035d49fdaf9c889cb755a4..e5b502091804de41273f10fb8111bb36d4c0e0d1 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5161,12 +5161,6 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
        } else if (to_submit) {
                struct mm_struct *cur_mm;
 
-               if (current->mm != ctx->sqo_mm ||
-                   current_cred() != ctx->creds) {
-                       ret = -EPERM;
-                       goto out;
-               }
-
                to_submit = min(to_submit, ctx->sq_entries);
                mutex_lock(&ctx->uring_lock);
                /* already have mm, so io_submit_sqes() won't try to grab it */