writeback: make backing_dev_info host cgroup-specific bdi_writebacks

[linux-2.6-microblaze.git] / include / linux / fs.h

diff --git a/include/linux/fs.h b/include/linux/fs.h
index c7496f2..67a42ec 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;
@@ -635,6 +636,9 @@ 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 */
+#endif
        struct list_head        i_lru;          /* inode LRU list */
        struct list_head        i_sb_list;
        union {
@@ -1820,7 +1824,7 @@ struct super_operations {
 #define I_SYNC                 (1 << __I_SYNC)
 #define I_REFERENCED           (1 << 8)
 #define __I_DIO_WAKEUP         9
-#define I_DIO_WAKEUP           (1 << I_DIO_WAKEUP)
+#define I_DIO_WAKEUP           (1 << __I_DIO_WAKEUP)
 #define I_LINKABLE             (1 << 10)
 #define I_DIRTY_TIME           (1 << 11)
 #define __I_DIRTY_TIME_EXPIRED 12
@@ -1897,6 +1901,7 @@ struct file_system_type {
 #define FS_HAS_SUBTYPE         4
 #define FS_USERNS_MOUNT                8       /* Can be mounted by userns root */
 #define FS_USERNS_DEV_MOUNT    16 /* A userns mount does not imply MNT_NODEV */
+#define FS_CGROUP_WRITEBACK    32      /* Supports cgroup-aware writeback */
 #define FS_RENAME_DOES_D_MOVE  32768   /* FS will handle d_move() during rename() internally. */
        struct dentry *(*mount) (struct file_system_type *, int,
                       const char *, void *);
@@ -2240,7 +2245,13 @@ 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; }
@@ -2279,6 +2290,9 @@ extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
 extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,
                                              void *holder);
 extern void blkdev_put(struct block_device *bdev, fmode_t mode);
+extern int __blkdev_reread_part(struct block_device *bdev);
+extern int blkdev_reread_part(struct block_device *bdev);
+
 #ifdef CONFIG_SYSFS
 extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
 extern void bd_unlink_disk_holder(struct block_device *bdev,
@@ -2644,6 +2658,9 @@ enum {
 
        /* filesystem can handle aio writes beyond i_size */
        DIO_ASYNC_EXTEND = 0x04,
+
+       /* inode/fs/bdev does not need truncate protection */
+       DIO_SKIP_DIO_COUNT = 0x08,
 };
 
 void dio_end_io(struct bio *bio, int error);
@@ -2666,7 +2683,31 @@ static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,
 #endif
 
 void inode_dio_wait(struct inode *inode);
-void inode_dio_done(struct inode *inode);
+
+/*
+ * inode_dio_begin - signal start of a direct I/O requests
+ * @inode: inode the direct I/O happens on
+ *
+ * This is called once we've finished processing a direct I/O request,
+ * and is used to wake up callers waiting for direct I/O to be quiesced.
+ */
+static inline void inode_dio_begin(struct inode *inode)
+{
+       atomic_inc(&inode->i_dio_count);
+}
+
+/*
+ * inode_dio_end - signal finish of a direct I/O requests
+ * @inode: inode the direct I/O happens on
+ *
+ * This is called once we've finished processing a direct I/O request,
+ * and is used to wake up callers waiting for direct I/O to be quiesced.
+ */
+static inline void inode_dio_end(struct inode *inode)
+{
+       if (atomic_dec_and_test(&inode->i_dio_count))
+               wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
+}
 
 extern void inode_set_flags(struct inode *inode, unsigned int flags,
                            unsigned int mask);