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

From: Trond Myklebust
Date: Mon Feb 14 2011 - 17:10:10 EST


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).

Cheers
Trond

--
Trond Myklebust
Linux NFS client maintainer

NetApp
Trond.Myklebust@xxxxxxxxxx
www.netapp.com

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