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-rw-r--r--drivers/md/md.c1
-rw-r--r--drivers/md/raid1.c115
-rw-r--r--include/linux/raid/raid1.h3
3 files changed, 109 insertions, 10 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 64e7da3..1364a1c 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -461,6 +461,7 @@ int sync_page_io(struct block_device *bdev, sector_t sector, int size,
bio_put(bio);
return ret;
}
+EXPORT_SYMBOL(sync_page_io);
static int read_disk_sb(mdk_rdev_t * rdev, int size)
{
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index c618015..b3856db 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -191,6 +191,7 @@ static void reschedule_retry(r1bio_t *r1_bio)
spin_lock_irqsave(&conf->device_lock, flags);
list_add(&r1_bio->retry_list, &conf->retry_list);
+ conf->nr_queued ++;
spin_unlock_irqrestore(&conf->device_lock, flags);
wake_up(&conf->wait_barrier);
@@ -245,9 +246,9 @@ static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int
/*
* this branch is our 'one mirror IO has finished' event handler:
*/
- if (!uptodate)
- md_error(r1_bio->mddev, conf->mirrors[mirror].rdev);
- else
+ update_head_pos(mirror, r1_bio);
+
+ if (uptodate || conf->working_disks <= 1) {
/*
* Set R1BIO_Uptodate in our master bio, so that
* we will return a good error code for to the higher
@@ -259,14 +260,8 @@ static int raid1_end_read_request(struct bio *bio, unsigned int bytes_done, int
*/
set_bit(R1BIO_Uptodate, &r1_bio->state);
- update_head_pos(mirror, r1_bio);
-
- /*
- * we have only one bio on the read side
- */
- if (uptodate)
raid_end_bio_io(r1_bio);
- else {
+ } else {
/*
* oops, read error:
*/
@@ -653,6 +648,32 @@ static void allow_barrier(conf_t *conf)
wake_up(&conf->wait_barrier);
}
+static void freeze_array(conf_t *conf)
+{
+ /* stop syncio and normal IO and wait for everything to
+ * go quite.
+ * We increment barrier and nr_waiting, and then
+ * wait until barrier+nr_pending match nr_queued+2
+ */
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier++;
+ conf->nr_waiting++;
+ wait_event_lock_irq(conf->wait_barrier,
+ conf->barrier+conf->nr_pending == conf->nr_queued+2,
+ conf->resync_lock,
+ raid1_unplug(conf->mddev->queue));
+ spin_unlock_irq(&conf->resync_lock);
+}
+static void unfreeze_array(conf_t *conf)
+{
+ /* reverse the effect of the freeze */
+ spin_lock_irq(&conf->resync_lock);
+ conf->barrier--;
+ conf->nr_waiting--;
+ wake_up(&conf->wait_barrier);
+ spin_unlock_irq(&conf->resync_lock);
+}
+
/* duplicate the data pages for behind I/O */
static struct page **alloc_behind_pages(struct bio *bio)
@@ -1196,6 +1217,7 @@ static void raid1d(mddev_t *mddev)
break;
r1_bio = list_entry(head->prev, r1bio_t, retry_list);
list_del(head->prev);
+ conf->nr_queued--;
spin_unlock_irqrestore(&conf->device_lock, flags);
mddev = r1_bio->mddev;
@@ -1235,6 +1257,74 @@ static void raid1d(mddev_t *mddev)
}
} else {
int disk;
+
+ /* we got a read error. Maybe the drive is bad. Maybe just
+ * the block and we can fix it.
+ * We freeze all other IO, and try reading the block from
+ * other devices. When we find one, we re-write
+ * and check it that fixes the read error.
+ * This is all done synchronously while the array is
+ * frozen
+ */
+ sector_t sect = r1_bio->sector;
+ int sectors = r1_bio->sectors;
+ freeze_array(conf);
+ while(sectors) {
+ int s = sectors;
+ int d = r1_bio->read_disk;
+ int success = 0;
+
+ if (s > (PAGE_SIZE>>9))
+ s = PAGE_SIZE >> 9;
+
+ do {
+ rdev = conf->mirrors[d].rdev;
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags) &&
+ sync_page_io(rdev->bdev,
+ sect + rdev->data_offset,
+ s<<9,
+ conf->tmppage, READ))
+ success = 1;
+ else {
+ d++;
+ if (d == conf->raid_disks)
+ d = 0;
+ }
+ } while (!success && d != r1_bio->read_disk);
+
+ if (success) {
+ /* write it back and re-read */
+ while (d != r1_bio->read_disk) {
+ if (d==0)
+ d = conf->raid_disks;
+ d--;
+ rdev = conf->mirrors[d].rdev;
+ if (rdev &&
+ test_bit(In_sync, &rdev->flags)) {
+ if (sync_page_io(rdev->bdev,
+ sect + rdev->data_offset,
+ s<<9, conf->tmppage, WRITE) == 0 ||
+ sync_page_io(rdev->bdev,
+ sect + rdev->data_offset,
+ s<<9, conf->tmppage, READ) == 0) {
+ /* Well, this device is dead */
+ md_error(mddev, rdev);
+ }
+ }
+ }
+ } else {
+ /* Cannot read from anywhere -- bye bye array */
+ md_error(mddev, conf->mirrors[r1_bio->read_disk].rdev);
+ break;
+ }
+ sectors -= s;
+ sect += s;
+ }
+
+
+ unfreeze_array(conf);
+
bio = r1_bio->bios[r1_bio->read_disk];
if ((disk=read_balance(conf, r1_bio)) == -1) {
printk(KERN_ALERT "raid1: %s: unrecoverable I/O"
@@ -1529,6 +1619,10 @@ static int run(mddev_t *mddev)
memset(conf->mirrors, 0, sizeof(struct mirror_info)*mddev->raid_disks);
+ conf->tmppage = alloc_page(GFP_KERNEL);
+ if (!conf->tmppage)
+ goto out_no_mem;
+
conf->poolinfo = kmalloc(sizeof(*conf->poolinfo), GFP_KERNEL);
if (!conf->poolinfo)
goto out_no_mem;
@@ -1635,6 +1729,7 @@ out_free_conf:
if (conf->r1bio_pool)
mempool_destroy(conf->r1bio_pool);
kfree(conf->mirrors);
+ __free_page(conf->tmppage);
kfree(conf->poolinfo);
kfree(conf);
mddev->private = NULL;
diff --git a/include/linux/raid/raid1.h b/include/linux/raid/raid1.h
index c556742..cbe4238 100644
--- a/include/linux/raid/raid1.h
+++ b/include/linux/raid/raid1.h
@@ -46,6 +46,7 @@ struct r1_private_data_s {
spinlock_t resync_lock;
int nr_pending;
int nr_waiting;
+ int nr_queued;
int barrier;
sector_t next_resync;
int fullsync; /* set to 1 if a full sync is needed,
@@ -57,6 +58,8 @@ struct r1_private_data_s {
struct pool_info *poolinfo;
+ struct page *tmppage;
+
mempool_t *r1bio_pool;
mempool_t *r1buf_pool;
};
generated by cgit v1.1 at 2024-12-27 07:18:08 +0000