io_uring: cleanup ->user usage

At this point we're only using it for memory accounting, so there's no
need to have an extra ->limit_mem - we can just set ->user if we do
the accounting, or leave it at NULL if we don't.

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 49a636d291cf47dbcb359aab877d27225ddc7e8d..e62ad6bde569f5deb317917e62cafc13442e573b 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -334,7 +334,6 @@ struct io_ring_ctx {
        struct {
                unsigned int            flags;
                unsigned int            compat: 1;
-               unsigned int            limit_mem: 1;
                unsigned int            cq_overflow_flushed: 1;
                unsigned int            drain_next: 1;
                unsigned int            eventfd_async: 1;
@@ -7230,7 +7229,7 @@ static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
        skb->sk = sk;
 
        nr_files = 0;
-       fpl->user = get_uid(ctx->user);
+       fpl->user = get_uid(current_user());
        for (i = 0; i < nr; i++) {
                struct file *file = io_file_from_index(ctx, i + offset);
 
@@ -7942,7 +7941,7 @@ static inline int __io_account_mem(struct user_struct *user,
 
 static void io_unaccount_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
 {
-       if (ctx->limit_mem)
+       if (ctx->user)
                __io_unaccount_mem(ctx->user, nr_pages);
 
        if (ctx->mm_account)
@@ -7953,7 +7952,7 @@ static int io_account_mem(struct io_ring_ctx *ctx, unsigned long nr_pages)
 {
        int ret;
 
-       if (ctx->limit_mem) {
+       if (ctx->user) {
                ret = __io_account_mem(ctx->user, nr_pages);
                if (ret)
                        return ret;
@@ -9370,7 +9369,6 @@ static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
 static int io_uring_create(unsigned entries, struct io_uring_params *p,
                           struct io_uring_params __user *params)
 {
-       struct user_struct *user = NULL;
        struct io_ring_ctx *ctx;
        struct file *file;
        int ret;
@@ -9412,16 +9410,12 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p,
                p->cq_entries = 2 * p->sq_entries;
        }
 
-       user = get_uid(current_user());
-
        ctx = io_ring_ctx_alloc(p);
-       if (!ctx) {
-               free_uid(user);
+       if (!ctx)
                return -ENOMEM;
-       }
        ctx->compat = in_compat_syscall();
-       ctx->limit_mem = !capable(CAP_IPC_LOCK);
-       ctx->user = user;
+       if (!capable(CAP_IPC_LOCK))
+               ctx->user = get_uid(current_user());
        ctx->sqo_task = current;
 
        /*