1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Fileserver-directed operation handling.
3 *
4 * Copyright (C) 2020 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/kernel.h>
9#include <linux/slab.h>
10#include <linux/fs.h>
11#include "internal.h"
12
13static atomic_t afs_operation_debug_counter;
14
15/*
16 * Create an operation against a volume.
17 */
18struct afs_operation *afs_alloc_operation(struct key *key, struct afs_volume *volume)
19{
20	struct afs_operation *op;
21
22	_enter("");
23
24	op = kzalloc(sizeof(*op), GFP_KERNEL);
25	if (!op)
26		return ERR_PTR(-ENOMEM);
27
28	if (!key) {
29		key = afs_request_key(volume->cell);
30		if (IS_ERR(key)) {
31			kfree(op);
32			return ERR_CAST(key);
33		}
34	} else {
35		key_get(key);
36	}
37
38	op->key			= key;
39	op->volume		= afs_get_volume(volume, afs_volume_trace_get_new_op);
40	op->net			= volume->cell->net;
41	op->cb_v_break		= atomic_read(&volume->cb_v_break);
42	op->pre_volsync.creation = volume->creation_time;
43	op->pre_volsync.update	= volume->update_time;
44	op->debug_id		= atomic_inc_return(&afs_operation_debug_counter);
45	op->nr_iterations	= -1;
46	afs_op_set_error(op, -EDESTADDRREQ);
47
48	_leave(" = [op=%08x]", op->debug_id);
49	return op;
50}
51
52/*
53 * Lock the vnode(s) being operated upon.
54 */
55static bool afs_get_io_locks(struct afs_operation *op)
56{
57	struct afs_vnode *vnode = op->file[0].vnode;
58	struct afs_vnode *vnode2 = op->file[1].vnode;
59
60	_enter("");
61
62	if (op->flags & AFS_OPERATION_UNINTR) {
63		mutex_lock(&vnode->io_lock);
64		op->flags |= AFS_OPERATION_LOCK_0;
65		_leave(" = t [1]");
66		return true;
67	}
68
69	if (!vnode2 || !op->file[1].need_io_lock || vnode == vnode2)
70		vnode2 = NULL;
71
72	if (vnode2 > vnode)
73		swap(vnode, vnode2);
74
75	if (mutex_lock_interruptible(&vnode->io_lock) < 0) {
76		afs_op_set_error(op, -ERESTARTSYS);
77		op->flags |= AFS_OPERATION_STOP;
78		_leave(" = f [I 0]");
79		return false;
80	}
81	op->flags |= AFS_OPERATION_LOCK_0;
82
83	if (vnode2) {
84		if (mutex_lock_interruptible_nested(&vnode2->io_lock, 1) < 0) {
85			afs_op_set_error(op, -ERESTARTSYS);
86			op->flags |= AFS_OPERATION_STOP;
87			mutex_unlock(&vnode->io_lock);
88			op->flags &= ~AFS_OPERATION_LOCK_0;
89			_leave(" = f [I 1]");
90			return false;
91		}
92		op->flags |= AFS_OPERATION_LOCK_1;
93	}
94
95	_leave(" = t [2]");
96	return true;
97}
98
99static void afs_drop_io_locks(struct afs_operation *op)
100{
101	struct afs_vnode *vnode = op->file[0].vnode;
102	struct afs_vnode *vnode2 = op->file[1].vnode;
103
104	_enter("");
105
106	if (op->flags & AFS_OPERATION_LOCK_1)
107		mutex_unlock(&vnode2->io_lock);
108	if (op->flags & AFS_OPERATION_LOCK_0)
109		mutex_unlock(&vnode->io_lock);
110}
111
112static void afs_prepare_vnode(struct afs_operation *op, struct afs_vnode_param *vp,
113			      unsigned int index)
114{
115	struct afs_vnode *vnode = vp->vnode;
116
117	if (vnode) {
118		vp->fid			= vnode->fid;
119		vp->dv_before		= vnode->status.data_version;
120		vp->cb_break_before	= afs_calc_vnode_cb_break(vnode);
121		if (vnode->lock_state != AFS_VNODE_LOCK_NONE)
122			op->flags	|= AFS_OPERATION_CUR_ONLY;
123		if (vp->modification)
124			set_bit(AFS_VNODE_MODIFYING, &vnode->flags);
125	}
126
127	if (vp->fid.vnode)
128		_debug("PREP[%u] {%llx:%llu.%u}",
129		       index, vp->fid.vid, vp->fid.vnode, vp->fid.unique);
130}
131
132/*
133 * Begin an operation on the fileserver.
134 *
135 * Fileserver operations are serialised on the server by vnode, so we serialise
136 * them here also using the io_lock.
137 */
138bool afs_begin_vnode_operation(struct afs_operation *op)
139{
140	struct afs_vnode *vnode = op->file[0].vnode;
141
142	ASSERT(vnode);
143
144	_enter("");
145
146	if (op->file[0].need_io_lock)
147		if (!afs_get_io_locks(op))
148			return false;
149
150	afs_prepare_vnode(op, &op->file[0], 0);
151	afs_prepare_vnode(op, &op->file[1], 1);
152	op->cb_v_break = atomic_read(&op->volume->cb_v_break);
153	_leave(" = true");
154	return true;
155}
156
157/*
158 * Tidy up a filesystem cursor and unlock the vnode.
159 */
160static void afs_end_vnode_operation(struct afs_operation *op)
161{
162	_enter("");
163
164	switch (afs_op_error(op)) {
165	case -EDESTADDRREQ:
166	case -EADDRNOTAVAIL:
167	case -ENETUNREACH:
168	case -EHOSTUNREACH:
169		afs_dump_edestaddrreq(op);
170		break;
171	}
172
173	afs_drop_io_locks(op);
174}
175
176/*
177 * Wait for an in-progress operation to complete.
178 */
179void afs_wait_for_operation(struct afs_operation *op)
180{
181	_enter("");
182
183	while (afs_select_fileserver(op)) {
184		op->call_responded = false;
185		op->call_error = 0;
186		op->call_abort_code = 0;
187		if (test_bit(AFS_SERVER_FL_IS_YFS, &op->server->flags) &&
188		    op->ops->issue_yfs_rpc)
189			op->ops->issue_yfs_rpc(op);
190		else if (op->ops->issue_afs_rpc)
191			op->ops->issue_afs_rpc(op);
192		else
193			op->call_error = -ENOTSUPP;
194
195		if (op->call) {
196			afs_wait_for_call_to_complete(op->call);
197			op->call_abort_code = op->call->abort_code;
198			op->call_error = op->call->error;
199			op->call_responded = op->call->responded;
200			afs_put_call(op->call);
201		}
202	}
203
204	if (op->call_responded)
205		set_bit(AFS_SERVER_FL_RESPONDING, &op->server->flags);
206
207	if (!afs_op_error(op)) {
208		_debug("success");
209		op->ops->success(op);
210	} else if (op->cumul_error.aborted) {
211		if (op->ops->aborted)
212			op->ops->aborted(op);
213	} else {
214		if (op->ops->failed)
215			op->ops->failed(op);
216	}
217
218	afs_end_vnode_operation(op);
219
220	if (!afs_op_error(op) && op->ops->edit_dir) {
221		_debug("edit_dir");
222		op->ops->edit_dir(op);
223	}
224	_leave("");
225}
226
227/*
228 * Dispose of an operation.
229 */
230int afs_put_operation(struct afs_operation *op)
231{
232	struct afs_addr_list *alist;
233	int i, ret = afs_op_error(op);
234
235	_enter("op=%08x,%d", op->debug_id, ret);
236
237	if (op->ops && op->ops->put)
238		op->ops->put(op);
239	if (op->file[0].modification)
240		clear_bit(AFS_VNODE_MODIFYING, &op->file[0].vnode->flags);
241	if (op->file[1].modification && op->file[1].vnode != op->file[0].vnode)
242		clear_bit(AFS_VNODE_MODIFYING, &op->file[1].vnode->flags);
243	if (op->file[0].put_vnode)
244		iput(&op->file[0].vnode->netfs.inode);
245	if (op->file[1].put_vnode)
246		iput(&op->file[1].vnode->netfs.inode);
247
248	if (op->more_files) {
249		for (i = 0; i < op->nr_files - 2; i++)
250			if (op->more_files[i].put_vnode)
251				iput(&op->more_files[i].vnode->netfs.inode);
252		kfree(op->more_files);
253	}
254
255	if (op->estate) {
256		alist = op->estate->addresses;
257		if (alist) {
258			if (op->call_responded &&
259			    op->addr_index != alist->preferred &&
260			    test_bit(alist->preferred, &op->addr_tried))
261				WRITE_ONCE(alist->preferred, op->addr_index);
262		}
263	}
264
265	afs_clear_server_states(op);
266	afs_put_serverlist(op->net, op->server_list);
267	afs_put_volume(op->volume, afs_volume_trace_put_put_op);
268	key_put(op->key);
269	kfree(op);
270	return ret;
271}
272
273int afs_do_sync_operation(struct afs_operation *op)
274{
275	afs_begin_vnode_operation(op);
276	afs_wait_for_operation(op);
277	return afs_put_operation(op);
278}
279