scsi: target: file: Don't zero iter before iov_iter_bvec
authorPavel Begunkov <asml.silence@gmail.com>
Sat, 9 Jan 2021 15:53:27 +0000 (15:53 +0000)
committerMartin K. Petersen <martin.petersen@oracle.com>
Wed, 13 Jan 2021 05:09:16 +0000 (00:09 -0500)
iov_iter_bvec() initialises iterators well, no need to pre-zero it
beforehand as done in fd_execute_rw_aio(). Compilers can't optimise it out
and generate extra code for that (confirmed with assembly).

Link: https://lore.kernel.org/r/34cd22d6cec046e3adf402accb1453cc255b9042.1610207523.git.asml.silence@gmail.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
drivers/target/target_core_file.c

index b0cb5b9..d1f887e 100644 (file)
@@ -266,7 +266,7 @@ fd_execute_rw_aio(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
        struct fd_dev *fd_dev = FD_DEV(dev);
        struct file *file = fd_dev->fd_file;
        struct target_core_file_cmd *aio_cmd;
-       struct iov_iter iter = {};
+       struct iov_iter iter;
        struct scatterlist *sg;
        struct bio_vec *bvec;
        ssize_t len = 0;