2017-05-24 16:41:43

by Goldwyn Rodrigues

Subject: [PATCH 03/10] fs: Use RWF_* flags for AIO operations

From: Goldwyn Rodrigues <rgoldwyn-IBi9RG/[email protected]>

aio_rw_flags is introduced in struct iocb (using aio_reserved1) which will
carry the RWF_* flags. We cannot use aio_flags because they are not
checked for validity which may break existing applications.

Note, the only place RWF_HIPRI comes in effect is dio_await_one().
All the rest of the locations, aio code return -EIOCBQUEUED before the
checks for RWF_HIPRI.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn-IBi9RG/[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
---
fs/aio.c | 8 +++++++-
include/uapi/linux/aio_abi.h | 2 +-
2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/aio.c b/fs/aio.c
index f52d925ee259..020fa0045e3c 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1541,7 +1541,7 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
ssize_t ret;

/* enforce forwards compatibility on users */
- if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2)) {
+ if (unlikely(iocb->aio_reserved2)) {
pr_debug("EINVAL: reserve field set\n");
return -EINVAL;
}
@@ -1586,6 +1586,12 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
req->common.ki_flags |= IOCB_EVENTFD;
}

+ ret = kiocb_set_rw_flags(&req->common, iocb->aio_rw_flags);
+ if (unlikely(ret)) {
+ pr_debug("EINVAL: aio_rw_flags\n");
+ goto out_put_req;
+ }
+
ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
if (unlikely(ret)) {
pr_debug("EFAULT: aio_key\n");
diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
index bb2554f7fbd1..a2d4a8ac94ca 100644
--- a/include/uapi/linux/aio_abi.h
+++ b/include/uapi/linux/aio_abi.h
@@ -79,7 +79,7 @@ struct io_event {
struct iocb {
/* these are internal to the kernel/libc. */
__u64 aio_data; /* data to be returned in event's data */
- __u32 PADDED(aio_key, aio_reserved1);
+ __u32 PADDED(aio_key, aio_rw_flags);
/* the kernel sets aio_key to the req # */

/* common fields */
--
2.12.0

2017-05-25 08:27:45

by Jan Kara

Subject: Re: [PATCH 03/10] fs: Use RWF_* flags for AIO operations

On Wed 24-05-17 11:41:43, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <[email protected]>
>
> aio_rw_flags is introduced in struct iocb (using aio_reserved1) which will
> carry the RWF_* flags. We cannot use aio_flags because they are not
> checked for validity which may break existing applications.
>
> Note, the only place RWF_HIPRI comes in effect is dio_await_one().
> All the rest of the locations, aio code return -EIOCBQUEUED before the
> checks for RWF_HIPRI.
>
> Signed-off-by: Goldwyn Rodrigues <[email protected]>
> Reviewed-by: Christoph Hellwig <[email protected]>

Looks good. You can add:

Reviewed-by: Jan Kara <[email protected]>

Honza

> ---
> fs/aio.c | 8 +++++++-
> include/uapi/linux/aio_abi.h | 2 +-
> 2 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/fs/aio.c b/fs/aio.c
> index f52d925ee259..020fa0045e3c 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -1541,7 +1541,7 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
> ssize_t ret;
>
> /* enforce forwards compatibility on users */
> - if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2)) {
> + if (unlikely(iocb->aio_reserved2)) {
> pr_debug("EINVAL: reserve field set\n");
> return -EINVAL;
> }
> @@ -1586,6 +1586,12 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
> req->common.ki_flags |= IOCB_EVENTFD;
> }
>
> + ret = kiocb_set_rw_flags(&req->common, iocb->aio_rw_flags);
> + if (unlikely(ret)) {
> + pr_debug("EINVAL: aio_rw_flags\n");
> + goto out_put_req;
> + }
> +
> ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
> if (unlikely(ret)) {
> pr_debug("EFAULT: aio_key\n");
> diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
> index bb2554f7fbd1..a2d4a8ac94ca 100644
> --- a/include/uapi/linux/aio_abi.h
> +++ b/include/uapi/linux/aio_abi.h
> @@ -79,7 +79,7 @@ struct io_event {
> struct iocb {
> /* these are internal to the kernel/libc. */
> __u64 aio_data; /* data to be returned in event's data */
> - __u32 PADDED(aio_key, aio_reserved1);
> + __u32 PADDED(aio_key, aio_rw_flags);
> /* the kernel sets aio_key to the req # */
>
> /* common fields */
> --
> 2.12.0
>
--
Jan Kara <[email protected]>
SUSE Labs, CR