vfs: factor sb iteration out of do_emergency_remount

The intent is to reduce code duplication with other code
iterating the list.

No functional changes.

Signed-off-by: Mateusz Guzik <mguzik@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/super.c b/fs/super.c
index 166c4ee..fd9c02f 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -574,6 +574,28 @@ void drop_super_exclusive(struct super_block *sb)
 }
 EXPORT_SYMBOL(drop_super_exclusive);
 
+static void __iterate_supers(void (*f)(struct super_block *))
+{
+       struct super_block *sb, *p = NULL;
+
+       spin_lock(&sb_lock);
+       list_for_each_entry(sb, &super_blocks, s_list) {
+               if (hlist_unhashed(&sb->s_instances))
+                       continue;
+               sb->s_count++;
+               spin_unlock(&sb_lock);
+
+               f(sb);
+
+               spin_lock(&sb_lock);
+               if (p)
+                       __put_super(p);
+               p = sb;
+       }
+       if (p)
+               __put_super(p);
+       spin_unlock(&sb_lock);
+}
 /**
  *     iterate_supers - call function for all active superblocks
  *     @f: function to call
@@ -881,33 +903,22 @@ cancel_readonly:
        return retval;
 }
 
-static void do_emergency_remount(struct work_struct *work)
+static void do_emergency_remount_callback(struct super_block *sb)
 {
-       struct super_block *sb, *p = NULL;
-
-       spin_lock(&sb_lock);
-       list_for_each_entry(sb, &super_blocks, s_list) {
-               if (hlist_unhashed(&sb->s_instances))
-                       continue;
-               sb->s_count++;
-               spin_unlock(&sb_lock);
-               down_write(&sb->s_umount);
-               if (sb->s_root && sb->s_bdev && (sb->s_flags & SB_BORN) &&
-                   !sb_rdonly(sb)) {
-                       /*
-                        * What lock protects sb->s_flags??
-                        */
-                       do_remount_sb(sb, SB_RDONLY, NULL, 1);
-               }
-               up_write(&sb->s_umount);
-               spin_lock(&sb_lock);
-               if (p)
-                       __put_super(p);
-               p = sb;
+       down_write(&sb->s_umount);
+       if (sb->s_root && sb->s_bdev && (sb->s_flags & SB_BORN) &&
+           !sb_rdonly(sb)) {
+               /*
+                * What lock protects sb->s_flags??
+                */
+               do_remount_sb(sb, SB_RDONLY, NULL, 1);
        }
-       if (p)
-               __put_super(p);
-       spin_unlock(&sb_lock);
+       up_write(&sb->s_umount);
+}
+
+static void do_emergency_remount(struct work_struct *work)
+{
+       __iterate_supers(do_emergency_remount_callback);
        kfree(work);
        printk("Emergency Remount complete\n");
 }