Re: [PATCH] NFS: Zap entire 'struct inode' innfs_zap_caches_locked().

From: Jesper Juhl
Date: Mon Feb 14 2011 - 17:13:19 EST


On Mon, 14 Feb 2011, Trond Myklebust wrote:

> On Mon, 2011-02-14 at 22:56 +0100, Jesper Juhl wrote:
> > nfs_zap_caches_locked() attempts to zero all of the 'struct inode' that's
> > passed in via the pointer variable 'inode'. Unfortunately it only manages
> > to zero the size of a 'pointer to struct inode'. Fix that.
> >
> > Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
> > ---
> > inode.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > compile tested only
> >
> > diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
> > index 1cc600e..6c4236e 100644
> > --- a/fs/nfs/inode.c
> > +++ b/fs/nfs/inode.c
> > @@ -145,7 +145,7 @@ static void nfs_zap_caches_locked(struct inode *inode)
> > nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
> > nfsi->attrtimeo_timestamp = jiffies;
> >
> > - memset(NFS_COOKIEVERF(inode), 0, sizeof(NFS_COOKIEVERF(inode)));
> > + memset(NFS_COOKIEVERF(inode), 0, sizeof(*NFS_COOKIEVERF(inode)));
> > if (S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))
> > nfsi->cache_validity |= NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA|NFS_INO_INVALID_ACCESS|NFS_INO_INVALID_ACL|NFS_INO_REVAL_PAGECACHE;
> > else
>
> That's incorrect.
>
> NFS_COOKIEVERF(inode) expands to NFS_I(inode)->cookieverf, and since
> cookieverf is declared inside the struct nfs_inode as
>
> u32 cookieverf[2];
>
> the sizeof(NFS_I(inode)->cookieverf) should expand to the size of the
> cookieverf array (i.e. 8 bytes).
>
Ouch, I completely misread/misunderstood that. Thanks for the
clarification and please ignore the patch...

--
Jesper Juhl <jj@xxxxxxxxxxxxx> http://www.chaosbits.net/
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