Btrfs: Dynamic chunk and block group allocation
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 90a8d45..a52a13f 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -131,7 +131,7 @@
btrfs_release_path(root, path);
BUG_ON(*start < search_start);
- if (*start + num_bytes >= search_end) {
+ if (*start + num_bytes > search_end) {
ret = -ENOSPC;
goto error;
}
@@ -159,8 +159,9 @@
return -ENOMEM;
ret = find_free_dev_extent(trans, device, path, num_bytes, start);
- if (ret)
+ if (ret) {
goto err;
+ }
key.objectid = device->devid;
key.offset = *start;
@@ -214,22 +215,6 @@
return ret;
}
-static struct btrfs_device *next_device(struct list_head *head,
- struct list_head *last)
-{
- struct list_head *next = last->next;
- struct btrfs_device *dev;
-
- if (list_empty(head))
- return NULL;
-
- if (next == head)
- next = next->next;
-
- dev = list_entry(next, struct btrfs_device, dev_list);
- return dev;
-}
-
static int find_next_devid(struct btrfs_root *root, struct btrfs_path *path,
u64 *objectid)
{
@@ -397,31 +382,63 @@
int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
struct btrfs_root *extent_root, u64 *start,
- u64 *num_bytes, u32 type)
+ u64 *num_bytes, u64 type)
{
u64 dev_offset;
struct btrfs_root *chunk_root = extent_root->fs_info->chunk_root;
struct btrfs_stripe *stripes;
struct btrfs_device *device = NULL;
struct btrfs_chunk *chunk;
+ struct list_head private_devs;
struct list_head *dev_list = &extent_root->fs_info->devices;
- struct list_head *last_dev = extent_root->fs_info->last_device;
+ struct list_head *cur;
struct extent_map_tree *em_tree;
struct map_lookup *map;
struct extent_map *em;
u64 physical;
u64 calc_size = 1024 * 1024 * 1024;
- int num_stripes;
+ u64 avail;
+ u64 max_avail = 0;
+ int num_stripes = 1;
+ int looped = 0;
int ret;
- int index = 0;
+ int index;
struct btrfs_key key;
+ if (list_empty(dev_list))
+ return -ENOSPC;
+again:
+ INIT_LIST_HEAD(&private_devs);
+ cur = dev_list->next;
+ index = 0;
+ /* build a private list of devices we will allocate from */
+ while(index < num_stripes) {
+ device = list_entry(cur, struct btrfs_device, dev_list);
+ avail = device->total_bytes - device->bytes_used;
+ cur = cur->next;
+ if (avail > max_avail)
+ max_avail = avail;
+ if (avail >= calc_size) {
+ list_move_tail(&device->dev_list, &private_devs);
+ index++;
+ }
+ if (cur == dev_list)
+ break;
+ }
+ if (index < num_stripes) {
+ list_splice(&private_devs, dev_list);
+ if (!looped && max_avail > 0) {
+ looped = 1;
+ calc_size = max_avail;
+ goto again;
+ }
+ return -ENOSPC;
+ }
ret = find_next_chunk(chunk_root, &key.objectid);
if (ret)
return ret;
- num_stripes = 1;
chunk = kmalloc(btrfs_chunk_item_size(num_stripes), GFP_NOFS);
if (!chunk)
return -ENOMEM;
@@ -429,11 +446,12 @@
stripes = &chunk->stripe;
*num_bytes = calc_size;
+ index = 0;
while(index < num_stripes) {
- device = next_device(dev_list, last_dev);
- BUG_ON(!device);
- last_dev = &device->dev_list;
- extent_root->fs_info->last_device = last_dev;
+ BUG_ON(list_empty(&private_devs));
+ cur = private_devs.next;
+ device = list_entry(cur, struct btrfs_device, dev_list);
+ list_move_tail(&device->dev_list, dev_list);
ret = btrfs_alloc_dev_extent(trans, device,
key.objectid,
@@ -449,6 +467,7 @@
physical = dev_offset;
index++;
}
+ BUG_ON(!list_empty(&private_devs));
/* key.objectid was set above */
key.offset = *num_bytes;
@@ -692,17 +711,17 @@
int ret;
devid = btrfs_device_id(leaf, dev_item);
- if (btrfs_find_device(root, devid))
- return 0;
-
- device = kmalloc(sizeof(*device), GFP_NOFS);
- if (!device)
- return -ENOMEM;
+ device = btrfs_find_device(root, devid);
+ if (!device) {
+ device = kmalloc(sizeof(*device), GFP_NOFS);
+ if (!device)
+ return -ENOMEM;
+ list_add(&device->dev_list, &root->fs_info->devices);
+ }
fill_device_from_item(leaf, dev_item, device);
device->dev_root = root->fs_info->dev_root;
device->bdev = root->fs_info->sb->s_bdev;
- list_add(&device->dev_list, &root->fs_info->devices);
memcpy(&device->dev_key, key, sizeof(*key));
ret = 0;
#if 0