new helper: iterate_supers()

... and switch the simple "loop over superblocks and do something"
loops to it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 6 insertions, 19 deletions

diff --git a/fs/sync.c b/fs/sync.c
index f3f0a0e1948..d5369203f8e 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -77,31 +77,18 @@ int sync_filesystem(struct super_block *sb)
 }
 EXPORT_SYMBOL_GPL(sync_filesystem);
 
+static void sync_one_sb(struct super_block *sb, void *arg)
+{
+        if (!(sb->s_flags & MS_RDONLY) && sb->s_bdi)
+                __sync_filesystem(sb, *(int *)arg);
+}
 /*
  * Sync all the data for all the filesystems (called by sys_sync() and
  * emergency sync)
  */
 static void sync_filesystems(int wait)
 {
-        struct super_block *sb, *n;
-
-        spin_lock(&sb_lock);
-        list_for_each_entry_safe(sb, n, &super_blocks, s_list) {
-                if (list_empty(&sb->s_instances))
-                        continue;
-                sb->s_count++;
-                spin_unlock(&sb_lock);
-
-                down_read(&sb->s_umount);
-                if (!(sb->s_flags & MS_RDONLY) && sb->s_root && sb->s_bdi)
-                        __sync_filesystem(sb, wait);
-                up_read(&sb->s_umount);
-
-                /* restart only when sb is no longer on the list */
-                spin_lock(&sb_lock);
-                __put_super(sb);
-        }
-        spin_unlock(&sb_lock);
+        iterate_supers(sync_one_sb, &wait);
 }
 
 /*