Btrfs: disallow some operations on the device replace target device
This patch adds some code to disallow operations on the device that
is used as the target for the device replace operation.
Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 33ca36b..31f7af8 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -518,8 +518,9 @@
/* This is the initialized path, it is safe to release the devices. */
list_for_each_entry_safe(device, next, &fs_devices->devices, dev_list) {
if (device->in_fs_metadata) {
- if (!latest_transid ||
- device->generation > latest_transid) {
+ if (!device->is_tgtdev_for_dev_replace &&
+ (!latest_transid ||
+ device->generation > latest_transid)) {
latest_devid = device->devid;
latest_transid = device->generation;
latest_bdev = device->bdev;
@@ -814,7 +815,7 @@
*length = 0;
- if (start >= device->total_bytes)
+ if (start >= device->total_bytes || device->is_tgtdev_for_dev_replace)
return 0;
path = btrfs_alloc_path();
@@ -931,7 +932,7 @@
max_hole_size = 0;
hole_size = 0;
- if (search_start >= search_end) {
+ if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
ret = -ENOSPC;
goto error;
}
@@ -1114,6 +1115,7 @@
struct btrfs_key key;
WARN_ON(!device->in_fs_metadata);
+ WARN_ON(device->is_tgtdev_for_dev_replace);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
@@ -1375,7 +1377,9 @@
* is held.
*/
list_for_each_entry(tmp, devices, dev_list) {
- if (tmp->in_fs_metadata && !tmp->bdev) {
+ if (tmp->in_fs_metadata &&
+ !tmp->is_tgtdev_for_dev_replace &&
+ !tmp->bdev) {
device = tmp;
break;
}
@@ -1406,6 +1410,12 @@
}
}
+ if (device->is_tgtdev_for_dev_replace) {
+ pr_err("btrfs: unable to remove the dev_replace target dev\n");
+ ret = -EINVAL;
+ goto error_brelse;
+ }
+
if (device->writeable && root->fs_info->fs_devices->rw_devices == 1) {
printk(KERN_ERR "btrfs: unable to remove the only writeable "
"device\n");
@@ -1425,6 +1435,11 @@
if (ret)
goto error_undo;
+ /*
+ * TODO: the superblock still includes this device in its num_devices
+ * counter although write_all_supers() is not locked out. This
+ * could give a filesystem state which requires a degraded mount.
+ */
ret = btrfs_rm_dev_item(root->fs_info->chunk_root, device);
if (ret)
goto error_undo;
@@ -1808,6 +1823,7 @@
device->dev_root = root->fs_info->dev_root;
device->bdev = bdev;
device->in_fs_metadata = 1;
+ device->is_tgtdev_for_dev_replace = 0;
device->mode = FMODE_EXCL;
set_blocksize(device->bdev, 4096);
@@ -1971,7 +1987,8 @@
if (!device->writeable)
return -EACCES;
- if (new_size <= device->total_bytes)
+ if (new_size <= device->total_bytes ||
+ device->is_tgtdev_for_dev_replace)
return -EINVAL;
btrfs_set_super_total_bytes(super_copy, old_total + diff);
@@ -2600,7 +2617,8 @@
size_to_free = div_factor(old_size, 1);
size_to_free = min(size_to_free, (u64)1 * 1024 * 1024);
if (!device->writeable ||
- device->total_bytes - device->bytes_used > size_to_free)
+ device->total_bytes - device->bytes_used > size_to_free ||
+ device->is_tgtdev_for_dev_replace)
continue;
ret = btrfs_shrink_device(device, old_size - size_to_free);
@@ -3132,6 +3150,9 @@
u64 old_size = device->total_bytes;
u64 diff = device->total_bytes - new_size;
+ if (device->is_tgtdev_for_dev_replace)
+ return -EINVAL;
+
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
@@ -3401,7 +3422,8 @@
continue;
}
- if (!device->in_fs_metadata)
+ if (!device->in_fs_metadata ||
+ device->is_tgtdev_for_dev_replace)
continue;
if (device->total_bytes > device->bytes_used)
@@ -4612,6 +4634,7 @@
device->io_align = btrfs_device_io_align(leaf, dev_item);
device->io_width = btrfs_device_io_width(leaf, dev_item);
device->sector_size = btrfs_device_sector_size(leaf, dev_item);
+ device->is_tgtdev_for_dev_replace = 0;
ptr = (unsigned long)btrfs_device_uuid(dev_item);
read_extent_buffer(leaf, device->uuid, ptr, BTRFS_UUID_SIZE);
@@ -4722,7 +4745,7 @@
fill_device_from_item(leaf, dev_item, device);
device->dev_root = root->fs_info->dev_root;
device->in_fs_metadata = 1;
- if (device->writeable) {
+ if (device->writeable && !device->is_tgtdev_for_dev_replace) {
device->fs_devices->total_rw_bytes += device->total_bytes;
spin_lock(&root->fs_info->free_chunk_lock);
root->fs_info->free_chunk_space += device->total_bytes -
