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/ctree.h b/fs/btrfs/ctree.h
index b305ae7..6532b60 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -77,6 +77,10 @@
/* orhpan objectid for tracking unlinked/truncated files */
#define BTRFS_ORPHAN_OBJECTID -5ULL
+/* does write ahead logging to speed up fsyncs */
+#define BTRFS_TREE_LOG_OBJECTID -6ULL
+#define BTRFS_TREE_LOG_FIXUP_OBJECTID -7ULL
+
/*
* All files have objectids higher than this.
*/
@@ -276,6 +280,7 @@
__le64 generation;
__le64 root;
__le64 chunk_root;
+ __le64 log_root;
__le64 total_bytes;
__le64 bytes_used;
__le64 root_dir_objectid;
@@ -287,6 +292,7 @@
__le32 sys_chunk_array_size;
u8 root_level;
u8 chunk_root_level;
+ u8 log_root_level;
struct btrfs_dev_item dev_item;
char label[BTRFS_LABEL_SIZE];
u8 sys_chunk_array[BTRFS_SYSTEM_CHUNK_ARRAY_SIZE];
@@ -392,7 +398,10 @@
* make a new item type
*/
struct btrfs_inode_item {
+ /* nfs style generation number */
__le64 generation;
+ /* transid that last touched this inode */
+ __le64 transid;
__le64 size;
__le64 nblocks;
__le64 block_group;
@@ -409,8 +418,13 @@
struct btrfs_timespec otime;
} __attribute__ ((__packed__));
+struct btrfs_dir_log_item {
+ __le64 end;
+} __attribute__ ((__packed__));
+
struct btrfs_dir_item {
struct btrfs_disk_key location;
+ __le64 transid;
__le16 data_len;
__le16 name_len;
u8 type;
@@ -505,6 +519,9 @@
struct btrfs_root *tree_root;
struct btrfs_root *chunk_root;
struct btrfs_root *dev_root;
+
+ /* the log root tree is a directory of all the other log roots */
+ struct btrfs_root *log_root_tree;
struct radix_tree_root fs_roots_radix;
struct extent_io_tree free_space_cache;
@@ -518,6 +535,7 @@
u64 generation;
u64 last_trans_committed;
+ u64 last_trans_new_blockgroup;
u64 open_ioctl_trans;
unsigned long mount_opt;
u64 max_extent;
@@ -527,6 +545,9 @@
wait_queue_head_t transaction_throttle;
wait_queue_head_t transaction_wait;
wait_queue_head_t async_submit_wait;
+
+ wait_queue_head_t tree_log_wait;
+
struct btrfs_super_block super_copy;
struct btrfs_super_block super_for_commit;
struct block_device *__bdev;
@@ -535,6 +556,7 @@
struct backing_dev_info bdi;
spinlock_t hash_lock;
struct mutex trans_mutex;
+ struct mutex tree_log_mutex;
struct mutex transaction_kthread_mutex;
struct mutex cleaner_mutex;
struct mutex alloc_mutex;
@@ -544,8 +566,13 @@
struct list_head trans_list;
struct list_head hashers;
struct list_head dead_roots;
+
atomic_t nr_async_submits;
atomic_t nr_async_bios;
+ atomic_t tree_log_writers;
+ atomic_t tree_log_commit;
+ unsigned long tree_log_batch;
+ u64 tree_log_transid;
/*
* this is used by the balancing code to wait for all the pending
@@ -583,6 +610,7 @@
struct completion kobj_unregister;
int do_barriers;
int closing;
+ int log_root_recovering;
atomic_t throttles;
atomic_t throttle_gen;
@@ -596,6 +624,7 @@
u64 delalloc_bytes;
u64 last_alloc;
u64 last_data_alloc;
+ u64 last_log_alloc;
spinlock_t ref_cache_lock;
u64 total_ref_cache_size;
@@ -632,6 +661,7 @@
struct btrfs_leaf_ref_tree *ref_tree;
struct btrfs_leaf_ref_tree ref_tree_struct;
struct btrfs_dirty_root *dirty_root;
+ struct btrfs_root *log_root;
struct btrfs_root_item root_item;
struct btrfs_key root_key;
@@ -640,6 +670,7 @@
struct kobject root_kobj;
struct completion kobj_unregister;
struct mutex objectid_mutex;
+ struct mutex log_mutex;
u64 objectid;
u64 last_trans;
@@ -692,6 +723,8 @@
* dir items are the name -> inode pointers in a directory. There is one
* for every name in a directory.
*/
+#define BTRFS_DIR_LOG_ITEM_KEY 14
+#define BTRFS_DIR_LOG_INDEX_KEY 15
#define BTRFS_DIR_ITEM_KEY 16
#define BTRFS_DIR_INDEX_KEY 17
/*
@@ -703,7 +736,8 @@
*/
#define BTRFS_CSUM_ITEM_KEY 19
-/* reserve 20-31 for other file stuff */
+
+/* reserve 21-31 for other file/dir stuff */
/*
* root items point to tree roots. There are typically in the root
@@ -938,6 +972,7 @@
/* struct btrfs_inode_item */
BTRFS_SETGET_FUNCS(inode_generation, struct btrfs_inode_item, generation, 64);
+BTRFS_SETGET_FUNCS(inode_transid, struct btrfs_inode_item, transid, 64);
BTRFS_SETGET_FUNCS(inode_size, struct btrfs_inode_item, size, 64);
BTRFS_SETGET_FUNCS(inode_nblocks, struct btrfs_inode_item, nblocks, 64);
BTRFS_SETGET_FUNCS(inode_block_group, struct btrfs_inode_item, block_group, 64);
@@ -1126,10 +1161,13 @@
write_eb_member(eb, item, struct btrfs_item, key, disk_key);
}
+BTRFS_SETGET_FUNCS(dir_log_end, struct btrfs_dir_log_item, end, 64);
+
/* struct btrfs_dir_item */
BTRFS_SETGET_FUNCS(dir_data_len, struct btrfs_dir_item, data_len, 16);
BTRFS_SETGET_FUNCS(dir_type, struct btrfs_dir_item, type, 8);
BTRFS_SETGET_FUNCS(dir_name_len, struct btrfs_dir_item, name_len, 16);
+BTRFS_SETGET_FUNCS(dir_transid, struct btrfs_dir_item, transid, 64);
static inline void btrfs_dir_item_key(struct extent_buffer *eb,
struct btrfs_dir_item *item,
@@ -1301,7 +1339,11 @@
BTRFS_SETGET_STACK_FUNCS(super_chunk_root, struct btrfs_super_block,
chunk_root, 64);
BTRFS_SETGET_STACK_FUNCS(super_chunk_root_level, struct btrfs_super_block,
- chunk_root_level, 64);
+ chunk_root_level, 8);
+BTRFS_SETGET_STACK_FUNCS(super_log_root, struct btrfs_super_block,
+ log_root, 64);
+BTRFS_SETGET_STACK_FUNCS(super_log_root_level, struct btrfs_super_block,
+ log_root_level, 8);
BTRFS_SETGET_STACK_FUNCS(super_total_bytes, struct btrfs_super_block,
total_bytes, 64);
BTRFS_SETGET_STACK_FUNCS(super_bytes_used, struct btrfs_super_block,
@@ -1405,6 +1447,12 @@
}
/* extent-tree.c */
+int btrfs_lookup_extent(struct btrfs_root *root, struct btrfs_path *path,
+ u64 start, u64 len);
+int btrfs_update_pinned_extents(struct btrfs_root *root,
+ u64 bytenr, u64 num, int pin);
+int btrfs_drop_leaf_ref(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root, struct extent_buffer *leaf);
int btrfs_cross_ref_exists(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_key *key, u64 bytenr);
@@ -1448,6 +1496,11 @@
u64 root_objectid, u64 ref_generation,
u64 owner, u64 owner_offset,
struct btrfs_key *ins);
+int btrfs_alloc_logged_extent(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ u64 root_objectid, u64 ref_generation,
+ u64 owner, u64 owner_offset,
+ struct btrfs_key *ins);
int btrfs_reserve_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 num_bytes, u64 min_alloc_size,
@@ -1488,9 +1541,9 @@
struct btrfs_key *key, int lowest_level,
int cache_only, u64 min_trans);
int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key,
+ struct btrfs_key *max_key,
struct btrfs_path *path, int cache_only,
u64 min_trans);
-
int btrfs_cow_block(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct extent_buffer *buf,
struct extent_buffer *parent, int parent_slot,
@@ -1656,6 +1709,18 @@
#define PageChecked PageFsMisc
#endif
+int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *dir, struct inode *inode,
+ const char *name, int name_len);
+int btrfs_add_link(struct btrfs_trans_handle *trans,
+ struct inode *parent_inode, struct inode *inode,
+ const char *name, int name_len, int add_backref, u64 index);
+int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
+ struct btrfs_root *root,
+ struct inode *inode, u64 new_size,
+ u32 min_type);
+
int btrfs_start_delalloc_inodes(struct btrfs_root *root);
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end);
int btrfs_writepages(struct address_space *mapping,
@@ -1715,6 +1780,7 @@
long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
/* file.c */
+int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync);
int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end);
int btrfs_check_file(struct btrfs_root *root, struct inode *inode);
extern struct file_operations btrfs_file_operations;