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

From: Sage Weil
Date: Wed May 15 2013 - 20:10:38 EST


On Wed, 15 May 2013, Alex Elder wrote:
> 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).

The server-side endianness conversions are all done through the magic of
C++ for the __le* types. Should be good!

sge


>
> 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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