Btrfs: Add a special device list for chunk allocations
This allows other code that needs to walk every device in the FS to do so
without locking against allocations.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 107fc74..5619e50 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -111,6 +111,7 @@
if (!fs_devices)
return -ENOMEM;
INIT_LIST_HEAD(&fs_devices->devices);
+ INIT_LIST_HEAD(&fs_devices->alloc_list);
list_add(&fs_devices->list, &fs_uuids);
memcpy(fs_devices->fsid, disk_super->fsid, BTRFS_FSID_SIZE);
fs_devices->latest_devid = devid;
@@ -139,6 +140,7 @@
return -ENOMEM;
}
list_add(&device->dev_list, &fs_devices->devices);
+ list_add(&device->dev_alloc_list, &fs_devices->alloc_list);
fs_devices->num_devices++;
}
@@ -660,7 +662,7 @@
struct btrfs_device *device = NULL;
struct btrfs_chunk *chunk;
struct list_head private_devs;
- struct list_head *dev_list = &extent_root->fs_info->fs_devices->devices;
+ struct list_head *dev_list;
struct list_head *cur;
struct extent_map_tree *em_tree;
struct map_lookup *map;
@@ -682,6 +684,7 @@
int stripe_len = 64 * 1024;
struct btrfs_key key;
+ dev_list = &extent_root->fs_info->fs_devices->alloc_list;
if (list_empty(dev_list))
return -ENOSPC;
@@ -752,12 +755,12 @@
/* build a private list of devices we will allocate from */
while(index < num_stripes) {
- device = list_entry(cur, struct btrfs_device, dev_list);
+ device = list_entry(cur, struct btrfs_device, dev_alloc_list);
avail = device->total_bytes - device->bytes_used;
cur = cur->next;
if (avail >= min_free) {
- list_move_tail(&device->dev_list, &private_devs);
+ list_move_tail(&device->dev_alloc_list, &private_devs);
index++;
if (type & BTRFS_BLOCK_GROUP_DUP)
index++;
@@ -812,12 +815,12 @@
struct btrfs_stripe *stripe;
BUG_ON(list_empty(&private_devs));
cur = private_devs.next;
- device = list_entry(cur, struct btrfs_device, dev_list);
+ device = list_entry(cur, struct btrfs_device, dev_alloc_list);
/* loop over this device again if we're doing a dup group */
if (!(type & BTRFS_BLOCK_GROUP_DUP) ||
(index == num_stripes - 1))
- list_move_tail(&device->dev_list, dev_list);
+ list_move_tail(&device->dev_alloc_list, dev_list);
ret = btrfs_alloc_dev_extent(trans, device,
info->chunk_root->root_key.objectid,
@@ -1329,6 +1332,8 @@
return -ENOMEM;
list_add(&device->dev_list,
&root->fs_info->fs_devices->devices);
+ list_add(&device->dev_alloc_list,
+ &root->fs_info->fs_devices->alloc_list);
device->barriers = 1;
spin_lock_init(&device->io_lock);
}