Btrfs: add mount -o inode_cache

This makes the inode map cache default to off until we
fix the overflow problem when the free space crcs don't fit
inside a single page.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 1cb72394498c..bffa5c4a633b 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2536,6 +2536,9 @@ int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
         int ret = 0;
         u64 root_gen = btrfs_root_generation(&root->root_item);
 
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return 0;
+
         /*
          * If we're unmounting then just return, since this does a search on the
          * normal root and not the commit root and we could deadlock.
@@ -2575,6 +2578,9 @@ int btrfs_write_out_ino_cache(struct btrfs_root *root,
         struct inode *inode;
         int ret;
 
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return 0;
+
         inode = lookup_free_ino_inode(root, path);
         if (IS_ERR(inode))
                 return 0;