1 files changed, 118 insertions, 0 deletions

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
new file mode 100644
index 000000000000..1262cb43c3ab
--- /dev/null
+++ b/include/linux/writeback.h
@@ -0,0 +1,118 @@
+/*
+ * include/linux/writeback.h.
+ */
+#ifndef WRITEBACK_H
+#define WRITEBACK_H
+
+struct backing_dev_info;
+
+extern spinlock_t inode_lock;
+extern struct list_head inode_in_use;
+extern struct list_head inode_unused;
+
+/*
+ * Yes, writeback.h requires sched.h
+ * No, sched.h is not included from here.
+ */
+static inline int current_is_pdflush(void)
+{
+        return current->flags & PF_FLUSHER;
+}
+
+/*
+ * fs/fs-writeback.c
+ */
+enum writeback_sync_modes {
+        WB_SYNC_NONE,   /* Don't wait on anything */
+        WB_SYNC_ALL,    /* Wait on every mapping */
+        WB_SYNC_HOLD,   /* Hold the inode on sb_dirty for sys_sync() */
+};
+
+/*
+ * A control structure which tells the writeback code what to do.  These are
+ * always on the stack, and hence need no locking.  They are always initialised
+ * in a manner such that unspecified fields are set to zero.
+ */
+struct writeback_control {
+        struct backing_dev_info *bdi;   /* If !NULL, only write back this
+                                           queue */
+        enum writeback_sync_modes sync_mode;
+        unsigned long *older_than_this; /* If !NULL, only write back inodes
+                                           older than this */
+        long nr_to_write;               /* Write this many pages, and decrement
+                                           this for each page written */
+        long pages_skipped;             /* Pages which were not written */
+
+        /*
+         * For a_ops->writepages(): is start or end are non-zero then this is
+         * a hint that the filesystem need only write out the pages inside that
+         * byterange.  The byte at `end' is included in the writeout request.
+         */
+        loff_t start;
+        loff_t end;
+
+        unsigned nonblocking:1;                 /* Don't get stuck on request queues */
+        unsigned encountered_congestion:1;      /* An output: a queue is full */
+        unsigned for_kupdate:1;                 /* A kupdate writeback */
+        unsigned for_reclaim:1;                 /* Invoked from the page allocator */
+};
+
+/*
+ * ->writepage() return values (make these much larger than a pagesize, in
+ * case some fs is returning number-of-bytes-written from writepage)
+ */
+#define WRITEPAGE_ACTIVATE      0x80000 /* IO was not started: activate page */
+
+/*
+ * fs/fs-writeback.c
+ */     
+void writeback_inodes(struct writeback_control *wbc);
+void wake_up_inode(struct inode *inode);
+int inode_wait(void *);
+void sync_inodes_sb(struct super_block *, int wait);
+void sync_inodes(int wait);
+
+/* writeback.h requires fs.h; it, too, is not included from here. */
+static inline void wait_on_inode(struct inode *inode)
+{
+        might_sleep();
+        wait_on_bit(&inode->i_state, __I_LOCK, inode_wait,
+                                                        TASK_UNINTERRUPTIBLE);
+}
+
+/*
+ * mm/page-writeback.c
+ */
+int wakeup_bdflush(long nr_pages);
+void laptop_io_completion(void);
+void laptop_sync_completion(void);
+void throttle_vm_writeout(void);
+
+/* These are exported to sysctl. */
+extern int dirty_background_ratio;
+extern int vm_dirty_ratio;
+extern int dirty_writeback_centisecs;
+extern int dirty_expire_centisecs;
+extern int block_dump;
+extern int laptop_mode;
+
+struct ctl_table;
+struct file;
+int dirty_writeback_centisecs_handler(struct ctl_table *, int, struct file *,
+                                      void __user *, size_t *, loff_t *);
+
+void page_writeback_init(void);
+void balance_dirty_pages_ratelimited(struct address_space *mapping);
+int pdflush_operation(void (*fn)(unsigned long), unsigned long arg0);
+int do_writepages(struct address_space *mapping, struct writeback_control *wbc);
+int sync_page_range(struct inode *inode, struct address_space *mapping,
+                        loff_t pos, size_t count);
+int sync_page_range_nolock(struct inode *inode, struct address_space
+                *mapping, loff_t pos, size_t count);
+
+/* pdflush.c */
+extern int nr_pdflush_threads;  /* Global so it can be exported to sysctl
+                                   read-only. */
+
+
+#endif          /* WRITEBACK_H */