Btrfs: do not do fast caching if we are allocating blocks for tree_root

[pandora-kernel.git] / fs / btrfs / extent-tree.c

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index df75410..cec05e1 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -429,6 +429,7 @@ err:
 
 static int cache_block_group(struct btrfs_block_group_cache *cache,
                             struct btrfs_trans_handle *trans,
+                            struct btrfs_root *root,
                             int load_cache_only)
 {
        struct btrfs_fs_info *fs_info = cache->fs_info;
@@ -442,9 +443,12 @@ static int cache_block_group(struct btrfs_block_group_cache *cache,
 
        /*
         * We can't do the read from on-disk cache during a commit since we need
-        * to have the normal tree locking.
+        * to have the normal tree locking.  Also if we are currently trying to
+        * allocate blocks for the tree root we can't do the fast caching since
+        * we likely hold important locks.
         */
-       if (!trans->transaction->in_commit) {
+       if (!trans->transaction->in_commit &&
+           (root && root != root->fs_info->tree_root)) {
                spin_lock(&cache->lock);
                if (cache->cached != BTRFS_CACHE_NO) {
                        spin_unlock(&cache->lock);
@@ -2742,6 +2746,7 @@ static int cache_save_setup(struct btrfs_block_group_cache *block_group,
        struct btrfs_root *root = block_group->fs_info->tree_root;
        struct inode *inode = NULL;
        u64 alloc_hint = 0;
+       int dcs = BTRFS_DC_ERROR;
        int num_pages = 0;
        int retries = 0;
        int ret = 0;
@@ -2796,6 +2801,8 @@ again:
 
        spin_lock(&block_group->lock);
        if (block_group->cached != BTRFS_CACHE_FINISHED) {
+               /* We're not cached, don't bother trying to write stuff out */
+               dcs = BTRFS_DC_WRITTEN;
                spin_unlock(&block_group->lock);
                goto out_put;
        }
@@ -2822,6 +2829,8 @@ again:
        ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages,
                                              num_pages, num_pages,
                                              &alloc_hint);
+       if (!ret)
+               dcs = BTRFS_DC_SETUP;
        btrfs_free_reserved_data_space(inode, num_pages);
 out_put:
        iput(inode);
@@ -2829,10 +2838,7 @@ out_free:
        btrfs_release_path(root, path);
 out:
        spin_lock(&block_group->lock);
-       if (ret)
-               block_group->disk_cache_state = BTRFS_DC_ERROR;
-       else
-               block_group->disk_cache_state = BTRFS_DC_SETUP;
+       block_group->disk_cache_state = dcs;
        spin_unlock(&block_group->lock);
 
        return ret;
@@ -3413,7 +3419,7 @@ again:
         * our reservation.
         */
        if (unused <= space_info->total_bytes) {
-               unused -= space_info->total_bytes;
+               unused = space_info->total_bytes - unused;
                if (unused >= num_bytes) {
                        if (!reserved)
                                space_info->bytes_reserved += orig_bytes;
@@ -3607,18 +3613,14 @@ struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root)
 {
        struct btrfs_block_rsv *block_rsv;
        struct btrfs_fs_info *fs_info = root->fs_info;
-       u64 alloc_target;
 
        block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS);
        if (!block_rsv)
                return NULL;
 
        btrfs_init_block_rsv(block_rsv);
-
-       alloc_target = btrfs_get_alloc_profile(root, 0);
        block_rsv->space_info = __find_space_info(fs_info,
                                                  BTRFS_BLOCK_GROUP_METADATA);
-
        return block_rsv;
 }
 
@@ -4085,7 +4087,7 @@ static int update_block_group(struct btrfs_trans_handle *trans,
                 * space back to the block group, otherwise we will leak space.
                 */
                if (!alloc && cache->cached == BTRFS_CACHE_NO)
-                       cache_block_group(cache, trans, 1);
+                       cache_block_group(cache, trans, NULL, 1);
 
                byte_in_group = bytenr - cache->key.objectid;
                WARN_ON(byte_in_group > cache->key.offset);
@@ -4939,7 +4941,8 @@ have_block_group:
                if (unlikely(block_group->cached == BTRFS_CACHE_NO)) {
                        u64 free_percent;
 
-                       ret = cache_block_group(block_group, trans, 1);
+                       ret = cache_block_group(block_group, trans,
+                                               orig_root, 1);
                        if (block_group->cached == BTRFS_CACHE_FINISHED)
                                goto have_block_group;
 
@@ -4963,7 +4966,8 @@ have_block_group:
                        if (loop > LOOP_CACHING_NOWAIT ||
                            (loop > LOOP_FIND_IDEAL &&
                             atomic_read(&space_info->caching_threads) < 2)) {
-                               ret = cache_block_group(block_group, trans, 0);
+                               ret = cache_block_group(block_group, trans,
+                                                       orig_root, 0);
                                BUG_ON(ret);
                        }
                        found_uncached_bg = true;
@@ -5520,7 +5524,7 @@ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans,
        u64 num_bytes = ins->offset;
 
        block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid);
-       cache_block_group(block_group, trans, 0);
+       cache_block_group(block_group, trans, NULL, 0);
        caching_ctl = get_caching_control(block_group);
 
        if (!caching_ctl) {