From 4017eb91a9e79bbb5d14868c207436f4a6a0af50 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Thu, 22 Oct 2020 14:14:12 -0600 Subject: io_uring: make loop_rw_iter() use original user supplied pointers We jump through a hoop for fixed buffers, where we first map these to a bvec(), then kmap() the bvec to obtain the pointer we copy to/from. This was always a bit ugly, and with the set_fs changes, it ends up being practically problematic as well. There's no need to jump through these hoops, just use the original user pointers and length for the non iter based read/write. Signed-off-by: Jens Axboe --- fs/io_uring.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) (limited to 'fs') diff --git a/fs/io_uring.c b/fs/io_uring.c index 45320458a5f9..d40717f8647b 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -790,7 +790,7 @@ static const struct io_op_def io_op_defs[] = { .unbound_nonreg_file = 1, .pollin = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_BLKCG, + .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_MM, }, [IORING_OP_WRITE_FIXED] = { .needs_file = 1, @@ -798,7 +798,8 @@ static const struct io_op_def io_op_defs[] = { .unbound_nonreg_file = 1, .pollout = 1, .async_size = sizeof(struct io_async_rw), - .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE, + .work_flags = IO_WQ_WORK_BLKCG | IO_WQ_WORK_FSIZE | + IO_WQ_WORK_MM, }, [IORING_OP_POLL_ADD] = { .needs_file = 1, @@ -3115,9 +3116,10 @@ static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb) * For files that don't have ->read_iter() and ->write_iter(), handle them * by looping over ->read() or ->write() manually. */ -static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb, - struct iov_iter *iter) +static ssize_t loop_rw_iter(int rw, struct io_kiocb *req, struct iov_iter *iter) { + struct kiocb *kiocb = &req->rw.kiocb; + struct file *file = req->file; ssize_t ret = 0; /* @@ -3137,11 +3139,8 @@ static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb, if (!iov_iter_is_bvec(iter)) { iovec = iov_iter_iovec(iter); } else { - /* fixed buffers import bvec */ - iovec.iov_base = kmap(iter->bvec->bv_page) - + iter->iov_offset; - iovec.iov_len = min(iter->count, - iter->bvec->bv_len - iter->iov_offset); + iovec.iov_base = u64_to_user_ptr(req->rw.addr); + iovec.iov_len = req->rw.len; } if (rw == READ) { @@ -3152,9 +3151,6 @@ static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb, iovec.iov_len, io_kiocb_ppos(kiocb)); } - if (iov_iter_is_bvec(iter)) - kunmap(iter->bvec->bv_page); - if (nr < 0) { if (!ret) ret = nr; @@ -3163,6 +3159,8 @@ static ssize_t loop_rw_iter(int rw, struct file *file, struct kiocb *kiocb, ret += nr; if (nr != iovec.iov_len) break; + req->rw.len -= nr; + req->rw.addr += nr; iov_iter_advance(iter, nr); } @@ -3352,7 +3350,7 @@ static int io_iter_do_read(struct io_kiocb *req, struct iov_iter *iter) if (req->file->f_op->read_iter) return call_read_iter(req->file, &req->rw.kiocb, iter); else if (req->file->f_op->read) - return loop_rw_iter(READ, req->file, &req->rw.kiocb, iter); + return loop_rw_iter(READ, req, iter); else return -EINVAL; } @@ -3543,7 +3541,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock, if (req->file->f_op->write_iter) ret2 = call_write_iter(req->file, kiocb, iter); else if (req->file->f_op->write) - ret2 = loop_rw_iter(WRITE, req->file, kiocb, iter); + ret2 = loop_rw_iter(WRITE, req, iter); else ret2 = -EINVAL; -- cgit v1.2.3