Btrfs: use the commit_root for reading free_space_inode crcs

[pandora-kernel.git] / fs / btrfs / file-item.c

diff --git a/fs/btrfs/file-item.c b/fs/btrfs/file-item.c
index bb22a44..08bcfa9 100644 (file)
--- a/fs/btrfs/file-item.c
+++ b/fs/btrfs/file-item.c
@@ -177,6 +177,15 @@ static int __btrfs_lookup_bio_sums(struct btrfs_root *root,
 
        WARN_ON(bio->bi_vcnt <= 0);
 
+       /*
+        * the free space stuff is only read when it hasn't been
+        * updated in the current transaction.  So, we can safely
+        * read from the commit root and sidestep a nasty deadlock
+        * between reading the free space cache and updating the csum tree.
+        */
+       if (btrfs_is_free_space_inode(root, inode))
+               path->search_commit_root = 1;
+
        disk_bytenr = (u64)bio->bi_sector << 9;
        if (dio)
                offset = logical_offset;