Btrfs: refactor caching_thread()
We're also going to load the free space tree from caching_thread(), so
we should refactor some of the common code.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 42c41dc..60df67e 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1262,6 +1262,9 @@
atomic_t count;
};
+/* Once caching_thread() finds this much free space, it will wake up waiters. */
+#define CACHING_CTL_WAKE_UP (1024 * 1024 * 2)
+
struct btrfs_io_ctl {
void *cur, *orig;
struct page *page;
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 601d7d4..af8ffb5 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -375,11 +375,10 @@
return total_added;
}
-static noinline void caching_thread(struct btrfs_work *work)
+static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl)
{
struct btrfs_block_group_cache *block_group;
struct btrfs_fs_info *fs_info;
- struct btrfs_caching_control *caching_ctl;
struct btrfs_root *extent_root;
struct btrfs_path *path;
struct extent_buffer *leaf;
@@ -387,16 +386,15 @@
u64 total_found = 0;
u64 last = 0;
u32 nritems;
- int ret = -ENOMEM;
+ int ret;
- caching_ctl = container_of(work, struct btrfs_caching_control, work);
block_group = caching_ctl->block_group;
fs_info = block_group->fs_info;
extent_root = fs_info->extent_root;
path = btrfs_alloc_path();
if (!path)
- goto out;
+ return -ENOMEM;
last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET);
@@ -413,15 +411,11 @@
key.objectid = last;
key.offset = 0;
key.type = BTRFS_EXTENT_ITEM_KEY;
-again:
- mutex_lock(&caching_ctl->mutex);
- /* need to make sure the commit_root doesn't disappear */
- down_read(&fs_info->commit_root_sem);
next:
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
- goto err;
+ goto out;
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
@@ -446,12 +440,14 @@
up_read(&fs_info->commit_root_sem);
mutex_unlock(&caching_ctl->mutex);
cond_resched();
- goto again;
+ mutex_lock(&caching_ctl->mutex);
+ down_read(&fs_info->commit_root_sem);
+ goto next;
}
ret = btrfs_next_leaf(extent_root, path);
if (ret < 0)
- goto err;
+ goto out;
if (ret)
break;
leaf = path->nodes[0];
@@ -489,7 +485,7 @@
else
last = key.objectid + key.offset;
- if (total_found > (1024 * 1024 * 2)) {
+ if (total_found > CACHING_CTL_WAKE_UP) {
total_found = 0;
wake_up(&caching_ctl->wait);
}
@@ -503,25 +499,36 @@
block_group->key.offset);
caching_ctl->progress = (u64)-1;
+out:
+ btrfs_free_path(path);
+ return ret;
+}
+
+static noinline void caching_thread(struct btrfs_work *work)
+{
+ struct btrfs_block_group_cache *block_group;
+ struct btrfs_fs_info *fs_info;
+ struct btrfs_caching_control *caching_ctl;
+ int ret;
+
+ caching_ctl = container_of(work, struct btrfs_caching_control, work);
+ block_group = caching_ctl->block_group;
+ fs_info = block_group->fs_info;
+
+ mutex_lock(&caching_ctl->mutex);
+ down_read(&fs_info->commit_root_sem);
+
+ ret = load_extent_tree_free(caching_ctl);
+
spin_lock(&block_group->lock);
block_group->caching_ctl = NULL;
- block_group->cached = BTRFS_CACHE_FINISHED;
+ block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED;
spin_unlock(&block_group->lock);
-err:
- btrfs_free_path(path);
up_read(&fs_info->commit_root_sem);
-
- free_excluded_extents(extent_root, block_group);
-
+ free_excluded_extents(fs_info->extent_root, block_group);
mutex_unlock(&caching_ctl->mutex);
-out:
- if (ret) {
- spin_lock(&block_group->lock);
- block_group->caching_ctl = NULL;
- block_group->cached = BTRFS_CACHE_ERROR;
- spin_unlock(&block_group->lock);
- }
+
wake_up(&caching_ctl->wait);
put_caching_control(caching_ctl);