Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block

[karo-tx-linux.git] / include / linux / fs.h

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 5db7b1379d174848116124b5f9c26fc212798d21..e351da4a934f415b4ba0d2cc84acaa52c8120614 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -35,6 +35,7 @@
 #include <uapi/linux/fs.h>
 
 struct backing_dev_info;
+struct bdi_writeback;
 struct export_operations;
 struct hd_geometry;
 struct iovec;
@@ -634,6 +635,14 @@ struct inode {
 
        struct hlist_node       i_hash;
        struct list_head        i_wb_list;      /* backing dev IO list */
+#ifdef CONFIG_CGROUP_WRITEBACK
+       struct bdi_writeback    *i_wb;          /* the associated cgroup wb */
+
+       /* foreign inode detection, see wbc_detach_inode() */
+       int                     i_wb_frn_winner;
+       u16                     i_wb_frn_avg_time;
+       u16                     i_wb_frn_history;
+#endif
        struct list_head        i_lru;          /* inode LRU list */
        struct list_head        i_sb_list;
        union {
@@ -1232,6 +1241,8 @@ struct mm_struct;
 #define UMOUNT_NOFOLLOW        0x00000008      /* Don't follow symlink on umount */
 #define UMOUNT_UNUSED  0x80000000      /* Flag guaranteed to be unused */
 
+/* sb->s_iflags */
+#define SB_I_CGROUPWB  0x00000001      /* cgroup-aware writeback enabled */
 
 /* Possible states of 'frozen' field */
 enum {
@@ -1270,6 +1281,7 @@ struct super_block {
        const struct quotactl_ops       *s_qcop;
        const struct export_operations *s_export_op;
        unsigned long           s_flags;
+       unsigned long           s_iflags;       /* internal SB_I_* flags */
        unsigned long           s_magic;
        struct dentry           *s_root;
        struct rw_semaphore     s_umount;
@@ -1806,6 +1818,11 @@ struct super_operations {
  *
  * I_DIO_WAKEUP                Never set.  Only used as a key for wait_on_bit().
  *
+ * I_WB_SWITCH         Cgroup bdi_writeback switching in progress.  Used to
+ *                     synchronize competing switching instances and to tell
+ *                     wb stat updates to grab mapping->tree_lock.  See
+ *                     inode_switch_wb_work_fn() for details.
+ *
  * Q: What is the difference between I_WILL_FREE and I_FREEING?
  */
 #define I_DIRTY_SYNC           (1 << 0)
@@ -1825,6 +1842,7 @@ struct super_operations {
 #define I_DIRTY_TIME           (1 << 11)
 #define __I_DIRTY_TIME_EXPIRED 12
 #define I_DIRTY_TIME_EXPIRED   (1 << __I_DIRTY_TIME_EXPIRED)
+#define I_WB_SWITCH            (1 << 13)
 
 #define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
 #define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)
@@ -2241,7 +2259,13 @@ extern struct super_block *freeze_bdev(struct block_device *);
 extern void emergency_thaw_all(void);
 extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
 extern int fsync_bdev(struct block_device *);
-extern int sb_is_blkdev_sb(struct super_block *sb);
+
+extern struct super_block *blockdev_superblock;
+
+static inline bool sb_is_blkdev_sb(struct super_block *sb)
+{
+       return sb == blockdev_superblock;
+}
 #else
 static inline void bd_forget(struct inode *inode) {}
 static inline int sync_blockdev(struct block_device *bdev) { return 0; }