NFSv4: include bitmap in nfsv4 get acl data
The NFSv4 bitmap size is unbounded: a server can return an arbitrary
sized bitmap in an FATTR4_WORD0_ACL request. Replace using the
nfs4_fattr_bitmap_maxsz as a guess to the maximum bitmask returned by a server
with the inclusion of the bitmap (xdr length plus bitmasks) and the acl data
xdr length to the (cached) acl page data.
This is a general solution to commit e5012d1f "NFSv4.1: update
nfs4_fattr_bitmap_maxsz" and fixes hitting a BUG_ON in xdr_shrink_bufhead
when getting ACLs.
Fix a bug in decode_getacl that returned -EINVAL on ACLs > page when getxattr
was called with a NULL buffer, preventing ACL > PAGE_SIZE from being retrieved.
Cc: stable@kernel.org
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index e6161b2..dcaf693 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -2517,11 +2517,13 @@
encode_compound_hdr(xdr, req, &hdr);
encode_sequence(xdr, &args->seq_args, &hdr);
encode_putfh(xdr, args->fh, &hdr);
- replen = hdr.replen + op_decode_hdr_maxsz + nfs4_fattr_bitmap_maxsz + 1;
+ replen = hdr.replen + op_decode_hdr_maxsz + 1;
encode_getattr_two(xdr, FATTR4_WORD0_ACL, 0, &hdr);
xdr_inline_pages(&req->rq_rcv_buf, replen << 2,
args->acl_pages, args->acl_pgbase, args->acl_len);
+ xdr_set_scratch_buffer(xdr, page_address(args->acl_scratch), PAGE_SIZE);
+
encode_nops(&hdr);
}
@@ -4957,17 +4959,18 @@
}
static int decode_getacl(struct xdr_stream *xdr, struct rpc_rqst *req,
- size_t *acl_len)
+ struct nfs_getaclres *res)
{
- __be32 *savep;
+ __be32 *savep, *bm_p;
uint32_t attrlen,
bitmap[3] = {0};
struct kvec *iov = req->rq_rcv_buf.head;
int status;
- *acl_len = 0;
+ res->acl_len = 0;
if ((status = decode_op_hdr(xdr, OP_GETATTR)) != 0)
goto out;
+ bm_p = xdr->p;
if ((status = decode_attr_bitmap(xdr, bitmap)) != 0)
goto out;
if ((status = decode_attr_length(xdr, &attrlen, &savep)) != 0)
@@ -4979,18 +4982,30 @@
size_t hdrlen;
u32 recvd;
+ /* The bitmap (xdr len + bitmaps) and the attr xdr len words
+ * are stored with the acl data to handle the problem of
+ * variable length bitmaps.*/
+ xdr->p = bm_p;
+ res->acl_data_offset = be32_to_cpup(bm_p) + 2;
+ res->acl_data_offset <<= 2;
+
/* We ignore &savep and don't do consistency checks on
* the attr length. Let userspace figure it out.... */
hdrlen = (u8 *)xdr->p - (u8 *)iov->iov_base;
+ attrlen += res->acl_data_offset;
recvd = req->rq_rcv_buf.len - hdrlen;
if (attrlen > recvd) {
- dprintk("NFS: server cheating in getattr"
- " acl reply: attrlen %u > recvd %u\n",
+ if (res->acl_flags & NFS4_ACL_LEN_REQUEST) {
+ /* getxattr interface called with a NULL buf */
+ res->acl_len = attrlen;
+ goto out;
+ }
+ dprintk("NFS: acl reply: attrlen %u > recvd %u\n",
attrlen, recvd);
return -EINVAL;
}
xdr_read_pages(xdr, attrlen);
- *acl_len = attrlen;
+ res->acl_len = attrlen;
} else
status = -EOPNOTSUPP;
@@ -6028,7 +6043,7 @@
status = decode_putfh(xdr);
if (status)
goto out;
- status = decode_getacl(xdr, rqstp, &res->acl_len);
+ status = decode_getacl(xdr, rqstp, res);
out:
return status;