Btrfs: read device stats on mount, write modified ones during commit

[linux-2.6-block.git] / fs / btrfs / ctree.h

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 3f65a812e282d00744e9de5b89acc09ead08acb8..e176f8c551f7b752352715869797b284e330a4b2 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -823,6 +823,14 @@ struct btrfs_csum_item {
        u8 csum;
 } __attribute__ ((__packed__));
 
+struct btrfs_dev_stats_item {
+       /*
+        * grow this item struct at the end for future enhancements and keep
+        * the existing values unchanged
+        */
+       __le64 values[BTRFS_DEV_STAT_VALUES_MAX];
+} __attribute__ ((__packed__));
+
 /* different types of block groups (and chunks) */
 #define BTRFS_BLOCK_GROUP_DATA         (1ULL << 0)
 #define BTRFS_BLOCK_GROUP_SYSTEM       (1ULL << 1)
@@ -1078,7 +1086,7 @@ struct btrfs_fs_info {
         * is required instead of the faster short fsync log commits
         */
        u64 last_trans_log_full_commit;
-       unsigned long mount_opt:21;
+       unsigned long mount_opt;
        unsigned long compress_type:4;
        u64 max_inline;
        u64 alloc_start;
@@ -1375,7 +1383,7 @@ struct btrfs_root {
        struct list_head root_list;
 
        spinlock_t orphan_lock;
-       struct list_head orphan_list;
+       atomic_t orphan_inodes;
        struct btrfs_block_rsv *orphan_block_rsv;
        int orphan_item_inserted;
        int orphan_cleanup_state;
@@ -1507,6 +1515,12 @@ struct btrfs_ioctl_defrag_range_args {
 
 #define BTRFS_BALANCE_ITEM_KEY 248
 
+/*
+ * Persistantly stores the io stats in the device tree.
+ * One key for all stats, (0, BTRFS_DEV_STATS_KEY, devid).
+ */
+#define BTRFS_DEV_STATS_KEY    249
+
 /*
  * string items are for debugging.  They just store a short string of
  * data in the FS
@@ -2415,6 +2429,30 @@ static inline u32 btrfs_file_extent_inline_item_len(struct extent_buffer *eb,
        return btrfs_item_size(eb, e) - offset;
 }
 
+/* btrfs_dev_stats_item */
+static inline u64 btrfs_dev_stats_value(struct extent_buffer *eb,
+                                       struct btrfs_dev_stats_item *ptr,
+                                       int index)
+{
+       u64 val;
+
+       read_extent_buffer(eb, &val,
+                          offsetof(struct btrfs_dev_stats_item, values) +
+                           ((unsigned long)ptr) + (index * sizeof(u64)),
+                          sizeof(val));
+       return val;
+}
+
+static inline void btrfs_set_dev_stats_value(struct extent_buffer *eb,
+                                            struct btrfs_dev_stats_item *ptr,
+                                            int index, u64 val)
+{
+       write_extent_buffer(eb, &val,
+                           offsetof(struct btrfs_dev_stats_item, values) +
+                            ((unsigned long)ptr) + (index * sizeof(u64)),
+                           sizeof(val));
+}
+
 static inline struct btrfs_fs_info *btrfs_sb(struct super_block *sb)
 {
        return sb->s_fs_info;