Btrfs: add fragment=* debug mount option
In tracking down these weird bitmap problems it was helpful to artificially
create an extremely fragmented file system. These mount options let us either
fragment data or metadata or both. With these options I could reproduce all
sorts of weird latencies and hangs that occur under extreme fragmentation and
get them fixed. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 49bc792..1638423 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2145,6 +2145,8 @@
#define BTRFS_MOUNT_CHECK_INTEGRITY_INCLUDING_EXTENT_DATA (1 << 21)
#define BTRFS_MOUNT_PANIC_ON_FATAL_ERROR (1 << 22)
#define BTRFS_MOUNT_RESCAN_UUID_TREE (1 << 23)
+#define BTRFS_MOUNT_FRAGMENT_DATA (1 << 24)
+#define BTRFS_MOUNT_FRAGMENT_METADATA (1 << 25)
#define BTRFS_DEFAULT_COMMIT_INTERVAL (30)
#define BTRFS_DEFAULT_MAX_INLINE (8192)
@@ -2169,6 +2171,18 @@
btrfs_clear_opt(root->fs_info->mount_opt, opt); \
}
+#ifdef CONFIG_BTRFS_DEBUG
+static inline int
+btrfs_should_fragment_free_space(struct btrfs_root *root,
+ struct btrfs_block_group_cache *block_group)
+{
+ return (btrfs_test_opt(root, FRAGMENT_METADATA) &&
+ block_group->flags & BTRFS_BLOCK_GROUP_METADATA) ||
+ (btrfs_test_opt(root, FRAGMENT_DATA) &&
+ block_group->flags & BTRFS_BLOCK_GROUP_DATA);
+}
+#endif
+
/*
* Requests for changes that need to be done during transaction commit.
*