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, 20 insertions, 0 deletions

diff --git a/fs/btrfs/inode-map.c b/fs/btrfs/inode-map.c
index 2d0d50067a7b..cb79b8975c9f 100644
--- a/fs/btrfs/inode-map.c
+++ b/fs/btrfs/inode-map.c
@@ -38,6 +38,9 @@ static int caching_kthread(void *data)
         int slot;
         int ret;
 
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return 0;
+
         path = btrfs_alloc_path();
         if (!path)
                 return -ENOMEM;
@@ -141,6 +144,9 @@ static void start_caching(struct btrfs_root *root)
         int ret;
         u64 objectid;
 
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return;
+
         spin_lock(&root->cache_lock);
         if (root->cached != BTRFS_CACHE_NO) {
                 spin_unlock(&root->cache_lock);
@@ -178,6 +184,9 @@ static void start_caching(struct btrfs_root *root)
 
 int btrfs_find_free_ino(struct btrfs_root *root, u64 *objectid)
 {
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return btrfs_find_free_objectid(root, objectid);
+
 again:
         *objectid = btrfs_find_ino_for_alloc(root);
 
@@ -201,6 +210,10 @@ void btrfs_return_ino(struct btrfs_root *root, u64 objectid)
 {
         struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
         struct btrfs_free_space_ctl *pinned = root->free_ino_pinned;
+
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return;
+
 again:
         if (root->cached == BTRFS_CACHE_FINISHED) {
                 __btrfs_add_free_space(ctl, objectid, 1);
@@ -250,6 +263,9 @@ void btrfs_unpin_free_ino(struct btrfs_root *root)
         struct rb_node *n;
         u64 count;
 
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return;
+
         while (1) {
                 n = rb_first(rbroot);
                 if (!n)
@@ -399,9 +415,13 @@ int btrfs_save_ino_cache(struct btrfs_root *root,
             root != root->fs_info->tree_root)
                 return 0;
 
+        if (!btrfs_test_opt(root, INODE_MAP_CACHE))
+                return 0;
+
         path = btrfs_alloc_path();
         if (!path)
                 return -ENOMEM;
+
 again:
         inode = lookup_free_ino_inode(root, path);
         if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {