afs: Get YFS ACLs and information through xattrs

The YFS/AuriStor variant of AFS provides more capable ACLs and provides
per-volume ACLs and per-file ACLs as well as per-directory ACLs.  It also
provides some extra information that can be retrieved through four ACLs:

 (1) afs.yfs.acl

     The YFS file ACL (not the same format as afs.acl).

 (2) afs.yfs.vol_acl

     The YFS volume ACL.

 (3) afs.yfs.acl_inherited

     "1" if a file's ACL is inherited from its parent directory, "0"
     otherwise.

 (4) afs.yfs.acl_num_cleaned

     The number of of ACEs removed from the ACL by the server because the
     PT entries were removed from the PTS database (ie. the subject is no
     longer known).

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 188 insertions, 0 deletions

diff --git a/fs/afs/yfsclient.c b/fs/afs/yfsclient.c
index 055840aa07f6..13eafa764d71 100644
--- a/fs/afs/yfsclient.c
+++ b/fs/afs/yfsclient.c
@@ -2204,3 +2204,191 @@ int yfs_fs_inline_bulk_status(struct afs_fs_cursor *fc,
 	afs_make_call(&fc->ac, call, GFP_NOFS);
 	return afs_wait_for_call_to_complete(call, &fc->ac);
 }
+
+/*
+ * Deliver reply data to an YFS.FetchOpaqueACL.
+ */
+static int yfs_deliver_fs_fetch_opaque_acl(struct afs_call *call)
+{
+	struct afs_volsync *volsync = call->reply[2];
+	struct afs_vnode *vnode = call->reply[1];
+	struct yfs_acl *yacl =  call->reply[0];
+	struct afs_acl *acl;
+	const __be32 *bp;
+	unsigned int size;
+	int ret;
+
+	_enter("{%u}", call->unmarshall);
+
+	switch (call->unmarshall) {
+	case 0:
+		afs_extract_to_tmp(call);
+		call->unmarshall++;
+
+		/* Extract the file ACL length */
+	case 1:
+		ret = afs_extract_data(call, true);
+		if (ret < 0)
+			return ret;
+
+		size = call->count2 = ntohl(call->tmp);
+		size = round_up(size, 4);
+
+		if (yacl->flags & YFS_ACL_WANT_ACL) {
+			acl = kmalloc(struct_size(acl, data, size), GFP_KERNEL);
+			if (!acl)
+				return -ENOMEM;
+			yacl->acl = acl;
+			acl->size = call->count2;
+			afs_extract_begin(call, acl->data, size);
+		} else {
+			iov_iter_discard(&call->iter, READ, size);
+		}
+		call->unmarshall++;
+
+		/* Extract the file ACL */
+	case 2:
+		ret = afs_extract_data(call, true);
+		if (ret < 0)
+			return ret;
+
+		afs_extract_to_tmp(call);
+		call->unmarshall++;
+
+		/* Extract the volume ACL length */
+	case 3:
+		ret = afs_extract_data(call, true);
+		if (ret < 0)
+			return ret;
+
+		size = call->count2 = ntohl(call->tmp);
+		size = round_up(size, 4);
+
+		if (yacl->flags & YFS_ACL_WANT_VOL_ACL) {
+			acl = kmalloc(struct_size(acl, data, size), GFP_KERNEL);
+			if (!acl)
+				return -ENOMEM;
+			yacl->vol_acl = acl;
+			acl->size = call->count2;
+			afs_extract_begin(call, acl->data, size);
+		} else {
+			iov_iter_discard(&call->iter, READ, size);
+		}
+		call->unmarshall++;
+
+		/* Extract the volume ACL */
+	case 4:
+		ret = afs_extract_data(call, true);
+		if (ret < 0)
+			return ret;
+
+		afs_extract_to_buf(call,
+				   sizeof(__be32) * 2 +
+				   sizeof(struct yfs_xdr_YFSFetchStatus) +
+				   sizeof(struct yfs_xdr_YFSVolSync));
+		call->unmarshall++;
+
+		/* extract the metadata */
+	case 5:
+		ret = afs_extract_data(call, false);
+		if (ret < 0)
+			return ret;
+
+		bp = call->buffer;
+		yacl->inherit_flag = ntohl(*bp++);
+		yacl->num_cleaned = ntohl(*bp++);
+		ret = yfs_decode_status(call, &bp, &vnode->status, vnode,
+					&call->expected_version, NULL);
+		if (ret < 0)
+			return ret;
+		xdr_decode_YFSVolSync(&bp, volsync);
+
+		call->unmarshall++;
+
+	case 6:
+		break;
+	}
+
+	_leave(" = 0 [done]");
+	return 0;
+}
+
+void yfs_free_opaque_acl(struct yfs_acl *yacl)
+{
+	if (yacl) {
+		kfree(yacl->acl);
+		kfree(yacl->vol_acl);
+		kfree(yacl);
+	}
+}
+
+static void yfs_destroy_fs_fetch_opaque_acl(struct afs_call *call)
+{
+	yfs_free_opaque_acl(call->reply[0]);
+	afs_flat_call_destructor(call);
+}
+
+/*
+ * YFS.FetchOpaqueACL operation type
+ */
+static const struct afs_call_type yfs_RXYFSFetchOpaqueACL = {
+	.name		= "YFS.FetchOpaqueACL",
+	.op		= yfs_FS_FetchOpaqueACL,
+	.deliver	= yfs_deliver_fs_fetch_opaque_acl,
+	.destructor	= yfs_destroy_fs_fetch_opaque_acl,
+};
+
+/*
+ * Fetch the YFS advanced ACLs for a file.
+ */
+struct yfs_acl *yfs_fs_fetch_opaque_acl(struct afs_fs_cursor *fc,
+					unsigned int flags)
+{
+	struct afs_vnode *vnode = fc->vnode;
+	struct afs_call *call;
+	struct yfs_acl *yacl;
+	struct afs_net *net = afs_v2net(vnode);
+	__be32 *bp;
+
+	_enter(",%x,{%llx:%llu},,",
+	       key_serial(fc->key), vnode->fid.vid, vnode->fid.vnode);
+
+	call = afs_alloc_flat_call(net, &yfs_RXYFSFetchOpaqueACL,
+				   sizeof(__be32) * 2 +
+				   sizeof(struct yfs_xdr_YFSFid),
+				   sizeof(__be32) * 2 +
+				   sizeof(struct yfs_xdr_YFSFetchStatus) +
+				   sizeof(struct yfs_xdr_YFSVolSync));
+	if (!call)
+		goto nomem;
+
+	yacl = kzalloc(sizeof(struct yfs_acl), GFP_KERNEL);
+	if (!yacl)
+		goto nomem_call;
+
+	yacl->flags = flags;
+	call->key = fc->key;
+	call->reply[0] = yacl;
+	call->reply[1] = vnode;
+	call->reply[2] = NULL; /* volsync */
+	call->ret_reply0 = true;
+
+	/* marshall the parameters */
+	bp = call->request;
+	bp = xdr_encode_u32(bp, YFSFETCHOPAQUEACL);
+	bp = xdr_encode_u32(bp, 0); /* RPC flags */
+	bp = xdr_encode_YFSFid(bp, &vnode->fid);
+	yfs_check_req(call, bp);
+
+	call->cb_break = fc->cb_break;
+	afs_use_fs_server(call, fc->cbi);
+	trace_afs_make_fs_call(call, &vnode->fid);
+	afs_make_call(&fc->ac, call, GFP_KERNEL);
+	return (struct yfs_acl *)afs_wait_for_call_to_complete(call, &fc->ac);
+
+nomem_call:
+	afs_put_call(call);
+nomem:
+	fc->ac.error = -ENOMEM;
+	return ERR_PTR(-ENOMEM);
+}