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 */
afs_alloc_operation(struct key * key,struct afs_volume * volume)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 = volume->cb_v_break;
42 op->debug_id = atomic_inc_return(&afs_operation_debug_counter);
43 op->error = -EDESTADDRREQ;
44 op->ac.error = SHRT_MAX;
45
46 _leave(" = [op=%08x]", op->debug_id);
47 return op;
48 }
49
50 /*
51 * Lock the vnode(s) being operated upon.
52 */
afs_get_io_locks(struct afs_operation * op)53 static bool afs_get_io_locks(struct afs_operation *op)
54 {
55 struct afs_vnode *vnode = op->file[0].vnode;
56 struct afs_vnode *vnode2 = op->file[1].vnode;
57
58 _enter("");
59
60 if (op->flags & AFS_OPERATION_UNINTR) {
61 mutex_lock(&vnode->io_lock);
62 op->flags |= AFS_OPERATION_LOCK_0;
63 _leave(" = t [1]");
64 return true;
65 }
66
67 if (!vnode2 || !op->file[1].need_io_lock || vnode == vnode2)
68 vnode2 = NULL;
69
70 if (vnode2 > vnode)
71 swap(vnode, vnode2);
72
73 if (mutex_lock_interruptible(&vnode->io_lock) < 0) {
74 op->error = -ERESTARTSYS;
75 op->flags |= AFS_OPERATION_STOP;
76 _leave(" = f [I 0]");
77 return false;
78 }
79 op->flags |= AFS_OPERATION_LOCK_0;
80
81 if (vnode2) {
82 if (mutex_lock_interruptible_nested(&vnode2->io_lock, 1) < 0) {
83 op->error = -ERESTARTSYS;
84 op->flags |= AFS_OPERATION_STOP;
85 mutex_unlock(&vnode->io_lock);
86 op->flags &= ~AFS_OPERATION_LOCK_0;
87 _leave(" = f [I 1]");
88 return false;
89 }
90 op->flags |= AFS_OPERATION_LOCK_1;
91 }
92
93 _leave(" = t [2]");
94 return true;
95 }
96
afs_drop_io_locks(struct afs_operation * op)97 static void afs_drop_io_locks(struct afs_operation *op)
98 {
99 struct afs_vnode *vnode = op->file[0].vnode;
100 struct afs_vnode *vnode2 = op->file[1].vnode;
101
102 _enter("");
103
104 if (op->flags & AFS_OPERATION_LOCK_1)
105 mutex_unlock(&vnode2->io_lock);
106 if (op->flags & AFS_OPERATION_LOCK_0)
107 mutex_unlock(&vnode->io_lock);
108 }
109
afs_prepare_vnode(struct afs_operation * op,struct afs_vnode_param * vp,unsigned int index)110 static void afs_prepare_vnode(struct afs_operation *op, struct afs_vnode_param *vp,
111 unsigned int index)
112 {
113 struct afs_vnode *vnode = vp->vnode;
114
115 if (vnode) {
116 vp->fid = vnode->fid;
117 vp->dv_before = vnode->status.data_version;
118 vp->cb_break_before = afs_calc_vnode_cb_break(vnode);
119 if (vnode->lock_state != AFS_VNODE_LOCK_NONE)
120 op->flags |= AFS_OPERATION_CUR_ONLY;
121 if (vp->modification)
122 set_bit(AFS_VNODE_MODIFYING, &vnode->flags);
123 }
124
125 if (vp->fid.vnode)
126 _debug("PREP[%u] {%llx:%llu.%u}",
127 index, vp->fid.vid, vp->fid.vnode, vp->fid.unique);
128 }
129
130 /*
131 * Begin an operation on the fileserver.
132 *
133 * Fileserver operations are serialised on the server by vnode, so we serialise
134 * them here also using the io_lock.
135 */
afs_begin_vnode_operation(struct afs_operation * op)136 bool afs_begin_vnode_operation(struct afs_operation *op)
137 {
138 struct afs_vnode *vnode = op->file[0].vnode;
139
140 ASSERT(vnode);
141
142 _enter("");
143
144 if (op->file[0].need_io_lock)
145 if (!afs_get_io_locks(op))
146 return false;
147
148 afs_prepare_vnode(op, &op->file[0], 0);
149 afs_prepare_vnode(op, &op->file[1], 1);
150 op->cb_v_break = op->volume->cb_v_break;
151 _leave(" = true");
152 return true;
153 }
154
155 /*
156 * Tidy up a filesystem cursor and unlock the vnode.
157 */
afs_end_vnode_operation(struct afs_operation * op)158 static void afs_end_vnode_operation(struct afs_operation *op)
159 {
160 _enter("");
161
162 if (op->error == -EDESTADDRREQ ||
163 op->error == -EADDRNOTAVAIL ||
164 op->error == -ENETUNREACH ||
165 op->error == -EHOSTUNREACH)
166 afs_dump_edestaddrreq(op);
167
168 afs_drop_io_locks(op);
169
170 if (op->error == -ECONNABORTED)
171 op->error = afs_abort_to_error(op->ac.abort_code);
172 }
173
174 /*
175 * Wait for an in-progress operation to complete.
176 */
afs_wait_for_operation(struct afs_operation * op)177 void afs_wait_for_operation(struct afs_operation *op)
178 {
179 _enter("");
180
181 while (afs_select_fileserver(op)) {
182 op->cb_s_break = op->server->cb_s_break;
183 if (test_bit(AFS_SERVER_FL_IS_YFS, &op->server->flags) &&
184 op->ops->issue_yfs_rpc)
185 op->ops->issue_yfs_rpc(op);
186 else if (op->ops->issue_afs_rpc)
187 op->ops->issue_afs_rpc(op);
188 else
189 op->ac.error = -ENOTSUPP;
190
191 if (op->call)
192 op->error = afs_wait_for_call_to_complete(op->call, &op->ac);
193 }
194
195 switch (op->error) {
196 case 0:
197 _debug("success");
198 op->ops->success(op);
199 break;
200 case -ECONNABORTED:
201 if (op->ops->aborted)
202 op->ops->aborted(op);
203 fallthrough;
204 default:
205 if (op->ops->failed)
206 op->ops->failed(op);
207 break;
208 }
209
210 afs_end_vnode_operation(op);
211
212 if (op->error == 0 && op->ops->edit_dir) {
213 _debug("edit_dir");
214 op->ops->edit_dir(op);
215 }
216 _leave("");
217 }
218
219 /*
220 * Dispose of an operation.
221 */
afs_put_operation(struct afs_operation * op)222 int afs_put_operation(struct afs_operation *op)
223 {
224 int i, ret = op->error;
225
226 _enter("op=%08x,%d", op->debug_id, ret);
227
228 if (op->ops && op->ops->put)
229 op->ops->put(op);
230 if (op->file[0].modification)
231 clear_bit(AFS_VNODE_MODIFYING, &op->file[0].vnode->flags);
232 if (op->file[1].modification && op->file[1].vnode != op->file[0].vnode)
233 clear_bit(AFS_VNODE_MODIFYING, &op->file[1].vnode->flags);
234 if (op->file[0].put_vnode)
235 iput(&op->file[0].vnode->vfs_inode);
236 if (op->file[1].put_vnode)
237 iput(&op->file[1].vnode->vfs_inode);
238
239 if (op->more_files) {
240 for (i = 0; i < op->nr_files - 2; i++)
241 if (op->more_files[i].put_vnode)
242 iput(&op->more_files[i].vnode->vfs_inode);
243 kfree(op->more_files);
244 }
245
246 afs_end_cursor(&op->ac);
247 afs_put_serverlist(op->net, op->server_list);
248 afs_put_volume(op->net, op->volume, afs_volume_trace_put_put_op);
249 key_put(op->key);
250 kfree(op);
251 return ret;
252 }
253
afs_do_sync_operation(struct afs_operation * op)254 int afs_do_sync_operation(struct afs_operation *op)
255 {
256 afs_begin_vnode_operation(op);
257 afs_wait_for_operation(op);
258 return afs_put_operation(op);
259 }
260