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-rw-r--r--drivers/md/raid1.c153
1 files changed, 115 insertions, 38 deletions
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 4d40d9d54a2..3214606204d 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -764,7 +764,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
mirror_info_t *mirror;
r1bio_t *r1_bio;
struct bio *read_bio;
- int i, targets = 0, disks;
+ int i, disks;
struct bitmap *bitmap;
unsigned long flags;
const int rw = bio_data_dir(bio);
@@ -772,6 +772,9 @@ static int make_request(mddev_t *mddev, struct bio * bio)
const unsigned long do_flush_fua = (bio->bi_rw & (REQ_FLUSH | REQ_FUA));
mdk_rdev_t *blocked_rdev;
int plugged;
+ int first_clone;
+ int sectors_handled;
+ int max_sectors;
/*
* Register the new request and wait if the reconstruction
@@ -832,7 +835,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
/*
* read balancing logic:
*/
- int max_sectors;
int rdisk;
read_again:
@@ -872,7 +874,6 @@ read_again:
/* could not read all from this device, so we will
* need another r1_bio.
*/
- int sectors_handled;
sectors_handled = (r1_bio->sector + max_sectors
- bio->bi_sector);
@@ -906,9 +907,15 @@ read_again:
/*
* WRITE:
*/
- /* first select target devices under spinlock and
+ /* first select target devices under rcu_lock and
* inc refcount on their rdev. Record them by setting
* bios[x] to bio
+ * If there are known/acknowledged bad blocks on any device on
+ * which we have seen a write error, we want to avoid writing those
+ * blocks.
+ * This potentially requires several writes to write around
+ * the bad blocks. Each set of writes gets it's own r1bio
+ * with a set of bios attached.
*/
plugged = mddev_check_plugged(mddev);
@@ -916,6 +923,7 @@ read_again:
retry_write:
blocked_rdev = NULL;
rcu_read_lock();
+ max_sectors = r1_bio->sectors;
for (i = 0; i < disks; i++) {
mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
if (rdev && unlikely(test_bit(Blocked, &rdev->flags))) {
@@ -923,17 +931,56 @@ read_again:
blocked_rdev = rdev;
break;
}
- if (rdev && !test_bit(Faulty, &rdev->flags)) {
- atomic_inc(&rdev->nr_pending);
- if (test_bit(Faulty, &rdev->flags)) {
+ r1_bio->bios[i] = NULL;
+ if (!rdev || test_bit(Faulty, &rdev->flags)) {
+ set_bit(R1BIO_Degraded, &r1_bio->state);
+ continue;
+ }
+
+ atomic_inc(&rdev->nr_pending);
+ if (test_bit(WriteErrorSeen, &rdev->flags)) {
+ sector_t first_bad;
+ int bad_sectors;
+ int is_bad;
+
+ is_bad = is_badblock(rdev, r1_bio->sector,
+ max_sectors,
+ &first_bad, &bad_sectors);
+ if (is_bad < 0) {
+ /* mustn't write here until the bad block is
+ * acknowledged*/
+ set_bit(BlockedBadBlocks, &rdev->flags);
+ blocked_rdev = rdev;
+ break;
+ }
+ if (is_bad && first_bad <= r1_bio->sector) {
+ /* Cannot write here at all */
+ bad_sectors -= (r1_bio->sector - first_bad);
+ if (bad_sectors < max_sectors)
+ /* mustn't write more than bad_sectors
+ * to other devices yet
+ */
+ max_sectors = bad_sectors;
rdev_dec_pending(rdev, mddev);
- r1_bio->bios[i] = NULL;
- } else {
- r1_bio->bios[i] = bio;
- targets++;
+ /* We don't set R1BIO_Degraded as that
+ * only applies if the disk is
+ * missing, so it might be re-added,
+ * and we want to know to recover this
+ * chunk.
+ * In this case the device is here,
+ * and the fact that this chunk is not
+ * in-sync is recorded in the bad
+ * block log
+ */
+ continue;
}
- } else
- r1_bio->bios[i] = NULL;
+ if (is_bad) {
+ int good_sectors = first_bad - r1_bio->sector;
+ if (good_sectors < max_sectors)
+ max_sectors = good_sectors;
+ }
+ }
+ r1_bio->bios[i] = bio;
}
rcu_read_unlock();
@@ -944,48 +991,56 @@ read_again:
for (j = 0; j < i; j++)
if (r1_bio->bios[j])
rdev_dec_pending(conf->mirrors[j].rdev, mddev);
-
+ r1_bio->state = 0;
allow_barrier(conf);
md_wait_for_blocked_rdev(blocked_rdev, mddev);
wait_barrier(conf);
goto retry_write;
}
- if (targets < conf->raid_disks) {
- /* array is degraded, we will not clear the bitmap
- * on I/O completion (see raid1_end_write_request) */
- set_bit(R1BIO_Degraded, &r1_bio->state);
+ if (max_sectors < r1_bio->sectors) {
+ /* We are splitting this write into multiple parts, so
+ * we need to prepare for allocating another r1_bio.
+ */
+ r1_bio->sectors = max_sectors;
+ spin_lock_irq(&conf->device_lock);
+ if (bio->bi_phys_segments == 0)
+ bio->bi_phys_segments = 2;
+ else
+ bio->bi_phys_segments++;
+ spin_unlock_irq(&conf->device_lock);
}
-
- /* do behind I/O ?
- * Not if there are too many, or cannot allocate memory,
- * or a reader on WriteMostly is waiting for behind writes
- * to flush */
- if (bitmap &&
- (atomic_read(&bitmap->behind_writes)
- < mddev->bitmap_info.max_write_behind) &&
- !waitqueue_active(&bitmap->behind_wait))
- alloc_behind_pages(bio, r1_bio);
+ sectors_handled = r1_bio->sector + max_sectors - bio->bi_sector;
atomic_set(&r1_bio->remaining, 1);
atomic_set(&r1_bio->behind_remaining, 0);
- bitmap_startwrite(bitmap, bio->bi_sector, r1_bio->sectors,
- test_bit(R1BIO_BehindIO, &r1_bio->state));
+ first_clone = 1;
for (i = 0; i < disks; i++) {
struct bio *mbio;
if (!r1_bio->bios[i])
continue;
mbio = bio_clone_mddev(bio, GFP_NOIO, mddev);
- r1_bio->bios[i] = mbio;
-
- mbio->bi_sector = r1_bio->sector + conf->mirrors[i].rdev->data_offset;
- mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
- mbio->bi_end_io = raid1_end_write_request;
- mbio->bi_rw = WRITE | do_flush_fua | do_sync;
- mbio->bi_private = r1_bio;
-
+ md_trim_bio(mbio, r1_bio->sector - bio->bi_sector, max_sectors);
+
+ if (first_clone) {
+ /* do behind I/O ?
+ * Not if there are too many, or cannot
+ * allocate memory, or a reader on WriteMostly
+ * is waiting for behind writes to flush */
+ if (bitmap &&
+ (atomic_read(&bitmap->behind_writes)
+ < mddev->bitmap_info.max_write_behind) &&
+ !waitqueue_active(&bitmap->behind_wait))
+ alloc_behind_pages(mbio, r1_bio);
+
+ bitmap_startwrite(bitmap, r1_bio->sector,
+ r1_bio->sectors,
+ test_bit(R1BIO_BehindIO,
+ &r1_bio->state));
+ first_clone = 0;
+ }
if (r1_bio->behind_pages) {
struct bio_vec *bvec;
int j;
@@ -1003,6 +1058,15 @@ read_again:
atomic_inc(&r1_bio->behind_remaining);
}
+ r1_bio->bios[i] = mbio;
+
+ mbio->bi_sector = (r1_bio->sector +
+ conf->mirrors[i].rdev->data_offset);
+ mbio->bi_bdev = conf->mirrors[i].rdev->bdev;
+ mbio->bi_end_io = raid1_end_write_request;
+ mbio->bi_rw = WRITE | do_flush_fua | do_sync;
+ mbio->bi_private = r1_bio;
+
atomic_inc(&r1_bio->remaining);
spin_lock_irqsave(&conf->device_lock, flags);
bio_list_add(&conf->pending_bio_list, mbio);
@@ -1013,6 +1077,19 @@ read_again:
/* In case raid1d snuck in to freeze_array */
wake_up(&conf->wait_barrier);
+ if (sectors_handled < (bio->bi_size >> 9)) {
+ /* We need another r1_bio. It has already been counted
+ * in bio->bi_phys_segments
+ */
+ r1_bio = mempool_alloc(conf->r1bio_pool, GFP_NOIO);
+ r1_bio->master_bio = bio;
+ r1_bio->sectors = (bio->bi_size >> 9) - sectors_handled;
+ r1_bio->state = 0;
+ r1_bio->mddev = mddev;
+ r1_bio->sector = bio->bi_sector + sectors_handled;
+ goto retry_write;
+ }
+
if (do_sync || !bitmap || !plugged)
md_wakeup_thread(mddev->thread);