We need to hold a reference to rdevs while reading and writing to attempt to correct read errors. This reference must be taken under an rcu lock.
Signed-off-by: Neil Brown <[EMAIL PROTECTED]>
### Diffstat output
./drivers/md/raid10.c | 44 ++++++++++++++++++++++++++++++--------------
1 file changed, 30 insertions(+), 14 deletions(-)
diff ./drivers/md/raid10.c~current~ ./drivers/md/raid10.c
--- ./drivers/md/raid10.c~current~ 2006-04-28 12:13:20.000000000 +1000
+++ ./drivers/md/raid10.c 2006-04-28 12:16:54.000000000 +1000
@@ -1407,36 +1407,45 @@ static void raid10d(mddev_t *mddev)
if (s > (PAGE_SIZE>>9))
s = PAGE_SIZE >> 9;
+ rcu_read_lock();
do {
int d = r10_bio->devs[sl].devnum;
- rdev = conf->mirrors[d].rdev;
+ rdev =
rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
- test_bit(In_sync, &rdev->flags) &&
- sync_page_io(rdev->bdev,
- r10_bio->devs[sl].addr
+
- sect +
rdev->data_offset,
- s<<9,
- conf->tmppage, READ))
- success = 1;
- else {
- sl++;
- if (sl == conf->copies)
- sl = 0;
+ test_bit(In_sync, &rdev->flags)) {
+ atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
+ success =
sync_page_io(rdev->bdev,
+
r10_bio->devs[sl].addr +
+ sect +
rdev->data_offset,
+ s<<9,
+
conf->tmppage, READ);
+ rdev_dec_pending(rdev, mddev);
+ rcu_read_lock();
+ if (success)
+ break;
}
+ sl++;
+ if (sl == conf->copies)
+ sl = 0;
} while (!success && sl != r10_bio->read_slot);
+ rcu_read_unlock();
if (success) {
int start = sl;
/* write it back and re-read */
+ rcu_read_lock();
while (sl != r10_bio->read_slot) {
int d;
if (sl==0)
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
- rdev = conf->mirrors[d].rdev;
+ rdev =
rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
test_bit(In_sync,
&rdev->flags)) {
+
atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
atomic_add(s,
&rdev->corrected_errors);
if
(sync_page_io(rdev->bdev,
r10_bio->devs[sl].addr +
@@ -1444,6 +1453,8 @@ static void raid10d(mddev_t *mddev)
s<<9,
conf->tmppage, WRITE) == 0)
/* Well, this
device is dead */
md_error(mddev,
rdev);
+ rdev_dec_pending(rdev,
mddev);
+ rcu_read_lock();
}
}
sl = start;
@@ -1453,17 +1464,22 @@ static void raid10d(mddev_t *mddev)
sl = conf->copies;
sl--;
d = r10_bio->devs[sl].devnum;
- rdev = conf->mirrors[d].rdev;
+ rdev =
rcu_dereference(conf->mirrors[d].rdev);
if (rdev &&
test_bit(In_sync,
&rdev->flags)) {
+
atomic_inc(&rdev->nr_pending);
+ rcu_read_unlock();
if
(sync_page_io(rdev->bdev,
r10_bio->devs[sl].addr +
sect +
rdev->data_offset,
s<<9,
conf->tmppage, READ) == 0)
/* Well, this
device is dead */
md_error(mddev,
rdev);
+ rdev_dec_pending(rdev,
mddev);
+ rcu_read_lock();
}
}
+ rcu_read_unlock();
} else {
/* Cannot read from anywhere -- bye bye
array */
md_error(mddev,
conf->mirrors[r10_bio->devs[r10_bio->read_slot].devnum].rdev);
-
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