1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
commit e7c0c3fa29280d62aa5e11101a674bb3064bd791
Author: NeilBrown <neilb@suse.de>
Date: Thu Nov 22 14:42:49 2012 +1100
md/raid10: close race that lose writes lost when replacement completes.
When a replacement operation completes there is a small window
when the original device is marked 'faulty' and the replacement
still looks like a replacement. The faulty should be removed and
the replacement moved in place very quickly, bit it isn't instant.
So the code write out to the array must handle the possibility that
the only working device for some slot in the replacement - but it
doesn't. If the primary device is faulty it just gives up. This
can lead to corruption.
So make the code more robust: if either the primary or the
replacement is present and working, write to them. Only when
neither are present do we give up.
This bug has been present since replacement was introduced in
3.3, so it is suitable for any -stable kernel since then.
Reported-by: "George Spelvin" <linux@horizon.com>
Cc: stable@vger.kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index d1295af..ad03251 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1334,18 +1334,21 @@ retry_write:
blocked_rdev = rrdev;
break;
}
+ if (rdev && (test_bit(Faulty, &rdev->flags)
+ || test_bit(Unmerged, &rdev->flags)))
+ rdev = NULL;
if (rrdev && (test_bit(Faulty, &rrdev->flags)
|| test_bit(Unmerged, &rrdev->flags)))
rrdev = NULL;
r10_bio->devs[i].bio = NULL;
r10_bio->devs[i].repl_bio = NULL;
- if (!rdev || test_bit(Faulty, &rdev->flags) ||
- test_bit(Unmerged, &rdev->flags)) {
+
+ if (!rdev && !rrdev) {
set_bit(R10BIO_Degraded, &r10_bio->state);
continue;
}
- if (test_bit(WriteErrorSeen, &rdev->flags)) {
+ if (rdev && test_bit(WriteErrorSeen, &rdev->flags)) {
sector_t first_bad;
sector_t dev_sector = r10_bio->devs[i].addr;
int bad_sectors;
@@ -1387,8 +1390,10 @@ retry_write:
max_sectors = good_sectors;
}
}
- r10_bio->devs[i].bio = bio;
- atomic_inc(&rdev->nr_pending);
+ if (rdev) {
+ r10_bio->devs[i].bio = bio;
+ atomic_inc(&rdev->nr_pending);
+ }
if (rrdev) {
r10_bio->devs[i].repl_bio = bio;
atomic_inc(&rrdev->nr_pending);
@@ -1444,69 +1449,71 @@ retry_write:
for (i = 0; i < conf->copies; i++) {
struct bio *mbio;
int d = r10_bio->devs[i].devnum;
- if (!r10_bio->devs[i].bio)
- continue;
+ if (r10_bio->devs[i].bio) {
+ struct md_rdev *rdev = conf->mirrors[d].rdev;
+ mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
+ r10_bio->devs[i].bio = mbio;
+
+ mbio->bi_sector = (r10_bio->devs[i].addr+
+ choose_data_offset(r10_bio,
+ rdev));
+ mbio->bi_bdev = rdev->bdev;
+ mbio->bi_end_io = raid10_end_write_request;
+ mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
+ mbio->bi_private = r10_bio;
- mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
- max_sectors);
- r10_bio->devs[i].bio = mbio;
+ atomic_inc(&r10_bio->remaining);
- mbio->bi_sector = (r10_bio->devs[i].addr+
- choose_data_offset(r10_bio,
- conf->mirrors[d].rdev));
- mbio->bi_bdev = conf->mirrors[d].rdev->bdev;
- mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
- mbio->bi_private = r10_bio;
+ cb = blk_check_plugged(raid10_unplug, mddev,
+ sizeof(*plug));
+ if (cb)
+ plug = container_of(cb, struct raid10_plug_cb,
+ cb);
+ else
+ plug = NULL;
+ spin_lock_irqsave(&conf->device_lock, flags);
+ if (plug) {
+ bio_list_add(&plug->pending, mbio);
+ plug->pending_cnt++;
+ } else {
+ bio_list_add(&conf->pending_bio_list, mbio);
+ conf->pending_count++;
+ }
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ if (!plug)
+ md_wakeup_thread(mddev->thread);
+ }
- atomic_inc(&r10_bio->remaining);
+ if (r10_bio->devs[i].repl_bio) {
+ struct md_rdev *rdev = conf->mirrors[d].replacement;
+ if (rdev == NULL) {
+ /* Replacement just got moved to main 'rdev' */
+ smp_mb();
+ rdev = conf->mirrors[d].rdev;
+ }
+ mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
+ md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
+ max_sectors);
+ r10_bio->devs[i].repl_bio = mbio;
+
+ mbio->bi_sector = (r10_bio->devs[i].addr +
+ choose_data_offset(
+ r10_bio, rdev));
+ mbio->bi_bdev = rdev->bdev;
+ mbio->bi_end_io = raid10_end_write_request;
+ mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
+ mbio->bi_private = r10_bio;
- cb = blk_check_plugged(raid10_unplug, mddev, sizeof(*plug));
- if (cb)
- plug = container_of(cb, struct raid10_plug_cb, cb);
- else
- plug = NULL;
- spin_lock_irqsave(&conf->device_lock, flags);
- if (plug) {
- bio_list_add(&plug->pending, mbio);
- plug->pending_cnt++;
- } else {
+ atomic_inc(&r10_bio->remaining);
+ spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
conf->pending_count++;
+ spin_unlock_irqrestore(&conf->device_lock, flags);
+ if (!mddev_check_plugged(mddev))
+ md_wakeup_thread(mddev->thread);
}
- spin_unlock_irqrestore(&conf->device_lock, flags);
- if (!plug)
- md_wakeup_thread(mddev->thread);
-
- if (!r10_bio->devs[i].repl_bio)
- continue;
-
- mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- md_trim_bio(mbio, r10_bio->sector - bio->bi_sector,
- max_sectors);
- r10_bio->devs[i].repl_bio = mbio;
-
- /* We are actively writing to the original device
- * so it cannot disappear, so the replacement cannot
- * become NULL here
- */
- mbio->bi_sector = (r10_bio->devs[i].addr +
- choose_data_offset(
- r10_bio,
- conf->mirrors[d].replacement));
- mbio->bi_bdev = conf->mirrors[d].replacement->bdev;
- mbio->bi_end_io = raid10_end_write_request;
- mbio->bi_rw = WRITE | do_sync | do_fua | do_discard;
- mbio->bi_private = r10_bio;
-
- atomic_inc(&r10_bio->remaining);
- spin_lock_irqsave(&conf->device_lock, flags);
- bio_list_add(&conf->pending_bio_list, mbio);
- conf->pending_count++;
- spin_unlock_irqrestore(&conf->device_lock, flags);
- if (!mddev_check_plugged(mddev))
- md_wakeup_thread(mddev->thread);
}
/* Don't remove the bias on 'remaining' (one_write_done) until
|
