Re: [PATCH v2 2/3] ceph: add missing cpu_to_le32() calls when encodinga reconnect capability

From: Alex Elder
Date: Wed May 15 2013 - 12:43:53 EST


On 05/15/2013 11:38 AM, Jim Schutt wrote:
> In his review, Alex Elder mentioned that he hadn't checked that num_fcntl_locks
> and num_flock_locks were properly decoded on the server side, from a le32
> over-the-wire type to a cpu type. I checked, and AFAICS it is done; those
> interested can consult Locker::_do_cap_update() in src/mds/Locker.cc and
> src/include/encoding.h in the Ceph server code (git://github.com/ceph/ceph).
>
> I also checked the server side for flock_len decoding, and I believe that
> also happens correctly, by virtue of having been declared __le32 in
> struct ceph_mds_cap_reconnect, in src/include/ceph_fs.h.
>
> Signed-off-by: Jim Schutt <jaschut@xxxxxxxxxx>

Looks good, but I'd like to get someone else to confirm
the other end is doing it right (i.e., expecting little
endian values).

Reviewed-by: Alex Elder <elder@xxxxxxxxxxx>

> ---
> fs/ceph/locks.c | 7 +++++--
> fs/ceph/mds_client.c | 2 +-
> 2 files changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/fs/ceph/locks.c b/fs/ceph/locks.c
> index ffc86cb..4518313 100644
> --- a/fs/ceph/locks.c
> +++ b/fs/ceph/locks.c
> @@ -206,10 +206,12 @@ int ceph_encode_locks(struct inode *inode, struct ceph_pagelist *pagelist,
> int err = 0;
> int seen_fcntl = 0;
> int seen_flock = 0;
> + __le32 nlocks;
>
> dout("encoding %d flock and %d fcntl locks", num_flock_locks,
> num_fcntl_locks);
> - err = ceph_pagelist_append(pagelist, &num_fcntl_locks, sizeof(u32));
> + nlocks = cpu_to_le32(num_fcntl_locks);
> + err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
> if (err)
> goto fail;
> for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
> @@ -229,7 +231,8 @@ int ceph_encode_locks(struct inode *inode, struct ceph_pagelist *pagelist,
> goto fail;
> }
>
> - err = ceph_pagelist_append(pagelist, &num_flock_locks, sizeof(u32));
> + nlocks = cpu_to_le32(num_flock_locks);
> + err = ceph_pagelist_append(pagelist, &nlocks, sizeof(nlocks));
> if (err)
> goto fail;
> for (lock = inode->i_flock; lock != NULL; lock = lock->fl_next) {
> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
> index 4f22671..d9ca152 100644
> --- a/fs/ceph/mds_client.c
> +++ b/fs/ceph/mds_client.c
> @@ -2485,7 +2485,7 @@ static int encode_caps_cb(struct inode *inode, struct ceph_cap *cap,
> lock_flocks();
> ceph_count_locks(inode, &num_fcntl_locks,
> &num_flock_locks);
> - rec.v2.flock_len = (2*sizeof(u32) +
> + rec.v2.flock_len = cpu_to_le32(2*sizeof(u32) +
> (num_fcntl_locks+num_flock_locks) *
> sizeof(struct ceph_filelock));
> unlock_flocks();
>

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