struct btrfs_space_info *space_info;
struct btrfs_trans_handle *trans;
u64 delalloc_bytes;
- u64 max_reclaim;
+ u64 async_pages;
u64 items;
long time_left;
unsigned long nr_pages;
loops = 0;
while (delalloc_bytes && loops < 3) {
- max_reclaim = min(delalloc_bytes, to_reclaim);
- nr_pages = max_reclaim >> PAGE_SHIFT;
+ nr_pages = min(delalloc_bytes, to_reclaim) >> PAGE_SHIFT;
+
+ /*
+ * Triggers inode writeback for up to nr_pages. This will invoke
+ * ->writepages callback and trigger delalloc filling
+ * (btrfs_run_delalloc_range()).
+ */
btrfs_writeback_inodes_sb_nr(fs_info, nr_pages, items);
+
/*
- * We need to wait for the async pages to actually start before
- * we do anything.
+ * We need to wait for the compressed pages to start before
+ * we continue.
*/
- max_reclaim = atomic_read(&fs_info->async_delalloc_pages);
- if (!max_reclaim)
+ async_pages = atomic_read(&fs_info->async_delalloc_pages);
+ if (!async_pages)
goto skip_async;
- if (max_reclaim <= nr_pages)
- max_reclaim = 0;
+ /*
+ * Calculate how many compressed pages we want to be written
+ * before we continue. I.e if there are more async pages than we
+ * require wait_event will wait until nr_pages are written.
+ */
+ if (async_pages <= nr_pages)
+ async_pages = 0;
else
- max_reclaim -= nr_pages;
+ async_pages -= nr_pages;
wait_event(fs_info->async_submit_wait,
atomic_read(&fs_info->async_delalloc_pages) <=
- (int)max_reclaim);
+ (int)async_pages);
skip_async:
spin_lock(&space_info->lock);
if (list_empty(&space_info->tickets) &&