Btrfs: Deal with failed writes in mirrored configurations
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9a72411..57ab755 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1425,6 +1425,7 @@
int stripe_index;
int i;
int num_stripes;
+ int max_errors = 0;
struct btrfs_multi_bio *multi = NULL;
if (multi_ret && !(rw & (1 << BIO_RW))) {
@@ -1436,6 +1437,8 @@
GFP_NOFS);
if (!multi)
return -ENOMEM;
+
+ atomic_set(&multi->error, 0);
}
spin_lock(&em_tree->lock);
@@ -1462,8 +1465,10 @@
if (map->type & (BTRFS_BLOCK_GROUP_RAID1 |
BTRFS_BLOCK_GROUP_DUP)) {
stripes_required = map->num_stripes;
+ max_errors = 1;
} else if (map->type & BTRFS_BLOCK_GROUP_RAID10) {
stripes_required = map->sub_stripes;
+ max_errors = 1;
}
}
if (multi_ret && rw == WRITE &&
@@ -1561,6 +1566,7 @@
if (multi_ret) {
*multi_ret = multi;
multi->num_stripes = num_stripes;
+ multi->max_errors = max_errors;
}
out:
free_extent_map(em);
@@ -1598,14 +1604,19 @@
return 1;
#endif
if (err)
- multi->error = err;
+ atomic_inc(&multi->error);
if (atomic_dec_and_test(&multi->stripes_pending)) {
bio->bi_private = multi->private;
bio->bi_end_io = multi->end_io;
- if (!err && multi->error)
- err = multi->error;
+ /* only send an error to the higher layers if it is
+ * beyond the tolerance of the multi-bio
+ */
+ if (atomic_read(&multi->error) > multi->max_errors)
+ err = -EIO;
+ else
+ err = 0;
kfree(multi);
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)