fat: introduce mark_fsinfo_dirty helper

A preparation patch which introduces a 'mark_fsinfo_dirty()' helper
function which just sets the 's_dirt' flag to 1 so far.  I'll add more
code to this helper later, so I do not mark it as 'inline'.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/fat/fatent.c

@@ -308,6 +308,11 @@ void fat_ent_access_init(struct super_block *sb)
 	}
 }
 
+static void mark_fsinfo_dirty(struct super_block *sb)
+{
+	sb->s_dirt = 1;
+}
+
 static inline int fat_ent_update_ptr(struct super_block *sb,
 				     struct fat_entry *fatent,
 				     int offset, sector_t blocknr)
@@ -498,7 +503,7 @@ int fat_alloc_clusters(struct inode *inode, int *cluster, int nr_cluster)
 				sbi->prev_free = entry;
 				if (sbi->free_clusters != -1)
 					sbi->free_clusters--;
-				sb->s_dirt = 1;
+				mark_fsinfo_dirty(sb);
 
 				cluster[idx_clus] = entry;
 				idx_clus++;
@@ -520,7 +525,7 @@ int fat_alloc_clusters(struct inode *inode, int *cluster, int nr_cluster)
 	/* Couldn't allocate the free entries */
 	sbi->free_clusters = 0;
 	sbi->free_clus_valid = 1;
-	sb->s_dirt = 1;
+	mark_fsinfo_dirty(sb);
 	err = -ENOSPC;
 
 out:
@@ -587,7 +592,7 @@ int fat_free_clusters(struct inode *inode, int cluster)
 		ops->ent_put(&fatent, FAT_ENT_FREE);
 		if (sbi->free_clusters != -1) {
 			sbi->free_clusters++;
-			sb->s_dirt = 1;
+			mark_fsinfo_dirty(sb);
 		}
 
 		if (nr_bhs + fatent.nr_bhs > MAX_BUF_PER_PAGE) {
@@ -677,7 +682,7 @@ int fat_count_free_clusters(struct super_block *sb)
 	}
 	sbi->free_clusters = free;
 	sbi->free_clus_valid = 1;
-	sb->s_dirt = 1;
+	mark_fsinfo_dirty(sb);
 	fatent_brelse(&fatent);
 out:
 	unlock_fat(sbi);