net: smc91x: fix SMC accesses

[firefly-linux-kernel-4.4.55.git] / include / linux / writeback.h

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 3b73e97ecfc711896b7aab4045f2b3e9e9dff704..d0b5ca5d4e080346e8a657c6c6aee540e47776e7 100644 (file)
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -8,6 +8,7 @@
 #include <linux/workqueue.h>
 #include <linux/fs.h>
 #include <linux/flex_proportions.h>
+#include <linux/backing-dev-defs.h>
 
 DECLARE_PER_CPU(int, dirty_throttle_leaks);
 
@@ -85,6 +86,18 @@ struct writeback_control {
        unsigned for_reclaim:1;         /* Invoked from the page allocator */
        unsigned range_cyclic:1;        /* range_start is cyclic */
        unsigned for_sync:1;            /* sync(2) WB_SYNC_ALL writeback */
+#ifdef CONFIG_CGROUP_WRITEBACK
+       struct bdi_writeback *wb;       /* wb this writeback is issued under */
+       struct inode *inode;            /* inode being written out */
+
+       /* foreign inode detection, see wbc_detach_inode() */
+       int wb_id;                      /* current wb id */
+       int wb_lcand_id;                /* last foreign candidate wb id */
+       int wb_tcand_id;                /* this foreign candidate wb id */
+       size_t wb_bytes;                /* bytes written by current wb */
+       size_t wb_lcand_bytes;          /* bytes written by last candidate */
+       size_t wb_tcand_bytes;          /* bytes written by this candidate */
+#endif
 };
 
 /*
@@ -173,6 +186,128 @@ static inline void wait_on_inode(struct inode *inode)
        wait_on_bit(&inode->i_state, __I_NEW, TASK_UNINTERRUPTIBLE);
 }
 
+#ifdef CONFIG_CGROUP_WRITEBACK
+
+#include <linux/cgroup.h>
+#include <linux/bio.h>
+
+void __inode_attach_wb(struct inode *inode, struct page *page);
+void wbc_attach_and_unlock_inode(struct writeback_control *wbc,
+                                struct inode *inode)
+       __releases(&inode->i_lock);
+void wbc_detach_inode(struct writeback_control *wbc);
+void wbc_account_io(struct writeback_control *wbc, struct page *page,
+                   size_t bytes);
+void cgroup_writeback_umount(void);
+
+/**
+ * inode_attach_wb - associate an inode with its wb
+ * @inode: inode of interest
+ * @page: page being dirtied (may be NULL)
+ *
+ * If @inode doesn't have its wb, associate it with the wb matching the
+ * memcg of @page or, if @page is NULL, %current.  May be called w/ or w/o
+ * @inode->i_lock.
+ */
+static inline void inode_attach_wb(struct inode *inode, struct page *page)
+{
+       if (!inode->i_wb)
+               __inode_attach_wb(inode, page);
+}
+
+/**
+ * inode_detach_wb - disassociate an inode from its wb
+ * @inode: inode of interest
+ *
+ * @inode is being freed.  Detach from its wb.
+ */
+static inline void inode_detach_wb(struct inode *inode)
+{
+       if (inode->i_wb) {
+               wb_put(inode->i_wb);
+               inode->i_wb = NULL;
+       }
+}
+
+/**
+ * wbc_attach_fdatawrite_inode - associate wbc and inode for fdatawrite
+ * @wbc: writeback_control of interest
+ * @inode: target inode
+ *
+ * This function is to be used by __filemap_fdatawrite_range(), which is an
+ * alternative entry point into writeback code, and first ensures @inode is
+ * associated with a bdi_writeback and attaches it to @wbc.
+ */
+static inline void wbc_attach_fdatawrite_inode(struct writeback_control *wbc,
+                                              struct inode *inode)
+{
+       spin_lock(&inode->i_lock);
+       inode_attach_wb(inode, NULL);
+       wbc_attach_and_unlock_inode(wbc, inode);
+}
+
+/**
+ * wbc_init_bio - writeback specific initializtion of bio
+ * @wbc: writeback_control for the writeback in progress
+ * @bio: bio to be initialized
+ *
+ * @bio is a part of the writeback in progress controlled by @wbc.  Perform
+ * writeback specific initialization.  This is used to apply the cgroup
+ * writeback context.
+ */
+static inline void wbc_init_bio(struct writeback_control *wbc, struct bio *bio)
+{
+       /*
+        * pageout() path doesn't attach @wbc to the inode being written
+        * out.  This is intentional as we don't want the function to block
+        * behind a slow cgroup.  Ultimately, we want pageout() to kick off
+        * regular writeback instead of writing things out itself.
+        */
+       if (wbc->wb)
+               bio_associate_blkcg(bio, wbc->wb->blkcg_css);
+}
+
+#else  /* CONFIG_CGROUP_WRITEBACK */
+
+static inline void inode_attach_wb(struct inode *inode, struct page *page)
+{
+}
+
+static inline void inode_detach_wb(struct inode *inode)
+{
+}
+
+static inline void wbc_attach_and_unlock_inode(struct writeback_control *wbc,
+                                              struct inode *inode)
+       __releases(&inode->i_lock)
+{
+       spin_unlock(&inode->i_lock);
+}
+
+static inline void wbc_attach_fdatawrite_inode(struct writeback_control *wbc,
+                                              struct inode *inode)
+{
+}
+
+static inline void wbc_detach_inode(struct writeback_control *wbc)
+{
+}
+
+static inline void wbc_init_bio(struct writeback_control *wbc, struct bio *bio)
+{
+}
+
+static inline void wbc_account_io(struct writeback_control *wbc,
+                                 struct page *page, size_t bytes)
+{
+}
+
+static inline void cgroup_writeback_umount(void)
+{
+}
+
+#endif /* CONFIG_CGROUP_WRITEBACK */
+
 /*
  * mm/page-writeback.c
  */