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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* AFS volume management
3 *
4 * Copyright (C) 2002, 2007 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 "internal.h"
11
12unsigned __read_mostly afs_volume_gc_delay = 10;
13unsigned __read_mostly afs_volume_record_life = 60 * 60;
14
15/*
16 * Insert a volume into a cell. If there's an existing volume record, that is
17 * returned instead with a ref held.
18 */
19static struct afs_volume *afs_insert_volume_into_cell(struct afs_cell *cell,
20 struct afs_volume *volume)
21{
22 struct afs_volume *p;
23 struct rb_node *parent = NULL, **pp;
24
25 write_seqlock(&cell->volume_lock);
26
27 pp = &cell->volumes.rb_node;
28 while (*pp) {
29 parent = *pp;
30 p = rb_entry(parent, struct afs_volume, cell_node);
31 if (p->vid < volume->vid) {
32 pp = &(*pp)->rb_left;
33 } else if (p->vid > volume->vid) {
34 pp = &(*pp)->rb_right;
35 } else {
36 volume = afs_get_volume(p, afs_volume_trace_get_cell_insert);
37 goto found;
38 }
39 }
40
41 rb_link_node_rcu(&volume->cell_node, parent, pp);
42 rb_insert_color(&volume->cell_node, &cell->volumes);
43 hlist_add_head_rcu(&volume->proc_link, &cell->proc_volumes);
44
45found:
46 write_sequnlock(&cell->volume_lock);
47 return volume;
48
49}
50
51static void afs_remove_volume_from_cell(struct afs_volume *volume)
52{
53 struct afs_cell *cell = volume->cell;
54
55 if (!hlist_unhashed(&volume->proc_link)) {
56 trace_afs_volume(volume->vid, atomic_read(&volume->usage),
57 afs_volume_trace_remove);
58 write_seqlock(&cell->volume_lock);
59 hlist_del_rcu(&volume->proc_link);
60 rb_erase(&volume->cell_node, &cell->volumes);
61 write_sequnlock(&cell->volume_lock);
62 }
63}
64
65/*
66 * Allocate a volume record and load it up from a vldb record.
67 */
68static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params,
69 struct afs_vldb_entry *vldb,
70 unsigned long type_mask)
71{
72 struct afs_server_list *slist;
73 struct afs_volume *volume;
74 int ret = -ENOMEM, nr_servers = 0, i;
75
76 for (i = 0; i < vldb->nr_servers; i++)
77 if (vldb->fs_mask[i] & type_mask)
78 nr_servers++;
79
80 volume = kzalloc(sizeof(struct afs_volume), GFP_KERNEL);
81 if (!volume)
82 goto error_0;
83
84 volume->vid = vldb->vid[params->type];
85 volume->update_at = ktime_get_real_seconds() + afs_volume_record_life;
86 volume->cell = afs_get_cell(params->cell);
87 volume->type = params->type;
88 volume->type_force = params->force;
89 volume->name_len = vldb->name_len;
90
91 atomic_set(&volume->usage, 1);
92 INIT_HLIST_NODE(&volume->proc_link);
93 rwlock_init(&volume->servers_lock);
94 rwlock_init(&volume->cb_v_break_lock);
95 memcpy(volume->name, vldb->name, vldb->name_len + 1);
96
97 slist = afs_alloc_server_list(params->cell, params->key, vldb, type_mask);
98 if (IS_ERR(slist)) {
99 ret = PTR_ERR(slist);
100 goto error_1;
101 }
102
103 refcount_set(&slist->usage, 1);
104 rcu_assign_pointer(volume->servers, slist);
105 trace_afs_volume(volume->vid, 1, afs_volume_trace_alloc);
106 return volume;
107
108error_1:
109 afs_put_cell(params->net, volume->cell);
110 kfree(volume);
111error_0:
112 return ERR_PTR(ret);
113}
114
115/*
116 * Look up or allocate a volume record.
117 */
118static struct afs_volume *afs_lookup_volume(struct afs_fs_context *params,
119 struct afs_vldb_entry *vldb,
120 unsigned long type_mask)
121{
122 struct afs_volume *candidate, *volume;
123
124 candidate = afs_alloc_volume(params, vldb, type_mask);
125 if (IS_ERR(candidate))
126 return candidate;
127
128 volume = afs_insert_volume_into_cell(params->cell, candidate);
129 if (volume != candidate)
130 afs_put_volume(params->net, candidate, afs_volume_trace_put_cell_dup);
131 return volume;
132}
133
134/*
135 * Look up a VLDB record for a volume.
136 */
137static struct afs_vldb_entry *afs_vl_lookup_vldb(struct afs_cell *cell,
138 struct key *key,
139 const char *volname,
140 size_t volnamesz)
141{
142 struct afs_vldb_entry *vldb = ERR_PTR(-EDESTADDRREQ);
143 struct afs_vl_cursor vc;
144 int ret;
145
146 if (!afs_begin_vlserver_operation(&vc, cell, key))
147 return ERR_PTR(-ERESTARTSYS);
148
149 while (afs_select_vlserver(&vc)) {
150 vldb = afs_vl_get_entry_by_name_u(&vc, volname, volnamesz);
151 }
152
153 ret = afs_end_vlserver_operation(&vc);
154 return ret < 0 ? ERR_PTR(ret) : vldb;
155}
156
157/*
158 * Look up a volume in the VL server and create a candidate volume record for
159 * it.
160 *
161 * The volume name can be one of the following:
162 * "%[cell:]volume[.]" R/W volume
163 * "#[cell:]volume[.]" R/O or R/W volume (rwparent=0),
164 * or R/W (rwparent=1) volume
165 * "%[cell:]volume.readonly" R/O volume
166 * "#[cell:]volume.readonly" R/O volume
167 * "%[cell:]volume.backup" Backup volume
168 * "#[cell:]volume.backup" Backup volume
169 *
170 * The cell name is optional, and defaults to the current cell.
171 *
172 * See "The Rules of Mount Point Traversal" in Chapter 5 of the AFS SysAdmin
173 * Guide
174 * - Rule 1: Explicit type suffix forces access of that type or nothing
175 * (no suffix, then use Rule 2 & 3)
176 * - Rule 2: If parent volume is R/O, then mount R/O volume by preference, R/W
177 * if not available
178 * - Rule 3: If parent volume is R/W, then only mount R/W volume unless
179 * explicitly told otherwise
180 */
181struct afs_volume *afs_create_volume(struct afs_fs_context *params)
182{
183 struct afs_vldb_entry *vldb;
184 struct afs_volume *volume;
185 unsigned long type_mask = 1UL << params->type;
186
187 vldb = afs_vl_lookup_vldb(params->cell, params->key,
188 params->volname, params->volnamesz);
189 if (IS_ERR(vldb))
190 return ERR_CAST(vldb);
191
192 if (test_bit(AFS_VLDB_QUERY_ERROR, &vldb->flags)) {
193 volume = ERR_PTR(vldb->error);
194 goto error;
195 }
196
197 /* Make the final decision on the type we want */
198 volume = ERR_PTR(-ENOMEDIUM);
199 if (params->force) {
200 if (!(vldb->flags & type_mask))
201 goto error;
202 } else if (test_bit(AFS_VLDB_HAS_RO, &vldb->flags)) {
203 params->type = AFSVL_ROVOL;
204 } else if (test_bit(AFS_VLDB_HAS_RW, &vldb->flags)) {
205 params->type = AFSVL_RWVOL;
206 } else {
207 goto error;
208 }
209
210 type_mask = 1UL << params->type;
211 volume = afs_lookup_volume(params, vldb, type_mask);
212
213error:
214 kfree(vldb);
215 return volume;
216}
217
218/*
219 * Destroy a volume record
220 */
221static void afs_destroy_volume(struct afs_net *net, struct afs_volume *volume)
222{
223 _enter("%p", volume);
224
225#ifdef CONFIG_AFS_FSCACHE
226 ASSERTCMP(volume->cache, ==, NULL);
227#endif
228
229 afs_remove_volume_from_cell(volume);
230 afs_put_serverlist(net, rcu_access_pointer(volume->servers));
231 afs_put_cell(net, volume->cell);
232 trace_afs_volume(volume->vid, atomic_read(&volume->usage),
233 afs_volume_trace_free);
234 kfree_rcu(volume, rcu);
235
236 _leave(" [destroyed]");
237}
238
239/*
240 * Get a reference on a volume record.
241 */
242struct afs_volume *afs_get_volume(struct afs_volume *volume,
243 enum afs_volume_trace reason)
244{
245 if (volume) {
246 int u = atomic_inc_return(&volume->usage);
247 trace_afs_volume(volume->vid, u, reason);
248 }
249 return volume;
250}
251
252
253/*
254 * Drop a reference on a volume record.
255 */
256void afs_put_volume(struct afs_net *net, struct afs_volume *volume,
257 enum afs_volume_trace reason)
258{
259 if (volume) {
260 afs_volid_t vid = volume->vid;
261 int u = atomic_dec_return(&volume->usage);
262 trace_afs_volume(vid, u, reason);
263 if (u == 0)
264 afs_destroy_volume(net, volume);
265 }
266}
267
268/*
269 * Activate a volume.
270 */
271void afs_activate_volume(struct afs_volume *volume)
272{
273#ifdef CONFIG_AFS_FSCACHE
274 volume->cache = fscache_acquire_cookie(volume->cell->cache,
275 &afs_volume_cache_index_def,
276 &volume->vid, sizeof(volume->vid),
277 NULL, 0,
278 volume, 0, true);
279#endif
280}
281
282/*
283 * Deactivate a volume.
284 */
285void afs_deactivate_volume(struct afs_volume *volume)
286{
287 _enter("%s", volume->name);
288
289#ifdef CONFIG_AFS_FSCACHE
290 fscache_relinquish_cookie(volume->cache, NULL,
291 test_bit(AFS_VOLUME_DELETED, &volume->flags));
292 volume->cache = NULL;
293#endif
294
295 _leave("");
296}
297
298/*
299 * Query the VL service to update the volume status.
300 */
301static int afs_update_volume_status(struct afs_volume *volume, struct key *key)
302{
303 struct afs_server_list *new, *old, *discard;
304 struct afs_vldb_entry *vldb;
305 char idbuf[16];
306 int ret, idsz;
307
308 _enter("");
309
310 /* We look up an ID by passing it as a decimal string in the
311 * operation's name parameter.
312 */
313 idsz = sprintf(idbuf, "%llu", volume->vid);
314
315 vldb = afs_vl_lookup_vldb(volume->cell, key, idbuf, idsz);
316 if (IS_ERR(vldb)) {
317 ret = PTR_ERR(vldb);
318 goto error;
319 }
320
321 /* See if the volume got renamed. */
322 if (vldb->name_len != volume->name_len ||
323 memcmp(vldb->name, volume->name, vldb->name_len) != 0) {
324 /* TODO: Use RCU'd string. */
325 memcpy(volume->name, vldb->name, AFS_MAXVOLNAME);
326 volume->name_len = vldb->name_len;
327 }
328
329 /* See if the volume's server list got updated. */
330 new = afs_alloc_server_list(volume->cell, key,
331 vldb, (1 << volume->type));
332 if (IS_ERR(new)) {
333 ret = PTR_ERR(new);
334 goto error_vldb;
335 }
336
337 write_lock(&volume->servers_lock);
338
339 discard = new;
340 old = rcu_dereference_protected(volume->servers,
341 lockdep_is_held(&volume->servers_lock));
342 if (afs_annotate_server_list(new, old)) {
343 new->seq = volume->servers_seq + 1;
344 rcu_assign_pointer(volume->servers, new);
345 smp_wmb();
346 volume->servers_seq++;
347 discard = old;
348 }
349
350 volume->update_at = ktime_get_real_seconds() + afs_volume_record_life;
351 write_unlock(&volume->servers_lock);
352 ret = 0;
353
354 afs_put_serverlist(volume->cell->net, discard);
355error_vldb:
356 kfree(vldb);
357error:
358 _leave(" = %d", ret);
359 return ret;
360}
361
362/*
363 * Make sure the volume record is up to date.
364 */
365int afs_check_volume_status(struct afs_volume *volume, struct afs_operation *op)
366{
367 int ret, retries = 0;
368
369 _enter("");
370
371retry:
372 if (test_bit(AFS_VOLUME_WAIT, &volume->flags))
373 goto wait;
374 if (volume->update_at <= ktime_get_real_seconds() ||
375 test_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags))
376 goto update;
377 _leave(" = 0");
378 return 0;
379
380update:
381 if (!test_and_set_bit_lock(AFS_VOLUME_UPDATING, &volume->flags)) {
382 clear_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags);
383 ret = afs_update_volume_status(volume, op->key);
384 if (ret < 0)
385 set_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags);
386 clear_bit_unlock(AFS_VOLUME_WAIT, &volume->flags);
387 clear_bit_unlock(AFS_VOLUME_UPDATING, &volume->flags);
388 wake_up_bit(&volume->flags, AFS_VOLUME_WAIT);
389 _leave(" = %d", ret);
390 return ret;
391 }
392
393wait:
394 if (!test_bit(AFS_VOLUME_WAIT, &volume->flags)) {
395 _leave(" = 0 [no wait]");
396 return 0;
397 }
398
399 ret = wait_on_bit(&volume->flags, AFS_VOLUME_WAIT,
400 (op->flags & AFS_OPERATION_UNINTR) ?
401 TASK_UNINTERRUPTIBLE : TASK_INTERRUPTIBLE);
402 if (ret == -ERESTARTSYS) {
403 _leave(" = %d", ret);
404 return ret;
405 }
406
407 retries++;
408 if (retries == 4) {
409 _leave(" = -ESTALE");
410 return -ESTALE;
411 }
412 goto retry;
413}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* AFS volume management
3 *
4 * Copyright (C) 2002, 2007 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 "internal.h"
11
12unsigned __read_mostly afs_volume_gc_delay = 10;
13unsigned __read_mostly afs_volume_record_life = 60 * 60;
14
15/*
16 * Allocate a volume record and load it up from a vldb record.
17 */
18static struct afs_volume *afs_alloc_volume(struct afs_fs_context *params,
19 struct afs_vldb_entry *vldb,
20 unsigned long type_mask)
21{
22 struct afs_server_list *slist;
23 struct afs_volume *volume;
24 int ret = -ENOMEM, nr_servers = 0, i;
25
26 for (i = 0; i < vldb->nr_servers; i++)
27 if (vldb->fs_mask[i] & type_mask)
28 nr_servers++;
29
30 volume = kzalloc(sizeof(struct afs_volume), GFP_KERNEL);
31 if (!volume)
32 goto error_0;
33
34 volume->vid = vldb->vid[params->type];
35 volume->update_at = ktime_get_real_seconds() + afs_volume_record_life;
36 volume->cell = afs_get_cell(params->cell);
37 volume->type = params->type;
38 volume->type_force = params->force;
39 volume->name_len = vldb->name_len;
40
41 atomic_set(&volume->usage, 1);
42 INIT_LIST_HEAD(&volume->proc_link);
43 rwlock_init(&volume->servers_lock);
44 rwlock_init(&volume->cb_v_break_lock);
45 memcpy(volume->name, vldb->name, vldb->name_len + 1);
46
47 slist = afs_alloc_server_list(params->cell, params->key, vldb, type_mask);
48 if (IS_ERR(slist)) {
49 ret = PTR_ERR(slist);
50 goto error_1;
51 }
52
53 refcount_set(&slist->usage, 1);
54 volume->servers = slist;
55 return volume;
56
57error_1:
58 afs_put_cell(params->net, volume->cell);
59 kfree(volume);
60error_0:
61 return ERR_PTR(ret);
62}
63
64/*
65 * Look up a VLDB record for a volume.
66 */
67static struct afs_vldb_entry *afs_vl_lookup_vldb(struct afs_cell *cell,
68 struct key *key,
69 const char *volname,
70 size_t volnamesz)
71{
72 struct afs_vldb_entry *vldb = ERR_PTR(-EDESTADDRREQ);
73 struct afs_vl_cursor vc;
74 int ret;
75
76 if (!afs_begin_vlserver_operation(&vc, cell, key))
77 return ERR_PTR(-ERESTARTSYS);
78
79 while (afs_select_vlserver(&vc)) {
80 vldb = afs_vl_get_entry_by_name_u(&vc, volname, volnamesz);
81 }
82
83 ret = afs_end_vlserver_operation(&vc);
84 return ret < 0 ? ERR_PTR(ret) : vldb;
85}
86
87/*
88 * Look up a volume in the VL server and create a candidate volume record for
89 * it.
90 *
91 * The volume name can be one of the following:
92 * "%[cell:]volume[.]" R/W volume
93 * "#[cell:]volume[.]" R/O or R/W volume (rwparent=0),
94 * or R/W (rwparent=1) volume
95 * "%[cell:]volume.readonly" R/O volume
96 * "#[cell:]volume.readonly" R/O volume
97 * "%[cell:]volume.backup" Backup volume
98 * "#[cell:]volume.backup" Backup volume
99 *
100 * The cell name is optional, and defaults to the current cell.
101 *
102 * See "The Rules of Mount Point Traversal" in Chapter 5 of the AFS SysAdmin
103 * Guide
104 * - Rule 1: Explicit type suffix forces access of that type or nothing
105 * (no suffix, then use Rule 2 & 3)
106 * - Rule 2: If parent volume is R/O, then mount R/O volume by preference, R/W
107 * if not available
108 * - Rule 3: If parent volume is R/W, then only mount R/W volume unless
109 * explicitly told otherwise
110 */
111struct afs_volume *afs_create_volume(struct afs_fs_context *params)
112{
113 struct afs_vldb_entry *vldb;
114 struct afs_volume *volume;
115 unsigned long type_mask = 1UL << params->type;
116
117 vldb = afs_vl_lookup_vldb(params->cell, params->key,
118 params->volname, params->volnamesz);
119 if (IS_ERR(vldb))
120 return ERR_CAST(vldb);
121
122 if (test_bit(AFS_VLDB_QUERY_ERROR, &vldb->flags)) {
123 volume = ERR_PTR(vldb->error);
124 goto error;
125 }
126
127 /* Make the final decision on the type we want */
128 volume = ERR_PTR(-ENOMEDIUM);
129 if (params->force) {
130 if (!(vldb->flags & type_mask))
131 goto error;
132 } else if (test_bit(AFS_VLDB_HAS_RO, &vldb->flags)) {
133 params->type = AFSVL_ROVOL;
134 } else if (test_bit(AFS_VLDB_HAS_RW, &vldb->flags)) {
135 params->type = AFSVL_RWVOL;
136 } else {
137 goto error;
138 }
139
140 type_mask = 1UL << params->type;
141 volume = afs_alloc_volume(params, vldb, type_mask);
142
143error:
144 kfree(vldb);
145 return volume;
146}
147
148/*
149 * Destroy a volume record
150 */
151static void afs_destroy_volume(struct afs_net *net, struct afs_volume *volume)
152{
153 _enter("%p", volume);
154
155#ifdef CONFIG_AFS_FSCACHE
156 ASSERTCMP(volume->cache, ==, NULL);
157#endif
158
159 afs_put_serverlist(net, volume->servers);
160 afs_put_cell(net, volume->cell);
161 kfree(volume);
162
163 _leave(" [destroyed]");
164}
165
166/*
167 * Drop a reference on a volume record.
168 */
169void afs_put_volume(struct afs_cell *cell, struct afs_volume *volume)
170{
171 if (volume) {
172 _enter("%s", volume->name);
173
174 if (atomic_dec_and_test(&volume->usage))
175 afs_destroy_volume(cell->net, volume);
176 }
177}
178
179/*
180 * Activate a volume.
181 */
182void afs_activate_volume(struct afs_volume *volume)
183{
184#ifdef CONFIG_AFS_FSCACHE
185 volume->cache = fscache_acquire_cookie(volume->cell->cache,
186 &afs_volume_cache_index_def,
187 &volume->vid, sizeof(volume->vid),
188 NULL, 0,
189 volume, 0, true);
190#endif
191
192 write_lock(&volume->cell->proc_lock);
193 list_add_tail(&volume->proc_link, &volume->cell->proc_volumes);
194 write_unlock(&volume->cell->proc_lock);
195}
196
197/*
198 * Deactivate a volume.
199 */
200void afs_deactivate_volume(struct afs_volume *volume)
201{
202 _enter("%s", volume->name);
203
204 write_lock(&volume->cell->proc_lock);
205 list_del_init(&volume->proc_link);
206 write_unlock(&volume->cell->proc_lock);
207
208#ifdef CONFIG_AFS_FSCACHE
209 fscache_relinquish_cookie(volume->cache, NULL,
210 test_bit(AFS_VOLUME_DELETED, &volume->flags));
211 volume->cache = NULL;
212#endif
213
214 _leave("");
215}
216
217/*
218 * Query the VL service to update the volume status.
219 */
220static int afs_update_volume_status(struct afs_volume *volume, struct key *key)
221{
222 struct afs_server_list *new, *old, *discard;
223 struct afs_vldb_entry *vldb;
224 char idbuf[16];
225 int ret, idsz;
226
227 _enter("");
228
229 /* We look up an ID by passing it as a decimal string in the
230 * operation's name parameter.
231 */
232 idsz = sprintf(idbuf, "%llu", volume->vid);
233
234 vldb = afs_vl_lookup_vldb(volume->cell, key, idbuf, idsz);
235 if (IS_ERR(vldb)) {
236 ret = PTR_ERR(vldb);
237 goto error;
238 }
239
240 /* See if the volume got renamed. */
241 if (vldb->name_len != volume->name_len ||
242 memcmp(vldb->name, volume->name, vldb->name_len) != 0) {
243 /* TODO: Use RCU'd string. */
244 memcpy(volume->name, vldb->name, AFS_MAXVOLNAME);
245 volume->name_len = vldb->name_len;
246 }
247
248 /* See if the volume's server list got updated. */
249 new = afs_alloc_server_list(volume->cell, key,
250 vldb, (1 << volume->type));
251 if (IS_ERR(new)) {
252 ret = PTR_ERR(new);
253 goto error_vldb;
254 }
255
256 write_lock(&volume->servers_lock);
257
258 discard = new;
259 old = volume->servers;
260 if (afs_annotate_server_list(new, old)) {
261 new->seq = volume->servers_seq + 1;
262 volume->servers = new;
263 smp_wmb();
264 volume->servers_seq++;
265 discard = old;
266 }
267
268 volume->update_at = ktime_get_real_seconds() + afs_volume_record_life;
269 clear_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags);
270 write_unlock(&volume->servers_lock);
271 ret = 0;
272
273 afs_put_serverlist(volume->cell->net, discard);
274error_vldb:
275 kfree(vldb);
276error:
277 _leave(" = %d", ret);
278 return ret;
279}
280
281/*
282 * Make sure the volume record is up to date.
283 */
284int afs_check_volume_status(struct afs_volume *volume, struct key *key)
285{
286 time64_t now = ktime_get_real_seconds();
287 int ret, retries = 0;
288
289 _enter("");
290
291 if (volume->update_at <= now)
292 set_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags);
293
294retry:
295 if (!test_bit(AFS_VOLUME_NEEDS_UPDATE, &volume->flags) &&
296 !test_bit(AFS_VOLUME_WAIT, &volume->flags)) {
297 _leave(" = 0");
298 return 0;
299 }
300
301 if (!test_and_set_bit_lock(AFS_VOLUME_UPDATING, &volume->flags)) {
302 ret = afs_update_volume_status(volume, key);
303 clear_bit_unlock(AFS_VOLUME_WAIT, &volume->flags);
304 clear_bit_unlock(AFS_VOLUME_UPDATING, &volume->flags);
305 wake_up_bit(&volume->flags, AFS_VOLUME_WAIT);
306 _leave(" = %d", ret);
307 return ret;
308 }
309
310 if (!test_bit(AFS_VOLUME_WAIT, &volume->flags)) {
311 _leave(" = 0 [no wait]");
312 return 0;
313 }
314
315 ret = wait_on_bit(&volume->flags, AFS_VOLUME_WAIT, TASK_INTERRUPTIBLE);
316 if (ret == -ERESTARTSYS) {
317 _leave(" = %d", ret);
318 return ret;
319 }
320
321 retries++;
322 if (retries == 4) {
323 _leave(" = -ESTALE");
324 return -ESTALE;
325 }
326 goto retry;
327}