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aio: move sanity checks and request allocation to io_submit_one()

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makes for somewhat cleaner control flow in __io_submit_one()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2019-03-06 18:24:51 -05:00
parent fa0ca2aee3
commit 7316b49c2a
1 changed files with 53 additions and 66 deletions
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119
fs/aio.c
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@ -1777,35 +1777,12 @@ static int aio_poll(struct aio_kiocb *aiocb, const struct iocb *iocb)
}
static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
struct iocb __user *user_iocb, bool compat)
struct iocb __user *user_iocb, struct aio_kiocb *req,
bool compat)
{
struct aio_kiocb *req;
int ret;
/* enforce forwards compatibility on users */
if (unlikely(iocb->aio_reserved2)) {
pr_debug("EINVAL: reserve field set\n");
return -EINVAL;
}
/* prevent overflows */
if (unlikely(
(iocb->aio_buf != (unsigned long)iocb->aio_buf) ||
(iocb->aio_nbytes != (size_t)iocb->aio_nbytes) ||
((ssize_t)iocb->aio_nbytes < 0)
)) {
pr_debug("EINVAL: overflow check\n");
return -EINVAL;
}
req = aio_get_req(ctx);
if (unlikely(!req))
return -EAGAIN;
req->ki_filp = fget(iocb->aio_fildes);
ret = -EBADF;
if (unlikely(!req->ki_filp))
goto out_put_req;
return -EBADF;
if (iocb->aio_flags & IOCB_FLAG_RESFD) {
struct eventfd_ctx *eventfd;
@ -1816,17 +1793,15 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
* event using the eventfd_signal() function.
*/
eventfd = eventfd_ctx_fdget(iocb->aio_resfd);
if (IS_ERR(eventfd)) {
ret = PTR_ERR(eventfd);
goto out_put_req;
}
if (IS_ERR(eventfd))
return PTR_ERR(req->ki_eventfd);
req->ki_eventfd = eventfd;
}
ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
if (unlikely(ret)) {
if (unlikely(put_user(KIOCB_KEY, &user_iocb->aio_key))) {
pr_debug("EFAULT: aio_key\n");
goto out_put_req;
return -EFAULT;
}
req->ki_res.obj = (u64)(unsigned long)user_iocb;
@ -1836,58 +1811,70 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb,
switch (iocb->aio_lio_opcode) {
case IOCB_CMD_PREAD:
ret = aio_read(&req->rw, iocb, false, compat);
break;
return aio_read(&req->rw, iocb, false, compat);
case IOCB_CMD_PWRITE:
ret = aio_write(&req->rw, iocb, false, compat);
break;
return aio_write(&req->rw, iocb, false, compat);
case IOCB_CMD_PREADV:
ret = aio_read(&req->rw, iocb, true, compat);
break;
return aio_read(&req->rw, iocb, true, compat);
case IOCB_CMD_PWRITEV:
ret = aio_write(&req->rw, iocb, true, compat);
break;
return aio_write(&req->rw, iocb, true, compat);
case IOCB_CMD_FSYNC:
ret = aio_fsync(&req->fsync, iocb, false);
break;
return aio_fsync(&req->fsync, iocb, false);
case IOCB_CMD_FDSYNC:
ret = aio_fsync(&req->fsync, iocb, true);
break;
return aio_fsync(&req->fsync, iocb, true);
case IOCB_CMD_POLL:
ret = aio_poll(req, iocb);
break;
return aio_poll(req, iocb);
default:
pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
ret = -EINVAL;
break;
return -EINVAL;
}
/* Done with the synchronous reference */
iocb_put(req);
/*
* If ret is 0, we'd either done aio_complete() ourselves or have
* arranged for that to be done asynchronously. Anything non-zero
* means that we need to destroy req ourselves.
*/
if (!ret)
return 0;
out_put_req:
iocb_destroy(req);
put_reqs_available(ctx, 1);
return ret;
}
static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
bool compat)
{
struct aio_kiocb *req;
struct iocb iocb;
int err;
if (unlikely(copy_from_user(&iocb, user_iocb, sizeof(iocb))))
return -EFAULT;
return __io_submit_one(ctx, &iocb, user_iocb, compat);
/* enforce forwards compatibility on users */
if (unlikely(iocb.aio_reserved2)) {
pr_debug("EINVAL: reserve field set\n");
return -EINVAL;
}
/* prevent overflows */
if (unlikely(
(iocb.aio_buf != (unsigned long)iocb.aio_buf) ||
(iocb.aio_nbytes != (size_t)iocb.aio_nbytes) ||
((ssize_t)iocb.aio_nbytes < 0)
)) {
pr_debug("EINVAL: overflow check\n");
return -EINVAL;
}
req = aio_get_req(ctx);
if (unlikely(!req))
return -EAGAIN;
err = __io_submit_one(ctx, &iocb, user_iocb, req, compat);
/* Done with the synchronous reference */
iocb_put(req);
/*
* If err is 0, we'd either done aio_complete() ourselves or have
* arranged for that to be done asynchronously. Anything non-zero
* means that we need to destroy req ourselves.
*/
if (unlikely(err)) {
iocb_destroy(req);
put_reqs_available(ctx, 1);
}
return err;
}
/* sys_io_submit: