btrfs: add missing discards when unpinning extents with -o discard

[mirror_ubuntu-artful-kernel.git] / fs / btrfs / free-space-cache.c

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 41c510b7cc110891bbc3818638137e3e516d5800..abe3a66bd3ba6d31f9fb072c6d4d6c6be42c174e 100644 (file)
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -86,7 +86,7 @@ static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
 
        mapping_set_gfp_mask(inode->i_mapping,
                        mapping_gfp_mask(inode->i_mapping) &
-                       ~(GFP_NOFS & ~__GFP_HIGHMEM));
+                       ~(__GFP_FS | __GFP_HIGHMEM));
 
        return inode;
 }
@@ -231,6 +231,7 @@ int btrfs_truncate_free_space_cache(struct btrfs_root *root,
 {
        int ret = 0;
        struct btrfs_path *path = btrfs_alloc_path();
+       bool locked = false;
 
        if (!path) {
                ret = -ENOMEM;
@@ -238,6 +239,7 @@ int btrfs_truncate_free_space_cache(struct btrfs_root *root,
        }
 
        if (block_group) {
+               locked = true;
                mutex_lock(&trans->transaction->cache_write_mutex);
                if (!list_empty(&block_group->io_list)) {
                        list_del_init(&block_group->io_list);
@@ -269,18 +271,14 @@ int btrfs_truncate_free_space_cache(struct btrfs_root *root,
         */
        ret = btrfs_truncate_inode_items(trans, root, inode,
                                         0, BTRFS_EXTENT_DATA_KEY);
-       if (ret) {
-               mutex_unlock(&trans->transaction->cache_write_mutex);
-               btrfs_abort_transaction(trans, root, ret);
-               return ret;
-       }
+       if (ret)
+               goto fail;
 
        ret = btrfs_update_inode(trans, root, inode);
 
-       if (block_group)
-               mutex_unlock(&trans->transaction->cache_write_mutex);
-
 fail:
+       if (locked)
+               mutex_unlock(&trans->transaction->cache_write_mutex);
        if (ret)
                btrfs_abort_transaction(trans, root, ret);
 
@@ -3274,35 +3272,23 @@ next:
        return ret;
 }
 
-int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
-                          u64 *trimmed, u64 start, u64 end, u64 minlen)
+void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache)
 {
-       int ret;
+       atomic_inc(&cache->trimming);
+}
 
-       *trimmed = 0;
+void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
+{
+       struct extent_map_tree *em_tree;
+       struct extent_map *em;
+       bool cleanup;
 
        spin_lock(&block_group->lock);
-       if (block_group->removed) {
-               spin_unlock(&block_group->lock);
-               return 0;
-       }
-       atomic_inc(&block_group->trimming);
+       cleanup = (atomic_dec_and_test(&block_group->trimming) &&
+                  block_group->removed);
        spin_unlock(&block_group->lock);
 
-       ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
-       if (ret)
-               goto out;
-
-       ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
-out:
-       spin_lock(&block_group->lock);
-       if (atomic_dec_and_test(&block_group->trimming) &&
-           block_group->removed) {
-               struct extent_map_tree *em_tree;
-               struct extent_map *em;
-
-               spin_unlock(&block_group->lock);
-
+       if (cleanup) {
                lock_chunks(block_group->fs_info->chunk_root);
                em_tree = &block_group->fs_info->mapping_tree.map_tree;
                write_lock(&em_tree->lock);
@@ -3326,10 +3312,31 @@ out:
                 * this block group have left 1 entry each one. Free them.
                 */
                __btrfs_remove_free_space_cache(block_group->free_space_ctl);
-       } else {
+       }
+}
+
+int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
+                          u64 *trimmed, u64 start, u64 end, u64 minlen)
+{
+       int ret;
+
+       *trimmed = 0;
+
+       spin_lock(&block_group->lock);
+       if (block_group->removed) {
                spin_unlock(&block_group->lock);
+               return 0;
        }
+       btrfs_get_block_group_trimming(block_group);
+       spin_unlock(&block_group->lock);
+
+       ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
+       if (ret)
+               goto out;
 
+       ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
+out:
+       btrfs_put_block_group_trimming(block_group);
        return ret;
 }
 
@@ -3466,6 +3473,7 @@ int btrfs_write_out_ino_cache(struct btrfs_root *root,
        struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
        int ret;
        struct btrfs_io_ctl io_ctl;
+       bool release_metadata = true;
 
        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
                return 0;
@@ -3473,11 +3481,20 @@ int btrfs_write_out_ino_cache(struct btrfs_root *root,
        memset(&io_ctl, 0, sizeof(io_ctl));
        ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl,
                                      trans, path, 0);
-       if (!ret)
+       if (!ret) {
+               /*
+                * At this point writepages() didn't error out, so our metadata
+                * reservation is released when the writeback finishes, at
+                * inode.c:btrfs_finish_ordered_io(), regardless of it finishing
+                * with or without an error.
+                */
+               release_metadata = false;
                ret = btrfs_wait_cache_io(root, trans, NULL, &io_ctl, path, 0);
+       }
 
        if (ret) {
-               btrfs_delalloc_release_metadata(inode, inode->i_size);
+               if (release_metadata)
+                       btrfs_delalloc_release_metadata(inode, inode->i_size);
 #ifdef DEBUG
                btrfs_err(root->fs_info,
                        "failed to write free ino cache for root %llu",