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
13 static atomic_t afs_operation_debug_counter;
14
15 /*
16 * Create an operation against a volume.
17 */
18 struct 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 */
55 static 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
99 static 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
112 static 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 */
138 bool 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 */
160 static 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 */
179 void 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 && op->server)
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 */
230 int 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
273 int 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
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