Add new functions for triggering inode writeback
When btrfs is running low on metadata space, it needs to force delayed
allocation pages to disk. It currently does this with a suboptimal walk
of a private list of inodes with delayed allocation, and it would be
much better if we used the generic flusher threads.
writeback_inodes_sb_if_idle would be ideal, but it waits for the flusher
thread to start IO on all the dirty pages in the FS before it returns.
This adds variants of writeback_inodes_sb* that allow the caller to
control how many pages get sent down.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 72a5d64..a4cf845 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -60,7 +60,9 @@
struct bdi_writeback;
int inode_wait(void *);
void writeback_inodes_sb(struct super_block *);
+void writeback_inodes_sb_nr(struct super_block *, unsigned long nr);
int writeback_inodes_sb_if_idle(struct super_block *);
+int writeback_inodes_sb_nr_if_idle(struct super_block *, unsigned long nr);
void sync_inodes_sb(struct super_block *);
void writeback_inodes_wb(struct bdi_writeback *wb,
struct writeback_control *wbc);