Btrfs: add btrfs_trim_fs() to handle FITRIM
We take an free extent out from allocator, trim it, then put it back,
but before we trim the block group, we should make sure the block group is
cached, so plus a little change to make cache_block_group() run without a
transaction.
Signed-off-by: Li Dongyang <lidongyang@novell.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index e990d2d..1efeda3 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -440,7 +440,7 @@
* allocate blocks for the tree root we can't do the fast caching since
* we likely hold important locks.
*/
- if (!trans->transaction->in_commit &&
+ if (trans && (!trans->transaction->in_commit) &&
(root && root != root->fs_info->tree_root)) {
spin_lock(&cache->lock);
if (cache->cached != BTRFS_CACHE_NO) {
@@ -8778,3 +8778,51 @@
{
return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
}
+
+int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
+{
+ struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_block_group_cache *cache = NULL;
+ u64 group_trimmed;
+ u64 start;
+ u64 end;
+ u64 trimmed = 0;
+ int ret = 0;
+
+ cache = btrfs_lookup_block_group(fs_info, range->start);
+
+ while (cache) {
+ if (cache->key.objectid >= (range->start + range->len)) {
+ btrfs_put_block_group(cache);
+ break;
+ }
+
+ start = max(range->start, cache->key.objectid);
+ end = min(range->start + range->len,
+ cache->key.objectid + cache->key.offset);
+
+ if (end - start >= range->minlen) {
+ if (!block_group_cache_done(cache)) {
+ ret = cache_block_group(cache, NULL, root, 0);
+ if (!ret)
+ wait_block_group_cache_done(cache);
+ }
+ ret = btrfs_trim_block_group(cache,
+ &group_trimmed,
+ start,
+ end,
+ range->minlen);
+
+ trimmed += group_trimmed;
+ if (ret) {
+ btrfs_put_block_group(cache);
+ break;
+ }
+ }
+
+ cache = next_block_group(fs_info->tree_root, cache);
+ }
+
+ range->len = trimmed;
+ return ret;
+}