io_uring: add generic path for rsrc update

Extract some common parts for rsrc update, will be used reg buffers
support dynamic (i.e. quiesce-lee) managing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b49c3ff6b9ff0e530295767604fe4de64d349e04.1619356238.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9796998ef10003b947f469e20b6f0d573d5743b1..86a957d1059b3701e6fb3d209ef37c4daea1e4e5 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1035,9 +1035,9 @@ static void io_dismantle_req(struct io_kiocb *req);
 static void io_put_task(struct task_struct *task, int nr);
 static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req);
 static void io_queue_linked_timeout(struct io_kiocb *req);
-static int __io_sqe_files_update(struct io_ring_ctx *ctx,
-                                struct io_uring_rsrc_update *ip,
-                                unsigned nr_args);
+static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned opcode,
+                                    struct io_uring_rsrc_update *up,
+                                    unsigned nr_args);
 static void io_clean_op(struct io_kiocb *req);
 static struct file *io_file_get(struct io_submit_state *state,
                                struct io_kiocb *req, int fd, bool fixed);
@@ -5824,7 +5824,8 @@ static int io_files_update(struct io_kiocb *req, unsigned int issue_flags)
        up.data = req->rsrc_update.arg;
 
        mutex_lock(&ctx->uring_lock);
-       ret = __io_sqe_files_update(ctx, &up, req->rsrc_update.nr_args);
+       ret = __io_register_rsrc_update(ctx, IORING_REGISTER_FILES_UPDATE,
+                                       &up, req->rsrc_update.nr_args);
        mutex_unlock(&ctx->uring_lock);
 
        if (ret < 0)
@@ -7726,25 +7727,20 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
                                 struct io_uring_rsrc_update *up,
                                 unsigned nr_args)
 {
+       __s32 __user *fds = u64_to_user_ptr(up->data);
        struct io_rsrc_data *data = ctx->file_data;
        struct io_fixed_file *file_slot;
        struct file *file;
-       __s32 __user *fds;
-       int fd, i, err;
-       __u32 done;
+       int fd, i, err = 0;
+       unsigned int done;
        bool needs_switch = false;
 
-       if (check_add_overflow(up->offset, nr_args, &done))
-               return -EOVERFLOW;
-       if (done > ctx->nr_user_files)
+       if (!ctx->file_data)
+               return -ENXIO;
+       if (up->offset + nr_args > ctx->nr_user_files)
                return -EINVAL;
-       err = io_rsrc_node_switch_start(ctx);
-       if (err)
-               return err;
 
-       fds = u64_to_user_ptr(up->data);
        for (done = 0; done < nr_args; done++) {
-               err = 0;
                if (copy_from_user(&fd, &fds[done], sizeof(fd))) {
                        err = -EFAULT;
                        break;
@@ -7798,23 +7794,6 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
        return done ? done : err;
 }
 
-static int io_sqe_files_update(struct io_ring_ctx *ctx, void __user *arg,
-                              unsigned nr_args)
-{
-       struct io_uring_rsrc_update up;
-
-       if (!ctx->file_data)
-               return -ENXIO;
-       if (!nr_args)
-               return -EINVAL;
-       if (copy_from_user(&up, arg, sizeof(up)))
-               return -EFAULT;
-       if (up.resv)
-               return -EINVAL;
-
-       return __io_sqe_files_update(ctx, &up, nr_args);
-}
-
 static struct io_wq_work *io_free_work(struct io_wq_work *work)
 {
        struct io_kiocb *req = container_of(work, struct io_kiocb, work);
@@ -9730,6 +9709,40 @@ static int io_register_enable_rings(struct io_ring_ctx *ctx)
        return 0;
 }
 
+static int __io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned opcode,
+                                    struct io_uring_rsrc_update *up,
+                                    unsigned nr_args)
+{
+       __u32 tmp;
+       int err;
+
+       if (check_add_overflow(up->offset, nr_args, &tmp))
+               return -EOVERFLOW;
+       err = io_rsrc_node_switch_start(ctx);
+       if (err)
+               return err;
+
+       switch (opcode) {
+       case IORING_REGISTER_FILES_UPDATE:
+               return __io_sqe_files_update(ctx, up, nr_args);
+       }
+       return -EINVAL;
+}
+
+static int io_register_rsrc_update(struct io_ring_ctx *ctx, unsigned opcode,
+                                  void __user *arg, unsigned nr_args)
+{
+       struct io_uring_rsrc_update up;
+
+       if (!nr_args)
+               return -EINVAL;
+       if (copy_from_user(&up, arg, sizeof(up)))
+               return -EFAULT;
+       if (up.resv)
+               return -EINVAL;
+       return __io_register_rsrc_update(ctx, opcode, &up, nr_args);
+}
+
 static bool io_register_op_must_quiesce(int op)
 {
        switch (op) {
@@ -9816,7 +9829,7 @@ static int __io_uring_register(struct io_ring_ctx *ctx, unsigned opcode,
                ret = io_sqe_files_unregister(ctx);
                break;
        case IORING_REGISTER_FILES_UPDATE:
-               ret = io_sqe_files_update(ctx, arg, nr_args);
+               ret = io_register_rsrc_update(ctx, opcode, arg, nr_args);
                break;
        case IORING_REGISTER_EVENTFD:
        case IORING_REGISTER_EVENTFD_ASYNC: