Hot replace / auto replace is important volume manager feature
and is critical to the data center operations, so that the degraded
volume can be brought back to a healthy state at the earliest and
without manual intervention.
This modifies the existing replace code to suite the need of auto
replace, in the long run I hope both the codes to be merged.
Signed-off-by: Anand Jain <anand.j...@oracle.com>
---
fs/btrfs/dev-replace.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++++
fs/btrfs/dev-replace.h | 1 +
2 files changed, 117 insertions(+)
diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 02df419..3294b33 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -914,3 +914,119 @@ void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info
*fs_info)
&fs_info->fs_state));
}
}
+
+int btrfs_dev_replace_start_v2(struct btrfs_root *root, char *tgt_path,
+ struct btrfs_device *src_device)
+{
+ struct btrfs_trans_handle *trans;
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_dev_replace *dev_replace = &fs_info->dev_replace;
+ int ret;
+ struct btrfs_device *tgt_device = NULL;
+
+ /*
+ * proceure here is the same as in the replace triggered from the
+ * user land, some day we could merg this with it
+ */
+ WARN_ON(!src_device);
+ mutex_lock(&fs_info->volume_mutex);
+ ret = btrfs_init_dev_replace_tgtdev(root, tgt_path,
+ src_device, &tgt_device);
+ mutex_unlock(&fs_info->volume_mutex);
+ if (ret)
+ return ret;
+ WARN_ON(!tgt_device);
+
+ trans = btrfs_attach_transaction(root);
+ if (!IS_ERR(trans)) {
+ ret = btrfs_commit_transaction(trans, root);
+ if (ret)
+ return ret;
+ } else if (PTR_ERR(trans) != -ENOENT) {
+ return PTR_ERR(trans);
+ }
+
+ btrfs_dev_replace_lock(dev_replace);
+ if (dev_replace->replace_state ==
+ BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED ||
+ dev_replace->replace_state ==
+ BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED)
+ goto leave;
+
+ dev_replace->cont_reading_from_srcdev_mode =
+ BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_AVOID;
+ dev_replace->srcdev = src_device;
+ dev_replace->tgtdev = tgt_device;
+
+ dev_replace->replace_state = BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED;
+ dev_replace->time_started = get_seconds();
+ dev_replace->cursor_left = 0;
+ dev_replace->committed_cursor_left = 0;
+ dev_replace->cursor_left_last_write_of_item = 0;
+ dev_replace->cursor_right = 0;
+ dev_replace->is_valid = 1;
+ dev_replace->item_needs_writeback = 1;
+
+ printk_in_rcu(KERN_INFO
+ "BTRFS: auto replace from %s (devid %llu) to %s started\n",
+ rcu_str_deref(src_device->name),
+ src_device->devid,
+ rcu_str_deref(tgt_device->name));
+
+ btrfs_dev_replace_unlock(dev_replace);
+
+ ret = btrfs_sysfs_add_device_link(tgt_device->fs_devices, tgt_device,
0);
+ if (ret)
+ btrfs_err(fs_info, "kobj add dev failed %d\n", ret);
+
+ btrfs_wait_ordered_roots(fs_info, -1);
+
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ btrfs_dev_replace_lock(dev_replace);
+ goto leave;
+ }
+ ret = btrfs_commit_transaction(trans, root);
+ WARN_ON(ret);
+
+ ret = btrfs_scrub_dev(fs_info, src_device->devid, 0,
+ btrfs_device_get_total_bytes(src_device),
+ &dev_replace->scrub_progress, 0, 1);
+
+ ret = btrfs_dev_replace_finishing(fs_info, ret);
+ if (ret == -EINPROGRESS)
+ ret = 0;
+ else
+ WARN_ON(ret);
+
+ return ret;
+
+leave:
+ dev_replace->srcdev = NULL;
+ dev_replace->tgtdev = NULL;
+ btrfs_dev_replace_unlock(dev_replace);
+ btrfs_destroy_dev_replace_tgtdev(fs_info, tgt_device);
+ return ret;
+}
+
+int btrfs_auto_replace_start(struct btrfs_root *root,
+ struct btrfs_device *src_device)
+{
+ char *tgt_path;
+ int ret;
+
+ if (btrfs_get_spare_device(&tgt_path)) {
+ btrfs_err(root->fs_info,
+ "No spare device found/configured in the kernel");
+ return -EINVAL;
+ }
+
+ ret = btrfs_dev_replace_start_v2(root, tgt_path, src_device);
+ if (ret)
+ btrfs_put_spare_device(tgt_path);
+
+ kfree(tgt_path);
+
+ return 0;
+}
diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h
index 20035cb..2ead9a6 100644
--- a/fs/btrfs/dev-replace.h
+++ b/fs/btrfs/dev-replace.h
@@ -41,4 +41,5 @@ static inline void btrfs_dev_replace_stats_inc(atomic64_t
*stat_value)
{
atomic64_inc(stat_value);
}
+int btrfs_auto_replace_start(struct btrfs_root *root, struct btrfs_device
*src_device);
#endif
--
2.4.1
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