[dm-devel] [PATCH] DM data integrity support
Martin K. Petersen
martin.petersen at oracle.com
Fri Oct 17 14:47:00 UTC 2008
Add support for data integrity to DM.
If all subdevices support the same protection format the DM device is
flagged as capable.
Signed-off-by: Martin K. Petersen <martin.petersen at oracle.com>
---
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -874,7 +874,43 @@ void dm_table_set_restrictions(struct dm
queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q);
else
queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q);
+}
+void dm_table_set_integrity(struct dm_table *t, struct mapped_device *md)
+{
+ struct list_head *devices = dm_table_get_devices(t);
+ struct dm_dev_internal *prev, *cur;
+
+ /*
+ * Run through all devices to ensure they have matching
+ * integrity profile
+ */
+ cur = prev = NULL;
+
+ list_for_each_entry(cur, devices, list) {
+
+ if (prev &&
+ blk_integrity_compare(prev->dm_dev.bdev->bd_disk,
+ cur->dm_dev.bdev->bd_disk) < 0) {
+ printk(KERN_ERR "%s: %s %s integrity mismatch!\n",
+ __func__, prev->dm_dev.bdev->bd_disk->disk_name,
+ cur->dm_dev.bdev->bd_disk->disk_name);
+ return;
+ }
+ prev = cur;
+ }
+
+ if (!prev || !bdev_get_integrity(prev->dm_dev.bdev))
+ return;
+
+ /* Register dm device as being integrity capable */
+ if (blk_integrity_register(dm_disk(md),
+ bdev_get_integrity(prev->dm_dev.bdev)))
+ printk(KERN_ERR "%s: %s Could not register integrity!\n",
+ __func__, dm_disk(md)->disk_name);
+ else
+ printk(KERN_INFO "Enabling data integrity on %s\n",
+ dm_disk(md)->disk_name);
}
unsigned int dm_table_get_num_targets(struct dm_table *t)
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -669,6 +669,13 @@ static struct bio *split_bvec(struct bio
clone->bi_size = to_bytes(len);
clone->bi_io_vec->bv_offset = offset;
clone->bi_io_vec->bv_len = clone->bi_size;
+ clone->bi_flags |= 1 << BIO_CLONED;
+
+ if (bio_integrity(bio)) {
+ bio_integrity_clone(clone, bio, bs);
+ bio_integrity_trim(clone,
+ bio_sector_offset(bio, idx, offset), len);
+ }
return clone;
}
@@ -690,6 +697,14 @@ static struct bio *clone_bio(struct bio
clone->bi_vcnt = idx + bv_count;
clone->bi_size = to_bytes(len);
clone->bi_flags &= ~(1 << BIO_SEG_VALID);
+
+ if (bio_integrity(bio)) {
+ bio_integrity_clone(clone, bio, bs);
+
+ if (idx != bio->bi_idx || clone->bi_size < bio->bi_size)
+ bio_integrity_trim(clone,
+ bio_sector_offset(bio, idx, 0), len);
+ }
return clone;
}
@@ -1161,6 +1176,7 @@ static void free_dev(struct mapped_devic
mempool_destroy(md->tio_pool);
mempool_destroy(md->io_pool);
bioset_free(md->bs);
+ blk_integrity_unregister(md->disk);
del_gendisk(md->disk);
free_minor(minor);
@@ -1226,6 +1242,7 @@ static int __bind(struct mapped_device *
write_lock(&md->map_lock);
md->map = t;
dm_table_set_restrictions(t, q);
+ dm_table_set_integrity(t, md);
write_unlock(&md->map_lock);
return 0;
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -41,6 +41,7 @@ struct dm_target *dm_table_get_target(st
struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index);
struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector);
void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q);
+void dm_table_set_integrity(struct dm_table *t, struct mapped_device *md);
struct list_head *dm_table_get_devices(struct dm_table *t);
void dm_table_presuspend_targets(struct dm_table *t);
void dm_table_postsuspend_targets(struct dm_table *t);
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