@@ -4941,6 +4941,128 @@ static int btrfs_uring_encoded_read(struct io_uring_cmd *cmd, unsigned int issue
return ret;
}
+static int btrfs_uring_encoded_write(struct io_uring_cmd *cmd, unsigned int issue_flags)
+{
+ loff_t pos;
+ struct kiocb kiocb;
+ struct file *file;
+ ssize_t ret;
+ void __user *sqe_addr;
+ struct btrfs_uring_encoded_data *data = io_uring_cmd_get_async_data(cmd)->op_data;
+
+ if (!capable(CAP_SYS_ADMIN)) {
+ ret = -EPERM;
+ goto out_acct;
+ }
+
+ file = cmd->file;
+ sqe_addr = u64_to_user_ptr(READ_ONCE(cmd->sqe->addr));
+
+ if (!(file->f_mode & FMODE_WRITE)) {
+ ret = -EBADF;
+ goto out_acct;
+ }
+
+ if (!data) {
+ data = kzalloc(sizeof(*data), GFP_NOFS);
+ if (!data) {
+ ret = -ENOMEM;
+ goto out_acct;
+ }
+
+ io_uring_cmd_get_async_data(cmd)->op_data = data;
+
+ if (issue_flags & IO_URING_F_COMPAT) {
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+ struct btrfs_ioctl_encoded_io_args_32 args32;
+
+ if (copy_from_user(&args32, sqe_addr, sizeof(args32))) {
+ ret = -EFAULT;
+ goto out_acct;
+ }
+ data->args.iov = compat_ptr(args32.iov);
+ data->args.iovcnt = args32.iovcnt;
+ data->args.offset = args32.offset;
+ data->args.flags = args32.flags;
+ data->args.len = args32.len;
+ data->args.unencoded_len = args32.unencoded_len;
+ data->args.unencoded_offset = args32.unencoded_offset;
+ data->args.compression = args32.compression;
+ data->args.encryption = args32.encryption;
+ memcpy(data->args.reserved, args32.reserved,
+ sizeof(data->args.reserved));
+#else
+ ret = -ENOTTY;
+ goto out_acct;
+#endif
+ } else {
+ if (copy_from_user(&data->args, sqe_addr, sizeof(data->args))) {
+ ret = -EFAULT;
+ goto out_acct;
+ }
+ }
+
+ ret = -EINVAL;
+ if (data->args.flags != 0)
+ goto out_acct;
+ if (memchr_inv(data->args.reserved, 0, sizeof(data->args.reserved)))
+ goto out_acct;
+ if (data->args.compression == BTRFS_ENCODED_IO_COMPRESSION_NONE &&
+ data->args.encryption == BTRFS_ENCODED_IO_ENCRYPTION_NONE)
+ goto out_acct;
+ if (data->args.compression >= BTRFS_ENCODED_IO_COMPRESSION_TYPES ||
+ data->args.encryption >= BTRFS_ENCODED_IO_ENCRYPTION_TYPES)
+ goto out_acct;
+ if (data->args.unencoded_offset > data->args.unencoded_len)
+ goto out_acct;
+ if (data->args.len > data->args.unencoded_len - data->args.unencoded_offset)
+ goto out_acct;
+
+ data->iov = data->iovstack;
+ ret = import_iovec(ITER_SOURCE, data->args.iov, data->args.iovcnt,
+ ARRAY_SIZE(data->iovstack), &data->iov,
+ &data->iter);
+ if (ret < 0)
+ goto out_acct;
+
+ if (iov_iter_count(&data->iter) == 0) {
+ ret = 0;
+ goto out_iov;
+ }
+ }
+
+ if (issue_flags & IO_URING_F_NONBLOCK) {
+ ret = -EAGAIN;
+ goto out_acct;
+ }
+
+ pos = data->args.offset;
+ ret = rw_verify_area(WRITE, file, &pos, data->args.len);
+ if (ret < 0)
+ goto out_iov;
+
+ init_sync_kiocb(&kiocb, file);
+ ret = kiocb_set_rw_flags(&kiocb, 0, WRITE);
+ if (ret)
+ goto out_iov;
+ kiocb.ki_pos = pos;
+
+ file_start_write(file);
+
+ ret = btrfs_do_write_iter(&kiocb, &data->iter, &data->args);
+ if (ret > 0)
+ fsnotify_modify(file);
+
+ file_end_write(file);
+out_iov:
+ kfree(data->iov);
+out_acct:
+ if (ret > 0)
+ add_wchar(current, ret);
+ inc_syscw(current);
+ return ret;
+}
+
int btrfs_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
{
switch (cmd->cmd_op) {
@@ -4949,6 +5071,12 @@ int btrfs_uring_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
case BTRFS_IOC_ENCODED_READ_32:
#endif
return btrfs_uring_encoded_read(cmd, issue_flags);
+
+ case BTRFS_IOC_ENCODED_WRITE:
+#if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
+ case BTRFS_IOC_ENCODED_WRITE_32:
+#endif
+ return btrfs_uring_encoded_write(cmd, issue_flags);
}
return -EINVAL;
Add an io_uring interface for encoded writes, with the same parameters as the BTRFS_IOC_ENCODED_WRITE ioctl. As with the encoded reads code, there's a test program for this at https://github.com/maharmstone/io_uring-encoded, and I'll get this worked into an fstest. How io_uring works is that it initially calls btrfs_uring_cmd with the IO_URING_F_NONBLOCK flag set, and if we return -EAGAIN it tries again in a kthread with the flag cleared. Ideally we'd honour this and call try_lock etc., but there's still a lot of work to be done to create non-blocking versions of all the functions in our write path. Instead, just validate the input in btrfs_uring_encoded_write() on the first pass and return -EAGAIN, with a view to properly optimizing the happy path later on. Signed-off-by: Mark Harmstone <maharmstone@fb.com> --- Changelog: * Version 2: switched to using io_uring_cmd_get_async_data, so that we only copy from userspace once fs/btrfs/ioctl.c | 128 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+)