> On 21 Apr 2017, at 21:59, Alexander Graf <agraf@xxxxxxx> wrote:
>
>
>
> On 21.04.17 04:22, Yan, Zheng wrote:
>>
>>> On 20 Apr 2017, at 20:40, 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. On x86 systems, the new function should get optimized out
>>> by smart compilers. On systems where the flags differ, it should adapt
>>> them accordingly.
>>>
>>> Fixes: 124e68e74 ("ceph: file operations")
>>> Signed-off-by: Alexander Graf <agraf@xxxxxxx>
>>> ---
>>> fs/ceph/file.c | 45 +++++++++++++++++++++++++++++++++++++++++++-
>>> include/linux/ceph/ceph_fs.h | 24 +++++++++++++++++++++++
>>> 2 files changed, 68 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
>>> index 26cc954..0ed6392 100644
>>> --- a/fs/ceph/file.c
>>> +++ b/fs/ceph/file.c
>>> @@ -103,6 +103,49 @@ static size_t dio_get_pagev_size(const struct iov_iter *it)
>>> return ERR_PTR(ret);
>>> }
>>>
>>> +static u32 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_NOCTTY);
>>> + ceph_sys2wire(O_TRUNC);
>>> + ceph_sys2wire(O_APPEND);
>>> + ceph_sys2wire(O_NONBLOCK);
>>> + ceph_sys2wire(O_DSYNC);
>>> + ceph_sys2wire(FASYNC);
>>> + ceph_sys2wire(O_DIRECT);
>>> + ceph_sys2wire(O_LARGEFILE);
>>> + ceph_sys2wire(O_DIRECTORY);
>>> + ceph_sys2wire(O_NOFOLLOW);
>>> + ceph_sys2wire(O_NOATIME);
>>> + ceph_sys2wire(O_CLOEXEC);
>>> + ceph_sys2wire(__O_SYNC);
>>> + ceph_sys2wire(O_PATH);
>>> + ceph_sys2wire(__O_TMPFILE);
>>> +
>>> +#undef ceph_sys2wire
>>> +
>>> + WARN_ONCE(flags, "Found unknown open flags: %x", flags);
>>> +
>>> + return wire_flags;
>>> +}
>>> +
>>> /*
>>> * Prepare an open request. Preallocate ceph_cap to avoid an
>>> * inopportune ENOMEM later.
>>> @@ -123,7 +166,7 @@ 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(cpu_to_le32(flags));
>>
>> cpu_to_le32(ceph_flags_sys2wire(flags)) ?
>
> Jeff also pointed to it. Definitely, yes. My thinko.
>
>>
>>> 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..d254b48 100644
>>> --- a/include/linux/ceph/ceph_fs.h
>>> +++ b/include/linux/ceph/ceph_fs.h
>>> @@ -366,6 +366,30 @@ 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_NOCTTY 00000400
>>> +#define CEPH_O_TRUNC 00001000
>>> +#define CEPH_O_APPEND 00002000
>>> +#define CEPH_O_NONBLOCK 00004000
>>> +#define CEPH_O_DSYNC 00010000
>>> +#define CEPH_FASYNC 00020000
>>> +#define CEPH_O_DIRECT 00040000
>>> +#define CEPH_O_LARGEFILE 00100000
>>> +#define CEPH_O_DIRECTORY 00200000
>>> +#define CEPH_O_NOFOLLOW 00400000
>>> +#define CEPH_O_NOATIME 01000000
>>> +#define CEPH_O_CLOEXEC 02000000
>>> +#define CEPH___O_SYNC 04000000
>>> +#define CEPH_O_PATH 010000000
>>> +#define CEPH___O_TMPFILE 020000000
>>> +
>>
>> RDONLY, WRONLY, RDWR, CREAT, EXCL, TRUNC, DIRECTORY, NOFOLLOW are used by mds, no need to define the rest.
>
> So currently the function checks for any bits it doesn't know about. Do we want to drop that check then?
yes. I think it’s better to only encode flags that mds understands to wire.
Regards
Yan, Zheng
>
>
> Alex
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