Call io_async_list_note at the end if -EAGAIN is going to be returned; we need iov_count for that, which we have (almost) at the same time as we need to free iovec.
Instead of using a second return value reset the normal one after passing it to io_rw_done. Unless rw_verify_area returns -EAGAIN this shouldn't result in different behavior. This change should make it easier to punt a request to the workers by returning -EAGAIN and still calling io_async_list_note if needed. Signed-off-by: Stefan Bühler <[email protected]> --- fs/io_uring.c | 89 ++++++++++++++++++++++----------------------------- 1 file changed, 39 insertions(+), 50 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 84efb8956734..52e435a72b6f 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1062,26 +1062,24 @@ static int io_read(struct io_kiocb *req, const struct sqe_submit *s, ret = io_import_iovec(req->ctx, READ, s, &iovec, &iter); if (ret) return ret; - iov_count = iov_iter_count(&iter); + ret = rw_verify_area(READ, file, &kiocb->ki_pos, iov_count); - if (!ret) { - ssize_t ret2; + if (ret) + goto out_free; - /* Catch -EAGAIN return for forced non-blocking submission */ - ret2 = call_read_iter(file, kiocb, &iter); - if (!force_nonblock || ret2 != -EAGAIN) { - io_rw_done(kiocb, ret2); - } else { - /* - * If ->needs_lock is true, we're already in async - * context. - */ - if (!s->needs_lock) - io_async_list_note(READ, req, iov_count); - ret = -EAGAIN; - } + /* Passthrough -EAGAIN return for forced non-blocking submission */ + ret = call_read_iter(file, kiocb, &iter); + if (!(force_nonblock && ret == -EAGAIN)) { + io_rw_done(kiocb, ret); + ret = 0; } + +out_free: + /* If ->needs_lock is true, we're already in async context. */ + if (ret == -EAGAIN && !s->needs_lock) + io_async_list_note(READ, req, iov_count); + kfree(iovec); return ret; } @@ -1109,50 +1107,41 @@ static int io_write(struct io_kiocb *req, const struct sqe_submit *s, ret = io_import_iovec(req->ctx, WRITE, s, &iovec, &iter); if (ret) return ret; - iov_count = iov_iter_count(&iter); ret = -EAGAIN; - if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT)) { - /* If ->needs_lock is true, we're already in async context. */ - if (!s->needs_lock) - io_async_list_note(WRITE, req, iov_count); + if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT)) goto out_free; - } ret = rw_verify_area(WRITE, file, &kiocb->ki_pos, iov_count); - if (!ret) { - ssize_t ret2; + if (ret) + goto out_free; - /* - * Open-code file_start_write here to grab freeze protection, - * which will be released by another thread in - * io_complete_rw(). Fool lockdep by telling it the lock got - * released so that it doesn't complain about the held lock when - * we return to userspace. - */ - if (S_ISREG(file_inode(file)->i_mode)) { - __sb_start_write(file_inode(file)->i_sb, - SB_FREEZE_WRITE, true); - __sb_writers_release(file_inode(file)->i_sb, - SB_FREEZE_WRITE); - } - kiocb->ki_flags |= IOCB_WRITE; + /* + * Open-code file_start_write here to grab freeze protection, + * which will be released by another thread in + * io_complete_rw(). Fool lockdep by telling it the lock got + * released so that it doesn't complain about the held lock when + * we return to userspace. + */ + if (S_ISREG(file_inode(file)->i_mode)) { + __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true); + __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE); + } + kiocb->ki_flags |= IOCB_WRITE; - ret2 = call_write_iter(file, kiocb, &iter); - if (!force_nonblock || ret2 != -EAGAIN) { - io_rw_done(kiocb, ret2); - } else { - /* - * If ->needs_lock is true, we're already in async - * context. - */ - if (!s->needs_lock) - io_async_list_note(WRITE, req, iov_count); - ret = -EAGAIN; - } + /* Passthrough -EAGAIN return for forced non-blocking submission */ + ret = call_write_iter(file, kiocb, &iter); + if (!(force_nonblock && ret == -EAGAIN)) { + io_rw_done(kiocb, ret); + ret = 0; } + out_free: + /* If ->needs_lock is true, we're already in async context. */ + if (ret == -EAGAIN && !s->needs_lock) + io_async_list_note(WRITE, req, iov_count); + kfree(iovec); return ret; } -- 2.20.1
