From 89319d31d2d097da8e27fb0e0ae9d532f4f16827 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sun, 30 Oct 2016 11:42:03 -0500 Subject: [PATCH] fs: remove aio_run_iocb Pass the ABI iocb structure to aio_setup_rw and let it handle the non-vectored I/O case as well. With that and a new helper for the AIO return value handling we can now define new aio_read and aio_write helpers that implement reads and writes in a self-contained way without duplicating too much code. Signed-off-by: Christoph Hellwig Signed-off-by: Al Viro --- fs/aio.c | 182 ++++++++++++++++++++++++++++--------------------------- 1 file changed, 94 insertions(+), 88 deletions(-) diff --git a/fs/aio.c b/fs/aio.c index 2a6030af6ba5..c19755187ca5 100644 --- a/fs/aio.c +++ b/fs/aio.c @@ -1392,110 +1392,100 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx) return -EINVAL; } -typedef ssize_t (rw_iter_op)(struct kiocb *, struct iov_iter *); - -static int aio_setup_vectored_rw(int rw, char __user *buf, size_t len, - struct iovec **iovec, - bool compat, - struct iov_iter *iter) +static int aio_setup_rw(int rw, struct iocb *iocb, struct iovec **iovec, + bool vectored, bool compat, struct iov_iter *iter) { + void __user *buf = (void __user *)(uintptr_t)iocb->aio_buf; + size_t len = iocb->aio_nbytes; + + if (!vectored) { + ssize_t ret = import_single_range(rw, buf, len, *iovec, iter); + *iovec = NULL; + return ret; + } #ifdef CONFIG_COMPAT if (compat) - return compat_import_iovec(rw, - (struct compat_iovec __user *)buf, - len, UIO_FASTIOV, iovec, iter); + return compat_import_iovec(rw, buf, len, UIO_FASTIOV, iovec, + iter); #endif - return import_iovec(rw, (struct iovec __user *)buf, - len, UIO_FASTIOV, iovec, iter); + return import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter); } -/* - * aio_run_iocb: - * Performs the initial checks and io submission. - */ -static ssize_t aio_run_iocb(struct kiocb *req, unsigned opcode, - char __user *buf, size_t len, bool compat) +static inline ssize_t aio_ret(struct kiocb *req, ssize_t ret) +{ + switch (ret) { + case -EIOCBQUEUED: + return ret; + case -ERESTARTSYS: + case -ERESTARTNOINTR: + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + /* + * There's no easy way to restart the syscall since other AIO's + * may be already running. Just fail this IO with EINTR. + */ + ret = -EINTR; + /*FALLTHRU*/ + default: + aio_complete(req, ret, 0); + return 0; + } +} + +static ssize_t aio_read(struct kiocb *req, struct iocb *iocb, bool vectored, + bool compat) { struct file *file = req->ki_filp; - ssize_t ret; - int rw; - fmode_t mode; - rw_iter_op *iter_op; struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; struct iov_iter iter; + ssize_t ret; - switch (opcode) { - case IOCB_CMD_PREAD: - case IOCB_CMD_PREADV: - mode = FMODE_READ; - rw = READ; - iter_op = file->f_op->read_iter; - goto rw_common; - - case IOCB_CMD_PWRITE: - case IOCB_CMD_PWRITEV: - mode = FMODE_WRITE; - rw = WRITE; - iter_op = file->f_op->write_iter; - goto rw_common; -rw_common: - if (unlikely(!(file->f_mode & mode))) - return -EBADF; - - if (!iter_op) - return -EINVAL; - - if (opcode == IOCB_CMD_PREADV || opcode == IOCB_CMD_PWRITEV) - ret = aio_setup_vectored_rw(rw, buf, len, - &iovec, compat, &iter); - else { - ret = import_single_range(rw, buf, len, iovec, &iter); - iovec = NULL; - } - if (!ret) - ret = rw_verify_area(rw, file, &req->ki_pos, - iov_iter_count(&iter)); - if (ret < 0) { - kfree(iovec); - return ret; - } - - get_file(file); - if (rw == WRITE) - file_start_write(file); + if (unlikely(!(file->f_mode & FMODE_READ))) + return -EBADF; + if (unlikely(!file->f_op->read_iter)) + return -EINVAL; - ret = iter_op(req, &iter); + ret = aio_setup_rw(READ, iocb, &iovec, vectored, compat, &iter); + if (ret) + return ret; + ret = rw_verify_area(READ, file, &req->ki_pos, iov_iter_count(&iter)); + if (!ret) + ret = aio_ret(req, file->f_op->read_iter(req, &iter)); + kfree(iovec); + return ret; +} - if (rw == WRITE) - file_end_write(file); - fput(file); - kfree(iovec); - break; +static ssize_t aio_write(struct kiocb *req, struct iocb *iocb, bool vectored, + bool compat) +{ + struct file *file = req->ki_filp; + struct iovec inline_vecs[UIO_FASTIOV], *iovec = inline_vecs; + struct iov_iter iter; + ssize_t ret; - default: - pr_debug("EINVAL: no operation provided\n"); + if (unlikely(!(file->f_mode & FMODE_WRITE))) + return -EBADF; + if (unlikely(!file->f_op->write_iter)) return -EINVAL; - } - if (ret != -EIOCBQUEUED) { - /* - * There's no easy way to restart the syscall since other AIO's - * may be already running. Just fail this IO with EINTR. - */ - if (unlikely(ret == -ERESTARTSYS || ret == -ERESTARTNOINTR || - ret == -ERESTARTNOHAND || - ret == -ERESTART_RESTARTBLOCK)) - ret = -EINTR; - aio_complete(req, ret, 0); + ret = aio_setup_rw(WRITE, iocb, &iovec, vectored, compat, &iter); + if (ret) + return ret; + ret = rw_verify_area(WRITE, file, &req->ki_pos, iov_iter_count(&iter)); + if (!ret) { + file_start_write(file); + ret = aio_ret(req, file->f_op->write_iter(req, &iter)); + file_end_write(file); } - - return 0; + kfree(iovec); + return ret; } static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, struct iocb *iocb, bool compat) { struct aio_kiocb *req; + struct file *file; ssize_t ret; /* enforce forwards compatibility on users */ @@ -1518,7 +1508,7 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, if (unlikely(!req)) return -EAGAIN; - req->common.ki_filp = fget(iocb->aio_fildes); + req->common.ki_filp = file = fget(iocb->aio_fildes); if (unlikely(!req->common.ki_filp)) { ret = -EBADF; goto out_put_req; @@ -1553,13 +1543,29 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb, req->ki_user_iocb = user_iocb; req->ki_user_data = iocb->aio_data; - ret = aio_run_iocb(&req->common, iocb->aio_lio_opcode, - (char __user *)(unsigned long)iocb->aio_buf, - iocb->aio_nbytes, - compat); - if (ret) - goto out_put_req; + get_file(file); + switch (iocb->aio_lio_opcode) { + case IOCB_CMD_PREAD: + ret = aio_read(&req->common, iocb, false, compat); + break; + case IOCB_CMD_PWRITE: + ret = aio_write(&req->common, iocb, false, compat); + break; + case IOCB_CMD_PREADV: + ret = aio_read(&req->common, iocb, true, compat); + break; + case IOCB_CMD_PWRITEV: + ret = aio_write(&req->common, iocb, true, compat); + break; + default: + pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode); + ret = -EINVAL; + break; + } + fput(file); + if (ret && ret != -EIOCBQUEUED) + goto out_put_req; return 0; out_put_req: put_reqs_available(ctx, 1); -- 2.20.1