Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[firefly-linux-kernel-4.4.55.git] / fs / nilfs2 / the_nilfs.h

diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h
index d01ead1bea9a738a5268908fe321eed19af3cc07..23778d385836f56c9cad3be7aa3cdaca2e7c1e69 100644 (file)
--- a/fs/nilfs2/the_nilfs.h
+++ b/fs/nilfs2/the_nilfs.h
@@ -46,6 +46,7 @@ enum {
 /**
  * struct the_nilfs - struct to supervise multiple nilfs mount points
  * @ns_flags: flags
+ * @ns_flushed_device: flag indicating if all volatile data was flushed
  * @ns_bdev: block device
  * @ns_sem: semaphore for shared states
  * @ns_snapshot_mount_mutex: mutex to protect snapshot mounts
@@ -103,6 +104,7 @@ enum {
  */
 struct the_nilfs {
        unsigned long           ns_flags;
+       int                     ns_flushed_device;
 
        struct block_device    *ns_bdev;
        struct rw_semaphore     ns_sem;
@@ -371,4 +373,24 @@ static inline int nilfs_segment_is_active(struct the_nilfs *nilfs, __u64 n)
        return n == nilfs->ns_segnum || n == nilfs->ns_nextnum;
 }
 
+static inline int nilfs_flush_device(struct the_nilfs *nilfs)
+{
+       int err;
+
+       if (!nilfs_test_opt(nilfs, BARRIER) || nilfs->ns_flushed_device)
+               return 0;
+
+       nilfs->ns_flushed_device = 1;
+       /*
+        * the store to ns_flushed_device must not be reordered after
+        * blkdev_issue_flush().
+        */
+       smp_wmb();
+
+       err = blkdev_issue_flush(nilfs->ns_bdev, GFP_KERNEL, NULL);
+       if (err != -EIO)
+               err = 0;
+       return err;
+}
+
 #endif /* _THE_NILFS_H */