Re: [PATCH 17/21] ceph: nfs re-export support

From: Sage Weil
Date: Sat Jun 20 2009 - 16:39:53 EST


On Sat, 20 Jun 2009, Stefan Richter wrote:
> Sage Weil wrote:
> > +++ b/fs/staging/ceph/export.c
> ...
> > +static struct dentry *ceph_fh_to_parent(struct super_block *sb, struct fid
> > *fid,
> > + int fh_len, int fh_type)
> > +{
> > + u32 *fh = fid->raw;
> > + u64 ino = *(u64 *)fh;
> > + u32 hash = fh[2];
> > +
> > + derr(10, "fh_to_parent %llx.%x\n", ino, hash);
> > +
> > + if (fh_len < 6)
> > + return ERR_PTR(-ESTALE);
> > +
> > + return __fh_to_dentry(sb, (struct ceph_export_item *)fh + 1,
> > + fh_len/IPSZ - 1);
> > +}
>
> fid->raw could be 32-bit aligned, couldn't it?
>
> #include <asm/unaligned.h>
>
> u64 ino = get_unaligned((u64 *)fh);

Hmm, yeah. I've done the same thing in a bunch of other places, too, the
big offender being decode.h, where e.g.

v = le64_to_cpu(*(__le64 *)*(p)); \
*(p) += sizeof(u64); \

should be

v = le64_to_cpu(get_unaligned((__le64 *)*(p))); \
*(p) += sizeof(u64); \

I'll do a full audit to clean these up.

> derr(10, "fh_to_parent %llx.%x\n",
> (unsigned long long)ino, hash);

I've been secretly hoping someone will add printk format specifiers for
fixed size u32 and u64 so I can avoid sprinkling hundreds of (unsigned
long long)'s throughout. Is an explicit cast really the cleanest way to
fix this?

Thanks!
sage
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