Re: [PATCH v2] ceph: Fix file open flags on ppc64

[Yan, Zheng]

> On 28 Apr 2017, at 00:34, Alexander Graf <agraf@xxxxxxx> wrote:
> 
> The file open flags (O_foo) are platform specific and should never go
> out to an interface that is not local to the system.
> 
> Unfortunately these flags have leaked out onto the wire in the cephfs
> implementation. That lead to bogus flags getting transmitted on ppc64.
> 
> This patch converts the kernel view of flags to the ceph view of file
> open flags.
> 
> Fixes: 124e68e74 ("ceph: file operations")
> Signed-off-by: Alexander Graf <agraf@xxxxxxx>
> 
> â

I removed the "unused open flagsâ dout and applied the patch. Thank you for tracking down and fixing the bug.

Regards
Yan, Zheng

> 
> v1 -> v2:
> 
>  - Only convert flags mds knows about
>  - Fix le conversion
> ---
> fs/ceph/file.c               | 35 ++++++++++++++++++++++++++++++++++-
> include/linux/ceph/ceph_fs.h | 12 ++++++++++++
> 2 files changed, 46 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 26cc954..9cac018 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -103,6 +103,39 @@ static size_t dio_get_pagev_size(const struct iov_iter *it)
> 	return ERR_PTR(ret);
> }
> 
> +static __le32 ceph_flags_sys2wire(u32 flags)
> +{
> +	u32 wire_flags = 0;
> +
> +	switch (flags & O_ACCMODE) {
> +	case O_RDONLY:
> +		wire_flags |= CEPH_O_RDONLY;
> +		break;
> +	case O_WRONLY:
> +		wire_flags |= CEPH_O_WRONLY;
> +		break;
> +	case O_RDWR:
> +		wire_flags |= CEPH_O_RDWR;
> +		break;
> +	}
> +	flags &= ~O_ACCMODE;
> +
> +#define ceph_sys2wire(a) if (flags & a) { wire_flags |= CEPH_##a; flags &= ~a; }
> +
> +	ceph_sys2wire(O_CREAT);
> +	ceph_sys2wire(O_EXCL);
> +	ceph_sys2wire(O_TRUNC);
> +	ceph_sys2wire(O_DIRECTORY);
> +	ceph_sys2wire(O_NOFOLLOW);
> +
> +#undef ceph_sys2wire
> +
> +	if (flags)
> +		dout("Unused open flags: %x", flags);
> +
> +	return cpu_to_le32(wire_flags);
> +}
> +
> /*
>  * Prepare an open request.  Preallocate ceph_cap to avoid an
>  * inopportune ENOMEM later.
> @@ -123,7 +156,7 @@ static size_t dio_get_pagev_size(const struct iov_iter *it)
> 	if (IS_ERR(req))
> 		goto out;
> 	req->r_fmode = ceph_flags_to_mode(flags);
> -	req->r_args.open.flags = cpu_to_le32(flags);
> +	req->r_args.open.flags = ceph_flags_sys2wire(flags);
> 	req->r_args.open.mode = cpu_to_le32(create_mode);
> out:
> 	return req;
> diff --git a/include/linux/ceph/ceph_fs.h b/include/linux/ceph/ceph_fs.h
> index f4b2ee1..9581c70 100644
> --- a/include/linux/ceph/ceph_fs.h
> +++ b/include/linux/ceph/ceph_fs.h
> @@ -366,6 +366,18 @@ enum {
> #define CEPH_READDIR_FRAG_COMPLETE	(1<<8)
> #define CEPH_READDIR_HASH_ORDER		(1<<9)
> 
> +/*
> + * open request flags
> + */
> +#define CEPH_O_RDONLY		00000000
> +#define CEPH_O_WRONLY		00000001
> +#define CEPH_O_RDWR		00000002
> +#define CEPH_O_CREAT		00000100
> +#define CEPH_O_EXCL		00000200
> +#define CEPH_O_TRUNC		00001000
> +#define CEPH_O_DIRECTORY	00200000
> +#define CEPH_O_NOFOLLOW		00400000
> +
> union ceph_mds_request_args {
> 	struct {
> 		__le32 mask;                 /* CEPH_CAP_* */
> -- 
> 1.8.5.6
>