md: change bitmap_unplug and others to void functions

bitmap_unplug only ever returns 0, so it may as well be void.  Two callers try
to print a message if it returns non-zero, but that message is already printed
by bitmap_file_kick.

write_page returns an error which is not consistently checked.  It always
causes BITMAP_WRITE_ERROR to be set on an error, and that can more
conveniently be checked.

When the return of write_page is checked, an error causes bitmap_file_kick to
be called - so move that call into write_page - and protect against recursive
calls into bitmap_file_kick.

bitmap_update_sb returns an error that is never checked.

So make these 'void' and be consistent about checking the bit.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/md/md.c

@@ -1640,7 +1640,6 @@ static void sync_sbs(mddev_t * mddev, int nospares)
 
 static void md_update_sb(mddev_t * mddev, int force_change)
 {
-	int err;
 	struct list_head *tmp;
 	mdk_rdev_t *rdev;
 	int sync_req;
@@ -1727,7 +1726,7 @@ static void md_update_sb(mddev_t * mddev, int force_change)
 		"md: updating %s RAID superblock on device (in sync %d)\n",
 		mdname(mddev),mddev->in_sync);
 
-	err = bitmap_update_sb(mddev->bitmap);
+	bitmap_update_sb(mddev->bitmap);
 	ITERATE_RDEV(mddev,rdev,tmp) {
 		char b[BDEVNAME_SIZE];
 		dprintk(KERN_INFO "md: ");

drivers/md/raid1.c

@@ -1526,8 +1526,7 @@ static void raid1d(mddev_t *mddev)
 			blk_remove_plug(mddev->queue);
 			spin_unlock_irqrestore(&conf->device_lock, flags);
 			/* flush any pending bitmap writes to disk before proceeding w/ I/O */
-			if (bitmap_unplug(mddev->bitmap) != 0)
-				printk("%s: bitmap file write failed!\n", mdname(mddev));
+			bitmap_unplug(mddev->bitmap);
 
 			while (bio) { /* submit pending writes */
 				struct bio *next = bio->bi_next;

drivers/md/raid10.c

@@ -1510,8 +1510,7 @@ static void raid10d(mddev_t *mddev)
 			blk_remove_plug(mddev->queue);
 			spin_unlock_irqrestore(&conf->device_lock, flags);
 			/* flush any pending bitmap writes to disk before proceeding w/ I/O */
-			if (bitmap_unplug(mddev->bitmap) != 0)
-				printk("%s: bitmap file write failed!\n", mdname(mddev));
+			bitmap_unplug(mddev->bitmap);
 
 			while (bio) { /* submit pending writes */
 				struct bio *next = bio->bi_next;

include/linux/raid/bitmap.h

@@ -262,7 +262,7 @@ int  bitmap_active(struct bitmap *bitmap);
 
 char *file_path(struct file *file, char *buf, int count);
 void bitmap_print_sb(struct bitmap *bitmap);
-int bitmap_update_sb(struct bitmap *bitmap);
+void bitmap_update_sb(struct bitmap *bitmap);
 
 int  bitmap_setallbits(struct bitmap *bitmap);
 void bitmap_write_all(struct bitmap *bitmap);
@@ -278,8 +278,8 @@ int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int d
 void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted);
 void bitmap_close_sync(struct bitmap *bitmap);
 
-int bitmap_unplug(struct bitmap *bitmap);
-int bitmap_daemon_work(struct bitmap *bitmap);
+void bitmap_unplug(struct bitmap *bitmap);
+void bitmap_daemon_work(struct bitmap *bitmap);
 #endif
 
 #endif