io_uring/mock: add sync read/write

Add support for synchronous zero read/write for mock files.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/571f3c9fe688e918256a06a722d3db6ced9ca3d5.1750599274.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/include/uapi/linux/io_uring/mock_file.h b/include/uapi/linux/io_uring/mock_file.h
index 73aca477d5c803be8319bec6ba0b1dcb9f3836e0..de27295bb365c2f42dc53079a41a9a392b8eccc9 100644 (file)
--- a/include/uapi/linux/io_uring/mock_file.h
+++ b/include/uapi/linux/io_uring/mock_file.h
@@ -5,6 +5,7 @@
 
 enum {
        IORING_MOCK_FEAT_CMD_COPY,
+       IORING_MOCK_FEAT_RW_ZERO,
 
        IORING_MOCK_FEAT_END,
 };
@@ -17,7 +18,8 @@ struct io_uring_mock_probe {
 struct io_uring_mock_create {
        __u32           out_fd;
        __u32           flags;
-       __u64           __resv[15];
+       __u64           file_size;
+       __u64           __resv[14];
 };
 
 enum {

diff --git a/io_uring/mock_file.c b/io_uring/mock_file.c
index 8285393f4a5b7a24587afe6b69032b6982e0d50a..90160ccb50f0711b9a64c5ee447b510486a34b19 100644 (file)
--- a/io_uring/mock_file.c
+++ b/io_uring/mock_file.c
@@ -9,6 +9,10 @@
 #include <linux/io_uring_types.h>
 #include <uapi/linux/io_uring/mock_file.h>
 
+struct io_mock_file {
+       size_t size;
+};
+
 #define IO_VALID_COPY_CMD_FLAGS                IORING_MOCK_COPY_FROM
 
 static int io_copy_regbuf(struct iov_iter *reg_iter, void __user *ubuf)
@@ -82,18 +86,59 @@ static int io_mock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
        return -ENOTSUPP;
 }
 
+static ssize_t io_mock_read_iter(struct kiocb *iocb, struct iov_iter *to)
+{
+       struct io_mock_file *mf = iocb->ki_filp->private_data;
+       size_t len = iov_iter_count(to);
+
+       if (iocb->ki_pos + len > mf->size)
+               return -EINVAL;
+       return iov_iter_zero(len, to);
+}
+
+static ssize_t io_mock_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+       struct io_mock_file *mf = iocb->ki_filp->private_data;
+       size_t len = iov_iter_count(from);
+
+       if (iocb->ki_pos + len > mf->size)
+               return -EINVAL;
+       iov_iter_advance(from, len);
+       return len;
+}
+
+static loff_t io_mock_llseek(struct file *file, loff_t offset, int whence)
+{
+       struct io_mock_file *mf = file->private_data;
+
+       return fixed_size_llseek(file, offset, whence, mf->size);
+}
+
+static int io_mock_release(struct inode *inode, struct file *file)
+{
+       struct io_mock_file *mf = file->private_data;
+
+       kfree(mf);
+       return 0;
+}
+
 static const struct file_operations io_mock_fops = {
        .owner          = THIS_MODULE,
+       .release        = io_mock_release,
        .uring_cmd      = io_mock_cmd,
+       .read_iter      = io_mock_read_iter,
+       .write_iter     = io_mock_write_iter,
+       .llseek         = io_mock_llseek,
 };
 
 static int io_create_mock_file(struct io_uring_cmd *cmd, unsigned int issue_flags)
 {
        const struct io_uring_sqe *sqe = cmd->sqe;
        struct io_uring_mock_create mc, __user *uarg;
+       struct io_mock_file *mf = NULL;
        struct file *file = NULL;
        size_t uarg_size;
-       int fd, ret;
+       int fd = -1, ret;
 
        /*
         * It's a testing only driver that allows exercising edge cases
@@ -114,18 +159,28 @@ static int io_create_mock_file(struct io_uring_cmd *cmd, unsigned int issue_flag
                return -EFAULT;
        if (!mem_is_zero(mc.__resv, sizeof(mc.__resv)) || mc.flags)
                return -EINVAL;
+       if (mc.file_size > SZ_1G)
+               return -EINVAL;
+       mf = kzalloc(sizeof(*mf), GFP_KERNEL_ACCOUNT);
+       if (!mf)
+               return -ENOMEM;
 
-       fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
+       ret = fd = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
        if (fd < 0)
-               return fd;
+               goto fail;
 
+       mf->size = mc.file_size;
        file = anon_inode_create_getfile("[io_uring_mock]", &io_mock_fops,
-                                        NULL, O_RDWR | O_CLOEXEC, NULL);
+                                        mf, O_RDWR | O_CLOEXEC, NULL);
        if (IS_ERR(file)) {
                ret = PTR_ERR(file);
                goto fail;
        }
 
+       file->f_mode |= FMODE_READ | FMODE_CAN_READ |
+                       FMODE_WRITE | FMODE_CAN_WRITE |
+                       FMODE_LSEEK;
+
        mc.out_fd = fd;
        if (copy_to_user(uarg, &mc, uarg_size)) {
                fput(file);
@@ -136,7 +191,9 @@ static int io_create_mock_file(struct io_uring_cmd *cmd, unsigned int issue_flag
        fd_install(fd, file);
        return 0;
 fail:
-       put_unused_fd(fd);
+       if (fd >= 0)
+               put_unused_fd(fd);
+       kfree(mf);
        return ret;
 }