Btrfs: Add a write ahead tree log to optimize synchronous operations
File syncs and directory syncs are optimized by copying their
items into a special (copy-on-write) log tree. There is one log tree per
subvolume and the btrfs super block points to a tree of log tree roots.
After a crash, items are copied out of the log tree and back into the
subvolume. See tree-log.c for all the details.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/compat.h b/fs/btrfs/compat.h
index d45fb37..b0ed188 100644
--- a/fs/btrfs/compat.h
+++ b/fs/btrfs/compat.h
@@ -22,6 +22,21 @@
}
#endif
+#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
+static inline void btrfs_drop_nlink(struct inode *inode)
+{
+ inode->i_nlink--;
+}
+
+static inline void btrfs_inc_nlink(struct inode *inode)
+{
+ inode->i_nlink++;
+}
+#else
+# define btrfs_drop_nlink(inode) drop_nlink(inode)
+# define btrfs_inc_nlink(inode) inc_nlink(inode)
+#endif
+
/*
* Even if AppArmor isn't enabled, it still has different prototypes.
* Add more distro/version pairs here to declare which has AppArmor applied.