1 files changed, 16 insertions, 0 deletions

diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 4d5cd9624bb3..38c058bcf359 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -761,10 +761,26 @@ void __init btrfs_init_compress(void)
         int i;
 
         for (i = 0; i < BTRFS_COMPRESS_TYPES; i++) {
+                struct list_head *workspace;
+
                 INIT_LIST_HEAD(&btrfs_comp_ws[i].idle_ws);
                 spin_lock_init(&btrfs_comp_ws[i].ws_lock);
                 atomic_set(&btrfs_comp_ws[i].total_ws, 0);
                 init_waitqueue_head(&btrfs_comp_ws[i].ws_wait);
+
+                /*
+                 * Preallocate one workspace for each compression type so
+                 * we can guarantee forward progress in the worst case
+                 */
+                workspace = btrfs_compress_op[i]->alloc_workspace();
+                if (IS_ERR(workspace)) {
+                        printk(KERN_WARNING
+        "BTRFS: cannot preallocate compression workspace, will try later");
+                } else {
+                        atomic_set(&btrfs_comp_ws[i].total_ws, 1);
+                        btrfs_comp_ws[i].free_ws = 1;
+                        list_add(workspace, &btrfs_comp_ws[i].idle_ws);
+                }
         }
 }